Outcomes following Distal Radioulnar Joint Arthroplasty in the Setting of Total or Partial Wrist Fusion.

 To evaluate the functional outcome and complications following primary ulnar head or total distal radial ulnar joint (DRUJ) arthroplasty in patients who have a partial or total wrist fusion.  We conducted a retrospective review of 33 primary DRUJ implants in 31 patients who had a partial or total wrist fusion. Follow-up time averaged 67 months. There were 11 partial and 22 total wrist fusions with 22 ulnar head prosthesis and 11 total DRUJ implants. The mean age of the patients was 49 years. Eighty-one percent had previous surgeries with an average number of 4.6 previous wrist procedures. Pre- and postoperative pain levels were recorded. Mayo Wrist Scores were calculated. Grip strength, range of motion (ROM), and post-operative complications were noted.  The pain scores improved in 67% of the patients. The Mayo Wrist Score improved significantly from a mean of 39 preoperatively to 51 postoperatively. The grip strength and pro-supination remained stable. The wrist ROM also remained stable in the patients with partial wrist fusions. During the follow-up period, 10 (30%) of the DRUJ implants were explanted, with a trend toward higher explantation rates in total wrist fusions with one in the partial fusion group and nine in the total wrist fusion group. Four of the explantations happened in the first postoperative year. Nineteen (61%) of the patients required a second surgery for a DRUJ implant-related complication; this rate was similar between the partial and total fusion groups.  DRUJ replacement resulted in improved pain scores and Mayo wrist scores in the majority of patients; however, the combination of primary DRUJ arthroplasty and total wrist fusion was associated with high complication rates. Surgeons should be aware of the high complication rate seen with DRUJ arthroplasty when combined with total wrist fusion.