Purpose of the study: We compared the reinnervation capacities of two nerve transfers onto the common trunk of the musculocutaneous nerve (MC), several bundles of the ulnar nerve (UN) and three intercostal nerves (IC) in patients with high brachial plexus palsy (C5C6 or C5C6C7).

Material and methods: Prospective consecutive study of two groups: group 1: 24 transfers and two to three UN bundles in 20 patients with C5C6 and four with C5C6C7, mean age at surgery 29.5 years; group 2: 15 neurotisations of the MC by CI in four C5C6 palsies and in 11 CC5C6C7 palsies, mean age at surgery 25.7 years. Mean time from accident to operation was 5.7 months, mean follow-up 29.4 months.

Results: The first contractions of the biceps were perceived clinically at 5.2 months after the surgery in group1 versus 9.9 months for group 2. Four patients in group 1 (17.0%) did not recover active flexion greater than M3 versus four (27%) in group 2. Mean force using the BMRC score was 3.6 in group 1 versus 3.2 in group 2. When elbow flexion was ≥3 (BMRC), force could be measured at 4.5kg in group 1 and 3.0 kg in group 2. For time to management up to seventh month, the two groups were comparable concerning pertinent results, but after that delay, none of the patients in group 2 achieved elbow flexion ≥3 versus 66% in group 1 up to one year. Up to the age of 40 years, results were comparable; no pertinent result was obtained after that age in group 2 versus 66% in group 1. C5C6C7 palsies had less favourable results irrespective of the technique.

Discussion: Our results show the superiority of UN transfer over CI transfer. In patients who undergo surgery before the seventh month, the rate of pertinent outcome was comparable although the flexion force was significantly greater in group 1. After seven months, only UN transfer offers hope of a useful result, up to the twelfth month. Before the age of 25 years, results are comparable, after 40, no pertinent result was observed after CI transfer while useful contraction could be obtained up to 45 years with UN transfer. C5C6C7 forms recover less well irrespective of the technique.

Purpose of the study: The slightest alteration of the antebrachial anatomic configuration, which constitutes a complex and precise biomechanical system, yields a limitation in pronosupination. Unlike the metaphysical region, little is known about rotational malunion involving the radial shaft. Kasten et all demonstrated in 30 cases that a rotational malunion of the radial shaft leads to significant loss in the pronosupination arc. If the proximal and distal radioulnar joints are intact, the interosseous membrane (IOM) probably plays an important role in this limitation.

Material and methods: The purpose of our study was to evaluate the impact of releasing the IOM on the pro-nosupination arc in an experimental model with a rotational malunion of the radial shaft inducing pronation.

Results: The study involved eight cadaver forearms free of all muscle structures and devoid of prior trauma. After stabilizing the elbow at 90°, the upper limb was fixed on a metal frame used as the reference to measure pronosupination. For each specimen, motion was measured initially, after osteotomy of the radius shaft to induce pronation then associated with longitudinal section of the IOM. A midshaft transverse osteotomy induced 78±7 pronation on average and was fixed with a DCP.

Discussion: The mean pronosupination arc was initially 175 in our population (81 pronation, 94 supination). After the creating the rotational malunion, this arc decreased significantly to 126 (SD. p> 0.05) (99 pronation, 27 supination). Release of the IOM increased this arc significantly from 27 to 153 (SD, p> 0.05) (105 pronation, 48supination)

Conclusion: Our study confirms the impact of rotational malunion on the pronosupination arc and shows the positive effect of releasing the IOM. Suppression of the IOM leads to a simpler biomechanics for the antebrachial system, allowing greater mobility of the bone one over the other. There are several clinical applications of this observation for the correction of shaft malunion of the antebrachial bones, but also certain corrective osteotomies for malpositions in the neurological patient.