An Evidence-Based Structured Review to Assess the Results of Common Peroneal Nerve Repair

An Updated Evaluation of the Management of Nerve Gaps: Autografts, Allografts, and Nerve Transfers

Within the past decade, there have been multiple innovations in the field of nerve surgery. In this review, we highlight critical changes and innovations that have helped advance the field and present opportunities for further study. This includes the modification and clarification of the classification schema for nerve injuries which informs prognosis and treatment, and a refined understanding and application of electrodiagnostic studies to guide patient selection. We provide indications for operative intervention based on this nerve injury classification and propose strategies best contoured for varying injury presentations at differing time points. Lastly, we discuss new developments in surgical techniques and approaches based on these advancements.

Nerve Autografts Versus Allografts for Mixed Motor/Sensory Nerve Reconstruction

Reconstruction of peripheral mixed motor/sensory nerves using autografts has remained the gold standard. Inconsistent and nonphysiologic results across nerve allograft studies, including successful and failed motor reinnervation, have limited the current clinical application of nerve allografts to noncritical small-diameter sensory nerve defects less than 3 cm. This scoping review aimed to compare outcomes in both basic science and clinical applications of autograft and allograft nerve reconstruction for mixed motor/sensory nerves.

Outcomes of Nerve Transfers in Peroneal Nerve Palsy

Background: The objective of this work is to: (i) evaluate the postoperative outcomes after lower extremity nerve transfer (LENT) in patients with peroneal nerve palsy, and (ii) evaluate the patient and surgical factors that best predict successful restoration of ankle dorsiflexion following nerve transfer. Methods: A retrospective cohort of prospectively collected data included all patients who underwent LENT (2010-2018). Two independent reviewers performed data collection. Primary outcome measures were: (i) clinically with British Medical Research Council (MRC) strength assessments, and (ii) electrodiagnostically with nascent motor unit potentials. Statistical analysis was performed using descriptive and nonparametric statistics. Results: Nine patients (56% male, mean age 38.3, range 18-57 years) underwent LENT surgery a mean of 4.3 months following injury (range 2.2-6.4 months). Mean follow-up was 15.6 months (range 9.1-28.2 months). Postoperatively, ankle dorsiflexion (P  =  .015) and ankle eversion (P  =  .041) increased significantly. After surgery, 44% achieved MRC 4, 33% obtained MRC 1 motor recovery, and 22% sustained MRC 0. A shorter time to surgery was associated with significantly better outcomes (P  =  .049). Conclusions: It appears that there is a bimodal distribution between responders and nonresponders to LENT for foot drop. Further research is required to elucidate patient and surgical factors that prognosticate success.

One-stage Neurorrhaphy and Posterior Transposition with Gastrocnemius Fascial Flap for Common Peroneal Nerve Injury: Preliminary Results

OBJECTIVE

Common peroneal nerve (CPN) injury is a frequently encountered lower extremity injury. Furthermore, several previous studies have demonstrated that patients who underwent direct suturing of the CPN following rupture experienced unfavorable postoperative prognoses. Therefore, we aimed to present a novel modified surgical approach for CPN rupture and assess the effectiveness of this technique in restoring lower limb functionality.

METHODS

In this retrospective observational study, we included patients with CPN rupture who underwent one-stage neurorrhaphy and posterior transposition combined with nerve wrapping using a gastrocnemius fascial flap for CPN rupture between January 2016 and December 2020. Lower limb function was evaluated using the lower extremity functional scale (LEFS) and British Medical Research Council (BMRC) grading system. We also assessed the influence of age, sex, duration of symptoms, mechanism of injury, and surgical modality on the postoperative recovery of lower extremity function using subgroup and regression analyses.

RESULTS

Thirty-seven patients (mean age = 35.76 ± 13.01 years) with at least 2 years of follow-up were included in the final analysis. The LEFS scores significantly improved after surgery at the last follow-up (p < 0.01). Moreover, 67.57% of the patients achieved good or excellent postoperative outcomes (BMRC: M3 or above). Results of the subgroup analysis and regression models suggested that patients who underwent direct suturing showed better recovery of lower extremity function than those who underwent nerve grafting.

CONCLUSION

One-stage neurorrhaphy and posterior transposition combined with nerve wrapping using a gastrocnemius fascial flap exhibited encouraging outcomes in restoring lower-limb function among patients with CPN rupture. This novel surgical technique is expected to be an effective method for treating CPN ruptures in the future.

Common Peroneal Nerve Injury Caused by a Wild Boar Attack

Wild boar-inflicted nerve injuries have been very rarely reported in the literature. A 62-year-old man was attacked by a wild boar in eastern Turkey and brought to the emergency department. He had 5 lacerations on the lower extremities and 2 on the posterior thoracic region. In addition to soft tissue lacerations, he sustained a complete laceration of the left common peroneal nerve with a foot drop. The common peroneal nerve was repaired primarily the day after the attack. The patient was discharged after a short hospital stay without any immediate complications; however, at the 10-mo follow-up, he still had a left foot drop.

Functional outcomes of different surgical treatments for common peroneal nerve injuries: a retrospective comparative study

BACKGROUND

This study aims to assess the recovery patterns and factors influencing outcomes in patients with common peroneal nerve (CPN) injury.

METHODS

This retrospective study included 45 patients with CPN injuries treated between 2009 and 2019 in Jing'an District Central Hospital. The surgical interventions were categorized into three groups: neurolysis (group A; n = 34 patients), nerve repair (group B; n = 5 patients) and tendon transfer (group C; n = 6 patients). Preoperative and postoperative sensorimotor functions were evaluated using the British Medical Research Council grading system. The outcome of measures included the numeric rating scale, walking ability, numbness and satisfaction. Receiver operating characteristic (ROC) curve analysis was utilized to determine the optimal time interval between injury and surgery for predicting postoperative foot dorsiflexion function, toe dorsiflexion function, and sensory function.

RESULTS

Surgical interventions led to improvements in foot dorsiflexion strength in all patient groups, enabling most to regain independent walking ability. Group A (underwent neurolysis) had significant sensory function restoration (P < 0.001), and three patients in Group B (underwent nerve repair) had sensory improvements. ROC analysis revealed that the optimal time interval for achieving M3 foot dorsiflexion recovery was 9.5 months, with an area under the curve (AUC) of 0.871 (95% CI = 0.661-1.000, P = 0.040). For M4 foot dorsiflexion recovery, the optimal cut-off was 5.5 months, with an AUC of 0.785 (95% CI = 0.575-0.995, P = 0.020). When using M3 toe dorsiflexion recovery or S4 sensory function recovery as the gold standard, the optimal cut-off remained at 5.5 months, with AUCs of 0.768 (95% CI = 0.582-0.953, P = 0.025) and 0.853 (95% CI = 0.693-1.000, P = 0.001), respectively.

CONCLUSIONS

Our study highlights the importance of early surgical intervention in CPN injury recovery, with optimal outcomes achieved when surgery is performed within 5.5 to 9.5 months post-injury. These findings provide guidance for clinicians in tailoring treatment plans to the specific characteristics and requirements of CPN injury patients.

Motor and sensory nerve transfers in the lower extremity: Systematic review of current reconstructive possibilities

BACKGROUND

Peripheral nerve injuries (PNI) are predominantly treated by anatomical repair or reconstruction with autologous nerve grafts or allografts. Motor nerve transfers for PNI in the upper extremity are well established; however, this technique is not yet widely used in the lower extremity. This literature review presents an overview of the current options and postoperative results for nerve transfers as a treatment for nerve injury in the lower extremity.

METHODS

A systematic search in PubMed and Embase databases was performed. Full-text English articles describing surgical procedures and postoperative outcomes of nerve transfers in the lower extremity were included. The primary outcome was postoperative muscle strength measured using the British Medical Research Council (MRC) scale, with MRC> 3 considered good and postoperative return of sensation reported according to the modified Highet classification.

RESULTS

A total of 36 articles for motor nerve transfer and 7 for sensory nerve transfer were included. Sixteen articles described motor nerve transfers for treating peroneal nerve injury, 17 for femoral nerve injury, 2 for tibial nerve injury, and one for obturator nerve injury. Transfers of multiple branches to restore deep peroneal nerve function led to a good outcome in 58% of patients and 43% when a single branch was used as a donor. The transfer of multiple branches for femoral nerve or obturator nerve repair was performed in all reported patients with a good outcome.

CONCLUSIONS

The transfer of motor nerves for the recovery of PNI is a feasible technique with relatively low risks and great benefits. The correct indication, timing, and surgical technique are essential for optimizing results.

Acellular Nerve Allografts in Major Peripheral Nerve Repairs: An Analysis of Cases Presenting With Limited Recovery

BACKGROUND

Acellular nerve allografts have been used successfully and with increasing frequency to reconstruct nerve injuries. As their use has been expanded to treat longer gap, larger diameter nerve injuries, some failed cases have been reported. We present the histomorphometry of 5 such cases illustrating these limitations and review the current literature of acellular nerve allografts.

METHODS

Between 2014 and 2019, 5 patients with iatrogenic nerve injuries to the median or ulnar nerve reconstructed with an AxoGen AVANCE nerve allograft at an outside hospital were treated in our center with allograft excision and alternative reconstruction. These patients had no clinical or electrophysiological evidence of recovery, and allograft specimens at the time of surgery were sent for histomorphological examination.

RESULTS

Three patients with a median and 2 with ulnar nerve injury were included. Histology demonstrated myelinated axons present in all proximal native nerve specimens. In 2 cases, axons failed to regenerate into the allograft and in 3 cases, axonal regeneration diminished or terminated within the allograft.

CONCLUSIONS

The reported cases demonstrate the importance of evaluating the length and the function of nerves undergoing acellular nerve allograft repair. In long length, large-diameter nerves, the use of acellular nerve allografts should be carefully considered.

Partial tibial nerve transfer for iatrogenic peroneal nerve palsy after endovenous laser ablation for varicose veins of the lower extremity: A case report

Postprocedural peroneal nerve palsy after endovenous laser ablation (EVLA) for varicose veins is rare and is associated with poor functional recovery. There have been no reports using tibial nerve transfer for iatrogenic peroneal nerve palsy after EVLA. Herein, we present a case with peroneal nerve injury after EVLA, which was successfully treated by partial tibial nerve transfer for the first time. A 75-year-old female presented with a right foot drop immediately after EVLA of the lesser saphenous vein. The ankle and toe dorsiflexion had a muscle grade of M0 on the British Medical Research Council muscle scale, without voluntary motor unit action potentials (MUAP) in the tibialis anterior (TA) muscle on the needle electromyography. Three months after the injury, surgical nerve exploration revealed a damaged common peroneal nerve with discoloration and scarring at the fibular head. Intraoperative deep peroneal nerve stimulation confirmed the absence of compound muscle action potentials in the TA. The best functioning motor fascicles of the tibial nerve were transferred to the deep peroneal main trunk involving motor branches of the TA, extensor digitorum longus, and extensor hallucis longus (EHL) through the interosseous membrane. The postoperative course was uneventful, with no complications. After 3 months of surgery, nascent MUAP appeared in the TA. After 24 months, the patient regained the TA and EHL muscle function and ambulation without an ankle-foot orthosis and tibial nerve deficits. Thus, our procedure may serve as an alternative to nerve grafting, tendon transfer, and orthoses for better management of the major neural complications associated with EVLA.

Conservative versus surgical treatment of foot drop in peroneal nerve entrapment: rationale and design of a prospective, multi-centre, randomized parallel-group controlled trial

BACKGROUND

High-quality evidence is lacking to support one treatment strategy over another in patients with foot drop due to peroneal nerve entrapment. This leads to strong variation in daily practice.

METHODS/DESIGN

The FOOTDROP (Follow-up and Outcome of Operative Treatment with Decompressive Release Of The Peroneal nerve) trial is a randomized, multi-centre study in which patients with peroneal nerve entrapment and persistent foot drop, despite initial conservative treatment, will be randomized 10 (± 4) weeks after onset between non-invasive treatment and surgical decompression. The primary endpoint is the difference in distance covered during the 6-min walk test between randomization and 9 months later. Time to recovery is the key secondary endpoint. Other secondary outcome measures encompass ankle dorsiflexion strength (MRC score and isometric dynamometry), gait assessment (10-m walk test, functional ambulation categories, Stanmore questionnaire), patient-reported outcome measures (EQ5D-5L), surgical complications, neurological deficits (sensory changes, motor scores for ankle eversion and hallux extension), health economic assessment (WPAI) and electrodiagnostic assessment.

DISCUSSION

The results of this randomized trial may elucidate the role of surgical decompression of the peroneal nerve and aid in clinical decision-making.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04695834. Registered on 4 January 2021.

Effects of regenerative peripheral nerve interface on dorsal root ganglia neurons following peripheral axotomy

Background

Long-term delayed reconstruction of injured peripheral nerves always results in poor recovery. One important reason is retrograde cell death among injured sensory neurons of dorsal root ganglia (DRG). A regenerative peripheral nerve interface (RPNI) was capable of generating new synaptogenesis between the proximal nerve stump and free muscle graft. Meanwhile, sensory receptors within the skeletal muscle can also be readily reinnervated by donor sensory axons, which allows the target muscles to become sources of sensory information for function reconstruction. To date, the effect of RPNI on injured sensory neurons is still unclear. Here, we aim to investigate the potential neuroprotective role of RPNI on sensory DRG neurons after sciatic axotomy in adult rats.

Materials and methods

The sciatic nerves of sixty rats were transected. The rats were randomly divided into three groups following this nerve injury: no treatment (control group, n = 20), nerve stump implantation inside a fully innervated muscle (NSM group, n = 20), or nerve stump implantation inside a free muscle graft (RPNI group, n = 20). At 8 weeks post-axotomy, ipsilateral L4 and L5 DRGs were harvested in each group. Toluidine blue staining was employed to quantify the neuronal densities in DRGs. The neuronal apoptosis index was quantified with TUNEL assay. Western blotting was applied to measure the expressions of Bax, Bcl-2, and neurotrophins (NTs) in ipsilateral DRGs.

Results

There were significantly higher densities of neurons in ipsilateral DRGs of RPNI group than NSM and control groups at 8 weeks post-axotomy (p < 0.01). Meanwhile, neuronal apoptosis index and the expressions of pro-apoptotic Bax within the ipsilateral DRGs were significantly lower in the RPNI group than those in the control and NSM groups (p < 0.05), while the opposite result was observed in the expression of pro-survival Bcl-2. Furthermore, the expressions of NGF, NT-3, BDNF, and GDNF were also upregulated in the ipsilateral DRGs in the RPNI group (p < 0.01).

Conclusion

The present results demonstrate that RPNI could prevent neuronal loss after peripheral axotomy. And the neuroprotection effect has a relationship with the upregulation of NTs in DRGs, such as NGF, NT-3, BDNF, and GDNF. These findings provide an effective therapy for neuroprotection in the delayed repair of the peripheral nerve injury.

A systematic review of nerve grafting, end-to-end repair, and nerve transfer for obturator nerve injuries

OBJECTIVE

Obturator nerve injury can occur as a complication of gynecologic surgeries, occurring most frequently in patients with endometriosis and genitourinary malignancies. The resulting injury causes paresthesia and major weakness in adduction and atrophy of the adductor group of lower extremity muscles. The objective of this study was to conduct a systematic review and meta-analysis of the effectiveness of end-to-end repair, nerve grafting, and nerve transfer in improving motor function in patients with obturator nerve injury.

METHODS

PubMed, Cochrane, Medline, and Embase libraries were searched from May 1994 to August 2020 according to the PRISMA guidelines for articles that present functional outcomes after obturator nerve injury in patients treated with nerve grafting, end-to-end repair, or nerve transfer.

RESULTS

A total of 25 patients from 22 studies were included in the study, 15 of whom were treated with end-to-end repair (60%), nine with nerve grafting (36%), and one with nerve transfer (4%). Of the 15 patients with transection data, two had incomplete (13%) and 13 had complete (87%) nerve transections. The patients underwent pelvic lymphadenectomy (n=24) and radical cystectomy (n=1) operations. The mean Medical Research Council (MRC) score was 2.95±1.7 immediately after treatment and 4.77±0.6 at the final follow-up. All patients achieved good outcomes (MRC ≥3) at the final follow-up. The mean MRC score for end-to-end repair (n=15), nerve grafting (n=9), and nerve transfer (n=1) was 4.8±0.6, 4.7±0.8, and 5, respectively. Patients with end-to-end repair had higher immediate post-operative strength than those treated with nerve grafting (p=0.03) and tended to achieve full functional recovery after shorter periods of time (rho=-0.65, p=0.049). Other parameters did not correlate with MRC.

CONCLUSION

End-to-end repair, nerve grafting, and nerve transfer are equally effective in restoring function in patients with obturator nerve injury. However, patients treated with end-to-end repair had higher immediate post-operative strength than those treated with nerve grafting.

Nerve Injuries in Total Knee Arthroplasty

Nerve injury is one of the potential complications of total knee arthroplasty. The extent of the injury includes motor and sensory dysfunction, either temporary or permanent. Although the consequences of nerve injury may be dramatic, the probability of occurrence during the course of primary knee arthroplasty is low, around 0.12% to 0.4%. Local dressing removal and knee flexion are imperative, and the initial investigations include ultrasound or MRI and nerve conduction studies. The extent of recovery depends on the type and severity of the initial nerve palsy; however, most patients are expected to have at least a partial recovery.

Surgical Treatment of Foot Drop: Patient Evaluation and Peripheral Nerve Treatment Options

Foot drop is a common clinical condition which may substantially impact physical function and health-related quality of life. The etiologies of foot drop are diverse and a detailed history and physical examination are essential in understanding the underlying pathophysiology and capacity for spontaneous recovery. Patients presenting with acute foot drop or those without significant spontaneous recovery of motor deficits may be candidates for surgical intervention. The timing, mechanism, and severity of neural injury resulting in foot drop influence the selection of the most appropriate peripheral nerve surgery, which may include direct nerve repair, neurolysis, nerve grafting, or nerve transfer.

Transfer of Soleus Muscular Branch of Tibial Nerve to Deep Fibular Nerve to Repair Foot Drop After Common Peroneal Nerve Injury: A Retrospective Study

Objective

Common peroneal nerve (CPN) injury that leads to foot drop is difficult to manage and treat. We present a new strategy for management of foot drop after CPN injury. The soleus muscular branch of the tibial nerve is directly transferred to the deep fibular nerve, providing partial restoration of motor function.

Methods

We retrospectively reviewed eight patients treated for CPN injury between 2017 and 2019. The soleus muscular branch of the tibial nerve was transferred to the deep fibular nerve to repair foot drop. Electrophysiology was conducted, and motor function was assessed. Motor function was evaluated by measuring leg muscle strength during ankle dorsiflexion using the British Medical Research Council (BMRC) grading system and electromyography (EMG).

Results

In 10–15 months postoperatively, EMG revealed newly appearing electrical potentials in the tibialis anterior, extensor hallucis longus, and extensor toe longus muscle (N = 7). Two patients achieved BMRC grade of M4 for ankle dorsiflexion, 2 patients achieved M3, 1 patient achieved M2, and 2 patients achieved M1. Four patients showed good functional recovery after surgery and could walk and participate in activities without ankle-foot orthotics.

Conclusion

Surgical transfer of the soleus muscular branch of the tibial nerve to the deep fibular nerve after CPN injury provides variable improvements in ankle dorsiflexion strength. Despite variable strength gains, 50% of patients achieved BMRC M3 or greater motor recovery, which enabled them to walk without assistive devices.

Posterior Tibial Tendon Transfer for the Correction of Drop Foot

BACKGROUND

Drop foot is a crippling condition that often requires surgical intervention to restore functional dorsiflexion. Although transfer of the posterior tibial (PT) tendon has been well described for the treatment of drop foot, there is no consensus on whether tendon transfers affecting the ankle joint sufficiently restore functional status for daily activities. In addition, most studies have focused on drop foot caused by peripheral nerve disorders. The purpose of this study was to evaluate the functional outcomes and patient satisfaction following PT tendon transfer for the correction of drop foot resulting from both peripheral and central neurologic causes.

METHODS

Patients with drop foot who underwent a PT tendon transfer were followed for a minimum of 1 year and investigated retrospectively. Outcome measures included the American Orthopaedic Foot & Ankle Society ankle and hindfoot scoring system, a patient satisfaction questionnaire, postoperative ankle range of motion, and postoperative ambulatory status.

RESULTS

We evaluated 15 feet in 14 patients at a median follow-up of 50 months. The median postoperative American Orthopaedic Foot & Ankle Society ankle and hindfoot score was 85.0. Thirteen patients (92.9%) reported that they would undergo the procedure again. The median postoperative passive ankle dorsiflexion was 5.0°, and the median postoperative passive ankle plantarflexion was 30.0°. Thirteen patients (92.9%) were able to ambulate postoperatively. Ten (71.4%) ambulated without the use of an ankle-foot orthosis (AFO), and three (21.4%) ambulated with the use of an AFO. Overall, orthoses were able to be discontinued in 73.3% of the cases.

CONCLUSIONS

Our results suggest that the PT tendon transfer is an effective procedure for the treatment of drop foot that can improve the patient's functional status and ability to ambulate. The majority of patients were able to discontinue the use of their AFO postoperatively.

Outcomes of Tibial Nerve Repair and Transfer: A Structured Evidence-Based Systematic Review and Meta-Analysis

Although nerve transfer and repair are well-established for treatment of nerve injury in the upper extremity, there are no established parameters for when or which treatment modalities to utilize for tibial nerve injuries. The objective of our study is to conduct a systematic review of the effectiveness of end-to-end repair, neurolysis, nerve grafting, and nerve transfer in improving motor function after tibial nerve injury. PubMed, Cochrane, Medline, and Embase libraries were queried according to the PRISMA guidelines for articles that present functional outcomes after tibial nerve injury in humans treated with nerve transfer or repair. The final selection included Nineteen studies with 677 patients treated with neurolysis (373), grafting (178), end-to-end repair (90), and nerve transfer (30), from 1985 to 2018. The mean age of all patients was 27.0 ± 10.8 years, with a mean preoperative interval of 7.4 ± 10.5 months, and follow-up period of 82.9 ± 25.4 months. The mean graft repair length for nerve transfer and grafting patients was 10.0 ± 5.8 cm, and the most common donor nerve was the sural nerve. The most common mechanism of injury was gunshot wound, and the mean MRC of all patients was 3.7 ± 0.6. Good outcomes were defined as MRC ≥ 3. End-to-end repair treatment had the greatest number of good outcomes, followed by neurolysis. Patients with preoperative intervals less than 7 months were more likely to have good outcomes than those greater than 7 months. Patients with sport injuries had the highest percentage of good outcomes in contrast to patients with transections and who were in MVAs. We found no statistically significant difference in good outcomes between the use of sural and peroneal donor nerve grafts, nor between age, graft length, and MRC score.

Evidence in peroneal nerve entrapment: A scoping review

BACKGROUND AND PURPOSE

Daily management of patients with foot drop due to peroneal nerve entrapment varies between a purely conservative treatment and early surgery, with no high-quality evidence to guide current practice. Electrodiagnostic (EDX) prognostic features and the value of imaging in establishing and supplementing the diagnosis have not been clearly established.

METHODS

We performed a literature search in the online databases MEDLINE, Embase, and the Cochrane Library. Of the 42 unique articles meeting the eligibility criteria, 10 discussed diagnostic performance of imaging, 11 reported EDX limits for abnormal values and/or the value of EDX in prognostication, and 26 focused on treatment outcome.

RESULTS

Studies report high sensitivity and specificity of both ultrasound (varying respectively from 47.1% to 91% and from 53% to 100%) and magnetic resonance imaging (MRI; varying respectively from 31% to 100% and from 73% to 100%). One comparative trial favoured ultrasound over MRI. Variable criteria for a conduction block (>20%-≥50) were reported. A motor conduction block and any baseline compound motor action potential response were identified as predictors of good outcome. Based predominantly on case series, the percentage of patients with good outcome ranged 0%-100% after conservative treatment and 40%-100% after neurolysis. No study compared both treatments.

CONCLUSIONS

Ultrasound and MRI have good accuracy, and introducing imaging in the standard diagnostic workup should be considered. Further research should focus on the role of EDX in prognostication. No recommendation on the optimal treatment strategy of peroneal nerve entrapment can be made, warranting future randomized controlled trials.

Ski- and snowboard related open peroneal nerve injury: A 20-year retrospective case series study

Introduction

Traumatic peroneal nerve injury (PNI) caused by ski or snowboard edges is a severe but scarcely reported accident.

Methods

In a 20-year retrospective study, all skiers and snowboarders with this injury treated surgically at the Department of Plastic, Reconstructive and Aesthetic Surgery at the Medical University of Innsbruck, Austria, were included, covering a period from 1999/2000 to 2018/2019.

Results

In total, 34 patients were included in this study (30 males (88.2%) and 4 (11.8%) females). Of these 34 injured skiers or snowboarders, 33 (97.1%) were recreational athletes and Non-Austrian citizens, and 21 (61.8%) patients sustained accidental injuries without collision. All of the injuries under investigation, i.e., open lacerations, most often with complete transection, were the patients’ main injuries. Surgery was performed with direct coaptation in 24 patients (70.6%), and with a suralis nerve graft in the other 10 patients (29.4%).

Conclusion

Traumatic laceration of the peroneal nerve at the knee level by sharp ski or snowboard edges is a rare but severe injury. Causes for this injury may be multifactorial. Recommendations to reduce the risk of such an injury may follow general instructions and warnings to skiers and snowboarders regarding equipment, familiarity with the region, as well as appropriate skills and training.

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In accidents of skiers and snowboarders traumatic laceration of the peroneal nerve is a severe, but rare injury.

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This injury type is rarely reported.

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The injuries are caused by the sharp edges of modern skies or snowboards and require urgent microsurgical intervention.

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Our 20 years study shows that this injury type primarily affects recreational athletes and guest skiers.

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Current equipment, e.g. ski trousers do not protect the affected region on the lateral side of the knee.

The Addition of a Nerve Transfer to the Treatment of Peroneal Neuropathy Secondary to Intraneural Ganglion: Case Series

ABSTRACT

Peroneal intraneural ganglia are rare, and their management is controversial. Presently, the accepted treatment of intraneural ganglia is decompression and ligation of the articular nerve branch. Although this treatment prevents recurrence of the ganglia, the resultant motor deficit of foot drop in the case of intraneural peroneal ganglia is unsatisfying. Foot drop is classically treated with splinting or tendon transfers to the foot. We have recently published a case report of a peroneal intraneural ganglion treated by transferring a motor nerve branch of flexor hallucis longus into a nerve branch of tibialis anterior muscle in addition to articular nerve branch ligation and decompression of the intraneural ganglion to restore the patient's ability to dorsiflex. We have since performed this procedure on 4 additional patients with appropriate follow-up. Depending on the initial onset of foot drop and time to surgery, nerve transfer from flexor hallucis longus to anterior tibialis nerve branch may be considered as an adjunct to decompression and articular nerve branch ligation for the treatment of symptomatic peroneal intraneural ganglion.

Current Concepts Review: Common Peroneal Nerve Palsy After Knee Dislocations

Dislocation of the native knee represents a challenging injury, further complicated by the high rate of concurrent injury to the common peroneal nerve (CPN). Initial management of this injury requires a thorough neurovascular examination, given the prevalence of popliteal artery injury and limb-threatening ischemia. Further management of a knee dislocation with associated CPN palsy requires coordinated care involving the sports surgeon for ligamentous knee reconstruction and the peripheral nerve surgeon for staged or concurrent peroneal nerve decompression and/or reconstruction. Finally, the foot and ankle surgeon is often required to manage a foot drop with a distal tendon transfer to restore foot dorsiflexion. For instance, the Bridle Procedure-a modification of the anterior transfer of the posterior tibialis muscle, under the extensor retinaculum, with tri-tendon anastomosis to the anterior tibial and peroneus longus tendons at the anterior ankle-can successfully return patients to brace-free ambulation and athletic function following CPN palsy. Cross-discipline coordination and collaboration is essential to ensure appropriate timing of operative interventions and ensure maintenance of passive dorsiflexion prior to tendon transfer.

Common Peroneal Nerve Injury Related to Small Saphenous Vein Surgery: Report of 2 Cases and Review of the Literature

Although iatrogenic damage is less often involved, deep nerve injuries are reported especially as a result of small saphenous vein (SSV) dissection. Complete or partial division of the common peroneal nerve (CPN) during varicose vein operations causes substantial and serious disability. Most CPN injuries recover spontaneously; nonetheless, some require nerve surgery. Treatment depends on the nature of CPN injury. This report chronicles 2 instances of CPN injury after SSV surgery, addressing treatment strategies and therapeutic gains. The pertinent literature is also reviewed.

Prognostic factors in patients who underwent surgery for common peroneal nerve injury: a nest case-control study

Background

Common peroneal nerve (CPN) injury is one of the most common nerve injuries in the lower extremities and the motor functional recovery of injured common peroneal nerve (CPN) was often unsatisfactory, the mechanism of which is still controversial. The purpose of this retrospective study was to determine the prognostic factors in patients who underwent surgery for CPN injury and provide a tool for clinicians to assess the patients’ prognosis.

Methods

This is a retrospective cohort study of all patients who underwent neural exploration for injured CPN from 2009 to 2019. A total of 387 patients with postoperative follow-up more than 12 months were included in the final analysis. We used univariate logistics regression analyses to explore explanatory variables which were associated with recovery of neurological function. By applying multivariable logistic regression analysis, we determined variables incorporated into clinical prediction model, developed a nomogram by the selected variables, and then assessed discrimination of the model by the area under the curve (AUC) of the receiver operating characteristic (ROC) curve.

Results

The case group included 67 patients and the control group 320 patients. Multivariate logistic regression analysis showed that area (urban vs rural, OR = 3.35), occupation(“blue trouser” worker vs “white-trouser” worker, OR = 4.39), diabetes (OR = 11.68), cardiovascular disease (OR = 51.35), knee joint dislocation (OR = 14.91), proximal fibula fracture (OR = 3.32), tibial plateau fracture (OR = 9.21), vascular injury (OR = 5.37) and hip arthroplasty (OR = 75.96) injury increased the risk of poor motor functional recovery of injured CPN, while high preoperative muscle strength (OR = 0.18) and postoperative knee joint immobilization (OR = 0.11) decreased this risk of injured CPN. AUC of the nomogram was 0.904 and 95% CI was 0.863–0.946.

Conclusions

Area, occupation, diabetes, cardiovascular disease, knee joint dislocation, proximal fibula fracture, tibial plateau fracture, vascular injury and hip arthroplasty injury are independent risk factors of motor functional recovery of injured CPN, while high preoperative muscle strength and postoperative knee joint immobilization are protective factors of motor functional recovery of injured CPN. The prediction nomogram can provide a tool for clinicians to assess the prognosis of injured CPN.

Fibular Nerve Repair by Lateral Sural Cutaneous Nerve Graft: Anatomic Feasibility Study and Clinical Results

OBJECTIVE

The common fibular nerve (CFN) is the most frequently injured nerve in the lower limbs. Surgical management is necessary in approximately two thirds of patients and includes neurolysis, suture, graft repair, or nerve transfer. The distal sural nerve is the preferred donor for grafting, but it is not without complications and requires a second incision. We sought to study the surgical anatomy of the lateral sural cutaneous nerve (LSCN) with the aim of repairing CFN injuries through the same incision and as a potential source for grafting in other nerve injuries.

METHODS

The popliteal fossa was dissected in 11 lower limbs of embalmed cadavers to study LSCN variations. Four patients with CFN injuries then underwent surgical repair by LSCN grafting using the same surgical approach.

RESULTS

At the medial margin of the biceps femoris, the LSCN emerged from the CFN approximately 8.15 cm above the fibular head. The LSCN ran longitudinally to the long axis of the popliteal fossa, with an average of 3.2 cm medial to the fibular head. The mean LSCN length and diameter were 9.61 cm and 3.6 mm, respectively. The LSCN could be harvested in all patients for grafting. The mean graft length was 4.4 cm. Motor function was consistently recovered for foot eversion but was recovered to a lesser extent for dorsiflexion and toe extension. All patients recovered sensitive function (75% of S3). Hypoesthesia was recognized at the calf.

CONCLUSIONS

LSCN harvest is a viable alternative for nerve grafting, especially for repairing short CFN injuries, thereby avoiding the need for a second incision.

Partial tibial nerve transfer for foot drop from deep peroneal palsy: Lessons from three pediatric cases

Peroneal nerve palsy with resultant foot drop has significant impacts on gait and quality of life. Traditional management includes ankle-foot-orthosis, tendon transfer, and arthrodesis-each with certain disadvantages. While nerve transfers for peroneal nerve injury have been reported in adults, with variable results, they have not been described in the pediatric population. We report the use of partial tibial nerve transfer for foot drop from deep peroneal nerve palsy in three pediatric patients. The first sustained a partial common peroneal nerve laceration and underwent transfer of a single tibial nerve branch to deep peroneal nerve 7 months after injury. Robust extensor hallucis longus and extensor digitorum longus reinnervation was obtained without satisfactory tibialis anterior function. The next patient sustained a thigh laceration with partial sciatic nerve injury and underwent transfer of two tibial nerve branches directly to the tibialis anterior component of deep peroneal nerve 9 months after injury. The final patient sustained a blast injury to the posterior knee and similarly underwent a double fascicular transfer directly to tibialis anterior 4 months after injury. The latter two patients obtained sufficient strength (MRC 4-5) at 1 year to discontinue orthosis. In all patients, we used flexor hallucis longus and/or flexor digitorum longus branches as donors without postoperative loss of toe flexion. Overall, our experience suggests that early double fascicular transfer to an isolated tibialis anterior target, combined with decompression, could produce robust innervation. Further study and collaboration are needed to devise new ways to treat lower extremity nerve palsies.

A simple test to assist with the diagnosis of common fibular nerve entrapment and predict outcomes of surgical decompression

BACKGROUND

Common fibular (peroneal) nerve (CFN) entrapment is the most frequent nerve entrapment in the lower extremity. It can cause pain, sensory abnormalities, and reduced ability to dorsiflex the foot or a drop foot. A simple test to assist with diagnosis of CFN entrapment is described as an adjunctive clinical tool for the diagnosis of CFN entrapment and also as a predictor of successful surgical decompression of a CFN entrapment.

METHODS

The test, a lidocaine injection into the peroneus longus muscle at the site of a common fibular nerve entrapment, was studied retrospectively in 21 patients who presented with a clinical suspicion of CFN entrapment. Patients ages ranged from 17 to 71 (mean 48.5).

RESULTS

The lidocaine injection test (LIT) was positive in 19 patients, and of these, 17 underwent surgical decompression and subsequently experienced improved ability to dorsiflex their foot and reduced sensory abnormalities.

CONCLUSION

The LIT is a simple, safe adjunctive test to help diagnose and also predict a successful outcome of surgical decompression of a CFN entrapment. The proposed mechanism of action of the LIT could lead to new, non-surgical treatments for CFN entrapment.

Differential gene and protein expression in gastrocnemius and tibialis anterior muscle following tibial and peroneal nerve injury in rats

Peripheral nerve injury is encountered quite commonly in the clinic, and treatment results are often not satisfactory. Therefore, promoting nerve regeneration and functional recovery is a primary goal of neuroscience research. Recovery of corresponding target muscle can differ following peripheral nerve injury, but the reasons are unknown. Herein, we investigated differential gene and protein expression in gastrocnemius and tibialis anterior muscle following tibial and common peroneal nerve injury using RNA sequencing and proteomics approaches, and analysed the results by bioinformatics. In total, 1794, 1765, 1656 and 2006 differential genes and 398, 400, 959 and 472 differential proteins were identified in gastrocnemius and tibialis anterior muscles at 1, 7, 14 and 21 days after surgery, related to activation of 51 signalling pathways. Differential expression of these genes and proteins may contribute to the degree of recovery of target organs following peripheral nerve injury. The findings provide a foundation for investigating regeneration mechanisms following peripheral nerve injury.

Translocation of the soleus muscular branch of the tibial nerve to repair high common peroneal nerve injury

BACKGROUND

This study was performed to evaluate the clinical effect of translocating the soleus muscular branch of the tibial nerve to repair the deep peroneal nerve.

METHODS

Eight patients were treated for high common peroneal nerve injury. The deep peroneal nerve was separated out from the common peroneal nerve if no injury occurred upon opening the epineurium of the common peroneal nerve. The soleus muscular branch of the tibial nerve was then translocated to the deep peroneal nerve.

RESULTS

The average follow-up duration was 21.75 months. Electromyography revealed newly appearing electric potentials in the tibialis anterior, extensor hallucis longus, and extensor toe longus muscle at 8 to 10 months postoperatively. Four patients showed good functional recovery after surgery; functional recovery was poor in other patients.

CONCLUSIONS

Translocation of the soleus muscle branch is a feasible method to treat high common peroneal nerve injuries. A full understanding of the indications for this operation is required.

Differential gene and protein expression between rat tibial nerve and common peroneal nerve during Wallerian degeneration

Wallerian degeneration and nerve regeneration after injury are complex processes involving many genes, proteins and cytokines. After different peripheral nerve injuries the regeneration rate can differ. Whether this is caused by differential expression of genes and proteins during Wallerian degeneration remains unclear. The right tibial nerve and the common peroneal nerve of the same rat were exposed and completely cut through and then sutured in the same horizontal plane. On days 1, 7, 14, and 21 after surgery, 1–2 cm of nerve tissue distal to the suture site was dissected out from the tibial and common peroneal nerves. The differences in gene and protein expression during Wallerian degeneration of the injured nerves were then studied by RNA sequencing and proteomic techniques. In the tibial and common peroneal nerves, there were 1718, 1374, 1187, and 2195 differentially expressed genes, and 477, 447, 619, and 495 differentially expressed proteins on days 1, 7, 14, and 21 after surgery, respectively. Forty-seven pathways were activated during Wallerian degeneration. Three genes showing significant differential expression by RNA sequencing (Hoxd4, Lpcat4 and Tbx1) were assayed by real-time quantitative polymerase chain reaction. RNA sequencing and real-time quantitative polymerase chain reaction results were consistent. Our findings showed that expression of genes and proteins in injured tibial and the common peroneal nerves were significantly different during Wallerian degeneration at different time points. This suggests that the biological processes during Wallerian degeneration are different in different peripheral nerves after injury. The procedure was approved by the Animal Experimental Ethics Committee of the Second Military Medical University, China (approval No. CZ20160218) on February 18, 2016.

Short- and long-term results of common peroneal nerve injuries treated by neurolysis, direct suture or nerve graft

INTRODUCTION

Damage to the common peroneal nerve is the most frequent nerve injury in lower limb traumas. Our objective was to assess the motor and sensory recovery levels and the functional outcomes after remedial surgery for common peroneal nerve trauma, through either neurolysis, direct suture or nerve graft.

METHODS

This is a transversal, observational study of a monocentric cohort of 20 patients who underwent surgery between January 2004 and June 2016, which included 16 men and 4 women whose median age was 35 ± 11 years. We assessed the level of sensory and motor nerve recovery and the Kitaoka score. Nine patients benefited from neurolysis, 5 had direct sutures, and 6 received a nerve graft.

RESULTS

With 48 months' average follow-up, 7 out of 9 patients underwent neurolysis and 4 out of 5 with direct sutures had good motor recovery (≥ M4), but none for the grafts. Sensory recovery (≥ S3) was satisfactory in 7 out of 9 cases in the neurolysis group, 3 out of 5 in the direct suture group, and 3 out of 6 in the nerve graft group. The average Kitaoka score was 83.7 ± 11.5 for the neurolysis group, 86.8 ± 16 for the direct suture group, and 73 ± 14 for the graft group.

CONCLUSION

Surgical treatment by neurolysis and direct suture yields good results with a motor recovery ratio nearing 80%. When a nerve graft becomes necessary, recovery is poor and resorting to palliative techniques in the shorter run is a strategy which should be evaluated.

Peroneal Nerve Repair of a 9 Year Old: Return of Motor Function after 2 Years

Major factors that influence functional nerve recovery, postrepair, are length of the nerve defect, type of injury, operative technique, time until treatment, and age of the patient. We present a severe motor nerve defect in a complicated peroneal nerve injury in a 9-year-old that showed functional return after a delayed period of 23 months with sural nerve cable grafting. This case revealed the increased resiliency and regenerative capacity of motor end plates in young patients. In conclusion, autograft for a deep peroneal nerve repair, by means of sural nerve graft, proved to be an acceptable option in children.

Open surgical implantation of a viable cryopreserved placental membrane after decompression and neurolysis of common peroneal nerve: a case series

Background

The purpose of this study is to report on the rehabilitative outcomes associated with common peroneal nerve (CPN) decompression and neurolysis revision when performed with open surgical implantation of a viable cryopreserved placental membrane (vCPM).

Methods

Seven patients who underwent secondary CPN decompression and neurolysis with open surgical implantation of a viable cryopreserved placental membrane (vCPM) after previously failed surgery without vCPM utilization were identified through a retrospective medical record review and outcomes were analyzed. Primary mechanism of injury, severity of symptoms at time of referral, pre-operative and post-operative evaluations on edema with ultrasound, Medical Research Council (MRC) scale for motor strength, range of motion, nerve conduction velocity (NCV), and electromyography (EMG) were analyzed.

Results

Five patients (71.4%) achieved full recovery of motor function MRC grade 5/5, and the remaining two patients achieved MRC grade 4/5. At the 7-month follow-up visit, NCV tests indicated improved conduction velocity and normal amplitude for all 7 patients, and all patients demonstrated proper gait pattern with a return to normal activities of daily living. There were no vCPM-related adverse events.

Conclusions

The use of vCPM wrap as an adjunct to surgical repairs of CPN injuries may contribute to positive clinical outcomes.

Autologous transplantation with fewer fibers repairs large peripheral nerve defects

Peripheral nerve injury is a serious disease and its repair is challenging. A cable-style autologous graft is the gold standard for repairing long peripheral nerve defects; however, ensuring that the minimum number of transplanted nerve attains maximum therapeutic effect remains poorly understood. In this study, a rat model of common peroneal nerve defect was established by resecting a 10-mm long right common peroneal nerve. Rats receiving transplantation of the common peroneal nerve in situ were designated as the in situ graft group. Ipsilateral sural nerves (10–30 mm long) were resected to establish the one sural nerve graft group, two sural nerves cable-style nerve graft group and three sural nerves cable-style nerve graft group. Each bundle of the peroneal nerve was 10 mm long. To reduce the barrier effect due to invasion by surrounding tissue and connective-tissue overgrowth between neural stumps, small gap sleeve suture was used in both proximal and distal terminals to allow repair of the injured common peroneal nerve. At three months postoperatively, recovery of nerve function and morphology was observed using osmium tetroxide staining and functional detection. The results showed that the number of regenerated nerve fibers, common peroneal nerve function index, motor nerve conduction velocity, recovery of myodynamia, and wet weight ratios of tibialis anterior muscle were not significantly different among the one sural nerve graft group, two sural nerves cable-style nerve graft group, and three sural nerves cable-style nerve graft group. These data suggest that the repair effect achieved using one sural nerve graft with a lower number of nerve fibers is the same as that achieved using the two sural nerves cable-style nerve graft and three sural nerves cable-style nerve graft. This indicates that according to the ‘multiple amplification’ phenomenon, one small nerve graft can provide a good therapeutic effect for a large peripheral nerve defect.

Surgical outcome of foot drop caused by common peroneal nerve injuries; is the glass half full or half empty?

BACKGROUND

Foot drop is a gait abnormality with various etiologies. The Common Peroneal Nerve (CPN) is one of the most frequently injured peripheral nerves. CPN deficit leads to foot drop. Most CPN injuries recover spontaneously; nonetheless, some require nerve surgery. The present study set out to assess the surgical outcomes of foot drop following CPN injuries.

METHOD

Surgical outcomes were reviewed in 36 subjects with foot drop caused by CPN injuries, undergoing surgical nerve exploration. The CPN injuries were confirmed by physical examination, Magnetic Resonance Imaging (MRI) and electrodiagnostic findings.

RESULTS

Subsequent to surgery, a significant improvement was seen in the motor recovery of the subjects. Interestingly, no significant difference in the recovery was found between neurolysis and nerve repair (direct repair and nerve grafting). There was no significant association between the age and the functional recovery. Gender was not associated with the functional recovery. No significant difference was seen in the recovery between thigh-level and knee-level CPN divisions.

CONCLUSIONS

The findings from the present study suggest that nerve surgery can yield beneficial results in the recovery of foot drop following CPN injuries. In addition, the surgical outcome of neurolysis in the treatment of CPN injuries can be similar to that of the nerve repair (direct repair or nerve grafting). This may show the value of nerve repair, which was comparable to neurolysis in the treatment of CPN injuries.

Peroneal Nerve Palsy: Evaluation and Management

Peroneal nerve palsy is the most common entrapment neuropathy of the lower extremity. Numerous etiologies have been identified; however, compression remains the most common cause. Although injury to the nerve may occur anywhere along its course from the sciatic origin to the terminal branches in the foot and ankle, the most common site of compressive pathology is at the level of the fibular head. The most common presentation is acute complete or partial foot drop. Associated numbness in the foot or leg may be present, as well. Neurodiagnostic studies may be helpful for identifying the site of a lesion and determining the appropriate treatment and prognosis. Management varies based on the etiology or site of compression. Many patients benefit from nonsurgical measures, including activity modification, bracing, physical therapy, and medication. Surgical decompression should be considered for refractory cases and those with compressive masses, acute lacerations, or severe conduction changes. Results of surgical decompression are typically favorable. Tendon and nerve transfers can be used in the setting of failed decompression or for patients with a poor prognosis for nerve recovery.