Outcomes of nerve reconstruction for radial nerve injuries based on the level of injury in 244 operative cases

Effects of exosomes from mesenchymal stem cells on functional recovery of a patient with total radial nerve injury: A pilot study

BACKGROUND

Peripheral nerve injury can result in significant clinical complications that have uncertain prognoses. Currently, there is a lack of effective pharmacological interventions for nerve damage, despite the existence of several small compounds, peptides, hormones, and growth factors that have been suggested as potential enhancers of neuron regeneration. Despite the objective of achieving full functional restoration by surgical intervention, the persistent challenge of inadequate functional recovery remains a significant concern in the context of peripheral nerve injuries.

AIM

To examine the impact of exosomes on the process of functional recovery following a complete radial nerve damage.

METHODS

A male individual, aged 24, who is right-hand dominant and an immigrant, arrived with an injury caused by a knife assault. The cut is located on the left arm, specifically below the elbow. The neurological examination and electrodiagnostic testing reveal evidence of left radial nerve damage. The sural autograft was utilized for repair, followed by the application of 1 mL of mesenchymal stem cell-derived exosome, comprising 5 billion microvesicles. This exosome was split into four equal volumes of 0.25 mL each and delivered microsurgically to both the proximal and distal stumps using the subepineural pathway. The patient was subjected to a period of 180 d during which they had neurological examination and electrodiagnostic testing.

RESULTS

The duration of the patient's follow-up period was 180 d. An increasing Tinel's sign and sensory-motor recovery were detected even at the 10th wk following nerve grafting. Upon the conclusion of the 6-mo post-treatment period, an evaluation was conducted to measure the extent of improvement in motor and sensory functions of the nerve. This assessment was based on the British Medical Research Council scale and the Mackinnon-Dellon scale. The results indicated that the level of improvement in motor function was classified as M5, denoting an excellent outcome. Additionally, the level of improvement in sensory function was classified as S3+, indicating a good outcome. It is noteworthy that these assessments were conducted in the absence of physical therapy. At the 10th wk post-injury, despite the persistence of substantial axonal damage, the nerve exhibited indications of nerve re-innervation as evidenced by control electromyography (EMG). In contrast to the preceding. EMG analysis revealed a significant electrophysiological enhancement in the EMG conducted at the 6th-mo follow-up, indicating ongoing regeneration.

CONCLUSION

Enhanced comprehension of the neurobiological ramifications associated with peripheral nerve damage, as well as the experimental and therapy approaches delineated in this investigation, holds the potential to catalyze future clinical progress.

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.

Outcomes and prognostic factors for nerve grafting following high radial nerve injury

In this study, we examined the prognostic factors affecting outcomes following nerve grafting in high radial nerve injuries. Thirty-three patients with radial nerve injuries at a level distal to the first branch to the triceps and proximal to the posterior interosseous nerve were retrospectively studied. After a follow-up of at least 1 year, 24 patients (73%) obtained M3+ wrist extension, 16 (48%) obtained M3+ finger extension and only ten (30%) obtained M3+ thumb extension. Univariate, multivariate and receiver operating characteristic analyses showed that a delay in the repair of less than 6 months, a defect length of less than 5 cm or when grafted with three or more donor nerve cables achieved better recovery. Number of cables used was related to muscle strength recovery but not time to reinnervation. Nerve grafting for high radial nerve injury achieved relatively good wrist extension but poor thumb extension and is affected by certain prognostic factors.       Level of evidence: IV.

Traumatic peripheral nerve injuries: a classification proposal

BACKGROUND

Peripheral nerve injuries (PNIs) include several conditions in which one or more peripheral nerves are damaged. Trauma is one of the most common causes of PNIs and young people are particularly affected. They have a significant impact on patients' quality of life and on the healthcare system, while timing and type of surgical treatment are of the utmost importance to guarantee the most favorable functional recovery. To date, several different classifications of PNIs have been proposed, most of them focusing on just one or few aspects of these complex conditions, such as type of injury, anatomic situation, or prognostic factors. Current classifications do not enable us to have a complete view of this pathology, which includes diagnosis, treatment choice, and possible outcomes. This fragmentation sometimes leads to an ambiguous definition of PNIs and the impossibility of exchanging crucial information between different physicians and healthcare structures, which can create confusion in the choice of therapeutic strategies and timing of surgery.

MATERIALS

The authors retrospectively analyzed a group of 24 patients treated in their center and applied a new classification for PNI injuries. They chose (a) five injury-related factors, namely nerve involved, lesion site, nerve type (whether motor, sensory or mixed), surrounding tissues (whether soft tissues were involved or not), and lesion type-whether partial/in continuity or complete. An alphanumeric code was applied to each of these classes, and (b) four prognostic codes, related to age, timing, techniques, and comorbidities.

RESULTS

An alphanumeric code was produced, similar to that used in the AO classification of fractures.

CONCLUSIONS

The authors propose this novel classification for PNIs, with the main advantage to allow physicians to easily understand the characteristics of nerve lesions, severity, possibility of spontaneous recovery, onset of early complications, need for surgical treatment, and the best surgical approach.

LEVEL OF EVIDENCE

according to the Oxford 2011 level of evidence, level 2.

Optimal timing of needle electromyography to diagnose lesion severity in traumatic radial nerve injury

INTRODUCTION/AIMS

In patients with traumatic radial nerve injury (RNI), the chance of spontaneous recovery must be balanced against the benefits of early surgical reconstruction. We aimed to explore the time-specific value of needle electromyography (NEMG) to diagnose nerve lesion severity.

METHODS

In this retrospective diagnostic accuracy study at Leiden Nerve Center, patients at least 12 years of age with RNI caused by fractures or fracture treatment were included. The sensitivity and specificity of the patients' first NEMG examination were assessed, stratified by the timing after the nerve injury. The absence of motor unit potentials (MUPs) in muscles distal to the nerve lesion was considered a positive test result. Lesion severity was dichotomized to moderate injury (spontaneous Medical Research Council grade ≥3 recovery) or severe injury (poor spontaneous recovery or surgical confirmation of a mainly neurotmetic lesion).

RESULTS

Ninety-five patients were included in our study. The sensitivity of NEMG to detect severe RNI was 75.0% (3 of 4) in the fourth, 66.7% (2 of 3) in the fifth, and 66.7% (2 of 3) in the sixth month after the nerve injury. The specificity in the first to the sixth month was 0.0% (0 of 1), 50.0% (2 of 4), 77.3% (17 of 22), 95.5% (21 of 22), 95.8% (23 of 24), and 100.0% (12 of 12), respectively.

DISCUSSION

The specificity of NEMG is higher than 95% and therefore clinically relevant from the fourth month after the nerve injury onward. Absence of MUPs at this time can be considered an indication to plan nerve exploration. Moreover, the presence of MUPs on NEMG does not completely exclude the necessity for surgical reconstruction.

Etiological and epidemiological characteristics of surgically treated radial nerve lesions: A 20-year single-center experience

Introduction

Radial nerve lesions present a clinical entity that may lead to disability, psychological distress, and job loss, and thus requires great attention. Knowledge of the etiology and exact mechanism of the nerve impairment is of great importance for appropriate management of these patients, and there are only a few papers that focused on these features in patients with surgically treated radial nerve lesions. The lack of studies presenting the etiology and injury mechanisms of surgically treated radial nerve lesions may be due to a relatively small number of specialized referral centers, dispersion to low-flow centers, and a greater focus on the surgical treatment outcomes.

Aim

The aim of this study was to describe the etiological and epidemiological characteristics of patients with surgically treated radial nerve lesions of various origins.

Methods

This retrospective study evaluated 147 consecutive patients with radial nerve lesion, treated in the department during the last 20 years, from January 1, 2001, until December 31, 2020.

Results

The majority of patients belonged to the working population, and 70.1% of them were male. Most commonly, the etiology of nerve lesion was trauma (63.3%) or iatrogenic injury (28.6%), while the less common origin was idiopathic (4.1%) or neoplastic (4.1%). The most frequent location of the lesion was in the upper arm, followed by the elbow and forearm. Fracture-related contusion was the most common mechanism (29.9%), followed by postoperative fibrosis (17.7%), lacerations (17.7%), and compression (15.6%).

Conclusion

Based on the fact that traumatic or iatrogenic injuries constitute the majority of cases, with their relevant mechanisms and upper arm predomination, it is crucial to raise awareness and understanding of the radial nerve injuries among orthopedic surgeons to decrease the numbers of these patients and properly preserve or treat them within the initial surgery.

Treatment of upper extremity nerve defects by direct suturing in high elbow or wrist flexion

PURPOSE

To evaluate functional outcomes after direct suturing of upper extremity nerve defects in high elbow or wrist flexion.

METHODS

A retrospective review was conducted in patients treated for median, ulnar, or radial nerve defects between 2011 and 2019. Inclusion criteria were a defect > 1 cm and a minimal follow-up period of 1 year. Nerve defects were bridged by an end-to-end suture in 90° elbow flexion or 70° wrist flexion for 6 weeks.

RESULTS

Nine patients with a mean age of 30.2 years were included. The patients presented with two ulnar nerve defects, four median nerve defects, and three radial nerve defects at various levels. The mean time to surgery was 13.5 weeks for recent injuries. The mean defect length was 2.9 cm, and the mean follow-up time was 22.4 months. Two patients had joint stiffness that was more likely related to the associated injuries than the 6-week immobilization. Successful outcomes were achieved in eight of the nine patients. Meaningful motor recovery was observed in seven patients, and all recovered meaningful sensation. Excellent nerve recovery was noted in pediatric patients and in those with distal nerve defects.

CONCLUSION

Temporary high joint flexion allows for direct coaptation of upper extremity nerve defects up to 4 cm located near the elbow or wrist. In this small and heterogenous cohort, functional outcomes seemed to be comparable to those obtained with short autografting.

How miRNAs Regulate Schwann Cells during Peripheral Nerve Regeneration-A Systemic Review

A growing body of studies indicate that small noncoding RNAs, especially microRNAs (miRNA), play a crucial role in response to peripheral nerve injuries. During Wallerian degeneration and regeneration processes, they orchestrate several pathways, in particular the MAPK, AKT, and EGR2 (KROX20) pathways. Certain miRNAs show specific expression profiles upon a nerve lesion correlating with the subsequent nerve regeneration stages such as dedifferentiation and with migration of Schwann cells, uptake of debris, neurite outgrowth and finally remyelination of regenerated axons. This review highlights (a) the specific expression profiles of miRNAs upon a nerve lesion and (b) how miRNAs regulate nerve regeneration by acting on distinct pathways and linked proteins. Shedding light on the role of miRNAs associated with peripheral nerve regeneration will help researchers to better understand the molecular mechanisms and deliver targets for precision medicine.

Functional Recovery following Repair of Long Nerve Gaps in Senior Patient 2.6 Years Posttrauma

Sensory nerve grafts are the clinical “gold standard” for repairing peripheral nerve gaps. However, reliable good-to-excellent recovery develops only for gaps less than 3–5 cm, repairs performed less than 3–5 months posttrauma, and patients aged less than 20–25 years. As the value of any variable increases, the extent of recovery decreases precipitously, and if the values of any two or all increase, there is little to no recovery. One 9-cm-long and two 11-cm-long nerve gaps in a 56-year-old patient were repaired 2.6 years posttrauma. They were bridged with two sensory nerve grafts within an autologous platelet-rich plasma-filled collagen tube. Both were connected to the proximal ulnar nerve stump, with one graft end to the distal motor and the other to the sensory nerve branches. Although presurgery the patient suffered chronic level 10 excruciating neuropathic pain, it was reduced to 6 within 2 months, and did not increase for more than 2 years. Motor axons regenerated across the 9-cm gap and innervated the appropriate two measured muscles, with limited muscle fiber recruitment. Sensory axons regenerated across both 11-cm gaps and restored normal topographically correct sensitivity to stimuli of all sensory modalities, including static two-point discrimination of 5 mm, and pressure of 2.83 g to all regions innervated by both sensory nerves. This novel technique induced a significant long-term reduction in chronic excruciating neuropathic pain while promoting muscle reinnervation and complete sensory recovery, despite the values of all three variables that reduce or prevent axon regeneration and recovery being simultaneously large.

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

ABSTRACT

Events causing acute stress to the health care system, such as the COVID-19 pandemic, place clinical decisions under increased scrutiny. The priority and timing of surgical procedures are critically evaluated under these conditions, yet the optimal timing of procedures is a key consideration in any clinical setting. There is currently no single article consolidating a large body of current evidence on timing of nerve surgery. MEDLINE and EMBASE databases were systematically reviewed for clinical data on nerve repair and reconstruction to define the current understanding of timing and other factors affecting outcomes. Special attention was given to sensory, mixed/motor, nerve compression syndromes, and nerve pain. The data presented in this review may assist surgeons in making sound, evidence-based clinical decisions regarding timing of nerve surgery.

Distal pronator teres motor branch transfer for wrist extension restoration in radial nerve paralysis

OBJECTIVE

The authors describe the anatomy of the motor branches of the pronator teres (PT) as it relates to transferring the nerve of the extensor carpi radialis brevis (ECRB) to restore wrist extension in patients with radial nerve paralysis. They describe their anatomical cadaveric findings and report the results of their nerve transfer technique in several patients followed for at least 24 months postoperatively.

METHODS

The authors dissected both upper limbs of 16 fresh cadavers. In 6 patients undergoing nerve surgery on the elbow, they dissected the branches of the median nerve and confirmed their identity by electrical stimulation. Of these 6 patients, 5 had had a radial nerve injury lasting 7-12 months, underwent transfer of the distal PT motor branch to the ECRB, and were followed for at least 24 months.

RESULTS

The PT was innervated by two branches: a proximal branch, arising at a distance between 0 and 40 mm distal to the medial epicondyle, responsible for PT superficial head innervation, and a distal motor branch, emerging from the anterior side of the median nerve at a distance between 25 and 60 mm distal to the medial epicondyle. The distal motor branch of the PT traveled approximately 30 mm along the anterior side of the median nerve; just before the median nerve passed between the PT heads, it bifurcated to innervate the deep head and distal part of the superficial head of the PT. In 30% of the cadaver limbs, the proximal and distal PT branches converged into a single trunk distal to the medial epicondyle, while they converged into a single branch proximal to it in 70% of the limbs. The proximal and distal motor branches of the PT and the nerve to the ECRB had an average of 646, 599, and 457 myelinated fibers, respectively.All patients recovered full range of wrist flexion-extension, grade M4 strength on the British Medical Research Council scale. Grasp strength recovery achieved almost 50% of the strength of the contralateral side. All patients could maintain their wrist in extension while performing grasp measurements.

CONCLUSIONS

The distal PT motor branch is suitable for reinnervation of the ECRB in radial nerve paralysis, for as long as 7-12 months postinjury.

Long Segment, Mixed Sensorimotor Nerve Reconstruction with Allograft: A Case Report of High Radial Nerve Injury

CASE

A 35-year-old man sustained a Grade I open right mid-diaphyseal humerus fracture and high radial nerve transection from a motor vehicle accident. Acute humeral plate osteosynthesis and radial nerve reconstruction using an intercalary 4-cm processed nerve allograft (PNA) was performed. Five years postoperatively, elbow extension, forearm supination, and wrist extension were 5/5 strength and independent digital extension was 5-/5. Radial nerve sensation recovered to 90% of the uninjured side.

CONCLUSIONS

Use of PNA resulted in outcomes comparable with or superior to autograft reconstruction or secondary tendon transfers and is a reasonable reconstructive option for similar acute, mixed sensorimotor nerve injuries.

Debates to personal conclusion in peripheral nerve injury and reconstruction: A 30-year experience at Chang Gung Memorial Hospital

Significant progress has been achieved in the science and management of peripheral nerve injuries over the past 40 years. Yet there are many questions and few answers. The author, with 30 years of experience in treating them at the Chang Gung Memorial Hospital, addresses debates on various issues with personal conclusions. These include: (1) Degree of peripheral nerve injury, (2) Timing of nerve repair, (3)Technique of nerve repair, (4) Level of brachial plexus injury,(5) Level of radial nerve injury,(6) Traction avulsion amputation of major limb, (7) Proximal Vs distal nerve transfers in brachial plexus injuries and (8) Post paralysis facial synkinesis.

Updates on and Controversies Related to Management of Radial Nerve Injuries

Radial nerve injuries are among the most common major traumatic peripheral nerve injuries. Recent literature has updated our knowledge of aspects ranging from radial nerve anatomy to treatment options. Observation and tendon transfers were, and still are, the mainstays of management. However, the improved outcomes of nerve repair even 5 months after injury have changed the treatment algorithm. Nerve repair techniques using conduits, wraps, autograft, and allograft allow tension-free coaptations to improve success. Nerve transfers have evolved to allow a more anatomic recovery of function if used in a timely manner. This review offers an update on radial nerve injuries that reflects recent advances.

Outcomes of Radial Nerve Grafting In Children After Distal Humerus Fracture

PURPOSE

To report the results of radial nerve grafting in 7 children who sustained a radial nerve injury following a distal humeral fracture.

METHODS

Seven children, mean age 6 years (range, 4-11 years), underwent nerve grafting for radial nerve injuries following distal humeral fractures. The mean interval between injury and surgery was 6.7 months (range, 6-9 months). In all cases, 3 sural nerve graft cables were used, of mean length 8.6 cm (range, 6-12 cm). Mean follow-up was 19.9 months (range, 12-24 months). Wrist, finger, and thumb extension range of motion and strength were evaluated at final follow-up, using the British Medical Research Council (BMRC) rating scale.

RESULTS

The radial nerve was entrapped within the fracture site in 2 patients, and in 5, it was completely interrupted without entrapment. All patients obtained full active wrist extension with grade M4 BMRC strength. For finger extension, all patients were graded as M4, obtaining full metacarpophalangeal finger and thumb extension, with the wrist in neutral in 3 patients and fully extended in 4. During the thumbs-up test, 4 patients achieved complete extension of all thumb joints, and 3 exhibited metacarpophalangeal extension lag, averaging 30°.

CONCLUSIONS

Nerve grafting of radial nerve injuries at the level of the distal humerus in children can yield excellent outcomes.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic V.

Results of nerve grafting in radial nerve injuries occurring proximal to the humerus, including those within the posterior cord

OBJECTIVE Results of radial nerve grafting are largely unknown for lesions of the radial nerve that occur proximal to the humerus, including those within the posterior cord. METHODS The authors describe 13 patients with proximal radial nerve injuries who were surgically treated and then followed for at least 24 months. The patients' average age was 26 years and the average time between accident and surgery was 6 months. Sural nerve graft length averaged 12 cm. Recovery was scored according to the British Medical Research Council (BMRC) scale, which ranges from M0 to M5 (normal muscle strength). RESULTS After grafting, all 7 patients with an elbow extension palsy recovered elbow extension, scoring M4. Six of the 13 recovered M4 wrist extension, 6 had M3, and 1 had M2. Thumb and finger extension was scored M4 in 3 patients, M3 in 2, M2 in 2, and M0 in 6. CONCLUSIONS The authors consider levels of strength of M4 for elbow and wrist extension and M3 for thumb and finger extension to be good results. Based on these criteria, overall good results were obtained in only 5 of the 13 patients. In proximal radial nerve lesions, the authors now advocate combining nerve grafts with nerve or tendon transfers to reconstruct wrist, thumb, and finger extension.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Nerve Repair and Nerve Grafting

Direct repair and nerve autografting are primary options in the treatment of upper extremity peripheral nerve injuries. Deciding between these surgical options depends on the mechanism of injury, time since injury, and length of repair defect. Principles of direct repair and nerve autografting are reviewed. Finally, a literature-based review of the outcomes of upper extremity peripheral nerve repair and autografting is provided. Taken together, this article provides relevant and recent data for surgeons regarding patient selection, technique selection, surgical technique, surgical outcomes, and prognostic factors that will aid surgeons treating patients with upper extremity peripheral nerve injuries.

Results of nerve grafting in radial nerve injuries occurring proximal to the humerus, including those within the posterior cord

OBJECT

Results of radial nerve grafting are largely unknown for lesions of the radial nerve that occur proximal to the humerus, including those within the posterior cord.

METHODS

The authors describe 13 patients with proximal radial nerve injuries who were surgically treated and then followed for at least 24 months. The patients’ average age was 26 years and the average time between accident and surgery was 6 months. Sural nerve graft length averaged 12 cm. Recovery was scored according to the British Medical Research Council (BMRC) scale, which ranges from M0 to M5 (normal muscle strength).

RESULTS

After grafting, all 7 patients with an elbow extension palsy recovered elbow extension, scoring M4. Six of the 13 recovered M4 wrist extension, 6 had M3, and 1 had M2. Thumb and finger extension was scored M4 in 3 patients, M3 in 2, M2 in 2, and M0 in 6.

CONCLUSIONS

The authors consider levels of strength of M4 for elbow and wrist extension and M3 for thumb and finger extension to be good results. Based on these criteria, overall good results were obtained in only 5 of the 13 patients. In proximal radial nerve lesions, the authors now advocate combining nerve grafts with nerve or tendon transfers to reconstruct wrist, thumb, and finger extension.

Nerve ultrasound identifies abnormalities in the posterior interosseous nerve in patients with proximal radial neuropathies

INTRODUCTION

The radial nerve and posterior interosseous nerve (PIN) are prone to injury at multiple sites. Electrodiagnostic (EDx) studies may only identify the most proximal lesion. Nerve ultrasound could augment EDx by visualizing additional pathology.

METHODS

This investigation was a retrospective examination of ultrasound and EDx from 26 patients evaluated for posterior cord/radial/PIN lesions.

RESULTS

Eighteen of 26 patients had abnormalities on EDx (15 radial, 2 PIN, 1 posterior cord). Ultrasound identified 15 of 18 (83%) of the EDx abnormalities and provided additional diagnostic information. In 6 of 15 (40%) patients with EDx evidence of radial neuropathy, ultrasound identified both radial nerve enlargement and additional, unsuspected PIN enlargement (53% to 339% enlarged vs. unaffected side). Ultrasound also identified: nerve (dis)continuity at the trauma site (n = 8); and nerve tumor (n = 2; 1 with normal EDx).

CONCLUSION

In radial neuropathy, ultrasound often augments EDx studies and identifies a second lesion in the PIN. Further studies are required to determine the etiology and significance of this additional distal pathology.

Radial nerve lacerations--the outcome of end-to-end repairs in penetrating trauma

Due to its mostly motor content, repair of the radial nerve is considered to yield favourable results. This is despite the fact that there are limited studies looking at the outcomes of end-to-end repair secondary to sharp penetrating trauma. We retrospectively reviewed the outcome of a series of repaired level 2 and level 3 radial nerves following penetrating stab injuries. Twenty-seven cases with adequate follow-up were included. All the patients underwent direct end-to-end repair. We evaluated the motor recovery of the target muscles using the British Medical Research Council (MRC) grading system. Wrist extension recovered in 93% of cases at a mean of six months. Finger extension recovered in 74% and thumb extension in 52% of cases within the follow-up period. We conclude that end-to-end repair is possible in the majority of level 2 and level 3 radial nerve lacerations secondary to penetrating stab injuries. Acceptable results can be expected.

Factors predicting sensory and motor recovery after the repair of upper limb peripheral nerve injuries

OBJECTIVE:

To investigate the factors associated with sensory and motor recovery after the repair of upper limb peripheral nerve injuries.

DATA SOURCES:

The online PubMed database was searched for English articles describing outcomes after the repair of median, ulnar, radial, and digital nerve injuries in humans with a publication date between 1 January 1990 and 16 February 2011.

STUDY SELECTION:

The following types of article were selected: (1) clinical trials describing the repair of median, ulnar, radial, and digital nerve injuries published in English; and (2) studies that reported sufficient patient information, including age, mechanism of injury, nerve injured, injury location, defect length, repair time, repair method, and repair materials. SPSS 13.0 software was used to perform univariate and multivariate logistic regression analyses and to investigate the patient and intervention factors associated with outcomes.

MAIN OUTCOME MEASURES:

Sensory function was assessed using the Mackinnon-Dellon scale and motor function was assessed using the manual muscle test. Satisfactory motor recovery was defined as grade M4 or M5, and satisfactory sensory recovery was defined as grade S3⁺ or S4.

RESULTS:

Seventy-one articles were included in this study. Univariate and multivariate logistic regression analyses showed that repair time, repair materials, and nerve injured were independent predictors of outcome after the repair of nerve injuries (P < 0.05), and that the nerve injured was the main factor affecting the rate of good to excellent recovery.

CONCLUSION:

Predictors of outcome after the repair of peripheral nerve injuries include age, gender, repair time, repair materials, nerve injured, defect length, and duration of follow-up.

Unusual radial nerve injury by a locking compression plate for humerus fracture

The management of primary and secondary radial nerve palsy associated with humeral shaft fractures is still controversial. Radial nerve function is likely to return spontaneously after primary as well as secondary radial nerve palsy in the absence of any level of neurotmesis. Identification and protection of the radial nerve during surgery may prevent secondary nerve palsy, but is not always performed and depends on the location of the fracture, and the experience and preference of the surgeon. We report a case of a healthy 40-year-old woman, referred to our hospital with a complete radial nerve palsy and a failed plate fixation of a right humeral shaft fracture. During exploration of the radial nerve and surgical revision of the fracture, we found the nerve entrapped by the plate and partially transected by a screw. Full recovery of radial nerve function occurred after neurolysis and microscopic neurorrhaphy.

Difficulty in Clinical Evaluation of Radial Nerve Injury due to Multiple Trauma to the Humerus, Wrist, and Hand

Radial nerve damage is frequently encountered in humeral fractures. The radial nerve is primarily damaged when the humerus gets fractured, while secondary damage maybe due to post-traumatic manipulations and surgical exploration. High impact traumatic nerve injury, serious neuropathic pain, lack of response to therapeutic interventions, and indifference to the Tinel test are indications for surgical intervention. Since most humeral fracture-induced low impact radial nerve injuries resolve spontaneously, conservative therapy is preferred. We present a patient with humeral fracture-associated radial nerve injury, accompanied with digital amputation and flexor tendon avulsion on the same arm. These injuries required immediate surgery, thus rendering the clinical evaluation of the radial nerve impossible. We would like to highlight and discuss the inherent difficulties associated with multiple trauma of the upper arm.

Transfer of median and ulnar nerve fascicles for lesions of the posterior cord in infraclavicular brachial plexus injury: report of 2 cases

In infraclavicular lesions of brachial plexus, severe lesions of the posterior cord often occur when medial and lateral cord function is preserved to a greater or lesser extent. In these cases, shoulder function may be preserved by activity of the muscles innervated by the suprascapular nerve, but complete paralysis exists in the deltoid, triceps, and brachioradialis, and all wrist and finger extensors. Classical reconstruction procedures consist of nerve grafts, but their results in adults are disappointing. We report an approach transferring: (1) an ulnar nerve fascicle to the motor branch of the long portion of the triceps brachii muscle, (2) a median nerve branch from the pronator teres to the motor branch of the extensor carpi radialis longus, and (3) a median nerve branch from the flexor carpi radialis to the posterior interosseous nerve. We describe the procedure and report 2 clinical cases showing the effectiveness of this technique for restoring extension of the elbow, wrist, and fingers in the common infraclavicular lesions of the brachial plexus affecting the posterior cord.

Acute closed radial nerve injury

We present a 45-year-old patient who had acute radial nerve palsy following a blunt trauma without any fracture or dislocation. He was injured by strucking in a combat three months ago. The patient has been followed by application of a long-arm plaster cast before referred to our clinic. Preoperative electromyoneurography and magnetic resonance imaging (MRI) indicated that there was a radial nerve injury on humeral groove. The British Medical Research Council (MRC) grade was 2/5 on his wrist preoperatively. The patient underwent an operation under general anesthesia. It was seen to be a second-degree nerve injury. The patient has subsequently regained full movement on his wrist and finger extension in six months. We suggest that a detailed clinical and electrodiagnostical evaluation is necessary in patients who have radial nerve injury when deciding the treatment, conservative or surgical.