This retrospective review included 31 wrists in 29 patients with idiopathic ulnar impaction syndrome from Seoul, South Korea that were treated with an ulnar shortening osteotomy after failing conservative measures. Inclusion criteria included ulnar wrist pain that increased with an impaction maneuver with positive ulnar variance without a history of trauma or congenital malformation of the wrist. The average preoperative ulnar variance was +4.6 mm (range, 2 to 7.5 mm) which was improved to an average of –0.7 mm (range, -4 to +1 mm). At an average follow-up of 32 months (range, 18-60 months), the modified Gartland and Werley score improved from an average of 70 to 94. Preoperative dorsal subluxation of the ulna noted on the lateral radiograph was reduced with ulnar shortening in nine wrists. In addition, seven patients with preoperative cystic changes of the carpus were not evident by one to two years after the operation. All osteotomies were performed transversely and fixed with a six or seven hole 3.5 mm compression plate (24 patients) or a one-third tubular plate (7 patients) in smaller individuals. Nine patients with distal radioulnar joint problems including tenderness, limitation of motion or apparent dorsal prominence significantly improved. This included increased forearm rotation from an average of 122 degrees to148 degrees postoperatively. Union of the osteotomy was achieved at an average of 11.5 weeks (range, 8 to 16 weeks) in all patients. There were no nonunions or infections, although two patients developed a postoperative reflex sympathetic dystrophy and ended with a score of fair or poor. Seventeen patients underwent concomitant arthroscopy for associated TFCC pathology and were all found to have degenerative changes of the TFCC, although only 5 had a full central perforation. Each of these patients exhibited chondromalacia of the lunate of varying degrees with three patients undergoing a microfracture technique for full thickness cartilage lesions on the lunate.
This study confirms the benefits of ulnar shortening to treat idiopathic ulnar impaction syndrome with remarkably good results and limited complications. In addition, preoperative cystic changes of the carpus and even apparent dorsal subluxation of the ulna was reduced. Further comparative studies between ulnar shortening osteotomy and distal ulnar wafer excision may be beneficial.
J Bone Joint Surgery