Ulnar shortening with the ulna osteotomy locking plate.

OBJECTIVE: Ulnar shortening for ulnocarpal unloading using a new device enabling parallel osteotomy, rotation-secured compressive shortening, lag screw placement and hybrid stabilization combined in a solely locking plate construct.

INDICATIONS: Idiopathic ulnar impaction syndrome. Posttraumatic radial shortening without major tilting of the radius in the sagittal or frontal plane, rotation deformity and/or translation of the distal fragment.

CONTRAINDICATIONS: Advanced arthritis of the distal radioulnar joint (DRUJ), DRUJ type III according to Tolat, malunion of the distal radius with major tilting of the radius in the sagittal or frontal plane, rotation deformity and/or translation of the distal fragment.

SURGICAL TECHNIQUE: Mounting of the UOL plate system on the palmar surface of the ulna using standard ulnopalmar exposure. Two parallel 45° osteotomies are performed using an osteotomy guide followed by rotation secured shortening and compression. Stabilization is gained by inserting an interfragmentary lag screw perpendicular to the osteotomy site and applying locking and compression screws.

POSTOPERATIVE MANAGEMENT: Lower arm cast for 4 weeks until radiological signs of bone healing become apparent. To limit negative influence of rotational forces during bone healing, patients were instructed to limit forearm rotation up to 30° in pro-/supination.

RESULTS: Sixteen ulnar shortening osteotomies were performed in 15 patients (6 men, 9 women, average age 49 years) and evaluated retrospectively. In 10 cases a trauma-related pathology was the indication for the procedure. The average follow-up time was 53 weeks (range 12-93 weeks). Bone union was observed at a median of 10 weeks (range 6-33 weeks). Overall good clinical results could be achieved with an average shortening of 3.7 mm (range 2.1-16 mm). In this series, there was one nonunion.