Results of reinnervation of the biceps and brachialis muscles with a double fascicular transfer for elbow flexion

Self-assessed outcomes following double fascicular nerve transfer for elbow flexion

Background

Double fascicular nerve transfer (DFT) is often performed to re-animate the elbow flexors. Studies of motor recovery following this surgery have exclusively reported on the objective outcome of muscle power. Questionnaire studies allow researchers and clinicians to learn from patients and better direct care towards their needs. To date, no research has focused on self-assessed recovery following DFT for elbow flexion.

Methods

This observational cross-sectional study aimed to give an account of patient-assessed outcomes following DFT. The bespoke questionnaire included: (a) self-reported strength and (b) the Stanmore percentage of normal elbow assessment.

Results

Sixty-two patients participated in the study. Participants were grouped according to time post-surgery. Statistical analysis confirmed that data were comparable between groups (p=0.10).

Self-assessed strength

Median scores were 0.5 kg <2 years post-surgery, 3 kg at 2 to 5 years, 2 kg at 5 to 8 years and 1.3 kg in the >8 years group.

Stanmore Percentage of Normal Elbow Assessment

Mean scores (%) were 35 (SD ± 25) <2 years, 56 (SD ± 31) at 2 to 5 years, 44 (SD ± 25) at 5 to 8 years and 46 (SD ± 29) >8 years groups.

Conclusions

This is the first study of self-assessed recovery following DFT. Scores peaked around 4 years post-operation. Future research should focus on the long-term self-reported outcome of nerve transfer surgery.

Distal nerve transfers for peripheral nerve injuries: indications and outcomes

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

Optimizing donor fascicle selection in Oberlin's procedure: A retrospective review of anatomical variability using intraoperative neuromonitoring

BACKGROUND

Transfer of the fascicle carrying the flexor carpi ulnaris (FCU) branch of the ulnar nerve (UN) to the biceps/brachialis muscle branch of the musculocutaneous nerve (Oberlin's procedure), is a mainstay technique for elbow flexion restoration in patients with upper brachial plexus injury. Despite its widespread use, there are few studies regarding the anatomic location of the donor fascicle for Oberlin's procedure. Our report aims to analyze the anatomical variability of this fascicle within the UN, while obtaining quantifiable, objective data with intraoperative neuromonitoring (IONM) for donor fascicle selection.

METHODS

We performed a retrospective review of patients at our institution who underwent an Oberlin's procedure from September 2019 to July 2023. We used IONM for donor fascicle selection (greatest FCU muscle and least intrinsic hand muscle activation). We prospectively obtained demographic and electrophysiological data, as well as anatomical location of donor fascicles and post-surgical morbidities. Surgeon's perception of FCU/intrinsic muscle contraction was compared to objective muscle amplitude during IONM.

RESULTS

Eight patients were included, with a mean age of 30.5 years and an injury-to-surgery interval of 4 months. Donor fascicle was located anterior in two cases, posterior in two, radial in two and ulnar in two patients. Correlation between surgeon's perception and IONM findings were consistent in six (75%) cases. No long term motor or sensory deficits were registered.

CONCLUSIONS

Fascicle anatomy within the UN at the proximal arm is highly variable. The use of IONM can aid in optimizing donor fascicle selection for Oberlin's procedure.

The 2-by-2 Inch "Key Window" in the Upper Extremity: An Anatomical Appraisal of the Accessibility and Proximity of the Major Nerves and Vessels

BACKGROUND

The brachial plexus is a network of nerves located between the neck and axilla, which receives input from C5-T1. Distally, the nerves and blood vessels that supply the arm and forearm form a medial neurovascular bundle. The purpose of this study was to illustrate that a peripheral nerve dissection via a 2 × 2 inch window would allow for identification and isolation of the major nerves and blood vessels that supply the arm and forearm.

METHODS

A right side formalin-fixed latex-injected cadaveric arm was transected at the proximal part of the axillary fold and included the scapular attachments. Step-by-step anatomical dissection was carried out and documented with three-dimensional digital imaging.

RESULTS

A 2 × 2 inch window centered 2 inches distal to the axillary fold on the medial surface of the arm enabled access to the major neurovascular structures of the arm and forearm: the median nerve, ulnar nerve, medial antebrachial cutaneous nerve, radial nerve and triceps motor branches, musculocutaneous nerve and its biceps and brachialis branches and lateral antebrachial cutaneous nerve, basilic vein and brachial artery and vein, and profunda brachii artery.

CONCLUSIONS

Our study demonstrates that the majority of the neurovascular supply in the arm and forearm can be accessed through a 2 × 2 inch area in the medial arm. Although this "key window" may not be entirely utilized in the operative setting, our comprehensive didactic description of peripheral nerve dissection in the cadaver laboratory can help in safer identification of complex anatomy encountered during surgical procedures.

Transfer of Motor Fascicle From the Ulnar Nerve to the Axillary Nerve by Posterior Access. New Approach

ABSTRACT

We describe a new technique of transferring the motor branch ulnar nerve (UN) to the axillary nerve (AN) by posterior approach. Three patients with C5, C6, and C7 brachial plexus injury were operated. By supraclavicular approach, the spinal accessory was transferred to the suprascapular nerve. By posterior approach in the arm, the AN was identified within the quadrilateral space, and the UN was identified medially with intrafascicular dissection of a motor fascicle, which is lifted to 4 cm in length and transferred to AN. By medial approach, a motor branch from the median nerve is transferred to the biceps nerve. At a follow-up minimum of 10 months, the maximum abduction was 160 and the minimum 90 degrees. This technique, neurotization of the AN with fascicles of the UN, spinal accessory to suprascapular nerve, and median nerve branch to biceps nerve are indicated in C5-C7 avulsion when there is no radial nerve available.

LEVEL OF EVIDENCE

Level IV.

An assessment of co-contraction in reinnervated muscle

Aim: To investigate co-contraction in reinnervated elbow flexor muscles following a nerve transfer. Materials & methods: 12 brachial plexus injury patients who received a nerve transfer to reanimate elbow flexion were included in this study. Surface electromyography (EMG) recordings were used to quantify co-contraction during sustained and repeated isometric contractions of reinnervated and contralateral uninjured elbow flexor muscles. Reuslts: For the first time, this study reveals reinnervated muscles demonstrated a trend toward higher co-contraction ratios when compared with uninjured muscle and this is correlated with an earlier onset of muscle fatigability. Conclusion: Measurements of co-contraction should be considered within muscular function assessments to help drive improvements in motor recovery therapies.

Global trends and outcomes of nerve transfers for treatment of adult brachial plexus injuries

The presentation, management and outcomes of brachial plexus injuries are likely to be subject to regional differences across the globe. A comprehensive literature search was performed to identify relevant articles related to spinal accessory to suprascapular, intercostal to musculocutaneous, and ulnar and/or median nerve fascicle to biceps and/or brachialis motor branch nerve transfers for treatment of brachial plexus injuries. A total of 6007 individual brachial plexus injuries were described with a mean follow-up of 38 months. The specific indication for accessory to suprascapular and intercostal to musculocutaneous transfers were considerably different among regions (e.g. upper plexus vs. pan-plexal), while uniform for fascicular transfer for elbow flexion (e.g. upper plexus +/- C7). Similarly, functional recovery was highly variable for accessory to suprascapular and intercostal to musculocutaneous transfers, while British Medical Research Council grade ≥3 strength after fascicular transfer for elbow flexion was frequently obtained. Overall, differences in outcomes seem to be inherent to the specific transfer being utilized.Level of evidence: III.

The Evolution of the Reconstructive Strategy for Elbow Flexion for Acute C5, C6 Brachial Plexus Injuries over Two Decades

BACKGROUND

 Over the course of the past two decades, improved outcomes following brachial plexus reconstruction have been attributed to newer nerve transfer techniques. However, key factors aside from surgical techniques have brought improved consistency to elbow flexion techniques in the latter decade.

METHODS

 One-hundred seventeen patients who underwent brachial plexus reconstruction from 1996 to 2006 were compared with 120 patients from 2007 to 2017. All patients were evaluated preoperatively and postoperatively to assess the recovery time and of elbow flexion strength.

RESULTS

 In the first decade, nerve reconstruction methods included proximal nerve grafting, intercostal nerve transfer, and Oberlin-I transfer. In the second decade, newer methods such as double fascicular transfer and ipsilateral C7 division transfer to the anterior division of upper trunk were introduced. About 78.6% of the first decade group versus 87.5% of the second decade group were able to reach M3 flexion strength (p = 0.04), with shorter time recovery to reach M3 in the 2nd decade. About 59.8% of the first decade group versus 65.0% of the second decade group were able to reach M4 (p = 0.28), but no significant difference in time of recovery. In both groups, the double fascicular nerve transfer had the highest impact when introduced in the second decade. More precise magnetic resonance imaging (MRI) techniques helped to diagnose the level of injury, the roots involved and evaluate the health of the donor nerves in preparation for intraplexus transfer.

CONCLUSION

 In addition to modified techniques in nerve transfers, (1) MRI-assisted evaluation and surgical exploration of the roots with (2) more judicious choice of donor nerves for primary nerve transfer were factors that ensured reliable and outcomes in the second decade.

[Anatomical variants of the median and musculocutaneous nerve - a case report]

Traumatische Schädigungen des Plexus brachialis resultieren häufig in einer eingeschränkten oder aufgehobenen Flexionsbewegung des Ellenbogens. Die Wiederherstellung dieser Bewegung ist ein wichtiges Ziel der chirurgischen Therapie 1 2. Maßgeblich für die Flexionsbewegung und Innervation der Zielmuskeln ist der N. musculocutaneus (MSC). Dieser bildet einen der beiden Endäste des Fasciculus lateralis des Plexus brachialis (C5-C7). In den meisten Fällen verläuft er an der ventralen Oberarmseite, in der Flexorenloge, zwischen dem M. brachialis und M. biceps brachii nach distal und gibt Äste zur motorischen Innervation der beiden Muskeln ab. Er verläuft anschließend durch den Sulcus bicipitalis lateralis und durchbricht die Fascia brachii in der Ellenbeuge 3 um als Nervus cutaneus antebrachii lateralis, sensibel den Unterarm zu versorgen. Variable Verläufe des Plexus brachialis in Zusammenschau mit dem N. musculocutaneus sind beschrieben und können auf vielseitige Art und Weisen imponieren 4 5. So kann der N. musculocutaneus direkte Verbindungen zum N.medianus aufweisen, oder diesen als direkter dritter Zuschuss anteilweise bilden. Der N. medianus kann also sowohl Äste an den N. musculocutaneus abgeben als auch solche von diesem erhalten. Vorliegende Kadaverstudien zeigen in über 50+% der Fälle Verbindungen zwischen dem N. musculocutaneus und dem N. medianus, wobei ein Großteil solcher Verbindungen proximal des Eintrittes des N. musculocutaneus in den M. coracobrachialis liegt 6. Trotzdem sind diese Variationen im klinischen Alltag meist Zufallsbefunde bei chirurgischen Interventionen 7.

Versatility of the double fascicular transfer in reconstruction of elbow flexion paralysis: Intermediate term follow-up and patient-related outcome measures

OBJECTIVES

The use of fascicle transfers in the reconstruction of traumatic brachial plexus injury is well established, but limited evidence is available regarding their use in atraumatic elbow flexion paralysis. This retrospective case review aimed to verify whether median and ulnar fascicle transfers are similarly effective in atraumatic versus traumatic elbow flexion paralysis when measured using the British Medical Research Council (MRC) scale, Brachial plexus Assessment Tool (BrAT) and Stanmore Percentage of Normal Elbow Assessment (SPONEA) scores at long-term follow-up.

METHODS

All median and ulnar fascicle transfer cases performed at the Queen Elizabeth Hospital Birmingham between August 2007 and November 2018 were reviewed to compare the outcomes of transfers performed for traumatic and atraumatic indications. Data on patient demographics, mechanism and nature of injury, date of injury or symptom onset, date of operation, and other nerve transfers performed were collected. Outcome measures collected included the British MRC scale and two patient-reported outcome measures (PROMs), BrAT and SPONEA.

RESULTS

In total, 34 patients with 45 median and ulnar fascicle transfers were identified. This included 27 traumatic and seven atraumatic brachial plexus insults. Thirty patients had sufficient follow-up to be included in MRC analysis and 17 patients had sufficient follow-up to be included in PROM analysis. No significant differences were found between traumatic and atraumatic subgroups for median MRC, BrAT, or SPONEA scores.

CONCLUSIONS

This study suggests that nerve transfers might be considered effective reconstructive options in atraumatic pathology and provides validation for further research on the subject.

Staged Phrenic Nerve Elongation and Free Functional Gracilis Muscle Transplantation-A Possible Option for Late Reconstruction in Chronic Brachial Plexus Injury

PURPOSE

In patients with late brachial plexus birth injuries, sequelae after acute flaccid myelitis, or chronic adult brachial plexus injury, donor nerves for functioning muscle transplantation are often scarce. We present the results of a potential strategy using the phrenic nerve with staged free gracilis transplantation for upper extremity reanimation in these scenarios.

METHODS

A retrospective review was performed on an institutional database of brachial plexus injury or patients with palsy. All patients underwent a staged reconstruction in which the ipsilateral phrenic nerve was extended by an autogenous nerve graft (PhNG), followed by free-functioning gracilis transplantation (PhNG-gracilis).

RESULTS

Nine patients (6 cases of late brachial plexus birth injuries, 2 of acute flaccid myelitis, and 1 of adult chronic brachial plexus injury) were included in this study. The median follow-up period following the PhNG-gracilis procedure was 27 months (range, 12-72 months). The goals of the staged PhNG and PhNG-gracilis were primarily finger extension or finger flexion. In some patients, the technique was used to improve both elbow and finger function, tunneling the muscle through the flexor compartment of the upper arm and under the mobile wad at the elbow. All patients exhibited improvement of muscle strength, including in finger extension (4 patients) from M0 to M2; finger flexion (3 patients) from M0 to M3; elbow extension (1 patient) from M0 to M2; and elbow flexion (1 patient) from M2 to M4.

CONCLUSIONS

A 2-stage PhNG-gracilis may restore or enhance the residual elbow and/or finger paralysis in chronic brachial plexus injuries. A minimum follow-up period of 3 years is recommended. This technique may remain useful as one of the last reconstructive options to increase power in patients with scarce donor nerves.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic V.

A favorable suture method for size-mismatched nerve transfer: comparison with standard perineural suture in an experimental rat study

BACKGROUND

In nerve transfer for peripheral nerve injury, it is sometimes necessary to suture size-mismatched nerves. In 1993, a favorable suture method called the Ochiai suture method for size-mismatched nerve transfer was reported. However, there is currently a lack of substantial evidence beyond the original report. Therefore, this study aimed to verify the advantages of using the Ochiai suture method for size-mismatched nerve transfer.

METHODS

A total of 18 rats were evaluated in this study and randomly divided into two groups. All rats underwent femoral to sciatic nerve transfer. Specifically, group A (n = 10) underwent the Ochiai suture method, while group B (n = 8) underwent the perineural suture method. After 12 weeks postoperatively, we conducted the sciatic functional index (SFI) test, measured muscle wet-weight, and performed histological evaluations. All data were compared between the two groups, with Welch's t test for normally distributed data and Mann-Whitney's U test for non-normally distributed data. Statistical significance was set at p < 0.05.

RESULTS

The mean number of axons was significantly greater in group A than in group B at 5 mm distal to the stump (p = 0.04). Additionally, the average axonal diameter was significantly greater in group A than in group B at 5 mm and 10 mm distal to the stump (p < 0.01 and p < 0.01, respectively). However, the SFI test and measured muscle wet-weight values showed no significant differences between the two groups.

CONCLUSIONS

Our study revealed that the Ochiai suture method for size-mismatched nerve transfer in rats increases the regenerative axon numbers and diameters. These findings suggest that the Ochiai suture method could be a valuable approach for achieving effective motor function restoration in cases of size-mismatched nerve transfer.

Following a Surgical Paradigm Shift Through the Adoption of Nerve Transfers Among Board-Eligible and Practicing Plastic Surgeons

BACKGROUND

Nerve transfers represent a new paradigm in the treatment of nerve injuries. Their current level of adoption among surgeons is unknown. This study evaluates the incidence of nerve transfers on case logs of board-eligible plastic surgeons over the past 14 years and surveys practicing nerve surgeons regarding their use of this technique.

METHODS

We queried the American Board of Plastic Surgery case log database for all nerve reconstruction Current Procedural Terminology codes from 2008 to 2021 and assessed trends and relationships between geographic region, examination year, and nerve transfer use. We surveyed nerve surgery professional societies to assess trends in practice, compared with a 2017 survey.

RESULTS

A total of 1959 nerve reconstruction cases were logged by 738 candidates from 2008 to 2021. Twelve percent of cases included nerve transfers. The proportion of nerve transfer codes (Z = -11.57; P < .0001) and the proportion of candidates performing nerve transfers (Z = -9.21, P < .0001) increased over the study period. Nerve transfers were associated with geographic region (χ² = 25.826, P = .0002), with most cases performed in the Midwest (26.4%). A higher proportion of practicing nerve surgeons reported performing nerve transfers in this survey than in our 2017 survey (χ² = 16.7, P < .001).

CONCLUSIONS

There has been an increase in nerve transfers logged in the past 14 years by board-eligible plastic surgeons, as well as increased use among currently practicing nerve surgeons. Although nerve transfer use is increasing among both plastic and orthopedic surgeons, a greater proportion of nerve reconstructions include nerve transfers in the plastic surgery cohort.

Recent Advances in the Treatment of Brachial Plexus Birth Injury

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Describe methods of clinical evaluation for neurologic recovery in brachial plexus birth injury. 2. Understand the role of different diagnostic imaging modalities to evaluate the upper limb. 3. List nonsurgical strategies and surgical procedures to manage shoulder abnormality. 4. Explain the advantages and disadvantages of microsurgical nerve reconstruction and distal nerve transfers in brachial plexus birth injury. 5. Recognize the prevalence of pain in this population and the need for greater sensory outcomes evaluation.

SUMMARY

Brachial plexus birth injury (BPBI) results from closed traction injury to the brachial plexus in the neck during an infant's vertex passage through the birth canal. Although spontaneous upper limb recovery occurs in most instances of BPBI, some infants do not demonstrate adequate motor recovery within an acceptable timeline and require surgical intervention to restore upper limb function. This article reviews major advances in the management of BPBI in the past decade that include improved understanding of shoulder pathology and its impact on observed motor recovery, novel surgical techniques, new insights in sensory function and pain, and global efforts to develop standardized outcomes assessment scales.

Treatment of C5 Palsy: An International Survey of Peripheral Nerve Surgeons

STUDY DESIGN

International survey.

OBJECTIVES

C5 palsy (C5P) is a neurological complication affecting 5-10% of patients after cervical decompression surgery. Most cases improve with conservative treatment; however, nearly 20% of patients may be left with residual deficits. Guidelines are lacking on C5P management and timing of surgical intervention. Therefore, we sought to survey peripheral nerve surgeons on their management of C5P.

METHODS

An online survey was distributed centered around a patient with C5P after posterior cervical decompression and fusion. Questions included surgeon demographics, diagnostic modalities, and timing and choice of operation. Responses were summarized and the chi-squared and Kruskal-Wallis H tests were used to examine differences across specialties.

RESULTS

A total of 154 surgeons responded to the survey, of which 59 (38%) indicated that they manage C5P cases. Average time prior to operating was 4.5 ± 2.2 months for complete injuries and 6.6 ± 3.2 months for partial injuries, with neurosurgeons significantly more likely to wait longer periods for complete (P = .01) and partial injuries (P = .03). Foraminotomies were selected by 19% of surgeons, while 92% selected nerve transfers. Transfer of the ulnar nerve to the musculocutaneous nerve was the most common choice (81%), followed by transfer of the radial nerve to the axillary nerve (58%).

CONCLUSION

Consensus exists among peripheral nerve surgeons on the use of nerve transfers for surgical treatment in cases with severe motor weakness failing to improve. Most surgeons advocate for early intervention in complete injuries. Disagreement concerns the type of nerve transfer employed, timing of surgery, and efficacy of foraminotomy.

Nerve Transfers for Brachial Plexus Reconstruction in Patients over 60 Years

Negative expectations regarding nerve reconstruction in the elderly prevail in the literature, but little is known about the effectiveness of nerve transfers in patients with brachial plexus injuries aged over 60 years. We present a series of five patients (1 female, 4 male) aged between 60 and 81 years (median 62.0 years) who underwent nerve reconstruction using multiple nerve transfers in brachial plexopathies. The etiology of brachial plexus injury was trauma (n = 2), or iatrogenic, secondary to spinal surgical laminectomy, tumor excision and radiation for breast cancer (n = 3). All but one patient underwent a one-stage reconstruction including neurolysis and extra-anatomical nerve transfer alone (n = 2) or combined with anatomical reconstruction by sural nerve grafts (n = 2). One patient underwent a two-stage reconstruction, which involved a first stage anatomical brachial plexus reconstruction followed by a second stage nerve transfer. Neurotizations were performed as double (n = 3), triple (n = 1) or quadruple (n = 1) nerve or fascicular transfers. Overall, at least one year postoperatively, successful results, characterized by a muscle strength of M3 or more, were restored in all cases, two patients even achieving M4 grading in the elbow flexion. This patient series challenges the widely held dogma that brachial plexus reconstruction in older patients will produce poor outcomes. Distal nerve transfers are advantageous as they shorten the reinnervation distance. Healthy, more elderly patients should be judiciously offered the whole spectrum of reconstructive methods and postoperative rehabilitation concepts to regain useful arm and hand function and thus preserve independence after a traumatic or nontraumatic brachial plexus injury.

Restoring musculocutaneous nerve function in 146 brachial plexus operations – a retrospective analysis

INTRODUCTION

A brachial plexus lesion is a devastating injury often affecting young, male adults after traffic accidents. Therefore, surgical restoration of elbow flexion is critical for establishing antigravity movement of the upper extremity. We analyzed different methods for musculocutaneous reconstruction regarding outcome.

METHODS

We conducted a retrospective analysis of 146 brachial plexus surgeries with musculocutaneous reconstruction performed at our department from 2013 to 2017. Demographic data, surgical method, donor and graft nerve characteristics, body mass index (BMI) as well as functional outcome of biceps muscle based on medical research council (MRC) strength grades before and after surgery were analyzed. Multivariate analysis was performed using SPSS.

RESULTS

Oberlin reconstruction was the procedure performed most often (34.2%, n = 50). Nerve transfer and autologous repair showed no significant differences regarding outcome (p = 0.599, OR 0.644 CI95% 0.126-3.307). In case of nerve transfers, we found no significant difference whether reconstruction was performed with or without a nerve graft (e.g. sural nerve) (p = 0.277, OR 0.619 CI95% 0.261-1.469). Multivariate analysis identifies patient age as a strong predictor for outcome, univariate analysis indicates that nerve graft length > 15 cm and BMI of > 25 could lead to inferior outcome. When patients with early recovery (n = 19) are included into final evaluation after 24 months, the general success rate of reconstructions is 62,7% (52/83).

CONCLUSION

Reconstruction of musculocutaneous nerve after brachial plexus injury results in a high rate of clinical improvement. Nerve transfer and autologous reconstruction both show similar results. Young age was confirmed as an independent predictor for better clinical outcome. Prospective multicenter studies are needed to further clarify.

The Effectiveness of Different Nerve Transfers in the Restoration of Elbow Flexion in Adults Following Brachial Plexus Injury: A Systematic Review and Meta-Analysis

PURPOSE

Restoration of elbow flexion is an important goal in the treatment of patients with traumatic brachial plexus injury. Numerous studies have described various nerve transfers for neurotization of the musculocutaneous nerve (or its motor branches); however, there is uncertainty over the effectiveness of each method. The aim of this study was to summarize the published evidence in adults with traumatic brachial plexus injury.

METHODS

Medline, Embase, medRxiv, and bioRxiv were systematically searched from inception to April 12, 2021. We included studies that reported the outcomes of nerve transfers for the restoration of elbow flexion in adults. The primary outcome was elbow flexion of grade 4 (M4) or higher on the British Medical Research Council scale. Data were pooled using random-effects meta-analyses, and heterogeneity was explored using metaregression. Confidence intervals (CIs) were generated to the 95% level.

RESULTS

We included 64 articles, which described 13 different nerve transfers. There were 1,335 adults, of whom 813 (61%) had partial and 522 (39%) had pan-plexus injuries. Overall, 75% of the patients with partial brachial plexus injuries achieved ≥M4 (CI, 69%-80%), and the choice of donor nerve was associated with clinically meaningful differences in the outcome. Of the patients with pan-plexus injuries, 45% achieved ≥M4 (CI, 31%-60%), and overall, each month delay from the time of injury to reconstruction reduced the probability of achieving ≥M4 by 7% (CI, 1%-12%).

CONCLUSIONS

The choice of donor nerve affects the chance of attaining a British Medical Research Council score of ≥4 in upper-trunk reconstruction. For patients with pan-plexus injuries, delay in neurotization may be detrimental to motor outcomes.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Restoration of Grasp after Single-Stage Free Functioning Gracilis Muscle Transfer in Traumatic Adult Pan-Brachial Plexus Injury

BACKGROUND

A variety of approaches have been described to obtain rudimentary grasp after traumatic pan-brachial plexus injury in adults. The aim of this study is to evaluate hand prehension after a gracilis single-stage free functioning muscle transfer.

METHODS

Twenty-seven patients who underwent gracilis single-stage free functioning muscle transfer for elbow flexion and hand prehension after a pan-plexus injury were included. All patients presented with a minimum of 2 years of follow-up. Postoperative finger flexion, elbow flexion strength, preoperative and postoperative Disability of the Arm, Shoulder, and Hand questionnaire scores, secondary hand procedures, complications, and demographic characteristics were analyzed.

RESULTS

Twenty patients (74%) demonstrated active finger pull-through. Only six patients (25%) considered their hand function useful for daily activities. Disability of the Arm, Shoulder, and Hand score improved by 13.1 ± 13.7 ( P < 0.005). All patients were expected to require one secondary procedure (wrist fusion, thumb carpometacarpal fusion, and/or thumb interphalangeal fusion) because no extensor reconstruction was performed. These were performed in 89%, 78%, and 74% of patients, respectively. Four postoperative complications (hematoma, seroma, wound dehiscence, and skin paddle loss) occurred. No flap loss occurred.

CONCLUSIONS

In pan-plexus injuries, the use of a gracilis single-stage free functioning muscle transfer is an alternative to the double free functioning muscle transfer procedure and contralateral C7 transfer, especially for patients who are unable to undergo two to three important operations in a short period of time. Further research and studies are required to improve hand function in these patients.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

The reanimation of the elbow functions in avulsive injuries of the upper brachial plexus using the medial cord transfer: nuances of the technique and update

OBJECTIVES

Report on a new transfer for the reinnervation of biceps and brachialis muscles after multilevel avulsive injuries of brachial plexus provided at least T1 is viable: the Medial Cord to Musculocutaneous (MCMc) and its variant, the Medial Cord to anterior Upper Trunk (MC-aUT). The MC-aUT is indicated in agenesia of musculocutaneous nerve and when a residual function in the biceps is present. The MCMc transfer would be unfeasible in the former and contraindicated in the latter.

METHODS

Three hundred and five consecutive patients, classified according to the quality of hand function, are available for a long-term follow-up after reconstructive surgery. They had multiple cervical root avulsive injuries at two (C5-C6), three (C5-C6-C7) and four (C5-C6-C7-C8) levels. The reinnervation was obtained via an end-to-end transfer from two donor fascicles located in the medial cord (MC) and aimed at the flexor carpi ulnaris or the flexor digitorum profundus.

RESULTS

These transfers have no failures and no complications when the hand shows a normal function. In the case of suboptimal conditions of the hand, the technique is more challenging, but still has many satisfactory results. In the four-root avulsive injuries, on the contrary, strong limitations suggest that different strategies should be preferred. EMG shows a reinnervation in both biceps and brachialis muscles and this accounts for the quality of results. Tendon transfers for wrist and finger dorsiflexion, when required, remain unencumbered.

DISCUSSION

The procedures are safe, effective and easily feasible. The ideal candidate has a C5-C6 injury and a normal hand function.

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.

Promoting Nerve Regeneration: Electrical Stimulation, Gene Therapy, and Beyond

Peripheral nerve injuries often result in life-altering functional deficits even with optimal management. Unlike the central nervous system, peripheral nerves have the ability to regenerate lost axons after injury; however, axonal regeneration does not equate to full restoration of function. To overcome this physiological shortcoming, advances in nerve regeneration and repair are paramount, including electrical stimulation, gene therapy, and surgical technique advancements.

Nerve Transfers for Elbow Reconstruction in Upper and Extended Upper-Type Brachial Plexus Injuries: A Case Series

BACKGROUND

Nerve transfers for elbow flexion in brachial plexus injuries have been used with increasing frequency because of the higher rate of success and acceptable morbidity. This is especially true in upper and extended upper-type brachial plexus injuries.

OBJECTIVE

To present the clinical outcomes of nerve transfers for elbow flexion in patients with upper and extended upper-type brachial plexus injuries.

METHODS

A retrospective cohort review was done on all patients with upper and extended upper-type brachial plexus injuries from 2006 to 2017, who underwent nerve transfers for the restoration of elbow flexion. Outcome variables include Filipino version of the disability of the arm, shoulder, and hand (FIL-DASH) score, elbow flexion strength and range of motion, and pain. All statistical significance was set at P &lt; .05.

RESULTS

Fifty-six patients with nerve transfers to restore elbow flexion were included. There was a significant improvement in FIL-DASH scores in 28 patients after the nerve transfer procedure. Patients with C56 nerve root injuries and those with more than 2 years' follow-up have a higher percentage of regaining ≥M4 elbow flexion strength. Those with double nerve transfers had a higher percentage of ≥M4 elbow flexion strength, greater range of elbow flexion, and better FIL-DASH scores compared with single nerve transfers, but this did not reach statistical significance.

CONCLUSION

Nerve transfer procedures improve FIL-DASH scores in upper and upper-type brachial plexus injuries. After nerve transfer, stronger elbow flexion can be expected in patients with C56 injuries, and those with longer follow-up.

Anatomic Variations of the Musculocutaneous Nerve and Clinical Implications for Restoration of Elbow Flexion

PURPOSE

The restoration of elbow flexion is of primary importance in the management of patients with brachial plexus injuries. Superior functional outcomes via fascicle transfer from the ulnar and median nerves have resulted in this transfer being considered the mainstay of recovery of elbow flexion in patients with intact C8 and T1 function. An understanding of the anatomy of the musculocutaneous nerve (MCN) and its branching pattern is key while performing these transfers.

METHODS

A prospective cohort study was conducted in patients who underwent nerve transfer for the restoration of elbow flexion following a traumatic brachial plexus injury. The anatomic course and branching pattern of the MCN were recorded in eligible cases, both as a line diagram and using intraoperative photographs.

RESULTS

One hundred fifty patients underwent nerve transfer for the restoration of elbow flexion following an injury to the brachial plexus. The MCN in 138 patients (92%) was found to pierce the coracobrachialis muscle before emerging lateral to it. One hundred thirty-four patients (89.3%) demonstrated the "classical" anatomy. One hundred fifteen patients (76.6%) had a single primary branch to the biceps, whereas 25 patients (16.6%) demonstrated a discrete motor branch to each head. One hundred thirty-three dissections (88.6%) revealed a single muscular branch to the brachialis arising posteromedially from the MCN, distal to the origin of the branch to the biceps brachii. Notable unreported variations, such as the MCN penetrating the biceps as it descended, multiple brachialis branches, and trifurcation of divisions of the MCN, were documented.

CONCLUSIONS

Variations in MCN anatomy are quite common, and even unreported variations can be encountered.

CLINICAL RELEVANCE

Exploration of the MCN and its branches for nerve transfers requires knowledge of these anatomic variations and vigilance to prevent inadvertent injuries while dissecting them for nerve transfer surgery.

Sensorimotor Outcomes of Upper Extremity End-to-Side Nerve Transfers: A Meta-analysis

BACKGROUND

End-to-side nerve transfer (ETSNT) for treatment of peripheral nerve injuries is controversial given the myriad anatomic locations, injury types, and indications. Efficacy of ETSNT remains debated. We hypothesized differences in age, sex, transfer location, and time to surgery influence outcomes.

METHODS

We performed a search of the PubMed database for ETSNT in the upper extremity from 1988 to 2018. Age, sex, transfer location, time to surgery, donor and recipient axons, and strength and sensation outcomes as measured by Medical Research Council scale were extracted from articles. Meaningful recovery was classified as Medical Research Council Grade 3 or greater. Association between meaningful recovery and younger (<25) and older (≥25) patients, injury mechanism, sex, transfer location, donor axons, and recipient axons were calculated using a χ 2 or Fisher exact test. A logistic mixed effect model was used with time to surgery, age (categorical), transfer location, and injury type as a fixed effect, and a random paper effect was included to account for correlation among patients from the same paper.

RESULTS

One hundred fifteen patients from 11 studies were included. Neither age (continuous variable, P = 0.68) nor time to surgery ( P = 0.28) affected meaningful recovery. Injury mechanism, sex, and younger age (<25 vs ≥25 years) were not associated with meaningful recovery. Within the brachial plexus ETSNT demonstrated median M4 ± 1 postoperative strength, with trunks/cords as the primary axon donor ( P = 0.03). The musculocutaneous nerve demonstrated promising but variable results in 31 patients with median strength M3 ± 4. Digital nerves consistently demonstrated meaningful sensory recovery as both donor and recipient axons (15 of 15, 100%). Logistic regression analysis demonstrated that odds of meaningful recovery after ETSNT are significantly greater for transfers within the brachial plexus compared with the distal arm (odds ratio, 41.9; 95% CI, 1.1-1586.7, P = 0.04), but location does not significantly affect meaningful recovery ( P = 0.22).

CONCLUSIONS

Patients undergoing ETSNT for digital nerve injury demonstrated meaningful recovery. End-to-side nerve transfer seems to be more efficacious when performed within the brachial plexus. This study did not find sex, injury mechanism, or time to surgery to significantly affect meaningful recovery. Additional study is needed to better evaluate the effectiveness of ETSNT in the upper extremity.

Considerations in the Selection of Donor Nerves for Nerve Transfer for Reanimation of Elbow and Shoulder in Traumatic Brachial Plexus Injuries

The advent of nerve transfers has revolutionised the treatment of brachial plexus and peripheral nerve injuries of the upper extremity. Nerve transfers offer faster reinnervation of a denervated muscle by taking advantage of a donor nerve, branch or fascicle close to the recipient muscle. A number of considerations in respect of donor selection for nerve transfers underlie their success. In this review article, we discuss the principles of donor selection for nerve transfers, the different options available and our considerations in choosing a suitable transfer in reanimating the elbow and the shoulder. We feel this will help nerve surgeons navigate the controversies in the selection of donor nerves and make appropriate treatment decisions for their patients. Level of Evidence: V (Therapeutic).

Brachialis Muscle Activity Can Be Measured With Surface Electromyography: A Comparative Study Using Surface and Fine-Wire Electrodes

Muscle activities of the elbow flexors, especially the brachialis muscle (BR), have been measured with intramuscular electromyography (EMG) using the fine-wire electrodes. It remains unclear whether BR activity can be assessed using surface EMG. The purpose of this study was to compare the EMG patterns of the BR activity recorded during elbow flexion using surface and fine-wire electrodes and to determine whether surface EMG can accurately measure the BR activity. Six healthy men were asked to perform two tasks—a maximum isometric voluntary contractions (MVICs) task and an isotonic elbow-flexion task without lifting any weight. The surface and intramuscular EMG were simultaneously recorded from the BR and the long and short heads of the biceps brachii muscle (BBLH and BBSH, respectively). The locations of the muscles were identified and marked under ultrasonographic guidance. The peak cross-correlation coefficients between the EMG signals during the MVICs task were calculated. For the isotonic elbow-flexion task, the EMG patterns for activities of each muscle were compared between the surface and the fine-wire electrodes. All cross-correlation coefficients between the surface EMG signals from the muscles were lower than 0.3. Furthermore, the EMG patterns of the BR activity were not significantly different between the surface and the fine-wire electrodes. The BR has different EMG pattern from the BBLH and the BBSH. The BR activity, conventionally measured with intramuscular EMG, can be accurately accessed with surface EMG during elbow flexion performed without lifting any weight, independent from the BBLH and BBSH activities.

A novel dual nerve transfer for restoration of shoulder function and sensory recovery of the hand, in patients with C567 traumatic root avulsion of the brachial plexus

OBJECTIVE

The objective of our study is to determine the anatomical viability in cadavers of a novel doble nerve transfer technique for simultaneous reanimation of shoulder abduction and sensory recovery of the hand, in patients with brachial plexus injuries sustaining a C5-C6-C7 roots avulsion. These new transfers should be complemented in the clinical setting with other classic nerve transfers, i.e.: (1) a spinal accessory to suprascapular for shoulder abduction and stability, (2) ulnar nerve fascicles to the biceps branches of the musculocutaneous for elbow flexion, and (3) intercostal to triceps branches for elbow extension.

METHODS

The proposed surgical technique includes (1) transferring motor fascicles of the median nerve (MNF), as donors to the axillary nerve (AN), and (2) the whole medial antebrachial cutaneous nerve (MACN) to the lateral contribution (sensory) of the median nerve (LCMN), both without the use of interposed nerve grafts. These techniques were performed in eight cadaveric upper extremities. Analyzed variables were: donor and receptor nerves diameter, length and distance of donor and receptors nerves, and axonal count.

RESULTS

The mean distance between the MNF and its point of coaptation to the AN was 19 mm. The average length of each one of the MNF, after distal dissection, was 46.5 mm. The average diameter of each fascicle of the median nerve at its coaptation point with the axillary nerve was 0.8 mm, while the average diameter of the latter was 3.9 mm. The average distance between the MACN and its point of coaptation to the LCMN, was 16.5 mm. The average diameter of the MACN and the LCMN at their point of coaptation, were 2.7 mm and 3.5 mm, respectively.

CONCLUSION

These nerve transfers are anatomically viable and could be a complement for other currently used techniques that can be employed in severely injured C567 brachial plexus patients.

Double Fascicular Transfer Using Partially Injured Donor Nerves: Is It Powerful Enough to Restore Elbow Flexion in Acute Brachial Plexus Injuries?

BACKGROUND

 Loss of elbow flexion is a common sequela of acute brachial plexus injuries (BPIs). The Mackinnon/Oberlin-II double fascicular transfer (DFT) is a widely used method to restore this function in acute C5-6 or C5-7 injuries. This study attempted to evaluate if this technique can be applied reliably for cases involving C8 and/or T1 injuries.

METHODS

 Adult patients with acute BPIs who underwent the Mackinnon/Oberlin-II DFT in our center between 2008 and 2018 were retrospectively identified. Group I (n = 37) included patients with only C5-6 or C5-7 injury, while group II (n = 32) patients presented C5-8 ± T1 injuries. The demographic data, pre- and postoperative neurologic evaluations, electrodiagnostic studies, and grip strength assessment were collected.

RESULTS

 A total of 69 patients met the inclusion criteria. Preoperatively, the patients in group II presented poorer nerve conduction and electromyography in both the median and the ulnar nerves and the supply muscles. The percentage of M3 achievement in both groups was 91.9 versus 87.5% and M4 was 73.0 and 71.9%, respectively, which both were not statically significant but the achievement of group II was slower than the group I, 1 to 2 months slower, respectively. Both groups had 57.57 and 46.0% of the postoperative grip power compared with the healthy side, the result of shoulder abduction was not different (p = 0.480).

CONCLUSION

 With careful preoperative evaluation, early intervention, appropriate intraoperative functional fascicle selection, and aggressive postoperative rehabilitation, indications for the Mackinnon/Oberlin-II DFT technique can safely include acute C5-8 injuries and even partial T1 acute BPIs.

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.

Prevention and Treatment of Nerve Injuries in Shoulder Arthroplasty

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

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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.

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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.

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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.

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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.

Impact of Body Mass Index and Comorbidities on Outcomes in Upper Extremity Nerve Transfers

BACKGROUND

 There is a paucity of research investigating the impact of patient comorbidities, such as obesity and smoking, on nerve transfer outcomes. The objective of this retrospective cohort study was to evaluate the impact of body mass index (BMI) and comorbidities on the clinical outcomes of upper extremity nerve transfers.

METHODS

 A retrospective cohort study was executed. Patients were eligible for inclusion if they had an upper extremity nerve transfer with a minimum of 12-months follow-up. Data was collected regarding demographics, comorbidities, injury etiology, nerve transfer, as well as preoperative and postoperative clinical assessments. The primary outcome measure was strength of the recipient nerve innervated musculature. Statistical analysis used the Mann-Whitney U test, Wilcoxon signed-rank test, and Spearman's rho.

RESULTS

 Thirty-eight patients undergoing 43 nerve transfers were eligible for inclusion. Patients had a mean age of 48.8 years and a mean BMI of 27.4 kg/m² (range:19.7-39.0). Injuries involved the brachial plexus (32%) or its terminal branches (68%) with the most common etiologies including trauma (50%) and compression (26%). Anterior interosseous nerve to ulnar motor nerve (35%) was the most common transfer performed. With a mean follow-up of 20.1 months, increased BMI (p = 0.036) and smoking (p = 0.021) were associated with worse postoperative strength.

CONCLUSION

 This retrospective cohort study demonstrated that increased BMI and smoking may be associated with worse outcomes in upper extremity nerve transfers-review of the literature yields ambiguity in both regards. To facilitate appropriate patient selection and guide expectations regarding prognosis, further experimental and clinical work is warranted.

Nerve transfers to restore femoral nerve function following oncologic nerve resection

INTRODUCTION

Advances in the care of soft-tissue tumors, including imaging capabilities and adjuvant radiation therapy, have broadened the indications and opportunities to pursue surgical limb salvage. However, peripheral nerve involvement and femoral nerve resection can still result in devastating functional outcomes. Nerve transfers offer a versatile solution to restore nerve function following tumor resection.

METHODS

Two cases were identified by retrospective review. Patient and disease characteristics were gathered. Preoperative and postoperative motor function were assessed using the Medical Research Council Muscle Scale. Patient-reported pain levels were assessed using the numeric rating scale.

RESULTS

Nerve transfers from the obturator and sciatic nerve were employed to restore knee extension. Follow up for Case 1 was 24 months, 8 months for Case 2. In both patients, knee extension and stabilization of gait without bracing was restored. Patient also demonstrated 0/10 pain (an average improvement of 5 points) with decreased neuromodulator and pain medication use.

CONCLUSION

Nerve transfers can restore function and provide pain control benefits and ideally are performed at the time of tumor extirpation. This collaboration between oncologic and nerve surgeons will ultimately result in improved functional recovery and patient outcomes.

Restoration of elbow flexion in adult traumatic brachial plexus injury - a quantitative analysis of results of single versus double nerve transfer

BACKGROUND

Restoration of elbow flexion is one of the key components of adult brachial plexus surgery. Nerve transfers are routinely used to attain elbow flexion.

PURPOSE

This study aims to quantify the recovery of elbow flexion power and to compare the outcome following single nerve transfer and double nerve transfer to branches of the musculocutaneous nerve in adult traumatic brachial plexus injury.

METHOD

We conducted a retrospective cohort study of patients with traumatic upper brachial plexus injury who underwent nerve transfer of the musculocutaneous nerve with either Ulnar nerve fascicles (SN) or both Ulnar and Median nerve fascicles (DN) for restoring elbow flexion. Patients with a minimum follow up of 18 months after surgery were included in this study. Elbow flexion strength was quantified using a force transducer and software module and the results were compared between the two groups.

RESULT

The median strength of elbow flexion was 14.3 Newton meter. In the SN group, the mean strength of elbow flexion was 5.4 ± 5 Nm, and for DN group it was 20.4 ± 9.9 Nm. Elbow flexion strength following DN procedure was significantly better when compared with SN.

CONCLUSION

The additional nerve transfer of median nerve fascicles with musculocutaneous nerve branch to the brachialis muscle does not add clinically obvious morbidity to the patient but has definite benefit as observed in this study. We advocate double fascicular nerve transfer for elbow flexion in upper brachial plexus injuries if the median and ulnar nerve functions are normal.

Ulnar and Median Fascicular Transfers for Elbow Flexion-Predicting Outcomes in a Heterogeneous Patient Group and Implications for Surgical Planning

Purpose: To measure the outcomes in patients undergoing nerve transfers for elbow flexion restoration, and compare patient outcomes based on the pre-operative fascicular transfer plan. Methods: Single surgeon series of 48 consecutive patients who underwent median and/or ulnar fascicular nerve transfers for elbow flexion restoration to treat palsies of the brachial plexus or musculocutaneous nerve. Outcomes measured were Medical Research Council (MRC) power grade, strength in kilograms, and time taken to recover function. Results: Overall, 96% of patients achieved MRC M4 or greater power. The subgroup who were planned for, and particularly those who then underwent, double as opposed to single fascicular transfer, had significantly better results. Conclusions: Overall results were excellent. Double fascicular transfers were superior, with no failures in this group. If pre-operatively a single fascicle transfer alone is planned due to a paucity of expendable donors, the predicted outcomes are worse and other treatment options should be considered.

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.

Trends in Nerve Transfer Procedures Among Board-Eligible Orthopedic Hand Surgeons

Purpose

Enthusiasm for peripheral nerve transfers increased over the past several years, but further studies are still needed to establish the role of these procedures in peripheral nerve reconstruction. The primary goal of this study was to describe the frequency of nerve transfer surgery among newly trained orthopedic surgeons.

Methods

We queried the American Board of Orthopaedic Surgery Part II case log database for all nerve reconstruction Current Procedural Terminology codes for examination years 2004 to 2018 for surgeries performed between 2003 and 2017. Information collected for each patient included examination year, year of surgery, surgeon fellowship training subspecialty, geographic region (as defined by the American Board of Orthopaedic Surgery Part II case log database), patient age, and patient sex.

Results

A total of 3,359 nerve reconstruction cases were logged by 1,542 individual candidates from examination years 2004 to 2018. Of the nerve reconstruction codes, 2.1% were nerve transfer codes. There was a statistically significant increase in the proportion of nerve transfer codes over the study period, from 0% of nerve reconstruction codes in examination years 2004 to 2006 to 4.1% of nerve reconstruction codes in examination years 2016 to 2018 (Z = –6.82; P < .001).

Conclusions

There has been an increase in the number of nerve transfer procedures relative to all nerve reconstruction codes for peripheral nerve conditions.

Clinical relevance

There is a modest but significant increase in nerve transfer procedures over time among newly trained orthopedic surgeons, which suggests the need for long-term outcomes studies for nerve transfers procedures performed in the setting of peripheral nerve conditions.

Safe level for harvesting for ulnar and median nerve transfers: a microanatomical and histological study

In selective ulnar and median nerve transfers, donor nerve fascicles should be harvested in an area where motor and sensory fascicles are intermingled to minimize motor or sensory deficits. We aimed to define such an area for ulnar and median nerve harvesting through microanatomical dissection and histology in 12 fresh adult cadaveric upper extremities. Anatomically, we studied the arrangement, localization, and histological features of fascicle groups in two nerves at eight segments of the upper arms. Histological sections were examined to confirm the findings of the anatomical dissections. We found that sensory and motor fascicles were mixed proximally to the third most distal segment of the ulnar nerve and to the fourth most distal segment of the median nerve. We conclude that harvesting a part of the ulnar or median nerve proximal to these levels minimizes donor nerve deficits.

Elbow Flexion Reconstruction in Brachial Plexus Avulsion Injuries – Results with Intercostal Nerve and Distal Nerve Transfers

Background: The neural surgical options for reconstruction of elbow flexion in brachial plexus injuries depend on the availability of nerve donors. In upper-type avulsion injuries, the ulnar or median nerves, when intact, are reliable intra-plexal donor nerves for transfers to the biceps muscle. In complete avulsion injuries, donors are limited to extra-plexal sources, such as intercostal nerves (ICNs).

Methods: We reviewed our results of ICN and partial distal nerve (ulnar or median) transfers for elbow flexion reconstruction in patients with brachial plexus avulsion injuries. The time taken for recovery of elbow flexion strength to M3 and the final motor outcome at 2 years were compared between both groups.

Results: 38 patients were included in this study. 27 had ICN transfers to the musculocutaneous nerve (MCN), 8 had partial ulnar nerve transfers and 3 had partial median nerve transfers to the MCN's biceps motor branch. The mean time interval from injury to surgery was 3.6 months. Recovery of elbow flexion was observed earlier in the distal nerve transfer group (p < 0.05). Overall, success rates were higher in patients with distal nerve transfers (100%), compared to ICN transfers (63%) at 2 years (p = 0.018). Patients with distal nerve transfers achieved a higher final median strength of M4.0 [Interquartile range (IQR) 3.5–4.5], compared to M3.5 (IQR 2.0–4.0) in the ICN group (p = 0.031). In the subgroup of patients with upper-type brachial plexus injuries, there were no significant differences in motor outcomes between the ICN versus distal nerve transfers group.

Conclusions: In our entire cohort, patients with distal nerve transfers had faster motor recovery and better elbow flexion power than patients with ICN transfers. In patients with partial brachial plexus injuries, outcomes of ICN transfers were not inferior to distal nerve transfers.

Finger sensory impairment after elbow flexion reconstruction using concomitant nerve transfer from the median and ulnar nerves

PURPOSE

Single and double fascicular nerve transfer using the ulnar or median nerve is performed to restore elbow flexion following injuries to the brachial plexus or nerve root. However, little is known regarding the postoperative changes involved in the sensory alteration of the hand after a single and double fascicular nerve transfer. We evaluated the sensory alteration of the hand in patients who underwent single and double fascicular nerve transfer for two years.

METHODS

A total of five patients that underwent single or double fascicular nerve transfer participated in this study. The injury mechanism was avulsion (n = 2), stretching (n = 1), open injury (n = 1), and compression (n = 1). The touch sensation of the index and the little fingers before surgery at 6 months, 1 year, and 2 years after nerve transfer was evaluated using the Semmes-Weinstein monofilaments test (SWM-t). Muscle strength of the elbow flexion and the wrist flexion was evaluated.

RESULTS

The touch sensation of the index finger at 24 months was equal to the preoperative evaluation. On the other hand, the touch sensation of the little finger at 24 months slightly improved compared to what it had been at the preoperative evaluation. Moreover, the median of the SWM-t score in the index and little finger at 24 months after surgery was beyond 3.61 that mean diminished light touch level.

CONCLUSIONS

The results of this study indicate that the touch sensory deficit of the index and little fingers persist for up to 2 years after nerve transfer.

Characterising cellular and molecular features of human peripheral nerve degeneration

Nerve regeneration is a key biological process in those recovering from neural trauma. From animal models it is known that the regenerative capacity of the peripheral nervous system (PNS) relies heavily on the remarkable ability of Schwann cells to undergo a phenotypic shift from a myelinating phenotype to one that is supportive of neural regeneration. In rodents, a great deal is known about the molecules that control this process, such as the transcription factors c-Jun and early growth response protein 2 (EGR2/KROX20), or mark the cells and cellular changes involved, including SOX10 and P75 neurotrophin receptor (p75NTR). However, ethical and practical challenges associated with studying human nerve injury have meant that little is known about human nerve regeneration.The present study addresses this issue, analysing 34 denervated and five healthy nerve samples from 27 patients retrieved during reconstructive nerve procedures. Using immunohistochemistry and Real-Time quantitative Polymerase Chain Reaction (RT-qPCR), the expression of SOX10, c-Jun, p75NTR and EGR2 was assessed in denervated samples and compared to healthy nerve. Nonparametric smoothing linear regression was implemented to better visualise trends in the expression of these markers across denervated samples.It was found, first, that two major genes associated with repair Schwann cells in rodents, c-Jun and p75NTR, are also up-regulated in acutely injured human nerves, while the myelin associated transcription factor EGR2 is down-regulated, observations that encourage the view that rodent models are relevant for learning about human nerve injury. Second, as in rodents, the expression of c-Jun and p75NTR declines during long-term denervation. In rodents, diminishing c-Jun and p75NTR levels mark the general deterioration of repair cells during chronic denervation, a process thought to be a major obstacle to effective nerve repair. The down-regulation of c-Jun and p75NTR reported here provides the first molecular evidence that also in humans, repair cells deteriorate during chronic denervation.

Can a Partially Injured Donor Nerve Restore Elbow Flexion in an Acute Brachial Plexus Injury in Rats?

BACKGROUND

Loss of elbow flexion commonly occurs following acute brachial plexus injury. The double fascicular transfer is often used in acute C5-C6 and C5-C7 root injuries, but is rarely applied in cases involving concomitant C8 or T1 root injury. The authors designed a rat model using varying severities of lower trunk injury to determine whether partial injury to the lower trunk affects nerve transfers for elbow flexion.

METHODS

There were four different rat groups in which 0, 25, 75, or 100 percent of the donor lower trunk remained intact. One-fourth of the cross-sectional area of the ulnar nerve was then transferred to the musculocutaneous nerve immediately. The authors assessed outcomes using a grooming test, muscle mass, retrograde labeling of sensory/motor neurons that regenerated axons, and immunohistochemical stain of regenerated axons.

RESULTS

Five months after nerve transfer, rats that underwent partial injury of the lower trunk fared significantly worse than the rats in whom the donor lower trunk remained 100 percent intact, but significantly better than the rats with 0 percent intact lower trunk. Rats with 25 or 75 percent of the lower trunk intact recovered equivalent function, at both the donor and recipient sites.

CONCLUSIONS

Although relatively weak compared with the 100 percent intact donor lower trunk group, the partially injured donor nerve was still functional; even though the nerve sustained a partial injury, the residual axons reinnervated the target muscles. The power of the muscles following either 25 percent or 75 percent injuries was equal after the recovery. Resorting to this approach may be useful in cases in which no alternatives are available.

Reconstruction of elbow flexion with a modified Oberlin procedure: A comparative study

INTRODUCTION

In upper brachial plexus injuries (C5-C6-C7), selective nerve transfers appear as a favourable technique. For this purpose, transfer of an ulnar nerve fascicle to the biceps motor branch (Oberlin's procedure) is often used. In this paper we present our modified Oberlin technique, as well as a comparison of this method with the classic Oberlin procedure.

MATERIALS AND METHODS

We present two groups of patients that where operated by two different surgeons. The first group, consisting of 16 patients was treated with the classic Oberlin procedure. The second group included 5 patients treated with a modified Oberlin procedure, where two fascicles from the ulnar nerve were transferred to both the motor branch of the biceps and the motor branch of the brachialis muscles.

RESULTS

In the last follow-up of the 16 patients from the first group with the classic Oberlin procedure, 15 patients (93.75%) had Medical Research Council (MRC) grade of biceps strength 4 and 1 patient (6.25%) had MRC grade 3, whereas in the group where the modified Oberlin procedure was used the muscle strength was very durable with 4 out of 5 the patients reached MRC grade of 4+ and one MRC grade of 4, and with a mean elbow strength at 5.4 kg (3-8 kg). No sensitivity or motor problems were encountered on the ulnar territories for both groups.

CONCLUSION

With the modified Oberlin technique, the median nerve is reserved and both elbow flexors are innervated. The results of this technique compare favourably with those of other methods. Thus, we propose using the double fascicle transfer from the ulnar nerve to both elbow flexors in order to restore a strong elbow flexion in patients with upper brachial plexus injuries.

Histologic Analysis of Sensory and Motor Axons in Branches of the Human Brachial Plexus

BACKGROUND

The topographic distribution through histologic analysis of motor and sensory axons within peripheral nerves at the brachial plexus level is not clearly defined, as there has previously been little need to appreciate this microanatomy. A desire to better understand the topography of fascicle groups developed with the introduction of targeted muscle reinnervation.

METHODS

Fourteen bilateral brachial plexus specimens from seven fresh human cadavers were harvested at the time of organ donation, and immunofluorescent staining of motor and sensory nerves with choline acetyltransferase and Neurofilament 200 was performed to determine whether a consistent somatotopic orientation exists at the brachial plexus level.

RESULTS

There was significant variability in the number of fascicles at the level of the brachial plexus. Qualitative analysis of choline acetyltransferase staining demonstrated that although motor axons tended to be grouped in clusters, there were high degrees of variability in somatotopic orientation across specimens. The radial nerve demonstrated the highest number of total myelinated axons, whereas the median nerve exhibited the greatest number of motor axons. The ulnar nerve contained only 13 percent motor axons, which was significantly lower than the median, radial, and musculocutaneous nerves.

CONCLUSIONS

There was no consistent somatotopic organization of motor and sensory axons of the mixed major nerves of the arm just distal to the brachial plexus, but clustering of motor axons may facilitate the splitting of nerves into primarily "motor" and "sensory" fascicles.