Clinical outcome and survival rate of the Herbert ulnar head prosthesis for reconstruction of the distal radioulnar joint depending on co-morbidity and different indications.

Abstract

Ulnar head prostheses have been developed to restore the integrity of the DRUJ and relieve pain. This study aims to evaluate the long-term outcome of the clinical and radiographic results as well as the survival rate of the Herbert ulnar head prosthesis (UHP) depending on co-morbidity and different indications. The Herbert ulnar head prosthesis was implanted in 62 patients. In the majority of the patients, the indication was given due to pain during forearm rotation. This was on account of painful instability of the distal ulna following Bowers (59.7%) or Kapandji procedure (16.1%), Darrach procedure (8.1%) or painful post-traumatic (12.9%) or primary osteoarthritis (3.2%). Of the 62 patients, 34 were men and 28 women. The mean age at the time of operation was 49years (range 18-84years). A clinical and radiographic evaluation was performed including pain scale, range of motion, grip strength and the DASH and modified Mayo wrist scores. The average follow-up was 84.5months (range 8-206months), and statistically significant reduction of pain was observed (p < 0.05). The range of motion of pro- and supination improved slightly, but not significantly, whereas the DASH score improved significantly from 56 to 43 (p < 0.05). Patients without an arthrodesis achieved better results in the DASH and in the modified Mayo wrist score. In 39 cases, a small amount of bone resorption was seen at the collar of the prosthesis in the follow-up radiographs. A revision surgery was necessary in 14 patients. The Kaplan-Meier survival rate after 15years was 90.3%. The long-term results of the UHP are encouraging regardless of different indications with a survival rate of more than 90% 7years following surgery, high patient satisfaction and good clinical and radiographic results. IV.