This is a retrospective review of 37 patients who were treated using 46 primary Pritchard ERS arthoplasties between 1983-1992. This is an unlinked prosthesis with a separate radial head component. Unfortunately, the 10-year survival of the implant was only 54%. The authors found that 32 implants (70%) failed in an average of 83 months. The main reasons for failure were instability, wear, and loosening.
Interestingly, immediate postoperative radiographs showed ulnohumeral malpositioning in either varus or valgus in 19 elbows which directly correlated to subsequent failure. In fact, 12 of the 19 radiographs with frontal plane malpositioning went on to early loosening and failure. The authors go on to report that the most important reason for failure of the implant was related to initial incongruity of the ulnohumeral articulation at the time of insertion. This confirms the importance of correct alignment and soft-tissue balancing regardless of the use of a radial head component. This implant thus has obvious design limitations. The use of unlinked elbow arthroplasty is more popular in Europe and it is not currently used on a widespread basis in the United States.