As the English-language literature on prosthetic elbow arthroplasty contains only two comparative studies of implants in contemporary use, to our knowledge, comparisons of prosthetic performance is difficult. An improved knowledge of comparative outcomes would be valuable in guiding implant selection.
We identified three groups of consecutive patients who had undergone prosthetic elbow arthroplasty with the Souter-Strathclyde, Kudo, or Coonrad-Morrey implant for the treatment of rheumatoid arthritis. There were thirty-three elbows in each group. All procedures were done by or under the supervision of one surgeon. Surviving patients in whom the elbow had not been revised were followed for a mean of sixty-one months after treatment with the Souter-Strathclyde implant, sixty-seven months after treatment with the Kudo implant, and sixty-eight months after treatment with the Coonrad-Morrey implant. Clinical function was assessed on the basis of pain relief and the range of flexion. Survivorship was assessed with use of a life-table method, with revision surgery and radiographic signs of loosening as the end points.
The groups were comparable in terms of age, sex, and mean duration of follow-up. All three implant procedures relieved pain. Sustained improvement in the range of flexion was comparable among the three groups, with no implant procedure dramatically changing the fixed flexion deformity and all three improving maximum flexion. Revision surgery was needed because of infection, dislocation, and aseptic loosening. Survival of the Coonrad-Morrey implant was better than that of the other two implants. The five-year survival rates, with revision and radiographic signs of loosening as the end points, were 85% and 81% for the Souter-Strathclyde implant, 93% and 82% for the Kudo implant, and 90% and 86% for the Coonrad-Morrey implant. While radiographic evidence of loosening of the Coonrad-Morrey implants was less common, we noted focal osteolysis adjacent to 16% of these ulnar components and half of these cases progressed to frank loosening.
The clinical function of these implants was similar in terms of pain relief and range of motion. We believe that component linkage with the Coonrad-Morrey implant prevents dislocation without increasing the risk of loosening.