Extensor Mechanism Reconstruction with Achilles Tendon Allograft in TKA: Results of an Abbreviate Rehabilitation Protocol

Various treatment alternatives address extensor mechanism failure after total knee arthroplasty. We present the results of a protocol utilizing Achilles tendon allograft followed by an abbreviated immobilization program to treat extensor mechanism disruptions after TKA in 29 knees (27 patients). Failed reconstruction was defined as mechanical allograft failure requiring re-intervention, extension lag >30°, recurrent falls, regression to a lower ambulatory status, and revision due to infection. With mean follow-up of 3.5 years, seventeen cases (58.6%) had satisfactory results, eleven cases (37.9%) were considered failures, and one case was lost to follow-up. Among failures, eight (27.5%) underwent reoperation with four (13.8%) due to late infections. Our observational data suggest that 1) a shortened immobilization protocol yields less favorable results than expected, and 2) continuous monitoring of patients who had allograft reconstruction for possible development of late infection is recommended.