Nerve transfers for severe brachial plexus injuries: a review

Functional motor recovery from motoneuron axotomy is compromised in mice with defective corticospinal projections

Brachial plexus injury (BPI) and experimental spinal root avulsion result in loss of motor function in the affected segments. After root avulsion, significant motoneuron function is restored by re-implantation of the avulsed root. How much this functional recovery depends on corticospinal inputs is not known. Here, we studied that question using Celsr3|Emx1 mice, in which the corticospinal tract (CST) is genetically absent. In adult mice, we tore off right C5-C7 motor and sensory roots and re-implanted the right C6 roots. Behavioral studies showed impaired recovery of elbow flexion in Celsr3|Emx1 mice compared to controls. Five months after surgery, a reduced number of small axons, and higher G-ratio of inner to outer diameter of myelin sheaths were observed in mutant versus control mice. At early stages post-surgery, mutant mice displayed lower expression of GAP-43 in spinal cord and of myelin basic protein (MBP) in peripheral nerves than control animals. After five months, mutant animals had atrophy of the right biceps brachii, with less newly formed neuromuscular junctions (NMJs) and reduced peak-to-peak amplitudes in electromyogram (EMG), than controls. However, quite unexpectedly, a higher motoneuron survival rate was found in mutant than in control mice. Thus, following root avulsion/re-implantation, the absence of the CST is probably an important reason to hamper axonal regeneration and remyelination, as well as target re-innervation and formation of new NMJ, resulting in lower functional recovery, while fostering motoneuron survival. These results indicate that manipulation of corticospinal transmission may help improve functional recovery following BPI.

Injuries associated with serious brachial plexus involvement in polytrauma among patients requiring surgical repair

BACKGROUND

Brachial plexus injury occurs in up to 5% of polytrauma cases involving motorcycle crashes and in approximately 4% of severe winter sports injuries. One of the conditions for the success of operative therapy is early detection, ideally within three months of injury. The aim of this study was to evaluate associated injuries in patients with severe brachial plexus injury and determine whether there is a characteristic concomitant injury (or injuries), the presence of which, in the polytrauma, could act as a marker for nerve structures involvement and whether there are differences in severity of polytrauma accompanying specific types of brachial plexus injury.

METHODS

We evaluated retrospectively 84 surgical patients from our department, from 2008 to 2011, that had undergone brachial plexus reconstruction. For all, an injury severity scale (ISS) score and all major associated injuries were determined.

RESULTS

72% of patients had an upper, 26% had a complete and only 2% had a lower brachial plexus palsy. The main cause was motorcycle crashes (60%) followed by car crashes (15%). The average ISS was 35.2 (SD=23.3), although, values were significantly higher in cases involving a coma (59.3, SD=11.0). The lower and complete plexus injuries were significantly associated with coma and fractures of the shoulder girdle and injuries of lower limbs, thoracic organs and head. Upper plexus injuries were associated with somewhat less severe injuries of the upper and lower extremities and less severe injuries of the spine.

CONCLUSION

Serious brachial plexus injury is usually accompanied by other severe injuries. It occurs in high-energy trauma and it can be stated that patients involved in motorcycle and car crashes with multiple fractures of the shoulder girdle are at high risk of nerve trauma. This is especially true for patients in a primary coma. Lower and complete brachial plexus injuries are associated with higher injury severity scale.

End-to-side neurorrhaphy in brachial plexus reconstruction

Object

Although a number of theoretical and experimental studies dealing with end-to-side neurorrhaphy (ETSN) have been published to date, there is still a considerable lack of clinical trials investigating this technique. Here, the authors describe their experience with ETSN in axillary and musculocutaneous nerve reconstruction in patients with brachial plexus palsy.

Methods

From 1999 to 2007, out of 791 reconstructed nerves in 441 patients treated for brachial plexus injury, the authors performed 21 axillary and 2 musculocutaneous nerve sutures onto the median, ulnar, or radial nerves. This technique was only performed in patients whose donor nerves, such as the thoracodorsal and medial pectoral nerves, which the authors generally use for repair of axillary and musculocutaneous nerves, respectively, were not available. In all patients, a perineurial suture was carried out after the creation of a perineurial window.

Results

The overall success rate of the ETSN was 43.5%. Reinnervation of the deltoid muscle with axillary nerve suture was successful in 47.6% of the patients, but reinnervation of the biceps muscle was unsuccessful in the 2 patients undergoing musculocutaneous nerve repair.

Conclusions

The authors conclude that ETSN should be performed in axillary nerve reconstruction but only when commonly used donor nerves are not available.

Outcome of contralateral C7 transfer to two recipient nerves in 22 patients with the total brachial plexus avulsion injury

The treatment of total brachial plexus avulsion injury is difficult with unfavorable prognosis. This report presents our experience on the contralateral C7 (CC7) nerve root transfer to neurotize two recipient nerves in the patients with total BPAI. Twenty-two patients underwent CC7 transfer to two target nerves in the injured upper limb. The patients' ages ranged from 13 to 48 years. The entire CC7 was transferred to pedicled ulnar nerve in the first stage. The interval between trauma and surgery ranged from 1 to 13 months. The ulnar nerve was transferred to recipients (median nerve and biceps branch or median nerve and triceps branch) at 2-13 months after first operation. The motor recovery of wrist and finger flexor to M3 or greater was achieved in 68.2% of patients, the sensory recovery of median nerve area recovered to S3 or greater in 45.5% of patients. The functional recovery of elbow flexor to M3 or greater was achieved in 66.7% of patients with repair of biceps branch and 20% of patients with repair of the triceps branch (P < 0.05). There were no statistical differences in median nerve function recovery at comparisons of the age younger and older than 20-years-old and the intervals between trauma and surgery. In conclusion, the use of CC7 transfer for repair two recipient nerves might be an option for treatment of total BPAI. The functional recovery of the repaired biceps branch appeared to be better than that of the triceps branch.

Reconstruction of shoulder abduction by multiple nerve fascicle transfer through posterior approach

PURPOSE

To evaluate the feasibility and clinical efficacy of multiple nerve fascicle transfer through posterior approach for reconstruction of shoulder abduction in patients with C5 or upper brachial plexus injury.

METHODS

11 patients (aged between 17 and 56 years) with dysfunction of shoulder abduction post C5 or upper brachial plexus injury were recruited in this study. Among them, four out of 11 patients also had dysfunction of elbow flexion simultaneously. The duration from injury to the surgery ranged from 4 to 12 months, with an average of 6.7 months. The affected shoulder joints showed abduction, extension and elevation dysfunction, but the muscle strength of shoulder shrugging and elbow extension was graded to M4 or higher. Accessory nerve was transferred to the suprascapular nerve and triceps muscle was branched to the axillary nerve through posterior approach. Ulnar fascicle was transferred to the motor branches of biceps for the 4 patients involved with elbow flexion dysfunction.

RESULTS

Ten out of 11 cases were followed-up for 15-36 months. Neo-potential of deltoid and supraspinatus/infraspinatus was documented at 4-5 months post surgery. Shoulder abduction (and elbow flexion) was reanimated at 4-8 months post surgery. Significant improvement was observed at 15-36 months post surgery, shoulder abduction regained to 40-160° (mean: 92.5°), muscle strength of supraspinatus/infraspinatus and deltoid were graded to M3-M5 (mean: 4.0 and 4.1); 3 cases muscle strength of elbow flexion was graded from M4 to M5- (mean: 4.4) with 1 case loss. Shoulder shrugging of trapezius was graded to M5 in 5 cases, M5- in 2 cases, M4 in 2 cases and M3 in 1 case (mean: 4.5). All cases showed normal elbow extension and muscle strength of triceps (M5).

CONCLUSION

It is feasible to carry out multiple nerve fascicle transfers for early reconstruction of shoulder abduction by posterior approach. Patients who received this procedure achieved good functional recovery and their donor site morbidity/injury was minimal.

Functional recovery of severe obturator and femoral nerve injuries after lateral retroperitoneal transpsoas surgery

The minimally invasive lateral retroperitoneal transpsoas approach is a popular fusion technique. However, potential complications include injury to the lumbar plexus nerves, bowel, and vasculature, the most common of which are injuries to the lumbar plexus. The femoral nerve is particularly vulnerable because of its size and location; injury to the femoral nerve has significant clinical implications because of its extensive sensory and motor innervation of the lower extremities. The authors present an interesting case of a 49-year-old male patient in whom femoral and obturator nerve functional recovery unexpectedly occurred 364 days after the nerves had been injured during lateral retroperitoneal transpsoas surgery. Chronological video and electrodiagnostic findings demonstrate evidence of recovery. Classification and mechanisms of nerve injury and nerve regeneration are discussed.

A systematic review of nerve transfer and nerve repair for the treatment of adult upper brachial plexus injury

Nerve reconstruction for upper brachial plexus injury consists of nerve repair and/or transfer. Current literature lacks evidence supporting a preferred surgical treatment for adults with such injury involving shoulder and elbow function. We systematically reviewed the literature published from January 1990 to February 2011 using multiple databases to search the following: brachial plexus and graft, repair, reconstruction, nerve transfer, neurotization. Of 1360 articles initially identified, 33 were included in analysis, with 23 nerve transfer (399 patients), 6 nerve repair (99 patients), and 4 nerve transfer + proximal repair (117 patients) citations (mean preoperative interval, 6 ± 1.9 months). For shoulder abduction, no significant difference was found in the rates ratio (comparative probabilities of event occurrence) among the 3 methods to achieve a Medical Research Council (MRC) scale score of 3 or higher or a score of 4 or higher. For elbow flexion, the rates ratio for nerve transfer vs nerve repair to achieve an MRC scale score of 3 was 1.46 (P = .03); for nerve transfer vs nerve transfer + proximal repair to achieve an MRC scale score of 3 was 1.45 (P = .02) and an MRC scale score of 4 was 1.47 (P = .05). Therefore, for elbow flexion recovery, nerve transfer is somewhat more effective than nerve repair; however, no particular reconstruction strategy was found to be superior to recover shoulder abduction. When considering nerve reconstruction strategies, our findings do not support the sole use of nerve transfer in upper brachial plexus injury without operative exploration to provide a clear understanding of the pathoanatomy. Supraclavicular brachial plexus exploration plays an important role in developing individual surgical strategies, and nerve repair (when donor stumps are available) should remain the standard for treatment of upper brachial plexus injury except in isolated cases solely lacking elbow flexion.

Neurotization from two medial pectoral nerves to musculocutaneous nerve in a pediatric brachial plexus injury

Traumatic brachial plexus injuries can be devastating, causing partial to total denervation of the muscles of the upper extremities. Surgical reconstruction can restore motor and/or sensory function following nerve injuries. Direct nerve-to-nerve transfers can provide a closer nerve source to the target muscle, thereby enhancing the quality and rate of recovery. Restoration of elbow flexion is the primary goal for patients with brachial plexus injuries. A 4-year-old right-hand-dominant male sustained a fracture of the left scapula in a car accident. He was treated conservatively. After the accident, he presented with motor weakness of the left upper extremity. Shoulder abduction was grade 3 and elbow flexor was grade 0. Hand function was intact. Nerve conduction studies and an electromyogram were performed, which revealed left lateral and posterior cord brachial plexopathy with axonotmesis. He was admitted to Rehabilitation Medicine and treated. However, marked neurological dysfunction in the left upper extremity was still observed. Six months after trauma, under general anesthesia with the patient in the supine position, the brachial plexus was explored through infraclavicular and supraclavicular incisions. Each terminal branch was confirmed by electrophysiology. Avulsion of the C5 roots and absence of usable stump proximally were confirmed intraoperatively. Under a microscope, neurotization from the musculocutaneous nerve to two medial pectoral nerves was performed with nylon 8-0. Physical treatment and electrostimulation started 2 weeks postoperatively. At a 3-month postoperative visit, evidence of reinnervation of the elbow flexors was observed. At his last follow-up, 2 years following trauma, the patient had recovered Medical Research Council (MRC) grade 4+ elbow flexors. We propose that neurotization from medial pectoral nerves to musculocutaneous nerve can be used successfully to restore elbow flexion in patients with brachial plexus injuries.

Nerve transfer strategies for spinal cord injury

BACKGROUND

Spinal cord injury (SCI) is a devastating condition, which beleaguers its victims with long-term health issues. Nerve transfer is a feasible option for restoration of critical limb function in patients with SCI that potentially improves independence and quality of life.

METHODS

This article delineates the general principles of nerve transfer and its specific application pertinent to SCI. The available nerve transfer strategies are described based on the targeted limb function, mostly involving critical upper extremity function. The role of nerve transfer for paraplegia, diaphragm reanimation, and bladder reinnervation is also discussed.

RESULTS

Nerve transfer offers several advantages over the traditionally used tendon transfer.

CONCLUSIONS

Nerve transfer does not require prolonged immobilization and provides greater functional gain for a given transfer. Reconstruction of several facets of upper limb function potentially can be performed in a single stage. The merits of nerve transfer deserve further study to evaluate its value for spinal cord injury in humans.

Diaphragmatic height index: new diagnostic test for phrenic nerve dysfunction

OBJECT

The diaphragmatic height index (DHI) was developed to measure the difference in diaphragm levels. The purpose of this study was to set definite DHI values and test the accuracy of these values for use as a new diagnostic test for phrenic nerve dysfunction.

METHODS

All data for this study were obtained from medical charts and retrospectively reviewed.

RESULTS

One hundred sixty-five patients with brachial plexus injury who had undergone nerve transfers between 2005 and 2008 were divided into Groups A and B. Group A consisted of 40 patients (mean age 28.0 years) who had sustained concomitant injury of the brachial plexus and phrenic nerves. Patients in Group A1 had right phrenic nerve injury and those in Group A2 had left phrenic nerve injury. Intraoperative direct electrical stimulation of the phrenic nerve was considered the gold standard in assessing nerve function in all patients with brachial plexus injury. Group B consisted of 125 patients (mean age 28.7 years) with brachial plexus injury and normal phrenic nerve function. Group C, the control group, consisted of 80 patients with nonbrachial plexus injury (mean age 34.0 years) who had undergone other kinds of orthopedic operations between April and June 2009. Standard posteroanterior chest radiographs were blindly interpreted using the Siriraj inhouse picture archiving and communication system in all 245 patients in the study. First, a reference line (R line) was drawn along the inferior endplate of T-10. Then, 2 lines (lines A and B) were drawn through the highest point of each diaphragm and parallel to the R line. The difference between these 2 lines divided by the height of T-10 was defined as the DHI. The cutoff points of the DHI for diagnosing right and left phrenic nerve dysfunction were analyzed with a receiver operating characteristic curve. The accuracy of these DHI values was then evaluated. The DHI in Group C was 0.64 ± 0.44, slightly higher than the DHI in Group B, with no significant difference. Diaphragmatic height indexes in Groups A1 and A2 were 2.0 ± 0.99 and -1.04 ± 0.83, respectively, which were significantly different from those in Groups B and C (p < 0.05). The cutoff point of the DHI for diagnosing right phrenic nerve dysfunction was > 1.1, and that for left phrenic nerve dysfunction was < 0.2. The sensitivity and specificity of right and left DHI values were 90.5% and 86.3%, and 94.7 and 88.3%, respectively.

CONCLUSIONS

Data in this study show that diaphragm paralysis can be simply and reliably predicted by the DHI. Diaphragmatic height index values > 1.1 and < 0.2 are proposed as the new diagnostic test for right and left phrenic nerve dysfunction with a high degree of accuracy. This index is applicable in diagnosing phrenic nerve dysfunction that occurs concomitantly with brachial plexus injury or from other etiologies.

Axillary nerve repair by fascicle transfer from the ulnar or median nerve in upper brachial plexus palsy

Object

Nerve repair using motor fascicles of a different nerve was first described for the repair of elbow flexion (Oberlin technique). In this paper, the authors describe their experience with a similar method for axillary nerve reconstruction in cases of upper brachial plexus palsy.

Methods

Of 791 nerve reconstructions performed by the senior author (P.H.) between 1993 and 2011 in 441 patients with brachial plexus injury, 14 involved axillary nerve repair by fascicle transfer from the ulnar or median nerve. All 14 of these procedures were performed between 2007 and 2010. This technique was used only when there was a deficit of the thoracodorsal or long thoracic nerve, which are normally used as donors.

Results

Nine patients were followed up for 24 months or longer. Good recovery of deltoid muscle strength was seen in 7 (77.8%) of these 9 patients, and in 4 patients with less follow-up (14–23 months), for an overall success rate of 78.6%. The procedure was unsuccessful in 2 of the 9 patients with at least 24 months of follow-up. The first showed no signs of reinnervation of the axillary nerve by either clinical or electromyographic evaluation in 26 months of follow-up, and the second had Medical Research Council (MRC) Grade 2 strength in the deltoid muscle 36 months after the operation. The last of the group of 14 patients has had 12 months of follow-up and is showing progressive improvement of deltoid muscle function (MRC Grade 2).

Conclusions

The authors conclude that fascicle transfer from the ulnar or median nerve onto the axillary nerve is a safe and effective method for reconstruction of the axillary nerve in patients with upper brachial plexus injury.

Clinical outcomes following brachialis to anterior interosseous nerve transfers

The surgical management of lower brachial plexus injuries remains a challenging problem. Although nerve transfers have improved clinical outcomes following brachial plexus injuries, the majority of work has focused on upper trunk injuries. Complete lower plexus injuries often lack suitable donors for either nerve or tendon transfers. The authors describe their experience with isolated lower trunk injuries utilizing the nerve to the brachialis to reinnervate the anterior interosseous nerve.

[Isolated traumatic injuries of the axillary nerve. Radial nerve transfer in four cases and literatura review]

OBJECTIVE

To analyze the results of an initial series of four cases of traumatic injuries of the axillary nerve, treated by a nerve transfer from the triceps long branch of the radial nerve. An extensive analysis of the literature has also been made.

MATERIALS AND METHODS

Four patients aged between 21 and 42 years old presenting an isolated traumatic palsy of the axillary nerve were operated between January 2007 and June 2010. All cases were treated by nerve transfer six to eight months after the trauma. The results of these cases are analyzed, the same as the axillary nerve injuries series presented in the literature from 1982.

RESULTS

One year after the surgery, all patients improved their abduction a mean of 70° (range 30 to 120°), showing a M4 in the British Medical Council Scale. No patient complained of triceps weakness after the procedure. These results are similar to those published employing primary grafting for the axillary nerve.

CONCLUSIONS

Isolated injuries of the axillary nerve should be treated with surgery when spontaneous recovery is not verified 6 months after the trauma. Primary repair with grafts is the most popular surgical technique, with a rate of success of approximately 90%. The preliminary results of a nerve transfer employing the long triceps branch are similar, and a definite comparison of both techniques with a bigger number of cases should be done in the future.

Types and severity of operated supraclavicular brachial plexus injuries caused by traffic accidents

BACKGROUND

Brachial plexus injuries occur in up to 5% of polytrauma cases involving motorcycle accidents and in approximately 4% of severe winter sports injuries. One of the criteria for a successful operative therapy is the type of lesion. Upper plexus palsy has the best prognosis, whereas lower plexus palsy is surgically untreatable. The aim of this study was to evaluate a group of patients with brachial plexus injury caused by traffic accidents, categorize the injuries according to type of accident, and look for correlations between type of palsy (injury) and specific accidents.

METHODS

A total of 441 brachial plexus reconstruction patients from our department were evaluated retrospectively(1993 to 2011). Sex, age, neurological status, and the type and cause of injury were recorded for each case. Patients with BPI caused by a traffic accident were assessed in detail.

RESULTS

Traffic accidents were the cause of brachial plexus injury in most cases (80.7%). The most common type of injury was avulsion of upper root(s) (45.7%) followed by rupture (28.2%), complete avulsion (16.9%) and avulsion of lower root(s) (9.2%). Of the patients, 73.9% had an upper,22.7% had a complete and only 3.4% had a lower brachial plexus palsy. The main cause was motorcycle accidents(63.2%) followed by car accidents (23.5%), bicycle accidents(10.7%) and pedestrian collisions (3.1%) (p<0.001).Patients involved in car accidents had a higher percentage of lower avulsion (22.7%) and a lower percentage of upper avulsion (29.3%), whereas cyclists had a higher percentage of upper avulsion (68.6%) based on the data from the entire group of patients (p<0.001). Lower plexus palsy was significantly increased in patients after car accidents (9.3%,p<0.05). In the two main groups (car and motorcycle accidents),significantly more upper and fewer lower palsies were present. In the bicycle accident group, upper palsy was the most common (89%).

CONCLUSION

Study results indicate that the most common injury was an upper plexus palsy. It was characteristic of bicycle accidents, and significantly more common in car and motorcycle accidents. The results also indicate that it is important to consider the potential of a brachial plexus injury after serious traffic accidents and to examine both upper extremities in detail even if some motor function is preserved.

Medial pectoral nerve to axillary nerve neurotization following traumatic brachial plexus injuries: indications and clinical outcomes

INTRODUCTION

The medial pectoral nerve (MPN) represents a viable donor nerve for neurotization procedures for restoration of shoulder function following upper trunk brachial plexus injuries.

MATERIALS AND METHODS

We report an eight-case series, single-surgeon experience of patients with upper trunk brachial plexus injuries who underwent MPN to axillary nerve (AXN) transfer from 2001-2007 for shoulder stability and abduction.

RESULTS

The mean patient age was 31.5 (range, 19-51 years). The mean follow-up for all patients was 22.25 ± 7.4 months. Surgery was performed at a mean of 5.8 ± 2.9 months post-injury. On initial evaluation, all eight patients had no deltoid function (M0). Of the eight patients examined postoperatively, we observed excellent recovery in four, good recovery in two, fair recovery in one, and poor functional recovery in the remaining patient.

DISCUSSION

MPN to AXN neurotization is a valid surgical option in the restoration of shoulder stability and shoulder abduction following trauma-related upper trunk brachial plexus injury.

Spinal cord bypass surgery with intercostal and spinal accessory nerves: an anatomical feasibility study in human cadavers

OBJECT

Despite extensive study, no meaningful progress has been made in encouraging healing and recovery across the site of spinal cord injury (SCI) in humans. Spinal cord bypass surgery is an unconventional strategy in which intact peripheral nerves rostral to the level of injury are transferred into the spinal cord below the injury. This report details the feasibility of using spinal accessory nerves to bypass cervical SCI and intercostal nerves to bypass thoracolumbar SCI in human cadavers.

METHODS

Twenty-three human cadavers underwent cervical and/or lumbar laminectomy and dural opening to expose the cervical cord and/or conus medullaris. Spinal accessory nerves were harvested from the Erb point to the origin of the nerve's first major branch into the trapezius. Intercostal nerves from the T6-12 levels were dissected from the lateral border of paraspinal muscles to the posterior axillary line. The distal ends of dissected nerves were then transferred medially and sequentially inserted 4 mm deep into the ipsilateral cervical cord (spinal accessory nerve) or conus medullaris (intercostals). The length of each transferred nerve was measured, and representative distal and proximal cross-sections were preserved for axonal counting.

RESULTS

Spinal accessory nerves were consistently of sufficient length to be transferred to caudal cervical spinal cord levels (C4-8). Similarly, intercostal nerves (from T-7 to T-12) were of sufficient length to be transferred in a tension-free manner to the conus medullaris. Spinal accessory data revealed an average harvested nerve length of 15.85 cm with the average length needed to reach C4-8 of 4.7, 5.9, 6.5, 7.1, and 7.8 cm. The average length of available intercostal nerve from each thoracic level compared with the average length required to reach the conus medullaris in a tension-free manner was determined to be as follows (available, required in cm): T-7 (18.0, 14.5), T-8 (18.7, 11.7), T-9 (18.8, 9.0), T-10 (19.6, 7.0), T-11 (18.8, 4.6), and T-12 (15.8, 1.5). The number of myelinated axons present on cross-sectional analysis predictably decreased along both spinal accessory and intercostal nerves as they coursed distally.

CONCLUSIONS

Both spinal accessory and intercostal nerves, accessible from a posterior approach in the prone position, can be successfully harvested and transferred to their respective targets in the cervical spinal cord and conus medullaris. As expected, the number of axons available to grow into the spinal cord diminishes distally along each nerve. To maximize axon "bandwidth" in nerve bypass procedures, the most proximal section of the nerve that can be transferred in a tension-free manner to a spinal level caudal to the level of injury should be implanted. This study supports the feasibility of SAN and intercostal nerve transfer as a means of treating SCI and may assist in the preoperative selection of candidates for future human clinical trials of cervical and thoracolumbar SCI bypass surgery.

Nerve surgery and gene therapy: a neurobiological and clinical perspective

Despite major microsurgical improvements the clinical outcome of peripheral nerve surgery is still regarded as suboptimal. Over the past decade several innovative techniques have been developed to extend the armamentarium of the nerve surgeon. This review evaluates the potential of gene therapy in the context of peripheral nerve repair. First the main challenges impeding peripheral nerve regeneration are presented. This is followed by a short introduction to gene therapy and an overview of its most important advantages over the classical delivery of therapeutic proteins. Next, this review focuses on the most promising viral vectors capable of targeting the peripheral nervous system and their first application in animal models. In addition, the challenges of translating these experimental results to the clinic, the limitations of current vectors and the further developments needed, are discussed. Finally, four strategies are presented on how gene therapy could help patients that have to undergo reconstructive nerve surgery in the future.

Use of long autologous nerve grafts in brachial plexus reconstruction: factors that affect the outcome

BACKGROUND

Using grafts directed to distal targets in brachial plexus reconstruction has the advantage over proximal targets of avoiding axonal dispersion. A long graft (more than 10 cm) is needed to reach most distal targets. The objective of this article is to identify factors associated with good versus poor outcomes in a clinical series of long grafts used for distal brachial plexus reconstruction.

METHODS

In 34 patients with a flail arm, 47 sural grafts >10 cm long were followed for ≥2 years postoperatively. Surgical technique included standard supraclavicular exposure of the proximal brachial plexus and its branches, the phrenic nerve and spinal accessory nerve. Distal target nerves were exposed via an incision starting at the axilla, following the gap between the biceps and triceps. Cases achieving a good result were statistically compared against those with a poor result as to the donor nerve/root, target nerve, patient age and weight, time from trauma to surgery, graft length and long-term rehabilitation quality.

FINDINGS

A good outcome was observed with 23 grafts (48.9%), but 66.7% of the 30 long grafts done within 6 months of trauma yielded a good result. Only 1 of 15 patients with the lowest quality rehabilitation score experienced a good result (6.6%) versus all 12 patients with the highest rating (p < 0.001). Trauma-to-surgery time was roughly half as long in those with a good result (4.7 vs. 9.0 months, p < 0.001). No other inter-group differences were observed.

CONCLUSIONS

The results of a series of distal brachial plexus target reinnervations with long grafts is presented and analyzed. According to them, time from trauma to surgery and an adequate postoperative rehabilitation are important predictors of outcome.

Modified C-7 neurotization in the treatment of brachial plexus avulsion injury

Object

Contralateral C-7 transfer is often used in patients with brachial plexus avulsion injury. Traditionally, the contralateral C-7 root has only been transferred to a single nerve, such as the median or radial nerve. In this study, the authors aimed to evaluate the efficacy of contralateral C-7 transfer to 2 different recipient nerves in patients with brachial plexus avulsion injuries.

Methods

Between 2004 and 2008, 10 patients with brachial plexus root avulsions underwent nerve reconstruction using a modified C-7 neurotization technique. In this procedure, the contralateral C-7 root was transferred via vascularized ulnar nerve grafts to both the musculocutaneous nerve and the median nerve on the affected side.

Results

The strength of the biceps muscles increased to M3 or M4 in 6 patients and to M2 in 2 patients. The median nerve transfers led to regained motor function and strength of the wrist and finger flexors with improvement to M3 in 5 patients. Seven patients showed notable gains of sensory function (≥ S3).

Conclusions

Contralateral C-7 transfer to 2 different recipient nerves is a feasible and efficient approach in patients with brachial plexus avulsion injuries when the donor nerve is limited.

Computer simulation of nerve transfer strategies for restoring shoulder function after adult C5 and C6 root avulsion injuries

PURPOSE

Functional ability after nerve transfer for upper brachial plexus injuries relies on both the function and magnitude of force recovery of targeted muscles. Following nerve transfers targeting either the axillary nerve, suprascapular nerve, or both, it is unclear whether functional ability is restored in the face of limited muscle force recovery.

METHODS

We used a computer model to simulate flexing the elbow while maintaining a functional shoulder posture for 3 nerve transfer scenarios. We assessed the minimum restored force capacity necessary to perform the task, the associated compensations by neighboring muscles, and the effect of altered muscle coordination on movement effort.

RESULTS

The minimum force restored by the axillary, suprascapular, and combined nerve transfers that was required for the model to simulate the desired movement was 25%, 40%, and 15% of the unimpaired muscle force capacity, respectively. When the deltoid was paralyzed, the infraspinatus and subscapularis muscles generated higher shoulder abduction moments to compensate for deltoid weakness. For all scenarios, movement effort increased as restored force capacity decreased.

CONCLUSIONS

Combined axillary and suprascapular nerve transfer required the least restored force capacity to perform the desired elbow flexion task, whereas single suprascapular nerve transfer required the most restored force capacity to perform the same task. Although compensation mechanisms allowed all scenarios to perform the desired movement despite weakened shoulder muscles, compensation increased movement effort. Dynamic simulations allowed independent evaluation of the effect of restored force capacity on functional outcome in a way that is not possible experimentally.

CLINICAL RELEVANCE

Simultaneous nerve transfer to suprascapular and axillary nerves yields the best simulated biomechanical outcome for lower magnitudes of muscle force recovery in this computer model. Axillary nerve transfer performs nearly as well as the combined transfer, whereas suprascapular nerve transfer is more sensitive to the magnitude of reinnervation and is therefore avoided.

Transfer of the Distal Terminal Motor Branch of the Extensor Carpi Radialis Brevis to the Nerve of the Flexor Pollicis Longus

BACKGROUND:

In tetraplegics, thumb and finger motion traditionally has been reconstructed via orthopedic procedures. Although rarely used, nerve transfers are a viable method for reconstruction in tetraplegia.

OBJECTIVE:

To investigate the anatomic feasibility of transferring the distal branch of the extensor carpi radialis brevis (ECRB) to the flexor pollicis longus (FPL) nerve and to report our first clinical case.

METHODS:

We studied the motor branch of the ECRB and FPL in 14 cadaveric upper limbs. Subsequently, a 24-year-old tetraplegic man with preserved motion in his shoulder, elbow, wrist, and finger extension, but paralysis of thumb and finger flexion underwent surgery. Seven months after trauma, we transferred the brachialis muscle with a tendon graft to the flexor digitorum profundus. The distal nerve of the ECRB was transferred to the FPL nerve.

RESULTS:

The branch to the ECRB entered the muscle in its anterior and proximal third. After sending out a first collateral, the nerve runs for 2.4 cm alongside the muscle and bifurcates intramuscularly. A main branch from the anterior interosseous nerve, which entered the muscle 3 cm from its origin on the radius, innervated the FPL. The ECRB and FPL nerves had similar diameters (∼1 mm) and numbers of myelinated fibers (∼180). In our patient, 14 months after surgery, pinching and grasping were restored and measured 2 and 8 kg strength, respectively.

CONCLUSION:

Transfer of the ECRB distal branch to the FPL is a viable option to reconstruct thumb flexion.

Functional restoration of the paralyzed diaphragm in high cervical quadriplegia via phrenic nerve neurotization utilizing the functional spinal accessory nerve

The authors report a case of functional improvement of the paralyzed diaphragm in high cervical quadriplegia via phrenic nerve neurotization using a functional spinal accessory nerve. Complete spinal cord injury at the C-2 level was diagnosed in a 44-year-old man. Left diaphragm activity was decreased, and the right diaphragm was completely paralyzed. When the level of metabolism or activity (for example, fever, sitting, or speech) slightly increased, dyspnea occurred. The patient underwent neurotization of the right phrenic nerve with the trapezius branch of the right spinal accessory nerve at 11 months postinjury. Four weeks after surgery, training of the synchronous activities of the trapezius muscle and inspiration was conducted. Six months after surgery, motion was observed in the previously paralyzed right diaphragm. The lung function evaluation indicated improvements in vital capacity and tidal volume. This patient was able to sit in a wheelchair and conduct outdoor activities without assisted ventilation 12 months after surgery.

Neurotization of the phrenic nerve with accessory nerve: a new strategy for high cervical spinal cord injury with respiratory distress

The prevalence of high cervical spinal cord injury has been rising and the life quality of these survivors remains poor. Even though mechanical ventilation prolongs their lifespans, the complications of mechanical obstruction and infection always perplex the doctors and patients. While phrenic nerve pacing was developed to improve the survival quality of them and have an analogous negative pressure mechanism. Herein we postulate that a potential physiological respiration may be resulted from neurotization of the phrenic nerve with accessory nerve. Once the potential strategy can be succeeded in the clinical application, patients will acquire remarkable survival profit.

Transfer of the Platysma Motor Branch to the Accessory Nerve in a Patient With Trapezius Muscle Palsy and Total Avulsion of the Brachial Plexus

BACKGROUND AND IMPORTANCE:

To report on the successful use of a platysma motor nerve transfer to the accessory nerve in a patient with concomitant trapezius and brachial plexus palsy.

CLINICAL PRESENTATION:

A 20-year-old man presented with total avulsion of the right brachial plexus combined with palsies of the accessory and phrenic nerve. The patient was operated on 4 months after his injury. The accessory nerve was repaired via direct transfer of the platysma motor branch. The contralateral C7 root was connected to the musculocutaneous nerve, and the hemihypoglossal nerve was grafted to the suprascapular nerve. Two intercostal nerves were attached to the triceps long head motor branch.

CONCLUSION:

Within 20 months of surgery, the patient regained full reinnervation of the upper trapezius muscle. Elbow flexion scored M3+, and 30° active shoulder abduction was observed. Triceps reinnervation was poor. Platysma motor branch transfer to the accessory nerve is a viable alternative to reinnervate the trapezius muscle.

Inducible nerve growth factor delivery for peripheral nerve regeneration in vivo

BACKGROUND

HEK-293 cells can be genetically modified to release and regulate nerve growth factor (NGF) in vitro. The aim of this study was to evaluate the impact of this NGF delivery system on peripheral nerve regeneration in vivo.

METHODS

HEK-293 cells were transfected with an ecdysone receptor, NGF cDNA, and herpes simplex virus-thymidine kinase suicide vector. NGF production is induced by ponasterone A and stopped by ganciclovir. A 13-mm sciatic nerve gap was bridged with Silastic conduits in 120 nude rats, and transfected HEK-293 cells were added, induced, and boostered to secrete bioactive NGF.

RESULTS

The induction of the cell line and additional booster with ponasterone A demonstrated significantly higher levels of bioactive NGF, enhanced macroscopic nerve growth, improved functional recovery, and histologic regeneration when compared with control groups after 7, 14, and 21 days, and 2 and 4 months. The treatment with ganciclovir resulted in suppression of the NGF production and decreased functional and histologic outcomes.

CONCLUSIONS

Transfected HEK-293 cells can be regulated to inducibly produce bioactive NGF in vivo over prolonged periods. This tissue-engineered nerve construct including the NGF delivery system is able to improve peripheral nerve regeneration and functional recovery and appears to be superior to nerve isografts.

Nerve reconstruction: A cohort study of 93 cases of global brachial plexus palsy

INTRODUCTION

Brachial plexus injury leading to flail upper limb is one of the most disabling injuries. Neglect of the injury and delay in surgeries may preclude reinnervation of the paralysed muscles. Currently for such injuries nerve transfers are the preferred procedures. We here present a series of 93 cases of global brachial plexus palsy treated with nerve transfers.

MATERIALS AND METHODS

Ninety-three cases of global palsies out of 384 cases of brachial plexus injury operated by the senior surgeon (AB) were selected. Age varied from 4 to 51 years with 63 patients in 20 to 40 age group and all patients having a minimum follow up of at least 1 year post surgery ranging up to 130 months. The delay before surgery ranged from 15 days to 16 months (mean 3.2 months). The aim of the surgery was to restore the elbow flexion, shoulder abduction, triceps function and wrist and finger flexion in that order of priority. The major nerve transfers used were spinal accessory to suprascapular nerve, intercostal to musculocutaneous nerve and pectoral nerves, contralateral C7 to median and radial nerves. Nerve stumps were used whenever available (30 patients).

RESULTS

Recovery of ≥ grade 3 power was noted in biceps in 73% (68/93) of patients, shoulder abduction in 89% (43/49), pectoralis major in 100% (8/8). Recovery of grade 2 triceps power was seen in 80% (12/16) patients with nerve transfer to radial nerve. Derotation osteotomies of humerus (n=13) and wrist fusion (n=14) were the most common secondary procedures performed to facilitate alignment and movements of the affected limb. Better results were noted in 59 cases where direct nerve transfers were done (without nerve graft).

CONCLUSION

Acceptable function (restoration of biceps power ≥3) can be obtained in more than two thirds (73%) of these global brachial plexus injuries by using the principles of early exploration and nerve transfer with rehabilitation.

Construction of tissue engineered nerve grafts and their application in peripheral nerve regeneration

Surgical repair of severe peripheral nerve injuries represents not only a pressing medical need, but also a great clinical challenge. Autologous nerve grafting remains a golden standard for bridging an extended gap in transected nerves. The formidable limitations related to this approach, however, have evoked the development of tissue engineered nerve grafts as a promising alternative to autologous nerve grafts. A tissue engineered nerve graft is typically constructed through a combination of a neural scaffold and a variety of cellular and molecular components. The initial and basic structure of the neural scaffold that serves to provide mechanical guidance and optimal environment for nerve regeneration was a single hollow nerve guidance conduit. Later there have been several improvements to the basic structure, especially introduction of physical fillers into the lumen of a hollow nerve guidance conduit. Up to now, a diverse array of biomaterials, either of natural or of synthetic origin, together with well-defined fabrication techniques, has been employed to prepare neural scaffolds with different structures and properties. Meanwhile different types of support cells and/or growth factors have been incorporated into the neural scaffold, producing unique biochemical effects on nerve regeneration and function restoration. This review attempts to summarize different nerve grafts used for peripheral nerve repair, to highlight various basic components of tissue engineered nerve grafts in terms of their structures, features, and nerve regeneration-promoting actions, and finally to discuss current clinical applications and future perspectives of tissue engineered nerve grafts.

Fascicular Topography of the Suprascapular Nerve in the C5 Root and Upper Trunk of the Brachial Plexus: A Microanatomic Study From a Nerve Surgeon's Perspective

BACKGROUND:

In patients with supraclavicular injuries of the brachial plexus, the suprascapular nerve (SSN) is frequently reconstructed with a sural nerve graft coapted to C5. As the C5 cross-sectional diameter exceeds the graft diameter, inadequate positioning of the graft is possible.

OBJECTIVE:

To identify a specific area within the C5 proximal stump that contains the SSN axons and to determine how this area could be localized by the nerve surgeon, we conducted a microanatomic study of the intraplexal topography of the SSN.

METHODS:

The right-sided C5 and C6 roots, the upper trunk with its divisions, and the SSN of 20 adult nonfixed cadavers were removed and fixed. The position and area occupied by the SSN fibers inside C5 were assessed and registered under magnification.

RESULTS:

The SSN was monofascicular in all specimens and derived its fibers mainly from C5. Small contributions from C6 were found in 12 specimens (60%). The mean transverse area of C5 occupied by SSN fibers was 28.23%. In 16 specimens (80%), the SSN fibers were localized in the ventral (mainly the rostroventral) quadrants of C5, a cross-sectional area between 9 o'clock and 3 o'clock from the surgeon's intraoperative perspective.

CONCLUSION:

In reconstruction of the SSN with a sural nerve graft, coaptation should be performed in the rostroventral quadrant of C5 cross-sectional area (between 9 and 12 o'clock from the nerve surgeon's point of view in a right-sided brachial plexus exploration). This will minimize axonal misrouting and may improve outcome.

Anatomic study in cadaver of the motor branch of the musculocutaneous nerve

This study of 80 cadavers demonstrates that the anatomic position of the motor branch of the musculocutaneous nerve with respect to that of the sensitive branch of the same nerve is lateral in more than 88% of cases in humans.The distance from plexus to the separation into the motor and sensitive fascicles was 8-9 cm long.Given the lateral position of the motor component of the musculocutaneous nerve, the nerves that are going to be used to neurotize this area can be directed so as to increase the efficacy of the results for the flexor function of the arm.

INTRODUCTION

Brachial plexus lesions produce great morbidity and are relatively frequent in young adults. Innervating the coracobrachial, biceps and anterior brachial muscles, the musculocutaneous nerve is one of the priorities for nerve neurotization when plexus root avulsion occurs because it is essential for arm flexion. This nerve has both a motor and sensitive component, and the anatomic positions of the two components have not been much studied. When performing a neurotization anastomosis to the musculocutaneous nerve, being able to identify the motor component of the graft and attach it to the motor component of the musculocutaneous nerve could avoid a loss of many motor axons which would otherwise occur if the graft were attached to the sensitive component.

OBJECTIVE

The present paper is based on a topographic anatomic study to locate and obtain the objective positioning of the motor branch of the musculocutaneous nerve in humans, as well as measure its length from the origin in the brachial plexus to the separation of both fascicles into branches.

MATERIAL AND METHODS

The study was performed in 40 cadavers, dissecting the musculocutaneous nerve along its course and measuring the distance from its emergence from the plexus until the separation between its motor and sensitive branches in both arms so as to be able to determine the positioning of the motor fascicle with respect to the sensitive fascicle.

RESULTS

The distance from plexus to the separation into the motor and sensitive fascicles was 8.8 cm on the left side and 8.95 cm on the right side. The position of the motor branch with respect to the sensitive branch was lateral in more than 85% of the studied nerves, all the way from its origin in the brachial plexus until the definitive separation between both branches, on both the right and the left sides.

CONCLUSION

If the nerves that are to be used for neurotization of the musculacutaneous nerve are directly taken to the lateral fascicle of that nerve, which is generally the motor component, the treatment should be effective and should avoid the loss of motor axons resulting from anastomosing to the sensitive fascicle.

Novel strategies in brachial plexus repair after traumatic avulsion

Clinical trials in spinal cord injury (SCI) can be affected by many confounding variables including spontaneous recovery, variation in the lesion type and extend. However, the clinical need and the paucity of effective therapies has spawned a large number of animal studies and clinical trials for SCI. In this review, we suggest that brachial plexus avulsion injury, a longitudinal spinal cord lesion, is a simpler model to test methods of spinal cord repair. We explore reconstructive techniques currently explored for the repair of brachial plexus avulsion and focus on the use of olfactory ensheathing cell transplantation as an adjunct treatment in brachial plexus repair.

Phrenic nerve transfer for elbow flexion and intercostal nerve transfer for elbow extension

PURPOSE

To explore long-term recovery of elbow flexion and extension after transferring the phrenic nerve and intercostal nerves, respectively, in adults with global brachial plexus avulsion injuries.

METHODS

Seven adults with global brachial plexus avulsion injuries had the phrenic nerve transferred to the musculocutaneous nerve (or to the anterior division of upper trunk) and intercostal nerves transferred to the triceps branch of the radial nerve at our hospital 7 to 12 years ago. The results of elbow motor strength testing using the Medical Research Council grading scale, and electrodiagnostic findings using electromyogram examinations, were studied retrospectively. Pulmonary function tests were also performed at final visits.

RESULTS

Functional elbow flexion was obtained in most of the 7 cases (M2, 1; M3, 3; M4, 2; and M5, 1) but elbow extension was absent or insufficient in all subjects (M0, 1; M1, 3; and M2, 3). Electrical results showed successful biceps reinnervation in 6 patients and successful triceps reinnervation in 5. No patient experienced breathing problems, and pulmonary function results were within normal range.

CONCLUSIONS

In the long term, after brachial plexus avulsion injury in most patients who underwent both phrenic nerve and intercostal nerve transfer to achieve elbow flexion and extension eventually obtained satisfactory elbow flexion but poor elbow extension. We recommend against transferring the intercostal nerves to the triceps branch of radial nerve in conjunction with primary phrenic to musculocutaneous nerve transfer.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Trends in median, ulnar, radial, and brachioplexus nerve injuries in the United States

significant constraints on an individual's quality of life.

OBJECTIVE

To promote efforts to reduce exposure to injury risk factors and to utilize effective therapies when damage does occur, it is important to understand historical trends in both the demographics of peripheral nerve injury (PNI) patients and their treatment. We sought to examine some of these trends.

METHODS

We searched the Nationwide Inpatient Sample for discharges classified with International Classification of Diseases, Ninth Revision diagnosis codes of median, ulnar, radial, or brachioplexus nerve injury between 1993 and 2006. We analyzed these data to obtain trend information for the number of discharges, hospital charges, treatment course, patient demographics, and other measures.

RESULTS

Although aggregate discharges involving these injuries decreased slightly between 1993 and 2006, mean nominal hospital charges for their treatment increased significantly, in particular, for brachial plexus injuries. In 2006 30 to 40% of median, ulnar, and radial nerve injuries required acute repair by direct nerve suture. PNI patients in 2006 were more likely to be male, between the ages of 18 and 44 years, and from regions where the median income level is greater than $36 000. Approximately 75% of PNIs were treated in academic hospitals and 95% in metropolitan areas.

CONCLUSION

PNIs are complex injuries that primarily affect males in key years of adulthood, frequently requiring high-cost acute surgical repair. Although there has been a slight decline in their incidence in the past decade, treatment cost has increased.

Obturator Nerve Transfer as an Option for Femoral Nerve Repair

OBJECTIVE

Nerve transfers have proved to be an important addition to the armamentarium in the repair of brachial plexus lesions, but have been used sparingly for lower extremity nerve repair. Here, we present what is believed to be the first description of a successful transfer of the obturator nerve to the femoral nerve.

CLINICAL PRESENTATION

A 45-year-old woman presented with a complete femoral nerve lesion after removal of a large (15-cm) schwannoma of the retroperitoneum involving the lumbar plexus.

INTERVENTION

The obturator nerve was transferred to the distal stump of the femoral nerve in the retroperitoneal space at the inguinal ligament three months post-injury. At 2 years post-repair, the patient demonstrated 4 out of 5 return (Medical Research Council grade) of quadriceps function and was able to walk nearly normally.

CONCLUSION

In cases in which there are extensive gaps in the femoral nerve, transfer of the obturator nerve provides an option to traditional nerve graft repair.

Proximal motor branches from the tibial nerve as direct donors to restore function of the deep fibular nerve for treatment of high sciatic nerve injuries: a cadaveric feasibility study

OBJECTIVE

The results of surgical repair of the fibular division of the sciatic nerve have been considered unsatisfactory, especially if grafts are necessary to reconstruct the nerve. To consider the clinical application of the concept of distal nerve transfer for the treatment of high sciatic nerve injuries, this study aimed to determine detailed anatomic data about the possible donor branches from the tibial nerve that are available for reinnervation of the deep fibular nerve at the level of the popliteal fossa.

METHODS

An anatomic study was performed that included the dissection of the popliteal fossa in 12 lower limbs of 6 formalin-fixed adult cadavers. It focused on the detailed anatomy of the tibial nerve and its branches at the level of the proximal leg as well as the anatomy of the common fibular nerve and its largest divisions at the level of the neck of the fibula, i.e., the deep and superficial fibular nerves.

RESULTS

The branches of the tibial nerve destined to the lateral and medial head of the gastrocnemius had a mean length of 43 mm and 35 mm, respectively. The branch to the posterior soleus muscle had a mean length of 65 mm. Intraneural dissection of the common fibular nerve, isolating its deep and superficial fibular divisions, was possible to a proximal mean distance of 71 mm. A tensionless direct suture to the deep fibular nerve was made possible by using the nerve to the lateral head of the gastrocnemius and the nerve to the posterior soleus muscle in all specimens. Direct suture of the nerve to the medial head of the gastrocnemius was possible in all cases except 1.

CONCLUSION

The nerve to the lateral and medial heads of the gastrocnemius and the nerve to the posterior soleus muscle can be used as donors to restore function of the deep fibular nerve in cases of high sciatic nerve injury. However, proximal intraneural dissection of the deep fibular division of the common fibular nerve must also be performed. We recommend that the nerve to the posterior soleus muscle should be the first choice for a donor in the proposed transfer.

Shoulder reanimation in posttraumatic brachial plexus paralysis

INTRODUCTION

Posttraumatic brachial plexus paralysis invariably involves the upper roots leading to paralysis of the shoulder region musculature. Early neurotisation of the suprascapular and the axillary nerve should be one of the priorities in plexus reconstruction in order to reanimate the shoulder.

PATIENTS AND METHODS

From 1998 to 2007, 78 patients with posttraumatic brachial plexus palsy were operated in our department. Forty-three patients presented with supraclavicular lesions with involvement of C5 and C6 roots in all cases. Reconstruction of the shoulder function was achieved with neurotisation of the suprascapular nerve in 41 patients. Extraplexus donors were utilised in 34 patients, while intraplexus donors via nerve grafts in 7 patients. Neurotisation of the axillary nerve was performed in 25 patients, utilising intraplexus donors in 16 patients, extraplexus donors in 4, and combination of intraplexus and extraplexus donors in 5 patients.

RESULTS

Suprascapular nerve neurotisation gave good or excellent results (supraspinatus>M3+ or shoulder abduction>40 degrees) in 35 patients. Intraplexus donors regained good or excellent function in 5 out of 6 patients (83%), while extraplexus neurotisations achieved good or excellent function of the supraspinatus in 30 out of 34 patients (88%). Axillary nerve neurotisation offered good or excellent results (deltoid>M3+ or shoulder abduction>60 degrees) in 14 patients (58%). Direct neurotisation of the axillary nerve via the motor branch for the long head of the triceps gave shoulder abduction of >110 degrees, as well as external rotation of >30 degrees in 3 out of 5 patients. Combined neurotisation of suprascapular and axillary nerves gave the best outcome achieving shoulder abduction of >60 degrees as well as external rotation of >30 degrees.

CONCLUSIONS

Shoulder reanimation should be one of the first priorities in brachial plexus reconstruction. Early neurotisation of the suprascapular, and if possible the axillary nerve offers the best outcome.

Current concepts in the management of brachial plexus birth palsy

Brachial plexus birth palsy, although rare, may result in substantial and chronic impairment. Physiotherapy, microsurgical nerve reconstruction, secondary joint corrections, and muscle transpositions are employed to help the child maximize function in the affected upper extremity. Many present controversies regarding natural history, microsurgical treatment, and secondary shoulder reconstructive surgery remain unresolved in infants with brachial plexus birth palsies. Recent literature has enhanced our understanding of the pathoanatomy and natural history of the injury as well as the surgical indications, expected outcomes, and complications; this literature has led to improved care of these patients. Based on the present evidence, recommendations for both microsurgery and shoulder reconstruction with tendon transfer and arthroscopic and open reductions are presented.

Transfer of pectoral nerves to suprascapular and axillary nerves: an anatomic feasibility study

PURPOSE

We conducted an anatomic study to provide detailed information on the pectoral nerves and anatomic data on the transfer of the pectoral nerves to the axillary nerve. Moreover, we experimentally determined the feasibility of transferring the pectoral nerves to the suprascapular nerve in upper brachial plexus injury.

METHODS

We dissected 26 brachial plexus from 15 fresh cadavers. The origin, location, course, and branching of the pectoral nerves were recorded. The length and the diameter of the pectoral nerves were measured. The diameter of the suprascapular and axillary nerves was recorded. In all dissections, we assessed the feasibility of directly transferring the pectoral nerves to the suprascapular and axillary nerves.

RESULTS

We found 3 constant branches of pectoral nerves arising from 3 distinct origins in 20 cases, and 3 constant branches arising from 2 distinct origins in 6 cases. The C7 sent nerve fibers to all 3 branches. The average length and diameter of the superior, middle, and inferior branches of the pectoral nerves were 65 mm, 110 mm, and 105 mm, and 2.0 mm, 2.3 mm, ad 2.4 mm, respectively. The average diameter of the suprascapular and axillary were 2.8 mm and 3.6 mm, respectively. The superior branch reached the suprascapular and axillary nerves in 17 and 8 cases. The middle and inferior branches reached the suprascapular and axillary nerve in all dissections.

CONCLUSIONS

With an adequate length, diameter, and nerve composition, the middle and inferior branches of the pectoral nerves are suitable donor nerves to the axillary nerve and a potential source of reinnervation of the suprascapular nerve in upper brachial plexus injury.

Clinical and neuropathological study about the neurotization of the suprascapular nerve in obstetric brachial plexus lesions

Background

The lack of recovery of active external rotation of the shoulder is an important problem in children suffering from brachial plexus lesions involving the suprascapular nerve. The accessory nerve neurotization to the suprascapular nerve is a standard procedure, performed to improve shoulder motion in patients with brachial plexus palsy.

Methods

We operated on 65 patients with obstetric brachial plexus palsy (OBPP), aged 5-35 months (average: 19 months). We assessed the recovery of passive and active external rotation with the arm in abduction and in adduction. We also looked at the influence of the restoration of the muscular balance between the internal and the external rotators on the development of a gleno-humeral joint dysplasia. Intraoperatively, suprascapular nerve samples were taken from 13 patients and were analyzed histologically.

Results

Most patients (71.5%) showed good recovery of the active external rotation in abduction (60°-90°). Better results were obtained for the external rotation with the arm in abduction compared to adduction, and for patients having only undergone the neurotization procedure compared to patients having had complete plexus reconstruction. The neurotization operation has a positive influence on the glenohumeral joint: 7 patients with clinical signs of dysplasia before the reconstructive operation did not show any sign of dysplasia in the postoperative follow-up.

Conclusion

The neurotization procedure helps to recover the active external rotation in the shoulder joint and has a good prevention influence on the dysplasia in our sample. The nerve quality measured using histopathology also seems to have a positive impact on the clinical results.

Spinal cord bypass surgery using peripheral nerve transfers: review of translational studies and a case report on its use following complete spinal cord injury in a human. Experimental article

Spinal cord injury has been studied in a variety of in vitro and in vivo animal models. One promising therapeutic approach involves the transfer of peripheral nerves originating above the level of injury into the spinal cord below the level of injury. A model of spinal cord injury in rodents has shown the growth of peripheral nerve fibers into the spinal cord, with the subsequent development of functional synaptic connections and limb movement. The authors of this paper are currently developing a similar model in felines to assess the cortical control of these novel repair pathways. In an effort to determine whether these neurotization techniques could translate to spinal cord injury in humans, the authors treated a patient by using intercostal nerve transfer following complete acute spinal cord injury. The case presented details a patient with paraplegia who regained partial motor and sensory activity following the transfer of intercostal nerves, originating above the level of the spinal cord injury, into the spinal canal below the level of injury. The patient recovered some of his motor and sensory function. Notably, his recovered hip flexion showed respiratory variation. This finding raises the possibility that intercostal nerve transfers may augment neurological recovery after complete spinal cord injury.

Medial pectoral nerve to musculocutaneous nerve neurotization for the treatment of persistent birth-related brachial plexus palsy: an 11-year institutional experience

OBJECT

Medial pectoral nerve (MPN) to musculocutaneous nerve (MCN) neurotization for recovery of elbow flexion by biceps reinnervation is a valid option following traumatic injury to the upper brachial plexus. A major criticism of the application of this technique in infants is the smaller size of the MPN and mismatch of viable axons. We describe our institutional experience utilizing this procedure and critically examine functional outcomes.

METHODS

Office charts and hospital records of children from over an 11-year period beginning January 1997 were reviewed. Of the 53 children of various ages undergoing brachial plexus exploration for traumatic injury of any nature, 20 underwent MPN to MCN neurotization as a part of an overall procedure in the first year of life to treat birth-related brachial plexus palsy and had at least 9 months' follow-up. Medial pectoral nerve to MCN neurotization was chosen if the results of clinical examination and intraoperative electrophysiological evidence were consistent with medial cord function. Functional recovery was defined as the ability of the child to bring their hand to their mouth.

RESULTS

Sixteen patients (80%) gained functional recovery. The median age at surgery was 7 months. Median time to first clinic visit documenting recovery was 11.5 months and median overall follow up was 21.5 months. Preoperative hand function was a useful predictor of recovery of elbow flexion.

CONCLUSIONS

Medial pectoral nerve to MCN neurotization is a valid surgical option for the reinnervation of the biceps muscle for birth-related brachial plexus palsy when the hand is functional preoperatively. Useful elbow flexion can be expected in the majority of these children.