Neurotisation du nerf du chef long du muscle triceps sur le nerf axillaire, dans les paralysies isolées du deltoïde

Distal nerve transfers for peripheral nerve injuries: indications and outcomes

Distal nerve transfer is a refined surgical technique involving the redirection of healthy sacrificable nerves from one part of the body to reinstate function in another area afflicted by paralysis or injury. This approach is particularly valuable when the original nerves are extensively damaged and standard repair methods, such as direct suturing or grafting, may be insufficient. As the nerve coaptation is close to the recipient muscles or skin, distal nerve transfers reduce the time to reinnervation. The harvesting of nerves for transfer should usually result in minimal or no donor morbidity, as any anticipated loss of function is compensated for by adjacent muscles or overlapping cutaneous territory. Recent years have witnessed notable progress in nerve transfer procedures, markedly enhancing the outcomes of upper limb reconstruction for conditions encompassing peripheral nerve, brachial plexus and spinal cord injuries.

Morbidity of long head of the triceps motor branch neurotization to the axillary nerve: Retrospective subjective and objective assessment of triceps brachii strength after transfer

INTRODUCTION

Morbidity is considered to be negligible in Leechavengvongs transfer (LT) of the long head of the triceps onto the axillary nerve, but the assessment methods used may lack reproducibility. We assessed triceps strength after LT objectively by the isokinetic technique, addressing the following questions: Is strength lowered after LT compared to the healthy limb? And 2) is there a good correlation between isokinetic dynamometry and subjective assessment?

HYPOTHESIS

Isokinetic measurement shows a decrease in triceps strength at peak torque after LT compared to the healthy limb, and this morbidity is underestimated on subjective assessment.

MATERIAL AND METHODS

This single-center retrospective study included patients undergoing LT for axillary nerve trunk palsy between 2008 and 2020, with M5 triceps preoperatively on the British Medical Research Council (BMRC) scale. Twenty patients, with a mean age of 25±9years (range, 15-48years) were assessed at a mean 58±47months (range, 6-174months). Elbow extension strength was assessed on a standardized questionnaire, BMRC isometric test and isokinetic test on an angular course of 90° at 60°/sec and 180°/sec concentrically and 30°/sec excentrically.

RESULTS

Strength at 60°/sec and 180°/sec concentrically and 30°/sec excentrically was significantly lower than in the healthy limb: respectively, -17Nm, -15Nm, and -16Nm, (p<0.001) for a mean -23%. Loss of strength was mainly severe on isokinetic testing and mild on isometric testing. Seven patients reported contracture (35%), 12 fatigue (60%), and 3 weakness (15%). Satisfaction with extension strength was excellent or good for respectively 12 (60%) and 8 patients (40%). Triceps strength was graded BMRC M4 in 9 triceps (11%) and M5 in 11 (55%).

DISCUSSION

After LT, isokinetic measurement found generally severe loss of triceps strength, but without subjective impact on everyday life.

LEVEL OF EVIDENCE

IV; retrospective study.

Triceps and cutaneous radial nerve branches investigated via an axillary anterior arm approach: new findings in a fresh-cadaver anatomical study

OBJECTIVE

The authors sought to describe the anatomy of the radial nerve and its branches when exposed through an axillary anterior arm approach.

METHODS

Bilateral upper limbs of 10 fresh cadavers were dissected after dyed latex was injected into the axillary artery.

RESULTS

Via the anterior arm approach, all triceps muscle heads could be dissected and individualized. The radial nerve overlaid the latissimus dorsi tendon, bounded by the axillar artery on its superior surface, then passed around the humerus, together with the lower lateral arm and posterior antebrachial cutaneous nerve, between the lateral and medial heads of the triceps. No triceps motor branch accompanied the radial nerve's trajectory. Over the latissimus dorsi tendon, an antero-inferior bundle, containing all radial nerve branches to the triceps, was consistently observed. In the majority of the dissections, a single branch to the long head and dual innervations for the lateral and medial heads were observed. The triceps long and proximal lateral head branches entered the triceps muscle close to the latissimus dorsi tendon. The second branch to the lateral head stemmed from the triceps lower head motor branch. The triceps medial head was innervated by the upper medial head motor branch, which followed the ulnar nerve to enter the medial head on its anterior surface. The distal branch to the triceps medial head also originated near the distal border of the latissimus dorsi tendon. After a short trajectory, a branch went out that penetrated the medial head on its posterior surface. The triceps lower medial head motor branch ended in the anconeus muscle, after traveling inside the triceps medial head. The lower lateral arm and posterior antebrachial cutaneous nerve followed the radial nerve within the torsion canal. The lower lateral brachial cutaneous nerve innervated the skin over the biceps, while the posterior antebrachial cutaneous nerve innervated the skin over the lateral epicondyle and posterior surface of the forearm. The average numbers of myelinated fibers were 926 in the long and 439 in the upper lateral head and 658 in the upper and 1137 in the lower medial head motor branches.

CONCLUSIONS

The new understanding of radial nerve anatomy delineated in this study should aid surgeons during reconstructive surgery to treat upper-limb paralysis.

Triceps motor branch transfer for isolated axillary nerve injury: Outcomes in 9 patients

INTRODUCTION

Triceps motor branch transfer has been used for more than ten years to restore deltoid function after axillary nerve injury. However, there have been few reports of the outcome of this procedure in isolated axillary nerve injury.

HYPOTHESIS

Triceps motor branch transfer could be an effective method to restore deltoid function for patients with isolated axillary nerve injury.

MATERIALS AND METHODS

Nine patients who underwent triceps motor branch transfer for treatment of isolated axillary nerve injury were followed up for at least 22 months. Shoulder abduction was assessed for all patients. The DASH outcome questionnaire was completed by every patient. Electrophysiological study was performed on 7 patients.

RESULTS

All patients regained≥90° (mean, 137°) shoulder abduction. Mean DASH score decreased from 35.2 before surgery to 13.1 at the last follow-up. There was no noticeable weakness of elbow extension in any patient.

DISCUSSION

Triceps motor branch transfer provided good results and may be a feasible alternative to nerve grafting for the treatment of complete isolated axillary nerve injury.

TYPE OF STUDY

IV, retrospective cohort study.

Triceps motor branch transfer for isolated traumatic pediatric axillary nerve injuries

OBJECT

Transfer of the triceps motor branch has been used for treatment of isolated axillary nerve palsy in the adult population. However, there are no published data on the effectiveness of this procedure in the pediatric population with traumatic injuries. The authors reviewed demographics and outcomes in their series of pediatric patients who underwent this procedure.

METHODS

Six patients ranging in age from 10 to 17 years underwent triceps motor branch transfer for the treatment of isolated axillary nerve injuries between 4 and 8 months after the inciting injury. Deltoid muscle strength was evaluated using the modified British Medical Research Council (MRC) grading system. Shoulder abduction at last follow-up was measured.

RESULTS

The mean duration of follow-up was 38 months. The average postoperative MRC grading of deltoid muscle strength was 3.6 ± 1.3. The median MRC grade was 4. One patient who did not achieve an MRC grade of 3 suffered multiple injuries from high-velocity trauma. Unlike in the adult population, age, body mass index of the patient, and delay from injury to surgery were not significant factors affecting the outcome of the procedure.

CONCLUSIONS

In the pediatric population with traumatic injuries, isolated axillary nerve injury treated with triceps motor branch transfer can result in good outcomes.

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

PURPOSE

To 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.

METHODS

This 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 6.6 ± 2.6 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 of shoulder 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.

RESULTS

All 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.

CONCLUSIONS

Transfer 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.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.