We performed a prospective study using MRI in 16 consecutive infants with a mean age of 5.2 months (2.7 to 8.7) who had shown inadequate recovery from an obstetric lesion of the brachial plexus in the first three months of life, in order to identify early secondary deformities of the shoulder. Shoulders were analysed according to a standardised MRI protocol. Measurements were made of the appearance of the glenoid, glenoid version and the position of the humeral head. The appearance of the glenoid on the affected side was normal in only seven shoulders. In the remainder it was convex in seven and bioconcave in three. The degree of subluxation of the humeral head was significantly greater (p = 0.01) in the affected shoulders than in normal shoulders (157° v 170°). The presence of an abnormal appearance of the glenoid, retroversion of the glenoid and subluxation of the humeral head increased with age. There was a statistical difference (p = 0.05) between infants younger than five months and those who were older

One pattern of injury to the brachial plexus shows recovery of the fifth and sixth cervical nerves but little else. These patients have useful shoulders and functional elbow flexion, but elbow and wrist extension is weak or absent. Their hand function is negligible. We restored hand function in three such patients using free functioning muscle transfer for finger flexion and transfer of the sensory rami of the intercostal nerve to the ulnar nerve for sensation. Supplementary operations to restore elbow and wrist extension were necessary in one patient

In 15 patients who underwent open exploration of the brachial plexus, the somatosensory evoked potentials and nerve action potentials recorded at the time of operation were useful as guides to the most appropriate surgical procedure, and also in predicting the outcome in certain lesions. In three patients the apparent normality of the upper trunk of the plexus was concealing a more proximal lesion which was irrecoverable. The presence of a somatosensory evoked potential showed functional continuity in three patients in whom the C7 root was clinically involved and who recovered after operation. In five patients proximal stumps of ruptured C5 roots showed functional central continuity; this indicated their suitability for grafting. These patients recovered except one who suffered from co-existing disease. The electrophysiological studies also confirmed the clinical diagnosis of avulsion of the C8 and T1 roots and therefore prevented unnecessary dissection

We studied the motor evoked potentials (MEP) in the biceps of 25 patients with traumatic brachial plexus palsy from root avulsion after cross-innervation by intercostal nerves. We used transcranial, transcervical and transthoracic magnetic stimulation at 8 to 235 months (mean 51) after transfer of intercostal nerves to the musculocutaneous nerve. Biceps strength recovered to MRC grade 2 in eight patients, grade 3 in three and grade 4 in 14. The mean latency of the MEP in the normal biceps on transcranial stimulation was 12.5 +/- 1.3 ms and on transcervical stimulation 6.3 +/- 1.1 ms. After intercostal reinnervation the mean latency on transcranial stimulation was 21.7 +/- 4.5 ms and on transthoracic stimulation 11.6 +/- 3.8 ms. The latency of the biceps MEP after reinnervation by intercostal nerves on transcranial and transthoracic magnetic stimulation correlated well with the duration of follow-up and the latency of the MEP on transthoracic magnetic stimulation correlated significantly with muscle power

The medial rotation contracture caused by weak external rotation secondary to obstetric brachial plexus injury leads to deformation of the bones of the shoulder. Scapular hypoplasia, elevation and rotation deformity are accompanied by progressive dislocation of the humeral head. Between February and August 2005, 44 children underwent a new surgical procedure called the ‘triangle tilt’ operation to correct this bony shoulder deformity. Surgical levelling of the distal acromioclavicular triangle combined with tightening of the posterior glenohumeral capsule (capsulorrhaphy) improved shoulder function and corrected the glenohumeral axis in these patients. The posture of the arm at rest was improved and active external rotation increased by a mean of 53° (0° to 115°) in the 40 children who were followed up for more than one year.

There was a mean improvement of 4.9 points (1.7 to 8.3) of the Mallet shoulder function score after surgical correction of the bony deformity.

Aims

Between 2002 and 2011, 81 patients with a traumatic total brachial plexus injury underwent reconstruction by double free muscle transfer (DFMT, 47 cases), single muscle transfer (SMT, 16 cases) or nerve transfers (NT, 18 cases).

The use of a rotation osteotomy of the humerus in 10 patients with disabling loss of lateral rotation at the shoulder due to brachial plexus birth injuries is described. The operative technique and complications are discussed. Before operation only one patient was independent, but after operation nine of them were. Restoration of lateral rotation at the shoulder can improve the function, the appearance and the independence of these handicapped patients.

We investigated the predictive value of intra-operative neurophysiological investigations in obstetric brachial plexus injuries. Between January 2005 and June 2011 a total of 32 infants of 206 referred to our unit underwent exploration of the plexus, including neurolysis. The findings from intra-operative electromyography, sensory evoked potentials across the lesion and gross muscular response to stimulation were evaluated. A total of 22 infants underwent neurolysis alone and ten had microsurgical reconstruction. Of the former, one was lost to follow-up, one had glenoplasty and three had subsequent nerve reconstructions. Of the remaining 17 infants with neurolysis, 13 (76%) achieved a modified Mallet score > 13 at a mean age of 3.5 years (0.75 to 6.25). Subluxation or dislocation of the shoulder is a major confounding factor. The positive predictive value and sensitivity of the intra-operative EMG for C5 were 100% and 85.7%, respectively, in infants without concurrent shoulder pathology. The positive and negative predictive values, sensitivity and specificity of the three investigations combined were 77%, 100%, 100% and 57%, respectively.

In all, 20 infants underwent neurolysis alone for C6 and three had reconstruction. All of the former and one of the latter achieved biceps function of Raimondi grade 5. The positive and negative predictive values, sensitivity and specificity of electromyography for C6 were 65%, 71%, 87% and 42%, respectively.

Our method is effective in evaluating the prognosis of C5 lesion. Neurolysis is preferred for C6 lesions.

Cite this article: Bone Joint J 2013;95-B:699–705.