Direct Nerve Repair Research Articles

Recent advances in nerve repair.

Peripheral nerve injuries are extremely devastating, and their management is exceedingly complex. Microsurgical repair is the mainstay of treatment and this includes direct nerve repair, nerve grafts, nerve tubes and nerve transfers. Today, nerve transfers are being widely performed due to an increased understanding of cortical plasticity, motor re-education and perioperative rehabilitation, and they are now known to produce excellent functional outcomes. This manuscript reviews the current strategies for nerve repair, including comments on outcomes, with special emphasis on existing nerve transfer techniques.

Testing of Direct Neurorrhaphy Strain

To investigate the ideal suture material to test strain at nerve repair sites. Based on nerve strain tolerance, we aimed to determine which suture reliably failed by an average of 5% and a maximum of 8% strain when loaded to failure. The median nerve of 19 cadavers was exposed in the distal forearm, transected proximally, and attached to a spring gauge. It was marked 5 cm on either side of its midpoint to measure strain. A laceration was created at its midpoint. We performed a tension-free end-to-end repair with a single epineural suture. Load to failure of the repair site was recorded. We recorded strain at failure and mode of failure (pullout vs breakage). Eight different sutures were tested: 6-0, 8-0, 9-0, and 10-0 nylon; and 6-0, 7-0, 8-0, and 10-0 polypropylene. Average strain at failure of 9-0 nylon most closely approximated 5% (4.9%). Moreover, 8-0 polypropylene and 10-0 nylon and polypropylene failed with average strains less than 5% and a maximum strain of failure less than 8%. Regardless of type, 6-0 to 8-0 caliber suture failed primarily by pullout of the suture from the epineurium whereas 9-0 and 10-0 nylon and polypropylene failed by suture breakage. Decreased precision through increased variability was seen when testing sutures failing via pullout. Nylon suture size 8-0 has been advocated as the suggested intraoperative aid to test strain at nerve repair sites. Our study suggests that 9-0 nylon may be a more appropriate testing suture because of its more predictable failure via breakage and its failure by a threshold of 5% to 8% strain. Although 8-0 nylon and polypropylene may also represent reasonable testing sutures, 8-0 nylon failed on average above 5% strain, with strains exceeding 8%, and both failed via the mechanism of pullout. This study's findings provide information for surgeons attempting to decide during surgery whether to perform direct nerve repair.

Treatment of Mandibular Ameloblastoma Involving the Mandibular Condyle: Resection and Concomitant Reconstruction With a Custom Hybrid Total Joint Prosthesis and Iliac Bone Graft.

To describe the treatment of ameloblastoma involving the mandibular body and condyle in 3 patients. This report describes 3 patients with large ameloblastomas (2 were second recurrences) treated by partial mandibular resection. Involvement of the mandibular condyle in these 3 patients made the reconstruction more challenging. Reconstruction included immediate temporomandibular joint replacement by a custom-made alloplastic total joint and mandibular body (Zimmer-Biomet, Jacksonville, FL). These devices were designed using virtual surgical planning software. The 3 patients underwent concomitant bone graft reconstruction using autogenous-free corticocancellous block bone grafts from the iliac crest. This facilitated later dental implant placement and full dental rehabilitation. Direct inferior alveolar nerve repair or nerve graft reconstruction with allograft was also carried out for all 3 patients. Maxillomandibular fixation was not used in all 3 patients. All the 3 patients underwent successful surgery and recovery. Mandibular function was preserved. The concomitant bone graft allowed successful dental implant placement for subsequent planned restorative dentistry. Ameloblastoma involving the mandibular condyle can be successfully treated by resection and concomitant total joint replacement with an alloplastic device. This technique shows promise in that there is rapid return to excellent function thanks to rigid fixation of the construct. Mirroring software used in the prosthesis design facilitates excellent cosmetic outcomes.

Common Peroneal Nerve Grafting to Repair the Tibial Nerve as a Salvage Procedure in the Treatment of Sciatic Nerve Injury with Long-Segment Defects

Background In sciatic nerve neuropathies, when direct nerve repair is impossible due to a large gap, nerve grafting can be performed. However, the diameters of traditional autologous nerve grafts are too small to cover the whole cross-sectional area of the sciatic nerve. The aim of this study is to present the outcome of common peroneal nerve grafting to repair the tibial nerve in eight patients with sciatic nerve injuries, showing long defects of more than 10 cm. Methods Between 2007 and 2013, the common peroneal nerve was used as an autograft to repair the tibial nerve in eight patients with complete high sciatic nerve injury with long defects. There were 6 men and 2 women with an average age of 31 years (range: 17–44 years). Muscle strength was evaluated using the British Medical Research Council scale. The Semmes–Weinstein monofilament test was used for sensory evaluation. Results The follow-up time for patients ranged from 36 to 60 months, with an average of 48.75 months. Tibial nerve motor function was “good” or “very good” (M3–M4) in five out of eight patients (55.6%). Plantar flexion was not adequate in the rest of the patients. Sensory recovery was “good” or “very good” (S2–S3) in six patients and “inadequate” (S4) in two patients. Conclusion In cases where there were extensive gaps in the sciatic nerve, using the common peroneal nerve as an autograft to repair the tibial nerve provides an alternative to traditional nerve graft repair.

Results of Distal Nerve Transfers in Restoration of Shoulder Function in C5 and C6 Root Avulsion Injury to the Brachial Plexus

Background The lack of shoulder function following brachial plexus injury is a debilitating condition. Nerve root avulsion injury precludes a direct nerve repair. Under these circumstances, distal nerve transfer is a well-established technique in the restoration of shoulder abduction and external rotation. Methods Thirty patients with C5 and C6 root avulsion injury were treated with distal nerve transfers in the period between February 2009 and December 2012.The average denervation period was 5.6 months. Shoulder function was restored by posterior transfer of distal part of the spinal accessory nerve into the suprascapular nerve and transfer of the long head triceps branch of radial nerve to the anterior branch of axillary nerve. An additional nerve transfer was performed in four patients with winged scapula by transferring a part of thoracodorsal nerve into the long thoracic nerve. Results Twenty-seven patients recovered shoulder abduction; 18 scored M4 and 9 scored M3. Range of abduction averaged 118 degrees (range, 90–170 degrees). Nineteen patients restored external rotation with an average of 53 degrees (range: 30–70 degrees). Three patients failed to recover shoulder abduction though the joint regained stability. External rotation remained severely restricted in 11 patients. At final follow-up, winging of scapula improved in three of four patients following reinnervation of the serratus anterior muscle. Conclusion Nerve transfers, when performed close to the target muscles, restore good range and strength of shoulder abduction in most patients with C5 and C6 root avulsion injuries. However, return in external rotation is not as good as the recovery in abduction.

The Present and Future for Peripheral Nerve Regeneration.

Peripheral nerve injury can have a potentially devastating impact on a patient's quality of life, resulting in severe disability with substantial social and personal cost. Refined microsurgical techniques, advances in peripheral nerve topography, and a better understanding of the pathophysiology and molecular basis of nerve injury have all led to a decisive leap forward in the field of translational neurophysiology. Nerve repair, nerve grafting, and nerve transfers have improved significantly with consistently better functional outcomes. Direct nerve repair with epineural microsutures is still the surgical treatment of choice when a tension-free coaptation in a well-vascularized bed can be achieved. In the presence of a significant gap (>2-3 cm) between the proximal and distal nerve stumps, primary end-to-end nerve repair often is not possible; in these cases, nerve grafting is the treatment of choice. Indications for nerve transfer include brachial plexus injuries, especially avulsion type, with long distance from target motor end plates, delayed presentation, segmental loss of nerve function, and broad zone of injury with dense scarring. Current experimental research in peripheral nerve regeneration aims to accelerate the process of regeneration using pharmacologic agents, bioengineering of sophisticated nerve conduits, pluripotent stem cells, and gene therapy. Several small molecules, peptides, hormones, neurotoxins, and growth factors have been studied to improve and accelerate nerve repair and regeneration by reducing neuronal death and promoting axonal outgrowth. Targeting specific steps in molecular pathways also allows for purposeful pharmacologic intervention, potentially leading to a better functional recovery after nerve injury. This article summarizes the principles of nerve repair and the current concepts of peripheral nerve regeneration research, as well as future perspectives. [Orthopedics. 2017; 40(1):e141-e156.].

Transferência de nervos (neurotizações) no tratamento das lesões traumáticas do plexo braquial

Brachial plexus avulsion injuries are usually caused by car and motorcycle accidents. Their consequences are devastating and represent a challenge to the surgeons who assist these patients. Positive results of this procedure depend on the interval between the injury and the definitive treatment. The treatment of brachial plexus avulsion injuries invariably involves the use of neurolysis, direct nerve repair, nerve grafts, and neurotization procedures. Several nerves have been used as donors in neurotizations. In general, there are two types of donor: extraplexal (intercostal, spinal accessory, and phrenic nerves, motor branches of the cervical plexus, and contralateral C7 root) and intraplexal (proximal spinal nerve stumps or collateral motor branches of the preserved brachial plexus). In fact, the intraplexal neurotization represents the classical form of nerve transfers.

Patient outcome after surgical management of the spinal accessory nerve injury: A long-term follow-up study.

Objectives:A lesion in the spinal accessory nerve is typically iatrogenic: related to lymph node biopsy or excision. This injury may cause paralysis of the trapezius muscle and thus result in a characteristic group of symptoms and signs, including depression and winging of the scapula, drooped shoulder, reduced shoulder abduction, and pain. The elements evaluated in this long-term follow-up study include range of shoulder motion, pain, patients’ satisfaction, delay of surgery, surgical procedure, occupational status, functional outcome, and other clinical findings.Methods:We reviewed the medical records of a consecutive 37 patients (11 men and 26 women) having surgery to correct spinal accessory nerve injury. Neurolysis was the procedure in 24 cases, direct nerve repair for 9 patients, and nerve grafting for 4. Time elapsed between the injury and the surgical operation ranged from 2 to 120 months. The patients were interviewed and clinically examined after an average of 10.2 years postoperatively.Results:The mean active range of movement of the shoulder improved at abduction 44° (43%) in neurolysis, 59° (71%) in direct nerve repair, and 30° (22%) in nerve-grafting patients. No or only slight atrophy of the trapezius muscle was observable in 75%, 44%, and 50%, and no or controllable pain was observable in 63%, 56%, and 50%. Restriction of shoulder abduction preceded deterioration of shoulder flexion. Patients’ overall dissatisfaction with the state of their upper extremity was associated with pain, lower strength in shoulder movements, and occupational problems.Conclusion:We recommend avoiding unnecessary delay in the exploration of the spinal accessory nerve, if a neural lesion is suspected.

Ulnar Nerve Repair With Simultaneous Metacarpophalangeal Joint Capsulorrhaphy and Pulley Advancement

To evaluate the validity of performing a static anti-claw procedure (metacarpophalangeal joint volar capsulorrhaphy and A1 and A2 pulley release) at the time of ulnar nerve repair for acute or chronic lacerations to prevent development of claw hand deformity and disability or to correct them. We present a case series of 14 patients for whom metacarpophalangeal joint capsulorrhaphy and pulley advancement were done at the time of ulnar nerve management. Direct nerve repair was performed in 10 patients, nerve grafting in 2, neurolysis in 1, and combined direct repair and anterior interosseous nerve transfer in 1. Outcome measurements included assessment of claw hand correction and sequence of phalangeal flexion according to modified evaluation criteria of Brand and motor recovery of ulnar nerve function using the British Medical Research Council (MRC) scale. Average follow-up was 39 months. At 3 months, 12 patients had good and 2 had fair claw hand correction. At 6 months, 2 patients had excellent, 10 patients had good, and 2 patients had fair correction. At final follow-up, 13 patients had good to excellent correction and 1 had fair correction. Motor recovery of the intrinsic muscles was rated from 2 to 5 according to the MRC scale. This technique is simple and effective. It acts as an internal orthosis during recovery of sufficient strength of the intrinsic muscles. In cases of incomplete recovery of the intrinsic muscles (up to MRC grade 2), it may eliminate the need for secondary surgery to correct a claw hand deformity. Therapeutic IV.

Histoire de la paralysie faciale

Facial paralysis has been a recognized condition since Antiquity, and was mentionned by Hippocratus. In the 17th century, in 1687, the Dutch physician Stalpart Van der Wiel rendered a detailed observation. It was, however, Charles Bell who, in 1821, provided the description that specified the role of the facial nerve. Facial nerve surgery began at the end of the 19th century. Three different techniques were used successively: nerve anastomosis, (XI-VII Balance 1895, XII-VII, Korte 1903), myoplasties (Lexer 1908), and suspensions (Stein 1913). Bunnell successfully accomplished the first direct facial nerve repair in the temporal bone, in 1927, and in 1932Balance and Duel experimented with nerve grafts. Thanks to progress in microsurgical techniques, the first faciofacial anastomosis was realized in 1970 (Smith, Scaramella), and an account of the first microneurovascular muscle transfer published in 1976by Harii. Treatment of the eyelid paralysis was at the origin of numerous operations beginning in the 1960s; including palpebral spring (Morel Fatio 1962) silicone sling (Arion 1972), upperlid loading with gold plate (Illig 1968), magnets (Muhlbauer 1973) and transfacial nerve grafts (Anderl 1973). By the end of the 20th century, surgeons had at their disposal a wide range of valid techniques for facial nerve surgery, including modernized versions of older techniques.

Single-stage Dynamic Reanimation of the Smile in Irreversible Facial Paralysis by Free Functional Muscle Transfer

Unilateral facial paralysis is a common disease that is associated with significant functional, aesthetic and psychological issues. Though idiopathic facial paralysis (Bell’s palsy) is the most common diagnosis, patients can also present with a history of physical trauma, infectious disease, tumor, or iatrogenic facial paralysis. Early repair within one year of injury can be achieved by direct nerve repair, cross-face nerve grafting or regional nerve transfer. It is due to muscle atrophy that in long lasting facial paralysis complex reconstructive methods have to be applied. Instead of one single procedure, different surgical approaches have to be considered to alleviate the various components of the paralysis. The reconstruction of a spontaneous dynamic smile with a symmetric resting tone is a crucial factor to overcome the functional deficits and the social handicap that are associated with facial paralysis. Although numerous surgical techniques have been described, a two-stage approach with an initial cross-facial nerve grafting followed by a free functional muscle transfer is most frequently applied. In selected patients however, a single-stage reconstruction using the motor nerve to the masseter as donor nerve is superior to a two-stage repair. The gracilis muscle is most commonly used for reconstruction, as it presents with a constant anatomy, a simple dissection and minimal donor site morbidity. Here we demonstrate the pre-operative work-up, the post-operative management, and precisely describe the surgical procedure of single-stage microsurgical reconstruction of the smile by free functional gracilis muscle transfer in a step by step protocol. We further illustrate common pitfalls and provide useful tips which should enable the reader to truly comprehend the procedure. We further discuss indications and limitations of the technique and demonstrate representative results.

Skin derived precursor Schwann cells improve behavioral recovery for acute and delayed nerve repair

Previous work has shown that infusion of skin-derived precursors pre-differentiated into Schwann cells (SKP-SCs) can remyelinate injured and regenerating axons, and improve indices of axonal regeneration and electrophysiological parameters in rodents. We hypothesized that SKP-SC therapy would improve behavioral outcomes following nerve injury repair and tested this in a pre-clinical trial in 90 rats. A model of sciatic nerve injury and acellular graft repair was used to compare injected SKP-SCs to nerve-derived Schwann cells or media, and each was compared to the gold standard nerve isograft repair. In a second experiment, rats underwent right tibial nerve transection and received either acute or delayed direct nerve repair, with injections of either 1) SKP-SCs distal to the repair site, 2) carrier medium alone, or 3) dead SKP-SCs, and were followed for 4, 8 or 17weeks. For delayed repairs, both transected nerve ends were capped and repaired 11weeks later, along with injections of cells or media as above, and followed for 9 additional weeks (total of 20weeks). Rats were serially tested for skilled locomotion and a slip ratio was calculated for the horizontal ladder-rung and tapered beam tasks. Immediately after nerve injury and with chronic denervation, slip ratios were dramatically elevated. In the GRAFT repair study, the SKP-SC treated rats showed statistically significant improvement in ladder rung as compared to all other groups, and exhibited the greatest similarity to the sham controls on the tapered beam by study termination. In the ACUTE repair arm, the SKP-SC group showed marked improvement in ladder rung slip ratio as early as 5weeks after surgery, which was sustained for the duration of the experiment. Groups that received media and dead SKP-SCs improved with significantly slower progression. In the DELAYED repair arm, the SKP-SC group became significantly better than other groups 7weeks after the repair, while the media and the dead SKP-SCs showed no significant improvement in slip ratios. On histomorphometrical analysis, SKP-SC group showed significantly increased mean axon counts while the percent myelin debris was significantly lower at both 4 and 8weeks, suggesting that a less inhibitory micro-environment may have contributed to accelerated axonal regeneration. For delayed repair, mean axon counts were significantly higher in the SKP-SC group. Compound action potential amplitudes and muscle weights were also improved by cell therapy. In conclusion, SKP-SC therapy improves behavioral recovery after acute, chronic and nerve graft repair beyond the current standard of microsurgical nerve repair.

Advances in nerve repair and reconstruction

Despite advances in microsurgical techniques, peripheral nerve injury poses an ongoing challenge to treating surgeons. While choosing the appropriate surgical approach and using precise technique are important in obtaining optimal outcomes, current research in nerve repair focuses on using knowledge of biologic nerve regeneration to develop new strategies in peripheral nerve repair. In the following review article, the relevant anatomy and physiology involved in the regeneration of injured nerves are described. Both traditional and innovative strategies in nerve repair are discussed as well as their applicability to various nerve injuries. While the anatomy and physiology of nerves predicate their susceptibility to mechanical and ischemic injury, the specific type of injury dictates the optimal treatment algorithm. In particular, peripheral nerve injuries associated with significant gaps between damaged nerve endings provide a challenge for hand surgeons, and a variety of solutions to this problem will be discussed. Direct nerve repair continues to be the gold standard treatment for nerve lacerations. For nerve injuries that do not allow for a direct repair, alternative management options include autografts, allografts, and biologic or synthetic conduits. Recent research in neurotrophic factors present potentially groundbreaking biologic possibilities to help guide nerve regeneration after repair.

Harvey Cushing’s Surgical Treatment of Facial Paralysis During His Tenure at the Johns Hopkins Hospital

Results Twelve patients underwent surgical treatment for facial nerve disorders. The mean age was 29 years (range 14 to 52); most were male (80%). Seven had facial nerve disorders of iatrogenic etiology; two were secondary to trauma; two were idiopathic, and one patient was treated for idiopathic facial motor spasms. Two patients underwent direct facial nerve repair; four underwent spino-facial coaptation with complete division of the spinal accessory nerve; four underwent spino-facial coaptation with partial division of the spinal accessory nerve, and in one the attempt at coaptation was abandoned due to difficulties in the operative approach. Eight had long -term follow-up. Mean length of follow-up was 47.6 months (range 2.9 to 285.4). At the time of discharge from the hospital 11 patients were listed as “improved” or “well;” the patient in whom nerve coaptation was abandoned was “unimproved” At the last follow-up, six patients were improved; one was unimproved, and one experienced new-onset facial spasms which required resection of the nerve coaptation. Conclusions We report here ten spino-facial and two primary repairs that Cushing performed from 1902 to 1911, eleven of which were previously undescribed. These cases provided Cushing with insight into the management of these conditions, and in 1910 he stated that “the most satisfactory function results naturally follow an anastomosis made immediately after facial transection.” Many of the principles described by Cushing in the early twentieth century still hold true today.

Timing for repair in brachial plexus injury

BackgroundBrachial plexus injuries predominantly target young individuals and result in severe functional impairment in the affected limb. Management of these injuries is challenging and functional gains are often unpredictable. Though there is a general agreement that early repairs result in better functional outcomes, a period of observation, sometimes, will allow a good spontaneous recovery in traction related injuries. Mode of injury will also have a bearing while deciding the timing of repair. MethodsIf attempted immediate, direct repair of plexal elements is feasible in clean transections. In late repairs, nerve ends retract and require nerve grafting. Missile injuries and traction induced injuries are observed for spontaneous recovery for a period of up to 3 months. Presence of pseudomeningoceles in MR myelography is an indication for an early surgery. Neurolysis, direct nerve repair, nerve grafting, nerve transfer, pedicle muscle transfer and functioning free-muscle transfer are the main surgical procedures in the management of brachial plexus injuries. ResultsGood results are expected following immediate and direct repair of clean transections in upper plexal elements. Early repairs give better results than delayed repairs in all kinds of brachial plexus lesions. ConclusionThe timing of repair in brachial plexus injury is dependent on several factors, e.g; the mechanism of injury, type of injury, speed of the vehicle, and the mode of fall while victim lands on the ground. High speed motor cycle accidents usually result in root avulsions and demand an early intervention. Clean transections should be repaired immediately, whereas missile and traction induced injuries should be observed for spontaneous recovery for a period up to 3 months.

Facial reanimation after nerve sacrifice in the treatment of head and neck cancer

This article reviews literature on the facial reanimation technique, from direct facial nerve repair and grafting to neuromuscular-free transplantation. The discussion will focus on the indications of the different approaches based on timing of the facial palsy and on patient's features. Facial nerve coaptation technique with masseteric nerve, babysitter procedures, and neuromuscular transplantation represent today the gold standard for facial reanimation after facial nerve sacrifice. Surgeon's experience and patient selection have to be considered as other important factors for surgical approach selection. Facial animation represents a difficult challenge for the reconstructive surgeon. A large number of surgical techniques and modifications have been published, and the appropriate approach must be selected based on the kind of facial palsy, its timing, and the patient's age, prognosis, and general condition. A complete grasp of all the approaches that allows for a target surgery represents today an essential assumption for the facial reanimation.

Mesh epineurial splinting for late median nerve repair in older patients: A preliminary report

Eleven patients over 40 years old, with median nerve lesions at the wrist, were operated on an average of 5 months after their injury. In six patients, the median nerve was repaired using a polypropylene mesh applied to secure the nerve stumps in contact, thereby allowing for direct repair with microsutures. Six patients had their median nerve repaired with sural grafts. The average gap length was 2.8 cm for the mesh repair, whereas it was 3.7 cm for the graft repair group. Eighteen months after surgery, pressure thresholds were perceived in the index and thumb pulp by all six patients with a mesh repair but in only two of five patients with a graft repair. Five in the mesh repair group recovered function in the abductor pollicis brevis muscle, versus none in the graft group. These preliminary results suggest that, in older patients, the use of a mesh to splint the coaptation site followed by direct nerve repair yields better recovery than conventional sural grafts.

Cortical representation sites of mimic movements after facial nerve reconstruction: A functional magnetic resonance imaging study

To describe cortical reorganization after classic hypoglossal-facial nerve anastomosis (HFA) (four patients), hypoglossal-facial nerve jump anastomosis (HFJA) (three patients), and facial nerve interpositional graft (FNIG) (three patients). Prospective case series. Functional magnetic resonance imaging (fMRI) was performed during lip and tongue movement using a block or an event-related design. Despite the presence of some intersubject variability, the following general brain activation patterns were revealed: As expected, lip movements after FNIG led to selective brain activation in the original facial motor cortex, and lip movements after HFA were associated with activation in the hypoglossal motor cortex. Following HFJA, lip movements resulted in overlapping activation encompassing both the original facial and the hypoglossal motor cortex, but tongue movements led solely to strong activation within the original hypoglossal motor cortex. In contrast, tongue movements after HFA were associated with strong activation in the original hypoglossal motor cortex and weaker activation in the facial motor cortex. Direct facial nerve repair (FNIG) leads to restoration of the original cortical activation. A cross nerve suture (HFA or HFJA) changes cortical activation and leads to different patterns of cortical activation during lip and tongue movements.

Pain and brachial plexus lesions: evaluation of initial outcomes after reconstructive microsurgery and validation of a new pain severity scale

Peripheral nerve lesions usually are associated with neuropathic pain. In the present paper, we describe a simple scale to quantify pain after brachial plexus injuries and apply this scale to a series of patients to determine initial outcomes after reconstructive surgery. Fifty-one patients with traumatic brachial plexus avulsion injuries were treated over the period of one calendar year at one center by the same surgical team. Of these, 28 patients who were available for follow-up reported some degree of neuropathic pain radiating towards the hand or forearm and underwent reconstructive microsurgery and direct pain management, including trunk and nerve neurolysis and repair. A special pain severity rating scale was developed and used to assess patients' pain before and after surgery, over a minimum follow-up of 6 months. An independent researcher, not part of the surgical team, performed all pre- and postoperative evaluations. Of the 28 patients with brachial plexus traction injuries who met eligibility criteria, 93% were male, and most were young (mean age, 27.6 years). The mean preoperative severity of pain using our scale was 30.9 out of a maximum of 37 (± 0.76 SD), which fell to a mean of 6.9 (± 0.68 SD) 6 months post-procedure. On average, pain declined by 78% across the whole series, a decline that was statistically significant (p < .001). Subset analysis revealed similar improvements across all the different parameters of pain. We have designed and tested a simple and reliable method by which to quantify neuropathic pain after traumatic brachial plexus injuries. Initial surgical treatment of the paralysis--including nerve, trunk and root reconstruction, and neurolysis--comprises an effective means by which to initially treat neuropathic pain. Ablative or neuromodulative procedures, like dorsal root entry zone, should be reserved for refractory cases.

Behavioural and anatomical analysis of selective tibial nerve branch transfer to the deep peroneal nerve in the rat

Nerve transfer procedures involving the repair of a distal denervated nerve element with that of a foreign proximal nerve have become increasingly popular for clinical nerve repair as a surgical alternative to autologous nerve grafting. However, the functional outcomes and the central plasticity for these procedures remain poorly defined, particularly for a clinically relevant rodent model of hindlimb nerve transfer. We therefore evaluated the effect of selective tibial branch nerve transfer on behavioural recovery in animals following acute transection of the deep peroneal nerve. The results indicate that not only can hindlimb nerve transfers be successfully accomplished in a rat model but that these animals display a return of skilled locomotor function on a par with animals that underwent direct deep peroneal nerve repair (the current gold standard). At 2 months, ground reaction force analysis demonstrated that partial restoration of braking forces occurred in the nerve transfer group, whereas the direct repair group had fully restored these forces to similar to baseline levels. Ankle kinematic analysis revealed that only animals in the direct repair group significantly recovered flexion during the step cycle, indicating a recovery of surgically induced foot drop. Terminal electrophysiological and myological assessments demonstrated similar levels of reinnervation, whereas retrograde labelling studies confirmed that the peroneal nerve-innervated muscles were innervated by neurons from the tibial nerve pool in the nerve transfer group. Our results demonstrate a task-dependent recovery process, where skilled locomotor recovery is similar between nerve transfer and direct repair animals, whereas flat surface locomotion is significantly better in direct repair animals.