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Sökning: WFRF:(Kärrholm Johan)

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1.
  • Kärrholm, Johan, 1951, et al. (författare)
  • Effects on work resumption of a co-operation project in vocational rehabilitation. Systematic, multi-professional, client-centred and solution-oriented co-operation
  • 2006
  • Ingår i: Disabil Rehabil. - : Informa UK Limited. - 0963-8288 .- 1464-5165. ; 28:7, s. 457-67
  • Tidskriftsartikel (refereegranskat)abstract
    • PURPOSE: The present aim was to evaluate the effect of systematic multi-professional co-ordinated rehabilitation (the Stockholm Co-operation Project) on the number of days' sick leave during the first and second half-years after the rehabilitation co-ordination period, compared to the year before. Another aim was to evaluate the economic effects at national level. METHOD: A matched-pairs design was used. The study group was based on 64 rehabilitees employed by a public employer in Stockholm, who took part in a systematic multi-professional co-operation project. To obtain pairs, the 64 individuals were individually matched with 64 people who received conventionally organised rehabilitation. Thus, there were 128 subjects altogether. RESULTS: The study group had substantially less sick leave days per month than the comparison group during the second half-year after the rehabilitation co-ordination period. The effect was even greater in a subgroup with more previous sick leave. During the first half-year after the intervention the comparison group had relatively more sick leave. No effect was found for a subgroup with less previous sick leave. The economic benefit of the intervention was estimated to 1,278 euros per month and person based on the whole group, and to 2,405 euros per month and person based on those with more sick leave. CONCLUSIONS: People who undergo co-ordinated rehabilitation have more working days after the intervention period than those with conventional rehabilitation. This way for rehabilitation actors to co-operate gives better outcomes for rehabilitation cases with long previous sick leave, but not for cases with less previous sick leave. It also generates economic gains at several levels.
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2.
  • Saari, Tuuli, 1965, et al. (författare)
  • Changed gait pattern in patients with total knee arthroplasty but minimal influence of tibial insert design: gait analysis during level walking in 39 TKR patients and 18 healthy controls
  • 2005
  • Ingår i: Acta Orthop. - : Medical Journals Sweden AB. - 1745-3674. ; 76:2, s. 253-60
  • Tidskriftsartikel (refereegranskat)abstract
    • INTRODUCTION: Previous radiostereometric studies have revealed abnormal anterior-posterior translation of the femur in patients operated with AMK (DePuy, Johnson and Johnson, Leeds, UK) total knee arthroplasty (TKA). Based on these observations, we hypothesized that patients with TKA have an abnormal gait pattern, and that there are differences in kinematics depending on the design of the tibial joint area. METHOD: We used a gait analysis system to evaluate the influence of joint area design on the kinematics of the hip and knee during level walking. 39 TKA patients (42 knees) and 18 healthy age-matched controls were studied. Patients with 5 degrees varus/valgus alignment or less were randomized to receive either a relatively flat or a concave tibial insert with retention of the posterior cruciate ligament. Patients who had more than 5 degrees varus-valgus alignment and/or extension defect of 10 degrees or more were randomized to receive the concave or a posterior-stabilized tibial component with resection of the posterior cruciate ligament. RESULTS: Patients with TKA tended to have less hip and knee extension and decreased knee and hip extension moment than controls. They also tended to walk more slowly. TKA altered the gait pattern, but choice of implant design had little influence. INTERPRETATION: In patients with a similar degree of degenerative joint disease and within the limits of the constraints offered by the prostheses under study, the choice of joint area constraint has little influence on the gait pattern.
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3.
  • Saari, Tuuli, 1965, et al. (författare)
  • Influence of polyethylene constraint on tibial component fixation in total knee arthroplasty: follow-up report after 5 years
  • 2006
  • Ingår i: J Arthroplasty. - : Elsevier BV. - 0883-5403. ; 21:7, s. 1032-7
  • Tidskriftsartikel (refereegranskat)abstract
    • The influence of articulating surface design of AMK total knee prosthesis (DePuy, Johnson & Johnson) on migration and radiographic outcome at 5 years was evaluated. The knees were randomly allocated to receive a flat or a concave insert with retention of the posterior cruciate ligament when preoperative deformity was less severe and either a concave or a posterior-stabilized insert with resection of the posterior cruciate ligament when deformity was more pronounced. In 64 knees, migration was measured with radiostereometry. The posterior-stabilized component displayed more varus-valgus tilting than the concave insert. Other statistically significant differences in migration were not seen. Radiolucent lines were frequently seen without differences between prosthesis groups.
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4.
  • Saari, Tuuli, 1965, et al. (författare)
  • Joint area constraint had no influence on bone loss in proximal tibia 5 years after total knee replacement
  • 2007
  • Ingår i: J Orthop Res. - : Wiley. - 0736-0266. ; 25:6, s. 798-803
  • Tidskriftsartikel (refereegranskat)abstract
    • After total knee replacement (TKR) the bone mineral density (BMD) decreases in the proximal tibia. Our aim was to evaluate if changes in constraint of the cemented AMK TKR (DePuy, Johnson & Johnson, Leeds, UK) had any effect on postoperative bone remodeling in the proximal tibia. We used dual-energy X-ray absorptiometry in 43-53 knees to record changes in BMD in three regions of interest around the tibial component up to 5 years after operation with the AMK (DePuy) TKR. The knees had been randomly allocated to receive a flat or a concave tibial insert with retention of the posterior cruciate ligament when preoperative deformity was less severe, and either a concave or a posterior-stabilized (PS) insert with resection of the posterior cruciate ligament when deformity was more pronounced. All designs were associated with loss of BMD in the proximal tibia. The mean bone loss varied from 5 to 23% depending on the region of interest. There were no statistically significant differences between the groups, and the alteration of tibial insert constraint did not influence the bone remodeling. However, low precision values may have impaired the detection of differences.
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5.
  • Saari, Tuuli, 1965, et al. (författare)
  • Posterior stabilized component increased femoral bone loss after total knee replacement. 5-year follow-up of 47 knees using dual energy X-ray absorptiometry
  • 2006
  • Ingår i: Knee. - 0968-0160. ; 13:6, s. 435-9
  • Tidskriftsartikel (refereegranskat)abstract
    • After total knee replacement (TKR) bone mineral density (BMD) commonly decreases behind the anterior flange of the femoral component, which may increase the risk for supracondylar fracture. Our aim was to evaluate if changes in femoral design and joint area constraint had any effect on the postoperative bone remodeling in the distal femur. We used dual-energy X-ray absorptiometry in 47 knees up to 5 years after operation with the AMK (DePuy, Johnson and Johnson Leeds, UK) TKR. The knees had been randomly allocated to receive a flat or a concave tibial insert with retention of the posterior cruciate ligament when preoperative deformity was less severe, and either a concave or a posterior-stabilized (PS) insert with resection of the posterior cruciate ligament when deformity was more pronounced. The most pronounced relative reduction (15-38%) in bone mineral density (BMD) was seen posterior to the anterior flange. There were no significant differences in relative change in BMD between flat and concave inserts. Knees operated with PS inserts had more reduction posterior to the flange than knees with concave inserts in the subgroup with more advanced preoperative deformity (23% and 38% respectively). Use of posterior stabilized insert may increase the risk of supracondylar fracture compared to concave insert in knees with advanced preoperative deformity.
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6.
  • Saari, Tuuli, 1965, et al. (författare)
  • The effect of tibial insert design on rising from a chair; motion analysis after total knee replacement
  • 2004
  • Ingår i: Clin Biomech (Bristol, Avon). - : Elsevier BV. - 0268-0033. ; 19:9, s. 951-6
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: There are few previous studies of sit-to-stand movement following total knee arthroplasty. Aim of the study was to test the hypotheses that total knee replacement alters the maximum trunk, hip, knee and ankle flexion-extension movements during chair rising, and that the design of the tibial plateau has small influence on the kinematics. METHODS: A motion analysis system was used to evaluate kinematics of the trunk, hip, knee and ankle when rising from one chair and sitting down on another. Patients with 5 degrees varus/valgus alignment or less received either a flat or a concave tibial insert with retention of the posterior cruciate ligament. Patients who had more malalignment and /or extension defect of 10 degrees or more were randomized to receive the concave or a posterior-stabilized tibial component with resection of the posterior cruciate ligament. The two groups of patients operated with and without resection of the posterior cruciate ligament were analysed separately and compared with a control group. 28 patients (29 knees) and 16 controls were in the final analysis. FINDINGS: Decreased hip and knee extension compared to the controls was seen, but there were no statistically significant differences in kinematics between the designs. INTERPRETATION: Choice of implant design in total knee arthroplasty had no detectable effects on kinematics of hip and knee joints during sit-to-stand movement.
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7.
  • Saari, Tuuli, 1965, et al. (författare)
  • Total knee replacement influences both knee and hip joint kinematics during stair climbing
  • 2004
  • Ingår i: Int Orthop. - : Springer Science and Business Media LLC. - 0341-2695. ; 28:2, s. 82-6
  • Tidskriftsartikel (refereegranskat)abstract
    • A gait analysis system was used to evaluate the kinematics of the hip and knee during stair ascending and descending after operation with total knee replacement.Patients with 5 degrees varus/valgus alignment or less were selected randomly to receive either a flat or a concave tibial component with retention of the posterior cruciate ligament. Patients who had more than 5 degrees varus/valgus alignment and/or an extension defect of 10 degrees or more were selected randomly to receive the concave or posterior-stabilized tibial component with resection of the posterior cruciate ligament. Twenty patients and 17 controls were studied 1-2 years after the operation. Patients had abnormal kinematics during stair ascending and descend-ing. Both knee extension and flexion were reduced. Hip extension tended to decrease, and decreased hip extension moment was noted.
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8.
  • Stenberg, Johan, et al. (författare)
  • Quantitative proteomics reveals regulatory differences in the chondrocyte secretome from human medial and lateral femoral condyles in osteoarthritic patients
  • 2013
  • Ingår i: Proteome Science. - : Springer Science and Business Media LLC. - 1477-5956. ; 11:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Osteoarthritis (OA) is a destructive joint disease and there are no known biomarkers available for an early diagnosis. To identify potential disease biomarkers and gain further insight into the disease mechanisms of OA we applied quantitative proteomics with SILAC technology on the secretomes from chondrocytes of OA knees, designated as high Mankin (HM) scored secretome. A quantitative comparison was made between the secretomes of the medial and lateral femur condyle chondrocytes in the same knee since the medial femur condyle is usually more affected in OA than the lateral condyle, which was confirmed by Mankin scoring. The medial/lateral comparison was also made on the secretomes from chondrocytes taken from one individual with no clinically apparent joint-disease, designated as low Mankin (LM) scored secretome. Results: We identified 825 proteins in the HM secretome and 69 of these showed differential expression when comparing the medial and lateral femoral compartment. The LM scored femoral condyle showed early signs of OA in the medial compartment as assessed by Mankin score. We here report the identification and relative quantification of several proteins of interest for the OA disease mechanism e.g. CYTL1, DMD and STAB1 together with putative early disease markers e.g. TIMP1, PPP2CA and B2M. Conclusions: The present study reveals differences in protein abundance between medial/lateral femur condyles in OA patients. These regulatory differences expand the knowledge regarding OA disease markers and mechanisms.
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9.
  • Uvehammer, Johan, 1953, et al. (författare)
  • Cemented versus hydroxyapatite fixation of the femoral component of the Freeman-Samuelson total knee replacement: A RADIOSTEREOMETRIC ANALYSIS
  • 2007
  • Ingår i: J Bone Joint Surg Br. - 0301-620X. ; 89:1, s. 39-44
  • Tidskriftsartikel (refereegranskat)abstract
    • We have carried out a radiostereometric study of 50 patients (54 knees) with osteoarthritis of the knee who were randomly allocated to receive a cemented or a hydroxyapatite-coated femoral component for total knee replacement. The patients were also stratified to receive one of three types of articulating surface (standard, rotating platform, Freeman-Samuelson (FS)1000) all based on the Freeman-Samuelson design. The tibial components were cemented in all cases. Radiostereometry was performed post-operatively and at 3, 12 and 24 months. The analysis was restricted to rotation of the femoral component over time. After two years, rotation of the femoral components in the transverse, longitudinal and sagittal planes did not differ between the cemented and the hydroxyapatite-coated implants (p = 0.2 to 0.9). In total knee replacements with a rotating platform, the femoral component tended to tilt more posteriorly than in the other two designs, regardless of the choice of fixation (cemented or hydroxyapatite-coated, p = 0.04). The standard version of the femoral component, whether cemented or hydroxyapatite-coated, rotated more into valgus than was observed with the rotating-platform and FS1000 designs (p = 0.005). The increased constraint provided by the FS1000 component did not appear to have any adverse effect on fixation of the femoral component.
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10.
  • Uvehammer, Johan, 1953, et al. (författare)
  • Influence of joint area design on tibial component migration: comparison among a fixed symmetrical, asymmetrical, and moveable bearing
  • 2007
  • Ingår i: J Knee Surg. - 1538-8506. ; 20:1, s. 20-6
  • Tidskriftsartikel (refereegranskat)abstract
    • Fifty-four knees (50 patients) were allocated to three different tibial polyethylene inserts (standard/rotating platform/FS1000) in the Freeman-Samuelson (Finsbury Orthopaedics Ltd, Surrey, United Kingdom) total knee arthroplasty. The FS1000 design has a spherical medial and a roller-in-trough configuration laterally. Radiostereometric examinations were done postoperatively and after 3, 12, and 24 months. The median migration of the metal-backing and the Hospital for Special Surgery scores did not differ between the three groups. At 2 years, the median external/ internal displacements for the rotating platforms were 2.8 degrees and 0.2 degrees, respectively (rotating platforms versus standard inserts/rotating platforms versus FS1000: P < .0005). Longitudinal rotations above the detection limits for radiostereometry were observed in some of the fixed implants (standard and FS1000 designs), indicating conditions for backside wear.
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11.
  • Axelsson, Peter, 1963, et al. (författare)
  • Forearm Torque and Lifting Strength: Normative Data
  • 2018
  • Ingår i: Journal of Hand Surgery-American Volume. - : Elsevier BV. - 0363-5023. ; 43:7
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose To establish reference values for new methods designed to quantitatively measure forearm torque and lifting strength and to compare these values with grip strength. Methods A total of 499 volunteers, 262 males and 237 females, aged 15 to 85 (mean, 44) years, were tested for lifting strength and forearm torque with the Kern and Baseline dynamometers. These individuals were also tested for grip strength with a Jamar dynamometer. Standardized procedures were used and information about sex, height, weight, hand dominance, and whether their work involved high or low manual strain was collected. Results Men had approximately 70% higher forearm torque and lifting strength compared with females. Male subjects aged 26 to 35 years and female subjects aged 36 to 45 years showed highest strength values. In patients with dominant right side, 61% to 78% had a higher or equal strength on this side in the different tests performed. In patients with dominant left side, the corresponding proportions varied between 41% and 65%. There was a high correlation between grip strength and forearm torque and lifting strength. Sex, body height, body weight, and age showed a significant correlation to the strength measurements. In a multiple regression model sex, age (entered as linear and squared) could explain 51% to 63% of the total variances of forearm torque strength and 30% to 36% of lifting strength. Conclusions Reference values for lifting strength and forearm torque to be used in clinical practice were acquired. Grip strength has a high correlation to forearm torque and lifting strength. Sex, age, and height can be used to predict forearm torque and lifting strength. Prediction equations using these variables were generated. Copyright (C) 2018 by the American Society for Surgery of the Hand. All rights reserved.
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12.
  • Axelsson, Peter, 1963, et al. (författare)
  • New Methods to Assess Forearm Torque and Lifting Strength: Reliability and Validity
  • 2018
  • Ingår i: Journal of Hand Surgery-American Volume. - : Elsevier BV. - 0363-5023. ; 43:9
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose To determine the repeatability and validity of new methods designed to objectively measure forearm torque and lifting strength in a clinical setting. Methods Twenty-eight healthy volunteers, 19 women and 9 men, were tested for lifting strength and forearm torque with the Kern and Baseline dynamometers. Two raters tested each participant on 3 occasions in the standing position. One of the raters also examined 15 subjects, 3 times, for forearm torque in the seated position and for lifting strength and forearm torque by the Work Simulator II, Baltimore Therapeutic Equipment (BTE II). Intraclass correlation coefficients (ICC) model 2,1 was used to calculate ICCs for intra- and intenater reliability. The same ICC model and Bland-Altman plots were used to analyze the validity and agreement between the new test methods and the BTE II equipment and for comparison between tests performed in the standing and seated positions. Results Intra- and interrater reliability for forearm torque measurements with both the Baseline and the BTE II demonstrated ICCs between 0.88 and 0.96. The comparison between the Baseline and the BTE equipment yielded lower ICCs of 0.74 to 0.88 but they were still substantial and in good agreement. The ICCs for torques recorded in the standing and seated position were 0.89 to 0.96. Lifting strength, measured in 3 different positions of forearm rotation, yielded ICC values between 0.84 and 0.96 for both raters and with both the Kern and the BTE II instruments. Similarly, comparisons between the Kern and the BTE II methods showed ICC values between 0.91 and 0.95. Conclusions Both the Baseline and the Kern dynamometers demonstrated excellent intra- and interrater repeatability. Except for forearm torque test in direction of pronation, which had a slightly lower ICC of 0.74, our new methods were valid when the BTE II was used as the reference standard. Assessments in the standing or seated position for torque measurements made little difference. Thus, we found the quality of measurements performed with our new methods sufficient for future studies of forearm torque and lifting strength. Copyright (C) 2018 by the American Society for Surgery of the Hand. All rights reserved.
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13.
  • Axelsson, Peter, 1963, et al. (författare)
  • Ulnar Head Replacement: 21 Cases; Mean Follow-Up, 7.5 Years.
  • 2015
  • Ingår i: The Journal of hand surgery. - : Elsevier BV. - 1531-6564 .- 0363-5023. ; 40:9, s. 1731-8
  • Tidskriftsartikel (refereegranskat)abstract
    • To report clinical and radiographic outcomes for the Herbert ulnar head prosthesis after a mean of 7.5 years (range, 2.0-12.5 years).
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14.
  • Axelsson, Peter, 1963, et al. (författare)
  • Validity and Responsiveness of Forearm Strength Measurements in the Evaluation of Distal Radioulnar Joint Implant Arthroplasty
  • 2020
  • Ingår i: Journal of Hand Surgery. - : Elsevier BV. - 0363-5023. ; 45:8
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: To assess the responsiveness of forearm strength tests and to correlate the change to grip strength and a patient-reported outcome measure used for evaluation of distal radioulnar joint (DRUJ) implant arthroplasty. Methods: We performed a retrospective review of 18 patients treated with Herbert (n = 12) and Scheker (n = 6) DRUJ implants. Patients who had undergone the various measurements of arm and grip strength both before surgery and after a minimum follow-up of 1 year were included. Our primary aim was to compare the responsiveness of grip strength with our new methods for measuring forearm torque and lifting strength. The secondary aim was to correlate observed changes in strength measurements to change in a patient-reported outcome measure with use of the patient-reported wrist evaluation (PRWE). Measurements of grip strength, forearm torque, and lifting strength were performed with the Jamar dynamometer and the Kern and Baseline instruments. Preoperative values were compared with 1-year values. Results: Standardized response mean and effect size values were higher for forearm torque than for grip strength. Change in forearm torque and lifting strength had a moderate to strong correlation with change in PRWE. The correlation between grip strength and PRWE was weak. Conclusions: Forearm torque measurements were better than grip strength in detecting changes after DRUJ arthroplasty. It also had a stronger correlation to patient-reported outcome, measured with the PRWE. Clinical relevance: Forearm torque testing may add further information to the evaluation of DRUJ disorders and their treatments. These tests can provide quantifiable data on the patient's ability to perform various tasks requiring physical strength. © 2020 American Society for Surgery of the Hand
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15.
  • Bergh, Camilla, et al. (författare)
  • Increased risk of revision in patients with non-traumatic femoral head necrosis.
  • 2014
  • Ingår i: Acta orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 85:1, s. 11-17
  • Tidskriftsartikel (refereegranskat)abstract
    • Background and purpose Previous studies of patients who have undergone total hip arthroplasty (THA) due to femoral head necrosis (FHN) have shown an increased risk of revision compared to cases with primary osteoarthritis (POA), but recent studies have suggested that this procedure is not associated with poor outcome. We compared the risk of revision after operation with THA due to FHN or POA in the Nordic Arthroplasty Register Association (NARA) database including Denmark, Finland, Norway, and Sweden. Patients and methods 427,806 THAs performed between 1995 and 2011 were included. The relative risk of revision for any reason, for aseptic loosening, dislocation, deep infection, and periprosthetic fracture was studied before and after adjustment for covariates using Cox regression models. Results 416,217 hips with POA (mean age 69 (SD 10), 59% females) and 11,589 with FHN (mean age 65 (SD 16), 58% females) were registered. The mean follow-up was 6.3 (SD 4.3) years. After 2 years of observation, 1.7% in the POA group and 3.0% in the FHN group had been revised. The corresponding proportions after 16 years of observation were 4.2% and 6.1%, respectively. The 16-year survival in the 2 groups was 86% (95% CI: 86-86) and 77% (CI: 74-80). After adjusting for covariates, the relative risk (RR) of revision for any reason was higher in patients with FHN for both periods studied (up to 2 years: RR = 1.44, 95% CI: 1.34-1.54; p < 0.001; and 2-16 years: RR = 1.25, 1.14-1.38; p < 0.001). Interpretation Patients with FHN had an overall increased risk of revision. This increased risk persisted over the entire period of observation and covered more or less all of the 4 most common reasons for revision.
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16.
  • Bojan, Alicja J., 1980, et al. (författare)
  • Three-dimensional bone-implant movements in trochanteric hip fractures. Precision and accuracy of radiostereometric analysis in a phantom model.
  • 2015
  • Ingår i: Journal of orthopaedic research : official publication of the Orthopaedic Research Society. - : Wiley. - 1554-527X. ; 33:5, s. 705-11
  • Tidskriftsartikel (refereegranskat)abstract
    • The accuracy and precision of RSA was evaluated in the experimental study of screw cut-out complication after fixation of trochanteric fractures. A plastic bone model of a two-part trochanteric fracture was constructed with a Gamma nail implant incorporating RSA markers. The femoral head fragment was attached to a separate rotational table and the femoral shaft was mounted on the micrometer. Three main motions were simulated: femoral head translation and rotation along the axis of the lag screw and fracture fragment translation along anatomical axes. Accuracy and precision were determined according to ISO 16087 and ASTM standard F2385-04. Translations along the lag screw axis were measured with a precision within±0.14mm and an accuracy within±0.03mm. With simultaneous translations along all three anatomical axes, lowest precision was measured for the x-axis (±0.29mm, 0.07mm respectively), but improved when analyzed as a vector (±0.08mm, 0.03mm). The precision and accuracy of femoral head rotations were within 0.5° and 0.18°, respectively. The resolution of the RSA method tested in this model was high, though it varied depending on the type of analyzed motion. This information is valuable when selecting and interpreting outcome parameters evaluating implant migration and osteosynthesis stability in future clinical RSA studies. This article is protected by copyright. All rights reserved.
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17.
  • Bojan, Alicja J., 1980, et al. (författare)
  • Trochanteric fracture-implant motion during healing - A radiostereometry (RSA) study
  • 2018
  • Ingår i: Injury-International Journal of the Care of the Injured. - : Elsevier BV. - 0020-1383. ; 49:3, s. 673-679
  • Tidskriftsartikel (refereegranskat)abstract
    • Cut-out complication remains a major unsolved problem in the treatment of trochanteric hip fractures. A better understanding of the three-dimensional fracture-implant motions is needed to enable further development of clinical strategies and countermeasures. The aim of this clinical study was to characterise and quantify three-dimensional motions between the implant and the bone and between the lag screw and nail of the Gamma nail. Radiostereometry Analysis (RSA) analysis was applied in 20 patients with trochanteric hip fractures treated with an intramedullary nail. The following three-dimensional motions were measured postoperatively, at 1 week, 3, 6 and 12 months: translations of the tip of the lag screw in the femoral head, motions of the lag screw in the nail, femoral head motions relative to the nail and nail movements in the femoral shaft. Cranial migration of the tip of the lag screw dominated over the other two translation components in the femoral head. In all fractures the lag screw slid laterally in the nail and the femoral head moved both laterally and inferiorly towards the nail. All femoral heads translated posteriorly relative to the nail, and rotations occurred in both directions with median values close to zero. The nail tended to retrovert in the femoral shaft. Adverse fracture-implant motions were detected in stable trochanteric hip fractures treated with intramedullary nails with high resolution. Therefore, RSA method can be used to evaluate new implant designs and clinical strategies, which aim to reduce cut-out complications. Future RSA studies should aim at more unstable fractures as these are more likely to fail with cut-out. (C) 2018 Elsevier Ltd. All rights reserved.
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18.
  • Bragdon, Charles R, 1959, et al. (författare)
  • Comparison of femoral head penetration using RSA and the Martell method
  • 2006
  • Ingår i: Clin Orthop Relat Res. - 0009-921X. ; 448, s. 52-7
  • Tidskriftsartikel (refereegranskat)abstract
    • Radiostereometry has high precision and accuracy measuring polyethylene wear in total hip arthroplasty but requires a specialized setup. The Martell method is simpler and can be used on larger populations. The hypothesis that the radiostereometry analysis and the Martell analysis would yield comparable wear data from the same group of patients having total hip arthroplasty was tested. A group of twenty-five total hip arthroplasty patients who had both radiostereometry and standard anterior-posterior pelvic and cross-table lateral radiographs of sufficient quality for analysis were identified. The films were taken at postoperative periods of 6 weeks, 1 year, 2 years, and 5 years. Femoral head penetration was measured by both methods at each time point. The median penetration rates measured by each method decreased over time. Penetration results were affected by method of analysis, time, and dimension, with greater penetration for Martell compared with radiostereometry at each time point, greater penetration with increasing time for each method, and larger three-dimensional magnitude compared with two-dimensional analysis. LEVEL OF EVIDENCE: Case series Level IV. See Guidelines for Authors for a complete description of levels of evidence.
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19.
  • Bragdon, Charles R, 1959, et al. (författare)
  • Comparison of two digital radiostereometric analysis methods in the determination of femoral head penetration in a total hip replacement phantom
  • 2004
  • Ingår i: J Orthop Res. - : Wiley. - 0736-0266. ; 22:3, s. 659-64
  • Tidskriftsartikel (refereegranskat)abstract
    • Radiostereometric analysis (RSA) has been used extensively to evaluate the magnitude and direction of penetration of the femoral head into the acetabular component of a total hip replacement as a result of polyethylene wear and creep. The accuracy and precision of an RSA study depends on several factors, including the radiographic technique, the analytical software, and the positioning of the tantalum markers. This study had three sequential purposes. First, an in vitro phantom model was used to quantify the accuracy and precision of digital images versus conventional radiography in RSA measurements of penetration of the femoral head into the acetabular shell in a total hip replacement. The Umea RSA software package was used for analysis of both the conventional films, which were digitized at a resolution of 300 DPI, and digital radiographs, which were converted from a DICOM format at a resolution of 218 DPI. Digital radiography was found to be superior. Next, two methods of RSA analysis currently in use for determining femoral head penetration into polyethylene of total joint replacements were compared. Using the phantom model, we compared the Umea RSA system (Biomedical Innovations AB) to the RSA-CMS (RSA Clinical Measurement Solution) and in both cases used the digital radiographs. The Umea RSA system was found to be superior. Finally, two methods of marking the position of the acetabular component with tantalum beads were compared: one in which beads were inserted into previously described towers protruding from the back of the acetabular shell and another in which beads were placed into the peripheral flange of the polyethylene liner using the Umea RSA analysis system of the digital radiographs. The results using the two marker configurations were similar.
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20.
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21.
  • Bragdon, Charles R, 1959, et al. (författare)
  • Standing versus supine radiographs in RSA evaluation of femoral head penetration
  • 2006
  • Ingår i: Clin Orthop Relat Res. - 0009-921X. ; 448, s. 46-51
  • Tidskriftsartikel (refereegranskat)abstract
    • Evaluation of polyethylene acetabular component wear in total hip arthroplasties commonly is performed using serial radiographs of the hip by measuring the change in the location of the center of the femoral head in relation to the acetabular component. Of the different methods currently used for this purpose, radiostereometric analysis (RSA) is considered the most accurate and precise. In all such radiographic studies, it is assumed the femoral head is seated into the deepest portion of the acetabular component during all radiographic examinations. Although most radiographs used for wear measurements are taken with the patient supine, we questioned whether standing radiographs, with substantial joint load, are better suited for these measurements. We evaluated two groups of patients having total hip arthroplasty who had radiostereometric radiographs taken in supine and standing positions. The average femoral head penetration that occurred between the 6-month and 2-year time interval was measured with radiographs taken in the standing or supine position. We found no difference between the average total femoral head penetration when using supine or standing radiographs.
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22.
  • Brynjólfsson, Siggeir Fannar, et al. (författare)
  • Long-lived plasma cells in human bone marrow can be either CD191(+) or CD19(-)
  • 2017
  • Ingår i: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 1:13, s. 835-838
  • Tidskriftsartikel (refereegranskat)abstract
    • Long-lived plasma cells secreting vaccinia-specific antibodies are detected in human bone marrow >35 years after the eradication of smallpox. Long-lived plasma cells secreting vaccinia-specific antibodies are still able to express the B-lymphocyte antigen CD19.
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23.
  • Börlin, Niclas, 1968-, et al. (författare)
  • Radiostereometry Based On Digitized Radiographs
  • 1997
  • Ingår i: Proceedings of the 43rd Annual Meeting of The Orthopaedic Research Society. ; , s. 626-626
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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24.
  • Börlin, Niclas, 1968-, et al. (författare)
  • The precision of radiostereometric measurements : manual vs. digital measurements
  • 2002
  • Ingår i: Journal of Biomechanics. - : Elsevier. - 0021-9290 .- 1873-2380. ; 35:1, s. 69-79
  • Tidskriftsartikel (refereegranskat)abstract
    • The precision of digital vs. manual radiostereometric measurements in total hip arthroplasty was evaluated using repeated stereoradiographic exposures with an interval of 10–15 min. Ten Lubinus SP2 stems cemented into bone specimens and 12 patients with the same stem design were used to evaluate the precision of stem translations and rotations. The precision of translations and rotations of the cup and femoral head penetration was studied in 12 patients with whole polyethylene cups.The use of a measurement method based on digitised radiographs improved the precision for some of the motion parameters, whereas many of them did not change. A corresponding pattern was observed for both the intra- and interobserver error. Of the wear parameters, the most pronounced improvements were the 3D wear and in the proximal-distal direction, although the anterior-posterior precision was also improved. The mean errors of rigid body and elliptic fitting decreased in all evaluations but one, consistent with a more reproducible identification of the markers centres and the edge of the femoral head.Increased precision of radiostereometric measurements may be used to increase the statistical power of future randomised studies and to study new fields in orthopaedics requiring higher precision than has been available with RSA based on manual measurements.
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25.
  • Cassuto, Jean, et al. (författare)
  • Concerted actions by MMPs, ADAMTS and serine proteases during remodeling of the cartilage callus into bone during osseointegration of hip implants.
  • 2020
  • Ingår i: Bone reports. - : Elsevier BV. - 2352-1872. ; 13
  • Tidskriftsartikel (refereegranskat)abstract
    • Although the number of patients undergoing total hip arthroplasty is constantly on the rise, we only have limited knowledge of the molecular mechanisms necessary for successful osseointegration of implants or the reasons why some fail. Understanding the spatiotemporal characteristics of signaling pathways involved in bone healing of implants is therefore of particular importance for our ability to identify factors causing implants to fail. The current study investigated the role of three families of proteases, i.e. MMPs (matrix metalloproteinases), ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) and serine proteases, as well as their endogenous inhibitors during osseointegration of hip implants that have endured two decades of use without clinical or radiological signs of loosening.Twenty-four patients that had undergone primary THA due to one-sided osteoarthritis (OA) were monitored during 18years (Y) with repeated measurements of plasma biomarkers, clinical variables and radiographs. All implants were clinically and radiographically well-fixed throughout the follow-up. Eighty-one healthy donors divided in three gender and age-matched groups and twenty OA patients awaiting THA, served as controls. Plasma was analyzed for MMP-1, -2, -3, -8, -9, -10, -13, -14, tissue inhibitor of metalloproteinase (TIMP)-1, -2, -3, ADAMTS4, ADAMTS5, the serine proteases neutrophil elastase (NE), proteinase 3 (PR3) and their endogenous inhibitors, secretory leucocyte proteinase inhibitor (SLPI), trappin-2/elafin and serpina1 (α-1 antitrypsin). Cartilage turnover was monitored using two markers of cartilage synthesis, type II procollagen and PIICP (procollagen II C-terminal propeptide), and two markers of cartilage degradation, CTX-II (C-terminal telopeptide fragments of type II collagen) and split products of aggrecan (G1-IGD-G2).MMP-1, MMP-9, ADAMTS4, NE and PR3 were above healthy in presurgery OA patients but returned to the level of healthy within 6weeks (W) after surgery. MMPs and serine proteases were counter-regulated during this phase by TIMP-1, SLPI and trappin-2/elafin. Type II procollagen, PIICP and CTX-II increased to a peak 6W after surgery with a gradual return to the level of controls within weeks. Significant increases by MMP-8, MMP-9, ADAMTS4, ADAMTS5, NE, PR3 and the protease inhibitors, TIMP-3 and serpina1, were seen 5 Y after hip arthroplasty paralleled by a sharp increase in the levels of the cartilage degradation markers, CTX-II and G1-IGD-G2. All the above mediators were normalized before 18 Y, except MMP-1 and MMP-9 that remained above healthy at 18 Y. MMP-14 increased immediately after surgery and remained elevated until 5 Y postsurgery before returning to the level of controls at 7 Y.Notwithstanding temporal differences, the molecular processes of bone repair in arthroplasty patients show great spatial similarities with the classical phases of fracture repair as previously shown in animal models. Cartilagenous callus, produced and remodeled early after hip arthroplasty, is replaced with bone 5 Y to7 Y after surgery by the concerted actions of MMP-8, MMP-9, ADAMTS4, ADAMTS5, NE and PR3, thus suggesting that a complex regulatory cross-talk may exist between different families of proteases during this transitional phase of cartilage degradation. Regulation and fine-tuning of cartilage remodeling by MMPs and ADAMTS is controlled by TIMP-3 whereas serine proteases are regulated by serpina1. Increased MMP-1 and MMP-9 beyond 10Y post-THA support a role during coupled bone remodeling.
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26.
  • Cassuto, Jean, et al. (författare)
  • The importance of BMPs and TGF-βs for endochondral bone repair – A longitudinal study in hip arthroplasty patients
  • 2023
  • Ingår i: Bone Reports. - 2352-1872. ; 19
  • Tidskriftsartikel (refereegranskat)abstract
    • Introduction: Osseointegration of hip implants, although a decade-long process, shows striking similarities with the four major phases of endochondral bone repair. In the current study we investigated the spatiotemporal involvement of bone morphogenic proteins (BMPs) and transforming growth factor betas (TGF-βs) throughout the process of bone repair leading to successfully osseointegrated hip implants. Materials and methods: Twenty-four patients that had undergone primary total hip arthroplasty (THA) due to one-sided osteoarthritis (OA) were investigated during a period of 18 years (Y) with repeated measurements of plasma biomarkers as well as clinical and radiological variables. All implants were clinically and radiographically well anchored throughout the follow-up. Eighty-one healthy donors divided in three gender- and age-matched groups and twenty OA patients awaiting THA, served as controls. Plasma was analyzed for BMP-1, -2, -3, -4, -6, -7 -9 and TGF-β1, -β2, -β3 by use of a high-sensitivity and wide dynamic range electrochemiluminescence technique allowing for detection of minor changes. Results: Spatiotemporal changes during the follow-up are presented in the context of the four phases of endochondral bone repair shown in earlier studies and transposed to the current study based on similarities in biomarker responses. Phase 1: Primary proinflammatory phase lasting from surgery until day 7, Phase 2: Chondrogenic phase from day 7 until 18 months postsurgery, Phase 3: Secondary proinflammatory and cartilage remodeling phase lasting from 18 months until 7Y, Phase 4: coupled bone remodeling from 7Y until 18Y postsurgery. BMP-1 increased sharply shortly after surgery and remained significantly above healthy during the chondrocyte recruitment, proliferation, and hypertrophy phases with a subsequent return to control level at 5Y postsurgery. BMP-2 was above healthy controls before surgery and 1 day after surgery before decreasing to control level and remaining there throughout the follow-up. BMP-3 was at control level from presurgery until 6M after surgery when it increased to a peak at 2Y during the cartilage hypertrophy phase followed by a gradual decrease to control level at 10Y during the phase of bone formation. In the following, BMP-3 decreased below controls to a nadir 15Y postsurgery during coupled bone remodeling. BMP-4 was at control level from presurgery until 10Y postsurgery when it increased to a sharp peak at 15Y after surgery followed by a return to the level of healthy at 18Y. BMP-6 did not differ from healthy during the follow-up. BMP-7 was at control level from presurgery until 1Y postsurgery before gradually increasing to a peak at 10Y during the early phase of osteogenesis with a gradual return to control level at 18Y during the phase of coupled bone remodeling. BMP-9 was above OA before surgery followed by a decrease to basal level on day 1 after surgery and a renewed increase to a plateau above controls lasting from 6 W until returning to the level of healthy at 18Y postsurgery, i.e., throughout the phases of cartilage formation, cartilage hypertrophy and remodeling, bone formation and coupled bone remodeling. TGF-β1 was above controls presurgery before decreasing to baseline shortly after surgery followed by a renewed increase at 6 M to a peak at 2Y during cartilage hypertrophy/remodeling followed by a gradual return to baseline at 10Y during early osteoblastogenesis. TGF-β2 was at control level from presurgery until the phase of cartilage remodeling at 5Y when it increased sharply to a peak at 7Y with a gradual return to baseline at 18Y postsurgery. TGF-β3 remained at control level throughout the study. Conclusion: This study shows that the involvement of BMPs and TGF-βs in endochondral bone repair is a process of stepwise recruitment of individual biomarkers characterized by distinct, yet overlaping, spatiotemporal patterns that extend from the early phase of pre-chondrocyte recruitment until the late phase of coupled bone remodeling.
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27.
  • Chatziagorou, Georgios, et al. (författare)
  • Incidence and demographics of 1751 surgically treated periprosthetic femoral fractures around a primary hip prosthesis.
  • 2019
  • Ingår i: Hip international : the journal of clinical and experimental research on hip pathology and therapy. - : SAGE Publications. - 1724-6067. ; 29:3, s. 282-288
  • Tidskriftsartikel (refereegranskat)abstract
    • Periprosthetic femoral fractures (PPFF), treated surgically, have been recorded in the Swedish Hip Arthroplasty Register (SHAR) since 1979. It is postulated that fractures treated with other methods other than stem revision have a lower registration rate, which may lead to incomplete registry data and thus, inaccurate information. We collected all PPFFs surgically treated in Sweden between 2001 and 2011 with the purpose of studying the annual incidence, demographics and distribution of fracture types with regard to type of fixation.Data was linked between the SHAR and the National Patient Register (NPR) in order to detect even those PPFFs not reported to the SHAR. Fractures were classified according to the Vancouver classification system, based on information collected from the medical charts. This procedure was validated with observer variation analysis compared to fracture classification based on radiographs. In total 1751 first-time PPFFs around primary conventional stems were included.The incidence of PPFF increased from about 1.0 per 1000 primary THRs to 1.4. Vancouver type C fractures (37% of all fractures) were more common than previously reported, and more common in cemented than in uncemented stems. The 3 most common stem designs involved were Exeter polished, Lubinus SPII, and Charnley (66.3% of all stems), partly reflecting their occurrence in the Swedish THR population.The incidence of PPFFs has increased in Sweden during the period 2001 to 2011. The improved reporting of type C fractures, after data-linking, revealed an almost 4 times higher incidence compared to previous register studies in Sweden.
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28.
  • Chatziagorou, Georgios, et al. (författare)
  • Lower reoperation rate with locking plates compared with conventional plates in Vancouver type C periprosthetic femoral fractures: A register study of 639 cases in Sweden
  • 2019
  • Ingår i: Injury. - : Elsevier BV. - 0020-1383 .- 1879-0267. ; 50:12, s. 2292-2300
  • Tidskriftsartikel (refereegranskat)abstract
    • Aim: To investigate demographics and outcomes of Vancouver type C periprosthetic femoral fractures (PPFF) treated with open reduction and internal fixation. Methods: Patient data were obtained from medical charts of cases reported to the Swedish Hip Arthroplasty Register and/or from the National Patient Register. Vancouver type C fractures undergoing surgery between 2001 and 2011, in patients who had received their primary THR between 1979 and 2011, were included. Any further reoperation performed between 2001 and 2013 and related to the PPFF constituted the primary outcome. Results: A total of 632 patients with 639 Vancouver type C fractures were identified. The majority of the patients were women (84%) and they had a fracture distal to a cemented stem (95%). The mean age at the time of fracture was 72 years. Treatment was performed with a locking plate (363 cases), a conventional plate (184 cases), an intramedullary nail (62 cases), or with double plating (30 cases). The overall reoperation rate was 17%, and mortality within one year of the operation was 16%. Locking plates had a significantly lower reoperation rate than conventional plates (p<0.001) and intramedullary nailing (p = 0.005). Interprosthetic femoral fractures did not have a statistically different outcome compared with non-IPFFs. Conclusions: The lowest reoperation rate was observed using locking plates in Vancouver type C fractures when compared with conventional plates or intramedullary nailing. The presence of an ipsilateral knee prosthesis did not influence the outcome of the surgical treatment.
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29.
  • Chatziagorou, Georgios, et al. (författare)
  • Surgical treatment of Vancouver type B periprosthetic femoral fractures PATIENT CHARACTERISTICS AND OUTCOMES OF 1381 FRACTURES TREATED IN SWEDEN BETWEEN 2001 AND 2011
  • 2019
  • Ingår i: Bone & Joint Journal. - 2049-4394. ; 101B:11, s. 1447-1458
  • Tidskriftsartikel (refereegranskat)abstract
    • Aims We investigated patient characteristics and outcomes of Vancouver type B periprosthetic fractures treated with femoral component revision and/or osteosynthesis. Patients and Methods The study utilized data from the Swedish Hip Arthroplasty Register (SHAR) and information from patient records. We included all primary total hip arthroplasties (THAs) performed in Sweden since 1979, and undergoing further surgery due to Vancouver type B periprosthetic femoral fracture between 2001 and 2011. The primary outcome measure was any further reoperation between 2001 and 2013. Cross-referencing with the National Patient Register was performed in two stages, in order to identify all surgical procedures not recorded on the SHAR. Results Out of 1381 Vancouver type B fractures that fulfilled the inclusion criteria, 257 underwent further reoperation by the end of 2013. Interprosthetic and Type B1 fractures had a higher risk for reoperation. For B1 fractures, the rate of reoperation did not differ (p = 0.322) after use of conventional (26%) or locking plate osteosynthesis (19%). No significant differences were observed between cemented, cementless monoblock, and cementless modular revision components for the treatment of type B2 and B3 fractures. Conclusion In this country-specific study, the choice of locking or conventional plates for the treatment of type B1, and cemented or cementless femoral components fixation for B2 and B3 fractures, had no significant influence on risk for reoperation. Interprosthetic fractures adversely affected the outcome of treatment of type B fractures. Differences in the patient characteristics of the compared groups were observed.
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30.
  • Chatziagorou, Georgios, et al. (författare)
  • The design of the cemented stem influences the risk of Vancouver type B fractures, but not of type C: an analysis of 82,837 Lubinus SPII and Exeter Polished stems.
  • 2019
  • Ingår i: Acta orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 90:2, s. 135-142
  • Tidskriftsartikel (refereegranskat)abstract
    • Background and purpose - In total hip replacements, stem design may affect the occurrence of periprosthetic femoral fracture. We studied risk factors for fractures around and distal to the 2 most used cemented femoral stems in Sweden. Patients and methods - This is a register study including all standard primary Lubinus SPII and Exeter Polished stems operated in Sweden between 2001 and 2009. The outcome was any kind of reoperation due to fracture around (Vancouver type B) or distal to the stem (Vancouver type C), with use of age, sex, diagnosis at primary THR, and year of index operation as covariates in a Cox regression analysis. A separate analysis of the primary osteoarthritis patient group was done in order to evaluate eventual influence of the surgical approach (lateral versus posterior) on the risk for Vancouver type B fractures. Results - The Exeter stem had a 10-times (95% CI 7-13) higher risk for type B fractures, compared with the Lubinus, while no statistically significant difference was noticed for type C fractures. The elderly, and patients with hip fracture or idiopathic femoral head necrosis, had a higher risk for both fracture types. Inflammatory arthritis was a risk factor only for type C fractures. Type B fractures were more common in men, and type C in women. A lateral approach was associated with decreased risk for Type B fracture. Interpretation - Stem design influenced the risk for type B, but not for type C fracture. The influence of surgical approach on the risk for periprosthetic femoral fracture should be studied further.
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31.
  • Cnudde, Peter, 1970, et al. (författare)
  • Cement-in-cement revision of the femoral stem: analysis of 1179 first-time revisions in the Swedish Hip Arthroplasty Register.
  • 2017
  • Ingår i: The bone & joint journal. - 2049-4408. ; 99-B:4 Supple B, s. 27-32
  • Tidskriftsartikel (refereegranskat)abstract
    • Compared with primary total hip arthroplasty (THA), revision surgery can be challenging. The cement-in-cement femoral revision technique involves removing a femoral component from a well-fixed femoral cement mantle and cementing a new stem into the original mantle. This technique is widely used and when carried out for the correct indications, is fast, relatively inexpensive and carries a reduced short-term risk for the patient compared with the alternative of removing well-fixed cement. We report the outcomes of this procedure when two commonly used femoral stems are used.We identified 1179 cement-in-cement stem revisions involving an Exeter or a Lubinus stem reported to the Swedish Hip Arthroplasty Register (SHAR) between January 1999 and December 2015. Kaplan-Meier survival analysis was performed.Survivorship is reported up to six years and was better in the Exeter group (91% standard deviation (sd) 2.8% versus 85% sd 5.0%) (p = 0.02). There was, however, no significant difference in the survival of the stem and risk of re-revision for any reason (p = 0.58) and for aseptic loosening (p = 0.97), between revisions in which the Exeter stem (94% sd 2.2%; 98% sd 1.6%) was used compared with those in which the Lubinus stem (95% sd 3.2%; 98% sd2.2%) was used. The database did not allow identification of whether a further revision was indicated for loosening of the acetabular or femoral component or both.The cement-in-cement technique for revision of the femoral component gave promising results using both designs of stem, six years post-operatively. Cite this article: Bone Joint J 2017;99-B(4 Supple B):27-32.
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32.
  • Cnudde, Peter, 1970, et al. (författare)
  • Do Patients Live Longer After THA and Is the Relative Survival Diagnosis-specific?
  • 2018
  • Ingår i: Clinical orthopaedics and related research. - : Ovid Technologies (Wolters Kluwer Health). - 1528-1132 .- 0009-921X. ; 476, s. 1166-1175
  • Tidskriftsartikel (refereegranskat)abstract
    • Hip replacements are successful in restoring mobility, reducing pain, and improving quality of life. However, the association between THA and the potential for increased life expectancy (as expressed by mortality rate) is less clear, and any such association could well be influenced by diagnosis and patient-related, socioeconomic, and surgical factors, which have not been well studied.(1) After controlling for birth year and sex, are Swedish patients who underwent THA likely to survive longer than individuals in the general population? (2) After controlling for relevant patient-related, socioeconomic/demographic factors and surgical factors, does relative survival differ across the various diagnoses for which THAs were performed in Sweden?Data from the Swedish Hip Arthroplasty Register, linked to administrative health databases, were used for this study. We identified 131,808 patients who underwent THA between January 1, 1999, and December 31, 2012. Of these, 21,755 had died by the end of followup. Patient- and surgery-specific data in combination with socioeconomic data were available for analysis. We compared patient survival (relative survival) with age- and sex-matched survival data in the entire Swedish population according to Statistics Sweden. We used multivariable modeling proceeded with a Cox proportional hazards model in transformed time.Patients undergoing elective THA had a slightly improved survival rate compared with the general population for approximately 10 years after surgery. At 1 year after surgery, the survival in patients undergoing THA was 1% better than the expected survival (r = 1.01; 95% confidence interval [CI], 1.01-1.02; p < 0.001); at 5 years, this increased to 3% (r = 1.03; 95% CI, 1.03-1.03; p < 0.001); at 10 years, the difference was 2% (r = 1.02; 95% CI, 1.02-1.03; p < 0.001); and by 12 years, there was no difference between patients undergoing THA and the general population (r = 1.01; 95% CI, 0.99-1.02; p = 0.13). Using the diagnosis of primary osteoarthritis as a reference, hip arthroplasties performed for sequelae of childhood hip diseases had a similar survival rate (hazard ratio [HR], 1.02; 95% CI, 0.88-1.18; p = 0.77). Patients undergoing surgery for osteonecrosis of the femoral head (HR, 1.69; 95% CI, 1.60-1.79; p < 0.001), inflammatory arthritis (HR, 1.49; 95% CI, 1.38-1.61; p < 0.001), and secondary osteoarthritis (HR, 2.46; 95% CI, 2.03-2.99; p < 0.001) all had poorer relative survival. Comorbidities and the Elixhauser comorbidity index had a negative association with relative survival. Level of achieved education (middle level of education: HR, 0.90, 95% CI, 0.87-0.93, p < 0.001; high level: 0.76, 95% CI, 0.73-0.80, p < 0.001) and marital status (single status: HR, 1.33; 95% CI, 1.28-1.38; p < 0.001) were also negatively associated with survival.Whereas it has been known that in most patients, THA improves quality of life, this study demonstrates that it also is associated with a slightly increased life expectancy that lasts for approximately 10 years after surgery, especially among patients whose diagnosis was primary osteoarthritis. This adds further proof of a health-economic value for this surgical intervention. The reasons for the increase in relative survival are unknown but are probably multifactorial.Level III, therapeutic study.
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33.
  • Cnudde, Peter, 1970, et al. (författare)
  • Linking Swedish health data registers to establish a research database and a shared decision-making tool in hip replacement
  • 2016
  • Ingår i: BMC Musculoskeletal Disorders. - : Springer Science and Business Media LLC. - 1471-2474. ; 17:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Sweden offers a unique opportunity to researchers to construct comprehensive databases that encompass a wide variety of healthcare related data. Statistics Sweden and the National Board of Health and Welfare collect individual level data for all Swedish residents that ranges from medical diagnoses to socioeconomic information. In addition to the information collected by governmental agencies the medical profession has initiated nationwide Quality Registers that collect data on specific diagnoses and interventions. The Quality Registers analyze activity within healthcare institutions, with the aims of improving clinical care and fostering clinical research. Main body: The Swedish Hip Arthroplasty Register (SHAR) has been collecting data since 1979. Joint replacement in general and hip replacement in particular is considered a success story with low mortality and complication rate. It is credited to the pioneering work of the SHAR that the revision rate following hip replacement surgery in Sweden is amongst the lowest in the world. This has been accomplished by the diligent follow-up of patients with feedback of outcomes to the providers of the healthcare along with post market surveillance of individual implant performance. During its existence SHAR has experienced a constant organic growth. One major development was the introduction of the Patient Reported Outcome Measures program, giving a voice to the patients in healthcare performance evaluation. The next aim for SHAR is to integrate patients' wishes and expectations with the surgeons' expertise in the form of a Shared Decision-Making (SDM) instrument. The first step in building such an instrument is to assemble the necessary data. This involves linking the SHARs database with the two aforementioned governmental agencies. The linkage is done by the 10-digit personal identity number assigned at birth (or immigration) for every Swedish resident. The anonymized data is stored on encrypted serves and can only be accessed after double identification. Conclusion: This data will serve as starting point for several research projects and clinical improvement work.
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34.
  • Cnudde, Peter, 1970, et al. (författare)
  • Risk of further surgery on the same or opposite side and mortality after primary total hip arthroplasty: A multi-state analysis of 133,654 patients from the Swedish Hip Arthroplasty Register
  • 2018
  • Ingår i: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3674 .- 1745-3682. ; 89:4, s. 386-393
  • Tidskriftsartikel (refereegranskat)abstract
    • Background and purpose - The hip-related timeline of patients following a total hip arthroplasty (THA) can vary. Ideally patients will live their life without need for further surgery; however, some will undergo replacement on the contralateral hip and/or reoperations. We analyzed the probability of mortality and further hip-related surgery on the same or contralateral hip. Patients and methods - We performed a multi-state survival analysis on a prospectively followed cohort of 133,654 Swedish patients undergoing an elective THA between 1999 and 2012. The study used longitudinally collected information from the Swedish Hip Arthroplasty Register and administrative databases. The analysis considered the patients' sex, age, prosthesis type, surgical approach, diagnosis, comorbidities, education, and civil status. Results - During the study period patients were twice as likely to have their contralateral hip replaced than to die. However, with passing time, probabilities converged and for a patient who only had 1 non-revised THA at 10 years, there was an equal chance of receiving a second THA and dying (24%). It was 8 times more likely that the second hip would become operated with a primary THA than that the first hip would be revised. Multivariable regression analysis reinforced the influence of age at operation, sex, diagnosis, comorbidity, and socioeconomic status influencing state transition. Interpretation - Multi-state analysis can provide a comprehensive model of further states and transition probabilities after an elective THA. Information regarding the lifetime risk for bilateral surgery, revision, and death can be of value when discussing the future possible outcomes with patients, in healthcare planning, and for the healthcare, economy.
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35.
  • Cnudde, Peter, 1970, et al. (författare)
  • Trends in hip replacements between 1999 and 2012 in Sweden.
  • 2018
  • Ingår i: Journal of orthopaedic research. - : Wiley. - 0736-0266 .- 1554-527X. ; 36:1, s. 432-442
  • Tidskriftsartikel (refereegranskat)abstract
    • National Registers document changes in the circumstance, practice, and outcome of surgery with the passage of time. In the context of total hip replacement (THR), registers can help elucidate the relevant factors that affect the clinical outcome. We evaluated the evolution of factors related to patient, surgical procedure, socio-economy, and various outcome parameters after merging databases of the Swedish Hip Arthroplasty Register, Statistics Sweden and the National Board of Health and Welfare. Data on 193,253 THRs (164,113 patients) operated between 1999 and 2012 were merged. We studied the evolution of surgical volume, patient demographics, socio-economic factors, surgical factors, length-of-stay, mortality rate, adverse events, re-operation and revision rates, and Patient Reported Outcome Measures (PROMs). Throughout this time period the majority of patients were operated on with a diagnosis of primary osteoarthritis. Comorbidity indices increased each year observed. The share of all-cemented implants has dropped from 92% to 68%. More than 88% of the bearings were metal-on-polyethylene. Length-of-stay decreased by 50%. There was a reduction in 30- and 90-day mortality. Re-operation and revision rates at 2 years are decreasing. The post-operative PROMs improved despite the observation of worse pre-operative pain scores getting over time. The demographics of patients receiving a THR, their comorbidities, and their primary diagnosis are changing. Notwithstanding these changes, outcomes like mortality, re-operations, revisions, and PROMs have improved. The practice of hip arthroplasty has evolved, even in a country such as Sweden that is considered to be conservative with regard taking on new surgical practices. © 2017 The Authors. Journal of Orthopaedic Research Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res.
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36.
  • Cnudde, Peter, 1970, et al. (författare)
  • Trends in the patient demographics, socio-economic characteristics, surgical factors and outcomes between 1999 and 2012
  • 2017
  • Ingår i: Orthopaedic Proceedings. 99-B (SUPP 12). - : British Editorial Society of Bone & Joint Surgery. - 1358-992X .- 2049-4416.
  • Konferensbidrag (refereegranskat)abstract
    • Prospectively collected data is an important source of information subjected to change over time. What surgeons were doing in 1999 might not be the case anymore in 2016 and this change in time also applies to a number of factors related to the performance and outcome of total hip replacement. We evaluated the evolution of factors related to the patient, the surgical procedure, socio-economy and various outcome parameters after merging the databases of the Swedish Hip Arthroplasty Register, Statistics Sweden and the National Board of Health and Welfare. Data on 193,253 THRs (164,113 patients) operated between 1999 and 2012 were merged with databases including general information about the Swedish population and about hospital care. We studied the evolution of surgical volume, patient demographics, socio-economic factors, surgical factors, length of stay, mortality rate, adverse events, re-operation and revision rates and PROMs. Most patients were operated because of primary osteoarthritis and this share increased further during the period at the expense of decreasing number of patients with inflammatory OA and hip fracture. Comorbidity and ASA scores increased for each year. The share of all cemented implants has dropped from 92% to 68% with a corresponding increase of all uncemented from 2% to 16%. Length of stay decreased with about 50 percent to 4.5 days in 2012. The 30- and 90-day mortality rate dropped to 0.4% and 0.7%. Re-operation and revision rates at 2 years were lower in the more recent years. The postoperative PROMs are improving despite the preoperative pain scores getting worse. Even in Sweden, always been considered as a very conservative country with regards to hip replacement surgery, the demographics of the patients, the comorbidities and the primary diagnosis for surgery are changing. Despite these changes the outcomes like mortality, re-operations, revisions and PROMs are improving.
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37.
  • Dale, Håvard, et al. (författare)
  • Increasing risk of prosthetic joint infection after total hip arthroplasty.
  • 2012
  • Ingår i: Acta orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 83:5, s. 449-58
  • Tidskriftsartikel (refereegranskat)abstract
    • Background and purpose The risk of revision due to infection after primary total hip arthroplasty (THA) has been reported to be increasing in Norway. We investigated whether this increase is a common feature in the Nordic countries (Denmark, Finland, Norway, and Sweden). Materials and methods The study was based on the Nordic Arthroplasty Register Association (NARA) dataset. 432,168 primary THAs from 1995 to 2009 were included (Denmark: 83,853, Finland 78,106, Norway 88,455, and Sweden 181,754). Adjusted survival analyses were performed using Cox regression models with revision due to infection as the endpoint. The effect of risk factors such as the year of surgery, age, sex, diagnosis, type of prosthesis, and fixation were assessed. Results 2,778 (0.6%) of the primary THAs were revised due to infection. Compared to the period 1995-1999, the relative risk (with 95% CI) of revision due to infection was 1.1 (1.0-1.2) in 2000-2004 and 1.6 (1.4-1.7) in 2005-2009. Adjusted cumulative 5-year revision rates due to infection were 0.46% (0.42-0.50) in 1995-1999, 0.54% (0.50-0.58) in 2000-2004, and 0.71% (0.66-0.76) in 2005-2009. The entire increase in risk of revision due to infection was within 1 year of primary surgery, and most notably in the first 3 months. The risk of revision due to infection increased in all 4 countries. Risk factors for revision due to infection were male sex, hybrid fixation, cement without antibiotics, and THA performed due to inflammatory disease, hip fracture, or femoral head necrosis. None of these risk factors increased in incidence during the study period. Interpretation We found increased relative risk of revision and increased cumulative 5-year revision rates due to infection after primary THA during the period 1995-2009. No change in risk factors in the NARA dataset could explain this increase. We believe that there has been an actual increase in the incidence of prosthetic joint infections after THA.
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38.
  • Dale, H., et al. (författare)
  • Increasing risk of revision due to infection after primary total hip arthroplasty: results from the Nordic Arthro- plasty Register Association
  • 2023
  • Ingår i: Acta orthopaedica. - : Medical Journals Sweden. - 1745-3674 .- 1745-3682. ; 94, s. 307-315
  • Tidskriftsartikel (refereegranskat)abstract
    • Background and purpose - The incidence of peripros-thetic joint infection after total hip arthroplasty (THA) may be increasing. We performed time-trend analyses of risk, rates, and timing of revision due to infection after primary THAs in the Nordic countries from the period 2004-2018. Patients and methods - 569,463 primary THAs reported to the Nordic Arthroplasty Register Association from 2004 to 2018 were studied. Absolute risk estimates were calculated by Kaplan-Meier and cumulative incidence function methods, whereas adjusted hazard ratios (aHR) were assessed by Cox regression with the first revision due to infection after primary THA as primary endpoint. In addi-tion, we explored changes in the time span from primary THA to revision due to infection. Results - 5,653 (1.0%) primary THAs were revised due to infection during a median follow-up time of 5.4 (IQR 2.5-8.9) years after surgery. Compared with the period 2004-2008, the aHRs for revision were 1.4 (95% confidence interval [CI] 1.3-1.5) for 2009-2013, and 1.9 (CI 1.7-2.0) for 2014-2018. The absolute 5-year rates of revision due to infection were 0.7% (CI 0.7-0.7), 1.0% (CI 0.9-1.0), and 1.2% (CI 1.2-1.3) for the 3 time periods respectively. We found changes in the time span from primary THA to revi-sion due to infection. Compared with 2004-2008, the aHR for revision within 30 days after THA was 2.5 (CI 2.1-2.9) for 2009-2013, and 3.4 (CI 3.0-3.9) for 2013-2018. The aHR for revision within 31-90 days after THA was 1.5 (CI 1.3-1.9) for 2009-2013, and 2.5 (CI 2.1-3.0) for 2013-2018, compared with 2004-2008.Conclusion - The risk of revision due to infection after primary THA almost doubled, both in absolute cumulative incidence and in relative risk, throughout the period 2004- 2018. This increase was mainly due to an increased risk of revision within 90 days of THA. This may reflect a "true" increase (i.e., frailer patients or more use of uncemented implants) and/or an "apparent" increase (i.e., improved diagnostics, changed revision strategy, or completeness of reporting) in incidence of periprosthetic joint infection. It is not possible to disclose such changes in the present study, and this warrants further research.
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39.
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40.
  • Digas, Georgios, 1963, et al. (författare)
  • Addition of fluoride to acrylic bone cement does not improve fixation of a total hip arthroplasty stem
  • 2006
  • Ingår i: Clin Orthop Relat Res. - 0009-921X. ; 448, s. 58-66
  • Tidskriftsartikel (refereegranskat)abstract
    • Improved fixation to bone is vital for improving the long term success of cemented implants. Addition of fluoride to acrylic bone cement may be one way to improve the quality of the bone cement interface and thereby reduce the risk of loosening. Ninety patients (97 hips) with a median age of 70 years (range, 31-81 years) scheduled for total hip arthroplasty were randomized to receive a stem fixed with fluoride-containing acrylic bone cement or conventional acrylic bone cement. Fixation and bone remodeling around the femoral component was studied with radiostereometry and dual-energy xray absorptiometry up to 5 years after the operation in 73 patients (77 hips). Radiostereometric evaluation at 5 years revealed no differences in stem migration (subsidence/lift-off) or rotations. The stem subsidence inside the mantle was similar in the two groups. At 5 years the study group had lost more bone mineral in Gruen regions 5 and 7 than the controls. The Harris hip and pain score did not differ. Use of fluoride containing bone cement did not improve the stem fixation compared with a conventional cement used up to 5 years, but resulted in more pronounced loss of bone mineral density in the medial cortex. LEVEL OF EVIDENCE: Therapeutic Level I. See Guidelines for Authors for a complete description of levels of evidence.
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41.
  • Digas, Georgios, 1963, et al. (författare)
  • Bioactive cement or ceramic/porous coating vs. conventional cement to obtain early stability of the acetabular cup. Randomised study of 96 hips followed with radiostereometry
  • 2004
  • Ingår i: J Orthop Res. - : Wiley. - 0736-0266. ; 22:5, s. 1035-43
  • Tidskriftsartikel (refereegranskat)abstract
    • Ninety patients (96 hips) scheduled for THA were stratified to fixation of the acetabular component in three main groups of about equal size. Fluoride cement, porous coated press-fit cup with ceramic coating or Palacos cum Gentamicin cement were used. All patients received Spectron EF stem. The migration of the cups and the femoral head penetration into the socket were measured with radiostereometric analysis. At 2 years the choice of fixation did not influence the migration or rotation of the cup. Patients with compromised bone quality showed increased three-dimensional (3D or total) migration. Proximal and 3D penetration rates were increased in cemented compared with the uncemented cups (p<0.001), which probably not could be related to the choice of fixation. Appearance of radiolucent lines was almost equal in the two cemented groups. Uncemented cups had less radiolucent lines at 2 years. Fluoride containing cement or uncemented fixation did not improve the early postoperative stability of the socket.
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42.
  • Digas, Georgios, 1963, et al. (författare)
  • Different loss of BMD using uncemented press-fit and whole polyethylene cups fixed with cement: repeated DXA studies in 96 hips randomized to 3 types of fixation
  • 2006
  • Ingår i: Acta Orthop. - : Medical Journals Sweden AB. - 1745-3674. ; 77:2, s. 218-26
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: In cemented THA, aseptic loosening of the cup is more common than loosening of the stem, while periprosthetic osteolysis of the socket resulting in difficult reconstruction problems has emerged as the most significant problem with cementless cup fixation. PATIENTS AND METHODS: 90 patients (96 hips) scheduled for THA were stratified in three groups according to the method of fixation of the acetabular component: acrylic bone cement with fluoride (Cemex-F), porous-coated press-fit cup with ceramic coating (Trilogy, uncemented) and acrylic cement with gentamicin (Palacos). All patients received the Spectron EF stem. Acetabular bone mineral density was measured with dual-energy X-ray absorptiometry (DXA) 1 week postoperatively, and after 12 and 24 months. The periprosthetic BMD was evaluated in 5 ROIs positioned around the acetabular component. RESULTS: In the uncemented sockets, the BMD had decreased proximally and medially to the cup after 2 years. The difference was significant in the proximal region as compared to the control group (Palacos). No difference was noted between the 2 groups with cemented components after 2 years. Stepwise linear regression analysis showed that loss of periprosthetic BMD in the proximal high-pressure region after 2 years increased with higher postoperative BMD and when the uncemented design had been used. INTERPRETATION: Contrary to previous studies of cemented stems, the use of fluoride cement did not influence the periprosthetic BMD 2 years after the examination. Increased loss of BMD with use of uncemented press-fit cups in the region in which osteolytic lesions are commonly found suggests that stress shielding may initiate the development of this complication. Longer follow-up will, however, be necessary to substantiate this hypothesis.
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43.
  • Digas, Georgios, 1963, et al. (författare)
  • Five-year DEXA study of 88 hips with cemented femoral stem
  • 2009
  • Ingår i: International Orthopaedics. - : Springer Science and Business Media LLC. - 0341-2695 .- 1432-5195. ; 33:6, s. 1495-500
  • Tidskriftsartikel (refereegranskat)abstract
    • We performed repeated dual-energy X-ray absorptiometry (DEXA) measurements over five years in a homogeneous patient population to study the effect of a cemented stem on proximal femoral bone remodelling. Data from 88 patients (88 hips) implanted with total hip arthroplasty (THA) prostheses were extracted from three randomised studies. Femoral bone mineral density (BMD) was measured using a Lunar DPX-IQ densitometer for five years postoperatively. At one year the BMD changes had decreased between -2.0% [region of interest (ROI) 1] and -11.5% (ROI 7). During the follow-up period the BMD initially increased during the second year and thereafter decreased again in ROIs 5, 6 and 7. The loss of BMD at five years was more pronounced in region 7 (12.9%) and decreased with increasing age, total hip replacement (THR) on the right side and decreasing weight of the patient. We found that after the initial phase of early bone loss a period of recovery follows. Thereafter the BMD decreases again, which probably reflects the normal ageing of bone after uncomplicated cemented THA.
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44.
  • Digas, Georgios, 1963, et al. (författare)
  • Fluoride-containing acrylic bone cement in total hip arthroplasty. Randomized evaluation of 97 stems using radiostereometry and dual-energy x-ray absorptiometry
  • 2005
  • Ingår i: J Arthroplasty. - : Elsevier BV. - 0883-5403. ; 20:6, s. 784-92
  • Tidskriftsartikel (refereegranskat)abstract
    • Ninety patients (97 hips) scheduled for total hip arthroplasty were stratified to fixation of the femoral component using fluoride-containing cement or Palacos with gentamicin. Whole polyethylene Reflection and press-fit Trilogy cups were used. All patients received Spectron EF stem. The micromotions of the stem were measured with radiostereometric analysis and the periprosthetic bone mineral density with automatic and manual dual-energy x-ray absorptiometry (DEXA) analysis. At 2 years, the choice of cement did not influence the subsidence or rotations of the stem. The DEXA analysis revealed more loss of periprosthetic bone mineral density in fluoride cement group. We speculate that forming of fluorapatite crystals, toxic effects of the fluoride, or lower radiopacity of the fluoride cement might explain this finding. According to our study with 2-year of follow-up, there is no obvious advantage of addition of fluoride to acrylic bone cement when used to fixate the femoral component in total hip arthroplasty.
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45.
  • Digas, Georgios, et al. (författare)
  • Increase in early polyethylene wear after sterilization with ethylene oxide : radiostereometric analyses of 201 total hips.
  • 2003
  • Ingår i: Acta Orthopaedica Scandinavica. - : Medical Journals Sweden AB. - 0001-6470. ; 74:5, s. 531-541
  • Tidskriftsartikel (refereegranskat)abstract
    • We evaluated polyethylene wear by measuring femoral head penetration in 201 THA (median age 62 (31-81) years, 117 women) extracted from 5 randomized studies aimed to assess various fixation principles. There were 30 cemented all-polyethylene Lubinus cups sterilized by gamma irradiation in a reduced oxygen environment, 65 porous-coated Trilogy cups with liners gamma-sterilized in inert gas. Moreover, 37 cemented cups were sterilized with ethylene oxide (Reflection all-poly) and 69 porous-coated cups had liners sterilized in ethylene oxide (Reflection). 28 mm femoral heads were used in all cups. The patients were followed with repeated radiostereometric measurements (RSA) up to 2 years. The activity level of the patients was evaluated by a questionnaire. After 2 years, cups with polyethylene sterilized in EtO had almost twice the proximal and 3D penetration rates, as compared with gamma-sterilized polyethylene. The penetration did not differ between the gamma-irradiated designs. Using stepwise linear regression analysis, we found that the type of sterilization, age and weight were the most important predictors and that they determined the direction of the proximal penetration rate. Activity score, male gender and proximal migration of the cup had little effect. The accelerated wear observed with the EtO-sterilized polyethylene causes concerns about long-term problems and especially in younger patients.
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46.
  • Digas, Georgios, 1963, et al. (författare)
  • Inducible Displacements of the Cup and the Femoral Head During Active Range of Motion: Dynamic RSA Studies of Cemented Total Hip Replacements
  • 2013
  • Ingår i: Journal of Orthopaedic Research. - : Wiley. - 0736-0266. ; 31:11, s. 1686-1693
  • Tidskriftsartikel (refereegranskat)abstract
    • We evaluated changes in position of the femoral head relative to the cup and of the cup relative to the pelvis in total hip replacement patients during hip motion 2 years postoperatively. Two patient groups with nine patients in each group were studied. Hip motions, translations of the femoral head center, and cup displacements were recorded with dynamic radiostereometric examination (RSA, 2exposures/s) during abduction in Group 1 and with use of static RSA exposures at increasing flexion of the hip in Group 2. Conventional radiographic examinations were used to evaluate any radiolucent lines around the cups at 2 years. During active abduction the femoral head center moved medially (median 0.04mm) and the cup tilted anteriorly (median 0.09mm). Increments in radiolucent lines at 2 years correlated to medial femoral head penetration, posterior tilt, and retroversion of the cup at 20 degrees of abduction. The extension of radiolucent lines at 2 years showed a positive correlation with proximal inducible displacement of the cup and posterior translation of the femoral head center at maximum hip flexion. Our observations may be of value in understanding the pathogenesis of the loosening process and may be used to facilitate the development of prosthetic designs that optimize hip kinematics. (c) 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1686-1693, 2013
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47.
  • Digas, Georgios, 1963, et al. (författare)
  • The Otto Aufranc Award. Highly cross-linked polyethylene in total hip arthroplasty: randomized evaluation of penetration rate in cemented and uncemented sockets using radiostereometric analysis
  • 2004
  • Ingår i: Clin Orthop Relat Res. - 0009-921X. ; :429, s. 6-16
  • Tidskriftsartikel (refereegranskat)abstract
    • The annual wear rate in polyethylene articulations should be 0.1 mm or less to avoid future osteolysis. Highly cross-linked polyethylene shows an 80 to 90% wear reduction in hip simulator testing, but the clinical documentation of this new polyethylene is still inadequate. We evaluated the highly cross-linked polyethylene in two prospective randomized clinical studies. Thirty-two patients (12 men, 20 women; 64 hips) with a median age of 48 years (range, 29-70 years) with bilateral primary or secondary arthrosis of the hip had hybrid total hip arthroplasty with liners made of highly cross-linked polyethylene on one side and conventional polyethylene on the other. Twenty-seven patients in this study have passed 2 years followup. A further group, comprised of 60 patients (61 hips) with a median age of 55 years (range, 35-70 years), was randomized to receive either highly cross-linked polyethylene or conventional cemented all-polyethylene of the same design. Forty-nine of these 60 patients have been observed for 3 years. In both studies all patients received Spectron stems with 28-mm Co-Cr heads. Radiostereometric examinations with the patient supine or standing were done at regular intervals. Wear was measured in the supine position from the first postoperative week, whereas standing examinations were initiated 3 months after the operation. The penetration rate almost was identical in the study and control groups at 6 months after the operation. Thereafter, the penetration rate leveled out in the two groups with highly cross-linked polyethylene. At 2 years the highly cross-linked polyethylene liner showed 62% lower proximal penetration and 31% lower total (three-dimensional) penetration when the patients were examined in supine position. The highly crosslinked all-polyethylene cemented cups showed lower proximal penetration in both positions. The better wear performance of highly cross-linked polyethylene could increase the implant longevity. Longer followup is needed to evaluate if this new material is associated with less occurrence of osteolysis.
  •  
48.
  • Edensor, Tim, et al. (författare)
  • Rhythmanalysing the urban runner : Pildammsparken, Malmö
  • 2018
  • Ingår i: Applied Mobilities. - : Informa UK Limited. - 2380-0135 .- 2380-0127. ; 3:2, s. 97-114
  • Tidskriftsartikel (refereegranskat)abstract
    • In this article we discuss the development of urbanized running culture by exploring how the embodied rhythms of running interact with other urban rhythms in a park. The analysis focuses on the timings, sensations and materialities produced through running, and how the rhythms of running intersect with the materialities and rhythms of others. The investigation draws on interviews, observations and a running diary undertaken at Pildammsparken in central Malmö. Our research shows that while the runner, in endeavouring to align with the rhythms of others, may becoming a more disciplined figure, running in the park is more concerned with practising a sharing of space than moving on auto-pilot. Consequently, running is largely a mobile rhythmic practice that negotiates and adapts to co-produce eurhythmic choreographies in this particular urban location.
  •  
49.
  • Eneqvist, Ted, 1982, et al. (författare)
  • How do EQ-5D-3L and EQ-5D-5L compare in a Swedish total hip replacement population?
  • 2020
  • Ingår i: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3674 .- 1745-3682. ; 91:3, s. 272-278
  • Tidskriftsartikel (refereegranskat)abstract
    • Background and purpose - To better detect small changes in postoperative outcome following total hip replacement (THR), the Swedish Hip Arthroplasty Register (SHAR) has decided to change from the EQ-5D-3L (3L) to the EQ-5D-5L (5L). To enable comparison of results obtained with use of the 2 versions of EQ-5D, transferal of results between the questionnaires used is necessary. We assessed the measurement properties of the EQ-5D-5L compared with the EQ-5D-3L, preoperatively and 1-year postoperatively in a Swedish THR population. Patients and methods - Patients eligible for elective THR during 2015 in Western Sweden were invited to the study. With a 2-week separation, the 3L and 5L questionnaires were administered to patients before and 1 year after surgery. Comparing the 2 versions of the EQ-5D, we investigated redistribution of responses, ceiling and floor effects, EQ VAS correlations (Spearman's rank correlation coefficient, r(s)), and EQ VAS scores for different severity levels by dimension (univariable ordinary least square regression). Results - The additional severity levels of the 5L version were frequently used on both measurement occasions (preoperative mobility 5%, self-care 17%, usual activities 20%, pain 5% and anxiety 3%, postoperative mobility 6%, self-care 5%, usual activities 8%, pain 9%, and anxiety 5%). Ceiling effects of the 3L version diminished overall by 7% using the 5L version. The correlations between the 2 EQ VAS scores obtained with the 3L and 5L instruments were strong both pre- (r(s) = 0.71) and postoperatively (r(s) = 0.87). Estimated EQ VAS scores for different levels of severity were consistent for all dimensions except for the mobility dimension of the preoperative 5L version and the anxiety dimension in the postoperative 5L version. Interpretation - Our findings support that the 5L has a higher resolution than the 3L version regarding description of health-related quality of life in patients undergoing THR in Sweden. The EQ VAS scores for different levels of severity agree well between the EQ-5D versions. This could potentially be used to develop a crosswalk value set for transforming 3L to 5L responses in this patient group.
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50.
  • Engesæter, Lars B, et al. (författare)
  • Low revision rate after total hip arthroplasty in patients with pediatric hip diseases.
  • 2012
  • Ingår i: Acta orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 83:5, s. 436-41
  • Tidskriftsartikel (refereegranskat)abstract
    • Background The results of primary total hip arthroplasties (THAs) after pediatric hip diseases such as developmental dysplasia of the hip (DDH), slipped capital femoral epiphysis (SCFE), or Perthes' disease have been reported to be inferior to the results after primary osteoarthritis of the hip (OA). Materials and methods We compared the survival of primary THAs performed during the period 1995-2009 due to previous DDH, SCFE, Perthes' disease, or primary OA, using merged individual-based data from the Danish, Norwegian, and Swedish arthroplasty registers, called the Nordic Arthroplasty Register Association (NARA). Cox multiple regression, with adjustment for age, sex, and type of fixation of the prosthesis was used to calculate the survival of the prostheses and the relative revision risks. Results 370,630 primary THAs were reported to these national registers for 1995-2009. Of these, 14,403 THAs (3.9%) were operated due to pediatric hip diseases (3.1% for Denmark, 8.8% for Norway, and 1.9% for Sweden) and 288,435 THAs (77.8%) were operated due to OA. Unadjusted 10-year Kaplan-Meier survival of THAs after pediatric hip diseases (94.7% survival) was inferior to that after OA (96.6% survival). Consequently, an increased risk of revision for hips with a previous pediatric hip disease was seen (risk ratio (RR) 1.4, 95% CI: 1.3-1.5). However, after adjustment for differences in sex and age of the patients, and in fixation of the prostheses, no difference in survival was found (93.6% after pediatric hip diseases and 93.8% after OA) (RR 1.0, CI: 1.0-1.1). Nevertheless, during the first 6 postoperative months more revisions were reported for THAs secondary to pediatric hip diseases (RR 1.2, CI: 1.0-1.5), mainly due to there being more revisions for dislocations (RR 1.8, CI: 1.4-2.3). Comparison between the different diagnosis groups showed that the overall risk of revision after DDH was higher than after OA (RR 1.1, CI: 1.0-1.2), whereas the combined group Perthes' disease/SCFE did not have a significantly different risk of revision to that of OA (RR 0.9, CI: 0.7-1.0), but had a lower risk than after DDH (RR 0.8, CI: 0.7-1.0). Interpretation After adjustment for differences in age, sex, and type of fixation of the prosthesis, no difference in risk of revision was found for primary THAs performed due to pediatric hip diseases and those performed due to primary OA.
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