TOTAL ANKLE ARTHROPLASTY: 58 CASES

Abstract

Purpose of the study: The place for total ankle arthroplasty versus fusion remains a subject of debate for the treatment of painful stiff ankles.

Material and methods: This series included 58 total ankle arthroplasies performed in 56 patients between 1991 and 2003. Mean paient age was 52 years (range 27–84). The underlying cause was multiple trauma (n=27), rheumatoid arthritis (n=17), chronic instability (n=11), hemophilia (n=2), primary disease (n=1). Four implants were used: New Jersey (n=22), Albatros (n=4), Star (n=10), AES (n=22). Associated procedures were: lengthening of the Achilles tendon or vastus (n=28), lateral ligamentoplasty (n=6), fibular osteotomy (n=2), medial ligamentoplasty (n=1), calcaneal osteotomy (n=3), double arthrodesis (n=1). The patients wore a plaster cast for 21 to 40 days.

Results: Eight patients were removed from the analysis: death (n=4), foreign residence (n=1, 3 follow-up shorter than one year (n=3). The analysis retained 50 total ankle arthroplasties in 48 patients reviewed with a mean 49 months follow-up (range 1–12 years). Reasons for surgery were: trauma (n=25), rheumatoid disease (n=12), instability (n=10), hemophilia (n=2), primary (n=1). Implants were: New Jersey (n=17), AES (n=19), Star (n=9), Albatros (n=3). Complications were: intra-operative medial malleolar fractures which were pinned (n=8), immediately revised radiological instability (n=2), wound dehiscence treated with a flap (n=1), secondary fusion (n=4). There were no cases of infection. There were six failures (12%) leading to implant removal for loosening (n=3), pain (n=2), instability (n=1) and revision arthrodesis (n=4) or new arthroplasty (n=2). The 44 remaining cases were analyzed: AOFAS score improved from 40/100 to 73/100 at last follow-up. Joint motion was 24° preoperatively and 20.5° postoperatively (dorsal flexion −1° to +6°, plantar flexion 25° to 14.5°).

Radiographically five prostheses were unstable with potential loosening (3 tibial and 2 talar components), one presented varus misalignment, and the others were considered correct. Moderate to severe intra-articular osteophytes were noted in 11 ankles. Three presented an undetermined defect image in the tibia.

Discussion: Indications for total ankle arthroplasty are exceptional and different from total prostheses for the knee or hip joints. Patients are young subjects with stiff, misaligned, unstable ankles, generally resulting from traumatic injury. Surgery is a challenge and requires several complementary procedures. Failure rate is higher than for the knee or the hip but mid-term results are encouraging. Further follow-up is needed for long-term confirmation.