Long-term results after triple arthrodesis: Influence of alignment on ankle osteoarthritis and clinical outcome.

BACKGROUND: Pain, deformity and instability are the main reasons for fusion of the tarsal joints, a triple arthrodesis. The short and midterm results show that mobility, function and satisfaction increase postoperatively. However, osteoarthritis (OA) of the adjacent ankle joint is described as a long-term complication. Alignment of the foot could be an influencing factor. The aim of this study was to examine whether malalignment after triple arthrodesis leads to a higher grade of OA at long-term follow-up. METHODS: Between 1991 and 2002, 81 patients underwent a triple arthrodesis. Preoperatively, postoperatively, 3, 7.5 and 15 years after surgery, dorsoplantar (DP) and lateral X-rays were taken and used to evaluate the degree of OA and the geometry of the foot. The degree of OA was estimated using the Kellgren and Lawrence score. The geometry of the foot was assessed using Meary's angle; a Meary's angle exceeding 15° in DP and/or greater than -5 to 5° from the lateral view was defined as malalignment. In addition to the radiological evaluation, clinical scores (FFI and AOFAS) were recorded. RESULTS: Thirty-five patients (40 feet) were available for analysis 15 years after surgery. In 19 cases there was an increase in ankle OA following the operation. Eight feet showed malalignment on the lateral view and 28 on the DP view. There was no difference in both an increase of ankle OA or clinical outcome between correct aligned feet and feet classified as malaligned. Thirty-three patients with 38 treated feet stated that they would decide to undergo the treatment again. Two patients would not want to undergo the same surgery again. The patients were satisfied with the result of surgery, clinical scores improved after surgery and remained stable in the long-term. CONCLUSIONS: Triple arthrodesis is a salvage procedure in patients with a painful and deformed hindfoot and results in a clinically beneficial outcome, even 15 years after surgery. The present study did not show that malalignment after triple arthrodesis results in a higher grade of OA of the ankle joint in the long-term. The cause of the aggravation of OA is still not fully understood and needs further research. Nevertheless, clinical results are satisfying 15 years postoperatively.

Does osteoarthritis of the ankle joint progress after triple arthrodesis? A midterm prospective outcome study.

BACKGROUND: Debate exists regarding the effect of triple fusion on the development of osteoarthritis (OA) of the ankle joint. The midterm outcome after triple arthrodesis and the prevalence of OA following triple arthrodesis are reported in this study. The role of alignment in the development of OA was investigated. METHODS: Seventy five patients (87 feet) were evaluated in 2003 and of these, 48 patients (55 feet) were available for second evaluation in 2008. X-rays of the ankles and feet were made prior to surgery, in 2003 and in 2008, and the level of osteoarthritis (OA) was graded with the Kellgren and Lawrence score. Of all postoperative X-rays, the AP and lateral talo first metatarsal angle X-rays were compared. Also, standardized digital photos were made to assess the geometry/alignment. The Foot Function Index (FFI) and the American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score were completed. In order to investigate the role of the underlying alignment on the aggravation of ankle osteoarthritis, patients were divided into a 'varus' and a 'valgus' group based on the indication for surgery. RESULTS: The outcome scores (AOFAS and FFI) after triple arthrodesis remained stable in the present 7.5-year follow-up study. An important increase of OA of the ankle was not established, 58% of the patients showed no aggravation, 31% one-grade and 2% two-grade increase of OA. A trend was found (P=.063) towards aggravation of OA of the ankle in patients of the varus group with the highest medial arches (persistent cavovarus deformity). CONCLUSION: This study reports minor, not statistically significant, changes of the ankle joint following triple arthrodesis after 7.5 years. Clinical outcome remained stable in time. Clinical relevance It seems that triple arthrodesis as such does not lead to major osteoarthritis of the ankle, given that adequate alignment of the hindfoot is achieved. LEVEL OF EVIDENCE: Level II, retrospective study.