This is a retrospective review of 10 patients that required revision of the ulnar component of a total elbow arthroplasty felt by the authors to be related to impingement between the anterior flange of the humeral component on either cement on the ulnar component, osteophyte of the ulna or soft tissue impingement resulting in pistoning of the ulnar component. The average age was 57 years (range, 32-76 years) with mean interval from primary arthroplasty to the revision was 50 months (range, 17-96 months). Preoperative findings revealed three patients exhibiting pistoning by axially loading the ulnar stem with manual compression and distraction and three patients with clunking noted at the extremes of flexion and extension. In nine patients, the prosthesis was loose in the cement. Each patient had a Coonrad-Moorey total elbow prosthesis with a polymethylmethacrylate precoat ulnar component. This precoat was discontinued in 2001 because of previous reports of debonding of the polymethylmethacrylate precoat from the stem.
Although the precoat methacrylate on the ulnar component may have been a significant risk factor for the development of this early loosening of the ulnar component from impingement and pistoning, it should be recognized as a potential source of failure of all linked elbow arthroplasties. The authors indicate that steps to include at the time of implantation to prevent this mode of failure would include trimming away excess anterior osteophytes or a prominent coronoid or cement after checking for anterior impingement during a trial range of motion. The authors report routinely trimming the tip of the coronoid down to the level of the brachialis insertion as a prophylactic measure to prevent anterior impingement. The authors also recommend avoiding passive hyperflexion past 135 degrees.
Elbow, Arthroplasty, Precoat, Loosening, Pistoning, Component
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J. Bone and Joint Surgery