Semiconstrained primary and revision total elbow arthroplasty with use of the Coonrad-Morrey prosthesis

Background: Semiconstrained total elbow prostheses are used routinely by many surgeons to treat a variety of severe elbow disorders. Our objective was to review the results of primary and revision total elbow arthroplasty with use of the Coonrad-Morrey prosthesis. The selected use of this semiconstrained implant in patients with instability and poor bone stock was hypothesized to provide inferior results compared with those in the published reports. Methods: The results of sixty-seven semiconstrained total elbow arthroplasties that were performed in fifty-six patients between 1990 and 2003 were evaluated. Thirty-seven elbows had a primary arthroplasty and were followed for a mean of eighty-six months, and thirty elbows had a revision arthroplasty and were followed for a mean of sixty-eight months. Mayo elbow performance scores and radiographic analyses were used to assess the clinical results. Results: In the primary arthroplasty group, the average flexion improved from 116 degrees to 1350; average extension, from -40 degrees to -33 degrees; average pronation, from 600 to 810; and average supination, from 600 to 69 degrees. The improvements in flexion and pronation were significant (p < 0.001 for both). Preoperatively, twenty-five (74%) of thirty-four elbows with data available had moderate or severe pain, whereas only four (11%) had pain postoperatively. The average postoperative Mayo score (and standard deviation) was 84 +/- 16. Eleven of the thirty-seven primary replacements failed, and the five-year survival rate was 72%. In the revision arthroplasty group, average flexion improved from 1240 to 1310; average extension, from -32 degrees to -22 degrees; average pronation, from 66 degrees to 750; and average supination, from 64 degrees to 76 degrees; the improvement in supination was significant (p < 0.05). Preoperatively, eighteen (64%) of the twenty-eight elbows with data available had moderate or severe pain, while only five (17%) had pain postoperatively. The average postoperative Mayo score was 85 16. Eleven of the thirty revision replacements failed, and the five-year survival rate was 64%. Conclusions: A Coonrad-Morrey semiconstrained total elbow arthroplasty provides excellent pain relief and good functional return in patients with severe destructive arthropathy. The higher prevalence of failure in this cohort compared with series reported elsewhere is likely due to adverse patient selection as this implant was reserved for more complex arthroplasties with severe bone loss and ligamentous laxity.