Heterotopic nerve transfers: recent trends with expanding indication

Management of "Long" Nerve Gaps

Long-gap nerve injuries offer unique physiological and logistical treatment challenges to the reconstructive surgeon. Options include nerve autograft, processed nerve allograft, nerve transfers, and tendon transfers. This review provides an evidence-framed discussion regarding the pros and cons of these diverse approaches.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Anatomical Location of the Vesical Branches of the Inferior Hypogastric Plexus in Human Cadavers

We have demonstrated in canines that somatic nerve transfer to vesical branches of the inferior hypogastric plexus (IHP) can be used for bladder reinnervation after spinal root injury. Yet, the complex anatomy of the IHP hinders the clinical application of this repair strategy. Here, using human cadavers, we clarify the spatial relationships of the vesical branches of the IHP and nearby pelvic ganglia, with the ureteral orifice of the bladder. Forty-four pelvic regions were examined in 30 human cadavers. Gross post-mortem and intra-operative approaches (open anterior abdominal, manual laparoscopic, and robot-assisted) were used. Nerve branch distances and diameters were measured after thorough visual inspection and gentle dissection, so as to not distort tissue. The IHP had between 1 to 4 vesical branches (2.33 ± 0.72, mean ± SD) with average diameters of 0.51 ± 0.06 mm. Vesical branches from the IHP arose from a grossly visible pelvic ganglion in 93% of cases (confirmed histologically). The pelvic ganglion was typically located 7.11 ± 6.11 mm posterolateral to the ureteral orifice in 69% of specimens. With this in-depth characterization, vesical branches from the IHP can be safely located both posterolateral to the ureteral orifice and emanating from a more proximal ganglionic enlargement during surgical procedures.

Anatomical Study of Cross-Transfer of the Contralateral C7 Nerve Through the Posterior Epidural Pathway of the Cervical Spine for the Treatment of Spastic Paralysis of the Upper Limbs

BACKGROUND

This study explored the safety and feasibility of surgical treatment of spastic paralysis of the central upper extremity by contralateral cervical 7 nerve transfer via the posterior epidural pathway of the cervical spine.

METHODS

Five fresh head and neck anatomical specimens were employed to simulate contralateral cervical 7 nerve transfer through the posterior epidural pathway of the cervical spine. The relevant anatomical landmarks and surrounding anatomical relationships were observed under a microscope, and the relevant anatomical data were measured and analysed.

RESULTS

The posterior cervical incision revealed the cervical 6 and 7 laminae, and lateral exploration revealed the cervical 7 nerve. The length of the cervical 7 nerve outside the intervertebral foramen was measured to be 6.4 ± 0.5 cm. The cervical 6 and cervical 7 laminae were opened with a milling cutter. The cervical 7 nerve was extracted from the inner mouth of the intervertebral foramen, and its length was 7.8 ± 0.3 cm. The shortest distance of the cervical 7 nerve transfer via the posterior epidural pathway of the cervical spine was 3.3 ± 0.3 cm.

CONCLUSIONS

Cross-transfer surgery of the contralateral cervical 7 nerve via the posterior epidural pathway of the cervical spine can effectively avoid the risk of nerve and blood vessel damage in anterior cervical nerve 7 transfer surgery; the nerve transfer distance is short, and nerve transplantation is not required. This approach may become a safe and effective procedure for the treatment of central upper limb spastic paralysis.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Sensory nerve regeneration and reinnervation in muscle following peripheral nerve injury

Sensory afferent fibers are an important component of motor nerves and compose the majority of axons in many nerves traditionally thought of as "pure" motor nerves. These sensory afferent fibers innervate special sensory end organs in muscle, including muscle spindles that respond to changes in muscle length and Golgi tendons that detect muscle tension. Both play a major role in proprioception, sensorimotor extremity control feedback, and force regulation. After peripheral nerve injury, there is histological and electrophysiological evidence that sensory afferents can reinnervate muscle, including muscle that was not the nerve's original target. Reinnervation can occur after different nerve injury and muscle models, including muscle graft, crush, and transection injuries, and occurs in a nonspecific manner, allowing for cross-innervation to occur. Evidence of cross-innervation includes the following: muscle spindle and Golgi tendon afferent-receptor mismatch, vagal sensory fiber reinnervation of muscle, and cutaneous afferent reinnervation of muscle spindle or Golgi tendons. There are several notable clinical applications of sensory reinnervation and cross-reinnervation of muscle, including restoration of optimal motor control after peripheral nerve repair, flap sensation, sensory protection of denervated muscle, neuroma treatment and prevention, and facilitation of prosthetic sensorimotor control. This review focuses on sensory nerve regeneration and reinnervation in muscle, and the clinical applications of this phenomena. Understanding the physiology and limitations of sensory nerve regeneration and reinnervation in muscle may ultimately facilitate improvement of its clinical applications.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Double Fascicular Nerve Transfer to Musculocutaneous Branches for Restoration of Elbow Flexion in Brachial Plexus Injury

Background

Restriction of elbow flexion significantly limits upper extremity function following brachial plexus injuries. In recent years, the double fascicular nerve transfer procedure utilizing ulnar and median nerve transfer to musculocutaneous branches has shown promising functional outcomes.

Objective

To evaluate restoration of elbow flexion following a double fascicular transfer in patients with brachial plexus injuries and identify predictors of poor outcomes.

Methods

This retrospective review included 10 consecutive patients with brachial plexus injuries involving C5-C6 root avulsions who underwent the double nerve transfer procedure. The mean follow-up was 12 months and the primary outcome was assessment of elbow flexion with the use of the Medical Research Council (MRC) scale.

Results

This procedure achieved elbow flexion of MRC grade M3 or higher in 50% of our cohort. Time interval from injury to surgery showed a statistically significant inverse association with functional recovery (r = -0.73, p = 0.016). Patients who had the surgery within six months of the injury, demonstrated higher MRC grades during the follow-up (p = 0.048). There was no association between elbow flexion recovery and age, body mass index (BMI), gender, hypertension, diabetes or smoking status.

Conclusions

The double fascicular transfer to musculocutaneous may be a safe and effective treatment for restoration of elbow flexion. The procedure is associated with superior functional outcomes when performed within the first six months from the injury.

Correlation of compound muscle action potential generated by donor nerves with the recovery of elbow flexion in Oberlin transfer in brachial plexus injury

Objective:

To study the correlation of compound muscle action potential of donor nerves with the recovery of elbow flexion in Oberlin transfer in brachial plexus injury.

Introduction:

Distal nerve transfer using motor fascicle of ulnar or median nerve to restore elbow flexion is a part of reconstructive surgery after upper brachial plexus injury, first described by Oberlin et al. However, one of the most critical influences on functional outcome is number of functioning motor axons in donor fascicle which is reflected by its compound muscle action potential. We studied whether nerve transfers with donor nerves showing higher amplitudes will yield better reinnervation of muscle and therefore better function as estimated by clinical examination.

Methods:

We prospectively studied 30 cases of upper brachial plexus injury, of which were treated with Oberlin transfer using ulnar or median or both nerves. The prerequisites were no elbow flexion and hand and wrist flexors showing the power of more than Medical research Council MRC Grade 4. Donor nerves selected either ulnar or median having CMAP >4 mv in our electrophysiology laboratory during nerve conduction study. Patients were followed up for 1 year and assessed clinically for restoration of elbow flexion, weight tolerance.

Results:

A total of 30 patients of Oberlin transfer were evaluated for improvement power of biceps and elbow flexion. (MRC) grading was done at 1 year. Twenty-seven patients had a good result (MRC grade ≥3), i.e., 90% of patients. Based on the MRC grades, we categorised the patients into two groups as follows: Group A and Group B. Group A included patients with MRC Grade 4–5 and Group B included Grades 3–3.5. We tried to establish a correlation between CMAP and MRC scores by comparison of MRC grade patients for their pre CMAPs which revealed a statistically significant higher CMAPs between the groups. (Mann–Whitney U-test, P = 0.028). This indicates the association of higher pre-CMAPs with higher MRC grades.

Conclusion:

We conclude that higher the compound muscle action potential of donor nerves, better the recovery of elbow flexion in Oberlin transfer in brachial plexus injury.

Comparative study of phrenic and partial ulnar nerve transfers for elbow flexion after upper brachial plexus avulsion: A retrospective clinical analysis

The widely used nerve transfer sources for elbow flexion in patients with upper brachial plexus avulsion (UBPA) include partial ulnar nerve, phrenic nerve, and intercostal nerves. A retrospective review of 21 patients treated with phrenic and partial ulnar nerve transfers for elbow flexion after UBPA was carried out. In the phrenic nerve transfer group, the phrenic nerve was transferred to the anterolateral bundle of the anterior division of the upper trunk; in the partial ulnar nerve transfer group, one fascicle of the ulnar nerve was transferred to the biceps branch. The British Medical Research Council (MRC) grading system, angle of elbow flexion, electromyography (EMG), and the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire scoring were used to evaluate the recovery of elbow flexion at least 3 years postoperatively. The efficiency of motor function in phrenic nerve transfer group was 82%, whereas it was 80% in partial ulnar nerve transfer group. The outstanding rates of angle of elbow flexion were 64% and 70% in phrenic and partial ulnar nerve transfer groups, respectively. The DASH scores after surgery were significantly lower than those before surgery in the two groups. There was no statistical difference between the two groups in the changes of DASH scores before and after surgery. Both of phrenic and partial ulnar nerve transfers had good prognosis for elbow flexion in patients with UBPA.

Spinal accessory nerve repair using a direct nerve transfer from the upper trunk: results with 2 years follow-up

Spinal accessory nerve grafting requires identification of both nerve stumps in the scar tissue, which is sometimes difficult. We propose a direct nerve transfer using a fascicle from the posterior division of the upper trunk. We retrospectively reviewed 11 patients with trapezius palsy due to an iatrogenic injury of the spinal accessory nerve in nine cases. The mean age was 38 years (range 21-59). Preoperatively, patients showed shoulder weakness and limited range of motion. At a mean follow-up of 25 months, active shoulder abduction improvement averaged 57°. Trapezius muscle strength graded M4 or M5 in 10 cases and M3 in one case. No deltoid or triceps impairment was reported. Scapula kinematics was considered normal in seven patients. This technique gave satisfactory functional results and may be an alternative to spinal accessory nerve grafting for the management of trapezius palsies if direct repair is not feasible.

LEVEL OF EVIDENCE

IV.

Oberlin's Transfer: Long Term Outcomes

BACKGROUND

Brachial plexus injury is very commonly associated with road traffic accidents, and frequently affects young adults, causing significant disability and impact on quality of life. The successful treatment of upper plexus injury with the Oberlin technique to restore elbow flexion with good functional results.

METHODS

We retrieved the records of all patients with upper plexus injury who underwent Oberlin transfer operation between March 2007 and July 2012. Outcomes were assessed using the Medical Research Council (MRC) power grading system for biceps muscle, Disabilities of the Arm, Shoulder and Hand score (DASH) for patient functional outcomes and the Visual Analogue Scale for daily disability (VAS where 0- no restrictions; 10- significant limitations) for overall patient satisfaction. Follow-up was performed for at least 12 months post-operatively.

RESULTS

The average follow up period was 43.6 months. Six cases gained effective elbow flexion, improving to MRC grade 5/5 and four cases improved to MRC grade 4/5 for biceps function. The average DASH score was 27.25. One patient had serious disability with no changes after Oberlin's transfer operation. No permanent impairment of ulnar nerve function was observed. Seven out of 10 patients had begun daily work, with no discomfort and no functional impact on activities of daily living.

CONCLUSIONS

We found The Oberlin transfer is a useful salvage procedure and most effective results are for young patients with short interval between injury and operation.

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

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

LEVEL OF EVIDENCE

IV.

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

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

An evidence-based algorithm for the management of common peroneal nerve injury associated with traumatic knee dislocation

Traumatic knee dislocation is a complex ligamentous injury that may be associated with simultaneous vascular and neurological injury.Although orthopaedic surgeons may consider CPN exploration at the time of ligament reconstruction, there is no standardised approach to the management of this complex and debilitating complication.This review focusses on published evidence of the outcomes of common peroneal nerve (CPN) injuries associated with knee dislocation, and proposes an algorithm for the management. Cite this article: Deepak Samson, Chye Yew Ng, Dominic Power. An evidence-based algorithm for the management of common peroneal nerve injury associated with traumatic knee dislocation. EFORT Open Rev 2016;1:362-367. DOI: 10.1302/2058-5241.160012.

Nerve grafts bridging the thenar branch of the median nerve to the ulnar nerve to enhance nerve recovery: a report of three cases

We report a nerve graft procedure bridging the thenar branch of the median nerve to the ulnar nerve in three patients with ulnar nerve transection and defect at the mid-forearm. Ulnar nerve function was evaluated with electroneurography and quantitative sensory-motor testing before and after surgery, and at a 6-year follow-up. After surgery all patients showed electroneurographic evidence of median nerve innervation of the intrinsic muscles normally innervated by the ulnar nerve. The average strength was Grade 4 in the intrinsic muscles originally supplied by the ulnar nerve at the final follow-up. Our results indicate that the thenar branch of the median nerve may support ulnar nerve regeneration and so help prevent intrinsic muscles from irreversible atrophy, but our report is preliminary. This procedure should be validated by future clinical data, especially those with complete ulnar nerve transection at or above the elbow.

LEVEL OF EVIDENCE

IV.

Direct Coaptation of the Phrenic Nerve With the Posterior Division of the Lower Trunk to Restore Finger and Elbow Extension Function in Patients With Total Brachial Plexus Injuries

BACKGROUND

To overcome the mismatch in nerve sizes in phrenic nerve transfer to the radial nerve for elbow and finger extension reanimation for patients with total brachial plexus injuries (TBPI), a selective neurotization procedure was designed.

OBJECTIVE

To investigate the long-term results of phrenic nerve transfer to the posterior division of the lower trunk with direct coaptation in restoring elbow and finger extension after TBPI.

METHODS

Phrenic nerve was transferred to and directly coapted with the posterior division of the lower trunk in 27 patients with TBPI. Seven patients were <18 years old (adolescent group), and the remaining 20 patients ≥18 years (adult group).

RESULTS

Postoperative mean follow-up period was 54 ± 9 months (range, 48-85 months). The motor function attained M3 or greater in 81.5% of patients for elbow extension and in 48% of patients for finger extension. The percentage of patients who regained M3 or greater muscle power of finger extension in the adolescent group and the adult group was 71.4%, and 40%, respectively. Meanwhile, 85.7% in the adolescent group and 80% in the adult group achieved M3 or greater muscle power of elbow extension. There were no significant differences between the 2 groups. The elbow extension and finger extension were synchronous contractions and did not become independent of respiratory effort.

CONCLUSION

This procedure simultaneously and effectively restores the function of elbow and finger extension in patients after TBPI. However, the patients could not do elbow and finger extension separately.

Effect of Collateral Sprouting on Donor Nerve Function After Nerve Coaptation: A Study of the Brachial Plexus

Background

The aim of the present study was to evaluate the donor nerve from the C7 spinal nerve of the rabbit brachial plexus after a coaptation procedure. Assessment was performed of avulsion of the C5 and C6 spinal nerves treated by coaptation of these nerves to the C7 spinal nerve.

Material/Methods

After nerve injury, fourteen rabbits were treated by end-to-side coaptation (ETS), and fourteen animals were treated by side-to-side coaptation (STS) on the right brachial plexus. Electrophysiological and histomorphometric analyses and the skin pinch test were used to evaluate the outcomes.

Results

There was no statistically significant difference in the G-ratio proximal and distal to the coaptation in the ETS group, but the differences in the axon, myelin sheath and fiber diameters were statistically significant. The comparison of the ETS and STS groups distal to the coaptation with the controls demonstrated statistically significant differences in the fiber, axon, and myelin sheath diameters. With respect to the G-ratio, the ETS group exhibited no significant differences relative to the control, whereas the G-ratio in the STS group and the controls differed significantly. In the electrophysiological study, the ETS and STS groups exhibited major changes in the biceps and subscapularis muscles.

Conclusions

The coaptation procedure affects the histological structure of the nerve donor, but it does not translate into changes in nerve conduction or the sensory function of the limb. The donor nerve lesion in the ETS group is transient and has minimal clinical relevance.

The phrenic nerve as a donor for brachial plexus injuries: is it safe and effective? Case series and literature analysis

BACKGROUND

Controversy exists surrounding the use of the phrenic nerve for transfer in severe brachial plexus injuries. The objectives of this study are: (1) to present the experience of the authors using the phrenic nerve in a single institution; and (2) to thoroughly review the existing literature to date.

METHODS

Adult patients with C5-D1 and C5-C8 lesions and a phrenic nerve transfer were retrospectively included. Patients with follow-up shorter than 18 months were excluded. The MRC muscle strength grading system was used to rate the outcome. Clinical repercussions relating to sectioning of the phrenic nerve were studied. An intense rehabilitation program was started after surgery, and compliance to this program was monitored using a previously described scale. Statistical analysis was performed with the obtained data.

RESULTS

Fifty-one patients were included. The mean time between trauma and surgery was 5.7 months. Three-quarters of the patients had C5-D1, with the remainder C5-C8. Mean post-operative follow-up was 32.5 months A MRC of M4 was achieved in 62.7% patients, M3 21.6%, M2 in 3.9%, and M1 in 11.8%. The only significant differences between the two groups were in graft length (9.8 vs. 15.1 cm, p = 0.01); and in the rehabilitation compliance score (2.86 vs. 2.00, p = 0.01).

CONCLUSIONS

Results of phrenic nerve transfer are predictable and good, especially if the grafts are short and the rehabilitation is adequate. It may adversely affect respiratory function tests, but this rarely correlates clinically. Contraindications to the use of the phrenic nerve exist and should be respected.

Comparative study of phrenic nerve transfers with and without nerve graft for elbow flexion after global brachial plexus injury

BACKGROUND

Nerve transfer is a valuable surgical technique in peripheral nerve reconstruction, especially in brachial plexus injuries. Phrenic nerve transfer for elbow flexion was proved to be one of the optimal procedures in the treatment of brachial plexus injuries in the study of Gu et al.

OBJECTIVE

The aim of this study was to compare phrenic nerve transfers with and without nerve graft for elbow flexion after brachial plexus injury.

METHODS

A retrospective review of 33 patients treated with phrenic nerve transfer for elbow flexion in posttraumatic global root avulsion brachial plexus injury was carried out. All the 33 patients were confirmed to have global root avulsion brachial plexus injury by preoperative and intraoperative electromyography (EMG), physical examination and especially by intraoperative exploration. There were two types of phrenic nerve transfers: type1 - the phrenic nerve to anterolateral bundle of anterior division of upper trunk (14 patients); type 2 - the phrenic nerve via nerve graft to anterolateral bundle of musculocutaneous nerve (19 patients). Motor function and EMG evaluation were performed at least 3 years after surgery.

RESULTS

The efficiency of motor function in type 1 was 86%, while it was 84% in type 2. The two groups were not statistically different in terms of Medical Research Council (MRC) grade (p=1.000) and EMG results (p=1.000). There were seven patients with more than 4 month's delay of surgery, among whom only three patients regained biceps power to M3 strength or above (43%). A total of 26 patients had reconstruction done within 4 months, among whom 25 patients recovered to M3 strength or above (96%). There was a statistically significant difference of motor function between the delay of surgery within 4 months and more than 4 months (p=0.008).

CONCLUSION

Phrenic nerve transfers with and without nerve graft for elbow flexion after brachial plexus injury had no significant difference for biceps reinnervation according to MRC grading and EMG. A delay of the surgery after the 4 months might imply a bad prognosis for the recovery of the function.

Preoperative donor nerve electromyography as a predictor of nerve transfer outcomes

PURPOSE

We hypothesized that health of the donor nerve and corresponding muscle, as assessed by electromyography (EMG), could predict the outcome of nerve transfer surgery.

METHODS

A retrospective review was performed to investigate outcomes of nerve transfers for elbow flexion and shoulder abduction. Motor strength was graded preoperatively and after a minimum 1-year follow-up. Preoperative EMG results were classified as functionally normal or affected based on motor unit recruitment pattern and correlated with follow-up motor strength and range of motion.

RESULTS

Forty nerve transfers were identified: 27 were performed for elbow flexion and 13 for shoulder abduction. Overall, the 29 transfers in the normal EMG cohort showed significantly greater postoperative improvement in motor strength (Medical Research Council grade 0.2-4.1) than the 11 transfers in the affected EMG cohort (grade 0.0-3.0). In the shoulder cohort, normal donor nerves resulted in greater strength (grade 4.0 vs. 2.4) and active motion (83° vs. 25°) compared with affected donor nerves. Double fascicular transfers with 2 normal donor nerves demonstrated improved strength compared with double nerve transfers when 1 donor nerve was affected (grade 4.5 vs. 3.2).

CONCLUSIONS

Our findings demonstrate that a simple EMG classification that describes the quality of donor nerves can predict outcome as measured by postoperative motor strength and range of motion. Preoperative EMG evaluation should be considered a valuable supplementary component of the donor nerve selection process when planning brachial plexus reconstruction.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

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

BACKGROUND

Contralateral C7 nerve transfer to the median nerve has been used in an attempt to restore finger flexion in patients with total brachial plexus avulsion injury. However, the results have not been satisfactory mainly because of the requirement to use a long bridging nerve graft, which causes an extended nerve regeneration process and irreversible muscle atrophy. A new procedure involving contralateral C7 nerve transfer via a modified prespinal route and direct coaptation with the injured lower trunk is presented here.

METHODS

Contralateral C7 nerve transfer via the modified prespinal route and direct coaptation with the injured lower trunk was performed in seventy-five patients with total brachial plexus avulsion injury. Thirty-five required humeral shortening osteotomy (3 to 4.5 cm) in order to accomplish the direct coaptation. The contralateral C7 nerve was also transferred to the musculocutaneous nerve through the bridging medial antebrachial cutaneous nerve arising from the lower trunk in forty-seven of the seventy-five patients. Recovery of finger, wrist, and elbow flexion was evaluated with use of the modified British Medical Research Council muscle grading system.

RESULTS

The mean follow-up period (and standard deviation) was 57 ± 6 months (range, forty-eight to seventy-eight months). Motor function with a grade of M3+ or greater was attained in 60% of the patients for elbow flexion, 64% of the patients for finger flexion, 53% of the patients for thumb flexion, and 72% of the patients for wrist flexion.

CONCLUSIONS

Contralateral C7 nerve transfer via a modified prespinal route and direct coaptation with the injured lower trunk decreases the distance for nerve regeneration in patients with total brachial plexus avulsion injury. There was satisfactory recovery of finger flexion and wrist flexion in this series. In addition, contralateral C7 nerve transfer was successfully used to repair two different target nerves: the lower trunk and the musculocutaneous nerve.

Results of surgical techniques for re-innervation of the triceps as additional procedures for patients with upper root injuries

Patients with injuries restricted to the upper and middle trunks of the brachial plexus may obtain recovery of elbow extension via the lower trunk, which makes it difficult to assess the real effect of interventions to restore the triceps function in such cases. This study aimed to determine the impact of surgical strategies for re-innervation of the triceps in individuals with partial injuries of the brachial plexus. Patients were divided into two groups. Group 1 consisted of 21 participants in whom the surgery included one technique for re-innervation of elbow extension. In this group, six different extra- or intra-plexal donors were targeted to one of the motor branches of the triceps muscle. Group 2 was composed of 24 controls in which the reconstruction did not include any intervention for recovering triceps function. The individuals who underwent intervention for re-innervation of the triceps obtained significantly better outcomes for elbow extension than the controls.

Nerve transfers

Nerve transfers have been performed for many years, but the technique is further developing and gaining increased recognition as a time-tested procedure. The original operations are continually modified to treat a wide variety of peripheral nerve injuries, and yield reliable results. In addition, nerve transfers can be used in conjunction with tendon transfers or nerve grafts in order to best treat a specific patient's set of deficits. This review of nerve transfers briefly discusses the evolution of the technique, general principles, some specific transfers, post-operative rehabilitation, and their place on the reconstructive ladder.

Acute transfer of superficial radial nerve to the medial nerve: case report

Distal nerve transfers have proven to be an important addition to the armamentarium for reconstruction of peripheral nerve injuries. As new nerve transfer procedures are developed, the indications for their uses continue to broaden. We report a case of a 77-year-old male who had a 9-cm-long gap of the median nerve after experiencing an avulsion injury to his right forearm. This was successfully treated by transferring superficial radial nerve to the median nerve at the carpal tunnel level, thus restoring thumb, index, and first web sensation. Our report emphasizes that nerve transfers in the emergency setting may be the treatment of first choice in cases where conventional nerve grafting is known to result in poorer outcomes such as in long nerve gaps or in the elderly patient population.

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.

CT appearance of intercostal nerve neurotisation

A nerve transfer or neurotisation procedure is performed to repair damaged nerves, in particular those of the brachial plexus following an avulsion injury. An intercostal to phrenic nerve transfer to re-innervate the diaphragm in patients with high cervical spine injury has also been reported in the literature. We present the imaging finding in a 65-year-old female who had an intercostal nerve transfer for a damaged phrenic nerve following a resection for a non-small cell lung carcinoma.

Contralateral C7 nerve root transfer to neurotize the upper trunk via a modified prespinal route in repair of brachial plexus avulsion injury

PURPOSE

In this report, we present our experience on the repair of brachial plexus root avulsion injuries with the use of contralateral C7 nerve root transfers with nerve grafting through a modified prespinal route.

METHODS

The outcomes of the contralateral C7 nerve root transfer to neurotize the upper trunk and C5/C6 nerve roots of the total or near total brachial plexus nerve root avulsion injury in a series of 41 patients were evaluated. The contralateral C7 nerve root that was dissected to the distal end of the divisions, along with the sural nerve graft, were placed underneath the anterior scalene and longus colli muscles, and then passed through the retro-esophageal space to neurotize the recipient nerve. The mean length of the dissected contralateral C7 nerve root was 6.5 ± 0.7 cm, and the mean length of sural nerve graft was 6.8 ± 1.9 cm. The suprascapular nerve was neurotized additionally by the phrenic nerve or the terminal motor branch of accessory nerve in some patients.

RESULTS

The mean length of the follow-up was 47.2 ± 14.5 months. The muscle strength was graded M4 or M3 for the biceps muscle in 85.4% of patients, for the deltoid muscle in 82.9% of patients, and for the upper parts of pectoral major in 92.7% of patients. The functional recovery of shoulder abduction in the patients with the additional suprascapular nerve neurotization was remarkably improved.

CONCLUSIONS

The modified prespinal route could significantly reduced the length of nerve graft in the contralateral C7 nerve root transfer to the injured upper trunk in brachial plexus root avulsion injury, and it may improve the functional outcomes, which deserves further investigations.

Use of quantitative intra-operative electrodiagnosis during partial ulnar nerve transfer to restore elbow flexion

The transfer of part of the ulnar nerve to the musculocutaneous nerve, first described by Oberlin, can restore flexion of the elbow following brachial plexus injury. In this study we evaluated the additional benefits and effectiveness of quantitative electrodiagnosis to select a donor fascicle. Eight patients who had undergone transfer of a simple fascicle of the ulnar nerve to the motor branch of the musculocutaneous nerve were evaluated. In two early patients electrodiagnosis had not been used. In the remaining six patients, however, all fascicles of the ulnar nerve were separated and electrodiagnosis was performed after stimulation with a commercially available electromyographic system. In these procedures, recording electrodes were placed in flexor carpi ulnaris and the first dorsal interosseous. A single fascicle in the flexor carpi ulnaris in which a high amplitude had been recorded was selected as a donor and transferred to the musculocutaneous nerve. In the two patients who had not undergone electrodiagnosis, the recovery of biceps proved insufficient for normal use. Conversely, in the six patients in whom quantitative electrodiagnosis was used, elbow flexion recovered to an M4 level.

Quantitative intra-operative electrodiagnosis is an effective method of selecting a favourable donor fascicle during the Oberlin procedure. Moreover, fascicles showing a high-amplitude in reading flexor carpi ulnaris are donor nerves that can restore normal elbow flexion without intrinsic loss.

Complications of intercostal nerve transfer for brachial plexus reconstruction

PURPOSE

Although numerous publications discuss outcomes of intercostal nerve transfer for brachial plexus injury, few publications have addressed factors associated with intercostal nerve viability or the impact perioperative nerve transfer complications have on postoperative nerve function. The purposes of this study were to report the results of perioperative intercostal nerve transfer complications and to determine whether chest wall trauma is associated with damaged or nonviable intercostal nerves.

METHODS

All patients who underwent intercostal nerve transfer as part of a brachial plexus reconstruction procedure as a result of injury were identified. A total of 459 nerves in 153 patients were transferred between 1989 and 2007. Most nerves were transferred for use in biceps innervation, free-functioning gracilis muscle innervation, or a combination of the two. Patient demographics, trauma mechanism, associated injuries, intraoperative nerve viability, and perioperative complications were reviewed.

RESULTS

Complications occurred in 23 of 153 patients. The most common complication was pleural tear during nerve elevation, occurring in 14 of 153 patients. Superficial wound infection occurred in 3 patients, whereas symptomatic pleural effusion, acute respiratory distress syndrome, and seroma formation each occurred in 2 patients. The rate of complications increased with the number of intercostal nerves transferred. Nerves were harvested from previously fractured rib levels in 50 patients. Rib fractures were not associated with an increased risk of overall complications but were associated with an increased risk of lack of nerve viability. In patients with rib fractures, intraoperative nerve stimulation revealed 148 of 161 nerves to be functional; these were subsequently transferred. In patients with preoperative ipsilateral phrenic nerve palsy, the risk of increased complications was marginally significant.

CONCLUSIONS

Brachial plexus reconstruction using intercostal nerves can be challenging, especially if there is antecedent chest wall trauma. Complications were associated with increasing numbers of intercostal nerves transferred. Ipsilateral rib fracture was adversely associated with intercostal nerve viability; it was not significantly associated with complication risk and should not be considered a contraindication to transfer. Preoperative phrenic nerve palsy was marginally associated with the likelihood of complications but not postoperative respiratory dysfunction when associated with intercostal nerve transfer.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Primary and delayed repair and nerve grafting for treatment of cut median and ulnar nerves

Traumatic cutting of peripheral nerves of median and ulnar in forearm and wrist can cause disablating sensory and motor disorders in patients' hands. We conducted the present study to compare the results of three surgical methods for repair of injured median and ulnar nerves. We studied 85 patients aged 12-59 years (average, 34 +/- 18 years) with 105 cut median and ulnar nerves at forearm and wrist presenting to Tabriz Shohada hospital from 1994 to 2003. The patients followed for 2-10 years. Sixty patients (65 nerves) underwent primary repair, 16 (25 nerves) treated with delayed method and 9 (15 nerves) received nerve graft. Success was obtained in all patients underwent primary repair. The excellent results were common in younger patients. Of 65 nerves (60 patients) repaired by primary method, 25 had excellent result. Of 16 patients 25 nerves (16 patients) underwent delayed repair, 7 was unsuccessful. Of 15 nerves (9 patients) underwent delayed repair, 5 was unsuccessful. It is concluded that the recovery following primary repair was faster than other methods. For reaching excellent results in repairing peripheral nerves, it is important to considering all rules needed for repairing cut peripheral nerves, as well as accurate evaluation and correct repair of injured surrounding soft tissue such as tendons and their synovium and injured vessels.

Outcome following spinal accessory to suprascapular (spinoscapular) nerve transfer in infants with brachial plexus birth injuries

The purpose of this study is to evaluate the value of distal spinal accessory nerve (SAN) transfer to the suprascapular nerve (SSN) in children with brachial plexus birth injuries in order to better define the application and outcome of this transfer in these infants. Over a 3-year period, 34 infants with brachial plexus injuries underwent transfer of the SAN to the SSN as part of the primary surgical reconstruction. Twenty-five patients (direct repair, n = 20; interposition graft, n = 5) achieved a minimum follow-up of 24 months. Fourteen children underwent plexus reconstruction with SAN-to-SSN transfer at less than 9 months of age, and 11 underwent surgical reconstruction at the age of 9 months or older. Mean age at the time of nerve transfer was 11.6 months (range, 5-30 months). At latest follow-up, active shoulder external rotation was measured in the arm abducted position and confirmed by review of videos. The Gilbert and Miami shoulder classification scores were utilized to report shoulder-specific functional outcomes. The effects of patient age at the time of nerve transfer and the use of interpositional nerve graft were analyzed. Overall mean active external rotation measured 69.6°; mean Gilbert score was 4.1 and the mean Miami score was 7.1, corresponding to overall good shoulder functional outcomes. Similar clinical and shoulder-specific functional outcomes were obtained in patients undergoing early (<9 months of age, n = 14) and late (>9 months of age, n = 11) SAN-to-SSN transfer and primary plexus reconstruction. Nine patients (27%) were lost to follow-up and are not included in the analysis. Optimum results were achieved following direct transfer (n = 20). Results following the use of an interpositional graft (n = 5) were rated satisfactory. No patient required a secondary shoulder procedure during the study period. There were no postoperative complications. Distal SAN-to-SSN (spinoscapular) nerve transfer is a reliable option for shoulder reinnervation in infants with brachial plexus birth injuries. Direct transfer seems to be the optimum method. The age of the patient does not seem to significantly impact on outcome.

DISTAL MEDIAN TO ULNAR NERVE TRANSFERS TO RESTORE ULNAR MOTOR AND SENSORY FUNCTION WITHIN THE HAND

ULNAR NERVE INJURIES can be severely debilitating and result in weakness of wrist flexion, loss of hand intrinsic function, and ulnar-sided hand anesthesia. When these injuries produce a Sunderland fourth- or fifth-degree injury, surgical intervention is necessary for functional recovery. Traditional methods for restoring hand intrinsic function after ulnar nerve palsy include interposition nerve grafting for timely presentations or tendon transfers for either complex injuries or late presentations. Distal median to ulnar nerve transfer to restore ulnar intrinsic nerve muscle function was first performed in 1991. We continue to find it advantageous for recovery of ulnar intrinsic function in patients with proximal ulnar nerve injuries by significantly reducing denervation time and directing motor fibers into this critical motor distribution. Several case reports have been published discussing the concept behind this approach, but none have outlined the specific steps involved in this operation. As such, this article discusses our operative methodology behind the distal median to ulnar neurotization, which includes a Guyon canal release, identification of donor median and recipient ulnar nerve fascicular anatomy within the forearm, and an operative tutorial on proper technique for neurotization to restore both ulnar motor and sensory function. We present the technical nuances of the following nerve transfers to restore ulnar nerve function within the hand: anterior interosseous nerve to deep motor branch of ulnar nerve, third webspace sensory contribution of median nerve to volar sensory component of ulnar nerve, and end-to-side reinnervation of ulnar dorsal cutaneous to the remaining median sensory trunk.

TRANSFER OF A FASCICLE FROM THE POSTERIOR CORD TO THE SUPRASCAPULAR NERVE AFTER INJURY OF THE UPPER ROOTS OF THE BRACHIAL PLEXUS

OBJECTIVE

A new nerve transfer technique using a healthy fascicle of the posterior cord for suprascapular nerve reconstruction is presented. This technique was used in a patient with posttraumatic brachial plexopathy resulting in upper trunk injury with proximal root stumps that were unavailable for grafting associated with multiple nerve dysfunction.

CLINICAL PRESENTATION

A 45-year-old man sustained a right brachial plexus injury after a bicycle accident. Clinical evaluation and electromyography indicated upper trunk involvement. Trapezius muscle function and triceps strength were normal on physical examination.

INTERVENTION

The patient underwent a combined supra- and infraclavicular approach to the brachial plexus. A neuroma-in-continuity of the upper trunk and fibrotic C5 and C6 roots were identified. Electrical stimulation of the phrenic and spinal accessory nerves produced no response. The suprascapular nerve was dissected from the upper trunk, transected, and rerouted to the infraclavicular fossa. A healthy fascicle of the posterior cord to the triceps muscle was transferred to the suprascapular nerve. At the time of the 1-year follow-up evaluation, arm abduction against gravity and external rotation reached 40 and 34 degrees, respectively.

CONCLUSION

The posterior cord can be used as a source of donor fascicle to the suprascapular nerve after its infraclavicular relocation. This new intraplexal nerve transfer could be applied in patients with isolated injury of the upper trunk and concomitant lesion of the extraplexal nerve donors usually used for reinnervation of the suprascapular nerve.

Nerve transfers for severe nerve injury

Nerve transfers are becoming used increasingly for repair of severe nerve injures, especially brachial plexus injuries, where the proximal spinal nerve roots have been avulsed from the spinal cord. The procedure essentially involves the coaptation of a proximal foreign (donor) nerve to the distal denervated (recipient) nerve, so that the latter's end-organs will be reinnervated by the donated axons. Cortical plasticity appears to play an important physiologic role in the functional recovery of the reinnervated muscles. This article provides the indications for nerve transfer, principles for their use, and a comprehensive survey on various intraplexal and extraplexal nerves that have been used for transfer to repair clinical nerve injuries. Specific transfers to reanimate muscles denervated by the common patterns of brachial plexus are emphasized, including expected clinical outcomes based on the existing literature.

Involuntary, electrically excitable nerve transfer for denervation: results from an animal model

PURPOSE

The purpose of this study was to evaluate the efficacy of "paralyzed" nerve transfer (ie, transfer of an involuntary, nondegenerated, electrically excitable nerve onto an involuntary, degenerated, non-electrically excitable nerve) and functional electrical stimulation for reinnervation. We hypothesized that lower motor neuron cell body continuity with the motor cortex, via intact upper motor neurons, is not necessary for reinnervation of the extremities.

METHODS

Fischer 344 rats had lower thoracic spinal cord injury (SCI) followed by unilateral tibial nerve transection and delayed peroneal ("paralyzed") to tibial nerve transfer (group A) or primary neurorrhaphy (group B). Control groups had SCI and a unilateral hindlimb incision and nerve exposure only (group C) or a unilateral hindlimb disection and transection of both the tibial and peroneal nerves (group D). Three months after surgery, the proximal peroneal (group A) or proximal tibial (groups B, C, and D) nerves were electrically stimulated in vivo, and gastrocnemius force production was measured on both the operative and nonoperative hindlimbs. In addition, the distal tibial nerves from both the experimental and control-side hindlimbs were sectioned and stained with anti-neurofilament protein to determine total axon counts.

RESULTS

Mean gastrocnemius force return and mean axonal regeneration was 47% and 51%, respectively, for group A animals (n = 9), 68% and 73% for group B animals (n = 4), 97% and 99% for group C animals (n = 4), and 0 and 2% for group D animals (n = 4). A 1-way analysis of variance for independent samples yielded significant differences between groups A, B, and C for gastrocnemius force return and between all groups for axonal regeneration.

CONCLUSIONS

Paralyzed nerve transfer produces a mean of approximately 50% return of gastrocnemius force and axonal regeneration. Paralyzed nerve transfer combined with functional electrical stimulation is a viable method for reanimating denervated motor units in the setting of SCI.

Distal nerve transfers: a biology-based rationale

Peripheral nerve injuries can result in devastating numbness and paralysis. Surgical repair strategies have historically focused on restoring the original anatomy with interposition grafts. Distal nerve transfers are becoming a more common strategy in the repair of nerve deficits as these interventions can restore function in months as opposed to more than a year with nerve grafts. The changes that take place over time in the cell body, distal nerve, and target organ after axotomy can compromise the results of traditional graft placement and may at times be better addressed with the use of distal nerve transfers. A carefully devised nerve transfer offers restoration of function with minimal (if any) detectable deficits at the donor site. A new understanding of cortical plasticity along with patient reeducation allow for good return of strength and function after nerve transfer.

Clinical application of sensory protection of denervated muscle

Following proximal peripheral nerve injury, motor recovery is often poor due to prolonged muscle denervation and loss of regenerative potential. The transfer of a sensory nerve to denervated muscle results in improved functional recovery in experimental models. The authors here report the first clinical case of sensory protection. Following a total hip arthroplasty, this patient experienced a complete sciatic nerve palsy with no recovery at 3 months postsurgery and profound denervation confirmed electrodiagnostically. He underwent simultaneous neurolysis of the sciatic nerve and saphenous nerve transfers to the tibialis anterior branch of the peroneal nerve and gastrocnemius branch from the tibial nerve. He noted an early proprioceptive response. Electromyography demonstrated initially selective amelioration of denervation potentials followed by improved motor recovery in sensory protected muscles only. The patient reported clinically significant functional improvements in activities of daily living. The authors hypothesize that the presence of a sensory nerve during muscle denervation can improve functional motor recovery.

Results of grafting the anterior and posterior divisions of the upper trunk in complete palsies of the brachial plexus

PURPOSE

In most complete brachial plexus injuries, at least 1 root still is available for grafting. We report on the results obtained with reconstruction of the brachial plexus using short sural nerve grafts that connect nonavulsed roots to the anterior, posterior, or both divisions of the upper trunk.

METHODS

We prospectively studied 22 young adults with complete brachial plexus palsy who had surgical repair an average of 5 months after trauma. Sural nerve grafts connected the C5 root to the anterior division and the C6 root to the posterior division of the upper trunk. When the C6 root was not available, the posterior division of the upper trunk was repaired by means of a nerve transfer. In all cases except one, the suprascapular nerve was repaired via a nerve transfer. Outcomes were assessed an average of 35 months after surgery, focusing on recovery of muscle strength, categorized using the Medical Research Council scale. We compared the results obtained after a single root graft, either C5 (n = 11) or C6 (n = 1), with those observed after double root grafting (i.e., C5 + C6; n = 9). The single case of 3 roots available for grafting was excluded for this comparative study.

RESULTS

With grafting of the anterior division of the upper trunk, 17 of the 22 patients (n = 15) regained useful pectoralis major and biceps function of at least M3. Grafting the anterior and the posterior divisions of the upper trunk resulted in 18 of the 22 patients (n = 18) recovering shoulder abduction-adduction and either elbow flexion or extension. In only 5 cases (5 of 22 patients), however, was shoulder abduction-adduction achieved with concomitant recovery of both elbow flexion and extension. Grafting the posterior division of the upper trunk did not enhance the recovery of shoulder abduction, but it did restore elbow extension in approximately 6 of the 9 patients. In terms of muscle strength, an average of 2.3 muscles scored M3 or M4 in the single-root group, compared with 3.1 in the C5/C6 group (p < .05). The relative probability of recovering elbow flexion and shoulder adduction did not differ between patients with 1 versus 2 root grafts. The results of nerve transfers to the posterior division and of forearm muscle reinnervation were poor.

CONCLUSIONS

Grafting the divisions of the brachial plexus ensured multiple function reconstruction in 18 of the 22 patients (n = 18). However, only 5 of 22 patients (n = 4) experienced restoration of elbow flexion and extension.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

The spinal root origins and clinical implications of the lower subscapular nerve

The purpose of this study was to define the spinal root origins of the lower subscapular nerve and the amounts of participating nerve fibers from each spinal root and to discuss the clinical implications. Using a method of separating the nerve fascicles that traces the particular nerve fibers at the intrafascicular level, the spinal root origins of the lower subscapular nerve appeared as two types. The first type comprised 76.9% and was composed of the C5, C6, and C7 roots; the second type comprised 23.1% and was composed of the C6 and C7 roots. The number of nerve fibers was 357.2 +/- 139.7 (mean +/- SD) derived from C5, 1070.4 +/- 390.6 from C6, and 500.0 +/- 285.4 from C7. The nerve fascicles comprising the lower subscapular nerve traveled within the partially common fascicles composed of the axillary nerve. Therefore, injury of the lower subscapular nerve may be accompanied by a lesion of the axillary nerve, which generally consists of C5 and C6 roots composing the posterior cord of the brachial plexus.