Functional outcome comparison of semiconstrained and unconstrained total elbow arthroplasties

Twenty-six patients, each of whom had undergone either a semiconstrained (l inked) or an unconstrained (unlinked) total elbow arthroplasty, were examin ed specifically to evaluate the restoration of function with respect to act ivities of daily living. The functional outcomes of these 2 groups were the n compared to identify any significant differences. All of the unlinked/unc onstrained prostheses were Ewald total elbow arthroplasties; the linked/sem iconstrained prostheses, all of which were performed by a single surgeon, w ere Mayo-Coonrad prostheses. Follow-up radiographs, token to rule out loose ning or failure of the prosthesis as a cause for functional deficits, were available fbr review for 25 elbows. There were Id elbows in 13 patients who had semiconstrained prostheses and 12 elbows in 10 patients who had uncons trained total prostheses. Average age at the time of elbow replacement surg ery was 62.8 years (range, 47-75 years) for the semiconstrained group and 6 3.1 years (range, 54-74 years) For the unconstrained group. The semiconstra ined group consisted of 8 female and 6 merle elbows; the unconstrained grou p consisted of 10 female and 2 male elbows. Follow-up averaged 35.5 months (range, 24-73 months) in the semiconstrained group and 73 months (range, 27 -110 months) in the unconstrained group. Twenty-two operations were perform ed for rheumatoid arthritis, 3 for posttraumatic humeral nonunion, and I Fo r posttraumatic degenerative arthritis. Two elbows required revision, one ( in the semiconstrained group) for aseptic loosening and the other (in the u nconstrained group) for metal synovitis and pain from a chronically disloca ted prosthesis; both of these elbows were considered failures and excluded from the functional comparison. No significant differences in functional pe rformance were found, and no elbows demonstrated progressive radiolucencies suggestive of loosening. With the exception of I patient (in addition to t he patients who had revisions) with a dislocated unconstrained prosthesis, all patients were satisfied with the procedure. It appears that when it is properly performed, total elbow arthroplasty with either type of prosthesis yields satisfactory functional results.