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

Bilateral Arthrodesis of the Ankle Joint : Self-Reported Outcomes in 35 Patients From the Swedish Ankle Registry

Bilateral ankle arthrodesis is seldom performed, and results concerning the outcome and satisfaction can only sparsely be found in published studies. We analyzed the data from 35 patients who had undergone bilateral ankle arthrodesis in the Swedish Ankle Registry using patient-reported generic and region-specific outcome measures. Of 36 talocrural arthrodeses and 34 tibio-talar-calcaneal arthrodeses, 6 ankles (9%) had undergone repeat arthrodesis because of nonunion. After a mean follow-up period of 47 ± 5 (range 12 to 194) months, the mean scores were as follows: self-reported foot and ankle score, 33 ± 10 (range 4 to 48); the EuroQol Group's EQ-5D™ score, 0.67 ± 0.28 (range −0.11 to 1), the EuroQol Group's visual analog scale score, 70 ± 19 (range 20 to 95), 36-item Short Form Health Survey (SF-36) physical domain, 39 ± 11 (range 16 to 58); and SF-36 mental domain, 54 ± 14 (range 17 to 71). Patients with rheumatoid arthritis seemed to have similar self-reported foot and ankle scores but possibly lower EQ-5D™ and SF-36 scores. Those with talocrural arthrodeses scored higher than did those with tibio-talar-calcaneal arthrodeses on the EQ5D™ and SF-36 questionnaires (p = .03 and p = .04). In 64 of 70 ankles (91%), the patients were satisfied or very satisfied with the outcome. In conclusion, we consider bilateral ankle arthrodesis to be a reasonable treatment for symptomatic hindfoot arthritis, with high postoperative mid-term satisfaction and satisfactory scores on the patient-reported generic and region-specific outcome measures, when no other treatment option is available

Use of a trabecular metal implant in ankle arthrodesis after failed total ankle replacement: A short-term follow-up of 13 patients

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

Total knee arthroplasty : aspects on improved fixation in the younger patient

The results of total knee arthroplasty are inferior in younger patients. The challenge today is therefore to develop designs and concepts that will last at least 25 years. This thesis has evaluated the fixation to bone of modern designs of knee prostheses uring RSA analysis. Coating implant surfaces with hydroxy-apatite have proven to enhance fixation to bone. Addition of screws for fixation of the tibial component enhances the fixation, but has negative side effects such as osteolysis around the screws, in turn leading to a higher risk of component loosening. The magnitude and pattern of migration was studied in a randomized study of uncemented tibial implants coated with hydroxy-apatite with and without additional screw fixation in patients younger than 65 years. The uncemented implants migrated initially more than the cemented implants that constituted the control group. Both uncemented groups stabilized at 3 monthes with no further migration, while the cemented implants showed a continuous migration up to the 2 year follow-up, indicating continuous bone resorption at the implant-bone interface, a fact that might lead to an increased risk of late implant loosening. This may not be a problem in older patients, but may have consequences for long-term fixation in younger patients. There was no difference between the two uncemented groups indicating that screws do not improve fixation. Hydroxy-apatite coated knee implants might be well suited for younger patients. Mobile bearing total knee arthroplasty theoretically uncouples the forces at the implant-bone interface, thus improving fixation of the implant to bone. The magnitude and pattern of migration of a cemented mobile bearing knee arthroplasty and a fixed bearing total knee arthroplasty was compared in a randomized study. The results showed that mobile bearings did not improve fixation. Trabecular metal, a new material recently introduced for total knee arthroplasty, has several theoretical advantages. Trabecular metal tibial implants were evaluated in a randomized study in patients younger than 60 years. The implants displayed the typical migration pattern for uncemented implants with greater migration initially followed by early stabilization. The majority of the trabecular metal implants subsided into the bone with no lift-off. Lift-off has the potential of exposing the interface to joint fluid with the potential risk of bone resorption and late loosening, and is commonly seen in metal-backed implants. The finding of absence of lift-off is regarded beneficial for uncemented fixation. Trabecular metal tibial implants might be suited for younger patients. The optimal mode of fixation of the femoral component is yet to be established. Comparing cemented femoral components with uncemented femoral components in a randomized study in patients younger than 60 years revealed no differences of the magnitude or the pattern of migration. Uncemented femoral component seems equally as good as cemented components in younger patients

Response to "Letter Regarding: 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"

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

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.

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