Anders Henricson

The Swedish Ankle Arthroplasty Register : An analysis of 531 arthroplasties between 1993 and 2005

Background Whether or not ankles can be replaced with reasonable safety has been the subject of debate. We present the results of a nationwide series of total ankle arthroplasties. Patients and methods All Swedish hospitals that implant or have implanted modern three-component ankle prostheses reported demographic data and date of index and revision surgery to a central register. After the data had been introduced into a database, prosthetic survival rates with exchange or permanent extraction of components as endpoint were calculated. Results Of the 531 prostheses implanted, 101 had been revised by June 15, 2006. The overall survival rate at 5 years was 0.78 (95%CI: 0.74–0.82). For the three surgeons who had inserted the majority of the STAR ankles, the survival rates became significantly higher after the first 30 cases had been performed and was estimated to be 0.86 (0.80–0.93) at 5 years. Lower age at index surgery implied increased risk of revision whereas diagnosis or gender did not. Interpretation Ankle replacement is a valuable alternative to arthrodesis. However, replacing an ankle is a demanding procedure and the survival is not comparable to that after hip or knee replacement. It is obvious that with increasing experience, the results—including prosthetic survival—will improve.

10-year survival of total ankle arthroplasties: A report on 780 cases from the Swedish Ankle Register

Background and purpose There is an ongoing need to review large series of total ankle replacements (TARs) for monitoring of changes in practice and their outcome. 4 national registries, including the Swedish Ankle Register, have previously reported their 5-year results. We now present an extended series with a longer follow-up, and with a 10-year survival analysis. Patients and methods Records of uncemented 3-component TARs were retrospectively reviewed, determining risk factors such as age, sex, and diagnosis. Prosthetic survival rates were calculated with exchange or removal of components as endpoint—excluding incidental exchange of the polyethylene meniscus. Results Of the 780 prostheses implanted since 1993, 168 (22%) had been revised by June 15, 2010. The overall survival rate fell from 0.81 (95% CI: 0.79–0.83) at 5 years to 0.69 (95% CI: 0.67–0.71) at 10 years. The survival rate was higher, although not statistically significantly so, during the latter part of the period investigated. Excluding the STAR prosthesis, the survival rate for all the remaining designs was 0.78 at 10 years. Women below the age of 60 with osteoarthritis were at a higher risk of revision, but age did not influence the outcome in men or women with rheumatoid arthritis. Revisions due to technical mistakes at the index surgery and instability were undertaken earlier than revisions for other reasons. Interpretation The results have slowly improved during the 18-year period investigated. However, we do not believe that the survival rates of ankle replacements in the near future will approach those of hip and knee replacements—even though improved instrumentation and design of the prostheses, together with better patient selection, will presumably give better results.

Use of a trabecular metal implant in ankle arthrodesis after failed total ankle replacement

Background and purpose Arthrodesis after failed total ankle replacement is complicated and delayed union, nonunion, and shortening of the leg often occur—especially with large bone defects. We investigated the use of a trabecular metal implant and a retrograde intramedullary nail to obtain fusion. Patients and methods 13 patients with a migrated or loose total ankle implant underwent arthrodesis with the use of a retrograde intramedullary nail through a trabecular metal Tibial Cone. The mean follow-up time was 1.4 (0.6–3.4) years. Results At the last examination, 7 patients were pain-free, while 5 had some residual pain but were satisfied with the procedure. 1 patient was dissatisfied and experienced pain and swelling when walking. The implant-bone interfaces showed no radiographic zones or gaps in any patient, indicating union. Interpretation The method is a new way of simplifying and overcoming some of the problems of performing arthrodesis after failed total ankle replacement.

A survival analysis of 52 Bath & Wessex ankle replacements A clinical and radiographic study in patients with rheumatoid arthritis and a critical review of the literature

Abstract In a series of 52 Bath & Wessex ankle replacements, performed because of rheumatoid arthritis, the probability of the tibial component being without radiographic signs of loosening after 5 years was 65% whereas the corresponding probability for the talar component was only 33%. However, 15 of 25 ankles with a loose talar component and 42 of all 52 ankles were reported improved compared with the preoperative condition at the last visit and there was an 81% probability of not having undergone exchange operation or arthrodesis after 5 years. With proper patient selection we consider ankle replacement a valid solution for rheumatoid arthritis patients. Improved anchorage of the talar component must be the goal of future improvements.

The AES total ankle replacement A mid-term analysis of 93 cases

BACKGROUND There are few studies concerning specific total ankle arthroplasties. This study reports mid-term survival data for the AES prosthesis. METHODS Ninety-three AES ankle arthroplasties were performed by the senior authors. The mean follow-up was 3.5 years. The 5-year survivorship and also the number of simultaneous procedures, reoperations, additional procedures and revisions are analyzed. RESULTS The 5-year survivorship with revision for any reason as end-point was 90%. Simultaneous procedures were performed in 25 patients, deltoid release and subtalar fusion being the most common. There were seven revisions, one due to loosening, and two due to infection, instability and fractures, respectively. Twenty-seven reoperations or additional procedures were performed in 23 patients with a procedure for malleolar impingement being the most common reoperation, and correction of hindfoot varus being the most common reason for an additional procedure. CONCLUSIONS The AES total ankle replacement seems to be a reasonably safe procedure in experienced hands.

Trabecular metal tibia still stable at 5 years: An RSA study of 36 patients aged less than 60 years

Background and purpose Clinical results of total knee replacement (TKR) are inferior in younger patients, mainly due to aseptic loosening. Coating of components with trabecular metal (TM) is a new way of enhancing fixation to bone. We have previously reported stabilization of TM tibial components at 2 years. We now report the 5-year follow-up of these patients, including RSA of their TM tibial components. Patients and methods 22 patients (26 knees) received an uncemented TM cruciate-retaining tibial component and 19 patients (21 knees) a cemented NexGen Option cruciate-retaining tibial component. Follow-up with RSA, and clinical and radiographic examinations were done at 5 years. In bilaterally operated patients, the statistical analyses included only the first-operated knee. Results Both groups had most migration within the first 3 months, the TM implants to a greater extent than the cemented implants. After 3 months, both groups stabilized and remained stable up to the 5-year follow-up. Interpretation After a high initial degree of migration, the TM tibia stabilized. This stabilization lasted for at least 5 years, which suggests a good long-term performance regarding fixation. The cemented NexGen CR tibial components showed some migration in the first 3 months and then stabilized up to the 5-year follow-up. This has not been reported previously.

Outcome After Salvage Arthrodesis for Failed Total Ankle Replacement.

Background: In cases with total ankle replacement (TAR) failure, a decision between revision TAR and salvage arthrodesis (SA) must be made. In a previous study, we analyzed revision TAR and found low functional outcome and satisfaction. The aims of the current study were to analyze SA concerning failure rate and patient-related outcome measures (PROMs). Methods: Until September 2014, a total of 1110 primary TARs were recorded in the Swedish Ankle Registry. Of the 188 failures, 118 were revised with SA (and 70 with revision TAR). Patient- and implant-specific data for SA cases were analyzed as well as arthrodesis techniques. Failure of SA was defined as repeat arthrodesis or amputation. Generic and region-specific PROMs of 68 patients alive with a solid unilateral SA performed more than 1 year before were analyzed. Results: The first-attempt solid arthrodesis rate of SA was 90%. Overall, 25 of 53 (47%) patients were very satisfied or satisfied. Mean Self-reported Foot and Ankle Score (SEFAS) was 22 (95% confidence interval 20-24), Euro Qol–5 Dimensions 0.57 (0.49-0.65), Euro Qol–Visual Analogue Scale 59 (53-64), Short Form-36 physical 34 (31-37) and mental 50 (46-54). The scores and satisfaction were similar to those after revision TAR but the reoperation rate was significantly lower in SA (P < .05). Conclusion: Salvage arthrodesis after failed TAR had a solid arthrodesis rate of 90% at first attempt, but similar to revision TAR, less than 50% of the patients were satisfied and the functional scores were low. Until studies show true benefit of revision TAR over SA, we favor SA for failed TAR. Level of Evidence: Level IV, retrospective case series.

Survival Analysis of the Single- and Double-Coated STAR Ankle up to 20 Years Long-Term Follow-up of 324 Cases From the Swedish Ankle Registry

Background: The Scandinavian Total Ankle Replacement (STAR) has been used widely in Europe and more recently in the United States. We studied the results of the single-coated and the double-coated STAR with long-term follow-up. Methods: All STARs (n = 324) used in Sweden (first implanted in 1993) were included. Prosthetic survival was estimated according to Kaplan-Meier. Results: The 14-year survival of the single-coated STAR was 0.47 (95% confidence interval [CI], 0.38-0.66), and the 12-year survival of the double-coated STAR was 0.64 (95% CI, 0.57-0.71). Women younger than 60 years with osteoarthritis had a statistically significantly higher risk of revision than men and than patients with other diagnoses. Conclusion: The long-term results of the STAR prosthesis are not encouraging. The results seem to deteriorate by time. Level of Evidence: Level IV, retrospective case series.

Trabecular metal tibial knee component still stable at 10 years : An RSA study of 33 patients less than 60 years of age

Background and purpose — Total knee replacement (TKR) in younger patients using cemented components has shown inferior results, mainly due to aseptic loosening. Excellent clinical results have been reported with components made of trabecular metal (TM). In a previous report, we have shown stabilization of the TM tibial implants for up to 5 years. In this study, we compared the clinical and RSA results of these uncemented implants with those of cemented implants. Patients and methods — 41 patients (47 knees) aged ≤ 60 years underwent TKR. 22 patients (26 knees) received an uncemented monoblock cruciate-retaining (CR) tibial component (TM) and 19 patients (21 knees) received a cemented NexGen Option CR tibial component. Follow-up examination was done at 10 years, and 16 patients (19 knees) with TM tibial components and 17 patients (18 knees) with cemented tibial components remained for analysis. Results — 1 of 19 TM implants was revised for infection, 2 of 18 cemented components were revised for knee instability, and no revisions were done for loosening. Both types of tibial components migrated in the first 3 months, the TM group to a greater extent than the cemented group. After 3 months, both groups were stable during the next 10 years. Interpretation — The patterns of migration for uncemented TM implants and cemented tibial implants over the first 10 years indicate that they have a good long-term prognosis regarding fixation

Total ankle replacement and contralateral ankle arthrodesis in 16 patients from the Swedish Ankle Registry: Self-reported function and satisfaction

BACKGROUND Both total ankle replacement (TAR) and ankle arthrodesis do show some problems in long-term studies. To choose either of these surgical options is a delicate task. There are no randomized studies reported in the literature and no previous studies in which patients constitute the own controls. METHODS Patients with a TAR and a contralateral ankle arthrodesis were identified in the Swedish Ankle Register. A self-reported foot and ankle specific questionnaire (SEFAS) was sent to these patients who also were asked to report their grade of satisfaction from 1 to 5. RESULTS The median SEFAS score was 32 (16-44) for the prostheses and 27 (14-47) for the arthrodeses. The median satisfaction score was 2 (1-4) for the prostheses and 2 (1-5) for the arthrodeses. There were no statistically significant difference between the prosthetic side and the fused side regarding these scores. CONCLUSION Patients who had undergone ankle arthrodesis on one side and had the contralateral ankle replaced, were equally satisfied with both procedures.