Evaluation of infraspinatus reinnervation and function following spinal accessory nerve to suprascapular nerve transfer in adult traumatic brachial plexus injuries

Clinical assessment in brachial plexus injury surgery: systematic review and proposal for integrated evaluation among different medical departments

BACKGROUND

Brachial plexus injury (BPI) surgery involves diversity in surgical departments including plastic surgery, hand surgery, orthopedic surgery, and neurosurgery. There is a clear scarcity in terms of unified guidelines for outcome publications due to the absence of collaboration or consensus development between departments. This study aims to identify relevant clinical parameters and their standardized presentation to address this gap.

METHODS

A systematic review was carried out to identify the clinical outcomes and methodological characteristics of the studies published regarding BPI surgery according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA). Advanced search in PubMed was performed using the MeSH terms "Brachial Plexus Injury" (Major topic) AND "Surgery" (Subheading), obtaining a total of 2382 articles. Statistical analysis was performed, and the study was registered with the PROSPERO ID: CDR42022353785.

RESULTS

A total of 136 articles were included to the systematic review, and 11,949 patients were evaluated in different clinical outcomes according to the preferences of the authors. Traumatic events around the world are the most common cause of injury. The clinical components most reported were: British Medical Research Council in motor at 82.3%, visual analog scale in pain was 21.3%, sensitive components at 26.4%, and quality of life in 16.1% of the cases.

CONCLUSIONS

The lack of standardized clinical trials highlights the need to increase the level of evidence with the aim to identify clinical evaluations among all the diverse departments to provide optimal care for BPI treatment.

The Clinical Outcomes of Spinal Accessory to Suprascapular Nerve Transfer Through a Posterior Approach

BACKGROUND

Spinal accessory nerve (SAN) to suprascapular nerve (SSN) transfer can restore function to the rotator cuff following brachial plexus injuries. The traditional anterior approach using the lateral branch of the SAN causes denervation of the lateral trapezius limiting shoulder elevation. Suprascapular nerve pathology at the suprascapular notch may be missed resulting in poor reinnervation of the rotator cuff. The posterior approach uses the medial SAN and allows decompression and visualization of the SSN at the notch and nerve transfer coaptation closer to the target muscles with a shorter reinnervation distance.

METHODS

This is a review of 28 patients from 2014 to February 2020 who underwent SAN to SSN nerve transfer via a posterior approach. Patients were evaluated for SSN pathology, external rotation power, and range of motion. Data were evaluated for high-energy trauma (HET) and low-energy trauma/nontraumatic etiology subsets.

RESULTS

A total of 8 HET (40%) patients had pathology identified at the suprascapular notch during the posterior approach, including SSN scarring, ruptures, neuromata-in-continuity, and ossification of ligaments. British Medical Research Council grade greater than or equal to 4 shoulder external rotation was achieved in 75% patients with median range of motion 137.5°.

CONCLUSIONS

Spinal accessory nerve to SSN transfer using a posterior approach allows visualization of pathology involving the SSN and coaptation of a medial SAN transfer close to the target muscles. Following HET, 8 cases (40%) had posterior pathology identified. Spinal accessory nerve to SSN transfer through a posterior approach shows improved external rotation power and range of motion.

Variation in Recommended Treatment Strategies Among American Surgeons for Actual Adult Traumatic Brachial Plexus Injury Cases

PURPOSE

The surgical management of adult traumatic brachial plexus injuries (BPI) is challenging, with no consensus on optimal strategies. This study aimed to gather preferred reconstructive strategies from BPI surgeons for actual cases from a multicenter cohort to identify areas of agreement.

METHODS

Four case files (history, physical examination, and imaging and electrodiagnostic testing results) were distributed to eight self-designated Level IV expert BPI surgeons in the United States. Each surgeon independently reviewed the cases and provided a preferred reconstructive plan via free text response.

RESULTS

For a pan-plexus case after blunt trauma (67 years old; 3 months from injury): three surgeons recommended nerve grafting upper trunk roots to distal targets. There was disagreement in shoulder reconstruction: one suggested early shoulder fusion, two preferred cranial nerve XI to suprascapular nerve (SSN) transfer, and two anticipated future salvage shoulder fusion. For elbow reconstruction, six surgeons preferred intercostal nerve to musculocutaneous nerve transfer. For an upper trunk injury from a motorcycle accident (33 years old; 6 months from injury), only one surgeon recommended nerve grafting, six preferred XI to SSN transfer, all recommended triceps-to-axillary transfer, and all but one favored a double fascicular transfer.

CONCLUSIONS

There is inconsistency in the use of nerve grafting for BPI patients, especially in pan-plexus injuries where options are limited. Variability exists in shoulder reconstruction and stability management, with some advocating early glenohumeral arthrodesis. Although single fascicular and triceps-to-axillary transfers are consistently favored, there is no consensus for restoring shoulder and elbow function when intraplexal transfers are unavailable.

CLINICAL RELEVANCE

This study highlights substantial variability in surgical approaches to BPI among experts, underscoring the need for standardized treatment protocols. Understanding these diverse strategies can inform clinical decision making and help develop more uniform guidelines to improve patient outcomes.

Contralateral C7 nerve transfer for severe pediatric brachial plexus injuries: donor site morbidity

BACKGROUND

Pediatric brachial plexus injuries (BPI) can have a devastating impact on upper extremity function. With localized lesions, nerve grafting and transfers are well-described. However, reconstruction of pan-plexus (C5-T1) injuries (PPI) requires donor nerves outside of the brachial plexus. The cross C7 (CC7) nerve transfer extended with sural nerve grafts to the contralateral recipient nerve offers the advantage of supplying robust donor axons. Though controversial in the West, CC7 transfer is routine in many Asian centers. We present a case series of pediatric patients who underwent CC7 transfer for BPI. Our objective was to catalog donor site morbidity incurred by transferring the C7 nerve root.

METHODS

This retrospective study was approved by the Institutional Review Board of our university.

INCLUSION CRITERIA

patients under 18 years old that underwent CC7 nerve transfer for BPI at our health system between 2021 and 2022. A chart review was completed to collect demographic and outcomes data.

RESULTS

Three patients underwent a complete CC7 transfer between 2021 and 2022 for BPI reconstruction. All patients underwent concomitant additional nerve transfers. Post-operative donor site sensory deficits were minimal and transient in all but one patient, who reported mild but persistent paresthesia of the donor side hand with movement of recipient side digits; however, no patients suffered donor site motor deficits (Table 1).

CONCLUSIONS

We conclude that CC7 nerve transfer is a safe surgical option to provide additional donor motor axons for PPI in pediatric patients.

Anatomical feasibility study of the infraspinatus muscle neurotization by lower subscapular nerve

OBJECTIVES

To investigate the anatomical feasibility of the infraspinatus branch of the suprascapular nerve (IB-SSN) reconstruction by lower subscapular nerve (LSN) transfer.

METHODS

The morphological study was performed on 18 adult human cadavers. The length of the distal stump of the IB-SSN, the length of the LSN available for reconstruction and diameter of both stumps were measured. The feasibility study of the LSN to IB-SSN transfer was performed.

RESULTS

The mean length of the IB-SSN to the end of its first branch was 40.9 mm (±4.6). Its mean diameter was 2.3 mm (±0.3). The mean length of the LSN stump, which was mobilized from its original course and transferred to reach the distal stump of the IB-SSN was 66.5 mm (±11.8). Its mean diameter was 2.1 mm (±0.3). The mean ratio between LSN and IB-SSN diameters was 0.9 (±0.1). The nerve transfer was feasible in 17 out of 18 cases (94.4%).

CONCLUSION

This study demonstrates that direct LSN to IB-SSN transfer is anatomically feasible in most cases in the adult population. It may be used in cases of complex scapular fractures resulting in severe suprascapular nerve injury.

Traumatic brachial plexus injury: diagnosis and treatment

PURPOSE OF THE REVIEW

Traumatic brachial plexus injuries (BPI) are devastating life-altering events, with pervasive detrimental effects on a patient's physical, psychosocial, mental, and financial well-being. This review provides an understanding of the clinical evaluation, surgical indications, and available reconstructive options to allow for the best possible functional outcomes for patients with BPI.

RECENT FINDINGS

The successful management of patients with BPI requires a multidisciplinary team approach including peripheral nerve surgeons, neurology, hand therapy, physical therapy, pain management, social work, and mental health. The initial diagnosis includes a detailed history, comprehensive physical examination, and critical review of imaging and electrodiagnostic studies. Surgical reconstruction depends on the timing of presentation and specific injury pattern. A full spectrum of techniques including neurolysis, nerve grafting, nerve transfers, free functional muscle transfers, tendon transfers, and joint arthrodesis are utilized.

SUMMARY

Despite the devastating nature of BPI injuries, comprehensive care within a multidisciplinary team, open and practical discussions with patients about realistic expectations, and thoughtful reconstructive planning can provide patients with meaningful recovery.

Comparison of Anterior vs. Dorsal Approach for Spinal Accessory to Suprascapular Nerve Transfer in Patients With a Brachial Plexus Injury and Its Outcome on Shoulder Function

Background

Brachial plexus injuries are frequently encountered in the domain of plastic surgery, mostly secondary to road traffic accidents, gunshot injuries, or falls from a height. Many modalities have been described in the management, depending on the level and duration of the injury. C5, C6 and C5, C6, C7 are two common patterns in which nerve repair and transfers are described. At our center, we practice spinal accessory to suprascapular nerve transfer in all patients with upper trunk brachial plexus injury. There are two described approaches for the spinal accessory nerve to suprascapular nerve transfer, i.e. anterior or dorsal. The rationale for doing the posterior approach is that this approach avoids damaging the suprascapular nerve at its entrance in the suprascapular notch under the suprascapular ligament during exploration due to traction.

Materials and methods

This is a retrospective study with a consecutive sampling of 23 patients presenting at Liaquat National Hospital, Karachi, with upper trunk brachial plexus injuries during the time period from January 2016 to December 2017, i.e. two years. We divided these 23 patients into two groups, one with the anterior approach and the other with a dorsal approach for spinal accessory to suprascapular nerve transfer for shoulder abduction. The mean duration of post-surgical follow-up was from 18 to 24 months and recovery and functional outcomes were assessed.

Results

Out of the 23 patients that were included, 10 patients were operated on with an anterior approach and 13 with a posterior approach. Fifty percent (50%) of patients operated with the anterior approach and 84% of patients with the posterior showed the best motor grade recovery of M4, respectively, with better performance in patients with the posterior approach as compared to the anterior approach.

Conclusion

We advocate taking a posterior approach for spinal accessory to suprascapular nerve transfer for shoulder abduction, as it has shown better results with reliable outcomes concerning shoulder abduction, angle of abduction, and range of motion.

Pathological findings identified during the posterior approach to the spinal accessory nerve after high-energy trauma

The spinal accessory to suprascapular nerve transfer is a key procedure for restoring shoulder function in upper brachial plexus injuries and is typically undertaken via an anterior approach. The anterior approach may miss injury to the suprascapular nerve about the suprascapular notch, which may explain why functional outcomes are often limited. In 2014 we adopted a posterior approach to enable better visualization of the suprascapular nerve at the notch. Over the next 6 years we have used this approach for 20 explorations after high-energy trauma. In 7/20 we identified abnormalities at the level of the suprascapular ligament, which we would not have identified with an anterior approach: there were two ruptures, two neuromas-in-continuity and three cases of scar encasement, necessitating neurolysis. Nerve transfer could be undertaken distal to the suprascapular notch, bypassing the site of injury. These pathological findings support the wider adoption of the posterior approach in cases of high-energy trauma.Level of evidence: IV.

A Cadaveric Study on the Utility of the Levator Scapulae Motor Nerve as a Donor for Brachial Plexus Reconstruction

PURPOSE

The purpose of the study was to evaluate the utility of the levator scapulae motor nerve (LSN) as a donor nerve for brachial plexus nerve transfer. We hypothesized that the LSN could be transferred to the suprascapular nerve (SSN) or long thoracic nerve (LTN) with a reliable tension-free coaptation and appropriate donor-to-recipient axon count ratio.

METHODS

Twelve brachial plexus dissections were performed on 6 adult cadavers, bilaterally. We identified the LSN, spinal accessory nerve (SAN), SSN, and LTN. Each nerve was prepared for transfer and nerve redundancies were calculated. Cross-sections of each nerve were examined histologically, and axons counted. We transferred the LSN to target first the SSN and then the LTN, in a tension-free coaptation. For reference, we transferred the distal SAN to target the SSN and LTN and compared transfer parameters.

RESULTS

Three cadavers demonstrated 2 LSN branches supplying the levator scapulae. The axon count ratio of donor-to-recipient nerve was 1:4.0 (LSN:SSN) and 1:2.1 (LSN:LTN) for a single LSN branch and 1:3.0 (LSN:SSN) and 1:1.6 (LSN:LTN) when 2 LSN branches were available. Comparatively, the axon count ratio of donor-to-recipient nerve was 1:2.5 and 1:1.3 for the SAN to the SSN and the LTN, respectively. The mean redundancy from the LSN to the SSN and the LTN was 1.7 cm (SD, 3.1 cm) and 2.9 cm (SD, 2.8 cm), and the redundancy from the SAN to the SSN and the LTN was 4.5 (SD, 0.7 cm) and 0.75 cm (SD, 1.0 cm).

CONCLUSIONS

These data support the use of the LSN as a potential donor for direct nerve transfer to the SSN and LTN, given its adequate redundancy and size match.

CLINICAL RELEVANCE

The LSN should be considered as an alternative nerve donor source for brachial plexus reconstruction, especially in 5-level injuries with scarce donor nerves. If used in lieu of the SAN during primary nerve reconstruction, trapezius tendon transfer for improved external rotation would be enabled.

Clinical outcomes report in different brachial plexus injury surgeries: a systematic review

Brachial plexus injury is a lesion that results in loss of function of the arm, and there are multiple ways of surgically approaching its treatment. Controlled trials that compare all surgical repair strategies and their clinical outcomes have not been performed. A systematic review was conducted to identify all articles that reported clinical outcomes in different surgeries (nerve transfer, nerve graft, neurolysis, end-to-end, multiple interventions, and others). Advanced search in PubMed was performed using the Mesh terms "brachial plexus injury" as the main topic and "surgery" as a subtopic, obtaining a total of 2153 articles. The clinical data for eligibility extraction was focused on collecting motor, sensory, pain, and functional recovery. A statistical analysis was performed to find the superior surgical techniques in terms of motor recovery, through the assessment of heterogeneity between groups, and of relationships between surgery and motor recovery. The frequency and the manner in which clinical outcomes are recording were described. The differences that correspond to the demographics and procedural factors were not statistically significant among groups (p > 0.05). Neurolysis showed the highest proportion of motor recovery (85.18%), with significant results between preoperative and post-operative motor assessment (p = 0.028). The proportion of motor recovery in each group according to the surgical approach differed significantly (X² = 82.495, p = 0.0001). The motor outcome was the most reported clinical outcome (97.56%), whereas the other clinical outcomes were reported in less than 15% of the included articles. Unexpectedly, neurolysis, a technique displaced by new surgical alternatives such as nerve transfer/graft, demonstrated the highest proportion of motor recovery. Clinical outcomes such as pain, sensory, and functional recovery were infrequently reported. These results introduce the need to re-evaluate neurolysis through comparative clinical trials, as well as to standardize the way in which clinical outcomes are reported.

Shoulder abduction reconstruction for C5-7 avulsion brachial plexus injury by dual nerve transfers: spinal accessory to suprascapular nerve and partial median or ulnar to axillary nerve

Results of shoulder abduction reconstruction in partial upper-type brachial plexus avulsion injuries are better when a triceps nerve is transferred to the axillary nerve in addition to the spinal accessory to suprascapular nerve transfer. However, in C5-7 avulsion injuries, the triceps nerve may be unavailable as a donor nerve. We report the results of an alternative neurotization to the axillary nerve using either a partial median or ulnar nerve. Patients with C5, 6 ± 7 avulsion injuries and weak triceps who underwent dual nerve transfers for shoulder abduction reconstruction were recruited for the study. The second neurotization to the axillary nerve was from either a partial median or ulnar nerve that had an expandable muscle innervation of ≥ M4 motor power. Patients were assessed for recovery of shoulder abduction and external rotation. Nine patients (median age = 23 years) underwent these dual neurotizations from March 2005 to April 2013. The median time to surgery was 4.5 months. Recovery of shoulder abduction averaged 114.4° (range 90°-180°) and external rotation averaged 136.3° (range 135°-140°). Final shoulder abduction power was > M3 in all 9 patients and ≥ M4 in 6 patients. One patient with partial median nerve transfer had transient hypoaesthesia in his thumb and index finger and another had a residual M4 power in his thumb and index finger flexors. In C5-7 avulsion injuries, dual nerve transfers of the spinal accessory to suprascapular nerve and partial median or ulnar nerve to axillary nerve are good options for shoulder abduction reconstruction with minimal morbidity. Level of evidence is level IV.

Anatomical aspects of the selective infraspinatus muscle neurotization by spinal accessory nerve

The suprascapular nerve (SSN) is commonly reconstructed by spinal accessory nerve (SAN) transfer. However, reinnervation of its branch to the infraspinatus muscle (IB-SSN) is poor. Reconstruction of the SSN in cases of scapular fractures is frequently neglected in clinical practice. The morphological study was performed on 25 adult human cadavers. The course and the length of SSN of minimal diameter of 2 mm within the trapezius muscle, the length of the distal stump of IB-SSN to its branching point and the length of the SSN available for reconstructive procedure were measured. The feasibility study of the SAN - IB-SSN neurotization performed by using a bony canal under the spine of scapula was performed. The mean distance of the SAN from the spine was 8.5 cm (±0.88) at the point where it perforates the trapezius muscle and 4.49 cm (±0.72) at the most distal part of the nerve. The mean length of the intramuscular portion of the nerve was 14.74 cm (±1.99). It ran under a mean latero-medial angle of 15.54^° (±2.51). The mean distance between the medial end of the scapular spine and the SAN was 2.44 cm (± 0.64). The mean length of the IB-SSN was 3.6 cm (± 0.67). The mean length of the SAN stump which was mobilized from its original course and transferred to the infraspinous fossa to reach distal stump of the IB-SSN was 8.09 cm (±1.6). Direct SAN to IB-SSN transfer is anatomically feasible in the adult population.

C5/C6 brachial plexus palsy reconstruction using nerve surgery: long-term functional outcomes

INTRODUCTION

In traumatic proximal brachial plexus lesions (i.e., C5/C6), reconstruction of the musculocutaneous, axillary and suprascapular nerves yields satisfactory short- and medium-term functional outcomes.

HYPOTHESIS

Early functional outcomes after nerve surgery will be maintained in the long-term.

METHODS

A retrospective analysis was done using the medical records of 29 patients with C5/C6 palsy treated by nerve surgery. Active range of motion and strength at the elbow (i.e., flexion) and shoulder (i.e., flexion, abduction, external rotation with the elbow at the side of the body and with the arm 90° abducted ) were evaluated clinically using a goniometre and the British Medical Research Council grading scale, respectively.

RESULTS

At a mean follow-up of 46±15 months (25;76), the mean active elbow flexion was 126°±18° (90;150) and the mean strength was 3.8±0.5 (2;4). At the shoulder, mean active flexion, abduction, external rotation with the elbow at the side of the body and with the arm 90° abducted were 109°±39° (0;180), 99°±38° (0;180°), 12°±34° (-80;70) and 3°±21° (-40;50), while mean strength was 3.6±0.8 (0;4), 3.6±0.8 (0;4), 3.4±0.9 (0;4) and 2.5±1.2 (0;4), respectively.

DISCUSSION

In cases of C5/C6 palsy, early nerve surgery yields satisfactory functional outcomes that are maintained over time for elbow flexion and shoulder elevation. However, when the teres minor is not reinnervated, it is difficult to restore satisfactory shoulder external rotation.

LEVEL OF EVIDENCE

IV, Retrospective case study.

Functional outcome predictors after spinal accessory nerve to suprascapular nerve transfer for restoration of shoulder abduction in traumatic brachial plexus injuries in adults: the effect of time from injury to surgery

BACKGROUND

Shoulder abduction is crucial for daily activities, and its restoration is one of the surgical priorities. We evaluated the predictive factors of shoulder abduction functional outcome after spinal accessory nerve (SAN) to suprascapular nerve (SSN) transfer, with special emphasis on the effect of time from injury to the surgery, in the treatment of traumatic brachial plexus injuries.

METHOD

This cohort included adult patients who underwent SAN-to-SSN transfer with a preoperative Medical Research Council strength grade 0 and a follow-up of minimum 18 months. The primary outcome was shoulder abduction function (bad, < 30°; good, 30°-60°; or excellent, > 60°). Demographics, trauma characteristics, time lapse between injury and surgery, concomitant axillary nerve reconstruction, and surgery duration were registered. Ordinal logistic regression was used to identify predictors of functional outcomes.

RESULTS

The records of 83 patients (86.7% men, mean age 28.8 ± 9.8 years) were analysed. Mean body mass index was 24.1 ± 3.7 kg/m², and 43.1% were overweight/obese. Motorcycle crashes were the most common trauma mechanism (88.0%). Excellent, good, and bad outcomes were achieved by 20.4%, 38.6%, and 41.0%, respectively. Older patients tended to have worse outcomes (p = 0.074), as well as left-sided lesions (p = 0.015) or those contralateral to manual dominance (p = 0.057). The longer the interval between injury and surgery the worse the outcome: excellent, 5.5 (4.3-7.1); good, 6.9 (5.9-8.7); and bad, 8.2 (5.7-10.1) months (p = 0.018). After multivariable analysis, longer time interval predicted lower odds of better outcomes (OR 0.823, 95% CI 0.699-0.970, p = 0.020; 17.7% lower odds of good or excellent outcome for each additional month). The odd of good or excellent outcomes was also associated with axillary nerve reconstruction (OR 2.767, 95% CI 1.016-7.536, p = 0.046), but not with age or lesion laterality.

CONCLUSIONS

Excellent or good functional outcomes for shoulder abduction were achieved by almost sixty percent of adults who underwent SAN-to-SSN transfer for reconstruction of traumatic brachial plexus injuries, associated or not with axillary nerve reconstruction strategies. Longer delays from injury to surgery predicted worse outcomes, and the best time frame seemed to be less than 6 months.

Double-Nerve Transfer to the Axillary Nerve in Traumatic Upper Trunk Brachial Plexus Injuries Using an Axillary Approach: Anatomical Description and Preliminary Case Series

BACKGROUND

Restoration of shoulder external rotation remains challenging in patients with C5/C6 brachial plexus injuries (BPI).

OBJECTIVE

To describe a double-nerve transfer to the axillary nerve (AN), targeting both its anterior and posterior motor branches, through an axillary route.

METHODS

A total of 10 fresh-frozen cadaveric brachial plexuses were dissected. Using an axillary approach, the infraclavicular brachial plexus terminal branches were exposed, including the axillary, ulnar, and radial nerves. Under microscopic magnification, the triceps long head motor branch (TLHMB), anteromedial fascicles of the ulnar nerve (UF), the anterior motor branch of the axillary nerve (AAMB), and the teres minor motor branch (TMMB) were dissected and transected to simulate 2 nerve transfers, THLMB-AAMB and UF-TMMB. Several anatomical criteria were assessed, including the overlaps between fascicles when placed side-by-side. Six patients with C5/C6 BPI were then operated on using this technique.

RESULTS

TLHMB-AAMB and UF-TMMB transfers could be simulated in all specimens, with mean overlaps of 37.1 mm and 6.5 mm, respectively. After a mean follow-up of 23 mo, all patients had recovered grade-3 strength or more in the deltoid and teres minor muscles. Mean active shoulder flexion, abduction, and external rotation with the arm 90° abducted were of 128°, 117°, and 51°, respectively. No postoperative motor deficit was found in the UF territory.

CONCLUSION

A double-nerve transfer, based on radial and ulnar fascicles, appears to be an adequate option to reanimate both motor branches of the AN, providing satisfactory shoulder active elevations and external rotation in C5/C6 BPI patients.

Adult Traumatic Brachial Plexus Injuries

Adult traumatic brachial plexus injuries are devastating life-altering injuries occurring with increasing frequency. Evaluation includes a detailed physical examination and radiologic and electrodiagnostic studies. Critical concepts in surgical management include knowledge of injury patterns, timing of surgery, prioritization in restoration of function, and management of patient expectations. Options for treatment include neurolysis, nerve grafting, or nerve transfers and should be generally performed within 6 months of injury. The use of free functioning muscle transfers can improve function both in the acute and late setting. Modern patient-specific management can often permit consistent restoration of elbow flexion and shoulder stability with the potential of prehension of the hand. Understanding the basic concepts of management of this injury is essential for all orthopaedic surgeons who treat trauma patients.

Transfer of the Lower Trapezius as a Surgical Treatment for Combined Injuries to the Suprascapular and Axillary Nerves: A Case Report

Introduction:

Combined injuries to the suprascapular and axillary nerves can result in irreversible dysfunction of the shoulder joint, with reconstruction of shoulder external rotation being an essential component of an effective treatment. Transfer of the lower portion of the trapezius to the infraspinatus has been used, with success, to regain external rotation of the shoulder.

Case Report:

We present the case of a 45-year-old man with a chronic traumatic injury of the suprascapular and axillary nerves. In addition to a surgical transfer of the lower trapezius to the infraspinatus, we included a transfer of the latissimus dorsi and teres major, with a tensor fasciaelatae graft to the supraspinatus tendon insertion, to improve the muscular strength of shoulder elevation and abduction, as well as to improve external rotation. At 24-month post-surgery, the patient had recovered 170° of shoulder elevation, 170° of abduction, and 60° of external rotation.

Conclusion:

Early recovery after surgery was achieved, with excellent improvement of the range of shoulder motion. We report the transfer of the lower trapezius to the infraspinatus might provide a useful salvage procedure for patients with poor functional prognosis of a chronic suprascapular nerve injury.

Comparison between direct repair and human acellular nerve allografting during contralateral C7 transfer to the upper trunk for restoration of shoulder abduction and elbow flexion

Direct coaptation of contralateral C7 to the upper trunk could avoid the interposition of nerve grafts. We have successfully shortened the gap and graft lengths, and even achieved direct coaptation. However, direct repair can only be performed in some selected cases, and partial procedures still require autografts, which are the gold standard for repairing neurologic defects. As symptoms often occur after autografting, human acellular nerve allografts have been used to avoid concomitant symptoms. This study investigated the quality of shoulder abduction and elbow flexion following direct repair and acellular allografting to evaluate issues requiring attention for brachial plexus injury repair. Fifty-one brachial plexus injury patients in the surgical database were eligible for this retrospective study. Patients were divided into two groups according to different surgical methods. Direct repair was performed in 27 patients, while acellular nerve allografts were used to bridge the gap between the contralateral C7 nerve root and upper trunk in 24 patients. The length of the harvested contralateral C7 nerve root was measured intraoperatively. Deltoid and biceps muscle strength, and degrees of shoulder abduction and elbow flexion were examined according to the British Medical Research Council scoring system; meaningful recovery was defined as M3–M5. Lengths of anterior and posterior divisions of the contralateral C7 in the direct repair group were 7.64 ± 0.69 mm and 7.55 ± 0.69 mm, respectively, and in the acellular nerve allografts group were 6.46 ± 0.58 mm and 6.43 ± 0.59 mm, respectively. After a minimum of 4-year follow-up, meaningful recoveries of deltoid and biceps muscles in the direct repair group were 88.89% and 85.19%, respectively, while they were 70.83% and 66.67% in the acellular nerve allografts group. Time to C5/C6 reinnervation was shorter in the direct repair group compared with the acellular nerve allografts group. Direct repair facilitated the restoration of shoulder abduction and elbow flexion. Thus, if direct coaptation is not possible, use of acellular nerve allografts is a suitable option. This study was approved by the Medical Ethical Committee of the First Affiliated Hospital of Sun Yat-sen University, China (Application ID: [2017] 290) on November 14, 2017.

Brachial plexus nerve injury and repair in a rabbit model part II: Does middle trunk injury result in loss of biceps function while repair results in recovery of biceps function

INTRODUCTION

There is conflicting anatomic and innervation data regarding the rabbit brachial plexus injury model. This study aims to validate a rabbit brachial plexus injury model. We hypothesize the middle trunk (C6, C7) is the primary innervation of the biceps, and when cut and unrepaired, would demonstrate lack of recovery and when repaired would demonstrate evidence of recovery.

MATERIALS AND METHODS

Twenty two male New Zealand white rabbits (3-4 kg) underwent unilateral surgical division of the middle trunk. Five rabbits were randomly assigned to the "no-repair" group while the remaining 17 rabbits underwent direct coaptation ("repair" group). Rabbits were followed for 12 weeks, with ultrasound measurement of biceps cross-sectional area performed preoperatively, and at 4, 8, and 12 weeks postoperatively. At a euthanasia procedure, bilateral compound muscle action potential (CMAP) and isometric tetanic force (ITF) were measured. Bilateral biceps muscles were harvested and wet muscle weight was recorded. The operative side was expressed as a percentage of the non-operated side, and differences between the no repair and repair rabbits were statistically compared.

RESULTS

The repair group demonstrated significantly higher CMA (23.3 vs. 0%, p < .05), ITF (25.6 vs. 0%, p < .05), and wet muscle weight (65.8 vs. 52.0%, p < .05) as compared to the unrepaired group. At 4 weeks postoperatively, ultrasound-measured cross-sectional area of the biceps demonstrated atrophy in both groups. At 12 weeks, the repair group had a significantly larger cross-sectional area as compared to the no-repair group (89.1 vs. 59.3%, p < .05).

CONCLUSIONS

This injury model demonstrated recovery with repair and lack of function without repair. Longer survival time is recommended for future investigations.

Double Fascicular Nerve Transfer to Musculocutaneous Branches for Restoration of Elbow Flexion in Brachial Plexus Injury

Background

Restriction of elbow flexion significantly limits upper extremity function following brachial plexus injuries. In recent years, the double fascicular nerve transfer procedure utilizing ulnar and median nerve transfer to musculocutaneous branches has shown promising functional outcomes.

Objective

To evaluate restoration of elbow flexion following a double fascicular transfer in patients with brachial plexus injuries and identify predictors of poor outcomes.

Methods

This retrospective review included 10 consecutive patients with brachial plexus injuries involving C5-C6 root avulsions who underwent the double nerve transfer procedure. The mean follow-up was 12 months and the primary outcome was assessment of elbow flexion with the use of the Medical Research Council (MRC) scale.

Results

This procedure achieved elbow flexion of MRC grade M3 or higher in 50% of our cohort. Time interval from injury to surgery showed a statistically significant inverse association with functional recovery (r = -0.73, p = 0.016). Patients who had the surgery within six months of the injury, demonstrated higher MRC grades during the follow-up (p = 0.048). There was no association between elbow flexion recovery and age, body mass index (BMI), gender, hypertension, diabetes or smoking status.

Conclusions

The double fascicular transfer to musculocutaneous may be a safe and effective treatment for restoration of elbow flexion. The procedure is associated with superior functional outcomes when performed within the first six months from the injury.

Comparative study of single and dual nerve transfers for repairing shoulder abduction

OBJECTIVE

The purpose of this study was to compare the effects of single and dual nerve transfer for the repair of shoulder abduction in patients with upper or upper and middle trunk root avulsion.

METHODS

We carried out a retrospective analysis of 20 patients with C5-C6 or C5-C7 root avulsion treated by nerve transfer in our hospital. The patients were divided into two groups according to the different operation methods. In group A, ten patients had transferred the spinal accessory nerve to the suprascapular nerve. Ten patients in group B underwent dual nerve transfer to reconstruct shoulder abduction, including the spinal accessory nerve transfer to the suprascapular nerve and two intercostal nerves or the long head of triceps nerve branch transfer to the anterior branch of the axillary nerve. There was no difference in age, preoperative interval, follow-up time, and injury type between the two groups. We used shoulder abduction strength, shoulder abduction angle, and Samardzic's shoulder joint evaluation standard as the postoperative evaluation index. Shoulder abductor muscle strength equals or above M3 was considered to be an effective recovery.

RESULTS

Of the 20 cases, 15 obtained equals or more M3 of shoulder abduction strength, and the overall effective rate was 75%. The effective rate of shoulder abduction power in group A was 60% (6/10) while group B was 90% (9/10); however, the difference was not statistically significant (p > 0.05). The average shoulder abduction angle was 55° (SD = 19.29) in group A and 77° (SD = 20.44) in group B; the angle was significantly better in group B than that in group A (p < 0.05). Based on Samardzic's standard, the excellent and good rate of group A was 90% and in group B was 50%. The difference was statistically significant (p < 0.05).

CONCLUSION

For patients with nerve root avulsion of C5-C6 or C5-C7, repairing suprascapular nerve and axillary nerve at the same time is more effective than repairing suprascapular nerve alone in terms of shoulder abduction angle and excellent rate of functional recovery of the shoulder joint. Therefore, we recommend the repair of the suprascapular nerve and the axillary nerve simultaneously if conditions permit.

Combined Radial to Axillary and Spinal Accessory Nerve (SAN) to Suprascapular Nerve (SSN) Transfers May Confer Superior Shoulder Abduction Compared with Single SA to SSN Transfer

BACKGROUND

The restoration of shoulder function after brachial plexus injury is a high priority. Shoulder abduction and stabilization can be achieved by nerve transfer procedures including spinal accessory nerve (SAN) to suprascapular nerve (SSN) and radial to axillary nerve transfer. The objective of this study is to compare functional outcomes after SAN to SSN transfer versus the combined radial to axillary and SA to SSN transfer.

METHODS

This retrospective chart review included 14 consecutive patients with brachial plexus injury who underwent SAN to SSN transfer, 4 of whom had both SA to SSN and radial to axillary nerve transfer.

RESULTS

SAN to SSN transfer achieved successful shoulder abduction (≥M3) in 64.3% of this cohort (9/14). During the long-term follow-up, patients achieved an average increase of 67.5° in shoulder abduction. There was no association between motor recovery and time from injury to surgery, age, body mass index (BMI), sex, or smoking status. The 4 patients who had SAN to SSN combined with radial to axillary nerve transfer demonstrated a statistically significant increase in the range of abduction (median, 90° vs. 42.5°, respectively; P = 0.022) compared with those who had SAN to SSN transfer alone; however, the difference in Medical Research Council (MRC) grades (MRC > M3) did not reach statistical significance (P = 0.07).

CONCLUSIONS

Patients with brachial plexus injury and an intact C7 root could benefit from radial to axillary transfer in addition to SAN to SSN transfer. There was no association between recovery of shoulder abduction and time interval from injury to surgery, age, sex, smoking, and BMI.

Spinal accessory nerve to triceps muscle transfer using long autologous nerve grafts for recovery of elbow extension in traumatic brachial plexus injuries

OBJECTIVE

Reconstructive options for brachial plexus lesions continue to expand and improve. The purpose of this study was to evaluate the prevalence and quality of restored elbow extension in patients with brachial plexus injuries who underwent transfer of the spinal accessory nerve to the motor branch of the radial nerve to the long head of the triceps muscle with an intervening autologous nerve graft and to identify patient and injury factors that influence functional triceps outcome.

METHODS

A total of 42 patients were included in this retrospective review. All patients underwent transfer of the spinal accessory nerve to the motor branch of the radial nerve to the long head of the triceps muscle as part of their reconstruction plan after brachial plexus injury. The primary outcome was elbow extension strength according to the modified Medical Research Council muscle grading scale, and signs of triceps muscle recovery were recorded using electromyography.

RESULTS

When evaluating the entire study population (follow-up range 12–45 months, mean 24.3 months), 52.4% of patients achieved meaningful recovery. More specifically, 45.2% reached Grade 0 or 1 recovery, 19.1% obtained Grade 2, and 35.7% improved to Grade 3 or better. The presence of a vascular injury impaired functional outcome. In the subgroup with a minimum follow-up of 20 months (n = 26), meaningful recovery was obtained by 69.5%. In this subgroup, 7.7% had no recovery (Grade 0), 19.2% had recovery to Grade 1, and 23.1% had recovery to Grade 2. Grade 3 or better was reached by 50% of patients, of whom 34.5% obtained Grade 4 elbow extension.

CONCLUSIONS

Transfer of the spinal accessory nerve to the radial nerve branch to the long head of the triceps muscle with an interposition nerve graft is an adequate option for restoration of elbow extension, despite the relatively long time required for reinnervation. The presence of vascular injury impairs functional recovery of the triceps muscle, and the use of shorter nerve grafts is recommended when and if possible.

Surgical strategy in extensive proximal brachial plexus palsies

PURPOSE

To describe and assess an overall surgical strategy addressing extensive proximal brachial plexus injuries (BPI).

METHODS

Forty-five consecutive patients' charts with C5-C6-C7 and C5-C6-C7-C8 BPI were reviewed. Primary procedures were nerve transfers to restore elbow function and grafts to restore shoulder function when a cervical root was available; when nerve surgery was not possible or had failed, tendon transfers were conducted at the elbow while addressing shoulder function with glenohumeral arthrodesis or humeral osteotomy. Tendon transfers were used to restore finger extension.

RESULTS

Forty-one patients underwent elbow flexion reanimation: thirty-eight had nerve transfers and eight received tendon transfers, including five cases secondary to nerve surgery failure; grade-3 strength or greater was reached in thirty-seven cases (90%). Twenty-nine patients had nerve transfers to restore elbow extension: twenty-five recovered grade-3 or grade-4 strength (86%). Forty-one patients underwent shoulder surgery: fourteen had nerve surgery and thirty-one received palliative procedures, including four cases secondary to nerve surgery failure; thirty patients recovered at least 60° of abduction and rotation (73%). Distal reconstruction was performed in thirty-seven patients, providing finger full extension in all cases but two (95%).

CONCLUSIONS

A standardized strategy may be used in extensive proximal BPI, providing overall satisfactory outcomes.

Rhomboid nerve transfer to the suprascapular nerve for shoulder reanimation in brachial plexus palsy: A clinical report

Recovery of shoulder function is a real challenge in cases of partial brachial plexus palsy. Currently, in C5-C6 root injuries, transfer of the long head of the triceps brachii branch is done to revive the deltoid muscle. Spinal accessory nerve transfer is typically used for reanimation of the suprascapular nerve. We propose an alternative technique in which the nerve of the rhomboid muscles is transferred to the suprascapular nerve. A 33-year-old male patient with a C5-C6 brachial plexus injury with shoulder and elbow flexion palsy underwent surgery 7 months after the injury. The rhomboid nerve was transferred to the suprascapular nerve and the long head of the triceps brachii branch to the axillary nerve for shoulder reanimation. A double transfer of fascicles was performed, from the ulnar and median nerves to the biceps brachii branch and brachialis branch, respectively, for elbow flexion. At 14 months' follow-up, elbow flexion was rated M4. Shoulder elevation was 85 degrees and rated M4, and external rotation was 80 degrees and rated M4. After performing a cadaver study showing that transfer of the rhomboid nerve to the suprascapular nerve is technically possible, here we report and discuss the clinical outcomes of this new transfer technique.