The surgical treatment of periprosthetic elbow fractures around the ulnar stem following semiconstrained total elbow arthroplasty.

BACKGROUND

Limited information exists related to the treatment of periprosthetic fractures of the ulna after semiconstrained elbow arthroplasty. Our goals were to characterize the clinical and radiographic features of periprosthetic fractures around the stem of a loose ulnar component and to determine the outcomes after surgical treatment.

METHODS

Between 1980 and 2008, thirty consecutive periprosthetic fractures around the ulnar stem were treated surgically at our institution. Eighteen fractures occurred after primary arthroplasty, and twelve occurred after revision arthroplasty. The mean time between the index arthroplasty and the fracture was eight years. All ulnar components were loose. Ulnar bone loss was moderate in fourteen elbows and severe in sixteen. Surgical reconstruction included revision of the ulnar component in all cases. Fracture fixation was achieved with a longer stemmed implant only in two elbows. Strut allografts were used in twenty elbows, with additional impaction graft augmentation in eight of them. Three additional elbows were revised with impaction grafting alone, and five were reconstructed with an allograft ulnar prosthetic composite. Seven patients were lost to follow-up, one died, and one was managed with conversion to a resection arthroplasty following a deep infection. The remaining twenty-one patients were followed for a mean of 4.9 ± 2.6 years.

RESULTS

At the time of the most recent follow-up, eighteen patients reported no pain or mild pain and three patients reported moderate pain. The mean arc of elbow flexion and extension was 112°. The Mayo Elbow Performance Score was 82 points (with fifteen good or excellent results and six fair or poor results). Fracture-healing was achieved in the twenty-one followed patients. Complications included three deep infections, one superficial infection, one case of ulnar component loosening, and one case of transient dysfunction of both the median and radial nerves.

CONCLUSIONS

Periprosthetic ulnar fractures around the stem of a loose ulnar component after total elbow arthroplasty usually combine implant loosening and severe bone loss. Revision of the ulnar component may require additional strut allografts, allograft-prosthetic composites, or impaction grafting. Satisfactory outcomes were seen after the majority of revisions; however, deep infections and component loosening continue to be serious complications.