| 1. |
- Bögl, Hans Peter, 1969-
(författare)
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Atypical femoral fractures: Another brick in the wall : On aspects of healing, treatment strategies and surveillance
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Atypical femoral fractures are stress fractures of the femoral subtrochanteric and diaphyseal region. It is a common notion that these fractures heal poorly, if at all. In this thesis we show that patients with atypical femoral fractures have a good capacity to generate bone and therefore heal fractures. In daily practice, these patients have a higher risk for reoperation when compared with patients with a normal femoral fracture. However, this risk is less likely to be dependent on the type of fracture than other factors such as age, gender, comorbidities and survival. Using an implant that protects the fragile proximal femur, the risk for reoperations can be attenuated dramatically. An intramedullary nail with fixation of the femoral neck protects the femur from subsequent hip fractures – the most common complication in elderly patients with any type of femoral shaft fracture.Atypical femoral fractures are difficult to identify in the population. Erroneous diagnosis coding, poor reporting of adverse drug reactions and low accuracy of radiology reports make the identification and surveillance a difficult task. The Swedish Fracture Register has provided the option to register this special fracture since 2015. With its physician-based registration process, it enables researchers and treating physicians to identify and follow these rare fractures longitudinally.
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| 3. |
- Kiritopoulos, Demostenis, et al.
(författare)
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Denosumab prevents acetabular bone loss around an uncemented cup : analysis of secondary outcomes in a randomized controlled trial
- 2022
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Ingår i: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3674 .- 1745-3682. ; 93, s. 709-720
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: Uncemented total hip arthroplasty (THA) is associated with periprosthetic bone loss. In a secondary outcome analysis from a randomized controlled trial, we studied whether denosumab can prevent loss of acetabular periprosthetic bone mineral density (pBMD) in patients who received a trabecular metal cup during uncemented THA.PATIENTS AND METHODS: 64 patients (aged 35-65 years) with unilateral osteoarthritis of the hip were randomized to 2 subcutaneous injections with denosumab or placebo, given 1-3 days post-surgery and 6 months post-surgery. Acetabular pBMD was measured in 5 regions of interest (ROIs) by dual-energy X-ray absorptiometry. Serum markers for bone metabolism were analyzed. Periprosthetic osteoblastic activity, measured as standardized uptake values (SUVs) by [18F] positron emission tomography/computed tomography, was evaluated in 32 of the 64 study patients.RESULTS: After 12 months, patients treated with denosumab had higher pBMD compared with the placebo-treated patients in 4 of 5 ROIs and in sum of ROIs 1-5. After 24 months, the effect on pBMD for patients treated with denosumab declined. Serum markers declined pronouncedly up to 12 months in patients treated with denosumab, but rebounded above baseline levels after 24 months. Patients treated with denosumab had statistically significantly lower SUVs in all ROIs, except ROI 5, after 6 months.INTERPRETATION: Based on this exploratory analysis of secondary endpoints the application of denosumab seems associated with preserved acetabular pBMD, reduced bone metabolism and attenuated periprosthetic osteoblastic activity. However, given the known rebound affects after discontinuation of denosumab treatment, these effects cannot be expected to persist. If prolonged treatment or shift to other regimes would be beneficial to reduce the risk of cup loosening is yet to be investigated.
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| 4. |
- Mahmood, Sarwar, 1975-
(författare)
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Leg length discrepancy and femoral offset after total hip arthroplasty : clinical and radiological studies
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Every year, about 1 million patients worldwide and 16000 patients in Sweden undergo total hip arthroplasty (THA). This surgical intervention is considered a successful, safe and cost-effective procedure to regain pain-free mobility and restore hip joint function in patients suffering from severe hip joint disease or trauma. Besides relieving the pain, restoration of biomechanical forces around the hip with appropriate femoral offset (FO), leg length and proper component position and orientation are important goals. The radiographic preoperative planning and postoperative evaluation of these parameters require good validity, interobserver reliability and intraobserver reproducibility. It remains controversial as to how much postoperative leg length discrepancy (LLD) and FO change are acceptable. Generally, lengthening of the operated leg ≥ 10mm and FO reduction of the operated hip > 5mm should be avoided by using preoperative radiological templating and intraoperative measurement methods. There is no consensus on the association between LLD and FO and outcome after THA.The aims of this thesis were to:1. To determine the influence of non-corrected LLD after THA on patients’ reported hip function and quality of life (QoL).2. To study the association of global FO changes after THA with patients’ reported hip function, QoL and abductor muscle strength.3. To evaluate the concurrent validity of the Sundsvall method of measuring postoperative global FO by comparing it to a standard method and to evaluate the interobserver reliability and intraobserver reproducibility of measurement of postoperative global FO, LLD and acetabular cup inclination and anteversion.4. To analyse the postoperative radiographs of THA patients with leg lengthening and FO reduction to determine whether the problem is located in the stem, cup or both.Study I: A prospective cohort study of 174 patients with unilateral osteoarthritis (OA), comparing patients with lengthening ≥ 10mm, restoration (between 9 mm lengthening and 5 mm shortening) or shortening > 5 mm of the operated leg after THA. Follow up was 12–15 months. We found that a LLD of up to 20 mm did not influence the functional outcome (WOMAC) or QoL (EQ-5D). However, the lengthening group showed less improvement in WOMAC and more use of a shoe lift.Study II: A prospective cohort study of 222 patients with unilateral hip OA, comparing patients with decreased global FO (> 5 mm reduction), restored FO (within 5 mm restoration), and increased FO (> 5 mm increment) after THA. Follow up was was 12–15 months. The unadjusted results showed that the decreased FO group had a worse WOMAC index, less abductor muscle strength, and more use of walking aids. When these results were adjusted for possible confounding factors, only global FO reduction was statistically significantly associated with reduced abductor muscle strength. The incidence of residual hip pain and analgesics use was similar in the 3 groups.Study III: A prospective cohort study of 90 patients with primary unilateral OA treated with THA. Global FO using the Sundsvall method, global FO (standard method), LLD, acetabular cup inclination and anteversion were measured on postoperative radiographs. The interobserver reliability and intraobserver reproducibility were tested using three independent observers. We found that the Sundsvall method is as reliable as the standard method and the evaluated radiographic measurement methods have the required validity and reliability to be used in clinical practice.Study IV: A prospective cohort study of 174 patients with unilateral primary OA treated with THA. LLD and global FO were measured on postoperative radiographs. Patients with lengthening of the operated leg ≥ 10mm (n=41) and patients with reduction of global FO > 5mm (n=58) were further studied to investigate the amount of lengthening and global FO reduction that took place in the stem and in the cup compared with the contralateral side. The interobserver reliability and intraobserver reproducibility were tested using two independent observers. We found that post-THA lengthening of the operated leg ≥ 10mm was mainly caused by improper placement of the femoral stem, whereas a decrease of global FO > 5 was caused by improper placement of both acetabular and femoral components. The radiological measurement methods used showed substantial to excellent interobserver reliability and intraobserver reproducibility and are therefore clinically useful.The main conclusions of this thesis are:LLD up to 20 mm and reduced global FO more than 5 mm did not influence the functional outcome or quality of life at 12–15 months postoperatively.Lengthening ≥ 10mm was associated with increased use of a shoe lift. A reduction of global FO more than 5 mm compared to the contralateral hip was associated with weaker hip abductor muscles and more use of walking aids. Therefore both should be avoided.The radiographic measurement methods of LLD, global FO, cup inclination and anteversion have the required validity and reliability to be used in clinical practice.Lengthening of the operated leg is mainly caused by improper femoral stem positioning while global FO reduction results from improper positioning of both acetabular and femoral components. Surgeons should be aware of these operative pitfalls in order to minimize component malpositioning.
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| 6. |
- Nyström, Andreas, et al.
(författare)
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Denosumab Prevents Early Periprosthetic Bone Loss After Uncemented Total Hip Arthroplasty : Results from a Randomized Placebo-Controlled Clinical Trial
- 2020
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Ingår i: Journal of Bone and Mineral Research. - : Wiley. - 0884-0431 .- 1523-4681. ; 35:2, s. 239-247
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Tidskriftsartikel (refereegranskat)abstract
- Implant loosening is the most common indication for revision surgery after total hip arthroplasty (THA). Although bone resorption around the implants plays a pivotal role in the pathophysiology of loosening, it is unknown whether potent early inhibition of osteoclasts could mitigate this process and thus reduce the need for revision surgery. We performed a randomized, double-blind, placebo-controlled phase 2 trial in 64 patients aged 35 to 65 years with unilateral osteoarthritis of the hip. They underwent surgery with an uncemented THA and were randomized to either two subcutaneous doses of denosumab (n = 32) or placebo (n = 32) given 1 to 3 days and 6 months after surgery. Patients were followed for 24 months. Primary outcome was periprosthetic bone mineral density (BMD) of the hip at 12 months as measured by dual-energy X-ray absorptiometry (DXA). In addition, [18 F] sodium fluoride positron emission tomography/CT (F-PET) was performed in half of the patients for analysis of periprosthetic standardized uptake value (SUV). Analyses were made according to intention-to-treat principles. The trial was registered at ClinicalTrials.gov 2011-001481-18, NCT01630941. Denosumab potently inhibited early periprosthetic bone loss. After 12 months, BMD in the denosumab group was 32% (95% confidence interval [CI] 22-44) higher in Gruen zone 7 and 11% (95% CI 8-15) higher in zones 1 to 7. After 24 months, the difference in BMD between groups had decreased to 15% (95% CI 4-27) in zone 7 and 4% (95% CI 0-8) in zones 1 to 7. In both groups, SUV increased after surgery, but the increase was less pronounced in the denosumab group. Biochemical markers of bone metabolism decreased in the denosumab group in the first 12 months, but a rebound effect with marker concentrations above baseline was observed after 24 months. Denosumab potently prevents early periprosthetic bone loss after uncemented THA; however, the effect diminishes after discontinuation of treatment. Further research is needed to determine whether this bone loss will prove to be of clinical importance and, if so, whether the positive effect observed in this study could be preserved by either prolonged treatment with denosumab or additional antiresorptive treatment.
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| 7. |
- Nyström, Andreas, 1972-
(författare)
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Uncemented Total Hip Arthroplasty : Aspects on Bone Biology, Implant Fixation, Periprosthetic Bone Remodeling, Bone Mineral Density and Effects of Denosumab
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Uncemented total hip arthroplasty (THA) is associated with loss of periprosthetic bone mineral density (BMD). The collum femoris preserving (CFP) stem lost 28% of proximal BMD at 2 years. The overall purpose of this thesis was to study the long-term results of the CFP stem in BMD and implant stability (study III) and whether periprosthetic BMD can be preserved with denosumab (study I). Secondary objectives were to evaluate a CT-based technique as an alternative to radiostereometric analysis (RSA) and investigate the reliability, agreement, and precision of periprosthetic [18F]-fluoride PET/CT (F-PET). In study I, a randomized controlled trial, we studied the effect of denosumab on 1) periprosthetic BMD by dual-energy x-ray absorptiometry (DXA), 2) periprosthetic bone formation by F-PET, and 3) serum markers of bone turnover. We found that denosumab prevents early periprosthetic bone loss and reduces periprosthetic and systemic bone turnover. Study II is a methodologic-, multicenter study investigating the precision of low-dose CT-based implant motion analysis (CTMA). We determined the precision of CTMA by repeated measures and found it to be high. In study III we examined the long-term results of the CFP stem. The cohort from a previous, prospective study on the CFP stem was followed up for a minimum of 8 years with DXA and RSA. Periprosthetic BMD was not restored, and further bone loss was seen in the proximal part of the femur; however, the stems appeared stable on RSA. In study IV, we looked at the reliability, agreement, and precision of periprosthetic F-PET. F-PET investigations from study I were analyzed twice by two independent observers, at least 3 weeks apart. Reliability was excellent, agreement was high, and precision was moderate between and within observers. In conclusion, denosumab prevents periprosthetic BMD loss and the CFP stem shows continuous periprosthetic bone loss 8 years after surgery, but the implants remain stable. In addition, this thesis shows that CTMA is a precise method and a viable alternative to RSA. Finally, it demonstrates that periprosthetic F-PET is a reliable method with high inter- and intraobserver agreement.
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| 8. |
- Sotiriou, Dimitrios, et al.
(författare)
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Is two-stage revision surgery for infected hip arthroplasty worth the suffering, resources and results compared to one-stage?
- 2022
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Ingår i: HIP International. - Uppsala Univ, Dept Orthopaed, Cty Council Gavleborg, Gavle Hosp, Gavle, Sweden. Uppsala Univ, Ctr Res & Dev, Cty Council Gavleborg, Gavle, Sweden. : SAGE Publications. - 1120-7000 .- 1724-6067. ; 32:2, s. 205-212
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Periprosthetic joint infection (PJI) is the most serious complication of total hip arthroplasty. The treatment is usually revision in either 1 or 2 stages. This study analyses revision with impaction bone grafting for periprosthetic joint infection of the hip and compares 1- and 2-stage strategies. Patients and methods: We reviewed 55 consecutive cases (54 patients) of revision arthroplasty for PJI carried out at our hospital between 2002 and 2016. Of these, 46 were 2-stage procedures. 21 had vancomycin mixed in with the bone graft, and all had gentamycin-containing bone cement. The total perioperative blood loss, duration of operation, and length of hospital stay were recorded. Clinical and radiological results were analysed for 48 hips at 2-16 years follow-up. Results: No PJI remained at follow-up. 3 patients (6%) had undergone revision for all causes. 1 had radiological signs of mechanical loosening but was not revised. 2-stage procedures had a significantly longer operating time (409 vs. 238 min) and hospital stay (34 vs. 13 days), greater blood loss (2764 vs. 1638 ml), and lower mean functional hip score (15.9 vs. 17.5) at follow-up than the one-stage procedures. Interpretation: Revision total hip arthroplasty for PJI with vancomycin-loaded impaction bone grafting is a safe method that achieves both the restoration of bone stock and resolution of the infection. This single-stage procedure could therefore be the new gold standard for treatment of non-complicated PJI in the hip.
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| 9. |
- Stigbrand, Hampus, et al.
(författare)
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A 2-to 16-Year Clinical Follow-Up of Revision Total Hip Arthroplasty Using a New Acetabular Implant Combined With Impacted Bone Allografts and a Cemented Cup
- 2018
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Ingår i: The Journal of Arthroplasty. - : CHURCHILL LIVINGSTONE INC MEDICAL PUBLISHERS. - 0883-5403 .- 1532-8406. ; 33:3, s. 815-822
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Tidskriftsartikel (refereegranskat)abstract
- Background: Treatment of acetabular bone loss with impaction bone grafting (IBG) at revision total hip arthroplasty is highly dependent on mechanical stability and graft compression for clinical success. Here, we describe a new technique to further compress and stabilize the acetabular graft bed with a thin, perforated titanium shell.Methods: We retrospectively analyzed 170 cases of acetabular revision arthroplasty 7 years (standard deviation 2.8) after IBG combined with a graft-compressing titanium shell implant. The patients were reviewed by clinical score and radiography. Three patients were lost to follow-up. The medical journals of the 33 deceased cases were reviewed for any reoperation. Of the 170 cases, 74 had a cavitary acetabular bone defect, 93 had combined segmental and cavitary bone defects, and 3 had a pelvic dissociation. Bone graft incorporation was assessed and correction of the hip center of rotation was calculated. Results: Five cases (3%) were reoperated for mechanical loosening. One more was assessed as loose but asymptomatic and was not planned for revision. There were 3 reoperations for recurrent dislocation, 2 for deep infection and 1 for technical error. Reoperation for any reason, as the end point of survivorship, showed a survival rate of 92% after 10 years. Hip score according to Merle, d'Aubigne, and Postel increased from 10.8 (preoperatively) to 16.4 at follow-up. The clinical and radiological results were excellent.Conclusion: IBG combined with the compressing shell results in excellent results for this challenging condition.
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| 10. |
- Stigbrand, Hampus, et al.
(författare)
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A 3-to 18-Year Follow-Up of Revision Total Hip Arthroplasty With Impacted Bone Allografts and Cemented Lubinus SP II Stem. Clinical, Radiographic, and Survivorship Analysis With Comparison to the Literature
- 2017
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Ingår i: The Journal of Arthroplasty. - : Elsevier BV. - 0883-5403 .- 1532-8406. ; 32:9, s. 2810-2814
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Tidskriftsartikel (refereegranskat)abstract
- Background: We present the first medium- to long-term follow-up of revision total hip arthroplasty using impaction bone grafting (IBG) combined with the matte and collared Lubinus SP II stem for cases of severe osteolysis and stem loosening.Methods: Sixty-nine femoral revisions were identified for 67 patients consecutively operated with revision femoral arthroplasty using IBG and a cemented Lubinus SP II stem. The mean age was 69 years (standard deviation, 9.9). We retrospectively analyzed 68 cases (1 was lost to follow-up). At the time of the revision surgery, all had substantial femoral bone loss. Fifteen of the revisions were performed due to deep infection. The patients were analyzed by clinical score and radiography.Results: At follow-up, 4 femoral components (6%) had been rerevised or assessed as failure. Of these 4, 3 were assessed as mechanical failure, and 1 for dislocation; none was for infection. Three cups (4%) had been revised for dislocation; 1 of these also had a stem exchange. Three cases (4%) had been reoperated for a periprosthetic fracture in distal femur without stem exchange. Radiologic results were excellent and the clinical Merle d'Aubigne-Postel score had improved from a mean of 12.2 preoperatively to 17.5 at follow-up.Conclusion: IBG combined with the Lubinus SP II stem is safe and results in a low rate of periprosthetic fractures and dislocations. The medium-to long-term clinical result was excellent, with regeneration of living bone in the femur.
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