Jayme Augusto Bertelli

TRANSFER OF AXILLARY NERVE BRANCHES TO RECONSTRUCT ELBOW EXTENSION IN TETRAPLEGICS: A LABORATORY INVESTIGATION OF SURGICAL FEASIBILITY

In spinal cord injuries at the C6 level, elbow extension is lost and needs reconstruction. Traditionally, elbow extension has been reconstructed by muscle transfers, which improve function only moderately. We have hypothesized that outcomes could be ameliorated by nerve transfers rather than muscle transfers. We anatomically investigated nerve branches to the teres minor and posterior deltoid as donors for transfer to triceps motor branches. In eight formalin‐fixed cadavers, the axillary nerve, the teres minor branch, the posterior deltoid branch, the triceps long and upper medial head motor branches, and the thoracodorsal nerve were dissected bilaterally, their diameters measured and their myelinated fibers counted. To simulate surgery, using an axillary approach in two fresh cadavers, we transferred the teres minor or the posterior deltoid branch to the triceps long head and to the thoracodorsal nerve. The posterior division of the axillary nerve gave off the teres minor motor branch and then the branch to the posterior deltoid, terminating as the superior lateral brachial cutaneous nerve. The diameters of the teres minor motor branch, posterior deltoid, triceps long and upper medial head branches, and the thoracodorsal nerve all were ∼2 mm, with minimal variation. The nerves varied little in their numbers of myelinated fibers, being consistently about 1,000. Via an axillary approach, either the teres minor or the posterior deltoid branch could be transferred directly to the thoracodorsal nerve or to triceps branches without any tension.

Nerve transfer from triceps medial head and anconeus to deltoid for axillary nerve palsy.

PURPOSEnTo report our results with reconstruction of the axillary nerve by transferring the branch to the triceps lower medial head and anconeus to the anterior division of the axillary nerve.nnnMETHODSnThis study included 9 patients with isolated injury of the axillary nerve. Their average age ± SD was 35 ± 9 years, and the mean interval ± SD between injury and surgery was 6.6xa0±xa02.6 months. Through a posterior arm approach, the radial nerve branch to the lower triceps medial head and anconeus was transferred to the anterior division of the axillary nerve. We observed patients for a mean of 34 ± 7 months. At final evaluation, we measured range ofxa0shoulder motion, shoulder abduction and elbow extension strength, and abduction endurance. Patients were assessed via the deltoid extension lag test and abduction-in-internal-rotation test.nnnRESULTSnAll patients recovered deltoid function and maintained full active elbow extension. Seven of 9 patients recovered from lagging abduction in internal rotation. Abduction strength improved from approximately 40% that of the normal side at 90° of abduction preoperatively to 60% of normal strength postoperatively. There was improved endurance in abduction from approximately 25% to 65% that of the normal side, which was sufficient to eliminate all reports of shoulder pain or fatigability.nnnCONCLUSIONSnTransfer of the radial nerve branch for the lower triceps medial head and anconeus to the anterior division of the axillary nerve proved to be an effective method of deltoid reinnervation.nnnTYPE OF STUDY/LEVEL OF EVIDENCEnTherapeutic IV.

Sensory disturbances and pain complaints after brachial plexus root injury: A prospective study involving 150 adult patients

After injury of the brachial plexus, sensory disturbance in the affected limb varies according to the extent of root involvement. The goal of this study was to match sensory assessments and pain complaints with findings on CT myelo scans and surgical observations. One hundred fifty patients with supraclavicular stretch injury of the brachial plexus were operated upon within an average of 5.4 months of trauma. Preoperatively, upper limb sensation was evaluated using Semmes‐Weinstein monofilaments. Pain complaints were recorded for each patient. With lesions affecting the upper roots of the brachial plexus, hand sensation was largerly preserved. Sensory disturbances were identified over a longitudinal bundle on the lateral arm and forearm. In C8–T1 root injuries, diminished protective sensation was observed on the ulnar aspect of the hand. If the C7 root also was injured, sensation in the long finger was impaired. Eighty‐four percent of our 64 patients with total palsy reported pain, versus just 47% of our 72 patients with upper type palsies. This rate dropped to 29% in the 14 patients with a lower‐type palsy. C8 and T1, when injured, always were avulsed from the cord; when avulsion of these roots was the only nerve injury, pain was absent. Hand sensation was largely preserved in patients with partial injuries of the brachial plexus, particularly on the radial side. Even when T1 was the only preserved root, hand sensation was mostly spared. This indicates that overlapping of the dermatomal zones seems much more widespread than previously reported.

Long interpositional nerve graft consistently induces incomplete motor and sensory recovery in the rat An experimental model to test nerve repair

Motor and sensory regeneration was studied in a 40 mm long graft interposed between the sectioned stumps of the rat median nerve. Animals were behaviorally assessed from 1 to 720 days after surgery by the grasping and modified Randall-Sellito tests. Rats recovered grasping function 43.7 (S.D. +/- 2.6) days after surgery. Grasping strength attained 50 and 65% of the normal control group, 280 and 360 days after surgery, respectively. From 90 to 360 days after surgery, sensory nociceptive recovery was only 30% of the normal control group. The results indicate that motor and sensory neurons were capable of regenerating additional axonal length, but functional return was clearly better in the motor system. This model of deficient reinnervation might prove to be of interest in testing of new strategies for the enhancement of nerve recovery.

Improved Technique for Harvesting the Accessory Nerve for Transfer in Brachial Plexus Injuries

OBJECTIVE: The accessory nerve is frequently used as a donor for nerve transfer in brachial plexus injuries. In currently available techniques, nerve identification and dissection is difficult because fat tissue, lymphatic vessels, and blood vessels surround the nerve. We propose a technique for location and dissection of the accessory nerve between the deep cervical fascia and the trapezius muscle. METHODS: Twenty-eight patients with brachial plexus palsy had the accessory nerve surgically transplanted to the suprascapular nerve. To harvest the accessory nerve, the anterior border of the trapezius muscle was located 2 to 3 cm above the clavicle. The fascia over the trapezius muscle was incised and detached from the anterior surface of the muscle, initially, close to the clavicle, then proximally. The trapezius muscle was detached from the clavicle for 3 to 4 cm. The accessory nerve and its branches entering the trapezius muscle were identified. The accessory nerve was sectioned as distally as possible. To allow for accessory nerve mobilization, one or two proximal branches to the trapezius muscle were cut. The most proximal branch was always identified and preserved. A tunnel was created in the detached fascia, and the accessory nerve was passed through this tunnel to the brachial plexus. RESULTS: In all of the cases, the accessory nerve was easily identified under direct vision, without the use of electric stimulation. Direct coaptation of the accessory nerve with the suprascapular nerve was possible in all patients. CONCLUSION: The technique proposed here for harvesting the accessory nerve for transfer made its identification and dissection easier.

Transfer of the distal terminal motor branch of the extensor carpi radialis brevis to the nerve of the flexor pollicis longus: an anatomic study and clinical application in a tetraplegic patient.

BACKGROUND: In tetraplegics, thumb and finger motion traditionally has been reconstructed via orthopedic procedures. Although rarely used, nerve transfers are a viable method for reconstruction in tetraplegia. OBJECTIVE: To investigate the anatomic feasibility of transferring the distal branch of the extensor carpi radialis brevis (ECRB) to the flexor pollicis longus (FPL) nerve and to report our first clinical case. METHODS: We studied the motor branch of the ECRB and FPL in 14 cadaveric upper limbs. Subsequently, a 24-year-old tetraplegic man with preserved motion in his shoulder, elbow, wrist, and finger extension, but paralysis of thumb and finger flexion underwent surgery. Seven months after trauma, we transferred the brachialis muscle with a tendon graft to the flexor digitorum profundus. The distal nerve of the ECRB was transferred to the FPL nerve. RESULTS: The branch to the ECRB entered the muscle in its anterior and proximal third. After sending out a first collateral, the nerve runs for 2.4 cm alongside the muscle and bifurcates intramuscularly. A main branch from the anterior interosseous nerve, which entered the muscle 3 cm from its origin on the radius, innervated the FPL. The ECRB and FPL nerves had similar diameters (∼1 mm) and numbers of myelinated fibers (∼180). In our patient, 14 months after surgery, pinching and grasping were restored and measured 2 and 8 kg strength, respectively. CONCLUSION: Transfer of the ECRB distal branch to the FPL is a viable option to reconstruct thumb flexion.

Distal sensory nerve transfers in lower-type injuries of the brachial plexus.

PURPOSEnTo report the results of sensory nerve transfers to reconstruct sensation on the ulnar side of the hand in lower-type palsies of the brachial plexus.nnnMETHODSnFrom 2007 to 2009, we operated on 6 men and 2 women with a lower-type injury of the brachial plexus and observed them for a minimum of 24 months. The mean interval between the injury and surgery was 8 months (SD ± 8.6 mo). Before surgery, we documented anesthesia on the ulnar side of the hand in all patients. Donor nerves included cutaneous branches of the median nerve to the palm (n = 5) or the palmar cutaneous branch of the median nerve (n = 3). The ulnar proper digital nerve of the little finger was the recipient nerve. We evaluated sensory recovery by assessing static 2-point discrimination and sensation to Semmes-Weinstein monofilaments.nnnRESULTSnAccording to the British Medical Council system of evaluation, 5 patients scored S3 and 3 scored S3+.nnnCONCLUSIONSnIn lower-type injuries of the brachial plexus, transfer of median nerve branches that innervate the palm of the hand to the ulnar proper digital nerve of the little finger predictably restored protective sensation on the ulnar side of the hand.nnnTYPE OF STUDY/LEVEL OF EVIDENCEnTherapeutic IV.

Transfer of nerve branch to the brachialis to reconstruct elbow extension in incomplete tetraplegia: case report.

We undertook a brachialis to triceps nerve transfer to restore elbow extension in a 53-year-old man 5 months after he sustained a spine injury that resulted in a central cord syndrome. Within 3 months of surgery, the patient had recovered active elbow extension and had M3 level strength, which increased to M4 and 5 kg of strength by 12 months postoperatively. Despite transferring an antagonist nerve for triceps reinnervation, the patient had no problems controlling active elbow flexion-extension. Harvesting the brachialis nerve caused no permanent decrease in elbow flexion strength.

Transfer of a flexor digitorum superficialis motor branch for wrist extension reconstruction in C5–C8 root injuries of the brachial plexus: A case series

In brachial plexus injuries, though nerve transfers and root grafts have improved the results for shoulder and elbow reconstruction, wrist extension has received little attention. We operated on three young patients with C5–C8 root injuries of the left brachial plexus, each operated upon within 6 months of trauma. For wrist extension reconstruction, we transferred a proximal branch of the flexor digitorum superficialis to the motor branch of the extensor carpi radialis brevis. Twenty‐four months after surgery, all patients recovered some degree of active wrist motion, from full flexion to near neutral. Independent control of finger flexion and wrist extension was not observed. In C5–C8 root injuries of the brachial plexus, transfer of a flexor digitorum superficialis motor branch to the extensor carpi radialis brevis produces limited recovery.

Surgical anatomy of the platysma motor branch as a donor for transfer in brachial plexus repair

ObjectNerve transfers have become a major weapon in the battle against brachial plexus lesions. Recently, a case involving the successful use of the platysma motor branch to re-innervate the pectoralis major muscle was reported. The present anatomical study was conducted to clarify the surgical anatomy of the platysma motor nerve, in view of its potential use as a donor for transfer.MethodsMicrosurgical dissections of the facial nerve and its terminal branches were performed bilaterally in five formaldehyde-fixed cadavers, thereby yielding ten samples for study. The relationships between the platysma motor branch and adjacent structures were studied and measurements performed. Specimens were removed and histologically studied.ResultsThe platysma branch of the facial nerve was found to arise from the cervicofacial trunk. In five instances, one main nerve innervated the platysma muscle, and there was a smaller accessory nerve; in four cases, there was just a single branch to the muscle; and in one case, there was a main branch and two accessory branches. The distance between the gonion and the platysma motor branch averaged 0.8xa0cm (range 0.4–1.1xa0cm). The platysma branch received thin anastomotic rami from the transverse superficial cervical plexus. The neural surface of the platysma motor branch, on average, was 76% the surface area of the medial pectoral nerve.ConclusionThe anatomy of the platysma motor branch is predictable. Contraction of the platysma muscle is under voluntary control, which is an important quality for a donor nerve selected for transfer. The clinical usefulness of platysma motor branch transfer still must be elucidated.