Shoulder abduction and external rotation restoration with nerve transfer

Assessment, management, and rehabilitation of traumatic peripheral nerve injuries for non-surgeons

Electrodiagnostic evaluation is often requested for persons with peripheral nerve injuries and plays an important role in their diagnosis, prognosis, and management. Peripheral nerve injuries are common and can have devastating effects on patients' physical, psychological, and socioeconomic well-being; alongside surgeons, electrodiagnostic medicine specialists serve a central function in ensuring patients receive optimal treatment for these injuries. Surgical intervention-nerve grafting, nerve transfers, and tendon transfers-often plays a critical role in the management of these injuries and the restoration of patients' function. Increasingly, nerve transfers are becoming the standard of care for some types of peripheral nerve injury due to two significant advantages: first, they shorten the time to reinnervation of denervated muscles; and second, they confer greater specificity in directing motor and sensory axons toward their respective targets. As the indications for, and use of, nerve transfers expand, so too does the role of the electrodiagnostic medicine specialist in establishing or confirming the diagnosis, determining the injury's prognosis, recommending treatment, aiding in surgical planning, and supporting rehabilitation. Having a working knowledge of nerve and/or tendon transfer options allows the electrodiagnostic medicine specialist to not only arrive at the diagnosis and prognosticate, but also to clarify which nerves and/or muscles might be suitable donors, such as confirming whether the branch to supinator could be a nerve transfer donor to restore distal posterior interosseous nerve function. Moreover, post-operative testing can determine if nerve transfer reinnervation is occurring and progress patients' rehabilitation and/or direct surgeons to consider tendon transfers.

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.

Is there any difference between anterior and posterior approach for the spinal accessory to suprascapular nerve transfer? A systematic review and meta-analysis

Dual nerve transfer of the spinal accessory nerve to the suprascapular nerve (SAN-SSN) and the radial nerve to the axillary nerve is considered to be the most feasible method of restoration of shoulder abduction in brachial plexus injuries. Supraspinatus muscle plays an important role in the initiation of abduction and its functional restoration is crucial for shoulder movements. There are two possible approaches for the SAN-SSN transfer: the more conventional anterior approach and the posterior approach in the area of scapular spine, which allows more distal neurotization. Although the dual nerve transfer is a widely used method, it is unclear which approach for the SAN-SSN transfer results in better outcomes. We conducted a search of English literature from January 2001 to December 2021 using the PRISMA guidelines. Twelve studies with a total 142 patients met our inclusion criteria. Patients were divided into two groups depending on the approach used: Group A included patients who underwent the anterior approach, and Group B included patients who underwent the posterior approach. Abduction strength using the Medical Research Scale (MRC) and range of motion (ROM) were assessed. The average MRC grade was 3.57 ± 1.08 in Group A and 4.0 ± 0.65 (p = 0.65) in Group B. The average ROM was 114.6 ± 36.7 degrees in Group A and 103.4 ± 37.2 degrees in Group B (p = 0.247). In conclusion, we did not find statistically significant differences between SAN-SSN transfers performed from the anterior or posterior approach in patients undergoing dual neurotization technique for restoration of shoulder abduction.

Transdeltoid Approach to Axillary Nerve Repair: Anatomical Study and Case Series

PURPOSE

In cases of isolated paralysis of the axillary nerve, dissection of the distal stump at the posterior deltoid border can be difficult because of scarring from an injury or previous surgery. To overcome this, we propose dissecting the anterior division of the axillary nerve (ADAN) using a deltoid-splitting approach. We investigated the anatomy of the ADAN as it pertains to the transdeltoid approach and report the clinical application of this approach in 9 patients with isolated axillary nerve injury.

METHODS

The axillary nerve and its branches were dissected in 9 fresh cadaver specimens. In the clinical series, 1 patient with a lesion confined to the ADAN underwent nerve grafting. In the remaining 8 patients, the ADAN was repaired by transferring the triceps lower medial head and anconeus (TLMA) motor branch via a single-incision or double-incision posterior arm approach.

RESULTS

The posterior division of the axillary nerve does not travel around the humerus. It innervated the posterior deltoid and teres minor muscles. At the posterior margin of the humerus, the ADAN ran adjacent to the teres minor tendon. The ADAN's trajectory on the lateral side of the humerus was 65 mm (SD ± 8 mm) from the midpoint of the acromion. One centimeter from the origin, the ADAN offered a prominent branch to the middle deltoid and wound around the humerus anteriorly at the surgical neck just distal to the infraspinatus tendon. A transdeltoid approach was feasible in all our patients. The TLMA was reached without any tension in the ADAN. Middle deltoid strength in 1 patient who had received a graft scored M3, while anterior and middle deltoid strength in the remaining patients who underwent nerve transfers scored M4.

CONCLUSIONS

With axillary nerve lesions, reinnervation of the ADAN is a priority. The transdeltoid approach between the posterior and middle deltoid offers a direct and feasible approach to the ADAN.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic V.

Elevated Body Mass Index Negatively Impacts Recovery of Shoulder Abduction Strength in Triceps Motor Branch to Axillary Nerve Transfers

BACKGROUND

The purpose of this work was to evaluate the clinical outcomes of triceps motor branch to axillary nerve transfers and to identify prognostic factors which may influence these outcomes.

METHODS

A retrospective cohort included all patients who underwent a triceps motor branch to axillary nerve transfer (2010-2019) with at least 12 months of follow-up. The primary outcome measure was shoulder abduction strength assessed with British Medical Research Council (MRC) grade.

RESULTS

Ten patients were included with a mean follow-up of 19.1 (SD 5.9) months. Compared with preoperative MRC shoulder abduction strength (0.2 SD 0.4), patients significantly improved postoperatively (2.8 SD 1.6; P = .005). Increased body mass index (BMI) was significantly associated with worse postoperative MRC (P = .014).

CONCLUSION

Triceps motor branch to axillary nerve transfer is a beneficial procedure for restoring shoulder function in patients presenting with either isolated axillary nerve or brachial plexus pathology. Patients with elevated BMI may not have as robust strength recovery and should be counseled carefully regarding prognosis.

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 Outcomes of Spinal Accessory to Suprascapular Nerve Transfer Versus Nerve Grafting for Neonatal Brachial Plexus Injury

Neonatal brachial plexus injuries may cause critical limitations of upper extremity function. The optimal surgical approach to address neonatal brachial plexus injuries has not been defined. In this systematic review, we compare clinical results after spinal accessory to suprascapular nerve transfer and nerve graft techniques among patients with neonatal brachial plexus injury. [Orthopedics. 2022;45(1):7-12.].

Possible donor nerves for axillary nerve reconstruction in dual neurotization for restoring shoulder abduction in brachial plexus injuries: a systematic review and meta-analysis

Restoring shoulder abduction is one of the main priorities in the surgical treatment of brachial plexus injuries. Double nerve transfer to the axillary nerve and suprascapular nerve is widely used and considered the best option. The most common donor nerve for the suprascapular nerve is the spinal accessory nerve. However, donor nerves for axillary nerve reconstructions vary and it is still unclear which donor nerve has the best outcome. The aim of this study was to perform a systematic review on reconstructions of suprascapular and axillary nerves and to perform a meta-analysis investigating the outcomes of different donor nerves on axillary nerve reconstructions. We conducted a systematic search of English literature from March 2001 to December 2020 following PRISMA guidelines. Two outcomes were assessed, abduction strength using the Medical Research Council (MRC) scale and range of motion (ROM). Twenty-two studies describing the use of donor nerves met the inclusion criteria for the systematic review. Donor nerves investigated included the radial nerve, intercostal nerves, medial pectoral nerve, ulnar nerve fascicle, median nerve fascicle and the lower subscapular nerve. Fifteen studies that investigated the radial and intercostal nerves met the inclusion criteria for a meta-analysis. We found no statistically significant difference between either of these nerves in the abduction strength according to MRC score (radial nerve 3.66 ± 1.02 vs intercostal nerves 3.48 ± 0.64, p = 0.086). However, the difference in ROM was statistically significant (radial nerve 106.33 ± 39.01 vs. intercostal nerve 80.42 ± 24.9, p < 0.001). Our findings support using a branch of the radial nerve for the triceps muscle as a donor for axillary nerve reconstruction when possible. Intercostal nerves can be used in cases of total brachial plexus injury or involvement of the C7 root or posterior fascicle. Other promising methods need to be studied more thoroughly in order to validate and compare their results with the more commonly used methods.

Addressing common orthopaedic calamities with microsurgical solutions

Reconstructive microsurgery has been an essential aspect of orthopaedic surgery and extremity reconstruction since the introduction of the operating microscope in the mid-20^th century. The reconstructive ladder ranges from simple healing by secondary intention to complex procedures such as free tissue transfer and vascularized composite allotransplantation. As orthopaedic surgery has evolved over the past 60 years, so too have the reconstructive microsurgical skills that are often needed to address common orthopaedic surgery problems. In this article, we will discuss a variety of complex orthopaedic surgery scenarios ranging from trauma to infection to tumor resection as well as the spectrum of microsurgical solutions that can aid in their management.

Prevention and Treatment of Nerve Injuries in Shoulder Arthroplasty

➤

Nerve injuries during shoulder arthroplasty have traditionally been considered rare events, but recent electrodiagnostic studies have shown that intraoperative nerve trauma is relatively common.

➤

The brachial plexus and axillary and suprascapular nerves are the most commonly injured neurologic structures, with the radial and musculocutaneous nerves being less common sites of injury.

➤

Specific measures taken during the surgical approach, component implantation, and revision surgery may help to prevent direct nerve injury. Intraoperative positioning maneuvers and arm lengthening warrant consideration to minimize indirect injuries.

➤

Suspected nerve injuries should be investigated with electromyography preferably at 6 weeks and no later than 3 months postoperatively, allowing for primary reconstruction within 3 to 6 months of injury when indicated. Primary reconstructive options include neurolysis, direct nerve repair, nerve grafting, and nerve transfers.

➤

Secondary reconstruction is preferred for injuries presenting >12 months after surgery. Secondary reconstructive options with favorable outcomes include tendon transfers and free functioning muscle transfers.

Nerve transfers in the upper extremity: A review

Injury of the brachial plexus and peripheral nerve often result in significant upper extremity dysfunction and disability. Nerve transfers are replacing other techniques as the gold standard for brachial plexus and other proximal peripheral nerve injuries. These transfers require an intimate knowledge of nerve topography, a technically demanding Intraneural dissection and require extensive physical therapy for retraining. In this review, we present a summary of the most widely accepted nerve transfers in the upper extremity described in the current literature.

Cost-Effectiveness Analysis of Combined Dual Motor Nerve Transfers versus Alternative Surgical and Nonsurgical Management Strategies to Restore Shoulder Function Following Upper Brachial Plexus Injury

BACKGROUND

Restoration of shoulder function is an important treatment goal in upper brachial plexus injury (UBPI). Combined dual motor nerve transfer (CDNT) of spinal accessory to suprascapular and radial to axillary nerves demonstrates good functional recovery with minimal risk of perioperative complications.

OBJECTIVE

To evaluate the cost-effectiveness of CDNT vs alternative operative and nonoperative treatments for UBPI.

METHODS

A decision model was constructed to evaluate costs ($, third-party payer) and effectiveness (quality-adjusted life years [QALYs]) of CDNT compared to glenohumeral arthrodesis (GA), conservative management, and nontreatment strategies. Estimates for branch probabilities, costs, and QALYs were derived from published studies. Incremental cost-effectiveness ratios (ICER, $/QALY) were calculated to compare the competing strategies. One-way, 2-way, and probabilistic sensitivity analyses with 100 000 iterations were performed to account for effects of uncertainty in model inputs.

RESULTS

Base case model demonstrated CDNT effectiveness, yielding an expected 21.04 lifetime QALYs, compared to 20.89 QALYs with GA, 19.68 QALYs with conservative management, and 19.15 QALYs with no treatment. The ICERs for CDNT, GA, and conservative management vs nontreatment were $5776.73/QALY, $10 483.52/QALY, and $882.47/QALY, respectively. Adjusting for potential income associated with increased likelihood of returning to work after clinical recovery demonstrated CDNT as the dominant strategy, with ICER = -$56 459.54/QALY relative to nontreatment. Probabilistic sensitivity analysis showed CDNT cost-effectiveness at a willingness-to-pay threshold of $50 000/QALY in 78.47% and 81.97% of trials with and without income adjustment, respectively. Conservative management dominated in <1% of iterations.

CONCLUSION

CDNT and GA are cost-effective interventions to restore shoulder function in patients with UBPI.

Outcomes of Spinal Accessory-to-Suprascapular Nerve Transfers for Brachial Plexus Birth Injury

PURPOSE

The results of a spinal accessory nerve-to-suprascapular (SAN-SSN) nerve transfer for brachial plexus birth injuries (BPBIs) have thus far been presented only in limited case series. Our study evaluates the recovery of shoulder function of patients who underwent an SAN-SSN for BPBI as an isolated procedure or as part of a multinerve reconstruction (MNR) surgery.

METHODS

We retrospectively reviewed the medical records of patients at a single institution who underwent an SAN-SSN after BPBI. Inclusion criteria were patients with both preoperative and a minimum 12-months postoperative active movement scale (AMS) scores. Patients for whom the primary surgery involved tendon transfers were excluded. The primary outcome measures were AMS scores for shoulder abduction, forward flexion, and external rotation and secondary outcomes included the need for further shoulder surgery to improve function.

RESULTS

Seventy-three patients met the inclusion criteria. Forty-three patients (58.9%) obtained functional shoulder motion (AMS ≥ 6) of at least 1 of 3 planes (abduction/flexion/external rotation) following surgery, with 13 patients (17.8%) achieving full recovery of 1 of these shoulder motions against gravity (AMS = 7). Fifty-six patients (76.7%) did not undergo subsequent tendon transfers or corrective osteotomies to augment shoulder function. The MNR procedures were performed in 46 patients (63%), of whom 45.7% gained a functional recovery. In 27 patients for whom SAN-SSN nerve transfer was conducted in isolation, 81.5% gained functional shoulder motion. However, isolated SAN-SSNs were conducted at a later age than MNR procedures (13.2 vs 4.8 months) and had higher preoperative AMS scores. The anterior and posterior approaches for SAN-SSN were both found to be effective when used for SAN-SSN in BPBI. When the follow-up duration cutoff was set to 3 years, the outcomes were found to be superior.

CONCLUSIONS

In 76.7% of the patients, SAN-SSN was able to recover function that was sufficient to prevent tendon transfers and corrective osteotomies. A cutoff of 3 postoperative years should be used as a benchmark for analyzing the results of this procedure.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Surgery for nerve injury: current and future perspectives

In this review article, the authors offer their perspective on nerve surgery for nerve injury, with a focus on recent evolution of management and the current surgical management. The authors provide a brief historical perspective to lay the foundations of the modern understanding of clinical nerve injury and its evolving management, especially over the last century. The shift from evaluation of the nerve injury using macroscopic techniques of exploration and external neurolysis to microscopic interrogation, interfascicular dissection, and internal neurolysis along with the use of intraoperative electrophysiology were important advances of the past 50 years. By the late 20th century, the advent and popularization of interfascicular nerve grafting techniques heralded a major advance in nerve reconstruction and allowed good outcomes to be achieved in a large percentage of nerve injury repair cases. In the past 2 decades, there has been a paradigm shift in surgical nerve repair, wherein surgeons are not only directing the repair at the injury zone, but also are deliberately performing distal-targeted nerve transfers as a preferred alternative in an attempt to restore function. The peripheral rewiring approach allows the surgeon to convert a very proximal injury with long regeneration distances and (often) uncertain outcomes to a distal injury and repair with a greater potential of regenerative success and functional recovery. Nerve transfers, originally performed as a salvage procedure for severe brachial plexus avulsion injuries, are now routinely done for various less severe brachial plexus injuries and many other proximal nerve injuries, with reliably good to even excellent results. The outcomes from nerve transfers for select clinical nerve injury are emphasized in this review. Extension of the rewiring paradigm with nerve transfers for CNS lesions such as spinal cord injury and stroke are showing great potential and promise. Cortical reeducation is required for success, and an emerging field of rehabilitation and restorative neurosciences is evident, which couples a nerve transfer procedure to robotically controlled limbs and mind-machine interfacing. The future for peripheral nerve repair has never been more exciting.

An All-Anterior Approach for Quadruple Nerve Transfer for Upper Trunk Brachial Plexus Injuries

BACKGROUND

The most commonly performed nerve transfers in upper trunk (UT) or partial brachial plexus injuries (BPIs) include the spinal accessory nerve to suprascapular nerve, Oberlin, and, lately, radial nerve (RN) (branch to triceps) to axillary nerve (AN) transfers. Routinely, the former 3 procedures are performed through an anterior approach (supraclavicular plus infraclavicular), while the triceps branch of the RN-AN transfer has been performed through a posterior approach with the patient in either the prone or semilateral position, which requires a separate incision in the posterior arm. The aim of the present study was to report the outcomes for 4 cases of quadruple nerve transfers performed for UT BPI using an all-anterior approach.

METHODS

The functional outcomes of 4 consecutive cases of UT BPI treated using an all-anterior approach were analyzed in terms of improvement in motor power and range of motion at the shoulder and elbow joints.

RESULTS

The mean age was 27.5 years (range, 16-40). All had sustained injuries from road traffic accidents. The mean injury to surgery interval was 4.5 months (range, 3-6). Of the 4 patients, 2 each had pre- and postganglionic injuries. All 4 patients had 0 of M0 power in shoulder abduction and external rotation, and elbow flexion. At a mean follow-up of 28.6 months, the average shoulder abduction was 157°, with an average of 82° of external rotation. The mean elbow flexion was 104°.

CONCLUSIONS

This technique appears to be feasible, with good-to-excellent outcomes achieved without requiring a separate posterior arm incision for the RN-AN transfer.

Axillary nerve neurotization by a triceps motor branch: comparison between axillary and posterior arm approaches

Objectives

This study is aimed at comparing the functional outcome of axillary nerve neurotization by a triceps motor branch through the axillary approach and posterior arm approach.

Methods

The study included 27 patients with post-traumatic brachial plexus injury treated with axillary nerve neurotization by a triceps motor branch for functional recovery of shoulder abduction and external rotation. The patients were retrospectively evaluated and two groups were identified, one with 13 patients undergoing axillary nerve neurotization by an axillary approach and the second with 14 patients using the posterior arm approach. Patients underwent assessment of muscle strength using the scale recommended by the British Medical Research Council, preoperatively and 18 months postoperatively, with useful function recovery considered as grade M3 or greater.

Results

In the axillary approach group, 76.9% of patients achieved useful abduction function recovery and 69.2% achieved useful external rotation function recovery. In the group with posterior arm approach, 71.4% of patients achieved useful abduction function recovery and 50% achieved useful external rotation function recovery. The difference between the two groups was not statistically significant (p = 1.000 for the British Medical Research Council abduction scale and p = 0.440 for external rotation).

Conclusion

According to the British Medical Research Council grading, axillary nerve neurotization with a triceps motor branch using axillary approach or posterior arm approach shows no statistical differences.

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.

Axon Counts Yield Multiple Options for Triceps Fascicular Nerve to Axillary Nerve Transfer

PURPOSE

To evaluate the relative axonal match between potential donor and recipient nerves, so that maximal reinnervation potential may be reached with the least chance of donor site morbidity.

METHODS

In 10 fresh-frozen cadaveric specimens, the main trunk and anterior, posterior, sensory and teres minor branches of the axillary nerve were identified, as were the radial nerve branches to the long, medial, and lateral heads of the triceps. The swing distances of the triceps fascicular nerve branches and the axillary nerve branches relative to the inferior border of the teres major muscle were recorded. Histomorphological analysis and axon counts were performed on sections of each branch.

RESULTS

The median number of axons in the main axillary trunk was 7,887, with 4,052, 1,242, and 1,161 axons in the anterior, posterior, and teres minor branches, respectively. All specimens had a single long head triceps branch (median, 2,302 axons), a range of 1 to 3 branches to the medial head of the triceps (composite axon count, 2,198 axons), and 1 to 3 branches to the lateral head of the triceps (composite average, 1,462 axons). The medial and lateral head branches had sufficient swing distance to reach the anterior branch of the axillary nerve in all 10 specimens, with only 4 specimens having adequate long head branch swing distances.

CONCLUSIONS

It is anatomically feasible to transfer multiple branches of the radial nerve supplying the medial, lateral, and sometimes, long head of the triceps to all branches of the axillary nerve in an attempt to reinnervate the deltoid and teres minor muscles.

CLINICAL RELEVANCE

Understanding the axon counts of the different possible transfer combinations will improve operative flexibility and enable peripheral nerve surgeons to reinnervate for both abduction and external rotation with the highest donor/recipient axon count ratios.

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

PURPOSE

Our objective was to determine the prevalence and quality of restored external rotation (ER) in adult brachial plexus injury (BPI) patients who underwent spinal accessory nerve (SAN) to suprascapular nerve (SSN) transfer, and to identify patient and injury factors that may influence results.

METHODS

Fifty-one adult traumatic BPI patients who underwent SAN to SSN transfer between 2000 and 2013, all treated less than 1 year after injury with >1 year follow-up. The primary outcome measured was shoulder ER. The outcomes we utilized included "clinically useful ER" (motion ≥ -35° with ≥MRC 2 strength), modified British Medical Research Council (MRC) grading, and electromyographic (EMG) reinnervation.

RESULTS

EMG evidence of re-innervation was found in 85% of patients. Surgery resulted in improved ER in 41% (21/51) of shoulders at an average of 28 months follow-up. Of these, only 31% (17/51) had clinically useful ER. The average ER active range of motion was 12° from full internal rotation (Range: -60° to 90°) and MRC grade 2.2 (2-4). The only predictor of ER improvement was an isolated upper trunk (C5-C6) injury. Improved ER was clinically evident in 76%, 37% and 26% of upper trunk (UT), C5-C6-C7 and panplexus injuries, respectively (P < 0.03).

CONCLUSIONS

Although 85% had EMG signs of recovery, the SAN to SSN transfer failed to provide useful recovery of ER through reinnervation of the infraspinatus muscle in injuries involving more levels than a C5-C6 root/upper trunk pattern. In patients with greater than C5-6 level injuries alternatives to SAN to SSN transfer should be considered to restore shoulder ER. © 2016 Wiley Periodicals, Inc. Microsurgery 37:365-370, 2017.

Nerve Transfers to Restore Shoulder Function

The restoration of shoulder function after brachial plexus injury represents a significant challenge facing the peripheral nerve surgeons. This is owing to a combination of the complex biomechanics of the shoulder girdle, the multitude of muscles and nerves that could be potentially injured, and a limited number of donor options. In general, nerve transfer is favored over tendon transfer, because the biomechanics of the musculotendinous units are not altered. This article summarizes the surgical techniques and clinical results of nerve transfers for restoration of shoulder function.

Motor Nerve Transfers

Brachial plexus and peripheral nerve injuries are exceedingly common. Traditional nerve grafting reconstruction strategies and techniques have not changed significantly over the last 3 decades. Increased experience and wider adoption of nerve transfers as part of the reconstructive strategy have resulted in a marked improvement in clinical outcomes. We review the options, outcomes, and indications for nerve transfers to treat brachial plexus and upper- and lower-extremity peripheral nerve injuries, and we explore the increasing use of nerve transfers for facial nerve and spinal cord injuries. Each section provides an overview of donor and recipient options for nerve transfer and of the relevant anatomy specific to the desired function.

Within-session reliability and smallest real difference of muscle strength following nerve transfers in patients with brachial plexus injuries

PURPOSE

To quantify the smallest real difference (SRD) of muscle strength in patients with brachial plexus injuries (BPI) after nerve transfer.

METHODS

This study enrolled 16 patients with BPI who had C5-C6 and C5-C7 root injuries and who received nerve transfer of the spinal accessory nerve to the suprascapular nerve and fascicles of the ulnar nerve to the branch of the musculocutaneous nerve that innervates the biceps muscle. The quantitative peak strength of the shoulder abductor, external rotator, and elbow flexor in both arms were measured by the hand-held dynamometer. The SRD of each muscle was determined from the values of the intraclass correlation coefficient and standard error of measurement.

RESULTS

In the involved arm, peak strength ranged from 18% of the noninvolved (shoulder external rotator) to 40% of the noninvolved (shoulder abductor). The intraclass coefficient for within-session reliability revealed good to excellent reliability for muscles, ranging from 0.86 to 0.99 and 0.87 to 0.91 in the involved and noninvolved arms, respectively. The SRD values were low for the shoulder external rotator (2.6 kg) and high for the elbow flexor (3.3 kg).

CONCLUSIONS

The hand-held dynamometer is a device with good to excellent reliability for measuring the objective strength of patients with BPI in a single session. The SRD values established in the current study are more applicable for patients achieving a Medical Research Council grading of 3 or higher and can be used to detect real changes occurring after intervention, which can thereby differentiate real changes from changes that could be attributed to random variation in the measurements.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnosis II.

Advances in nerve transfer surgery

Peripheral nerve injuries are devastating injuries and can result in physical impairments, poor functional outcomes and high levels of disability. Advances in our understanding of peripheral nerve regeneration and nerve topography have lead to the development of nerve transfers to restore function. Over the past two decades, nerve transfers have been performed and modified. With the advancements in surgical management and recognition of importance of cortical plasticity, motor-reeducation and perioperative rehabilitation, nerve transfers are producing improved functional outcomes in patients with nerve injuries. This manuscript explores the recent literature as it relates to current nerve transfer techniques and advances in post-operative rehabilitation protocols, with a focus on indications, techniques and outcomes.

Comparison of objective muscle strength in C5-C6 and C5-C7 brachial plexus injury patients after double nerve transfer

PURPOSE

The purpose of this study was to evaluate the quantitative muscle strength to distinguish the outcomes of different injury levels in upper arm type brachial plexus injury (BPI) patients with double nerve transfer.

METHODS

Nine patients with C5-C6 lesions (age = 32.2 ± 13.9 year old) and nine patients with C5-C7 lesions (age = 32.4 ± 7.9 year old) received neurotization of the spinal accessory nerve to the suprascapular nerve combined with the Oberlin procedure (fascicles of ulnar nerve transfer to the musculocutaneous nerve) were recruited. The average time interval between operation and evaluation were 27.3 ± 21.0 and 26.9 ± 20.6 months for C5-C6 and C5-C7, respectively. British Medical Research Council (BMRC) scores and the objective strength measured by a handheld dynamometer were evaluated in multiple muscles to compare outcomes between C5-C6 and C5-C7 injuries.

RESULTS

There were no significant differences in BMRC scores between the groups. C5-C6 BPI patients had greater quantitative strength in shoulder flexor (P = 0.02), shoulder extensor (P < 0.01), elbow flexor (P = 0.04), elbow extensor (P = 0.04), wrist extensor (P = 0.04), and hand grip (P = 0.04) than C5-C7 BPI patients.

CONCLUSIONS

Upper arm type BPI patients have a good motor recovery after double nerve transfer. The different outcomes between C5-C6 and C5-C7 BPI patients appeared in muscles responding to hand grip, wrist extension, and sagittal movements in shoulder and elbow joints.