Outcomes of Revision Unlinked Total Elbow Arthroplasty for Rheumatoid Elbow

Background: Although unlinked total elbow arthroplasty (TEA) is a treatment option for end-stage rheumatoid arthritis (RA) of the elbow, its long-term outcomes were inferior. Moreover, revision TEA could be technically challenging. The unlinked TEA procedure comprises the ease of implant removal at revision and advantage of bone preservation. This study evaluated the clinical outcomes in patients who underwent revision TEA using primary unlinked TEA for rheumatoid elbows. It also aimed to determine whether selecting the unlinked prosthesis for the primary TEA would make revision more accessible and successful. Methods: We retrospectively reviewed data of 13 consecutive patients (14 elbows) who underwent revision TEAs for implant failure due to different aetiologies, excluding septic loosening. Three different unlinked TEA implants were used: the Kudo type-5 with all-polyethylene (AP) ulnar component, Kudo type-5 with metal-backed (MB) ulnar component and K-Now TEA. We evaluated the patients' pre- and postoperative outcomes, including the range of motion, pain score and Mayo Elbow Performance Index (MEPI). Results: Among the 14 elbows, 11 were revised using the Kudo type-5 ulnar component (nine and two with AP and MB ulnar component, respectively), and three using the K-Now. We found that each model of TEA had different tendencies to indication for revision surgery. Three more resulted in further failure. The clinical outcomes were assessed in the 11 surviving elbows. Eight of the 11 elbows showed no pain at the final follow-up. However, the remaining three showed only mild pain. The MEPI revealed that seven cases were excellent, two were good and two were fair. Conclusions: The mode of implant failure was largely dependent on the implant design. Furthermore, partial revision with the same implant design was sufficient in managing implant failure in the early phase. However, conversion from unlinked to linked design could be recommended in patients with progressive failure or instability. Level of Evidence: Level IV (Therapeutic).