Shortening of the distal ulna to correct ulnar variance in osteoporotic wrist fractures treated with intra-focal pining.

The aim of this study is to correct the ulnar variance in severe osteoporotic wrist fracture treated with intra-focal pining of the distal radius, with shortening osteotomy of the distal ulna. Thirteen patients, 12 females and one male, 61-83 years old, 6-year follow-up, were treated by intra-focal pining (kapandji). When preoperatively the ulnar variance did not return to a normal value comparing to the opposite wrist, a shortening osteotomy of the ulna was performed in one stage, 4 cm proximal to the ulnar head. The fractures healed 6-8 weeks with stability and normal motion: flexion 70°, extension 60° and pronation/supination 140°. There was no pain upon palpation of distal ulna and no sign of radial impingement. Concerning the ulnar variance and starting with nine neutral values at the normal wrist, we obtained eight negative and one neutral ulnar variance after surgery. In four cases of negative variance at normal wrist, we obtained four negative ulnar variances after surgery and two cases of ulnar non-union. In cases of dorsal comminution in wrist fracture with severe osteoporosis, intra-focal pining technique is able to restore all the radiological parameters, but it could not correct the inversion of ulnar variance relative to shortening of the radius. Avoiding secondary interventions, acute shortening osteotomy of the ulna performed is a procedure which allows restoring the ulnar variance without affecting carpal stability and the mobility.