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- Gudnason, Asgeir, et al.
(författare)
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Implant survival and outcome after rotating-hinge total knee revision arthroplasty : a minimum 6-year follow-up
- 2011
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Ingår i: Archives of Orthopaedic and Trauma Surgery. - : Springer Science and Business Media LLC. - 0936-8051 .- 1434-3916. ; 131:11, s. 1601-1607
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Data on long-time survival and clinical function of rotating hinge knee prostheses used in revision total knee arthroplasty (TKA) are scarce. Method: We evaluate the outcome of 42 revision TKA in 38 patients using the Endo-model rotating hinge total knee prosthesis after a minimum of 6 years, with 10-year implant survival as our primary outcome measure. Only revision TKAs performed due to aseptic loosening were included, and the Swedish Knee Arthroplasty Register was consulted in order to ensure that patients unavailable for clinical follow-up had not been revised elsewhere. Mean follow-up was after 8.8 (6-18) years, mean age at revision surgery was 72 (55-88) years, and most patients had severe medical comorbidities (n = 31). Results: At follow-up, four knees had been re-revised due to aseptic loosening, and five further knees underwent re-revision due to other reasons. With implant revision due to aseptic loosening as the endpoint, 10-year survival was 89.2%, and with implant revision due to any reason 10-year survival was 65.1%. 11 patients (13 knees) eligible for clinical follow-up were evaluated according to the Hospital for Special Surgery score (HSSS), the Knee Society scores (KSS), and by plain radiography. Mean HSSS was 67 (36-90), mean KSS-knee was 85 (73-96), and mean KSS-function was 29 (0-100). Radiography showed that no implant was in need of revision. Conclusion: Our results indicate that revision arthroplasty of the knee with this rotating hinge prosthesis can be performed with satisfactory or good results in an elderly population with severe comorbidities.
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- Hailer, Nils P, et al.
(författare)
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High Metal Ion Levels After Use of the ASR™ Device Correlate With Development of Pseudotumors and T Cell Activation
- 2014
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Ingår i: Clinical Orthopaedics and Related Research. - : Ovid Technologies (Wolters Kluwer Health). - 0009-921X .- 1528-1132. ; 472:3, s. 953-961
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUNDPseudotumors and immunologic alterations are reported in patients with elevated metal ion levels after resurfacing arthroplasty of the hip. A direct association of increased cobalt and chromium concentrations with the development of pseudotumors has not been established.QUESTIONS/PURPOSE We hypothesized that (1) patients with higher blood cobalt and chromium concentrations are more likely to have pseudotumors develop, (2) elevated cobalt and chromium concentrations correlate with increased activation of defined T cell populations, and (3) elevated metal ion levels, small implant size, cup inclination angle, and patient age are risk factors for the development of pseudotumors.METHODSA single-surgeon cohort of 78 patients with 84 Articular Surface Replacement(®) implants was retrospectively investigated. Between 2006 and 2010, we performed 84 THAs using the Articular Surface Replacement(®) implant; this represented 2% (84/4950) of all primary hip replacements performed during that period. Of the procedures performed using this implant, we screened 77 patients (99%) at a mean of 43 months after surgery (range, 24-60 months). Seventy-one patients were investigated using ultrasound scanning, and cobalt and chromium concentrations in whole blood were determined by high-resolution inductively coupled plasma mass spectrometry. Differential analysis of lymphocyte subsets was performed by flow cytometry in 53 patients. Results of immunologic analyses were investigated separately for patients with and without pseudotumors. Pseudotumors were found in 25 hips (35%) and were more common in women than in men (p = 0.02). Multivariable regression analysis was performed to identify risk factors for the development of pseudotumors.RESULTSCobalt and chromium concentrations were greater in patients with pseudotumors than in those without (cobalt, median 8.3 versus median 1.0 μg/L, p < 0.001; chromium, median 5.9 versus median 1.3 μg/L, p < 0.001). The percentage of HLA-DR(+)CD4(+) T cells was greater in patients with pseudotumors than in those without (p = 0.03), and the proportion of this lymphocyte subtype was positively correlated with cobalt concentrations (r = 0.3, p = 0.02). Multivariable regression analysis indicated that increasing cobalt levels were associated with the development of pseudotumors (p < 0.001), and that patients with larger implants were less likely to have them develop (p = 0.04); age and cup inclination were not risk factors.CONCLUSIONSWe found a distinct association of elevated metal ion concentrations with the presence of pseudotumors and a correlation of increased cobalt concentrations with the proportion of activated T helper/regulator cells. Thus, the development of soft tissue masses after metal-on-metal arthroplasty could be accompanied by activation of T cells, indicating that this complication may be partly immunologically mediated. Further investigations of immunologic parameters in larger cohorts of patients with metal-on-metal arthroplasties are warranted.LEVEL OF EVIDENCELevel III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.
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- 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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- Lazarinis, Stergios, 1971-, et al.
(författare)
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A prospective cohort study on the short collum femoris preserving (CFP) stem using RSA and DXA : Primary stability but no prevention of proximal bone loss in 27 patients followed for 2 years
- 2013
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Ingår i: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3674 .- 1745-3682. ; 84:1, s. 32-39
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose Short femoral stems have been introduced in total hip arthroplasty in order to save proximal bone stock. We hypothesized that a short stem preserves periprosthetic bone mineral density (BMD) and provides good primary stability. Methods We carried out a prospective cohort study of 30 patients receiving the collum femoris-preserving (CFP) stem. Preoperative total hip BMD and postoperative periprosthetic BMD in Gruen zones 1-7 were investigated by dual-energy x-ray absorptiometry (DXA), stem migration was analyzed by radio-stereometric analysis (RSA), and the Harris hip score (HHS) was determined. Results 2 patients were excluded intraoperatively and 1 patient was revised due to a deep infection, leaving 27 patients for analysis. The mean HHS increased from 49 (24-79) preoperatively to 99 (92-100) after 2 years. DXA after 1 year showed substantial loss of BMD in Gruen zone 7 (-31%), zone 6 (-19%), and zone 2 (-13%, p < 0.001) compared to baseline BMD determined immediately postoperatively. The bone loss in these regions did not recover after 2 years, whereas the more moderate bone loss in Gruen zones 1, 3, and 5 partially recovered. There was a correlation between low preoperative total hip BMD and a higher amount of bone loss in Gruen zones 2, 6 and 7. RSA showed minor micromotion of the stem: mean subsidence was 0.13 (95% CI: -0.28 to 0.01) mm and mean rotation around the longitudinal axis was 0.01 (95% CI: -0.1 to 0.39) after 2 years. Interpretation We conclude that substantial loss in proximal periprosthetic BMD cannot be prevented by the use of a novel type of short, curved stem, and forces appear to be transmitted distally. However, the stems showed very small migration-a characteristic of stable uncemented implants.
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- Lazarinis, Stergios, et al.
(författare)
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Bone loss around a stable, partly threaded hydroxyapatite-coated cup : a prospective cohort study using RSA and DXA
- 2014
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Ingår i: HIP International. - : SAGE Publications. - 1120-7000 .- 1724-6067. ; 24:2, s. 155-166
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Tidskriftsartikel (refereegranskat)abstract
- Study purpose: Aseptic loosening of the acetabular component is the most common reason for revision after primary THA, and periprosthetic demineralisation has been described as a potential cause for this process. The trabeculae-oriented pattern (TOP)-cup is a flat, hydroxyapatite (HA)-coated titanium shell with a threaded rim that was developed in order to minimise periprosthetic bone loss. We hypothesised that this cup provides good primary stability and improves preservation of periprosthetic bone mineral density (BMD). Basic procedures: A prospective cohort study on 30 patients receiving the TOP cup was carried out. Preoperative total hip BMD and postoperative periprosthetic BMD in five periprosthetic regions of interest were investigated by dual energy radiographic absorptiometry (DXA), cup migration was analysed by radiostereometry (RSA), and the Harris hips score (HHS) was determined. Main findings: Mean HHS increased from 49 (24-79) preoperatively to 99 (92-100) after two years. DXA after one year demonstrated substantial BMD loss in the proximal periprosthetic zones 1 (-18%), zone 2 (-16%) and zone 3 (-9%, all p<0.001 when compared with baseline BMD determined immediately postoperatively). The bone loss in these regions did not recover after two years. RSA (performed on 16 patients) showed that only very limited micromotion of the implant occurred: Mean cranial migration was 0.01 mm (95% confidence interval (CI): -0.09-0.12) and mean inclination decreased by 0.02 degrees (CI: -0.43-0.39) after two years. Conclusion: We conclude that the TOP cup provides good primary stability in the short-term. However, substantial BMD loss in proximal periprosthetic areas indicates that the design of this cup cannot prevent periprosthetic bone loss that has also been observed around other uncemented cups.
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