Project description:BackgroundTotal ankle arthroplasty (TAA) has become increasingly popular in the treatment for end-stage ankle arthritis in recent decades. However, there is limited evidence regarding the long-term clinical outcomes and complication rates of modern TAA implants.MethodsThis study presents a follow-up on a previous cohort involving 78 patients (81 ankles) who underwent Salto Talaris fixed-bearing TAA to treat end-stage arthritis, with a mean postoperative follow-up of 5.2 years. The aim of this follow-up study was to assess the radiographic (33 patients, 35 ankles) and clinical (48 patients, 50 ankles) results from the original cohort at a mean of 10.7 years (range, 7.8-14 years).ResultsAt a mean of 10.7 years, the Kaplan-Meier estimated survivorship was 84.2% (95% CI, 71.9%-98.6%). For the patients reviewed, we did not find any change in patient-reported outcomes between an average 5- and 11-year follow-up. Measured total range of motion and plantarflexion did not change between 1 and 11 years, but dorsiflexion was measured as decreasing by an average of 4 degrees (P < .02).ConclusionIn this longer-term follow-up of a limited cohort, we found that Salto Talaris fixed-bearing TAA demonstrated good long-term survival with relatively low rates of revision or other complications. Patient-reported outcome and range of motion measures revealed good stability.Level of evidenceLevel III, therapeutic.
Project description:This multicenter prospective cohort study assessed the safety and performance of the Trabecular Metal Total Ankle System (TM Ankle; Zimmer) for primary total ankle arthroplasty (TAA).MethodsOne hundred and twenty-one consecutive patients qualifying for primary TAA were enrolled in the study. All patients received the TM Ankle implant. Clinical outcome examinations and radiographic evaluations were conducted at 6 weeks, 6 months, 1 year, 2 years, and 3 years. Patient-reported outcome measures (PROMs) were evaluated with use of the EuroQol-5 Dimensions questionnaire (EQ-5D), Ankle Osteoarthritis Scale (AOS), American Orthopaedic Foot & Ankle Society questionnaire (AOFAS), and patient satisfaction at each time point. Complications were classified according to the Canadian Orthopaedic Foot and Ankle Society (COFAS) system.ResultsThe average AOFAS, EQ-5D, AOS pain, and AOS difficulty scores showed significant improvement at 6 weeks, 6 months, 1 year, 2 years, and 3 years as compared with the preoperative baseline (p < 0.001). The Kaplan-Meier survival estimate for revision when used in primary cases was 97.35% at 3 years. During the 3 years of follow-up, 9 patients showed abnormal radiographic findings. Two ankles had intraoperative complications, 38 had complications that were non-surgical or device-related, and 3 ankles underwent revision.ConclusionsThe results of the present study indicated that patient well-being significantly increased following TAA with use of the TM Ankle. Radiographic parameters also demonstrated a low incidence of abnormal findings.Level of evidencePrognostic Level III. See Instructions for Authors for a complete description of levels of evidence.
Project description:We previously reported on the metal ion concentrations of cobalt, chromium, and titanium that were found in the serum of patients three years after they had undergone primary total hip arthroplasty as compared with the concentrations found in the serum of control patients who did not have an implant. This study is a concise update on the serum metal levels found in a cohort of these patients ten years after the time of hip implantation. Of the original seventy-five subjects, metal ion levels were available for forty patients (53%). Ten patients (hybrid group) had received a hybrid total hip replacement that consisted of a modular cobalt-alloy femoral stem with a cobalt-alloy femoral head that had been inserted with cement and a titanium acetabular socket that had been inserted without cement. Nine patients (cobalt-chromium [CoCr] group) had received an implant with an extensively porous-coated modular cobalt-alloy femoral stem and femoral head along with a titanium acetabular socket; the femoral and acetabular components had each been inserted without cement. Eight patients (titanium group) had undergone insertion of a proximally porous-coated modular titanium-alloy femoral stem with a cobalt-alloy femoral head and a titanium acetabular socket; the femoral and acetabular components had each been inserted without cement. Thirteen patients (control group) from the original control group of patients who had not received an implant served as control subjects. Serum metal levels were measured with use of high-resolution sector field inductively coupled plasma mass spectrometry. The hybrid total hip arthroplasty group had mean cobalt levels that were 3.2 times higher at 120 months than they were at baseline, and the cobalt levels in that group were significantly higher than those in the titanium total hip arthroplasty group at thirty-six, sixty, eighty-four, ninety-six, and 120 months (p < 0.01). The hybrid group had mean chromium levels that were 3.9 times higher at 120 months than they were at baseline, and the CoCr total hip arthroplasty group had chromium levels that were 3.6 times higher at 120 months than they were at baseline. The serum titanium levels were higher in the titanium group at all follow-up time intervals as compared with the levels in all other groups, and the level in the titanium group at 120 months was eighteen times higher than it was at baseline (p < 0.01). Patients with well-functioning primary metal-on-polyethylene total hip replacements had elevated serum metal levels for as many as ten years postoperatively. Furthermore, metal release at the modular femoral head-neck junctions, rather than passive dissolution from porous ingrowth surfaces, was likely the dominant source of serum cobalt and chromium.
Project description:BackgroundThis study aimed to report the long-term survival of fixed-bearing medial unicompartmental knee arthroplasty (UKA) with a mean of 14-year follow-up, and to determine possible risk factors of failure.MethodsWe retrospectively evaluated 337 fixed-bearing medial UKAs implanted between 2003 and 2014. Demographic and radiographic parameters were measured, including pre-operative and post-operative anatomical femorotibial angle (aFTA), posterior tibial slope (PTS), and anatomical medial proximal tibial angle (aMPTA). Multivariate logistic regression analysis was applied to figure out risk factors.ResultsThe mean follow-up time was 14.0 years. There were 32 failures categorized into implant loosening (n = 11), osteoarthritis progression (n = 7), insert wear (n = 7), infection (n = 4), and periprosthetic fracture (n = 3). Cumulative survival was 91.6% at 10 years and 90.0% at 15 years. No statistically significant parameters were found between the overall survival and failure groups. Age and hypertension were significant factors of implant loosening with odds ratio (OR) 0.909 (p = 0.02) and 0.179 (p = 0.04) respectively. In the insert wear group, post-operative aFTA and correction of PTS showed significance with OR 0.363 (p = 0.02) and 0.415 (p = 0.03) respectively. Post-operative aMPTA was a significant factor of periprosthetic fracture with OR 0.680 (p < 0.05).ConclusionsThe fixed-bearing medial UKA provides successful long-term survivorship. Tibial component loosening is the major cause of failure. Older age and hypertension were factors with decreased risk of implant loosening.
Project description:Background and purpose - Differences in stress distribution in a mobile-bearing and fixed-bearing unicompartmental knee arthroplasty (UKA) design might lead to a difference in fixation of the tibial component. We compared tibial component migration of a mobile-bearing (MB) UKA and a fixed-bearing (FB) UKA using radiostereometric analysis.Patients and methods - In a randomized, patient-blinded clinical trial 62 patients received either the MB Oxford UKA or the FB Sigma UKA. The patients were followed for 24 months with radiostereometric analysis. Clinical outcome was assessed with Oxford Knee Score (OKS), RAND-36 and leg extension power.Results - Migration of the tibial components was similar between groups throughout follow-up. At 12 months, MTPM of the tibial component was 0.44?mm (95% CI 0.34-0.55) for the MB group and 0.40?mm (CI 0.31-0.50) for the FB group. Between 12 and 24 months, the tibial components migrated with a median MTPM increase of 0.03?mm (CI -0.02 to 0.08) in the MB group and 0.03?mm (CI -0.02 to 0.07) in the FB group. Continuous migration of the tibial component was found for 1?MB UKA and 2 FB UKAs. Both groups showed similar and clinically relevant improvement in clinical outcome.Interpretation - MB and FB tibial components had similar good fixation and clinical improvement until 2 years. Based on this study, a low 5- to 10-year revision rate can be expected for both implants.
Project description:BackgroundThe treatment of failed ankle replacements is debated, and little is published about the medium- and long-term results of revision implants. We wanted to examine prosthesis survival and physical function at least 5 years after insertion of the Salto XT revision prosthesis.MethodsAll consecutive patients operated with a Salto XT revision prosthesis underwent clinical and radiologic examinations preoperatively and after 3, 12, 24, and 60 months. Complications and reoperations are described, and changes in patient-reported outcome measures and clinical scores are reported.ResultsThirty patients were operated with a Salto XT revision prosthesis between March 2014 and March 2017. Three of these were revised (1 to a fusion and 2 to a new prosthesis), and 3 patients were reoperated with screw removal. A concurrent subtalar fusion was performed on 13 patients, and there was 1 case of likely nonunion after these procedures, but no reoperations. The mean AOFAS score increased from 39.2 (95% CI 30.8-47.5) preoperatively to 75.1 (95% CI 67.3-82.9) after 5 years, and the mean improvement was 34.2 points (95% CI 23.8-44.6). Mean EQ-5D increased from 0.36 (95% CI 0.30-0.42) preoperatively to 0.74 (95% CI 0.64-0.85) after 5 years, an improvement of 0.34 (95% CI 0.19-0.49). Radiolucent lines were present in all but 3 patients. Five-year prosthesis survival was 93% (83.6-100).ConclusionThis is the first study to present medium-term results of this implant. We found good improvement in outcome scores and good implant survival, but also a high prevalence of radiolucent lines.
Project description:Background and purpose - Mobile-bearing total knee prostheses (TKPs) were developed in the 1970s in an attempt to increase function and improve implant longevity. However, modern fixed-bearing designs like the single-radius TKP may provide similar advantages. We compared tibial component migration measured with radiostereometric analysis (RSA) and clinical outcome of otherwise similarly designed cemented fixed-bearing and mobile-bearing single-radius TKPs. Patients and methods - RSA measurements and clinical scores were assessed in 46 randomized patients at baseline, 6 months, 1 year, and annually thereafter up to 6 years postoperatively. A linear mixed-effects model was used to analyze the repeated measurements. Results - Both groups showed comparable migration (p = 0.3), with a mean migration at 6-year follow-up of 0.90 mm (95% CI 0.49-1.41) for the fixed-bearing group compared with 1.22 mm (95% CI 0.75-1.80) for the mobile-bearing group. Clinical outcomes were similar between groups. 1 fixed-bearing knee was revised for aseptic loosening after 6 years and 2 knees (1 in each group) were revised for late infection. 2 knees (1 in each group) were suspected for loosening due to excessive migration. Another mobile-bearing knee was revised after an insert dislocation due to failure of the locking mechanism 6 weeks postoperatively, after which study inclusion was preliminary terminated. Interpretation - Fixed-bearing and mobile-bearing single-radius TKPs showed similar migration. The latter may, however, expose patients to more complex surgical techniques and risks such as insert dislocations inherent to this rotating-platform design.
Project description:ObjectiveThe purpose of this study was to perform a meta-analysis comparing mobile-bearing with fixed-bearing total knee arthroplasty (TKA) in terms of all-cause revision rates, aspetic loosening, knee functional scores, range of motion and radiographic lucent lines and osteolysis.MethodsPubMed, Cochrane Library, Google Scholar and Web of Science were searched up to January 2020. Randomized controlled trials that compared primary mobile-bearing with fixed-bearing TKA, reporting at least one of the outcomes of interest, at a minimum follow-up of 12 months were included. All outcomes of interest were pooled at short-term (< 5 years), mid-term (5 to 9 years) and long-term (> = 10 years) follow-up intervals.ResultsA total of 70 eligible articles were included in the qualitative and statistical analyses. There was no difference between mobile-bearing or fixed-bearing TKA at short-term, mid-term and long-term follow-ups in all outcome measures including all-cause revision rate, aseptic loosening, oxford knee score, knee society score, Hospital for Special Surgery score, maximum knee flexion, radiographic lucent lines and radiographic osteolysis.ConclusionThe current level of evidence demonstrated that both mobile-bearing and fixed-bearing designs achieved excellent outcomes, yet it does not prove the theoretical advantages of the mobile-bearing insert over its fixed-bearing counterpart. The use of either design could therefore be supported based on the outcomes assessed in this study.Level of evidenceLevel II, Therapeutic.
Project description:BackgroundIsolated osteoarthritis of the lateral compartment of the knee is less common than that of the medial compartment, resulting in significantly fewer lateral unicompartmental knee arthroplasties (UKAs) being performed. This study aimed to evaluate results of a fixed-bearing UKA for the treatment of lateral compartment osteoarthritis of the knee.MethodsA prospectively collected cohort of 255 patients undergoing fixed-bearing UKA of the lateral compartment using the Triathlon PKR (Stryker, Warsaw, IND) implant with a minimum 2-year follow-up was reviewed. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, radiographic alignment, complications, reoperations, and revisions were recorded. Patient factors and pre- and post-surgical alignment were assessed for their association with a minimum important change (MIC) of the total WOMAC score.ResultsA total of 246 implants with a mean follow-up of 6.6 years (2-10.8 years) were included (4% lost to follow-up). The total WOMAC score increased from 61.3 ± 3.5 to 85.3 ± 7.5, exceeding the MIC in 215 patients (88%). Exceeding the MIC was not associated with age, body mass index, or alignment. The 5-year implant revision rate was 1.6% (3/187).ConclusionsThe fixed-bearing Stryker Triathlon PKR implant for lateral UKA resulted in good clinical outcomes with a low revision rate at midterm follow-up. Body mass index, age, and pre- and post-surgical alignment did not correlate with the clinical outcome. Long-term follow-up is necessary to determine if the clinical improvement and low revision rate can be maintained.