Lack of full extension of the elbow is a common abnormality in patients with achondroplasia. We studied 23 patients (41 elbows) clinically and radiologically. Extension of the elbow was assessed clinically and the angle of posterior bowing of the distal humerus was measured from lateral radiographs. There was limited extension of the elbow in 28 (68.3%) and the mean loss of extension was 13.1°. Posterior bowing of the humerus was seen in all elbows with a mean angle of 17.0°. There was a positive correlation between these two measurements. Posterior bowing greater than 20° caused a loss of full elbow extension. Posterior dislocation of the radial head was seen in nine elbows (22.0%). The mean loss of extension of the elbows was 28.7° which was significantly greater than that of these elbows in which the head was not dislocated (8.7°), although posterior bowing was not significantly different between these two groups (19.3° and 16.3°). Posterior bowing of the distal humerus is a principal cause of loss of extension of the elbow. Posterior dislocation of the radial head causes further limitation of movement in the more severely affected joints.
A pronation deformity of the forearm following an obstetric brachial plexus injury causes functional and cosmetic disability. We evaluated the results of pronator teres transfer to correct their deformity in 14 children treated over a period of four years. The mean age at surgery was 7.6 years (5 to 15). The indication for surgery in each case was impairment of active supination in a forearm that could be passively supinated provided that there was no medial contracture of the shoulder and normal function of the hand. The median follow-up was 20.4 months (8 to 42). No patient was lost to follow-up. Qualitative results were also assessed. The median active supination improved from 5° (0° to 10°) to 75° (70° to 80°) with no loss of pronation. A passively correctible pronation contracture can be corrected safely and effectively by the transfer of pronator teres.
We reviewed 42 consecutive children with a supination deformity of the forearm complicating severe birth lesions of the brachial plexus. The overall incidence over the study period was 6.9% (48 of 696). It was absent in those in Narakas group I (27.6) and occurred in 5.7% of group II (13 of 229), 9.6% of group III (11 of 114) and 23.4% of group IV (18 of 77). Concurrent deformities at the shoulder, elbow, wrist and hand were always present because of muscular imbalance from poor recovery of C5 and C7, inconsistent recovery of C8 and T1 and good recovery of C6. Early surgical correction improved the function of the upper limb and hand, but there was a tendency to recurrence. Pronation osteotomy placed the hand in a functional position, and increased the arc of rotation of the forearm. The supination deformity recurred in 40% (17 of 42) of those treated by pronation osteotomy alone, probably because of remodelling of the growing bone. Children should be followed up until skeletal maturity, and the parents counselled on the likelihood of multiple operations.