[Surgical management of traumatic lesions of the axillary nerve: 83 cases]

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.

Innervation of the Long Head of the Triceps Brachii in Humans-A Fresh Look

The triceps brachii muscle occupies the posterior compartment of the arm in humans and has three heads. The lateral and medial heads originate from the humerus and the long head arises from the infraglenoid tubercle of the scapula. All heads form a common tendon that inserts onto the olecranon and the deep antebrachial fascia on each side of it. Each head receives its own motor branch, which all are thought to originate from the radial nerve. However, several studies reported that the motor branch of the long head of the triceps (LHT) arises from the axillary nerve or the posterior cord. Here, we dissected 27 triceps in 15 cadavers to analyze the innervation of the LHT and found only radial innervation, which contradicts those studies. We examined studies reporting that the motor branch to the LHT in humans does not arise from the radial nerve as well as studies of the triceps in primates. Occasional variations of the innervation of skeletal muscles are normal, but a change of principal motor innervation from radial to axillary nerve has important implications. This is because the axillary nerve is often involved during shoulder injuries. The precise identification of the prevalence of axillary versus radial innervation is therefore clinically relevant for surgery, nerve drafting, and occupational and physical therapy. We conclude that the primary motor branch to the LHT arises from the radial nerve but axillary/posterior cord innervations occur occasionally. We suggest the development of a standard methodology for further studies. Anat Rec, 301:473-483, 2018. © 2018 Wiley Periodicals, Inc.

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.

[Isolated traumatic injuries of the axillary nerve. Radial nerve transfer in four cases and literatura review]

OBJECTIVE

To analyze the results of an initial series of four cases of traumatic injuries of the axillary nerve, treated by a nerve transfer from the triceps long branch of the radial nerve. An extensive analysis of the literature has also been made.

MATERIALS AND METHODS

Four patients aged between 21 and 42 years old presenting an isolated traumatic palsy of the axillary nerve were operated between January 2007 and June 2010. All cases were treated by nerve transfer six to eight months after the trauma. The results of these cases are analyzed, the same as the axillary nerve injuries series presented in the literature from 1982.

RESULTS

One year after the surgery, all patients improved their abduction a mean of 70° (range 30 to 120°), showing a M4 in the British Medical Council Scale. No patient complained of triceps weakness after the procedure. These results are similar to those published employing primary grafting for the axillary nerve.

CONCLUSIONS

Isolated injuries of the axillary nerve should be treated with surgery when spontaneous recovery is not verified 6 months after the trauma. Primary repair with grafts is the most popular surgical technique, with a rate of success of approximately 90%. The preliminary results of a nerve transfer employing the long triceps branch are similar, and a definite comparison of both techniques with a bigger number of cases should be done in the future.

Kystes para-glénoïdiens gléno-huméraux

Paraglenoid glenohumeral cysts can be observed in 2-4% of the general population, particularly in men during the third and fourth decade. On average, these cysts measure 10-20 mm in diameter and are located preferentially on the posterosuperior aspect of the glenoid. An articular origin (rim injury) is generally accepted. The pathogenesis is similar to that of meniscal cysts. Depending on the exact localization, there is generally little clinical expression. The most frequent complication involves compression of the suprascapular nerve leading to suffering of the supra and/or infraspinatus. Amyotrophy can occur without clinical expression. An attentive examination is necessary to identify the cyst. EMG is often falsely negative. MRI is currently gold standard diagnostic tool but will probably be improved with arthro-MRI. Ultrasonography and computed tomography can visualize with difficulty small cysts located very close to the bone. The best treatment is arthroscopy which enables complete cure (emptying the cyst and resection or suture of the rim). We present a review of the pertinent literature together with a retrospective series of six cases of paraglenoid glenohumeral ganglion cysts.

Facteurs pronostiques de la chirurgie du nerf axillaire

PURPOSE OF THE STUDY

We searched for prognostic factors which could influence outcome after surgery for traumatic lesion of the axillary nerve.

MATERIAL AND METHODS

Forty-five surgical interventions to repair injured axillary nerves were preformed between 1993 and 2000. We analyzed outcome at a mean 56 Months (range 15-96). Twenty-five isolated lesions were treated by nerve graft (n=20), direct suture (n=2) or neurolysis (n=3). Four associated axillary and musculocutaneous nerve injuries were treated by axillary graft and musculocutaneous neurolysis (n=2) or double grafts (n=2). Eleven injuries involving both the axillary and suprascapular nerve were treated by double nerve graft (n=4), axillary graft with suprascapular neurolysis (n=5), or axillary graft with an irreparable suprascapulary injury (n=2). Five axillary nerve lesions were associated with lesions of the rotary cuff; treatment associated suture of the cuff (n=3) or reinsertion fixation of the tuberosities (n=2) prior to nerve repair by axillary graft (n=4) or neurolysis (n=1).

RESULTS

For the isolated axillary lesions, results were very good or good for 16/20 nerve grafts, 2/2 direct sutures and 2/3 neurolyses. For the patients with an associated musculocutaneous lesion, shoulder function was considered very good for one; mean elbow flexion strength was 29% (15-50%) of the healthy side. For the eleven axillary and suprascapular injuries, outcome was very good or good for two. Very good or good results were not achieved for any of the five patients with associated cuff lesions. Factors predictive of poor outcome were a preoperative Constant score below 40 points, age over 40 Years, time to operation greater than 15 Months, and multiple nerve or associated cuff injury.

DISCUSSION

The favorable prognosis of isolated lesions of the axillary nerve was confirmed. The risk of failure does however persist and is related to late management despite well defined surgical technique.