Total ankle replacement improves pain for young RA patients

British researchers found a 30-point increase in AFOAS scores following implantation of ankle prostheses.

Total ankle replacement may provide substantial pain relief and improve American Orthopaedic Foot and Ankle Society scores in young patients with polyarticular rheumatoid arthritis.

In a study of 24 procedures, British researchers found a 30-point increase in American Orthopaedic Foot and Ankle Society (AFOAS) scores following implantation. Patients were “pleased with the outcome” of 21 of the replacements, said researcher Peter L. R. Wood, FRCS. “We consider total ankle replacement as an alternative to fusion for a young patient who has polyarticular rheumatoid disease,” Wood said during his presentation at the British Orthopaedic Association Annual Congress in Birmingham, U.K.

Wood implanted 20 Scandinavian Total Ankle Replacements and four Buechel-Pappas replacements in 19 patients. Patients included in the research were 18 to 40 years old. Twelve patients displayed neutral alignment, nine were valgus and three had varus deformities. “All had associated hindfoot disease,” Wood wrote in his abstract. The researchers selected the cohort from 500 ankle replacements and followed them for an average 62 months.

Three failures converted to fusion

The replacements proved beneficial for the majority of patients. “Twenty-one replacements have good pain relief and function,” Wood noted in the abstract. Three replacements failed and were converted to fusion and only one patient displayed severe valgus deformity. “I now appreciate that this is a contraindication to replacement,” said Wood, who is an orthopedic consultant for Wrightington Hospital UK. “One of them failed for aseptic subsidence of the talar component and one has persistant pain for no obvious reason,” he said.

Patients showed marked improvements in pain relief on their AOFAS scores. AOFAS function scores were low and increased 14 points because of the severity of polyarticular disease, Wood said. “[The] problem with that type of scoring is that it does not show that four patients became free from the wheel chair because of their joint replacements,” he noted.

Wood cautions that the procedure should not be applied in all young rheumatoid patients. “For patients who have severe valgus or varus deformity or a very stiff ankle, then fusion obviously is still going to be the appropriate treatment,” he said.

Wood no longer uses the Scandinavian Total Ankle Replacement prosthesis because better prostheses are being developed, he added.

These preoperative and five-year postoperative radiographs illustrate a patient who used a wheelchair prior to total ankle replacfement. After the procedure, the patient can walk one mile.

COURTESY: PETER L.R. WOOD

For more information:
Wood PLR. Total ankle replacement in the young rheumatoid patient. Presented at the British Orthopaedic Association Annual Congress. Sept. 20-23, 2005. Birmingham, England.