• Patient Rated Wrist Evaluation (PRWE) at baseline, 6 weeks, 3, 6 and 12 months post-operatively. [ Time Frame: Subjects are followed for 12 months post-op. ] [ Designated as safety issue: No ]
  

• Wrist range of motion, grip strength, radiographs and pain Visual Analog Scale [ Time Frame: Baseline, 6 weeks, 3,6 and 12 months. ] [ Designated as safety issue: No ]
  

Ulnocarpal abutment syndrome (UAS) (also known as ulnar impaction syndrome, ulnocarpal impingement,ulnar carpal loading) is a common cause of ulnar sided wrist pain.

UAS results from increased loading of the ulnocarpal articulation and is usually associated with a positive ulnar variance. The increased loading of the joint can lead to degeneration and perforation of the Triangular fibrocartilage (TFC). Chondromalacic changes develop on the opposing surfaces of the lunate and triquetrum distally and the ulnar head proximally. A disruption of the lunotriquetral ligament may following with ensuing LT arthritis.

Treatment of UAS involves decompression of the pressure and impingement, or abutment of the ulnocarpal articulation. Debridement of triangular fibrocartilage complex (TFCC) tears alone in the patient with UAS may have a failure rate of as much as 25% to 30%. Good results have been reported with combined arthroscopic TFCC debridement and distal ulnar resection. 69% excellent and 32% good results have been reported with an open limited distal ulnar resection in patients with a TFCC tear and positive ulnar variance. Similar results have been reported with both ulnar shortening osteotomy and open wafer distal ulnar resections in the UAS patient. Because these treatment choices appear to yield similar relief of symptoms, determination of the optimal treatment protocol remains a point of debate.

The literature contains retrospective data comparing open wafer procedure with ulnar shortening osteotomies for the treatment of UAS. Likewise, the literature comparing arthroscopic wafer and ulnar shortening osteotomy is retrospective. However, there are, to date, no randomized prospective clinical trials comparing these types of surgery. Both types of surgery are widely accepted and the optimal treatment remains under debate. It is unclear how the techniques compare in terms of efficacy of elimination of symptoms of UAS and also in terms of relative complication rate.