Natural history of elbow flexion and forearm rotation contractures in obstetric brachial plexus injury.

A prospective database study was undertaken to investigate the severity and progression of elbow and forearm contractures in patients with obstetric brachial plexus injury. One-hundred and fifty-nine patients, who had not undergone nerve repair (mean age 12 years at last follow-up) (56 Narakas Group 1, 66 Group 2, 27 Group 3, 10 Group 4) were studied. Mean fixed flexion of the elbow at last follow-up was 13° for Group 1, 15° for Group 2, 19° for Group 3 and 24° for Group 4. Severe contracture of 30° or more developed in 31 children (mean age 118 months), with poorer active shoulder abduction being a significant risk factor. Onset of contracture was before the age of 5 years but did not increase substantially beyond 12 years. Active and passive pronation and supination tended to decrease with increasing injury severity. Seventeen children developed severe restriction of passive pronation (supination contracture) (mean age 69 months), and 12 developed severe restriction of passive supination at a mean of 137 months. III.