Nerve transfer to biceps muscle using a part of ulnar nerve for C5-C6 avulsion of the brachial plexus: anatomical study and report of four cases

From surgical problem to surgical solution - lessons and reflections

In this insightful and personal biographical article, Professor Bertelli recounts his journey from surgical problem to surgical solution with incredible detail. This was an invited article as part of the 2025 FESSH/JHSE Special Issue on 'Technology and Innovation'. He shares some of this thought process behind novel nerve transfer or examination techniques, built on solid anatomical foundations and careful patient observations. Professor Bertelli attributes his achievements to the influence of mentors, the importance of cadaveric dissections and long years of clinical experience.

Neurotization of the axillary nerve using a motor branch of the triceps brachii: Outcomes after a 3-to-15-year follow-up

PURPOSE

Axillary nerve neurotization using a motor branch of the triceps brachii has become a therapeutic option in the management of deltoid paralysis. The purpose of this study was to report the medium to long-term outcomes of this procedure.

MATERIAL AND METHODS

Twenty patients with a median age of 31 years (interquartile range - IQR, 29-53) were included in a single-operator retrospective study. A clinical evaluation was conducted, including the assessment of deltoid muscle strength using the British Medical Research Council grading system and a dynamometer with comparisons made between preoperative and postoperative outcomes.

RESULTS

The median follow-up period was 6 years (IQR, 5-11). At last follow-up, the median active abduction was 160° (IQR 60-160), and 85% of patients recovered at least M3 abduction force. No donor site deficits were identified.

DISCUSSION

The medium to long-term outcomes of the neurotization of a triceps brachii motor branch on the axillary nerve are comparable to the short-term outcomes.

LEVEL OF EVIDENCE

IV.

Modified double fascicular nerve transfer to restore elbow flexion in brachial plexus injuries - A series of 32 cases

Background

Elbow flexion restoration is one of the most important objectives of brachial plexus surgery in upper root injuries. Many authors have shown very good results with double fascicular nerve transfers and it has become the mainstay of nerve transfers for elbow flexion restoration. We present the results of a modified version of this double fascicular transfer.

Methods

A retrospective study of 32 patients who underwent the modified double fascicular nerve transfer(i.e median n to n to biceps and ulnar n to n to brachialis) was done. The average duration for delay in surgery from the time of injury was 5.6 months. The average age of the patients was 35.84. The average follow up of the patients was 39.3months.

Results

All patients had M0 or M1 power preoperatively. Eight patients had M3 power and 22 patients had M4 or M4+ power post operatively. Two patients did not recover meaningful elbow flexion. The results were similar to the original double fascicular nerve transfer for elbow flexion.

Conclusion

The modified version of the double fascicular nerve transfer is as reliable and produces similar results to the original double fascicular transfer. The theoretical advantages include the ease of doing the operation - (i) The n to biceps and median n are closer. (ii) The length of the n to brachialis allows it to be swung across the arm to reach the more posterior and medial ulnar nerve.

Functional outcomes following nerve transfers for shoulder and elbow reanimation in brachial plexus injuries: a 10-year retrospective study

Brachial plexus injuries are rare but highly disabling, with major implications for upper limb function and quality of life. Nerve transfers have emerged as a key reconstructive technique, particularly valuable in cases where primary repair or grafting is unfeasible or delayed. This retrospective study analysed functional outcomes following nerve transfers in 37 patients with brachial plexus injury. Motor recovery was assessed using the Medical Research Council scale. Patients were stratified by age, timing of surgery, injury severity, and type of nerve transfer performed. The majority of our cohort consisted of male adults, predominantly injured in motorcycle accidents, while pediatric cases were mostly due to obstetrical trauma. For shoulder reanimation, all patients received spinal accessory to suprascapular nerve transfer, with a subset also undergoing medial triceps branch of the radial nerve to axillary nerve transfer. These techniques resulted in 85.3% of patients achieving shoulder function recovery with M3 or M4 muscle strength, with combined procedures leading exclusively to M3 or M4 muscle strength. For elbow flexion restoration, surgical approaches included intercostal to musculocutaneous nerve transfer, ulnar and median fascicles to musculocutaneous nerve transfer, contralateral C7 to musculocutaneous nerve transfer with ulnar graft, and spinal accessory to musculocutaneous nerve transfer with sural nerve graft. Root grafting procedures using sural nerve grafts or nerve conduits were employed in three pediatric patients. Overall, 84.38% of patients achieved elbow flexion recovery with M3 or M4 muscle strength. These findings reinforce the utility of nerve transfers as a cornerstone in the surgical management of brachial plexus injury.

Spontaneous recovery of shoulder abduction in obstetric brachial plexus injury patients with less than horizontal abduction at 3 months

Abduction is one of the important shoulder functions that may be limited after an obstetric brachial plexus injury. We investigated the progress of spontaneous recovery of active abduction in a cohort of 68 conservatively treated obstetric brachial plexus injury patients without full recovery and with less than 90° abduction at 3 months. Of these 65 (96%) recovered at least 90° and 32 (47%) a full 170° of abduction. The median age of recovery to 90° was 9 months (IQR 7-12, range 5-65 and to 170° 24 months (IQR 12-36, range 5-84). The presence of active antigravity elbow flexion ≥90° at 4 months was not associated with recovery of abduction. The results suggest that most obstetric brachial plexus injury patients with isolated absent or slowly recovering shoulder movements recover at least 90° of abduction. In patients with absent or weak abduction, and otherwise satisfactory spontaneous recovery, surgical interventions should not be considered before 1 year of age.Level of evidence: III.

Benefits of Sensory Nerve Transfers and Risks of Using the Superficial Radial Nerve as a Donor

Nerve transfers have re-emerged in the past several decades as a powerful tool for restoration of neurological function and are an essential part of peripheral nerve surgical practice. There is extensive literature describing outcomes from nerve transfers for the restoration of motor nerve function and describing the complication profile. Recently, interest and use of nerve transfers for restoration of sensation has increased. In this review, we highlight the limitations of the current literature on outcomes from sensory nerve transfers and showcase potential complications from their use, particularly related to use of the superficial branch of the radial nerve as a donor sensory nerve.

Treatment of Complete Brachial Plexus Injuries Using Double Free Muscle Transfer

PURPOSE

The purpose of this study was to examine the surgical outcomes of double free muscle transfer (DFMT) performed in patients with complete brachial plexus injury (BPI).

METHODS

We retrospectively analyzed the outcomes of DFMT for 12 patients with complete BPI who were followed up for more than 2 years after the final muscle transplantation. Their mean age was 29 years (range, 18-41). Three patients underwent contralateral C7 nerve root transfer before the DFMT. The range of motion (ROM) of the shoulder, elbow, and fingers was measured. Patient-reported outcome measures, including Disability of the Shoulder, Arm, and Hand (DASH) scores and visual analog scale (VAS) scores for pain, were also examined.

RESULTS

The mean shoulder ROM against gravity was 22° ± 8° in abduction and 33° ± 5° in flexion. Seven patients underwent phrenic nerve (PhN) transfer to the suprascapular nerves, and five exhibited asymptomatic lung impairment on spirography more than 2 years after PhN transfer. The mean elbow ROM against gravity was 111° ± 9° in flexion and -32° ± 7° in extension. All patients obtained elbow flexion >90° against a 0.5-kg weight. All patients obtained touch sensation and two recognized warm and cold sensations in the affected palm. The mean total active motion of the affected fingers was 44° ± 11°. All patients exhibited hook function of the hands. The mean preoperative and postoperative DASH scores were 70.3 ± 13.4 and 51.8 ± 15.9, respectively. The mean pain VAS score was 28 ± 31 at the final follow-up.

CONCLUSIONS

Double free muscle transfer provided patients with complete brachial plexus palsy with good elbow flexion and hand hook functions.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

The recovery and independence of elbow flexion and forearm supination after Oberlin II transfer in brachial plexus injuries: a long term follows up study

PURPOSE

The Oberlin II double fascicular nerve transfer has been evaluated extensively for objective outcomes for elbow flexion in brachial plexus injuries (BPI). However, there is limited information available on the recovery pattern of supination and patient-reported activity in the long-term. Our study aimed to assess the functional results with a minimum of five years of follow-up.

METHODS

We evaluated patients with a minimum of five years after the Oberlin II procedure for post-traumatic BPI. They were evaluated using MRC grading, range of active movements, QuickDASH score and activity to check elbow flexion and forearm supination independent of finger and wrist flexion.

RESULTS

18 out of 26 patients responded with a mean follow-up of 79.4 months (range: 61-98). 16 (88.9%) (p < 0.000) patients recovered to achieve active elbow flexion and forearm supination of either MRC grade 3 power or more. The average range of active elbow flexion was 113.9° (range: 0-140°) and active supination was 67.8° (0-90°). Patients who achieved grade 3 flexion or higher were found to regain supination after a delay. The recovery continues even after two years of surgery. The mean QuickDASH score was 21.8 (range: 2.3-63.6). There's a significant inverse correlation between QuickDASH with both flexion and supination (p < .001 and < 0.05). 15 patients (83.3%) could demonstrate a dissociation of elbow and forearm movements from digital and wrist movements.

CONCLUSION

Our study demonstrated reliable functional results with independent elbow flexion, forearm supination and acceptable patient-reported outcomes for Oberlin II procedure in BPI.

Research trends and hotspots in the surgical treatment of peripheral nerve injuries of the upper limb from 2000 to 2024: a bibliometric visualization study

Purpose

Surgical treatment plays a crucial role in the management of peripheral nerve injuries of the upper limb, but little bibliometric analysis has been conducted on it. This study was aimed to examine the global trends and hotspots in the field of Peripheral nerve injuries of the upper limb.

Methods

Publications on the surgical treatment of peripheral nerve injuries of the upper limb in the Web of Science database were collected between 2000 to 2024. CiteSpace and VOSviewer software was applied to visualize and analyze publications, countries, institutions, journals, authors, references, and keywords.

Results

A total of 751 articles were collected, the most active countries in this field were the United States and China. The authors with the most publications were Mackinnon, Susan E from the United States, and Xu WD and Gu YD from China. JOURNAL OF HAND SURGERY AMERICAN VOLUME was the journal with the most published. Based on keywords, the current research hotspots primarily revolved around nerve transfer, brachial plexus and reconstruction.

Conclusion

The results of this bibliometric study provide clinical trends and hotspots in the surgical treatment of peripheral nerve injuries of the upper limb over the past 24 years, which may help researchers to identify clinical trends and explore new treatment in the field of peripheral nerve injuries.

Impact of Surgery Timing on Outcomes After Nerve Transfer to Restore Elbow Flexion

Background

Nerve reconstruction following brachial plexus injury (BPI) is a time-sensitive procedure, and surgical delay may negatively impact muscle reinnervation and outcomes. This study investigated the impact of surgical timing on elbow flexion strength in patients with BPI undergoing nerve transfer to restore elbow flexion.

Methods

Following PRISMA guidelines, MEDLINE, Embase, and the Cochrane Library databases were systematically searched. English-language studies investigating the single fascicular transfer (SFT) or double fascicular transfer (DFT) to restore elbow flexion in BPI were included. Data were analyzed to identify the predictors of elbow flexion strength: surgery timing, age, injury level, and SFT versus DFT.

Results

The literature search identified 1051 articles. Studies (n = 31) reporting data of individual patients who underwent SFT (n = 341) or DFT (n = 67) were included; the mean age was 29.6 ± 11.2 years, time from injury to surgery was 6.5 ± 5.0 months, and follow-up was 27.1 ± 24.3 months. Good elbow flexion strength was found: Medical Research Council grade greater than or equal to 3 in 352 (86.3%) and Medical Research Council grade greater than or equal to 4 in 288 (70.6%). In the adjusted analysis, poorer motor recovery was associated with increased age (P = 0.02), surgical delay (P < 0.0001), C5-7 injuries (P < 0.01), and pan-plexus injuries (P < 0.0001). A 32% reduction in the odds of favorable motor recovery was observed with a 3-month delay to surgery. Patients who had a nerve transfer 6 months or earlier from injury had 2.4 times the odds of favorable motor recovery (P < 0.001).

Conclusions

SFT and DFT provide excellent elbow flexion strength in the majority of patients. Following nerve transfers in individuals with BPI, poorer motor recovery was observed with each 3-month delay to surgery.

Comparing the long-term results of Oberlin II versus intercostal neurotization for elbowflexion restoration (Prospective study)

BACKGROUND

Restoring elbow flexion following brachial plexus injury (BPI) is essential for improving arm function and quality of life in adults. This study aimed to compare the efficacy of Oberlin II and intercostal nerve (ICN) neurotization techniques for restoring elbow flexion in adults with upper and middle trunk brachial plexus palsy.

METHODS

This prospective study included 36 patients aged 18 to 50 years with traumatic upper and middle trunk brachial plexus palsy. The patients were divided into two groups: Group A consisted of 19 patients who underwent the Oberlin II procedure, while Group B included 17 patients treated with ICN neurotization. All patients were followed for at least 60 months.

RESULTS

Muscle reactivation occurred significantly earlier in the Oberlin II group compared to the ICN neurotization group (P = 0.012). Muscle strength grading also showed significant differences, with a higher proportion of patients achieving grade 4 and 4+ strength in the Oberlin II group compared to the ICN neurotization group (P = 0.041).

CONCLUSIONS

The Oberlin II neurotization technique demonstrated superior efficacy in restoring elbow flexion following BPI compared to ICN neurotization. It resulted in earlier muscle reactivation and higher levels of muscle strength, with a greater proportion of patients achieving grades 4 and 4+ strength.

Outcomes of Oberlin Transfer in Elderly Patients: A Case Series

OBJECTIVE

A case series analysis was performed of upper brachial plexus injuries (BPIs) from low-impact trauma in patients ≥60 years old to assess the effectiveness of nerve transfers, particularly the Oberlin technique, in restoring elbow flexion and to refine clinical decision making for managing traumatic BPIs in this age group.

METHODS

Between 2013 and 2024, 11 patients aged 60-72 with traumatic upper BPIs underwent Oberlin technique for elbow flexion; all were evaluated with consistent postsurgical criteria.

RESULTS

Trauma mechanisms included falls (55%), direct trauma (27%), knife wounds (9%), and stretching (9%), with no high-impact trauma cases. Injuries predominantly affected the right side (55%). Elbow flexion strength was assessed using the British Medical Research Council scale. Positive Tinel sign was present in 73% of patients, all reporting pain ranging from mild to severe. At 1 year postsurgery, 64% achieved M4 elbow flexion, 27% achieved M3, and 9% achieved M1 after 4 months. Patients >65 who received surgery within 6 months of injury showed better outcomes except for 1 case. No ulnar nerve deficits were observed. Following surgery, 36% experienced no pain, whereas 64% reported mild pain. Additionally, 64% underwent further nerve transfers to restore shoulder function (spinal accessory nerve to suprascapular nerve), and 18% underwent the Somsakprocedure for deltoid function.

CONCLUSIONS

Positive outcomes were achieved with the Oberlin technique in patients >60 with upper BPIs from low-energy trauma. However, delayed surgery, significant atrophy, and low testosterone levels may affect results. Evaluation of each patient's medical history is crucial before performing this procedure.

Triple nerve transfer for restoration of elbow flexion in C5-C6 traumatic brachial plexus injuries

We retrospectively reviewed the outcome of triple nerve transfer, including reinnervation of brachioradialis and double nerve transfer surgery in C5-C6 traumatic brachial plexus injuries.Level of evidence: IV.

Global trends in surgical approach to neonatal brachial plexus palsy: a systematic review

Background

We analyzed trends in age at surgery and surgical approach over time and geography.

Methods

We performed a systematic review according to PRISMA-IPD guidelines to include individual patient data. Collected data included age at surgery, location of surgery, and surgical approach. The surgical approach was independently categorized as the exploration of the brachial plexus (EBP) or nerve transfer without root exploration (NTwoRE). EBP was defined as exploring the brachial plexus in the supraclavicular fossa and applying a choice of coaptation procedures. NTwoRE included those sourcing donor nerves from, or entirely occurring outside of the plexus without exploring the root of the brachial plexus.

Results

Regression analysis of age at surgery 1985-2020 showed that age at BPBI surgery is rising (p < 0.05). Surgery was performed at a younger age in patients from Europe (7.06 ± 7.77 months) and Asia (7.58 ± 5.33 months) than those from North America (10.44 ± 5.01 months) and South America (14.71 ± 4.53 months) (p < 0.05). NTwoRE was more common in North America (37%) and least common in Europe (12%). Age at EBP was 7.2 ± 5.77 months, and age at NTwoRE was 15.85 ± 13.18 months (p < 0.05). The incidence of NTwoRE is increasing time.

Conclusions

Age at NBPP surgery is increasing over time. Regional differences exist in age at NBPP surgery. Approaches to NBPP surgery that avoid exploration of BP roots are becoming more popular. Age at EBP is lower than age at NTwoRE.

Cortical Neurotransmitters Measured by Magnetic Resonance Spectroscopy Change Following Traumatic Brachial Plexus Injury

Introduction  GABA (γ-aminobutyric acid) is the major inhibitory neurotransmitter in the brain. In response to injury within the central nervous system, GABA promotes cortical plasticity and represents a potential pharmacological target to improve functional recovery. However, it is unclear how GABA changes in the brain after traumatic brachial plexus injuries (tBPIs) which represents the rationale for this pilot study. Methods  We serially scanned seven males (mean age 42 years [SD 19] without head injury) up to 19 months after tBPIs. T1-weighted images (1-mm isotropic resolution) and J-edited spectra (MEscher-GArwood Point RESolved Spectroscopy [MEGA-PRESS], TE 68 ms, TR 2,000 ms, 2 cm isotropic voxels) were acquired using a MAGNETOM Prisma 3T (Siemens Healthcare, Erlangen, Germany). Data were analyzed in jMRUI blind to clinical information to quantify GABA, creatine plus phosphocreatine (Cr), and N-acetylaspartate (NAA) concentrations. Additionally, gray matter and white matter proportions were assessed using SPECTRIM software. Interhemispheric means were compared using linear methods. Confidence intervals (CIs) were generated to the 95% level. Results  Within weeks of injury, the hemisphere representing the injured upper limb had a significantly lower GABA:NAA ratio (mean difference 0.23 [CI 0.06-0.40]) and GABA:Cr ratio (mean difference 0.75 [CI 0.24-1.25]) than the uninjured side. There were no interhemispheric differences in NAA:Cr. By 12 months post-injury, interhemispheric differences in metabolite concentrations equalized. There was no difference in the proportion of gray matter, white matter, or cerebrospinal fluid between the injured and uninjured hemispheres. Conclusion  After brachial plexus injuries, there are interhemispheric differences in GABA concentrations within the sensory and motor cortex. This represents a potential pharmacological target that warrants further investigation.

Results of the Nerve Transfers and Secondary Procedures to Restore Shoulder and Elbow Function in Traumatic Upper Brachial Plexus Palsy

Background: Damage to the upper trunk of the brachial plexus, often caused by high-energy trauma, leads to significant functional impairment of the upper limb. This injury primarily affects the C5 and C6 roots, resulting in paralysis of muscles critical for shoulder and elbow function. If spontaneous nerve regeneration does not occur within 3-6 months post-injury, surgical intervention, including nerve transfers, is recommended to restore function. Methods: This study evaluates long-term outcomes of nerve transfer surgeries performed between 2013 and 2023 on 16 adult patients with post-traumatic brachial plexus injuries. The most common cause of injury was motorcycle accidents. Nerve transfers targeted shoulder and elbow function restoration, including transfer of the accessory nerve to the suprascapular nerve, the radial nerve branch to the long or medial head of the triceps brachii to the axillary nerve, or the transfer of motor fascicles of the ulnar and median nerves (double Oberlin) to the brachialis and biceps brachii motor nerves. Results: Postoperative results showed varying degrees of functional recovery. In the shoulder, most patients achieved stabilization and partial restoration of active movement, with average flexion up to 92° and abduction up to 78°. In the elbow, full flexion with M4 strength was achieved in 64% of patients. In both the shoulder and the elbow, double nerve transfers yield better long-term outcomes than single transfers. Secondary procedures, such as tendon transfers, were required in some cases to improve limb strength. Conclusions: The study concludes that nerve transfers offer reliable outcomes in restoring upper limb function, although additional surgeries may be necessary in certain cases.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL RELEVANCE

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

Review of Outcomes After Peripheral Nerve Transfers for Motor Nerve Injury in the Upper Extremity

BACKGROUND

Modern nerve-to-nerve transfers are a significant advancement in peripheral nerve surgery. Nerve transfers involve transferring donor nerves or branches to recipient nerves close to the motor end unit, leading to earlier reinnervation and preservation of the musculotendinous units in proximal nerve injuries. After nerve reinnervation, function may be superior to traditional tendon transfer techniques in terms of strength and independent motion. Nerve transfer surgery has emerged as a promising treatment option for many cases of nerve injury that were previously expected to result in poor outcomes, such as proximal injuries, long nerve gaps, or unavailability of the proximal injured segment.

METHODS

A review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Publications that focused on upper extremity nerve transfers were included, and functional motor and sensory recovery was analyzed. Technique reports, case reports, brachial plexus injuries, and reports on multiple nerve injuries were excluded.

RESULTS

A total of 48 relevant articles were identified with search criteria, and we discuss functional outcomes on nerve transfers for ulnar nerve injury, musculocutaneous nerve injury, median nerve injury, and radial nerve injury that met inclusion criteria.

CONCLUSIONS

Nerve transfers are an option for restoring hand and forearm function in patients with peripheral nerve injuries adversely affecting their ability to function. The literature demonstrates positive functional outcomes after nerve transfer operations, and thus, the utility and variations have increased. We aim to provide an overview of the outcomes of current nerve transfer techniques for ulnar, radial, median, and musculocutaneous acquired/traumatic mononeuropathies in the hand and upper extremity.

Direct Repair of Ruptured Nerve Stump to Middle Trunk for Restoration of Extrinsic Finger Extension in Total Brachial Plexus Injuries

BACKGROUND

Attempts to restore independent hand function in total brachial plexus injuries (TBPIs) have often failed due to inconsistent results of finger extension reconstruction. An innovative technique is described to achieve this effect by direct neurorrhaphy of residual (ruptured) roots with the middle trunk.

METHODS

Direct coaptation of the ruptured roots to the middle trunk and, simultaneously, transferring the anterior division of the middle trunk to the posterior division of the lower trunk was performed in 64 patients with TBPI. The return of extension of the elbow, wrist, and fingers was monitored.

RESULTS

Excellent and good muscle strength of finger extension were noted in 45.3% of cases. The patients were divided into group A (>32 years) and group B (≤32 years) according to receiver operating characteristic curve analysis. The difference of excellent and good rates of finger and wrist extension muscle strengths between the 2 groups was statistically significant (χ 2 = 4.635, P = 0.031; χ 2 = 6.615, P = 0.010).

CONCLUSIONS

Direct neurorrhaphy of ruptured nerve root stumps with the middle trunk could achieve satisfactory results for finger extension in TBPI for patients ≤32 years old. Long nerve defects (4 to 6.5 cm) could be overcome by freeing the nerve and adducting the arm against the trunk.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Anatomical study of single incision contralateral C7 nerve transfer through subdural pathway

Objective

To explore the feasibility of single incision C7 nerve transfer surgery through the subarachnoid pathway on the healthy side through anatomical research.

Method

Four fresh frozen cadaver specimens were used for the study. Observe and measure the length of C7 nerve root fibers. Divide the front root into 3 bundles and the rear root into 5 bundles.

Result

The C7 nerve has a filamentous structure, arranged symmetrically on both sides, and the length of the root fibers gradually shortens from top to bottom. The length of the left anterior root decreased from (12.25 ± 0.68) mm to (9.75 ± 1.40) mm, the length of the right anterior root decreased from (12.95 ± 1.49) mm to (10.00 ± 2.00) mm, the length of the left posterior root decreased from (15.63 ± 1.55) mm to (12.38 ± 0.71) mm, and the length of the right posterior root decreased from (15.48 ± 1.37) mm to (12.30 ± 0.90) mm. The distance from the exit of the C7 nerve from the dura mater to the fusion site in 4 specimens was (10.98 ± 1.21) mm on the left and (10.98 ± 1.391) mm on the right. All four specimens have completed nerve bundle anastomosis.

Conclusion

From an anatomical perspective, it is feasible to anastomose the healthy side C7 nerve with the affected side root fibers in the dorsal bundle of the spinal cord after cutting off the dura mater.

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.

Proximal and Distal Nerve Transfers in the Management of Brachial Plexus Injuries

Nerve transfer surgery utilizes the redundant and synergistic innervation of intact muscle groups to rehabilitate motor function. This is achieved by transferring functional nerves or fascicles to damaged nerves near the target area, thereby reducing the reinnervation distance and time. The techniques encompass both proximal and distal nerve transfers, customized according to the specific injury. Successful nerve transfer hinges on accurate diagnosis, innovative surgical approaches, and the judicious choice of donor nerves to maximize functional restoration. This study explores nerve transfer strategies and their integration with other procedures, emphasizing their importance in enhancing outcomes in brachial plexus injury management.

Single versus double fascicular transfer for brachial plexus injuries: a systematic review and meta-analysis with meta-regression

The primary objective of this review was to assess whether double fascicular transfer has superior outcomes compared with single fascicular transfer for reanimation of elbow flexion. In total, 58 studies including 1388 patients (mean age 29 years [SD 8]) were included. Subgroup analysis comparing the severity of brachial plexus injury (C5-C6, C5-C7, C5-C8) showed no significant difference in the recovery of MRC grade 3 and 4. The aggregated mean Disabilities of Arm, Shoulder and Hand score was 38 for the single fascicular transfer group and 27 for the double fascicular transfer group. Meta-regression controlling for level of injury showed that double fascicular transfer and C5-C6 injury were significant predictors of achieving MRC grade 3, while double fascicular transfer and shorter duration of surgical delay were significant predictors of achieving MRC grade 4. When controlling for the level of injury, double fascicular transfer is associated with a greater likelihood of achieving MRC grade 3 and 4 compared to single fascicular transfer. Overall donor site morbidity was not significantly different between single fascicular transfer and double fascicular transfer.

A Multicenter Validation of a Novel Prediction Model for Elbow Flexion Recovery after Nerve Transfer Surgery in Brachial Plexus Injuries

Background

Nerve transfer surgery for brachial plexus injuries exhibits variable success rates, potentially resulting in prolonged limb dysfunction for more than 2 years. A proposed prediction model has been developed to predict the unsuccessful recovery of elbow flexion after the surgery. The model consisted of six variables, namely body mass index 23 kg/m2 or more, smoking, total arm type, donor nerve, ipsilateral upper extremity fracture, and ipsilateral vascular injury. This study aimed to assess the external validity of the model for wider applicability.

Methods

This retrospective analysis examined the medical records of 213 eligible patients with traumatic brachial plexus injuries who underwent surgery at two referral centers between July 2008 and June 2022. The prediction model was applied to estimate recovery failure probability, which was compared with the observed outcomes for each patient. Both the original and simplified models were validated for discrimination and calibration using metrics including c-statistic, Hosmer-Lemeshow goodness-of-fit test, calibration plot, calibration slope, and intercept.

Results

Thirty-two percent of patients experienced unsuccessful elbow flexion recovery. Both the original and simplified models demonstrated good discrimination (c-statistics: 0.748 and 0.759, respectively). The Hosmer-Lemeshow test revealed strong agreement between predicted and observed probabilities for both models (P = 0.66 and P = 0.92, respectively). The calibration plot exhibited good agreement, with a calibration slope of 0.928 and an intercept of 0.377.

Conclusions

The prediction model showed strong external validation, confirming its clinical value. High-risk patients should be educated on the risks and benefits of nerve transfer surgery and consider alternative treatments such as primary free functioning muscle transfer.

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.

Ten Myths in Nerve Surgery

Background

Surgical innovation has provided new options for the management of complex peripheral nerve injuries, generating renewed interest in this field. Historic literature may be misinterpreted or misquoted, or create dogma, which is perpetuated in teaching, research publications, and clinical practice. The management of peripheral nerve injuries is based on complex decision-making, with potential lifelong ramifications for patients incorrectly receiving an expectant or surgical management plan.

Methods

This article includes opinion from expert leaders in the field of peripheral nerve surgery and questions some of the current assumptions and preconceptions around nerve surgery based on clinical evidence. There was extensive debate regarding the contents of the final article, and the different opinions expressed represent the uncertainty in this field and the differing levels of confidence in available published evidence.

Results

Individual practices vary and, therefore, absolute consensus is impossible to achieve. The work is presented as 10 myths which are assessed using both historical and emerging evidence, and areas of uncertainty are discussed.

Conclusions

It is important to learn lessons from the past, and scholars of history bear the task of ensuring references are accurately quoted. Expunging myths will enhance care for patients, focus research efforts, and expand on the surgical possibilities within this specialty.

Contemporary Approaches to Peripheral Nerve Surgery

"State of the Art" Learning Objectives: This manuscript serves to provide the reader with a general overview of the contemporary approaches to peripheral nerve reconstruction as the field has undergone considerable advancement over the last 3 decades. The learning objectives are as follows: To provide the reader with a brief history of peripheral nerve surgery and some of the landmark developments that allow for current peripheral nerve care practices.To outline the considerations and management options for the care of patients with brachial plexopathy, spinal cord injury, and lower extremity peripheral nerve injury.Highlight contemporary surgical techniques to address terminal neuroma and phantom limb pain.Review progressive and future procedures in peripheral nerve care, such as supercharge end-to-side nerve transfers.Discuss rehabilitation techniques for peripheral nerve care.

The prerequisites and clinical outcomes of ipsilateral C7 nerve root transfer to the upper trunk for adult C5-C6 brachial plexus injuries

PURPOSE

Although ipsilateral C7 nerve transfer is used for the treatment of C5-C6 brachial plexus injuries, accurately evaluating the functional quality of the donor nerve (ipsilateral C7 nerve root) is difficult, especially when the C7 nerve root is slightly injured. The purpose of this study was to determine the indicators to evaluate the quality of the ipsilateral C7 nerve and assess the clinical outcomes of this procedure.

METHODS

This study employed the following three indicators to assess the quality of the ipsilateral C7 nerve: (1) the muscle strength and electrophysiological status of the latissimus dorsi, triceps brachii, and extensor digitorum communis; (2) the sensibility of the radial three digits, especially the index finger; and (3) the intraoperative appearance, feel and electrophysiological status of the ipsilateral C7 nerve root. Transfer of the ipsilateral C7 nerve root to the upper trunk was implemented only when the following three tests were conducted, the criteria were met, and the clinical outcomes were assessed in eight patients with C5-C6 brachial plexus injuries.

RESULTS

Patients were followed-up for an average of 90 ± 42 months. At the final follow-up, all eight patients achieved recovery of elbow flexion, with five and three patients scoring M4 and M3, respectively, according to the Medical Research Council scoring. The shoulder abduction range of motor recovery averaged 86 ± 47° (range, 30°-170°), whereas the shoulder external rotation averaged 51 ± 26° (range, 15°-90°).

CONCLUSION

Ipsilateral C7 nerve transfer is a reliable and effective option for the functional reconstruction of the shoulder and elbow after C5-C6 brachial plexus injuries when the three prerequisites are met.

Upper Extremity Nerve Transfers for Treatment of Nerve Injury After Cervical Spine Surgery: A Single-Center Retrospective Review

PURPOSE

Nerve transfers to restore or augment function after spinal cord injury is an expanding field. There is a paucity of information, however, on the use of nerve transfers for patients having undergone spine surgery. The incidence of neurologic deficit after spine surgery is rare but extremely debilitating. The purpose of this study was to describe the functional benefit after upper extremity nerve transfers in the setting of nerve injury after cervical spine surgery.

METHODS

A single-center retrospective review of all patients who underwent nerve transfers after cervical spine surgery was completed. Patient demographics, injury features, spine surgery procedure, nerve conduction and electromyography study results, time to referral to nerve surgeon, time to surgery, surgical technique and number of nerve transfers performed, complications, postoperative muscle testing, and subjective outcomes were reviewed.

RESULTS

Fourteen nerve transfers were performed in 6 patients after cervical spine surgery. Nerve transfer procedures consisted of a transfer between a median nerve branch of flexor digitorum superficialis into a biceps nerve branch, an ulnar nerve branch of flexor carpi ulnaris into a brachialis nerve branch, a radial nerve branch of triceps muscle into the axillary nerve, and the anterior interosseous nerve into the ulnar motor nerve. Average patient age was 55 years; all patients were male and underwent surgery on their left upper extremity. Average referral time was 7 months, average time to nerve transfer was 9 months, and average follow-up was 21 months. Average preoperative muscle grading was 0.9 of 5, and average postoperative muscle grading was 4.1 of 5 ( P < 0.00001).

CONCLUSIONS

Upper extremity peripheral nerve transfers can significantly help patients regain muscle function from deficits secondary to cervical spine procedures. The morbidity of the nerve transfers is minimal with measurable improvements in muscle function.

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.

Positive effect of ulnar nerve fascicle transfer to musculocutaneous nerve seeded with allogeneic adipose tissue derived stem cells on nerve regeneration for repairing upper brachial plexus injury in a rat model: A preliminary study

BACKGROUND

Traumatic peripheral nerve injury, with an annual incidence reported to be approximately 13-23 per 100,000 people, is a serious clinical condition that can often lead to significant functional impairment and permanent disability. Although nerve transfer has become increasingly popular in the treatment of brachial plexus injuries, satisfactory results cannot be obtained even with total nerve root transfer, especially after serious injuries. To overcome this problem, we hypothesize that the application of stem cells in conjunction with nerve transfer procedures may be a viable alternative to more aggressive treatments that do not result in adequate improvement. Similarly, some preliminary studies have shown that adipose stem cells combined with acellular nerve allograft provide promising results in the repair of brachial plexus injury. The purpose of this study was to assess the efficacy of combining adipose-derived stem cells with nerve transfer procedure in a rat brachial plexus injury model.

METHODS

Twenty female Wistar rats weighing 300-350 g and aged 8-10 weeks were randomly divided into two groups: a nerve transfer group (NT group) and a nerve transfer combined adipose stem cell group (NT and ASC group). The upper brachial plexus injury model was established by gently avulsing the C5-C6 roots from the spinal cord with microforceps. A nerve transfer from the ulnar nerve to the musculocutaneous nerve (Oberlin procedure) was performed with or without seeded allogeneic adipose tissue-derived stem cells. Adipose tissue-derived stem cells at a rate of 2 × 106 cells were injected locally to the surface of the nerve transfer area with a 23-gauge needle. Immunohistochemistry (S100 and PGP 9.5 antibodies) and electrophysiological data were used to evaluate the effect of nerve repair 12 weeks after surgery.

RESULTS

The mean latency was significantly longer in the NT group (2.0 ± 0.0 ms, 95% CI: 1.96-2.06) than in the NT and ASC group (1.7 ± 0.0 ms, 95% CI: 1.7-1.7) (p < .001). The mean peak value was higher in the NT group (1.7 ± 0.0 mV, 95% CI: 1.7-1.7) than in the NT and ASC group (1.7 ± 0.3 mV, 95% CI: 1.6-1.9) with no significant difference (p = .61). Although S100 and PGP 9.5 positive areas were observed in higher amounts in the NT and ASC group compared to the NT group, the differences were not statistically significant (p = .26 and .08, respectively).

CONCLUSIONS

This study conducted on rats provides preliminary evidence that adipose-derived stem cells may have a positive effect on nerve transfer for the treatment of brachial plexus injury. Further studies with larger sample sizes and longer follow-up periods are needed to confirm these findings.

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.

History of peripheral nerve injuries

This article reviews the history of peripheral nerve (PN) injuries and successive advances in their management by notable pioneers, an interesting topic that I chose for my Doctoral Thesis in 1990 in Madrid. Mentioning all their names and contributions is an obligatory tribute, and I offer my sincere apologies for inevitably leaving a few out. For half a century I have witnessed microsurgery advances, and also experienced frequent failures in my practice with the use of new techniques; a testimony that we are very far from achieving the 'Holy Grail' of complete PN recovery for these injuries. Our experience is often like a pendulum, from nihilism to optimism and vice versa. Many factors influence the results of PN repair. Fortunately, microsurgery has been a breakthrough but, too often, emergency surgery is carried out by surgeons without enough tools and experience, both very important factors in this field.

Adult traumatic brachial plexus injuries: advances and current updates

Nerve grafting, tendon transfer and joint fusion are routinely used to improve the upper limb function in patients with brachial plexus palsies. Newer techniques have been developed that provide additional options for reconstruction. Nerve transfer is a tool for restoring upper limb function in total root avulsions where nerve grafting is not possible. In partial brachial plexus injuries, nerve transfers can greatly improve shoulder, elbow, wrist and hand function. Intraoperative electrical stimulation can be used to diagnose precisely which nerve is injured and to choose which nerve fascicles should be transferred. Finally, measuring the postoperative outcome can improve the evaluation of our techniques. The aim of this article was to present the current techniques used to treat patients with brachial plexus injury.

Peripheral nerve transfers for dysfunctions in central nervous system injuries: a systematic review

BACKGROUND

The review highlights recent advancements and innovative uses of nerve transfer surgery in treating dysfunctions caused by central nervous system (CNS) injuries, with a particular focus on spinal cord injury (SCI), stroke, traumatic brain injury, and cerebral palsy.

METHODS

A comprehensive literature search was conducted regarding nerve transfer for restoring sensorimotor functions and bladder control following injuries of spinal cord and brain, across PubMed and Web of Science from January 1920 to May 2023. Two independent reviewers undertook article selection, data extraction, and risk of bias assessment with several appraisal tools, including the Cochrane Risk of Bias Tool, the JBI Critical Appraisal Checklist, and SYRCLE's ROB tool. The study protocol has been registered and reported following PRISMA and AMSTAR guidelines.

RESULTS

Nine hundred six articles were retrieved, of which 35 studies were included (20 on SCI and 15 on brain injury), with 371 participants included in the surgery group and 192 in the control group. These articles were mostly low-risk, with methodological concerns in study types, highlighting the complexity and diversity. For SCI, the strength of target muscle increased by 3.13 of Medical Research Council grade, and the residual urine volume reduced by more than 100 ml in 15 of 20 patients. For unilateral brain injury, the Fugl-Myer motor assessment (FMA) improved 15.14-26 score in upper extremity compared to 2.35-26 in the control group. The overall reduction in Modified Ashworth score was 0.76-2 compared to 0-1 in the control group. Range of motion (ROM) increased 18.4-80° in elbow, 20.4-110° in wrist and 18.8-130° in forearm, while ROM changed -4.03°-20° in elbow, -2.08°-10° in wrist, -2.26°-20° in forearm in the control group. The improvement of FMA in lower extremity was 9 score compared to the presurgery.

CONCLUSION

Nerve transfer generally improves sensorimotor functions in paralyzed limbs and bladder control following CNS injury. The technique effectively creates a 'bypass' for signals and facilitates functional recovery by leveraging neural plasticity. It suggested a future of surgery, neurorehabilitation and robotic-assistants converge to improve outcomes for CNS.

Outcomes of surgically managed adult traumatic brachial plexus injuries in an upper-middle-income country

Background

Traumatic brachial plexus injuries (TBPIs) are debilitating and complex to treat. The last five decades have seen advances in surgical management, and consequently improved functional outcomes in patients with these injuries. There is limited data available describing the outcomes of surgically managed TBPIs within the South African context. This study aimed to identify the common causes of injury, injury characteristics, and functional outcomes of surgically managed patients with TBPIs.

Methods

We conducted a retrospective chart review of all adult patients that underwent surgery for TBPIs over a period of ten years at a specialised hand unit in South Africa. The minimum follow-up period was one year. Patient demographic details, injury characteristics and functional outcomes were collected. Statistical analysis was performed to determine factors associated with functional outcomes. A good functional outcome for recovery was defined as a Medical Research Council (MRC) grade of three or more for the affected elements of the plexus at the most recent follow-up.

Results

Forty-seven patients of median age 32 years were included in the final analysis. Most patients were male (87.2 %). The majority of patients were injured in motor vehicle accidents (MVAs) or from penetrating stab wounds (48.9 % and 38.3 % respectively). The median pre-operative MRC grade of the affected elements of the brachial plexus was 0.0, and post-operatively was 2.0. Fourteen patients (14 of 47, 29.8 %) had a good outcome and 33 had a poor outcome (33 of 47, 70.2 %). There was no difference in outcome comparing penetrating injury mechanisms to closed traction or blunt injuries, (p = 0.386, OR 1.75, 95 % CI 0.49-6.20). All patients with pan-plexal injuries had a poor outcome (15 of 33, 46 %). All patients who received intercostal (6 of 33, 18 %) or phrenic nerve transfers (3 of 33, 9 %) had a poor outcome.

Conclusion

Adult traumatic BPIs in this South African sample typically presented more than two months after injury and were comprised of a high proportion of penetrating injuries. Just under a third of surgically managed patients had a good outcome. Pan plexal injuries have uniformly poor outcomes. We recommend early referral for all TBPIs to a unit that manages BPI to improve outcomes.

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.

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.

Prospective study comparing outcomes of primary intraplexal repair versus distal nerve transfers in Narakas grade I birth brachial plexus palsy

To compare the results of intraplexal repair and distal nerve transfer in babies with birth brachial plexus palsy (BBPP), children with Narakas group I obstetric palsy were assigned to two groups of 16 each. Children in group A were treated with classical intraplexal repair and those in group B were treated by distal nerve transfers. At 6 months, all the children in group B had achieved Modified Medical Research Council (MMRC) grade 3 elbow flexion along with 8 of the 16 children in group A, which was a statistically significant difference. At 6 months, all the children in group B achieved MMRC grade 3 or higher shoulder abduction and 8 of the 16 children in group A had done so, which was also statistically significant. At the final follow-up, the distal transfer surgical treatment group had a significantly higher Mallet score. Distal nerve transfers have a significant advantage in early recovery in elbow flexion and shoulder abduction, but the outcomes became similar after 9 months.Level of evidence: III.

Hyperselective neurectomy in the treatment of elbow and wrist spasticity: an anatomical study and incision design

OBJECTIVE

Hyperselective neurectomy is used to treat spastic arm paralysis. The aim of the study was to analyze the nerve branching patterns of elbow and wrist flexors/pronator to inform hyperselective neurectomy approached.

METHODS

Eighteen upper extremities of fresh cadaver specimen were dissected. The number of motor branches from the musculocutaneous nerve to biceps brachii and brachialis, median nerve to pronator teres, flexor carpi radialis and ulnar nerve to flexor carpi ulnaris were counted. The origin site of each primary motor branch was documented.

RESULTS

Either biceps or brachialis was innervated by one or two primary motor branches. Pronator teres was innervated by one to three motor trunks and the pattern for flexor carpi radialis was a common trunk with other branches. The origin of the biceps and brachialis nerve trunk was located approximately 30% to 60% of the length of the arm. The median nerve branched to pronator teres and flexor carpi radialis at the region about 34mm (SD 18.8mm) above and 50mm (SD 14.9mm) below the medial epicondyle. Flexor carpi ulnaris was innervated by one to three motor trunks and the mean distance from the medial epicondyle to the origin of flexor carpi ulnaris nerve on ulnar nerve was 18.7 mm (SD 6.5mm).

CONCLUSION

Primary motor branches to elbow flexors, wrist flexors and pronators were various, while the regions of their origins were relatively settled. It was recommended the incisions be designed according to the location of the primary motor trunks.

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.

Management of C5 Palsy After Anterior Cervical Decompression Using Oberlin Nerve Transfer: A Case Report

C5 palsy is a potential complication of cervical decompression surgery from which many patients do not recover or partially recover function. We present the case of a 48-year-old patient who developed elbow flexion paralysis after anterior decompression surgery with fusion of the C5-C7 levels. Muscle function was not spontaneously restored until eight months after surgery. In this case, we performed an Oberlin procedure to restore the function of the arm. Muscle strength (5/5) and volume were obtained 13 months after surgery. A reasonable waiting period is required after C5 palsy in case spontaneous recovery occurs. Treatment decision should be based on the patient's symptoms. Nerve transfers have been shown to be effective when performed after six months, especially in Oberlin transfer.

Peripheral neural interfaces: Skeletal muscles are hyper-reinnervated according to the axonal capacity of the surgically rewired nerves

Advances in robotics have outpaced the capabilities of man-machine interfaces to decipher and transfer neural information to and from prosthetic devices. We emulated clinical scenarios where high- (facial) or low-neural capacity (ulnar) donor nerves were surgically rewired to the sternomastoid muscle, which is controlled by a very small number of motor axons. Using retrograde tracing and electrophysiological assessments, we observed a nearly 15-fold functional hyper-reinnervation of the muscle after high-capacity nerve transfer, demonstrating its capability of generating a multifold of neuromuscular junctions. Moreover, the surgically redirected axons influenced the muscle's physiological characteristics, by altering the expression of myosin heavy-chain types in alignment with the donor nerve. These findings highlight the remarkable capacity of skeletal muscles to act as biological amplifiers of neural information from the spinal cord for governing bionic prostheses, with the potential of expressing high-dimensional neural function for high-information transfer interfaces.

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.

Brief Electrical Stimulation Promotes Recovery after Surgical Repair of Injured Peripheral Nerves

Injured peripheral nerves regenerate their axons in contrast to those in the central nervous system. Yet, functional recovery after surgical repair is often disappointing. The basis for poor recovery is progressive deterioration with time and distance of the growth capacity of the neurons that lose their contact with targets (chronic axotomy) and the growth support of the chronically denervated Schwann cells (SC) in the distal nerve stumps. Nonetheless, chronically denervated atrophic muscle retains the capacity for reinnervation. Declining electrical activity of motoneurons accompanies the progressive fall in axotomized neuronal and denervated SC expression of regeneration-associated-genes and declining regenerative success. Reduced motoneuronal activity is due to the withdrawal of synaptic contacts from the soma. Exogenous neurotrophic factors that promote nerve regeneration can replace the endogenous factors whose expression declines with time. But the profuse axonal outgrowth they provoke and the difficulties in their delivery hinder their efficacy. Brief (1 h) low-frequency (20 Hz) electrical stimulation (ES) proximal to the injury site promotes the expression of endogenous growth factors and, in turn, dramatically accelerates axon outgrowth and target reinnervation. The latter ES effect has been demonstrated in both rats and humans. A conditioning ES of intact nerve days prior to nerve injury increases axonal outgrowth and regeneration rate. Thereby, this form of ES is amenable for nerve transfer surgeries and end-to-side neurorrhaphies. However, additional surgery for applying the required electrodes may be a hurdle. ES is applicable in all surgeries with excellent outcomes.

Nerve Transfer Surgery in Acute Flaccid Myelitis: Prognostic Factors, Long-Term Outcomes, Comparison With Natural History

BACKGROUND

Nerve transfer surgery is sometimes offered to patients with acute flaccid myelitis (AFM). The objectives of this study were to evaluate surgical efficacy, assess which clinical and neurophysiological data are valuable for preoperative planning, and report long-term outcomes.

METHODS

This is a single-center, retrospective case series of patients with AFM who received nerve transfer surgery. All patients had preoperative electromyography and nerve conduction studies (EMG/NCS). Matched control muscles that did not receive nerve transfer surgery were defined in the same cohort.

RESULTS

Ten patients meeting inclusion criteria received a total of 23 nerve transfers (19 upper extremity, four lower extremity). The mean age at symptom onset was 3.8 years, surgery was 0.5 to 1.25 years after diagnosis, and mean follow-up was 2.3 years (range 1.3 to 4.5 years). Among muscles with preoperative strength Medical Research Council (MRC) grade 0, muscles receiving nerve transfers performed significantly better than those that did not (MRC grade 2.17 ± 0.42 vs 0 ± 0, respectively, P = 0.0001). Preoperative EMG/NCS predicted worse outcomes in recipient muscles with more abundant acute denervation potentials (P = 0.0098). Donor nerves found to be partially denervated performed equally well as unaffected nerves. Limited data suggested functional improvement accompanying strength recovery.

CONCLUSIONS

Nerve transfer surgery is an effective strategy to restore strength for patients with AFM with persistent, severe motor deficits. Postoperative outcomes in patients with complete paralysis are better than the natural history of disease. This study demonstrates the utility of preoperative clinical and electrophysiological data in guiding patient selection for nerve transfer surgery.

Surgery for mononeuropathies

Advancement in microsurgical techniques and innovative approaches including greater use of nerve and tendon transfers have resulted in better peripheral nerve injury (PNI) surgical outcomes. Clinical evaluation of the patient and their injury factors along with a shift toward earlier time frame for intervention remain key. A better understanding of the pathophysiology and biology involved in PNI and specifically mononeuropathies along with advances in ultrasound and magnetic resonance imaging allow us, nowadays, to provide our patients with a logical and sophisticated approach. While functional outcomes are constantly being refined through different surgical techniques, basic scientific concepts are being advanced and translated to clinical practice on a continuous basis. Finally, a combination of nerve transfers and technological advances in nerve/brain and machine interfaces are expanding the scope of nerve surgery to help patients with amputations, spinal cord, and brain lesions.