Functional Free Muscle Transfer for Reconstruction of Traumatic Adult Brachial Plexus Injuries

Traumatic brachial plexus injury is the most common indication for functional free muscle transfer, and elbow flexion recovery is the functional target, followed by shoulder stability and hand reanimation. In this article, we provide a literature review of functional free muscle transfer (FFMT) for adult traumatic brachial plexus injuries and the surgical technical recommendations to achieve the best functional results with FFMT for adult traumatic brachial plexus injuries.

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

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

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.

Pain Sketches to Predict Pain following Primary Targeted Muscle Reinnervation in Amputees

BACKGROUND

Numeric scales are validated methods to report pain outcomes after targeted muscle reinnervation (TMR) but do not include the assessment of qualitative pain components. This study evaluates the application of pain sketches within a cohort of patients undergoing primary TMR and describes differences in pain progression according to early postoperative sketches.

METHODS

This study included 30 patients with major limb amputation and primary TMR. Patients' drawings were categorized into four categories of pain distribution [focal pain (FP), radiating pain (RP), diffuse pain (DP), or no pain (NP)] and interrater reliability was calculated. Second, pain outcomes were analyzed for each category. Pain scores were the primary outcome, and Patient-Reported Outcomes Measurement Information System (PROMIS) instruments were the secondary outcome.

RESULTS

The interrater reliability for the sketch categories was good (overall kappa coefficient of 0.8). The NP category reported a mean decrease in pain of 4.8 points, followed by the DP (2.5 points) and FP categories (2.0 points). The RP category reported a mean increase in pain of 0.5 points. For PROMIS Pain Interference and Pain Intensity, the DP category reported a mean decrease of 7.2 and 6.5 points, respectively, followed by the FP category (5.3 and 3.6 points). The RP category reported a mean increase of 2.0 points in PROMIS Pain Interference and a mean decrease of 1.4 points in PROMIS Pain Intensity. Secondary outcomes for the NP category were not reported.

CONCLUSION

Pain sketches demonstrated reliability in pain morphology assessment and might be an adjunctive tool for pain interpretation in this setting.

Transfer of the palmaris brevis motor branch to the thenar motor branch: A cadaveric preliminary study

OBJECTIVE

High median nerve injuries can lead to poor distal recovery, especially poor functioning of median innervated thenar muscles involved in thumb opposition and palmar abduction. The palmaris brevis (PB) is a small subcutaneous muscle innervated by ulnar nerve. Innervation of the PB is in most of cases provided by the ulnar digital nerve to the little finger. The purpose of this study is to assess the feasibility of transferring the PB motor branch (PBMB) to the median nerve thenar motor branch (TMB), in order to allow for early restoration of thumb palmar abduction and opposition, through a preliminary cadaveric study.

METHODS

Twenty-five cadaver upper limbs were dissected under magnification. The length of the PBMB and TMB, and their origin were recorded. Nerve transfer from PBMB to TMB was conducted, and evaluated on 2 parameters: surgical feasibility, and distance from the coaptation site to the recipient nerve muscle entry point. The PBMB and TMB were harvested, fixated in formalin, then embedded in paraffin. They were sectioned transversely, and stained with a combination of hematoxylin-eosin and Luxol fast blue. Myelinated axons were counted in each specimen and the donor-to-recipient axon ratio was recorded.

RESULTS

The PBMB was constant and originated from the ulnar digital nerve of the little finger in all cases. The transfer from PBMB to TMB was feasible in all cases. Mean myelinated axon counts of PBMB and TMB were 253±142 and 356±198, respectively (p=0.06). The donor-to-recipient axon ratio was 1:1.41. The mean distance from coaptation of the PBMB to the recipient thenar muscles was 23.1±3.0mm.

CONCLUSIONS

Based on our results, PBMB to TMB transfer is feasible. The PBMB has the advantage over other distal nerve transfer donors to be constant and superficial, allowing for an easier harvest. Moreover, this procedure does not sacrifice any intrinsic function of the hand, and the proximity of the PBMB with the carpal tunnel allows for a single incision procedure. Therefore, early restoration of the median innervated thenar muscles may be feasible by the PBMB to TMB transfer in cases of high median nerve lesions.

LEVEL OF EVIDENCE

IV.

[Postoperative effect analysis of different surgical techniques used in facial nerve reconstruction]

Objective:To investigate the factors and efficacy of different surgical techniques used in facial nerve（FN） reconstruction. Methods:A retrospective analysis was conducted on 24 patients who underwent facial nerve reconstruction surgery in our department from January 2016 to January 2021. The duration of total facial nerve paralysis was less than 18 months. The study included 5 surgical techniques, including 6 cases of FN anastomosis（Group A）, 5 cases of FN grafting（sural nerve or great auricular nerve）（Group B）, 5 cases of side-to-end facial-hypoglossal nerve anastomosis（Group C）, 4 cases of side-to-end FN grafting（sural nerve or great auricular nerve） hypoglossal nerve anastomosis（Group D）, and 4 cases of dual nerve reanimation（Group E）. The postoperative follow-up period was ≥1 year. Results:The HB-Ⅲ level of FN function at 1 year after surgery was 83.3%（5/6） in group A, 60.0%（3/5） in group B, 40.0%（2/5） in group C, 25.0%（1/4） in group D, and 50.0%（2/4） in group E. In patients without multiple FN repair, the incidence of synkinesis was 15.0%（3/20）, while no cases of synkinesis were observed in patients with dual nerve reanimation. The patients who underwent hypoglossal-facial side-to-end anastomosis showed no hypoglossal nerve dysfunction. Conclusion:Different FN repair techniques result in varying postoperative FN function recovery, as personalized repair should be managed. Among the various techniques, FN end-to-end anastomosis after FN transposition is recommended as to reduce the number of anastomotic stoma, while hypoglossal-facial side-to-end anastomosis is advocated as to prevent postoperative hypoglossal nerve dysfunction. Additionally, dual nerve repair can effectively improve smile symmetry and reduce synkinesis, which enhances patients' quality.

Experience with ultrasound neurography for postoperative evaluation of targeted muscle reinnervation

Targeted muscle reinnervation (TMR) was originally developed as a means for increasing intuitive prosthesis control, though later found to play a role in phantom limb pain and neuroma prevention. There is a paucity of literature describing the clinical course of patients with poor TMR surgical outcomes and the value of imaging in the postoperative recovery period. This report will illustrate the potential utility of ultrasound neurography to accurately differentiate TMR surgical outcomes in two patients that received upper extremity amputation and subsequent reconstruction with TMR. Ultrasound evaluation of TMR sites in patient 1 confirmed successful reinnervation, evident by nerve fascicle continuity and eventual integration of the transferred nerve into the target muscle. Conversely, the ultrasound of patient 2 showed discontinuity of the nerve fascicles, neuroma formation, and muscle atrophy in all three sites of nerve transfer, suggesting an unsuccessful procedure and poor functional recovery. Ultrasound neurography is uniquely able to capture the longitudinal trajectory of rerouted nerves to confirm continuity and eventual reinnervation into muscle. Therefore, the application of ultrasound in a postoperative setting can correctly identify instances of failed TMR before this information would become available through clinical evaluation. Early identification of poor TMR outcomes may benefit future patients by fostering the discovery of failure mechanisms and aiding in further surgical planning to improve functional outcomes.

Delayed nerve reconstruction for brachial plexus injuries: is the risk worth the reward?

OBJECTIVE

Nerve reconstruction after 6 months of denervation time in brachial plexus injuries (BPIs) can be inconsistent. A dilemma exists when the use of critical donor nerves for nerve transfers may lead to unreliable outcomes that would waste the donor nerve. The purpose of this study was to evaluate the long-term outcomes of elbow and shoulder function in patients with BPIs receiving nerve reconstruction in the delayed setting (i.e., 6-12 months after injury).

METHODS

Data from patients with delayed BPIs who received a nerve transfer (including proximal and distal nerve transfer/grafting) at a tertiary medical center were retrospectively collected from January 1999 to March 2020. Demographics, extent of injury, mechanism of injury, and reconstructive methods were collected. Patients were categorized into two groups: non-pan-plexus BPI (C5-6, C5-7, and C5-8) and pan-plexus BPI (C5-T1). Acceptable outcome was defined as elbow flexion ≥ M3 status or shoulder abduction ≥ 60°.

RESULTS

Sixty-four patients were included in the study. The average time from injury to nerve reconstruction was 236 (range 180-441) days, and the average follow-up time was 66 months. In the non-pan-plexus BPI group (n = 43 patients), 74.4% of patients demonstrated M3 elbow flexion, and 48.8% of patients demonstrated M4 elbow flexion. Double fascicular transfer yielded better results and faster recovery than a single fascicular transfer. In the pan-plexus BPI group (n = 21 patients), 38.1% of patients reached M3 elbow flexion and 23.8% attained M4 elbow flexion. In the non-pan-plexus BPI group, the recovery rate of acceptable shoulder abduction was 53.5%, but only 23.5% of pan-plexus patients with BPI achieved acceptable shoulder abduction.

CONCLUSIONS

Nerve reconstruction can effectively restore functional elbow flexion and acceptable shoulder abduction in non-pan-plexus patients with BPI in the delayed setting. However, neither acceptable elbow flexion nor shoulder abduction could be consistently achieved in pan-plexus BPI. Judicious use of the donor nerves in pan-plexus injuries is required, in addition to preserving a donor nerve for a backup plan such as free-functioning muscle transplantation or tendon transfers.

Social media analysis of pain outcomes following targeted muscle reinnervation

AIM

Targeted muscle reinnervation (TMR) was developed to improve myoelectric prosthesis control for amputees; however, it has become an area of interest in pain modulation. Evidences indicate that this procedure alleviates chronic pain in amputees. The primary objective of this study was to use social media analysis to understand patients' post-operative pain, satisfaction, and recovery time after TMR.

METHODS

Data were collected from one Facebook group via posts and comments referencing TMR. Posts published between January 1, 2020, and March 24, 2023 were analyzed. Data collected included pain prior to surgery, pain in immediate post-op period, and change in pain after surgery.

RESULTS

Forty-three individuals commented on their TMR experience. Among them, 31 had favorable surgical outcomes, 7 felt that the surgery worsened their pain or there was no significant change in their pain levels, and 5 commented during the initial post-operative period. Twenty-four patients described their pain in the immediate post-operative period and all patients said that the post-operative pain was worse than chronic pain. Among the 28 authors who commented on overall reduction in chronic pain, 24 reported that TMR reduced their pain, whereas 4 reported no change or worsened pain.

CONCLUSIONS

The number of patients (24) who reported improvement in chronic pain aligns with the results in current literature suggesting that TMR is a viable treatment option for pain management. With the current medical management of similar conditions, up to 80% of patients remain unsatisfied with pain management. This analysis supports the evidence that TMR is an effective treatment for patients experiencing post-amputation pain.

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

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

[Robot-assisted Microsurgery in Lower Extremity Reconstruction]

BACKGROUND

In recent years, various robotic systems specifically designed for microsurgical tasks have been developed and approved. There is not much evidence for these systems to date. In our study, we examined the use of robot-assisted microsurgery in the reconstruction of the lower extremity.

PATIENTS/MATERIAL AND METHODS

Data was prospectively collected between February and November 2023. The Symani robotic system was used in 42 robot-assisted microsurgical procedures on the lower extremity, and the results were evaluated and documented.

RESULTS

The average age of the patients was 57±18 years. A total of 39 free flap reconstructions (95%), one lymphatic surgical procedure (3%) and two nerve transfers (5%) were performed. In total, 46 anastomoses and coaptations were carried out. This included six arterial end-to-end anastomoses (11%), seven arterial end-to-side anastomoses (13%), 36 venous end-to-end anastomoses (65%), two lymphovenous anastomoses (4%), and five epineural coaptations in the context of nerve transfers (9%). Arterial end-to-end anastomoses took an average of 26±12 minutes, and arterial end-to-side anastomoses took 42±21 minutes. The venous anastomoses took an average of 33±12 minutes. Epineural coaptations took an average of 24±13 minutes. In no procedure was there a need for a conversion to conventional hand suturing. There were two arterial thromboses (5%), one of which was successfully revised to save the flap. One total flap loss occurred, but there were no partial flap losses.

CONCLUSION

Using the Symani robotic system for microsurgical reconstruction of the lower extremity, we were able to demonstrate results that are comparable to conventional microsurgery.

Rehabilitation protocols in neonates undergoing primary nerve surgery for upper brachial plexus palsy: A scoping review

INTRODUCTION

Surgical management is recommended in patients with severe neonatal brachial plexus palsy (NBPP) within the first 6 months of age to regain best possible function. Rehabilitation post-surgery remains relatively unexplored. This is a scoping review that explores, which rehabilitation modalities exist and how they vary for different microsurgical approaches in NBPP.

MATERIALS AND METHODS

A systematic search was conducted to include articles about upper trunk obstetric brachial plexus nerve microsurgery in pediatric patients that made mention of rehabilitation protocols. The aims of rehabilitation modalities varied and were grouped: "passive" movement to prevent joint contracture or stiffness, "active" or task-oriented movement to improve motor function, or "providing initial motor recovery". Surgical approach was described as either exploration of the brachial plexus (EBP) or nerve transfer without root exploration (NTwoRE). Technique was categorized into transfers and non-transfers.

RESULTS

Thirty-six full-text articles were included. Initiation of rehabilitation was 22.26 days post-surgery. Twenty-eight studies were EBP, and six were NTwoRE. Of studies classifiable by aims, nine were "passive", nine were "active", and five were "providing initial motor recovery". Only 27.7% of EBP studies mentioned active therapy, while 75.0% of NTwoRE studies mentioned active therapy. The average age of patients in the EBP procedure category was 7.70 months, and NTwoRE was 17.76 months. Within transfers, the spinal accessory to suprascapular group was more likely to describe an active shoulder exercise therapy, whereas contralateral C7 group was more likely to describe "initial motor recovery", especially through the use of electrostimulation. All articles on electrostimulation recommended 15-20-minute daily treatment.

CONCLUSION

Information on rehabilitation is limited post-nerve surgery in NBPP. However, when mentioned, the aims of these therapies vary with respect to surgical approach and technique. The type of therapy to employ may be a multifaceted decision, involving factors such as patient age, initial deformity, and goals of the care team.

Intercostal nerve transfer in management of biceps and triceps co-contraction in brachial plexus birth palsy

OBJECTIVE

Brachial plexus birth palsy (BPBP) is often caused by traction during birth. In some cases, reinnervation occurs during spontaneous recovery and it causes involuntary co-contraction between antagonistic muscles. When it comes up between the biceps and triceps muscles, smooth active motion of the elbow joint is impaired. We are presenting outcomes of intercostal nerve (ICN) to radial nerve transfer to minimize elbow motion abnormality due to co-contraction.

METHODS

We present five cases (two males and three females) of biceps and triceps co-contraction in BPBP patients treated from 2005 to 2018. The mean age at surgery was 9.36 years (range, 4.8-16.4 years). They were treated by ICNs transfer to motor branch of the radial nerve to the triceps muscle. Preoperative electromyography was done in all cases to confirm biceps and triceps co-contraction and to assess the contractile status of both muscles. A 10-s flexion extension test was done pre and postoperatively to assess the efficacy of our procedure.

RESULTS

The postop course was uneventful. No donor site morbidity or respiratory complications were recorded in any patient. The mean postoperative follow-up period was 83.9 months (range, 53.6-135.5 months). At the final follow-up, elbow flexion was M4 in the Medical Research Council (MRC) grading scale in all five patients and elbow extension was graded M4 or M4- in all five patients. There was significant increase in the 10 s flexion extension test results delineating the effectiveness of the procedure.

CONCLUSIONS

ICNs transfer to motor branch of the radial nerve to the triceps muscle for management of biceps and triceps co-contraction in BPBP is a good option with minimal morbidity and good success rate.

Rehabilitation Following a Triceps Branch to Axillary Motor Nerve Transfer-A Pragmatic Therapy Guide

Peripheral motor nerve transfer surgery is a technique that may be used to restore motor function to paralyzed muscles. Motor nerve transfer involves harvesting an expendable motor nerve branch, and transfer to the motor branch of the denervated target muscle, using microsurgical coaptation. To date, a standardized rehabilitation protocol does not exist. The 6 stages of rehabilitation after motor nerve transfer surgery were outlined by colleagues in the Birmingham Peripheral Nerve Injury service in 2019. This article aims to provide a practical therapy perspective on the rehabilitation stages of motor nerve transfer surgery outlined in that paper, focusing on the radial to axillary nerve transfer. Timeframes for each stage along with exercise prescription and rationale are provided.

Impact of Timing of Targeted Muscle Reinnervation on Pain and Opioid Intake Following Major Limb Amputation

BACKGROUND

Targeted muscle reinnervation (TMR) has been shown to play an important role in managing neuromas. However, the impact of the timing of TMR on pain visual analogue scale (VAS) scores or patient opioid use has not been thoroughly explored. We hypothesized that TMR performed acutely would lead to lower VAS scores and decreased opioid intake.

METHODS

Prospectively collected data from an amputation registry at a single institution were utilized to identify patients who underwent TMR. Acute TMR was defined as TMR performed within 1 month of the major limb amputation. Primary outcomes included VAS pain scores and patient-reported opioid consumption.

RESULTS

In all, 25 patients (26 limbs) were identified in the acute group, and 18 patients (18 limbs) were identified in the delayed group. At intermediate follow-up (between 4 and 8 months postoperatively) and at final follow-up, the average pain VAS score in the delayed TMR group was significantly higher than that in the acute group (5.2 vs. 1.9 at intermediate P = .01 and 6.2 vs. 1.9 at final P = .002). In all, 84% of the amputees overall were not consuming opioid medications at the time of final follow-up (79% acute, 88% delayed, P = .72). There were no statistically significant differences in opioid consumption between the acute and delayed group at intermediate follow-up (P = .35) or at final follow-up (P = .68).

CONCLUSIONS

TMR is an effective procedure to reduce pain following major limb amputation. Patients with TMR performed acutely had significantly lower VAS pain scores at both intermediate and final follow-up than patients with TMR performed in a delayed setting.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic II.

Functional and morphological evaluation of the trapezius muscle after spinal accessory nerve transfer to brachial plexus nerves

INTRODUCTION

The main innervation of the trapezius muscle is provided by the spinal accessory nerve. Several studies describe the contributions of cervical plexus roots to the trapezius muscle innervation, either directly or through connections with the spinal accessory nerve. There is no adequate understanding of how the trapezius muscle is affected after using the spinal accessory nerve in nerve transfer procedures with the usual technique, preserving at least 1 branch for the upper trapezius.

METHODS

We evaluated 20 patients with sequelae of traumatic brachial plexus injury who underwent surgical procedures for brachial plexus repair or free muscle transfer, which included the spinal accessory nerve transfer technique and were followed for a minimum of 1 year. The three portions trapezius muscle were evaluated by physical examination, magnetic resonance imaging (analysis of fatty degeneration) and electromyography.

RESULTS

In all evaluation methods, the middle and lower portions of the trapezius muscle showed more significant morphological and/or functional impairment than the upper portion, in most cases. There was a statistically significant difference in all the complementary exams results, between the affected side (with sacrifice of the nerve) versus the normal side, in the middle and lower portions of the trapezius muscle.

CONCLUSIONS

Physical examination alone is not sufficient to determine the residual functionality of the trapezius muscle. Magnetic resonance imaging and electromyography are useful tools to assess both morphological involvement of the trapezius muscle and nerve conduction impairment of the trapezius muscle, respectively. The results suggest that the middle and lower portions of the trapezius muscle are affected by previous SAN transfer and should be considered with caution for further muscle transfer procedures.

The Evolution of the Reconstructive Strategy for Elbow Flexion for Acute C5, C6 Brachial Plexus Injuries over Two Decades

BACKGROUND

 Over the course of the past two decades, improved outcomes following brachial plexus reconstruction have been attributed to newer nerve transfer techniques. However, key factors aside from surgical techniques have brought improved consistency to elbow flexion techniques in the latter decade.

METHODS

 One-hundred seventeen patients who underwent brachial plexus reconstruction from 1996 to 2006 were compared with 120 patients from 2007 to 2017. All patients were evaluated preoperatively and postoperatively to assess the recovery time and of elbow flexion strength.

RESULTS

 In the first decade, nerve reconstruction methods included proximal nerve grafting, intercostal nerve transfer, and Oberlin-I transfer. In the second decade, newer methods such as double fascicular transfer and ipsilateral C7 division transfer to the anterior division of upper trunk were introduced. About 78.6% of the first decade group versus 87.5% of the second decade group were able to reach M3 flexion strength (p = 0.04), with shorter time recovery to reach M3 in the 2nd decade. About 59.8% of the first decade group versus 65.0% of the second decade group were able to reach M4 (p = 0.28), but no significant difference in time of recovery. In both groups, the double fascicular nerve transfer had the highest impact when introduced in the second decade. More precise magnetic resonance imaging (MRI) techniques helped to diagnose the level of injury, the roots involved and evaluate the health of the donor nerves in preparation for intraplexus transfer.

CONCLUSION

 In addition to modified techniques in nerve transfers, (1) MRI-assisted evaluation and surgical exploration of the roots with (2) more judicious choice of donor nerves for primary nerve transfer were factors that ensured reliable and outcomes in the second decade.

[Nerve Transfers in Peripheral Nerve Lesions]

BACKGROUND

Lesions of peripheral nerves of the upper extremities often lead to persistent, serious limitations in motor function and sensory perception. Affected patients suffer from both private and professional restrictions associated with long-term physical, psychological and socioeconomic consequences.

INDICATION

An early indication for a nerve transfer shortens the reinnervation distance and improves the growing of motor and sensory axons into the target organ to facilitate early mobility and sensitivity. When planning the timepoint of the surgical procedure, the distance to be covered by reinnervation as well as the morbidities of donor nerves must be considered individually.

RESULTS

Nerve transfers can achieve earlier and safer reinnervation to improve motor and sensory functions after nerve injuries in the upper extremity.

Targeted muscle reinnervation: A narrative review of a novel tool for the management of neuropathic pathology in major lower extremity amputations

OBJECTIVE

The purpose of this narrative review is to provide the vascular surgery community with updated recommendations and information regarding the use of Targeted Muscle Reinnervation (TMR) for both the prevention and treatment of chronic pain and phantom limb pain occurring in patients after undergoing lower extremity amputation for peripheral artery disease.

METHODS

Current available literature discussing TMR is reviewed and included in the article in order to provide a succinct overview on the indications, clinical applications, and surgical technique for TMR. Additionally, early studies showing favorable long-term results after TMR are discussed. Patient consent for publication was obtained for this investigation.

RESULTS

TMR has been demonstrated to be an effective means of both treating and preventing neuroma-related symptoms including chronic pain and phantom limb pain. It has been proven to be technically feasible, and can help patients to have improved utilization of prostheses for ambulation, which can conceivably lead to a reduction in mortality.

CONCLUSIONS

TMR is an important tool to consider for any patient undergoing lower extremity amputation for a vascular-related indication. A vascular-plastic surgeon dual team approach is an effective means to prevent and reduce neuromas and associated chronic pain in this patient population.

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

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

Brain plasticity in neonatal brachial plexus palsies: quantification and comparison with adults' brachial plexus injuries

PURPOSE

To compare two populations of brachial plexus palsies, one neonatal (NBPP) and the other traumatic (NNBPP) who underwent different nerve transfers, using the plasticity grading scale (PGS) for detecting differences in brain plasticity between both groups.

METHODS

To be included, all patients had to have undergone a nerve transfer as the unique procedure to recover one lost function. The primary outcome was the PGS score. We also assessed patient compliance to rehabilitation using the rehabilitation quality scale (RQS). Statistical analysis of all variables was performed. A p ≤ 0.050 set as criterion for statistical significance.

RESULTS

A total of 153 NNBPP patients and 35 NBPP babies (with 38 nerve transfers) met the inclusion criteria. The mean age at surgery of the NBPP group was 9 months (SD 5.42, range 4 to 23 months). The mean age of NNBPP patients was 22 years (SD 12 years, range 3 to 69). They were operated around sixth months after the trauma. All transfers performed in NBPP patients had a maximum PGS score of 4. This was not the case for the NNBPP population that reached a PGS score of 4 in approximately 20% of the cases. This difference was statistically significant (p < 0.001). The RQS was not significantly different between groups.

CONCLUSION

We found that babies with NBPP have a significantly greater capacity for plastic rewiring than adults with NNBPP. The brain in the very young patient can process the changes induced by the peripheral nerve transfer better than in adults.

[Contralateral C7 Nerve Transfer]

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

A favourable suture method for size-mismatched nerve transfer: a case series of intercostal-to-musculocutaneous nerve transfer for brachial plexus injury

We review a nerve suture method for size-mismatched nerve transfers and report a case series involving patients with brachial plexus injury who underwent intercostal-to-musculocutaneous nerve transfer using this method.

Recovery of Shoulder, Elbow, and Forearm Movement After Nerve Reconstruction for Neonatal Brachial Plexus Palsy

BACKGROUND AND OBJECTIVES

There is a relative dearth of published data with respect to recovery of upper extremity movement after nerve reconstruction for neonatal brachial plexus palsy (NBPP). This study aimed to demonstrate long-term recovery of active range of motion (AROM) at the shoulder, elbow, and forearm after nerve reconstruction for NBPP and to compare that with patients managed nonoperatively.

METHODS

We interrogated a prospectively collected database of all patients evaluated for NBPP at a single institution from 2005 to 2020. AROM measurements for shoulder, elbow, and forearm movements were collected at every visit up to 5 years of follow-up and normalized between 0 and 1. We used generalized estimated equations to predict AROM for each movement within local age windows over 5 years and compared the operative and nonoperative cohorts at each age interval.

RESULTS

In total, >13 000 collected datapoints representing 425 conservatively and 99 operatively managed children were included for analysis. At 5 years, absolute recovery of AROM after nerve reconstruction was ∼50% for shoulder abduction and forward flexion, ∼65% for shoulder external rotation, and ∼75% for elbow flexion and forearm supination, with ∼20% loss of elbow extension AROM. Despite more limited AROM on presentation for the operative cohort, at 5 years, there was no significant difference between the groups in AROM for shoulder external rotation, elbow extension, or forearm supination, and, in Narakas grade 1-2 injury, shoulder abduction and forward flexion.

CONCLUSION

We demonstrate recovery of upper extremity AROM after nerve surgery for NBPP. Despite more severe presenting injury, operative patients had similar recovery of AROM when compared with nonoperative patients for shoulder external rotation, elbow extension, forearm supination, and, for Narakas grade 1-2 injury, shoulder abduction and forward flexion.

Porcine Acellular Nerve-Derived Hydrogel Improves Outcomes of Direct Muscle Neurotization in Rats

Background: The ability to reinnervate a muscle in the absence of a viable nerve stump is a challenging clinical scenario. Direct muscle neurotization (DMN) is an approach to overcome this obstacle; however, success depends on the formation of new muscle endplates, a process, which is often limited due to lack of appropriate axonal pathfinding cues. Objective: This study explored the use of a porcine nerve extracellular matrix hydrogel as a neuroinductive interface between nerve and muscle in a rat DMN model. The goal of the study was to establish whether such hydrogel can be used to improve neuromuscular function in this model. Materials and Methods: A common peroneal nerve-to-gastrocnemius model of DMN was developed. Animals were survived for 2 or 8 weeks following DMN with or without the addition of the hydrogel at the site of neurotization. Longitudinal postural thrust, terminal electrophysiology, and muscle weight assessments were performed to qualify and quantify neuromuscular function. Histological assessments were made to qualify the host response at the DMN site, and to quantify neuromuscular junctions (NMJs) and muscle fiber diameter. Results: The hydrogel-treated group showed a 132% increase in postural thrust at 8 weeks compared with that of the DMN alone group. This was accompanied by an 80% increase in the number of NMJs at 2 weeks, and 26% increase in mean muscle fiber diameter at 8 weeks. Conclusions: These results suggest that a nerve-derived hydrogel may improve the neuromuscular outcome following DNM.

Does supercharging with cross-face nerve graft enhance smile in non-flaccid facial paralysis patients undergoing selective neurectomy?

BACKGROUND

Cross face nerve grafting (CFNG) is a well-established nerve transfer technique in facial reanimation; however, no study has assessed outcome of supercharging the smile with CFNG in patients with synkinesis. The goal of this study was to examine the smile outcome in non-flaccid facial paralysis (NFFP) patients after supercharging with CFNG during selective neurectomy.

METHODS

NFFP patients who underwent CFNG with end-to-side coaptation to a smile branch on the paralyzed side during selective neurectomy were retrospectively identified and their charts were reviewed. Pre-operative and post-operative facial function was assessed with the electronic clinician-graded facial function tool (eFACE), and an automated computer-aided facial assessment tool (Emotrics). Smile metrics were compared pre-operatively, in early post-operative time (EPO, <6 months), and late post-operative time (LPO, >9 months) when CFNG contribution would be expected.

RESULTS

Thirteen cases were performed between June 2019 and December 2021. No objective smile metrics improved following supercharging with CFNG. Oral commissure excursion improved by 1.23 points in eFACE (p = .812), and by 0.84 in Emotrtics (p = .187) from EPO to LPO. EFACE dynamic score was improved by 0.08 points from EPO to LPO (p = .969).

CONCLUSIONS

Using CFNG for supercharging the smile during selective neurectomy in NFFP patients may not enhance smile. Longer term results following supercharging and long term natural history of selective neurectomy should be assessed.

[Femoral nerve repair with autografts for proximal retroperitoneal damage (case report and literature review)]

Femoral nerve damage, especially in proximal retroperitoneal space, is rare. Therefore, surgical strategy is still unclear for these patients. Various specialists discuss repair with autografts or neurotization by the obturator nerve or its muscular branch.

OBJECTIVE

To demonstrate the diagnostic algorithm for proximal femoral nerve injury and favorable outcomes after repair with long autografts.

MATERIAL AND METHODS

We assessed movements and sensitivity using a five-point scale, as well as ultrasound, magnetic resonance imaging and electroneuromyography data in a patient with extended iatrogenic femoral nerve damage before and after repair with long autografts (10.5 cm).

RESULTS AND DISCUSSION

The patient had complete femoral nerve interruption in proximal retroperitoneal space with 10-cm defect that required repair with five autografts from two sural nerves. Postoperative ultrasound and magnetic resonance imaging revealed signs of graft survival and no neuroma within the nerve suture lines. The first signs of motor recovery occurred after 10 months. After 14 months, strength of quadriceps femoris muscle comprised 4 points, and electroneuromyography confirmed re-innervation.

CONCLUSION

Femoral nerve repair with autografts for complete proximal anatomical interruption can provide sufficient restoration of movements and sensitivity. Therefore, this surgical option should be preferred instead of neurotization. Ultrasound, MRI and ENMG are valuable to clarify the diagnosis and state of the autografts.

Targeted Muscle Reinnervation at the Time of Amputation Decreases Recurrent Symptomatic Neuroma Formation

BACKGROUND

Targeted muscle reinnervation (TMR) is an effective technique for the prevention and management of phantom limb pain (PLP) and residual limb pain (RLP) among amputees. The purpose of this study was to evaluate symptomatic neuroma recurrence and neuropathic pain outcomes between cohorts undergoing TMR at the time of amputation (ie, acute) versus TMR following symptomatic neuroma formation (ie, delayed).

METHODS

A cross-sectional, retrospective chart review was conducted using patients undergoing TMR between 2015 and 2020. Symptomatic neuroma recurrence and surgical complications were collected. A subanalysis was conducted for patients who completed Patient-Reported Outcome Measurement Information System (PROMIS) pain intensity, interference, and behavior scales and an 11-point numeric rating scale (NRS) form.

RESULTS

A total of 105 limbs from 103 patients were identified, with 73 acute TMR limbs and 32 delayed TMR limbs. Nineteen percent of the delayed TMR group had symptomatic neuromas recur in the distribution of original TMR compared with 1% of the acute TMR group ( P < 0.05). Pain surveys were completed at final follow-up by 85% of patients in the acute TMR group and 69% of patients in the delayed TMR group. Of this subanalysis, acute TMR patients reported significantly lower PLP PROMIS pain interference ( P < 0.05), RLP PROMIS pain intensity ( P < 0.05), and RLP PROMIS pain interference ( P < 0.05) scores in comparison to the delayed group.

CONCLUSIONS

Patients who underwent acute TMR reported improved pain scores and a decreased rate of neuroma formation compared with TMR performed in a delayed fashion. These results highlight the promising role of TMR in the prevention of neuropathic pain and neuroma formation at the time of amputation.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Surgery for patients with facial palsy in Germany: a diagnosis-related-groups-based nationwide analysis, 2005-2019

PURPOSE

Chronic flaccid paralysis of the facial nerve leads to permanent dysfunction of eye closure, problems with drinking and eating, and lack of emotional expression. Modern facial surgery can help those affected. An analysis of the development of facial surgery in Germany over time is presented.

METHODS

Nation-wide population-baes diagnosis-related case group (DRG) data of virtually all inpatients who underwent facial surgery for facial palsy between 2005 and 2019 were included. Binomial regression models for changes in surgery rates over time were calculated in relation to gender and treating specialty.

RESULTS

Between 2005 and 2019, there were 28,622 inpatient stays for facial surgery. Most surgeries were provided by otolaryngology (39%) and ophthalmology or dentistry, oral and maxillofacial surgery (20% each). The mean treatment rate was 2.33 ± 0.53 surgeries per 100,000 person-years. The surgery rate was highest for nerve reconstruction surgery (0.46 ± 0.15) and static sling surgery (0.44 ± 0.0.16). The greatest increase was seen in men for nerve surgery (3.9-fold; relative risk [RR] = 3.68; confidence interval [CI] = 3.18-4.26) and sling surgery (5.0-fold; RR = 4.25; CI = 3.38-5.33).

CONCLUSIONS

While nerve and sling surgery increased significantly over time, this was less true or not true at all for surgical techniques. Surgical rates and their change over time were greater in men, without explanation from the data.

The masseteric nerve for facial reanimation: Macroscopic and histomorphometric characteristics in 106 human cadavers and comparison of axonal ratio with recipient nerves

Peripheral facial palsy causes severe impairments. Sufficient axonal load is critical for adequate functional outcomes in reanimation procedures. The aim of our study was to attain a better understanding of the anatomy of the masseteric nerve as a donor, in order to optimize neurotization procedures. Biopsies were obtained from 106 hemifaces of fresh frozen human cadavers. Histological cross-sections were fixed, stained with PPD, and digitized. Histomorphometry and a validated software-based axon quantification were conducted. Of the 154 evaluated branches, 74 specimens were of the main trunk (MT), 40 of the anterior branch (AB), and 38 of the descending branch (DB), while two halves of one cadaver featured an additional branch. The MT showed a diameter of 1.4 ± 0.41 mm (n = 74) with 2213 ± 957 axons (n = 55). The AB diameter was 0.9 ± 0.33 mm (n = 40) with 725 ± 714 axons (n = 30). The DB diameter was 1.15 ± 0.34 mm (n = 380) with 1562 ± 926 axons (n = 30). The DB demonstrated a high axonal capacity - valuable for nerve transfers or muscle transplants. Our findings should facilitate a balanced selection of axonal load, and are potentially helpful in achieving more predictable results while preserving masseter muscle function.

Restoring the spontaneous smile through free functional muscle transfer. A systematic review and meta-analysis of the last twenty years' experience

BACKGROUND

The recovery of the spontaneous smile has become a primary focus in facial reanimation surgery and its major determinant is the selected neurotizer. We aimed to compare the spontaneity outcomes of the most preferred neurotization methods in free functional muscle transfer for long-standing facial paralysis.

METHODS

The Embase, Ovid Medline, and PubMed databases were queried with 21 keywords. All clinical studies from the last 20 years reporting the postoperative spontaneity rate for specified neurotization strategies [cross-face nerve graft (CFNG), contralateral facial nerve (CLFN), motor nerve to the masseter (MNM), and dual innervation (DI)] were included. A meta-analysis of prevalence was performed using Freeman-Tukey double arcsine transformation, I2 statistic, and generic inverse variance with a random-effects model. Risk Of Bias In Non-randomized Studies of Interventions and Newcastle-Ottawa scale were used to assess bias and study quality.

RESULTS

The literature search produced 2613 results and 473 unique citations for facial reanimation. Twenty-nine studies including 2046 patients were included in the systematic review. A meta-analysis of eligible data (1952 observations from 23 studies) showed statistically significant differences between the groups (CFNG: 0.94; 95% confidence interval [CI], 0.76-1.00, CLFN: 0.91; 95% CI, 0.49-1.00, MNM: 0.26; 95% CI, 0.05-0.54, DI: 0.98; 95% CI, 0.90-1.00, P < 0.001). In pairwise comparisons, statistically significant differences were found between MNM and other neurotization strategies (P < 0.001 in CFNG compared with MNM, P = 0.013 for CLFN compared with MNM, P < 0.001 for DI compared with MNM).

CONCLUSIONS

DI- and CLFN-driven strategies achieved the most promising outcomes, whereas MNM showed the potential to elicit spontaneous smile at a lower extent. Our meta-analysis was limited primarily by incongruency between spontaneity assessment systems. Consensus on a standardized tool would enable more effective comparisons of the outcomes.

Targeted muscle reinnervation: a brief history of a promising procedure for effective management of amputation pain

Each year, 27.5% of the 150 000 people in the United States who require lower extremity amputation experience significant postoperative complications, including pain, infection, and need for reoperation. Postamputation pain, including RLP and PLP, is debilitating. While the causes of such pain remain unknown, neuroma formation following sensory nerve transection is believed to be a major contributor. Various techniques exist for management of a symptomatic neuroma, but few data exist on which technique is superior. Furthermore, there are few data on primary prevention of neuroma formation following injury or intentional transection. The TMR technique shows promise for both management of PLP and RLP and prevention of neuroma formation. Following amputation, transected sensory nerves are coapted to nearby motor nerve supplying remaining extremity musculature. Not only does this procedure generate increased myoelectric signals for improved prosthesis control, TMR appears to neurophysiologically alter sensory nerves, preventing formation of painful sensory neuromas. The sole RCT to date evaluating the efficacy of TMR showed statistically significant reduction in PLP. TMR is not limited to use in the setting of major limb amputation. It has also been used in the setting of post-mastectomy pain, abdominal wall neuromas, digital amputations, and headache surgeries. This article reviews the origin of TMR and provides a brief description of histologic changes following the procedure, as well as current data regarding the efficacy of TMR with regard to postoperative pain relief. It also seeks to provide a concise, comprehensive resource for providers to facilitate better discussions with patients about treatment options.

Clinical Outcomes of Upper Extremity Nerve Transfers in Neuralgic Amyotrophy

SUMMARY

Neuralgic amyotrophy (NA) is a disease affecting peripheral nerves. Treatment has historically been conservative, as the natural course of the disease was thought to be self-limiting. Recent work has demonstrated that as many as two-thirds of people with NA have persistent pain, fatigue, or weakness. At the authors' center, supercharged end-to-side (SETS) nerve transfers are commonly performed in patients with NA to optimize motor recovery while allowing for native axonal regrowth. The authors describe the technique and clinical outcomes of patients with NA affecting the anterior interosseous nerve (AIN) who were treated with SETS nerve transfer from extensor carpi radialis brevis to AIN. Ten patients (90% male; mean age, 51.3 ± 9.7 years) underwent extensor carpi radialis brevis-to-AIN transfer at a mean period of 6.4 ± 1.4 months after onset of symptoms. Mean postoperative follow-up duration was 14.8 ± 3.2 months. Before surgery, all patients demonstrated clinically significant weakness in the flexor pollicis longus (FPL), flexor digitorum profundus muscle to the index finger (FDP2), or both. FPL strength improved from a median Medical Research Council (MRC) grade of 1.5 to 4 ( P = 0.011) and FDP2 strength improved from a median MRC grade of 1 to 5 ( P = 0.016). A postoperative MRC grade of 4 or greater was achieved in nine of 10 (90%) FPL and 10 of 10 (100%) FDP muscles. This is the first report of SETS nerve transfer for the treatment of NA. The outcomes of this work suggest that SETS nerve transfers may be an option to optimize motor outcomes in patients with NA.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Axillary to Radial Nerve Transfer for Recovery of Elbow Extension After Spinal Cord Injury

BACKGROUND AND OBJECTIVES

Cervical spinal cord injuries (SCI) result in severe loss of function and independence. Nerve transfers have become a powerful method for restoring upper extremity function, the most critical missing function desired by this patient population. Recovery of active elbow extension allows for expansion of one's workspace to reach for objects and stabilizes control at the elbow joint. Without triceps function, a patient with a cervical SCI is rendered entirely helpless when in the supine position. Our objective was to provide a concise description of the transfer of branches of the axillary nerve (AN) to the long head of the triceps branch of the radial nerve (RN) for restoration of elbow extension after cervical SCI.

METHODS

An anterior, axillary approach is used for the transfer of the nerve branches of the AN (which may include branches to the teres minor, posterior deltoid, or even middle deltoid) to the long head of the triceps branch of the RN. Preoperative assessment and intraoperative stimulation are demonstrated to direct optimal selection of axillary branch donors.

RESULTS

The axillary approach provides full access to all branches of the AN in optimal proximity to triceps branches of the RN and allows for tension-free coaptation to achieve successful recovery of elbow extension. Final outcomes may not be achieved for 18 months. Of our last 20 patients with greater than 12-month follow-up, 13 have achieved antigravity strength in elbow extension, 4 are demonstrating ongoing progression, and 3 are definitive failures by 18 months.

CONCLUSION

The axillary to RN transfer is an important intervention for recovery of elbow extension after cervical SCI, which significantly improves quality of life in this patient population. Further large population outcomes studies are necessary to further establish efficacy and increase awareness of these procedures.

A Randomised Control Trial Comparing the Outcomes of Anterior with Posterior Approach for Transfer of Spinal Accessory Nerve to Suprascapular Nerve in Brachial Plexus Injuries

Background: In brachial plexus surgery, a key focus is restoring shoulder abduction through spinal accessory nerve (SAN) to suprascapular nerve (SSN) transfer using either the anterior or posterior approach. However, no published randomised control trials have directly compared their outcomes to date. Therefore, our study aims to assess motor outcomes for both approaches. Methods: This study comprises two groups of patients. Group A: anterior approach (29 patients), Group B: Posterior approach (29 patients). Patients were allocated to both groups using selective randomisation with the sealed envelope technique. Functional outcome was assessed by grading the muscle power of shoulder abductors using the British Medical Research Council (MRC) scale. Results: Five patients who were operated on by posterior approach had ossified superior transverse suprascapular ligament. In these cases, the approach was changed from posterior to anterior to avoid injury to SSN. Due to this reason, the treatment analysis was done considering the distribution as: Group A: 34, Group B: 24. The mean duration of appearance of first clinical sign of shoulder abduction was 8.16 months in Group A, whereas in Group B, it was 6.85 months, which was significantly earlier (p < 0.05). At the 18-month follow-up, both intention-to-treat analysis and as-treated analysis were performed, and there was no statistical difference in the outcome of shoulder abduction between the approaches for SAN to SSN nerve transfer. Conclusions: Our study found no significant difference in the restoration of shoulder abduction power between both approaches; therefore, either approach can be used for patients presenting early for surgery. Since the appearance of first clinical sign of recovery is earlier in posterior approach, therefore, it can be preferred for cases presenting at a later stage. Also, the choice of approach is guided on a case to case basis depending on clavicular fractures and surgeon preference to the approach. Level of Evidence: Level II (Therapeutic).

Secondary dynamic midface reanimation with gracilis free muscle transfer after failed reconstruction attempt: A 15-year experience

BACKGROUND

The quantitative outcome of secondary reanimation after a failed primary reconstruction attempt for facial paralysis is rarely reported in the literature. This study aimed to investigate the feasibility of secondary reanimation with gracilis free muscle transfer (GFMT) and whether this outcome is influenced by the primary reconstruction.

METHODS

Twelve patients with previously failed static procedures (static group, n = 6), temporal muscle transfer (temporal transfer group, n = 2), and GFMT (GFMT group, n = 4) were all secondarily reanimated with GFMT. The clinical outcome was graded with the eFACE metric. The objective oral commissure excursion was measured with Emotrics, and the artificial intelligence software FaceReader evaluated the intensity score (IS) of emotional expression.

RESULTS

The mean follow-up was 40 ± 27 months. The eFACE metric showed a statistically significant (p < 0.05) postoperative improvement in the dynamic and smile scores across all groups. In the GFMT group, oral commissure with smile (75.75 ± 20.43 points), oral commissure excursion while smiling with teeth showing (32.7 ± 4.35 mm), and the intensity of happiness emotion while smiling without teeth showing (IS of 0.37 ± 0.23) were significantly lower as compared with the static group postoperatively (98.83 ± 2.86 points, p = 0.038; 41.7 ± 4.35 mm, p = 0.025; IS 0.83 ± 0.16, p = 0.01).

CONCLUSIONS

Our data suggest that secondary dynamic reconstruction with GFMT is feasible should the primary reconstruction fail. The secondary GFMT appears to improve the outcome of primary GFMT; however, the oral commissure excursion while smiling might be lower than that in patients who had static procedures as primary reconstruction.

Three-dimensional evaluation of symmetry in facial palsy reanimation using stereophotogrammetric devices: A series of 15 cases

Facial palsy can severely compromise quality of life, significantly altering the harmony and symmetry of the face, which can be restored by surgical rehabilitation. The aim of the study was the quantification of facial symmetry following facial reanimation. Fifteen consecutive adult patients were surgically treated through triple innervation for reanimation of flaccid unilateral facial paralysis (contralateral facial nerve, masseteric nerve, and hypoglossal nerve) and fascia lata graft for definition of the nasolabial sulcus. In the preoperative stage and at least 11 months after the surgical treatment, three-dimensional facial images were recorded through stereophotogrammetry in a neutral (rest) position, and with Mona Lisa and full-denture (maximum) smiles. Labial commissure inclination relative to the interpupillary axis, and a surface assessment of local facial asymmetry at rest and while smiling were obtained for the upper, middle, and lower facial thirds. The angle between the interpupillary axis and the labial commissure significantly improved in post-surgical acquisitions, regaining symmetry at rest (t-test; p < 0.001). Facial symmetry increased significantly when passing from pre-to postsurgical facial scans, from the lower to the upper facial third, and from the full smile to the rest position (ANOVA; p < 0.001). After treatment, the full smile recovered more symmetry than the other two expressions. In summary, surgical treatment significantly reduced facial asymmetry, but this reduction differed significantly among the various animations and facial thirds. The results of this study confirmed clinical findings of significant static and dynamic improvements in facial symmetry after triple innervation reanimation surgery.

Donor complications of contralateral C7 nerve transfer in Brachial Plexus Birth Injury: a systematic review

PURPOSE

Contralateral C7 (CC7) nerve transfer is a reconstructive option in the upper limb when there are limited donor options. Promising results have been reported in the adult population but its role in Brachial Plexus Birth Injury (BPBI) is unclear. A major concern with this technique is the potential impact on the contralateral, unaffected limb. Our aim was to review the available literature on the use of this transfer in BPBI, to determine the incidence of short- and long-term deficits at the donor site.

METHODS

The relevant literature was identified from searches of Embase, Ovid Emcare and Ovid MEDLINE, for combinations of terms relating to CC7 nerve transfer and BPBI.

RESULTS

Seventy-five patients were included in this review, from the eight papers that were eligible for inclusion, from a total of 16 papers identified. Patient age ranged from three to 93 months and the shortest follow-up period was six months. Post-operative motor deficits at the donor site included reduced range of shoulder abduction; triceps weakness; and phrenic nerve palsy. All motor deficits recovered within six months. The only sensory deficit reported was reduced sensation in the median nerve distribution which, in all cases, resolved within four weeks. Finally, synchronous donor limb motion and sensation were reported in 46.6% of patients.

CONCLUSION

CC7 nerve transfer in BPBI appears to have few long-term donor limb complications. Sensory and motor deficits are reportedly transient. The impact of synchronous motion and sensation on upper limb function in this patient cohort is not yet known.

Clinical outcomes of corneal neurotization using sural nerve graft in neurotrophic keratopathy

OBJECTIVE

To evaluate the efficacy of corneal neurotisation using sural nerve graft coaptation of the contralateral supratrochlear nerve in unilateral neurotrophic keratopathy and corneal anesthesia. Corneal neuralization has emerged as a potential option in the treatment of neurotropic keratopathy, however not free from the predicament. We evaluated the long-term outcome of corneal neurotisation in the treatment of unresponsive unilateral neurotropic keratopathy using surgical variations to mimic and expedient the surgical procedure.

METHODS

A Prospective interventional study involving patients with unilateral neurotrophic keratopathy (NK) who did not respond to medical measures was conducted. The study parameters evaluated were best-corrected visual acuity improvement, ocular surface evaluation parameters [tear break-up time (TBUT), Schirmer's 1, and ocular surface staining scores (corneal and conjunctival staining)], central corneal sensation (Cochet Bonnet esthesiometer), sub-basal nerve fiber length (SBNFL), and sub-basal nerve fiber density (SBNFD) determined by central confocal microscopy at recruitment and during follow-up at 1-month, 3-month, 6-month, 9-month and 12-month respectively, following corneal neurotization.

RESULTS

Eleven eyes of 11 patients with unilateral neurotrophic keratopathy (NK) who underwent corneal neurotisation were studied. The mean follow-up was 10.09±2.31months (range, 6-12). Mean best corrected visual acuity in log MAR at baseline, 1.35±0.52 improved significantly to 1.06±0.76 (P = 0.012) at 3 months and continued to 0.55±0.60 (P = 0.027) at 12 months. There was a significant reduction in NK grade severity and improvement in the ocular surface as early as 1 month, and central corneal sensations (P = 0.024) as soon as 3 months. Mean corneal SBNF improved from 3.12±1.84 mm/mm2 to 4.49±1.88 at 1 month (P = 0.008), 13.31±3.61 mm/mm2 (P = 0.028) at 12 months. Mean central corneal SBNFD evident at 6 months was 1.83±2.54no/mm2 (P = 0.018) and 4.90±3.12no/mm2 (P = 0.028) at 12 months.

CONCLUSION

This study substantiates the routine practice of corneal neurotisation by simplifying the intricacies observed during the procedure.

Daily Life Impact of Brachial Plexus Reconstruction in Adults: 10 Years Follow-Up

PURPOSE

Reconstructive surgery of brachial plexus injury in adults remains a challenge. Short- and midterm follow-up results have been described in terms of impairments, such as muscle strength grading. However, psychologic management has been shown to be a major contributor in long-term results. A new, specific brachial plexus injury scale, including functional and psychologic components, was described. Objectives of this study were: (1) to assess functional long-term brachial plexus reconstruction outcomes; and (2) to validate the Mancuso scale at 10 years of follow-up.

METHODS

Twenty patients with at least 10 years of follow-up were included in the study. Four patients had C5-C6 palsy and 16 had a C5-T1 injury. Shoulder abduction and elbow flexion were assessed with Medical Research Council grades. Shoulder function was evaluated with a Constant score. The 36-item short-form survey (SF36) was used to assess quality of life, and the quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) was used for patient reports of disability. The Mancuso scale was assessed and correlated to the different scores used.

RESULTS

At the last follow-up, the Medical Research Council grade was at least grade 3 in 10 cases (50%) of shoulder abduction and in 12 cases (60%) of elbow flexion. The Constant score was 31.4 (SD, 15.1). The SF36 score was 67.5 (SD, 4.25) and the QuickDASH was 50 (SD, 15.9). We found a correlation between the symptom score (Mancuso score) and the different quality-of-life scores (QuickDASH: coefficient, 0.491; SF36: coefficient, -0.565; limitations score: coefficient, 0.445).

CONCLUSIONS

This study reported results from the Mancuso scale at a minimum of 10 years of follow-up of reconstructive surgery for brachial plexus injury in adults. Correlations between this composite scale and the SF36 and QuickDASH scores suggest construct validity.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Posterior Deltoid Function After Transfer of Branch to the Long Head Triceps Brachii of the Radial Nerve to the Anterior Branch of the Axillary Nerve

PURPOSE

The aim of this study was to evaluate the function of the posterior part of the deltoid after nerve transfer of the long head triceps branch of the radial nerve to the anterior branch of the axillary nerve in patients with an upper brachial plexus injury or isolated axillary nerve injury.

METHODS

We retrospectively reviewed 26 patients diagnosed with an upper brachial plexus injury or isolated axillary nerve injury who underwent nerve transfer of the long head triceps muscle branch of the radial nerve to the anterior branch of the axillary nerve in our institute between 2012 and 2017. Data on age, sex, the mechanism of injury, the pattern of injury, and operative treatment were collected from medical records. Preoperative and postoperative clinical examinations, including motor powers of shoulder abduction and extension according to Medical Research Council grading, were evaluated. At a minimum of 2 years after the operation, we evaluated the recovery of the posterior deltoid function using the swallow-tail test.

RESULTS

Twenty-two patients (84.6%) had recovery of posterior deltoid function confirmed by the swallow-tail test. There were 23 patients (88.5%) who achieved at least Medical Research Council grade 4 of shoulder abduction.

CONCLUSIONS

Nerve transfer from the branch to the long head triceps to the anterior branch of the axillary nerve is an effective technique for restoring deltoid function in an upper brachial plexus injury or isolated axillary nerve injury. This technique can provide shoulder abduction and shoulder extension, which are the functions of the posterior deltoid muscle.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Effect of shorter nerve graft and selective motor branch of recipient nerve on nerve transfer surgery for elbow flexion in patients with brachial plexus injury

OBJECTIVE

The spinal accessory nerve (SAN) is commonly used as a donor nerve for reinnervation of elbow flexors in brachial plexus injury (BPI) reconstruction. However, no study has compared the postoperative outcomes between SAN-to-musculocutaneous nerve (MCN) transfer and SAN-to-nerve to biceps (NTB) transfer. Thus, this study aimed to compare the postoperative time to recovery of elbow flexors between the two groups.

METHODS

A total of 748 patients who underwent surgical treatment for BPI between 1999 and 2017 were retrospectively reviewed. Among them, 233 patients were treated with nerve transfer for elbow flexion. Two techniques were used to harvest the recipient nerve: the standard dissection technique and the proximal dissection technique. The postoperative motor power of elbow flexion was assessed every month for 24 months using the Medical Research Council (MRC) grading system. Survival and Cox regression analyses were used to compare the time to recovery (MRC grade ≥ 3) between the two groups.

RESULTS

Of the 233 patients who underwent nerve transfer surgery, there were 162 patients in the MCN group and 71 patients in the NTB group. At 24 months after surgery, the MCN group had a success rate of 74.1%, and the NTB group had a success rate of 81.7% (p = 0.208). When compared with the MCN group, the NTB group had a significantly shorter median time to recovery (19 months vs 21 months, p = 0.013). Only 11.1% of patients in the MCN group regained MRC grade 4 or 5 motor power 24 months after nerve transfer surgery compared with 39.4% patients in the NTB group (p < 0.001). Cox regression analysis showed that the SAN-to-NTB transfer in combination with the proximal dissection technique was the only significant factor affecting time to recovery (HR 2.33, 95% CI 1.46-3.72; p < 0.001).

CONCLUSIONS

SAN-to-NTB transfer in combination with the proximal dissection technique is the preferred nerve transfer option for restoration of elbow flexion in traumatic pan-plexus palsy.

Median to Radial Nerve Transfer: An 8-Year Experience From a Lower-Middle Income Country

INTRODUCTION

With an incidence of 2-16%, radial nerve palsy is one of the common forms of nerve injuries globally. Radial nerve palsy causes debilitating effects including loss of elbow extension, wrist drop and loss of finger extension. Reparative surgical pathways range from primary repair and neurolysis, to nerve grafting, nerve transfers, and tendon transfers. Due to ease of performance and acceptability and reproducibility of outcomes, tendon transfers are considered the gold standard of radial nerve palsy repair. However, independent finger function cannot be achieved and as such may not give truly desirable results. In lower-middle income countries, the question of nerve transfer versus tendon transfer for patients who are keen to get back to work is key. While tendon transfer recovery is faster, the functional loss is often considered devastating for fine hand function due to loss of grip secondary to lack of wrist and finger extension. In this study, we present our experience of performing median nerve transfers for radial nerve palsy in Pakistan.

METHODS

We performed a retrospective case-series of patients undergoing median to radial nerve transfer for radial nerve palsy over a period of 6 y, from 2012 to 2019. Patients with radial nerve palsy were diagnosed via electromyography and nerve conduction studies. The procedure involved coapting the branches of the flexor carpi radialis and flexor digitorum superficialis (long and ring finger) nerves to the posterior interosseous nerve and extensor carpi radialis brevis, respectively. Patients were assessed using the Medical Research Council scale for muscle strength of wrist, finger and thumb extension separately at 1 y time. Our results were then compared to results from similar nerve transfer studies.

RESULTS

We operated on 10 right-hand dominant patients, eight males and two females with a median age of 33 y (6-63 y). four sustained injury to the right hand and six to the left. Causes of the injuries included road traffic accident (n = 3), firearm injury (n = 4), shrapnel (n = 1), iatrogenic injury (injection in deltoid region (n = 1) and fall (n = 1). Types of fracture included mid humerus fracture, fracture of the surgical neck of the humerus, and supracondylar fracture of the humerus. Median time to surgery since injury was 4 mo (1-8 mo). Independent wrist extension was M4+ in all patients and independent finger extension was M4+ in seven and M4-in two patients. However, a patient who presented late at 8 mo had poorer finger outcomes with extension at M2-. All patients had independent movement of fingers.

CONCLUSIONS

Nerve transfer is a reliable method of post traumatic nerve repair and reinnervation, particularly in lower-middle income countries, even in cases where the nerve damage is severe and extensive and up to 6 mo may have elapsed between injury and presentation. Timely median to radial nerve transfer is a highly recommended option for radial nerve palsy, with regular follow-ups and physical therapy added to ensure positive outcomes.

Semiscleral Contact Lens Use After Direct Corneal Neurotization for Neurotrophic Keratopathy

PURPOSE

To describe a case of a patient treated for neurotrophic keratopathy (NK) with direct corneal neurotization (CN), where a modification to the CN technique allowed for semiscleral contact lens use postoperatively.

OBSERVATION

Our patient had successful CN with improved corneal sensation. During the procedure, a 1.0 mm gutter was created between the limbus and nerve graft to allow for semiscleral contact lens fitting.

CONCLUSIONS

With the use of preoperative planning and a limbal gutter during CN, a semiscleral contact lens can serve as a well-tolerated postoperative management option to improve visual acuity and protect the corneal surface in patients with NK.

Optimizing Facial Function in Patients With High-Risk Recurrent Pleomorphic Adenoma and a History of Facial Nerve Injury

BACKGROUND

Parotid pleomorphic adenoma (PA) patients present significant diagnostic and surgical challenges rendering them high risk for facial nerve injury. Recurrent PA patients often present with history of facial nerve injury or previous reanimations making salvage of the facial nerve or previous reanimations significantly more complex. The study aim is to share our experience with this high risk for facial nerve injury population and review the literature.

METHODS

Adult patients with recurrent PA and history of facial nerve injury with at least 3 months of follow-up were analyzed for demographics, facial palsy history, previous head and neck surgeries, previous facial paralysis reconstruction, preoperative imaging, surgical approach, and postoperative outcomes.

RESULTS

Four female patients were identified with an average age of 62 years. All patients underwent an initial protective dissection of the facial nerve or previous reanimation reconstruction by the facial nerve reconstructive team followed by the extirpative team. The average number of previous head and neck surgeries was 5, the number of recurrences was 2, and follow-up was 20 months. Half had prior dynamic facial reanimation. Two patients underwent complete preextirpative dissection of the facial nerve resulting in neuropraxia, which recovered completely after an average of 143 days. A third patient presented with 2 recurrences, both during and after reanimation with a dually innervated free functional muscle transfer. The reconstruction was salvaged, and motion was achieved. A fourth patient presented with benign preoperative findings, but intraoperative findings confirmed malignancy, necessitating facial nerve sacrifice, followed by immediate intratemporal grafting of the facial nerve and masseteric nerve transfer. Motion appeared 139 days postoperatively.

CONCLUSIONS

A multidisciplinary effort should be implemented in this high risk for facial nerve injury population with the primary goal of protecting the facial nerve or any previous reanimation procedures, yet with preparedness to apply any reconstructive strategy based on intraoperative findings.

Diagnostic Accuracy of Manual Muscle Testing to Identify Nerve Transfer Candidates in Children with Acute Flaccid Myelitis

BACKGROUND

Manual muscle testing is a mainstay of strength assessment despite not having been compared with intraoperative electrical stimulation of peripheral nerves.

METHODS

Intraoperative electrical stimulation served as the reference standard in evaluating predictive accuracy of the Active Movement Scale (AMS) and the Medical Research Council (MRC) scale. Retrospective consecutive sampling of all patients with AFM who underwent exploration or nerve transfer at a pediatric multidisciplinary brachial plexus and peripheral nerve center from March of 2016 to July of 2020 were included. The nonparametric area under the curve (AUC) was calculated. Optimal cutoff score (Youden J ) and diagnostic accuracy values were reported. The AMS and MRC scale were directly compared for predictive superiority.

RESULTS

A total of 181 upper extremity nerves (73 donor nerve candidates and 108 recipient nerve candidates) were tested intraoperatively from 40 children (mean age ± SD, 7.9 ± 4.9 years). The scales performed similarly ( P = 0.953) in classifying suitable donor nerves with satisfactory accuracy (AUC AMS , 71.5%; AUC MRC , 70.7%; optimal cutoff, AMS >5 and MRC >2). The scales performed similarly ( P = 0.688) in classifying suitable recipient nerves with good accuracy (AUC AMS , 92.1%; AUC MRC :, 94.9%; optimal cutoff, AMS ≤3 and MRC ≤1).

CONCLUSIONS

Manual muscle testing is an accurate, noninvasive means of identifying donor and recipient nerves for transfer in children with acute flaccid myelitis. The utility of these results is in minimizing unexpected findings in the operating room and aiding in the development of contingency plans. Further research may extend these findings to test the validity of manual muscle testing as an outcome measure of the success of nerve transfer.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Diagnostic, I.

Perineurial Window is Critical for Experimental Reverse End-to-Side Nerve Transfer

BACKGROUND

The depth of connective tissue window in the side of a recipient nerve in reverse end-to-side transfers (RETS) remains controversial.

OBJECTIVE

To test whether the depth of connective tissue disruption influences the efficiency of donor axonal regeneration in the context of RETS.

METHODS

Sprague-Dawley rats (n = 24) were assigned to 1 of the 3 groups for obturator nerve to motor femoral nerve RETS: group 1, without epineurium opening; group 2, with epineurium only opening; and group 3, with epineurium and perineurium opening. Triple retrograde labeling was used to assess the number of motor neurons that had regenerated into the recipient motor femoral branch. Thy1-GFP rats (n = 8) were also used to visualize the regeneration pathways in the nerve transfer networks at 2- and 8-week time point using light sheet fluorescence microscopy.

RESULTS

The number of retrogradely labeled motor neurons that had regenerated distally toward the target muscle was significantly higher in group 3 than that in groups 1 and 2. Immunohistochemistry validated the degree of connective tissue disruption among the 3 groups, and optical tissue clearing methods demonstrated donor axons traveling outside the fascicles in groups 1 and 2 but mostly within the fascicles in group 3.

CONCLUSION

Creating a perineurial window in the side of recipient nerves provides the best chances of robust donor axonal regeneration across the RETS repair site. This finding aids nerve surgeons by confirming that a deep window should be undertaken when doing a RETS procedure.

Nerve guide conduits, nerve transfers, and local and free muscle transfer in facial nerve palsy

PURPOSE OF REVIEW

To highlight the recent literature on reinnervation options in the management of facial nerve paralysis using nerve conduits, and nerve and muscle transfers.

RECENT FINDINGS

Engineering of natural and synthetic nerve conduits has progressed and many of these products are now available on the market. The use of the masseter nerve has become more popular recently as a choice in nerve transfer procedures due to various unique advantages. Various authors have recently described mimetic muscle reinnervation using more than one nerve transfer, as well as dual and triple innervation of free muscle transfer.

SUMMARY

The ideal nerve conduit continues to be elusive, however significant progress has been made with many natural and synthetic materials and designs tested and introduced on the market. Many authors have modified the classic approaches in motor nerve transfer, as well as local and free muscle transfer, and described new ones, that aim to combine their advantages, particularly the simplification to a single stage and use of multiple reinnervation to the mimetic muscles. These advances are valuable to the reconstructive surgeon as powerful tools that can be tailored to the unique challenges of patients with facial nerve palsy looking for dynamic reanimation options.

Extra- and intramuscular innervation of the masseter: Implications for facial reanimation

PURPOSE

Irreversible facial paralysis results in significant functional impairment. The motor nerve to the masseter is a reconstructive option, but despite its clinical importance, there are few parametric anatomic studies of the masseteric nerve. The purpose of this study was to investigate the extra- and intramuscular innervation of the masseter in 3D to determine the relationship of the nerve to the muscle heads and identify landmarks to aid identification.

MATERIALS AND METHODS

The nerve was dissected throughout its entire course in eight formalin-embalmed cadaveric specimens (mean age 84.9 ± 12.2 years). The nerve was digitized at 1-2 mm intervals using a MicroScribe™ digitizer and modeled in 3D in Autodesk® Maya®.

RESULTS

Two or three extramuscular nerves were found to enter the deep head (DH) of the masseter: one main "primary" nerve (n = 8) and one (n = 4) or two (n = 4) smaller primary nerve(s). The main primary nerve supplied both the deep and superficial heads, whereas the smaller primary nerve(s) only supplied the DH. Surgical landmarks for masseter nerve localization were quantified.

CONCLUSIONS

Comprehensive mapping of the innervation of the masseter muscle throughout its volume revealed neural partitioning that could provide a basis for safety planning for muscle flaps and donor nerve identification and explain why masseter functional loss is not incurred by donor nerve sacrifice. Quantified landmarks correlate to previous studies and support the constant anatomy of this nerve. Our results provide a basis to optimize surgical approaches for donor nerve and muscle flap surgery.

Age-related outcomes of facial reanimation surgery using gracilis free functional muscle transfer innervated by the masseteric nerve: A retrospective cohort study

BACKGROUND

The free functional muscle gracilis transfer is an established approach in facial reanimation surgery; however, the significance of its neurotization and the patient's age is still inconclusive. Several donor nerves are available for facial reanimation using the free functional gracilis muscle transfer.

OBJECTIVE

This retrospective cohort study investigates whether the masseteric nerve is an equally reliable donor nerve in both older and younger patients.

METHODS

We included 46 patients (13-71 years, male and female) who underwent nerve-to-masseter (NTM)-driven free functional muscle transfer (FFMT) between January 2008 and December 2019. Patients were distributed into three cohorts according to their age at surgery. We assessed the facial symmetry before and after surgery using the pupillo-modiolar angle. Commissure height and excursion deviation were measured with the Emotrics software. Patient-reported outcome measurements were taken using the Facial Clinimetric Examination (FaCE) scale.

RESULTS

All patients had successful flap innervation, except for one patient in the middle-aged cohort (31-51 years). The postoperative facial symmetry at rest, smiling, and laughing was analyzed with the pupillo-modiolar angle and the Emotrics software and showed similar results between all cohorts. The FaCE scale showed similar scores for the middle-aged (31-51 years) cohort and the senior cohort (52-71 years). The social function score in the senior cohort was higher than in the middle-aged cohort, without statistical significance. One patient in the middle-aged (31-51 years) cohort and the senior cohort (52-71 years), respectively, underwent emergency revision due to impaired flap perfusion and could be salvaged.

CONCLUSIONS

NTM-driven FFMT for facial reanimation is a safe and reliable procedure across all age groups of patients.