Contralateral C7 nerve transfer with direct coaptation to restore lower trunk function after traumatic brachial plexus avulsion

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Femoral to sciatic nerve transfer: A cadaver study

Background

Proximal sciatic nerve injuries are a challenge to treat due to the limited options for donor nerves and the long distance needed for regeneration.

Methods

In our cadaveric study using five human cadavers, we aimed to evaluate the feasibility of transferring the tibial and common peroneal components of the sciatic nerve to the femoral nerve motor branches of the vastus medialis (VM) and vastus lateralis without the need for interposition nerve graft. The femoral nerve branches of the VM and lateralis were exposed anteriorly. The sciatic nerve was exposed posteriorly and passed through a narrow window within the adductor magnus and medial to the femur. The sciatic nerve was then separated into its tibial and peroneal components, which were then coapted to the VM and lateralis motor branches of the femoral nerve.

Results

Using the entire tibial and peroneal components of the sciatic nerve, we were able to gain more length and directly coapt the femoral nerve branches without utilizing interposition grafts. The disadvantage of this technique is suturing to a mixed nerve with motor and sensory components, which could compromise functional outcomes. Further studies are needed to determine how the procedure will impact a patient's gait cycle.

Conclusion

Clinical application is needed to determine preliminary outcomes before widespread utilization of this technique.

Evaluating the Ability of Brachial Plexus-Injured Patients to Control an Externally Powered (Myoelectric) Hand Prosthesis

BACKGROUND

Restoration of hand function after traumatic brachial plexus injury (BPI) remains a formidable challenge. Traditional methods such as nerve or free muscle transfers yield suboptimal results. Advancements in myoelectric prostheses, characterized by novel signal acquisition and improved material technology, show promise in restoring functional grasp. This study evaluated the ability of adults with a BPI injury to control an externally powered prosthetic hand using nonintuitive signals, simulating the restoration of grasp with a myoelectric prosthesis. It also assessed the effectiveness of a comprehensive multidisciplinary evaluation in guiding treatment decisions.

METHODS

A multidisciplinary brachial plexus team assessed adults with compromised hand function due to BPI. The feasibility of amputation coupled with fitting of a myoelectric prosthesis for grasp reconstruction was evaluated. Participants' ability to control a virtual or model prosthetic hand using surface electromyography (EMG) as well as with contralateral shoulder motion-activated linear transducer signals was tested. The patient's input and injury type, along with the information from the prosthetic evaluation, were used to determine the reconstructive plan. The study also reviewed the number of participants opting for amputation and a myoelectric prosthetic hand for grasp restoration, and a follow-up survey was conducted to assess the impact of the initial evaluation on decision-making.

RESULTS

Of 58 subjects evaluated, 47 (81%) had pan-plexus BPI and 42 (72%) received their initial assessment within 1 year post-injury. Forty-seven patients (81%) could control the virtual or model prosthetic hand using nonintuitive surface EMG signals, and all 58 could control it with contralateral uniscapular motion via a linear transducer and harness. Thirty patients (52%) chose and pursued amputation, and 20 (34%) actively used a myoelectric prosthesis for grasp. The initial evaluation was informative and beneficial for the majority of the patients, especially in demonstrating the functionality of the myoelectric prosthesis.

CONCLUSIONS

The study indicates that adults with traumatic BPI can effectively operate a virtual or model myoelectric prosthesis using nonintuitive control signals. The simulation and multidisciplinary evaluation influenced informed treatment choices, with a high percentage of patients continuing to use the myoelectric prostheses post-amputation, highlighting its long-term acceptance and viability.

LEVEL OF EVIDENCE

Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

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.

Retro Oesophageal Transfer of Contralateral C7 in Birth Brachial Plexus Injury - A Retrospective Study

Background: Presence of available healthy nerve roots on the injured side determines the outcome after nerve reconstruction. Paucity of nerve roots warrants contralateral C7 harvest for optimal results. We aim to study the risks and benefits of retro oesophageal transfer of contralateral C7 root in infants with birth brachial plexus injury. Methods: Study was carried out from 2017 to 2022 in 13 children who have undergone retro oesophageal transfer of contralateral C7 root to affected side. Follow-up period ranged from 8 to 60 months after the surgery. Motor power assessment was done using by active movement scale. Results: Average active movement score for abduction was found to be 6, elbow flexion 5.7, elbow extension 5.8, wrist extension 3, wrist flexion 4, finger flexion 4.8 and finger extension 3.8, respectively. No neurological deficits, limb length anomaly noted in the normal upper limb after contralateral C7 harvest. Conclusions: Retro oesophageal transfer of contralateral C7 is a safe technique in birth brachial plexus injury. The advantage of retro oesophageal transfer is reduction in the length of nerve grafts, thus helping in early neurotisation of distal forearm and hand muscles. The large axonal output from contralateral C7 can be used to reconstruct different nerves without any residual deficits on the normal side. Level of Evidence: Level IV (Therapeutic).

Surgical reconstructions for adult brachial plexus injuries. Part II: Treatments for total arm type

Brachial plexus injuries (BPI) contribute not only to physical dysfunction but also to socioeconomic aspects and psychological disability. Patients with total arm-type BPI will lose not only the shoulder and elbow function but also the hand function, making reconstruction particularly challenging. Reconstructive procedures commonly include nerve repair, grafting, neurotization (nerve transfer), tendon transfer and free functional muscle transfer (FFMT). Although it is difficult to achieve prehensile hand function, most of patients with total arm-type BPI can be treated with satisfied outcomes. In addition to surgical techniques, comprehensive rehabilitation is another important factor for successful outcomes, and efficient communication can help to boost patient morale and eliminate uncertainty.

[Contralateral C7 Nerve Transfer]

Complex brachial plexus injuries with multiple or complete root avulsions make intraplexic reconstruction impossible in some cases. Such cases necessitate the use of extraplexic nerve donors such as the spinal accessory nerve or intercostal nerves. The contralateral C7 root represents a donor with a high axon count and can be used as an axon source in such cases. We summarise current indications, surgical technique and functional results after a contralateral C7 transfer in cases of brachial plexus injury, describing some of our own cases and including a selective literature review.

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.

Prespinal Versus Conventional Hemicontralateral C7 Nerve Transfer in the Treatment of Total Brachial Plexus Roots Avulsion Injuries: A Retrospective Study With a Minimum Follow-Up Period of 4 Years

PURPOSE

Contralateral C7 (CC7)-to-median nerve transfer has been commonly used to restore hand function in brachial plexus injury. To shorten the nerve graft, the prespinal route was described and achieved direct coaptation when combined with humeral shortening osteotomy. The limb was positioned at 0° shoulder abduction and neutral head position. Given our concern about donor-site morbidity when harvesting the whole CC7 nerve and tension across the neurorrhaphy site after mobilization, we aimed to describe our modified prespinal route and compare its outcomes and complications with the conventional hemi-CC7 transfer.

METHODS

From 2004 to 2014, 39 patients with preganglionic total brachial plexus root avulsion injuries, with a minimum of 4 years of follow-up, were included. Overall, 20 and 19 patients underwent the conventional hemi-CC7-to-median nerve and hemi-CC7-to-lower trunk (LT) transfer through the modified prespinal route, respectively. The modified prespinal route was combined with bilateral clavicle shortening osteotomy to achieve direct coaptation to the LT at 45° shoulder abduction.

RESULTS

The modified prespinal route showed the median period to achieve ≥M3 hand grip assessed in clinical follow-up was shorter (26.5 months vs 45.5 months), and a higher proportion of patients achieved ≥M3 hand grip recovery (63% vs 30%). One patient experienced symptomatic phrenic nerve injury; however, the hemidiaphragm fully recovered after 6 months. The long-term donor-site complication rate was 2.6%, including one sensory abnormality, and no permanent donor-site weakness after hemi-CC7 harvesting was observed.

CONCLUSIONS

The modified prespinal route combined with clavicle osteotomy allowed direct coaptation to the LT and did not require head immobilization. It may allow a higher proportion of patients to achieve ≥M3 hand grip more quickly than conventional hemi-CC7 transfer.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Restoration of intrinsic hand function by superficial radial nerve: an anatomical study

BACKGROUND

The contralateral seventh cervical (cC7) nerve root transfer represents a cornerstone technique in treating total brachial plexus avulsion injury. Traditional cC7 procedures employ the entire ulnar nerve as a graft, which inevitably compromises its restorative capacity.

OBJECTIVE

Our cadaveric study seeks to assess this innovative approach aimed at preserving the motor branch of the ulnar nerve (MBUN). This new method aims to enable future repair stages, using the superficial radial nerve (SRN) as a bridge connecting cC7 and MBUN.

METHODS

We undertook a comprehensive dissection of ten adult cadavers, generously provided by the Department of Anatomy, Histology, and Embryology at Fudan University, China. It allowed us to evaluate the feasibility of our proposed technique. For this study, we harvested only the dorsal and superficial branches of the ulnar nerve, as well as the SRN, to establish connections between the cC7 nerve and recipient nerves (both the median nerve and MBUN). We meticulously dissected the SRN and the motor and sensory branches of the ulnar nerve. Measurements were made from the reverse point of the SRN to the wrist flexion crease and the coaptation point of the SRN and MBUN. Additionally, we traced the MBUN from distal to proximal ends, recording its maximum length. We also measured the diameters of the nerve branches and tallied the number of axons.

RESULTS

Our modified approach proved technically viable in all examined limbs. The distances from the reverse point of the SRN to the wrist flexion crease were 8.24 ± 1.80 cm and to the coaptation point were 6.60 ± 1.75 cm. The maximum length of the MBUN was 7.62 ± 1.03 cm. The average axon diameters in the MBUN and the anterior and posterior branches of the SRN were 1.88 ± 0.42 mm、1.56 ± 0.38 mm、2.02 ± 0.41 mm,respectively. The corresponding mean numbers of axons were 1426.60 ± 331.39 and 721.50 ± 138.22, and 741.90 ± 171.34, respectively.

CONCLUSION

The SRN demonstrated the potential to be transferred to the MBUN without necessitating a nerve graft. A potential advantage of this modification is preserving the MBUN's recovery potential.

Novel Approach of Femur Shortening With Insertion of Expandable Rod to Achieve End-to-End Repair of Sciatic Nerve Laceration

BACKGROUND

Sciatic nerve injuries are challenging for diagnosis and treatment. Particularly in proximally located high-grade injuries, neurorrhaphy often has poor outcomes. Most advocate autologous grafting and some more recently have suggested the value of knee flexion braces to facilitate end-to-end repair.

OBJECTIVE

To describe a case of femur shortening to facilitate tension-free, end-to-end sciatic nerve neurorrhaphy.

METHODS

The patient was a 17-year-old man who was injured by the propeller of a motor boat and suffered a series of lacerations to both lower extremities including transection of his right sciatic nerve in the proximal thigh. After extensive mobilization of the nerve, a greater than 7-cm gap was still present. The patient was treated with femur shortening to facilitate end-to-end coaptation. He subsequently had an expandable rod placed which was lengthened 1 mm per day until his leg length was symmetric.

RESULTS

Within 7 months postoperatively, the patient had an advancing Tinel sign and paresthesias to the dorsum of his foot. Nine months postoperatively, he had early mobility in his plantarflexion.

CONCLUSION

We present a novel method of femur shortening with insertion of an expandable rod to facilitate direct end-to-end and tension-free sciatic nerve neurorrhaphy in a proximally located injury. Furthermore, larger scale and comparative studies are warranted to further explore this and other techniques.

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.

Long-Term Outcome of 118 Acute Total Brachial Plexus Injury Patients Using Free Vascularized Ulnar Nerve Graft to Innervate the Median Nerve

BACKGROUND

 The restoration of finger movement in total brachial plexus injuries (BPIs) is an ultimate challenge. Pedicled vascularized ulnar nerve graft (VUNG) connecting a proximal root to distal target nerves has shown unpredictable outcomes. We modified this technique by harvesting VUNG as a free flap to reinnervate median nerve (MN). We analyzed the long-term outcomes of these methods.

METHODS

 From years 1998 to 2015, 118 acute total brachial plexus patients received free VUNG to innervate the MN. Patients were followed up at least 5 years after the initial surgery. Donor nerves included the ipsilateral C5 root (25 patients) or contralateral C7 root (CC7 = 93 patients). Recovery of finger and elbow flexion was evaluated with the modified Medical Research Council system. Michigan Hand Score and Quick-DASH were used to represent the patient-reported outcomes.

RESULTS

 For finger flexion, ipsilateral C5 transfer to MN alone yielded similar outcomes to MN + MCN (musculocutaneous nerve), while CC7 had significantly better finger flexion when coapted to MN alone than to MN + MCN. Approximately 75% patients were able to achieve finger flexion with nerve transfer alone. For elbow flexion, best outcome was seen in the ipsilateral C5 to MCN and MN.

CONCLUSION

 In acute total BPI, the priority is to identify the ipsilateral C5 root to innervate MN, with concomitant innervation of MCN to establish the best outcomes for finger and elbow flexion. CC7 is more reliable when used to innervate one target (MN).

LEVEL OF EVIDENCE

 III.

Restoration of Hand Function in Isolated Lower Brachial Plexus Injury with Brachioradialis to Flexor Pollicis Longus and Biceps to Flexor Digitorum Profundus Transfer

Background: Isolated lower (C8T1) brachial plexus injury (BPI) is uncommon and the aim of treatment is to achieve a satisfactory grasp enabling the use of the hand for daily activities. The aim of this study is to report the outcomes of the transfer of brachioradialis (BR) to flexor pollicis longus (FPL) and biceps to the flexor digitorum profundus (FDP) for an isolated lower BPI.

Methods: This is a retrospective study of all patients with an isolated lower BPI who underwent a BR to FPL and biceps to FDP transfer for restoration of digital flexion over a 1-year period from May 2019 to June 2020. Patient demographic and injury data were collected at the presentation. Outcomes data included the ability to grasp and perform activities of daily living and DASH score.

Results: The study included three patients (all men) with an average age of 30.3 years. All sustained an isolated lower BPI following a road traffic accident and tendon transfers were performed at a mean of 9.3 months after the initial injury. At a mean of 1-year follow-up, all three recovered grade M4 motor power of digital flexion, achieved good grasp function with pulp-to-palm distance of <1 cm. All are able to use the hand for independent as well as bimanual activities. The individual DASH scores were 36, 30 and 30.

Conclusions: BR to FPL for thumb flexion and biceps to FDP using fascia lata graft to restore finger flexion is simple and effective surgeries in patients with isolated lower BPI.

Level of Evidence: Level V (Therapeutic)

Reconstruction of hook grip function of the fingers in patients with traumatic brachial plexus injury

We described a reconstruction method for restoring hook grip function of the fingers in patients with total brachial plexus injury. The paralysed latissimus dorsi muscle was transferred to the upper limb as a pedicle flap and sutured to the flexor digitorum profundus tendons. The muscle was then reanimated with two intercostal donor nerves to the thoraco-dorsal nerve. Fourteen young adult patients (mean 23 years, range 17 to 32 years) with traumatic brachial plexus injury who underwent reconstruction using this technique from 2000 to 2019. After mean follow-up of 65 months (range 20 to 170), finger flexion of strength greater than or equal to M3 was achieved in 10 of the 14 patients. The mean weight that could be lifted using a hook grip was 2.6 kg, and that which could be lifted with both hands was 4.1 kg. The intercostal nerve-innervated latissimus dorsi muscle transfer can provide useful hook grip hand function without the need to sacrifice donor vessels or healthy muscles.Level of evidence: IV.

Improving Assessment of Disease Severity and Strategies for Monitoring Progression in Degenerative Cervical Myelopathy [AO Spine RECODE-DCM Research Priority Number 4]

STUDY DESIGN

Narrative Review.

OBJECTIVE

To (i) discuss why assessment and monitoring of disease progression is critical in Degenerative cervical myelopathy (DCM); (ii) outline the important features of an ideal assessment tool and (iii) discuss current and novel strategies for detecting subtle deterioration in DCM.

METHODS

Literature review.

RESULTS

Degenerative cervical myelopathy is an overarching term used to describe progressive injury to the cervical spinal cord by age-related changes of the spinal axis. Based on a study by Smith et al (2020), the prevalence of DCM is approximately 2.3% and is expected to rise as the global population ages. Given the global impact of this disease, it is essential to address important knowledge gaps and prioritize areas for future investigation. As part of the AO Spine RECODE-DCM (Research Objectives and Common Data Elements for Degenerative Cervical Myelopathy) project, a priority setting partnership was initiated to increase research efficiency by identifying the top ten research priorities for DCM. One of the top ten priorities for future DCM research was: What assessment tools can be used to evaluate functional impairment, disability and quality of life in people with DCM? What instruments, tools or methods can be used or developed to monitor people with DCM for disease progression or improvement either before or after surgical treatment?

CONCLUSIONS

With the increasing prevalence of DCM, effective surveillance of this population will require both the implementation of a monitoring framework as well as the development of new assessment tools.

Contralateral C7 nerve transfer in the treatment of upper-extremity paralysis: a review of anatomical basis, surgical approaches, and neurobiological mechanisms

The previous three decades have witnessed a prosperity of contralateral C7 nerve (CC7) transfer in the treatment of upper-extremity paralysis induced by both brachial plexus avulsion injury and central hemiplegia. From the initial subcutaneous route to the pre-spinal route and the newly-established post-spinal route, this surgical operation underwent a series of innovations and refinements, with the aim of shortening the regeneration distance and even achieving direct neurorrhaphy. Apart from surgical efforts for better peripheral nerve regeneration, brain involvement in functional improvements after CC7 transfer also stimulated scientific interest. This review summarizes recent advances of CC7 transfer in the treatment of upper-extremity paralysis of both peripheral and central causes, which covers the neuroanatomical basis, the evolution of surgical approach, and central mechanisms. In addition, motor cortex stimulation is discussed as a viable rehabilitation treatment in boosting functional recovery after CC7 transfer. This knowledge will be beneficial towards improving clinical effects of CC7 transfer.

Differences in management and treatment of traumatic adult pan brachial plexus injuries: a global perspective regarding continental variations

An expert opinion study was designed to query five countries and six brachial plexus surgeons regarding the demographics, mechanisms of injury, evaluation, timing of surgery, reconstructive strategies and controversies in adult traumatic pan brachial plexus injuries. Variations in assessing outcomes, management of neuropathic pain and future considerations were elucidated. Clear differences in regional demographics, mechanisms of injury, patient evaluation and treatment strategies were identified. The role of phrenic nerve and contralateral C7 transfer, acute use of free functioning muscle transfers, root reimplantation and amputation/myoelectric prosthetic fitting were regional/surgeon dependent. Comparison of outcomes across regions requires an understanding of the regional nuances of patient demographics, injury mechanisms, preferred reconstructive strategies and how outcomes are measured. Future studies are required to allow accurate regional comparisons.

Optimal Donor Nerve to Restore Elbow Flexion After Traumatic Brachial Plexus Injury: A Systematic Review and Meta-Analysis

BACKGROUND

Traumatic brachial plexus injuries (BPIs) often lead to devastating upper extremity deficits. Treatment frequently prioritizes restoring elbow flexion through transfer of various donor nerves; however, no consensus identifies optimal donor nerve sources.

OBJECTIVE

To complete a meta-analysis to assess donor nerves for restoring elbow flexion after partial and total BPI (TBPI).

METHODS

Original English language articles on nerve transfers to restore elbow flexion after BPI were included. Using a random-effects model, we calculated pooled, weighted effect size of the patients achieving a composite motor score of ≥M3, with subgroup analyses for patients achieving M4 strength and with TBPI. Meta-regression was performed to assess comparative efficacy of each donor nerve for these outcomes.

RESULTS

Comparison of the overall effect size of the 61 included articles demonstrated that intercostal nerves and phrenic nerves were statistically superior to contralateral C7 (cC7; P = .025, <.001, respectively) in achieving ≥M3 strength. After stratification by TBPI, the phrenic nerve was still superior to cC7 in achieving ≥M3 strength (P = .009). There were no statistical differences among ulnar, double fascicle, or medial pectoral nerves in achieving ≥M3 strength. Regarding M4 strength, the phrenic nerve was superior to cC7 (P = .01) in patients with TBPI and the ulnar nerve was superior to the medial pectoral nerve (P = .036) for partial BPI.

CONCLUSION

Neurotization of partial BPI or TBPI through the intercostal nerve or phrenic nerve may result in functional advantage over cC7. In patients with upper trunk injuries, neurotization using ulnar, median, or double fascicle nerve transfers has similarly excellent functional recovery.

Contralateral C7 Nerve Transfer for Stroke Recovery: New Frontier for Peripheral Nerve Surgery

Ischemic stroke remains a major cause of disability in the United States and worldwide. Following the large-scale implementation of stroke thrombectomy and the optimization of treatment protocols for acute stroke, the reduction in stroke-associated mortality has resulted in an increased proportion of stroke survivors, many of whom have moderate to severe disability. To date, the treatment of subacute and chronic stroke has remained a challenge. Several approaches, involving pharmacological interventions to promote neuroplasticity, brain stimulation strategies and rehabilitative interventions, are currently being explored at different stages of the translational spectrum, yet level 1 evidence is still limited. In a recent landmark study, surgical intervention using contralateral C7 nerve transfer, an approach used to treat brachial plexus injury, was implemented in patients with chronic stroke, demonstrating an added benefit to standard rehabilitation strategies, leading to improved motor performance and reduced spasticity. The procedure involved the transfer of the C7 nerve root and middle trunk from the uninjured extremity to the injured extremity using a short conduit that allows for faster regeneration and innervation of the injured upper extremity via the ipsilateral (contralesional) hemisphere. In this work, we review the rationale for using contralateral C7 nerve transfer in stroke, describe the surgical intervention with associated variations and limitations, and discuss the current evidence for the efficacy of this technique in ischemic stroke research.

Management of segmental bone defects of the upper limb: a scoping review with data synthesis to inform decision making

PURPOSE

Injuries to the long bones of the upper limb resulting in bone defects are rare but potentially devastating. Literature on the management of these injuries is limited to case reports and small case series. The aim of this study was to collate the most recent published work on the management of upper limb bone defects to assist with evidence based management when confronted with these cases.

METHODS

Following a preliminary search that confirmed the paucity of literature and lack of comparative trials, a scoping review using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for Scoping Reviews (PRISMA-ScR) was conducted. A literature search of major electronic databases was conducted to identify journal articles relating to the management of upper limb long bone defects published between 2010 and 2020.

RESULTS

A total of 46 publications reporting on the management of 341 patients were reviewed. Structural autograft, bone transport, one-bone forearm and the induced membrane technique were employed in an almost equal number of cases. The implemented strategies showed similar outcomes but different indications and complication profiles were observed.

CONCLUSION

Contemporary techniques for the management of post-traumatic upper limb bone defects all produce good results. Specific advantages, disadvantages and complications for each modality should be considered when deciding on which management strategy to employ for each specific patient, anatomical location, and defect size.

Direct Repair of the Lower Trunk to Residual Nerve Roots for Restoration of Finger Flexion After Total Brachial Plexus Injury

PURPOSE

Residual nerve root stumps have been used to neurotize the median nerve in an attempt to restore finger flexion function in patients suffering from total brachial plexus injury. However, the results have been unsatisfactory mainly because of the need to use a long nerve graft. The authors have tried to improve the quality of restored finger flexion by direct approximation of available (ruptured) ipsilateral root stumps to the lower trunk (LT). We sought to validate these results using objective outcome measures.

METHODS

This is a study of 27 cases of total posttraumatic brachial plexus palsies. In each case, the neck was explored and ruptured root stumps identified. The LT was mobilized by separating it from the posterior division and the medial cutaneous nerve of the forearm distally. The mobilized LT was then approximated directly to an ipsilateral root stump. The arm was immobilized against the trunk for 2 months. The patients were observed for return of function in the paralyzed upper limb. The presence and strength of finger flexion was measured using the British Medical Council grading.

RESULTS

The follow-up period was 36 to 74 months (average, 56.9 ± 13.7 months). Recovery of active finger flexion was M4 in 10 patients, M3 in 8 patients, and M2 to M0 in 9 patients. Meaningful recovery (M3 or greater) of finger flexion was achieved in 18 of 27 patients.

CONCLUSIONS

The results of active finger flexion can be improved by direct approximation of the LT to an ipsilateral root stump.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

[Research progress of peripheral nerve mismatch regeneration]

Objective

To review the research progress of peripheral nerve mismatch regeneration, and to provide reference for its related basic research and clinical treatment.

Methods

The pathophysiology of peripheral nerve after injury, several main factors affecting the mismatch regeneration of peripheral nerve, and the fate of axon after mismatch regeneration were summarized by referring to the relevant literature at home and abroad in recent years.

Results

Distal pathways and target organs can selectively affect the mismatch regeneration of peripheral nerves; different phenotypes of Schwann cells have different effects on the mismatch regeneration of peripheral nerves; studying the mechanism of action of exosomes from different Schwann cells on different types of axons can provide a new direction for solving the mismatch regeneration of peripheral nerves.

Conclusion

Peripheral nerve mismatch regeneration is affected by various factors. However, the specific mechanism and characteristics of these factors remain to be further studied.

"All in One or (W)hole in One Repair" for Adult Total Brachial Plexus Palsy

Background  Total brachial plexus palsy (TBPP) accounts for nearly 50% of all brachial plexus injuries. Since achieving a good functional hand was almost impossible, the aim was settled to get a good shoulder and elbow function. It was Gu, who popularized the concept of utilizing contralateral C7 (CC7) with vascularized ulnar nerve graft (VUNG) to get some hand function. We have modified it to suit our patients by conducting it as a single-stage procedure, thereby trying to get a functional upper limb. Methods  From 2009 to 2014, we had 20 TBPP patients. We feel nerve reconstruction is always better than any other salvage procedure, including free muscle transfer. We modified Gu's concept and present our concept of total nerve reconstruction as "ALL IN ONE OR (W)HOLE IN ONE REPAIR." Results  All patients able to move their reconstructed limbs independently or with the help of contralateral limbs. Three patients developed hook grip and one patient was able to incorporate limbs to do bimanual jobs. One important observation is that all the reconstructed limbs regain the bulk, and to a certain extent, the attitude and appearance looks normal, as patients no longer hide it or hang it in a sling. Conclusion  Adult brachial plexus injury itself is a devastating injury affecting young males. By doing this procedure, the affected limb is not dissociated from the rest of the body and rehabilitation can be aimed to get a supportive limb.

[Research progress of contralateral C 7 nerve root transfer via prevertebral pathway]

OBJECTIVE

To review the research progress on the establishment of prevertebral pathway in the treatment of unilateral total brachial plexus injury, cerebral palsy, stroke, and traumatic brain injury by contralateral C 7 nerve root transfer.

METHODS

The literature about contralateral C 7 nerve root transfer via prevertebral pathway at home and abroad was extensively reviewed, and the development, changes, advantages and disadvantages of various operation methods were analyzed and summarized.

RESULTS

After unilateral total brachial plexus injury, cerebral palsy, stroke, and traumatic brain injury, it can be repaired by a variety of surgical methods of the contralateral C 7 nerve root transfer via prevertebral pathway, which include the anterior subcutaneous tissue tunnel of the vertebral body, the passage under the sternocleidomastoid muscle, the posterior pharyngeal space and the anterior vertebral fascia passage, the modified posterior esophageal anterior vertebral passage, the anterior vertebral passage that cuts off the bilateral anterior scalene, and Huashan anterior pathway, etc. Among them, how to establish the shortest, safe, and effective way of anterior vertebral canal has been paid more attention and discussed by peripheral nerve repair doctors.

CONCLUSION

It is a safe and effective surgical method to repair unilateral total brachial plexus injury, cerebral palsy, stroke, and traumatic brain injury patients with contralateral C 7 nerve root transfer via prevertebral pathway.

Preliminary results of posterior contralateral cervical 7 nerve transposition in the treatment of upper limb plegia after a stroke

OBJECTIVE

This study aimed to explore a shorter and safer contralateral C7 transposition pathway for the treatment of central upper limb paralysis.

METHODS

From July 2018 to March 2019, 10 patients with central upper limb paralysis underwent posterior cervical 7 nerve transposition. The age of these patients ranged within 31-58 years old (average: 44 years old). These patients comprised of eight male patients and two female patients. Nine patients had cerebral hemorrhage, and one patient had a cerebral infarction. Furthermore, nine patients presented with spastic paralysis of the upper limbs and one patient presented with nonspastic paralysis. The duration of plegia before the operation ranged from 6 to 60 months (average: 26 months). The surgical procedure included transposition of the contralateral cervical 7 nerve root via a posterior vertebral approach under general anesthesia, and the distal part of the contralateral cervical 7 nerve was anastomosed with the proximal part of the ipsilateral cervical 7 nerve.

RESULTS

The length of the contralateral cervical 7 nerve was 5.16 ± 0.21 cm, which was directly anastomosed with the ipsilateral cervical 7 nerve. Neither case needed nerve transplantation. Most patients had temporary numbness in their healthy fingers, which all disappeared within three months. Up to now, the follow-up results are as follows: The spasticity of the affected upper limbs in five patients is lower than that before the operation, the pain and temperature sensation of the affected upper limbs in six patients are better than before the operation.

CONCLUSION

The distance of nerve transposition can be shortened by a posterior vertebral approach operation, where the contralateral C7 nerve can be anastomosed directly with the ipsilateral C7 nerve which may be effective for nerve regeneration and functional recovery. However, this conclusion still needs further research and verification.

Composite Grip Strength as a Marker of Outcome in Patients Surgically Treated for Degenerative Cervical Myelopathy

Study Design

Retrospective case series.

Purpose

This study aimed to examine the efficacy of composite grip strength as a marker of surgical outcome in patients with moderate to severe degenerative cervical myelopathy.

Overview of Literature

Degenerative cervical myelopathy causes loss of dexterity, muscle strength, and sensations in the hand. The impact of surgical management on improvement in composite grip strength has received scant attention.

Methods

This retrospective study was performed on degenerative cervical myelopathy patients with a complete composite grip strength assessment between January 2013 to January 2019. The Biometrics E-link hand kit was used for the assessment. The following parameters were measured: maximum grip strength, sustained grip strength, three-jaw pinch, maximum key pinch, and sustained key pinch. The pre- and postoperative functional status was assessed using the Nurick grade and the modified Japanese Orthopaedic Association (mJOA) score.

Results

A total of 40 patients were included in the study. The mean patient age was 51.9 years. The mean preoperative Nurick grade was 3.5 and the mJOA score was 10.9. The anterior approach was used in 25 patients, and the posterior approach was used in 15 patients. Four patients developed complications. Degenerative cervical myelopathy resulted in decreased handgrip and pinch strength as compared to normative Indian data. There was a significant improvement in the postoperative composite grip strength for all five parameters. There was no differential improvement between the anterior and posterior surgical groups. The improvement in the composite grip strength correlated with the improvement in functional scores.

Conclusions

Composite grip strength analysis is an objective method for assessing the impact of degenerative cervical myelopathy on grip strength and monitoring the postoperative improvement. Decompressive surgery resulted in global improvement in all the parameters of composite grip strength.

Contralateral C7 transfer to axillary and median nerves in rats with total brachial plexus avulsion

Background

Contralateral cervical 7 nerve (cC7) was used to repair two recipient nerves simultaneously for patients with total brachial plexus avulsion (TBPA).

Objective

To evaluate the effect of cC7 transfer to axillary and median nerves in rats with TBPA.

Methods

Eighty S-D rats were divided into 4 groups randomly on average. Group A: cC7-median nerve, Group B: cC7-axillary nerve, Group C: cC7-median and axillary nerves, Group D: TBPA without repair. The evaluation tools included behavioral tests, electromyogram (EMG), measurement of cross-sectional area of muscle fiber, nerve fiber count and gene expression assay.

Results

The effective rates of EMG were 90 and 70% in Flexor Carpi Radialis (FCR) in Group A and C, while 70 and 60% in deltoid (DEL) in Group B and C, respectively. In behavioral test, the differences of effective rates between groups were not significant. The mean cross-sectional area of FCR in Group A or C was significantly larger than that in Group D. Either the number of median or axillary nerve fibers in Group A, B or C was statistically more than that in Group D. No matter for FCR or DEL, there were no significant differences in the ratios of relative expression of Muscle Atrophy F-box(MAFBOX)and Muscle RING Finger 1(MURF1)among these groups.

Conclusion

Compared with cC7 transfer to median nerve, cC7 transfer to both median and axillary nerves did not affect median nerve recovery. The deltoid muscle also could be restored. The recovery proportion of axillary nerve was less than that of median nerve.

Adult Traumatic Brachial Plexus Injuries

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

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

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

Effects of humeral shortening on the three-dimensional configuration of the brachial plexus: a cadaveric study

This study reports the gains in length of nerves after three different humeral shortenings. Ten brachial plexuses were dissected. The lengths of the different parts of the brachial plexus were measured using a three-dimensional digitizing system after humeral shaft shortenings of 2, 4 and 6 cm and after a standardized force of 0.588 N was used to apply tension to the plexus. The feasibility of nerve suturing was studied. Humeral shortening allowed for significant gains in lengths of the musculocutaneous (42 mm), median (41 mm), ulnar (29 mm) and radial nerves (15 mm). A 2 cm humeral shortening allowed a 2 cm nerve gap to be directly sutured in 70% to 90% of cases. This study suggests that humeral shortening could allow direct suture of nerve defects, or shorten the length of nerve grafts required to bridge a gap.

Modified contralateral C7 nerve transfer: the possibility of permitting ulnar nerve recovery is confirmed by 10 cases of autopsy

Contralateral C7 nerve transfer surgery is one of the most important surgical techniques for treating total brachial plexus nerve injury. In the traditional contralateral C7 nerve transfer surgery, the whole ulnar nerve on the paralyzed side is harvested for transfer, which completely sacrifices its potential of recovery. In the present, novel study, we report on the anatomical feasibility of a modified contralateral C7 nerve transfer surgery. Ten fresh cadavers (4 males and 6 females) provided by the Department of Anatomy, Histology, and Embryology at the Medical College of Fudan University, China were used in modified contralateral C7 nerve transfer surgery. In this surgical model, only the dorsal and superficial branches of the ulnar nerve and the medial antebrachial cutaneous nerve on the paralyzed side (left) were harvested for grafting the contralateral (right) C7 nerve and the recipient nerves. Both the median nerve and deep branch of the ulnar nerve on the paralyzed (left) side were recipient nerves. To verify the feasibility of this surgery, the distances between each pair of coaptating nerve ends were measured by a vernier caliper. The results validated that starting point of the deep branch of ulnar nerve and the starting point of the medial antebrachial cutaneous nerve at the elbow were close to each other and could be readily anastomosed. We investigated whether the fiber number of donor and recipient nerves matched one another. The axons were counted in sections of nerve segments distal and proximal to the coaptation sites after silver impregnation. Averaged axon number of the ulnar nerve at the upper arm level was approximately equal to the sum of the median nerve and proximal end of medial antebrachial cutaneous nerve (left: 0.94:1; right: 0.93:1). In conclusion, the contralateral C7 nerve could be transferred to the median nerve but also to the deep branch of the ulnar nerve via grafts of the ulnar nerve without deep branch and the medial antebrachial cutaneous nerve. The advantage over traditional surgery was that the recovery potential of the deep branch of ulnar nerve was preserved. The study was approved by the Ethics Committee of Fudan University (approval number: 2015-064) in July, 2015.

Surgery for nerve injury: current and future perspectives

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

Treatment of Central Paralysis of Upper Extremity Using Contralateral C7 Nerve Transfer via Posterior Spinal Route

BACKGROUND

Contralateral C7 nerve transfer is widely applied for the treatment of brachial plexus injuries or central paralysis of the upper extremities. The surgical approach has evolved from the precervical subcutaneous route to the prespinal route, which is currently the most commonly used one. We report a patient with central paralysis of the right upper extremity treated with contralateral C7 nerve transfer via the posterior spinal route.

CASE DESCRIPTION

A 59-year-old female patient was admitted on 3 July, 2018 with right hemiplegia. The muscle strength of the right lower and upper extremities was grade 4 and 0, respectively. On the basis of magnetic resonance imaging, she was diagnosed with central paralysis of the right upper extremity. Considering the short length of the patient's healthy C7 nerve, contralateral C7 nerve transfer via the posterior spinal route was performed. No intraoperative complication was encountered. The patient reported slight numbness of the volar side of the left thumb, middle finger, and index finger after surgery. The patient showed a right shrug movement 1.5 months after surgery.

CONCLUSION

We propose carrying out contralateral C7 nerve transfer via the posterior spinal route because of the shorter distance, no need for nerve transplantation, and low occurrence of the complications encountered with the prespinal route (such as vertebral artery injuries, esophageal fistula, and upper extremity pain when swallowing).

Contralateral C7 transfer to lower trunk via a subcutaneous tunnel across the anterior surface of the chest and neck for total brachial plexus root avulsion: a cadaveric study

BACKGROUND

Restoration of hand function after total brachial plexus root avulsion (tBPRA) is a difficult problem in surgical management. A new modified approach in repairing tBPRA is to use a subcutaneous tunnel across the anterior surface of the chest and neck, and then transfer the contralateral C7 root (cC7) to the lower trunk. However, the anatomical details of this method have not yet been fully described and assessed. The objective of this study was to quantitatively describe the nerve transfer using a cadaveric surgical simulation.

MATERIALS AND METHODS

Brachial plexuses were dissected from 12 adult cadavers, producing 24 sides of brachial plexuses for nerve transfer experiments. We performed simulated cC7 transfers to the lower trunk via a subcutaneous tunnel across the anterior surface of the chest and neck. Measurements of the nerves were made and transfers quantitatively documented.

RESULTS

With the affected shoulder and arm in a neutral position, cC7 and C8-T1 could be sutured directly together in 75% of the cadavers. A nerve graft length of 4.6 ± 1.18 cm was needed to bridge the gap in the remaining cadavers. For cadavers where distal cC7 was directly connected with the lower trunk, 54.17% could be sutured, and an average nerve graft length of 3.9 cm was needed in the remains.

CONCLUSIONS

For surgical management of total tBPRA, transfer of the cC7 nerve to the C8-T1 or lower trunk via a subcutaneous tunnel across the chest and neck will likely be superior to a conventional cC7 root transfer in the clinic. This approach shortens the nerve graft needed and nerve regeneration distance, decreases the number of neurorrhaphy sites, and makes full use of the donor nerves, which may benefit hand flexion restoration.

Outcome of contralateral C7 transfers to different recipient nerves after global brachial plexus avulsion

INTRODUCTION

Contralateral cervical seventh nerve root (CC7) transfer has been widely applied for treatment of traumatic brachial plexus injury. The purpose of the study was to evaluate outcomes of patients with global brachial plexus avulsion (GBPA) after CC7 transfer and compare the recoveries of median nerve as the only recipient nerve and one of the multiple recipient nerves.

METHODS

A retrospective review of 51 patients treated with CC7 transfers after GBPA was carried out. The British Medical Research Council (MRC) grading system and range of joint motion (ROM) were used for motor and sensory assessment.

RESULTS

The effective rates of FCR were 57.7%, 45.5%, and 36.4% in CC7 transfer to median nerve (CC7-Md), CC7 transfer to median nerve and biceps branch (CC7-Md+Bic) and CC7 transfer to median nerve and triceps branch (CC7-Md+Tric) groups, respectively. There were no statistical differences no matter in FCR or FDS among groups. The effective rate in biceps had no significant difference with that in triceps. The effective sensory recovery rate was 65.4%, 54.5%, and 36.4% in CC7-Md, CC7-Md+Bic, and CC7-Md+Tric groups. There were no statistical differences in the sensory effective recovery rate among groups. All the ROMs were improved significantly after surgery. The improvement of ROM of elbow flexion after surgery in CC7-Md+Bic group was significantly larger than that of elbow extension after surgery in CC7-Md+Tric group (p = 0.047).

CONCLUSIONS

The CC7 transfer contributed to the functional improvement of the hand and wrist for the patients with global brachial plexus avulsion. The whole CC7 could be used to repair more than one recipient nerve (including median nerve) without affecting the recovery of median nerve. When CC7 was used to repair two nerves, biceps branch might be preferred to choose as one recipient nerve rather than triceps branch.

Contralateral C7 to C7 nerve root transfer in reconstruction for treatment of total brachial plexus palsy: anatomical basis and preliminary clinical results

OBJECTIVEContralateral C7 (CC7) nerve root has been used as a donor nerve for targeted neurotization in the treatment of total brachial plexus palsy (TBPP). The authors aimed to study the contribution of C7 to the innervation of specific upper-limb muscles and to explore the utility of C7 nerve root as a recipient nerve in the management of TBPP.METHODSThis was a 2-part investigation. 1) Anatomical study: the C7 nerve root was dissected and its individual branches were traced to the muscles in 5 embalmed adult cadavers bilaterally. 2) Clinical series: 6 patients with TBPP underwent CC7 nerve transfer to the middle trunk of the injured side. Outcomes were evaluated with the modified Medical Research Council scale and electromyography studies.RESULTSIn the anatomical study there were consistent and predominantly C7-derived nerve fibers in the lateral pectoral, thoracodorsal, and radial nerves. There was a minor contribution from C7 to the long thoracic nerve. The average distance from the C7 nerve root to the lateral pectoral nerve entry point of the pectoralis major was the shortest, at 10.3 ± 1.4 cm. In the clinical series the patients had been followed for a mean time of 30.8 ± 5.3 months postoperatively. At the latest follow-up, 5 of 6 patients regained M3 or higher power for shoulder adduction and elbow extension. Two patients regained M3 wrist extension. All regained some wrist and finger extension, but muscle strength was poor. Compound muscle action potentials were recorded from the pectoralis major at a mean follow-up of 6.7 ± 0.8 months; from the latissimus dorsi at 9.3 ± 1.4 months; from the triceps at 11.5 ± 1.4 months; from the wrist extensors at 17.2 ± 1.5 months; from the flexor carpi radialis at 17.0 ± 1.1 months; and from the digital extensors at 22.8 ± 2.0 months. The average sensory recovery of the index finger was S2. Transient paresthesia in the hand on the donor side, which resolved within 6 months postoperatively, was reported by all patients.CONCLUSIONSThe C7 nerve root contributes consistently to the lateral pectoral nerve, the thoracodorsal nerve, and long head of the triceps branch of the radial nerve. CC7 to C7 nerve transfer is a reconstructive option in the overall management plan for TBPP. It was safe and effective in restoring shoulder adduction and elbow extension in this patient series. However, recoveries of wrist and finger extensions are poor.

Contralateral medial pectoral nerve transfer with free gracilis muscle transfer in old brachial plexus palsy

BACKGROUND

There is a very small chance of success for nerve reconstruction in patients with old total brachial plexus palsy who visit after 2 y or suffer from flail upper extremity after the failure of previous operations.

MATERIALS AND METHODS

For these individuals, the surgeon has to find a recipient motor nerve to perform free gracilis muscle transplantation. In this study, contralateral medial pectoral nerve from the intact side was transferred to the damaged side as a recipient nerve. Then, in the second operation, approximately 15 mo later, the free gracilis muscle transfer was performed. The gracilis muscle was removed and transferred to provide elbow and finger flexion.

RESULTS

In a retrospective study (over 10 y), we reviewed 68 patients for whom this method had been performed. After 1 y, the results were investigated using the Medical Research Council grading system. Five patients did not participate in the study, and the muscle underwent necrosis in two patients. M3 and M4 muscle power was regained in 26 (42.6%) and 21 (34.4%) patients, respectively.

CONCLUSIONS

Contralateral pectoral nerve transfer followed by free muscle transplantation can be a good option for patients with old total brachial plexus palsy.

[Construction of Chinese peripheral nerve society and progress in repair and reconstruction of peripheral nerve injury]

The peripheral nerve group of the reparative and reconstructive surgery committee (branch of Chinese association of rehabilitation medicine) was established in 1995. Major research progress has been made in the repair, regeneration, and reconstruction of peripheral nerve injury. Professor GU Yudong initiated the contralateral cervical7 root (CC7) transfer for the treatment of total brachial plexus root injury in 1986. Now this method has been applied safely and effectively for 30 years with profound progress and refinement. In addition, the repair and reconstruction of peripheral nerve injury had achieved great development such as the treatment of spastic paralysis of upper limb, CC7 transfer using a modified prespinal route, the reconstruction of bladder function after spinal cord injury, the development of acellular allograft nerve, the small gap suture technique, the functioning free gracilis muscle transplantation, and contralateral S ₁ transfer which have been widely used in clinical application with good outcomes. With the progress of the biological manufacturing of peripheral nerve bio-materials and the remodeling of central nervous system after brachial plexus injury, a novel peripheral neuroscience research field was growing up. It is still a challenge for surgeons and scholars in this field to insist on the popularization and improvement of peripheral nerve repair and reconstruction by microsurgical technique, and to make efforts to transform the results of peripheral nerve research into clinical practice.

Restoration of active pick-up function in patients with total brachial plexus avulsion injuries

We designed multiple nerve transfers in one surgery to restore active pick-up function in patients with total brachial plexus avulsion injuries. Forty patients with total brachial plexus avulsion injuries first underwent multiple nerve transfers. These included transfer of the accessory nerve onto the suprascapular nerve to recover shoulder abduction, contralateral C7 nerve onto the lower trunk via the modified prespinal route with direct coaptation to restore lower trunk function and onto the musculocutaneous nerve with interpositional bridging by medial antebrachial cutaneous nerve arising from lower trunk to restore elbow flexion, and the phrenic nerve onto the posterior division of lower trunk to recover elbow and finger extension. At least three years after surgery, the patients who had a meaningful recovery were selected to perform secondary reconstruction to restore active pick-up function. Active pick-up function was successfully restored in ten patients after they underwent multiple nerve transfers combined with additional secondary functional hand reconstructions.

LEVEL OF EVIDENCE

IV.

Total brachial plexus injury: contralateral C7 root transfer to the lower trunk versus the median nerve

Contralateral C7 (cC7) root transfer to the healthy side is the main method for the treatment of brachial plexus root injury. A relatively new modification of this method involves cC7 root transfer to the lower trunk via the prespinal route. In the current study, we examined the effectiveness of this method using electrophysiological and histological analyses. To this end, we used a rat model of total brachial plexus injury, and cC7 root transfer was performed to either the lower trunk via the prespinal route or the median nerve via a subcutaneous tunnel to repair the injury. At 4, 8 and 12 weeks, the grasping test was used to measure the changes in grasp strength of the injured forepaw. Electrophysiological changes were examined in the flexor digitorum superficialis muscle. The change in the wet weight of the forearm flexor was also measured. Atrophy of the flexor digitorum superficialis muscle was assessed by hematoxylin-eosin staining. Toluidine blue staining was used to count the number of myelinated nerve fibers in the injured nerves. Compared with the traditional method, cC7 root transfer to the lower trunk via the prespinal route increased grasp strength of the injured forepaw, increased the compound muscle action potential maximum amplitude, shortened latency, substantially restored tetanic contraction of the forearm flexor muscles, increased the wet weight of the muscle, reduced atrophy of the flexor digitorum superficialis muscle, and increased the number of myelinated nerve fibers. These findings demonstrate that for finger flexion functional recovery in rats with total brachial plexus injury, transfer of the cC7 root to the lower trunk via the prespinal route is more effective than transfer to the median nerve via subcutaneous tunnel.

Is it necessary to use the entire root as a donor when transferring contralateral C7 nerve to repair median nerve?

If a partial contralateral C₇ nerve is transferred to a recipient injured nerve, results are not satisfactory. However, if an entire contralateral C₇ nerve is used to repair two nerves, both recipient nerves show good recovery. These findings seem contradictory, as the above two methods use the same donor nerve, only the cutting method of the contralateral C₇ nerve is different. To verify whether this can actually result in different repair effects, we divided rats with right total brachial plexus injury into three groups. In the entire root group, the entire contralateral C₇ root was transected and transferred to the median nerve of the affected limb. In the posterior division group, only the posterior division of the contralateral C₇ root was transected and transferred to the median nerve. In the entire root + posterior division group, the entire contralateral C₇ root was transected but only the posterior division was transferred to the median nerve. After neurectomy, the median nerve was repaired on the affected side in the three groups. At 8, 12, and 16 weeks postoperatively, electrophysiological examination showed that maximum amplitude, latency, muscle tetanic contraction force, and muscle fiber cross-sectional area of the flexor digitorum superficialis muscle were significantly better in the entire root and entire root + posterior division groups than in the posterior division group. No significant difference was found between the entire root and entire root + posterior division groups. Counts of myelinated axons in the median nerve were greater in the entire root group than in the entire root + posterior division group, which were greater than the posterior division group. We conclude that for the same recipient nerve, harvesting of the entire contralateral C₇ root achieved significantly better recovery than partial harvesting, even if only part of the entire root was used for transfer. This result indicates that the entire root should be used as a donor when transferring contralateral C₇ nerve.

Evaluation of nerve transfer options for treating total brachial plexus avulsion injury: A retrospective study of 73 participants

Despite recent great progress in diagnosis and microsurgical repair, the prognosis in total brachial plexus-avulsion injury remains unfavorable. Insufficient number of donors and unreasonable use of donor nerves might be key factors. To identify an optimal treatment strategy for this condition, we conducted a retrospective review. Seventy-three patients with total brachial plexus avulsion injury were followed up for an average of 7.3 years. Our analysis demonstrated no significant difference in elbow-flexion recovery between phrenic nerve-transfer (25 cases), phrenic nerve-graft (19 cases), intercostal nerve (17 cases), or contralateral C₇-transfer (12 cases) groups. Restoration of shoulder function was attempted through anterior accessory nerve (27 cases), posterior accessory nerve (10 cases), intercostal nerve (5 cases), or accessory + intercostal nerve transfer (31 cases). Accessory nerve + intercostal nerve transfer was the most effective method. A significantly greater amount of elbow extension was observed in patients with intercostal nerve transfer (25 cases) than in those with contralateral C₇ transfer (10 cases). Recovery of median nerve function was noticeably better for those who received entire contralateral C₇ transfer (33 cases) than for those who received partial contralateral C₇ transfer (40 cases). Wrist and finger extension were reconstructed by intercostal nerve transfer (31 cases). Overall, the recommended surgical treatment for total brachial plexus-avulsion injury is phrenic nerve transfer for elbow flexion, accessory nerve + intercostal nerve transfer for shoulder function, intercostal nerves transfer for elbow extension, entire contralateral C₇ transfer for median nerve function, and intercostal nerve transfer for finger extension. The trial was registered at ClinicalTrials.gov (identifier: NCT03166033).

Outcome of Finger Extension After Nerve Transfer to Repair C7-T1 Brachial Plexus Palsy in Rats: Comparative Study of the Supinator Motor Branch Transfer to the Posterior Interosseous Nerve and the Contralateral C7 Transfer to the Lower Trunk

BACKGROUND

Functional recovery following supinator motor branch transfer requires further investigation.

OBJECTIVE

To compare the outcome of finger extension after supinator motor branch transfer or contralateral C7 (cC7) transfer in C7-T1 brachial plexus palsies in rats.

METHODS

In this study, 120 adult rats underwent C7-T1 nerve root avulsion and received different nerve transfer repairs: group A, cC7 nerve transfer to the lower trunk; group B, supinator motor branch nerve transfer to the posterior interosseous nerve (PIN); and group C, no repair. The ethology of the rats, latency and amplitude of the compound muscle action potential from the PIN, muscle mass and muscle fiber cross-sectional area of the extensor digitorum communis and extensor carpi ulnaris, and number of myelinated nerve fibers in the PIN were examined postoperatively.

RESULTS

There was no finger extension in group C. We observed finger extension in groups A and B 50.2 ± 5.66 and 13.1 ± 2.08 days postoperatively, respectively. Finger extension restoration in group B was greater than that in group A at 4, 8, and 12 weeks postoperatively ( P < .05). Sixteen weeks after surgery, the recovery rate of the myelinated nerve fibers in group A was marginally higher than that in group B, but the difference was not significant. Of the other measured values, group B showed a greater and significant improvement compared to group A ( P < .05).

CONCLUSION

Supinator motor branch transfer allows for faster recovery and is a more effective procedure for restoring finger extension in C7-T1 brachial plexus palsies.

Supination Contractures in Brachial Plexus Birth Palsy: Long-Term Upper Limb Function and Recurrence After Forearm Osteotomy or Nonsurgical Treatment

PURPOSE

Forearm osteotomy for supination deformity in brachial plexus birth palsy (BPBP) may lead to improved function of the upper limb. However, recurrence rates are high and limit satisfactory results.

METHODS

We reviewed the long-term outcome of the entire upper limb of 22 BPBP patients with a supination contracture who were treated by forearm osteotomy and compared them with an age-matched group that was treated nonsurgically (n = 28). Recurrence was defined as a passive pronation below 30°.

RESULTS

The median follow-up was 5.0 years (range, 1.5-14 years). The mean passive pronation after forearm osteotomy, including patients with recurrence at follow-up, improved from -1° (SD, 9°) to 33° (SD, 48°) at final follow-up, mean active wrist extension improved from 23° (SD, 40°) to 41° (SD, 38°). An overall improvement of wrist and hand strength was present. In patients without recurrence, pronation improved to a mean of 66° (SD, 23°) at final follow-up. Recurrence of the supination contracture was present in 9 cases (41%) and was only present in patients with a single bone osteotomy. Recurrence was associated with lower age at surgery (recurrence mean, 4 [SD, 1.2] and no recurrence 8 [SD 4.5]), lower shoulder external rotation (recurrence mean, 28 [SD, 17] and no recurrence 49 [SD, 23]), and overall lower hand function at baseline.

CONCLUSIONS

Forearm osteotomy improves forearm pronation and hand function. Recurrence should be considered as a potential complication after forearm osteotomy and is associated with young age and lower function of shoulder and hand. Single-bone osteotomy might also be a risk factor for recurrence.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

A systematic review of outcomes of contralateral C-7 transfer for the treatment of traumatic brachial plexus injury: an international comparison

OBJECTIVE

The effectiveness of contralateral C-7 (CC7) transfer is controversial, yet this procedure has been performed around the world to treat brachial plexus injuries. The authors performed a systematic review to study whether Asian countries reported better outcomes after CC7 transfer compared with “other” countries.

METHODS

A systematic literature search using PubMed, EMBASE, and 3 Chinese databases was completed. Patient outcomes of CC7 transfer to the median and musculocutaneous (MC) nerves were collected and categorized into 2 groups: Asia and “other” countries. China was included as a subcategory of Asia because investigators in China published the majority of the collected studies. To compare outcomes among studies, we created a normalized Medical Research Council (MRC) scale.

RESULTS

For median nerve outcomes, Asia reported that 41% of patients achieved an MRC grade of ≥ M3 of wrist flexion compared with 62% in “other” countries. For finger flexion, Asia found that 41% of patients reached an MRC grade of ≥ M3 compared with 38% in “other” countries. Asia reported that 60% of patients achieved ≥ S3 sensory recovery, compared with 32% in “other” countries. For MC nerve outcomes, 75% of patients from both Asia and “other” countries reached M4 and M3 in elbow flexion.

CONCLUSIONS

Current data did not demonstrate that studies from Asian countries reported better outcomes of CC7 transfer to the median and MC nerves. Future studies should focus on comparing outcomes of different surgical strategies for CC7 transfer.

Functional connectivity of motor cortical network in patients with brachial plexus avulsion injury after contralateral cervical nerve transfer: a resting-state fMRI study

Introduction

The purpose of this study is to assess the functional connectivity of the motor cortical network in patients with brachial plexus avulsion injury (BPAI) after contralateral C7 nerve transfer, using resting-state functional magnetic resonance imaging (RS-fMRI).

Methods

Twelve patients with total brachial plexus root avulsion underwent RS-fMRI after contralateral C7 nerve transfer. Seventeen healthy volunteers were also included in this fMRI study as controls. The hand motor seed regions were defined as region of interests in the bilateral hemispheres. The seed-based functional connectivity was calculated in all the subjects. Differences in functional connectivity of the motor cortical network between patients and healthy controls were compared.

Results

The inter-hemispheric functional connectivity of the M1 areas was increased in patients with BPAI compared with the controls. The inter-hemispheric functional connectivity between the supplementary motor areas was reduced bilaterally.

Conclusions

The resting-state inter-hemispheric functional connectivity of the bilateral M1 areas is altered in patients after contralateral C7 nerve transfer, suggesting a functional reorganization of cerebral cortex.

Electronic supplementary material

The online version of this article (doi:10.1007/s00234-017-1796-0) contains supplementary material, which is available to authorized users.