A new total distal radioulnar joint prosthesis: functional outcome

Abstract

Purpose: To present the evolution of design and the short-term functional outcome of our distal radioulnar joint (DRUJ) prosthesis. This total DRUJ prosthesis differs from others in that it consists of 2 parts and attains bony fixation by its hydroxyapatite coating.

Methods: Nineteen patients received a DRUJ prosthesis after a failed Darrach procedure (n = 10), Sauvé-Kapandji procedure (n = 7), trauma (n = 1), or DRUJ synovitis (n = 1). Indications for the placement were decreased grip, decreased forearm motion, and pain due to ulnar impingement syndrome and instability of the distal ulna. Seven prostheses were removed, 5 due to loosening, 1 due to continuing pain, and 1 at the request of the patient. The 5 prostheses that loosened were an intermediate prototype no longer in use. In 12 remaining cases, range of motion, grip strength, and pinch strength were measured, and patients completed the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire. Pain was assessed with the visual analog scale (range, 0-10). A paired t-test was performed to assess the significance of the difference between preoperative and postoperative measurements.

Results: Statistically significant improvements were seen in forearm pronation, from an average of 79° to 88°; grip strength, from an average of 10 kg to an average of 16 kg; and visual analog scale score, decreased from a mean of 5.3 to a mean of 3.5. The distal ulna was clinically stable in all 12 patients who retained the prosthesis.

Conclusions: The intermediate prototype had a high failure rate, 5 out of 5. The early results for the current prosthesis prototype show clinical improvement. Based on these results, we conclude that this prosthesis offers a new treatment option for ulnar instability after distal ulnar resection.

Type of study/level of evidence: Therapeutic IV.