| 1. |
- Angelomenos, Vasileios, et al.
(author)
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A prospective randomized study of Refobacin Bone Cement R versus Palacos R plus G FEMORAL COMPONENT MIGRATION AT TWO YEARS POSTOPERATIVELY
- 2024
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In: BONE & JOINT JOURNAL. - 2049-4394. ; 106B:5, s. 435-441
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Journal article (peer-reviewed)abstract
- Aims Refobacin Bone Cement R and Palacos R + G bone cement were introduced to replace the original cement Refobacin Palacos R in 2005. Both cements were assumed to behave in a biomechanically similar fashion to the original cement. The primary aim of this study was to compare the migration of a polished triple- tapered femoral stem fixed with either Refobacin Bone Cement R or Palacos R + G bone cement. Repeated radiostereometric analysis was used to measure migration of the femoral head centre. The secondary aims were evaluation of cement mantle, stem positioning, and patient- reported outcome measures. Methods Overall, 75 patients were included in the study and 71 were available at two years postoperatively. Prior to surgery, they were randomized to one of the three combinations studied: Palacos cement with use of the Optivac mixing system, Refobacin with use of the Optivac system, and Refobacin with use of the Optipac system. Cemented MS30 stems and cemented Exceed acetabular components were used in all hips. Postoperative radiographs were used to assess the quality of the cement mantle according to Barrack et al, and the position and migration of the femoral stem. Harris Hip Score, Oxford Hip Score, Forgotten Joint Score, and University of California, Los Angeles Activity Scale were collected. Results Median distal migration (y - axis) at two years for the Refobacin- Optivac system was -0.79 mm (- 2.01 to -0.09), for the Refobacin- Optipac system was -0.75 mm (- 2.16 to 0.20), and for the Palacos- Optivac system was -1.01 mm (- 4.31 to -0.29). No statistically significant differences were found between the groups. Secondary outcomes did not differ statistically between the groups at the two- year follow- up. Conclusion At two years, we found no significant differences in distal migration or clinical outcomes between the three groups. Our data indicate that Refobacin Bone Cement R and Palacos R + G are comparable in terms of stable fixation and early clinical outcomes.
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| 2. |
- Angelomenos, Vasileios, et al.
(author)
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Precision of low-dose CT-based micromotion analysis technique for the assessment of early acetabular cup migration compared with gold standard RSA: a prospective study of 30 patients up to 1 year
- 2022
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In: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3674 .- 1745-3682. ; 93, s. 459-465
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Journal article (peer-reviewed)abstract
- Background and purpose - Computed tomography micromotion analysis (CTMA) can be used to determine implant micro-movements using low-dose CT scans. By using CTMA, a non-invasive measurement of joint implant movement is enabled. We evaluated the precision of CTMA in measuring early cup migration. Standard marker-based radiostereometric analysis (RSA) was used as reference. We hypothesised that CTMA can be used as an alternative to RSA in assessing implant micromotions. Patients and methods - We included 30 patients undergoing total hip arthroplasty (THA). Acetabular cup migration at 1 year was measured with RSA and CTMA. To determine the precision of both methods, 20 double examinations (postoperatively) with repositioning of the patients were performed. The precision was calculated from zero by assuming that there was no motion of the prosthesis between the 2 examinations. Results - The precision of RSA ranged from 0.06 to 0.15 mm for translations and 0.21 degrees to 0.63 degrees for rotations. Corresponding values for CTMA were 0.06 to 0.13 mm and 0.23 degrees to 0.35 degrees. A good level of agreement was found between the methods regarding cup migration and rotation at 1 year. Interpretation - The precision of CTMA in measuring acetabular cup migration and rotation is comparable to marker-based RSA. CTMA could possibly thus be used as an alternative method to detect early implant migration.
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| 3. |
- Galea, V. P., et al.
(author)
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Evaluation of in vivo wear of vitamin E-diffused highly crosslinked polyethylene at five years
- 2018
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In: Bone and Joint Journal. - 2049-4394. ; 100B100-B:12, s. 1592-1599
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Journal article (peer-reviewed)abstract
- Aims The primary aim of this study was to compare the wear properties of vitamin E-diffused, highly crosslinked polyethylene (VEPE) and one formulation of moderately crosslinked and mechanically annealed ultra-high molecular weight polyethylene (ModXLPE) in patients five years after primary total hip arthroplasty (THA). The secondary aim was to assess the clinical results of patients treated with VEPE by evaluating patient-reported outcome measures (PROMs), radiological evidence of fixation, and the incidence of mechanical failure. Patients and Methods A total of 208 patients (221 THAs) from four international centres were recruited into a prospective study involving radiostereometric analysis (RSA) and the assessment of clinical outcomes. A total of 193 hips (87%) were reviewed at the five-year follow-up. Of these, 136 (70%) received VEPE (vs ModXLPE) liners and 68 (35%) received ceramic (vs metal) femoral heads. PROMs and radiographs were collected preoperatively and at one, two, and five years postoperatively. In addition, RSA images were collected to measure PE wear postoperatively and at one, two, and five years after surgery. Results We observed similar bedding in one year postoperatively and wear two years postoperatively between the two types of liner. However, there was significantly more penetration of the femoral head in the ModXLPE cohort compared with the VEPE cohort five years postoperatively (p < 0.001). The only variables independently predictive of increased wear were ModXLPE (vs VEPE) liner type (β = 0.22, p = 0.010) and metal (vs ceramic) femoral head (β = 0.21, p = 0.013). There was no association between increased wear and the development of radiolucency (p = 0.866) or PROMs. No patient had evidence of osteolysis. Conclusion Five years postoperatively, patients with VEPE (vs ModXLPE) and ceramic (vs metal) femoral heads had decreased wear. The rates of wear for both liners were very low and have not led to any osteolysis or implant failure due to aseptic loosening. ©2018 The British Editorial Society of Bone & Joint Surgery.
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| 4. |
- Johanson, Per-Erik, et al.
(author)
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Early Subsidence Predicts Failure of a Cemented Femoral Stem With Minor Design Changes
- 2016
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In: Clinical Orthopaedics and Related Research. - : Ovid Technologies (Wolters Kluwer Health). - 0009-921X. ; 474:10, s. 2221-2229
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Journal article (peer-reviewed)abstract
- Radiostereometry (RSA) measurements of early micromotion can predict later failure in hip and knee prostheses. In hip implants, RSA has been particularly helpful in the evaluation of composite-beam stem designs. The Spectron EF Primary stem (Smith & Nephew, London, UK) has shown inferior performance compared with its predecessors in both clinical studies and registry reports. Early RSA studies have shown somewhat greater subsidence for the Spectron EF Primary stem compared with the earlier Spectron EF, but still within boundaries considered to be safe. Our primary research question was whether stem subsidence and rotation for this stem design measured with RSA at 2 years can predict later stem failure. A secondary question was whether high femoral stem offset and small stem sizes, both features specific to the Spectron EF Primary stem compared with its predecessors, are associated with stem failure rate. Two hundred forty-seven hips (209 patients with median age 63 years [range, 29-80 years], 65% female, and 77% primary osteoarthritis) with a valid RSA examination at 2 years were selected from four different RSA studies (totaling 279 hips in 236 patients) in our department. The studies were primarily aimed at evaluating cup fixation, bone cement, and polyethylene types. All study patients received a cemented Spectron EF Primary stem. The selected hips had complete followup until stem failure, death, or the end of the followup period. Stem failure was defined as revision of a loose femoral stem or radiological failure with significant osteolysis in Gruen zones 2 to 6. Cox regression analyses were performed to evaluate if stem subsidence and rotation after 2 years, adjusted for age, sex, stem size, standard/high stem offset, and conventional/highly crosslinked polyethylene, could predict later clinical aseptic failure of the stem. We identified 32 stem failures (27 revisions, five radiological failures) at 14 years median followup (range, 3-18 years). Ten-year stem survival was 94% (95% confidence interval [CI], 90%-96%). Stem subsidence at 2 years (adjusted hazard ratio [HR], 6.0; 95% CI, 2.5-15; p < 0.001) and retrotorsion of the stem (adjusted HR, 1.7; 95% CI, 1.1-2.5; p = 0.018) were associated with later stem failure. Further risk factors were male sex (subsidence analysis HR, 6.9; p > 0.001), use of the two smallest stem sizes (HRsize 1, 8.0; p > 0.001, HRsize 2, 1 [reference], HRsize 3+, 0.06; p = 0.035), and the high offset option (HR, 3.1; p = 0.005). Stem subsidence and retrotorsion at 2 years can predict later failure in the Spectron EF Primary stem, consistent with earlier findings on composite-beam cemented stems. Small stem size and high-offset stems comprise the main group of underperforming stems. We recommend that premarket small-scale RSA studies be performed after any design change to a THA femoral component, because even seemingly minor design changes may unexpectedly result in inferior performance.
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| 5. |
- Johanson, Per-Erik, et al.
(author)
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Wear measurements with use of radiostereometric analysis in total hip arthroplasty with obscured femoral head
- 2020
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In: Journal of Orthopaedic Research. - : Wiley. - 0736-0266 .- 1554-527X. ; 38:9, s. 2040-49
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Journal article (peer-reviewed)abstract
- Radiostereometric analysis (RSA) has evolved as gold standard in the evaluation of wear and especially as regards novel hip implant materials. However, several cup shell materials and articulation types used in total hip arthroplasty (THA) cannot be studied due to poor radiographic visibility of the femoral head (FH). We addressed this problem with use of a point transfer function in the RSA software to indirectly measure FH translations with use of stem markers. In a base examination, the stem marker segment and cup center, as an approximation for the FH center position, were mathematically coupled. Thereafter, in subsequent examinations, we used the point transfer function to calculate FH positions from stem marker positions. To determine the variance of the difference of directly and indirectly measured FH positions, four stem marker configurations were studied in THAs with radiographically visible FHs. For the axis with least variance we also compared directly and indirectly measured translation up to 7 years. Finally, we applied the method in a ceramic-on-ceramic (COC) articulation and measured proximal translation up to 7 years and also estimated precision. Vertical translations had the smallest variation between measured and calculated FH position. Directly and indirectly measured vertical FH translation correlated well but indirect measurements had increased variance. Proximal steady-state penetration rate in uncemented COC THA was -0.003 (SD 0.021) mm/year with 99% precision along the vertical axis measuring 0.34 mm. The point transfer function can be used to measure proximal FH penetration, but with less precision than direct RSA.
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| 6. |
- Keiller, Thom, et al.
(author)
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No difference in clinical outcome but in RSA in total knee arthroplasty with the ATTUNE vs. the PFC Sigma: a randomized trial with 2-year follow-up
- 2023
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In: Acta Orthopaedica. - 1745-3674 .- 1745-3682. ; 94, s. 560-569
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Journal article (peer-reviewed)abstract
- Background and purpose — Despite usage of the ATTUNE total knee arthroplasty (TKA) for about 10 years, few randomized trials exist. We evaluated whether the ATTUNE CR design showed improved clinical results compared with the PFC Sigma CR after 2 years and if there was a difference in tibial component migration. Patients and methods — 96 patients with knee osteoar-thritis were randomly treated with cemented ATTUNE or PFC Sigma TKA. 42 patients with the ATTUNE and 48 with the PFC Sigma attended the 2-year follow-up. Patient-reported outcome measurements (PROMs), migration measured with RSA, implant position, and the development of radiolucent zones were studied. Non-parametric tests and repeated measures analysis were used at the statistical evaluation. Results — The Oxford Knee Score (OKS) at 2 years (primary outcome) and neither of the secondary PROM outcomes differed between the groups (mean difference OKS ATTUNE – PFC: –0.08, 95% confidence interval [CI] –2.9 to 2.7). RSA showed posterior tilt of the tibial component in the ATTUNE group with proximal lift-off anteriorly and subsidence of the tibial tray posteriorly. In contrast, the PFC Sigma tibial component tilted forward (mean difference ATTUNE – PFC: –0.7°, CI –1.1° to –0.4°) with maximum subsidence in the front and maximum lift-off of the posterior edge. The postoperative implant positions and the extension of radiolucent lines around the tibial component at 2 years did not differ. Conclusion — We found no significant differences in clinical outcome between the 2 groups but minor differences in migration pattern of the tibial component. The clinical long-term significance of this finding if any is not known.
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| 7. |
- Mohaddes, M., et al.
(author)
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Promising early results for trabecular metal acetabular components used at revision total hip arthroplasty: 42 acetabular revisions followed with radiostereometry in a prospective randomised trial
- 2017
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In: Bone & Joint Journal. - : British Editorial Society of Bone & Joint Surgery. - 2049-4394 .- 2049-4408. ; 99B:7, s. 880-886
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Journal article (peer-reviewed)abstract
- Aims The aim of this study was to compare the incidence of aseptic loosening after the use of a cemented acetabular component and a Trabecular Metal (TM) acetabular component (Zimmer Inc., Warsaw, Indiana) at acetabular revision with bone impaction grafting. A total of 42 patients were included in the study. Patients were randomised to receive an allpolyethylene cemented acetabular component (n = 19) or a TM component (n = 23). Radiostereometric analysis and conventional radiographic examinations were performed regularly up to two years post-operatively or until further revision. The proximal migration was significantly higher in the cemented group. At two years, the median proximal migration was 1.45 mm and 0.25 mm in the cemented and TM groups, respectively (p = 0.02). One cemented component was revised due to dislocation. There were no revisions in the TM group. Lower proximal migration in the TM group suggests that this design might be associated with a lower risk of aseptic loosening in the long term compared with an all polyethylene cemented component. Longer follow-up is required to confirm the clinical advantages of using this component at acetabular revision.
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| 8. |
- Shareghi, Bita, et al.
(author)
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Clinical evaluation of model-based radiostereometric analysis to measure femoral head penetration and cup migration in four different cup designs.
- 2017
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In: Journal of orthopaedic research : official publication of the Orthopaedic Research Society. - : Wiley. - 1554-527X. ; 35:4, s. 760-767
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Journal article (peer-reviewed)abstract
- In conventional Radiostereometric analysis (RSA) implants with attached tantalum markers are frequently used, which may be difficult to visualize. This problem can be avoided with model-based RSA (MBRSA), but it is uncertain if this method has the same precision as marker-based RSA. We evaluated the influence of cup design for the precision of MBRSA in 4 uncemented cups to study if the design had any influence on the precision. Stereo radiographs were analyzed postoperatively (double-examinations) and after 2 years (single examinations). The difference between the double-examinations was used to compute the precision for the methods and for each type of implant. Femoral head penetration and cup translation up to 2 years were compared using marker-based RSA as reference. The precision of proximal penetration and migration measurements did not differ between the methods for Trilogy, TMT and ABG. For Ringloc design a poorer precision was observed using MBRSA. Comparison between the methods regarding proximal penetration and cup migration at 2 years did not differ for 3 of the designs (p= 0.12-0.91). However, for the group with porous plasma sprayed surface (Ringloc) a significant difference between the methods was observed (ppenetration <0.01 and pmigration <0.01). Poorer precision, different penetration and migration values at 2 years for one of the designs indicate that the resolution of MBRSA might vary depending on surface coating and implant geometry. Therefore we conclude that the resolution of MBRSA has to be studied for each type of basic cup design. This article is protected by copyright. All rights reserved.
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| 9. |
- Shareghi, Bita, et al.
(author)
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Femoral Head Penetration of Vitamin E-Infused Highly Cross-Linked Polyethylene Liners A Randomized Radiostereometric Study of Seventy Hips Followed for Two Years
- 2015
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In: Journal of Bone and Joint Surgery-American Volume. - : Ovid Technologies (Wolters Kluwer Health). - 0021-9355 .- 1535-1386. ; 97A:16, s. 1366-1371
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Journal article (peer-reviewed)abstract
- Background: Highly cross-linked polyethylene infused with vitamin E (E-poly) was developed to increase oxidative resistance without affecting mechanical properties. We evaluated this type of polyethylene in a randomized clinical study that used radiostereometric analysis. Our objective was to compare the early-term femoral head penetration of an E-poly liner with that of a heat-treated polyethylene liner, ArComXL. We hypothesized that the clinical outcome at two years following total hip arthroplasty would be unaffected by the choice of polyethylene. Methods: In this prospective study, sixty-one patients (seventy hips) with noninflammatory hip osteoarthritis and a median age of fifty-eight years were randomized to receive either an implant with an E-Poly or a heat-treated highly crosslinked polyethylene liner. The patients were followed for two years and evaluated at three time points (three months, one year, and two years). Results: The median proximal penetration in the E-poly group increased from 0.04 mm at three months to 0.06 mm at two years of follow-up. Corresponding values for the ArComXL group were 0.03 mm and 0.10 mm. In both groups, significantly increased penetration was observed between three months and two years (E-poly, p = 0.02; ArComXL, p < 0.001), but between one and two years, the increase was significant only in the control group (E-poly, p = 0.23; ArComXL, p = 0.002). Conclusions: The femoral head penetration of E-poly was very low at two years. Whether the increase observed between three months and two years was caused by creep, deformation, wear, or a combination of these cannot be determined by our study. There were no significant differences observed in femoral head penetration rates between E-poly and ArComXL. Currently, the theoretical advantages of E-poly remain to be confirmed.
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| 10. |
- Shareghi, Bita, et al.
(author)
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Pelvic tilt between supine and standing after total hip arthroplasty an RSA up to seven years after the operation
- 2021
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In: Journal of Orthopaedic Research. - : Wiley. - 0736-0266 .- 1554-527X. ; 39:1, s. 121-129
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Journal article (peer-reviewed)abstract
- The pose of the prosthetic components after total hip arthroplasty (THA) is commonly evaluated on conventional radiographs. Any change of the pelvic position after the operation in supine and between supine and standing position with time will influence validity of the measurements. We evaluated the changed pelvic tilt angle (PTA) in supine and standing position up to 7 years after operation. The aims of our study were (a) to evaluate if the PTA change over time after THA, (b) to assess any difference in PTA between supine and standing positions, and (c) to investigate whether factors such as gender, the condition of the opposite hip or low-back pain have any influence on PTA after THA. Repeated radiostereophotogrammetric radiographs of 106 patients were studied. Patients had been examined in the supine position postoperatively, and in both supine and standing positions at 6 months and 7-year follow-up. Measurements of supine patients showed an increasing mean posterior pelvic tilt over time. From supine to standing, the pelvis tilted in the opposite direction. At 6 months, the mean anterior tilt was 3.6 degrees +/- 3.8 degrees (confidence interval [CI]: 2.8 degrees to 4.3 degrees) which increased to 6.4 degrees +/- 3.9 degrees (CI: 5.7 degrees to 7.2 degrees) at 7 years. The mean changes in pelvic rotations around the longitudinal and sagittal axis were less than 1 degree, in both positions. In individual patients, this change reached about 11.0 degrees in supine and 18.0 degrees when standing.
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| 11. |
- Shareghi, Bita, et al.
(author)
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Wear of Vitamin E-Infused Highly Cross-Linked Polyethylene at Five Years
- 2017
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In: Journal of Bone and Joint Surgery-American Volume. - : Ovid Technologies (Wolters Kluwer Health). - 0021-9355 .- 1535-1386. ; 99:17, s. 1447-1452
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Journal article (peer-reviewed)abstract
- Background: In an earlier study with a 2-year follow-up of uncemented cups, we had reported low femoral-head penetration of vitamin E-infused highly cross-linked polyethylene liners (E1) compared with highly cross-linked liners without vitamin E (ArComXL). We studied the penetration rate of E1 compared with that of ArComXL, with a focus on changes occurring between 2 and 5 years after total hip arthroplasty. Methods: In this randomized controlled study, we performed radiostereometric analysis of the penetration rate up to 5 years in 63 hips. Results: During the total period of observation, the median proximal penetration for E1, 0.13 mm (mean, 0.11 mm [95% confidence interval (CI), 0.08 to 0.14 mm]), was lower than that for ArComXL, 0.20 mm (mean, 0.22 mm [95% CI, 0.17 to 0.26 mm]). The median proximal penetration rate between 2 and 5 years was 0.02 mm/yr (mean, 0.01 mm/yr [95% CI, 0.01 to 0.02 mm/yr]) for E1 and 0.04 mm/yr (mean, 0.04 mm/yr [95% CI, 0.03 to 0.05 mm/yr) for ArComXL. The corresponding median total (i.e., 3-dimensional resultant) penetration rates were 0.04 mm/yr (mean, 0.04 mm/yr [95% CI, 0.03 to 0.05 mm/yr]) for E1 and 0.07 mm/yr (mean, 0.08 mm/yr [95% CI, 0.06 to 0.10 mm/yr]) for ArComXL. Conclusions: From years 2 to 5, we observed increased penetration in both groups. The penetration rate was higher for ArComXL, resulting in more proximal and total penetration at 5 years than for E1. Level of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.
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| 12. |
- Zügner, Roland, et al.
(author)
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Gait pattern in patients treated with a total hip arthroplasty due to an acute displaced cervical neck fracture: a randomised comparison between 29 cases with a cemented femoral stem and 16 cases with an uncemented femoral stem
- 2024
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In: HIP International. - 1120-7000 .- 1724-6067. ; 34:3, s. 421-427
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Journal article (peer-reviewed)abstract
- Background: The choice between cemented or uncemented stem fixation in the treatment of a femoral neck fracture may influence patient rehabilitation and the resulting gait pattern, due to potential differences in implant positioning and fixation. We used gait analysis to study temporal gait parameters, hip kinematics and kinetics in patients who, 2 years previously, had been randomised to treatment with a cemented or uncemented stem and due to an acute femoral neck fracture. Methods: 45 Patients implanted with a cemented Lubinus SP II (n = 29) and an uncemented (n = 16) Corail stem were studied. Gait analysis was performed using a 16-camera motion capture system and force plates. 28 subjects served as controls. Temporal gait parameters, hip kinematics and kinetics were analysed. The patients had no or minimum pain (median Harris pain score 44, range 40–44) and the majority had no limp (median Harris limp score 11, range 5–11). Results: Temporospatial gait parameters and abduction-adduction motions and moments did not differ between patients with cemented or uncemented stems (p > 0.05). Patients with cemented stems did, however, show more hip flexion and less extension during walking than those with an uncemented stem (p < 0.05). Moreover, the flexion-extension range was less in the cemented group (p < 0.04). Compared with controls, the hip fracture patients walked more slowly, with a shorter stride length and a longer stance phase. Conclusions: Increased hip flexion and reduced extension in patients using the Lubinus SP II cemented stem could be an effect of its anteverted neck, but this question requires further study. Despite acute treatment with THA, hip fracture patients demonstrated a change in gait pattern compared with controls 2 years after the operation. This suggests that these changes are caused by the presence of an implant, or the soft-tissue trauma partly caused by the surgery than by any degenerative disease present in patients undergoing elective surgery.
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| 13. |
- Zügner, Roland, 1958, et al.
(author)
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Validation of gait analysis with dynamic radiostereometric analysis (RSA) in patients operated with total hip arthroplasty.
- 2017
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In: Journal of orthopaedic research : official publication of the Orthopaedic Research Society. - : Wiley. - 1554-527X .- 0736-0266. ; 35:7, s. 1515-1522
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Journal article (peer-reviewed)abstract
- We simultaneously examined 14 patients with OTS and dynamic radiostereometric analysis (RSA) to evaluate the accuracy of both skin- and a cluster-marker models. The mean differences between the OTS and RSA system in hip flexion, abduction, and rotation varied up to 9.5° for the skin-marker and up to 11.3° for the cluster-marker models, respectively. Both models tended to underestimate the amount of flexion and abduction, but a significant systematic difference between the marker and RSA evaluations could only be established for recordings of hip abduction using cluster markers (p=0.04). The intra-class correlation coefficient (ICC) was 0.7 or higher during flexion for both models and during abduction using skin markers, but decreased to 0.5-0.6 when abduction motion was studied with cluster markers. During active hip rotation, the two marker models tended to deviate from the RSA recordings in different ways with poor correlations at the end of the motion (ICC ≤0.4). During active hip motions soft tissue displacements occasionally induced considerable differences when compared to skeletal motions. The best correlation between RSA recordings and the skin- and cluster-marker model was found for studies of hip flexion and abduction with the skin-marker model. Studies of hip abduction with use of cluster markers were associated with a constant underestimation of the motion. Recordings of skeletal motions with use of skin or cluster markers during hip rotation were associated with high mean errors amounting up to about 10° at certain positions. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.
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