The cause and management of ulnar club-hand secondary to crush injury in the palm

Abstract

Objective To investigate the cause and management of ulnar club-hand secondary to crush injury of the palm. Methods Forty eadaver hands were dissected to measure the relative position between extensor aponeurosis and phalanges, the weight and cross-sectional area of intrinsic muscles to provide anatomical basis of the causes of ulnar club-hand. From March 2007 to February 2010, six patients with ulnar club-hand secondary to severe crush injury underwent intrinsic muscle reconstruction. The causes of ulnar club-hand were investigated in these cases. Results Anatomical dissection revealed that the extensor aponeurosis and extensor tendon of the finger tend to deviate the metacarpophalangeal joint ulnarly, while the intrinsic muscles work antagonistically to pull the joint radially. In the normal hand, these two kinds of acting forces are balanced. In the absence of intrinsic muscles after severe crush injury of the hand, this balance is broken, and the hand tends to deviate ulnarly. Intrinsic muscle reconstruction in six patients with ulnar club-hand secondary to palm crush injury restored the balance and corrected the ulnar deviation deformity after 8.5 months follow-up. Thumb opposition was also improved. Conclusion The absence of hand intrinsic muscles was the main cause of ulnar club-hand in severe crush injury. In the emergency operation, ruptured intrinsic muscles should be repaired whenever possible to prevent ulnar club-hand. For established ulnar club-hand, intrinsic muscle reconstruction should be done to correct the deformity. Key words: Hand injuries; Abnormalities; Treatment outcome