Evidence-Based Approach to Timing of Nerve Surgery: A Review

Iatrogenic Common Peroneal Nerve Injuries From Inside-out Lateral Meniscus Repair: A Report of 2 Cases

CASES

We report 2 cases of common peroneal nerve (CPN) palsy after inside-out lateral meniscus (LM) repair with very different presentations, occurring despite the standard surgical precautions (open counter incision and proper retraction between the biceps femoris tendon, lateral gastrocnemius, and capsule). On exploration, needle was found to have penetrated the nerve in one case and the nerve sheath in the other case. Patient 1 had near-complete neurological recovery, while patient 2 had partial neurological recovery after suture removal and neurolysis.

CONCLUSION

CPN palsy can occur despite following all precautions during LM repair and should be managed as an iatrogenic injury unless proven otherwise.

Electrospun PCL Nerve Wrap Coated with Graphene Oxide Supports Axonal Growth in a Rat Sciatic Nerve Injury Model

Background/Objectives: Peripheral nerve injuries (PNIs) are a debilitating problem, resulting in diminished quality of life due to the continued presence of both chronic and acute pain. The current standard of practice for the repair of PNIs larger than 10 mm is the use of autologous nerve grafts. Autologous nerve grafts have limitations that often result in outcomes that are not sufficient to remove motor and sensory impairments. Bio-mimetic nanocomposite scaffolds combined with mesenchymal stem cells (MSCs) represent a promising approach for PNIs. In this study, we investigated the potential of an electrospun wrap of polycaprolactone (PCL) + graphene oxide (GO), with and without xenogeneic human adipose tissue-derived MSCs (hADMSCs) to use as a platform for neural tissue engineering. Methods: We evaluated, in vitro and in vivo, the potential of the nerve wrap in providing support for axonal growth. To establish the rat sciatic nerve defect model, a 10 mm long limiting defect was created in the rat sciatic nerve of 18 Lewis rats. Rats treated with the nanocomposites were compared with autograft-treated defects. Gait, histological, and muscle analyses were performed after sacrifice at 12 weeks post-surgery. Results: Our findings demonstrate that hADMSCs had the potential to transdifferentiate into neural lineage and that the nanocomposite successfully delivered hADMSCs to the injury site. Histologically, we show that the PCL + GO nanocomposite with hADMSCs is comparable to the autologous nerve graft, to support and guide axonal growth. Conclusions: The novel PCL + GO nerve wrap and hADMSCs used in this study provide a foundation on which to build upon and generate future strategies for PNI repair.

Neurological Complications following Surgical Treatments of the Lower Molars

Aim

The current review aims to explore postoperative neurological complications in third molar extractive surgery.

Materials and Methods

The PRISMA protocols were followed when conducting this review. We found a total of 2,250 articles that matched our topic using the Boolean keywords, mandibular nerve complications AND oral surgery, from PubMed (1,083), Scopus (435), and Web of Science (732), with the filters of English language articles, time range January 1, 2003, to September 30, 2023, and human studies. After 762 duplicates were eliminated, there remained 1,488 articles. Eleven final articles were deemed of the highest relevance to our topic by eliminating articles in animals, non-English language, reviews, meta-analysis, and off-topic. A potential risk in the third molar extraction was temporary loss of sensibility often caused by mild compression or irritation of the mandibular nerve. This typically resolves within weeks or months, but in severe cases, recovery might take longer. Permanent loss of sensation can occur, indicating significant nerve damage and lasting effects on touch, temperature, or pain perception.

Conclusions

Various treatments exist for nerve damage, including low-level laser therapy, pain management medications, or physical therapy. While these therapies may improve neurosensory impairment, patients often report a decline in their quality of life.

The Role of Length of Nerve Grafts in Combination with Free Functional Muscle Transplantation for Brachial Plexus Injury: A Single-Center Experience

PURPOSE

Extensive lesions of the brachial plexus, or late cases, require free functional muscle grafts because the expected recovery time exceeds the critical threshold of 1.5 years, beyond which irreversible damage may be expected in the distal nerve stump and in the muscle. The reconstructive concept consists of a two-stage procedure where, in the first step, a nerve transfer is performed (from ipsi- or contralateral donor nerves). In the second step, after successful axonal regeneration within the graft has been confirmed, a free muscle transfer is performed. These grafts often exceed 40 cm in length, particularly for contralateral transfers. The purpose of this study was to assess whether robust motor recovery could be supported by such long nerve grafts.

METHODS

From April 2004 to April 2023, a total of 327 free functional muscle transfers were performed, the nerve graft length ranging from 0 cm (direct coaptation) to 90 cm (serial grafts). Motor recovery was evaluated 1.5 years after surgery according to the MRC scale.

RESULTS

A total of 208 patients were available for follow up. Direct coaptation yielded the best results, with 83% of patients reaching an M3 or M4 level of muscle strength. With the application of long (30-60 cm) grafts, 73% of the patients were classified as M3 or M4. The application of serial nerve grafts, however, only resulted in 18% of patients achieving a motor recovery rating of M3.

CONCLUSIONS

These findings demonstrate that robust motor regeneration is supported by long (30-60 cm) nerve grafts, whereas serial nerve grafting results in a marked reduction in the quality of regeneration.

Clinical Practice Guideline: The Treatment of Peripheral Nerve Injuries

BACKGROUND

Nerve lesions often heal incompletely, leading to lifelong functional impairment and high costs for the health care system. The updated German clinical practice guideline is intended to promote the early recognition of nerve lesions and the timely initiation of proper treatment for optimal restoration of function.

METHODS

The recommendations are based on an assessment of all the evidence revealed by a systematic search of the literature, as well as on the expertise of the multiprofessional guideline group.

RESULTS

Only a few publications contain high-quality evidence. This version of the guideline contains a more detailed discussion of war injuries, iatrogenic injuries, MR neurography, and specific treatments than the previous version. As for the different methods of nerve replacement, a comparison of autologous transplantation versus the use of conduits and tubes revealed no significant difference between these two methods on the mBMRC scale, and minimal superiority of autologous transplantation with respect to two-point discrimination. As for the use of nerve transfers when nerve reconstruction is not feasible or unlikely to succeed, nerve transfer yielded slightly better results than proximal reconstruction for elbow flexion, but the difference did not reach statistical significance (mBMRC ≥ 3: RR 1.16, 95% confidence interval [1.02; 1.32]). The treatment of neuromas with targeted muscle reinnervation was superior to the classic approach in decreasing both stump pain (MD 2.0 +/- 2.8) and phantom limb pain (MD 3.4 +/- 4.03).

CONCLUSION

The delayed or improper treatment of peripheral nerve lesions can lead to severe impairment. Timely diagnosis, the use of appropriate treatments in conformity with the guidelines, and interdisciplinary collaboration among specialists are all essential for optimizing the outcome.

Timing of surgical intervention in peripheral nerve injuries from gunshot wounds: Management and review of the literature

Background

Gunshot wounds (GSWs) can result in various peripheral nerve injuries (PNIs), ranging from direct nerve transection to neuropraxia caused by the ballistic shockwave mechanism. PNIs from GSWs can be treated with either early or delayed intervention, with the literature supporting both approaches and sparking a debate between early and delayed intervention for PNIs from GSWs. Here, we present a case that underwent delayed exploration of the right common peroneal nerve after GSW and a literature review comparing early versus delayed intervention for PNIs from GSWs.

Case Description

A 29-year-old male underwent right common peroneal nerve exploration 2 months after he sustained a GSW to the right lower extremity at the level of the fibular head tracking to the lateral malleolus. Initially, after the injury, he was offered supportive care. On evaluation, 1 month later, he reported a right-sided foot drop and paresthesias in the right lower extremity. A partial-thickness injury of the right peroneal nerve was seen on ultrasound, and a bullet fragment in the distal right lower extremity was revealed on computed tomography. The surgical intervention consisted of the right common peroneal nerve decompression proximally to distally and removal of the bullet fragment. Postoperatively, the patient did well with improvements in his right ankle dorsiflexion and plantar flexion seen at his 1.5-month follow-up visit.

Conclusion

Many factors must be considered when treating PNIs from GSWs. For each case, clinical judgment, injury mechanism, and risk-benefit analysis must be evaluated to determine each patient's optimal treatment strategy.

Palsy of Both the Tibial Nerve and Common Peroneal Nerve Caused by a Ganglion Cyst in the Popliteal Area

A ganglion cyst is a benign mass consisting of high-viscosity mucinous fluid. It can originate from the sheath of a tendon, peripheral nerve, or joint capsule. Compressive neuropathy caused by a ganglion cyst is rarely reported, with the majority of documented cases involving peroneal nerve palsy. To date, cases demonstrating both peroneal and tibial nerve palsies resulting from a ganglion cyst forming on a branch of the sciatic nerve have not been reported. In this paper, we present the case of a 74-year-old man visiting an outpatient clinic complaining of left-sided foot drop and sensory loss in the lower extremity, a lack of strength in his left leg, and a decrease in sensation in the leg for the past month without any history of trauma. Ankle dorsiflexion and great toe extension strength on the left side were Grade I. Ankle plantar flexion and great toe flexion were Grade II. We suspected peroneal and tibial nerve palsy and performed a screening ultrasound, which is inexpensive and rapid. In the operative field, several cysts were discovered, originating at the site where the sciatic nerve splits into peroneal and tibial nerves. After successful surgical decompression and a series of rehabilitation procedures, the patient's neurological symptoms improved. There was no recurrence.

Entrapment of median nerve after elbow fracture dislocations: expected surgical time frame based on cadaver study

INTRODUCTION

Median nerve injuries occur in approximately 3% of pediatric elbow fracture dislocations. These rare injuries can be difficult to diagnose, and the results are poor in delay cases. Surgical timing is one of the most important prognostic factors. We aimed to present three patients with median nerve palsy who were referred to our clinic late, and according to these cases, we emphasized the expected time frame for exploration based on our anatomical cadaver study.

MATERIALS AND METHODS

Between 2008 and 2010, three patients were referred to our clinic because of median nerve paralysis after a treated elbow dislocation. The mean interval between injury and referral was 15 (min: 13-max: 18) months, and the mean age of the patients was 15 (13-18) years. Neurolysis was performed in two patients, and for the third patent, after neurolysis, axonal continuity was observed to be disrupted so sural nerve grafting was performed with four cables. Tendon transfers were performed in all patients. A total number of 20 upper extremities of 10 cadavers were dissected. Due to its proximal innervation and ease of assessment, the muscle innervation of the flexor pollicis longus (FPL) was planned to be evaluated. The distance from the medial epicondyle is calculated in the cadaver study where the nerve injury is found.

RESULTS

The mean length from the medial epicondyle to the motor innervation of FPL was calculated in each specimen and found to be 101.99 millimeters (mm) (range: 87.5-134.2). The mean longest innervation of FPL was 110.83 mm from (range 87.5-148.1) the medial epicondyle calculated by including each specimens longest nerve length. Knowing that the healing time of a nerve lesion is 1 mm per day, we calculated that the recovery of FPL would take approximately 4 months.

CONCLUSION

When nerve healing is expected to be 1 mm a day in axonotmesis type injury, after the median nerve palsy following elbow dislocation, thumb flexion should be achieved in the following 4 months generally if the nerve was not entrapped in the joint. This cadaver-based study objectively defined how long to wait for the innervation of the FPL in median nerve injuries in elbow fracture dislocations.

Remodeling of Neuromuscular Junctions in Target Muscle Following Nerve Regeneration in Mice After Delayed Peripheral Nerve Repair

Peripheral nerve injury (PNI) induces severe functional loss in extremities. Progressive denervation and atrophy occur in the muscles if the nerve repair is delayed for long periods of the time. To overcome these difficulties, detailed mechanisms should be determined for neuromuscular junction (NMJ) degeneration in target muscles after PNI and regeneration after nerve repair. We established two models of end-to-end neurorrhaphy and allogeneic nerve grafting in the chronic phase after common peroneal nerve injury in female mice (n = 100 in total). We evaluated motor function, histology, and gene expression in the target muscles during their regeneration processes and compared the models. We found that the functional recovery with allogeneic nerve grafting was superior to that with end-to-end neurorrhaphy, and the number of reinnervated NMJs and Schwann cells was increased at 12 weeks after allograft. In addition, NMJ- and Schwann cell-related molecules showed high expression in the target muscle in the allograft model. These results suggest that Schwann cell migrating from the allograft might play a crucial role in nerve regeneration in the chronic phase after PNI. The relationship between the NMJ and Schwann cells should be further investigated in the target muscle.

Longitudinal traumatic peripheral nerve injury recovery: quantitative description, classification and prediction

Aim: Repair of peripheral nerves is recommended following transection. Systematic evaluation of longitudinal recovery in injury models is needed to improve patient management. Gompertz function provided straightforward interpretation and prediction of recovery outcomes. Materials & methods: Behavioural sciatic function index, measured 3 days post injury, and weekly for 12 weeks following full nerve transection and repair (n = 6) as well as crush injuries (n = 6). Results: Gompertz parametrization provided early classification between types of traumatic peripheral nerve injuries following surgical repair. Results distinguished injury nerves (A: p < 0.01; T_i: p < 0.05; Ic: p < 0.05 and outcome: p < 0.01). Early prognostication of outcomes (crush: 5.5 ± 0.3 and cut/repair: 8 ± 1 weeks) preceded current methods. Conclusion: Our findings identify injury type, state of recovery and early prognostication of outcome.

Avive Soft Tissue Membrane Improves Outcomes of Revision Upper-extremity Nerve Decompression Surgery

Revision nerve decompression remains a challenge for surgeons. Avive Soft Tissue Membrane is processed human umbilical cord membrane that may reduce inflammation and scarring, thereby improving tissue gliding. Although synthetic conduits have been reported in revision nerve decompression, the use of Avive has not.

Methods

Prospective study of revision nerve decompression with Avive application. VAS pain, two-point discrimination, Semmes-Weinstein, pinch and grip strength, range of motion, Quick Disability of Arm, Shoulder & Hand (QuickDASH), and satisfaction were recorded. Using a propensity-matched cohort, VAS pain and satisfaction were retrospectively collected to compare with cohort outcomes.

Results

In the Avive cohort, 77 patients (97 nerves) were included. Mean follow-up was 9.0 months. Avive was applied to the median nerve in 47.4%, ulnar nerve in 39.2%, and radial nerve in 13.4%. VAS pain was 4.5 preoperatively and 1.3 postoperatively. S4 sensory recovery was achieved in 58% of patients, S3+ in 33%, S3 in 7%, S0 in 2%, and improvement from baseline in 87%. Strength improved in 92%. Mean total active motion was 94.8%. Mean QuickDASH score was 36.1, and 96% reported improved or resolved symptoms. Preoperative pain was not significantly different between Avive cohort and controls (P = 0.618). Postoperative pain was significantly lower in cohort patients (1.3 ± 2.2 versus 2.7 ± 3.0, P = 0.001). In the Avive cohort, more had improved or resolved symptoms (P < 0.0001). Clinically important improvement in pain was reported in 64.9% of Avive group patients versus 40.8% of controls (P = 0.002).

Conclusion

Avive contributes to improved outcomes in revision nerve decompression.

Advances of Direct Peripheral Nerve Repair Techniques: Do We Already Have Enough Scientific Evidence?

Purpose

To systematically review the evidence of direct peripheral nerve repair techniques and to determine any differences in outcomes that would guide rational treatment. Additionally, we compare the results and outcomes of these studies and find future directions for peripheral nerve repair techniques.

Methods

We searched PubMed, Virtual Health Library, and Embase databases to identify articles involving direct peripheral nerve techniques. We analyzed and compared the results and outcomes of these techniques. We also aimed to look for the differences in outcomes that would guide the current and future treatments.

Results

We identified 1390 articles, and 19 met our criteria with evidence ranging from level I to level IV. The nerve repair techniques included direct repair, epineural repair, fascicular repair, and group fascicular repair. These nerve techniques are based on the surgeons' personal experience. The results and the outcome of these studies were based on prognostic factors and not on surgical techniques. Few studies compared the surgical techniques and found no significant difference in nerve repair techniques.

Conclusions

Analyzing all direct peripheral nerve techniques and literature of all levels of evidence, our data show no significant difference between different suturing techniques. Currently, there is a lack of scientific evidence on the best direct peripheral nerve repair techniques. Therefore, we need more research to understand the rational treatment methods for peripheral nerve injuries.

Level of evidence

IV.

Risk prediction model for unsuccessful elbow flexion recovery after nerve transfer surgery in patients with brachial plexus injury

OBJECTIVE

Nerve transfer surgery has been a mainstay treatment of brachial plexus injury, with varying success rates. Patients undergoing unsuccessful surgery are left with a useless limb for at least 2 years. Preoperative prediction has become a topic of interest to avoid an unsuccessful nerve transfer surgery. This study aimed to find strong predictive factors and develop a prediction model for unsuccessful functional elbow flexion recovery 2 years after a nerve transfer surgery in patients with brachial plexus injury.

METHODS

This retrospective study reviewed the medical records of 987 patients with traumatic brachial plexus injury who underwent brachial plexus surgery by five hand and microsurgery surgeons at a single tertiary care referral center from December 2001 to July 2018. Four hundred thirty-three patients were eligible for analysis. Patient demographic data, injury factors, surgical details, and postoperative factors were collected. Multivariable logistic regression was used to identify strong prognostic factors for unsuccessful nerve transfer surgery for elbow flexion. A simplified model was developed by rounding the coefficient to the nearest 0.5 score or an integer. Both original and simplified models were validated using the Hosmer-Lemeshow goodness-of-fit test and bootstrapping.

RESULTS

A full, original prognostic model from a stepwise backward logistic regression consisted of a BMI ≥ 23 kg/m2 (p = 0.015), smoking (p = 0.046), total arm-type injury (p = 0.033), donor nerve (p < 0.001), associated upper-extremity fracture (p = 0.013), and associated ipsilateral vascular injury (p = 0.095). The areas under the receiver operating characteristic curve of the original and simplified models were 0.765 and 0.766, respectively. The Hosmer-Lemeshow test showed good agreement of predicted and observed probability of the original (p = 0.49) and simplified (p = 0.19) models. Bootstrapping estimated an average optimism (1.9%) in the original model and minimal optimism (0.1%) in the simplified model.

CONCLUSIONS

The prediction model for failed elbow flexion recovery after nerve transfer surgery in traumatic brachial plexus injury was developed with good predictive value and internal validity. An alternative treatment, i.e., primary free functioning muscle transfer, should be offered in preoperative counseling in cases of a very high risk of failure.

Promoting Nerve Regeneration: Electrical Stimulation, Gene Therapy, and Beyond

Peripheral nerve injuries often result in life-altering functional deficits even with optimal management. Unlike the central nervous system, peripheral nerves have the ability to regenerate lost axons after injury; however, axonal regeneration does not equate to full restoration of function. To overcome this physiological shortcoming, advances in nerve regeneration and repair are paramount, including electrical stimulation, gene therapy, and surgical technique advancements.

Gunshot Wounds: Ballistics, Pathology, and Treatment Recommendations, with a Focus on Retained Bullets

As the epidemic of gunshot injuries and firearm fatalities continues to proliferate in the United States, knowledge regarding gunshot wound (GSW) injury and management is increasingly relevant to health-care providers. Unfortunately, existing guidelines are largely outdated, written in a time that high-velocity weapons and deforming bullets were chiefly restricted to military use. Advances in firearm technology and increased accessibility of military grade firearms to civilians has exacerbated the nature of domestic GSW injury and complicated clinical decision-making, as these weapons are associated with increased tissue damage and often result in retained bullets. Currently, there is a lack of literature addressing recent advances in the field of projectile-related trauma, specifically injuries with retained bullets. This review aims to aggregate the available yet dispersed findings regarding ballistics, GSW etiology, and treatment, particularly for cases involving retained projectiles.

Ballistic peripheral nerve injuries: basic concepts, controversies, and proposal for a management strategy

Ballistic injuries to peripheral nerves are devastating injuries frequently encountered in modern conflicts and civilian trauma centers. Such injuries often produce lifelong morbidity, mainly in the form of function loss and chronic pain. However, their surgical management still poses significant challenges concerning indication, timing, and type of repair, particularly when they are part of high-energy multi-tissue injuries. To help trauma surgeons, this article first presents basic ballistic concepts explaining different types of missile nerve lesions, described using the Sunderland classification, as well as their usual associated injuries. Current controversies regarding their surgical management are then described, including nerve exploration timing and neurolysis's relevance as a treatment option. Finally, based on anecdotal evidence and a literature review, a standardized management strategy for ballistic nerve injuries is proposed. This article emphasizes the importance of early nerve exploration and provides a detailed method for making a diagnosis in both acute and sub-acute periods. Direct suturing with joint flexion is strongly recommended for sciatic nerve defects and any nerve defect of limited size. Conversely, large defects require conventional nerve grafting, and proximal injuries may require nerve transfers, especially at the brachial plexus level. Additionally, combined or early secondary tendon transfers are helpful in certain injuries. Finally, ideal timing for nerve repair is proposed, based on the defect length, associated injuries, and risk of infection, which correlate intimately to the projectile velocity.