Outcomes of Radial Nerve Grafting In Children After Distal Humerus Fracture

Retrograde peripheral nerve regeneration from sensory to motor pathways in rats: a new experimental concept in nerve repair

BACKGROUND

The polarity of nerve grafts does not interfere with axon growth. Our goal was to investigate whether axons can regenerate in a retrograde fashion within sensory pathways and then extend into motor pathways, leading to muscle reinnervation.

METHODS

Fifty-four rats were randomized into four groups. In Group 1, the ulnar nerve was connected end-to-end to the superficial radial nerve after neurectomy of the radial nerve in the axilla. In Group 2, the ulnar nerve was connected end-to-end to the radial nerve distal to the humerus; the radial nerve then was divided in the axilla. In Group 3, the radial nerve was divided in the axilla, but no nerve reconstruction was performed. In Group 4, the radial nerve was crushed in the axilla. Over 6 months, we behaviorally assessed the recovery of toe spread in the right operated-upon forepaw by lifting the rat by its tail and lowering it onto a flat surface. Six months after surgery, rats underwent reoperation, nerve transfers were tested electrophysiologically, and the posterior interosseous nerve (PIN) was removed for histological evaluation.

RESULTS

Rats in the crush group recovered toe spread between 5 and 8 days after surgery. Rats with nerve transfers demonstrated electrophysiological and histological findings of nerve regeneration but no behavioral recovery.

CONCLUSIONS

Ulnar nerve axons regrew into the superficial radial nerve and then into the PIN to reinnervate the extensor digitorum communis. We were unable to demonstrate behavioral recovery because rats cannot readapt to cross-nerve transfer.

Radial Nerve Palsy Associated with Humeral Shaft Fractures in Children

Background

This is the first systematic review of the relationship between humeral shaft fractures and radial nerve palsy in children. The present comprehensive review is aimed at identifying important clinical findings between humeral diaphysis fractures and radial nerve injuries and assessing the effects of treatment.

Methods

We searched electronic bibliographic databases, including PubMed, the Cochrane Library, Scopus, and Web of Knowledge, until March 2022. This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the patients, interventions, comparisons, outcomes guidelines.

Results

We identified 23 original papers, of which 10 were eligible for further analysis. Cases of 32 young patients with radial nerve palsy were identified and analyzed. The prevalence of radial nerve palsy was 4.34% (eight cases out of 184 patients with humeral shaft fractures). The radial nerve was most often associated with a simple transverse fracture (12A3, 17 cases (65.4%)).

Conclusions

Radial nerve injury in humeral shaft fractures in children is rare, with a frequency of 4.34%. We highly recommend early surgical nerve exploration with transverse fractures in the distal third segment combined with primary radial palsy. Furthermore, we recommend making thoughtful decisions regarding early nerve exploration in the Holstein-Lewis fractures. In addition, consideration of early surgical nerve exploration in fractures resulting from high-energy trauma and open fractures despite their morphology is recommended.

Management of Traumatic Nerve Palsies in Paediatric Supracondylar Humerus Fractures: A Systematic Review

Purpose: Up to 12% of paediatric supracondylar humerus fractures (SCHFs) have an associated traumatic nerve injury. This review aims to summarize the evidence and guide clinicians regarding the timing of investigations and/or surgical interventions for traumatic nerve palsies after this injury. Methods: A formal systematic review was undertaken in accordance with the Joanna Briggs Institute (JBI) methodology for systematic reviews and PRISMA guidelines. Manuscripts were reviewed by independent reviewers against the inclusion and exclusion criteria, and data extraction, synthesis, and assessment for methodological quality were undertaken. Results: A total of 51 manuscripts were included in the final evaluation, reporting on a total of 510 traumatic nerve palsies in paediatric SCHFs. In this study, 376 nerve palsies recovered without any investigation or intervention over an average time of 19.5 weeks. Comparatively, 37 went back to theatre for exploration beyond the initial treatment due to persistent deficits, at an average time of 4 months. The most common finding at the time of exploration was entrapment of the nerve requiring neurolysis. A total of 27 cases did not achieve full recovery regardless of management. Of the 15 reports of nerve laceration secondary to paediatric SCHFs, 13 were the radial nerve. Conclusions: Most paediatric patients who sustain a SCHF with associated traumatic nerve injury will have full recovery. Delayed or no recovery of the nerve palsy should be considered for exploration within four months of the injury; earlier exploration should be considered for radial nerve palsies.

Radial nerve lesion after medial epicondyle osteosynthesis in a pediatric patient: A rare complication of surgery

Fractures of the medial epicondyle are relatively common in children and may be associated with nerve lesion, especially in case of displacement. Incarceration of the ulnar nerve in the fracture site is feared in Watson-Jones stage II, rarely directly related to osteosynthesis. Depending on the degree of fracture displacement, various osteosynthesis techniques may be used; nerve injuries are a rare but known complication of these procedures. We report a case of radial nerve injury related to pinning osteosynthesis of a medial epicondyle fracture.

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.

MCP extensors respond faster than flexors in individuals with severe-to-moderate stroke-caused impairment: Evidence of uncoupled neural pathways

Damage in the corticospinal system following stroke produces imbalance between flexors and extensors in the upper extremity, eventually leading to flexion-favored postures. The substitution of alternative tracts for the damaged corticospinal tract is known to excessively activate flexors of the fingers while the fingers are voluntarily being extended. Here, we questioned whether the cortical source or/and neural pathways of the flexors and extensors of the fingers are coupled and what factor of impairment influences finger movement. In this study, a total of seven male participants with severe-to-moderate impairment by a hemiplegic stroke conducted flexion and extension at the metacarpophalangeal (MCP) joints in response to auditory tones. We measured activation and de-activation delays of the flexor and extensor of the MCP joints on the paretic side, and force generation. All participants generated greater torque in the direction of flexion (p = 0.017). Regarding co-contraction, coupled activation of the extensor is also made during flexion in the similar way to coupled activation of the flexor made during extension. As opposite to our expectation, we observed that during extension, the extensor showed marginally significantly faster activation (p = 0.66) while it showed faster de-activation (p = 0.038), in comparison to activation and de-activation of the flexor during flexion. But movement smoothness was not affected by those factors. Our results imply that the cortical source and neural pathway for the extensors of the MCP joints are not coupled with those for the flexors of the MCP joints.

Treatment of Radial Nerve Palsy in Paediatric Humeral Shaft Fractures. STROBE-Compliant Investigation

Background and Objectives:Due to the rarity of radial nerve palsy in humeral shaft fractures in the paediatric population and the lack of data in the literature, the purpose of our study was to report the treatment results of six children who sustained a radial nerve injury following a humeral shaft fracture. Materials and Methods: We treated six paediatric patients with radial nerve palsy caused by a humeral shaft fracture in our department from January 2011 to June 2022. The study group consisted of four boys and one girl aged 8.6 to 17.2 (average 13.6). The mean follow-up was 18.4 months. To present our results, we have used the STROBE protocol designed for retrospective observational studies. Results:We diagnosed two open and four closed humeral shaft fractures. Two simple transverse AO 12A3c; one simple oblique AO 12A2c; two simple spiral AO 12A1b/AO 12A1c and one intact wedge AO 12B2c were recognized. The humeral shaft was affected in the distal third five times and in the middle third one time. In our study group, we found two cases of neurotmesis; two entrapped nerves within the fracture; one stretched nerve over the bone fragments and one case of neuropraxia. We found restitution of the motor function in all cases. For all patients, extensor muscle strength was assessed on the grade M4 according to the BMRC scale (except for a patient with neuropraxia-M5). The differences in patients concerned the incomplete extension at the radiocarpal and metacarpophalangeal (MCP) joints. Conclusions: In our small case series, humeral shaft fractures complicated with radial nerve palsy are always challenging medical issues. In paediatric patients, we highly recommend an US examination where it is possible to be carried out to improve the system of decision making. Expectant observation with no nerve exploration is reasonable only in close fractures caused by low-energy trauma. Early surgical nerve exploration related with fracture stabilisation is highly recommended in fractures after high-energy trauma, especially in open fractures and where symptoms of nerve palsy appear at any stage of conservative treatment.

Functional outcome after transfer of brachialis on anterior interosseous and supinator on posterior interosseous nerves: A preliminary report

OBJECTIVE

Traumatic spinal cord injury (SCI) resulting in tetraplegia is a leading cause of morbidity among young adults worldwide and its management remains challenging. Restoring hand function in these patients must be considered a top priority with great impact on their quality of life (QOL); although nerve and tendon transfer have been extensively described, type of procedure to be chosen is not standardized and few studies have determined the functional outcome of those procedure and their impact on QOL is still poorly assessed. We report a preliminary retrospective study regarding feasibility and functional outcomes of nerve transfer procedures including bilateral brachialis nerve on anterior interosseous nerve (AIN) and supinator branch on posterior interosseous nerve (PIN) for hand reanimation following SCI focusing on the impact of these procedures on QOL.

METHODS

We performed a retrospective study involving patient sustained SCI and underwent nerve transfer of brachialis branch from musculocutaneous nerve on AIN and supinator branch from the trunk of the radial nerve on the PIN. We included 11 patients (14 limbs) with traumatic SCI resulting in C4 level tetraplegia in five patients, C5 in four and C6 and C7 in one case each, with a median age of 31.5 years underwent surgery at a median of 10 months after injury; including both transfers in 10 cases and AIN reanimation only in one. Functional assessment including medical research council (MCR) grade, graded redefined assessment of strength sensation and prehension (GRASSP) and spinal cord independence measure (SCIM) were performed at least 12 months follow up.

RESULTS

Thirteen PIN innervated muscles achieved an MRC score ≥3/5 whereas AIN supplied muscles in 5 out of 15. GRASSP qualitative measure improved from a baseline value of 1 to 2, while quantitative measure passed from 1 to 3 after 12 months; the difference was statistically significant (p = .005 and p = .008, respectively). SCIM self-care sub-score also statistically significant improved from 3 to 4 at 12 months (p = .016). No complication or donor morbidity occurred.

CONCLUSIONS

Functional performance has been significantly improved by nerve transfer procedures 1 year after surgery. Nerve transfers may represent a valuable option for the restoration of the hand function in patients with tetraplegia with minor or no morbidity.

Successful Delayed Neurolysis of the Median Nerve in a Teenager 7 years After Supracondylar Fracture: A Case Report and Review of the Literature

ABSTRACT

Supracondylar humeral fractures are the commonest elbow fractures in childhood, associated with a high rate of neurological complications. We present the case of a 14-year-old adolescent girl with persisting daily pain, lack of sensation, and strength to her left hand after a displaced supracondylar fracture 7 years earlier. At the time of the fracture, she underwent closed reduction and percutaneous Kirschner wire fixation. During revision surgery, half of the median nerve was found embedded in bone at the level consistent with the healed fracture site. Neurolysis of the fascicles adherent to the bone was performed. Postoperatively, the patient had complete recovery of sensation, reduced pain, and a 2.5-fold improvement of grip strength. This case shows that there is a role for delayed neurolysis in children.

Current concepts in diagnosis and management of common upper limb nerve injuries in children

Peripheral nerve injuries (PNI) of the upper limb are a common event in the paediatric population, following both fractures and soft tissues injuries. Open injuries should in theory be easier to identify and the repair of injured structures performed as soon as possible in order to obtain a satisfying outcome. Conversely, due to the reduced compliance of younger children during clinical assessment, the diagnosis of a closed nerve injury may sometimes be delayed. As the compliance of patients is influenced by pain, anxiety and stress, the execution of the clinical manoeuvres intended to identify a loss of motor function or sensibility, can be impaired. Although the majority of PNI are neuroapraxias resulting in spontaneous recovery, there are open questions regarding certain aspects of closed PNI, e.g. when to ask for electrophysiological exams, when and how long to wait for a spontaneous recovery and when a surgical approach becomes mandatory. The aim of the article is therefore to analyse the main aspects of the different closed PNI of the upper limb in order to provide recommendations for timely and correct management, and to determine differences in the PNI treatment between children and adults.

Transfer of the Distal Anterior Interosseous Nerve for Thumb Motion Reconstruction in Radial Nerve Paralysis

PURPOSE

With nerve or tendon surgery, the results of thumb reconstruction to treat radial nerve paralysis are suboptimal. The goals of this study were to describe the anatomy of the deep branch of the posterior interosseous nerve (PIN) to the thumb extensor muscles (DBPIN), and to report the clinical results of transferring the distal anterior interosseous nerve (DAIN) to the DBPIN.

METHODS

The PIN was dissected in 12 fresh upper limbs. Myelinated nerve fibers in the DBPIN and DAIN were counted. Five patients with radial nerve paralysis underwent transfer of the motor branch to the flexor carpi radialis to the PIN and a motor branch of the pronator teres to the extensor carpi radialis brevis. In addition, these patients had selective reconstruction of thumb motion by transferring the DAIN to the DBPIN, through either a combined volar and dorsal approach (n = 2) or a single dorsal approach (n = 3) with division of the interosseous membrane.

RESULTS

At the origin of the abductor pollicis longus, the DBPIN divided into a lateral branch that innervated the abductor pollicis longus and extensor pollicis brevis, and a medial branch that innervated the extensor pollicis longus and extensor index proprius. The number of myelinated nerve fibers in the DAIN corresponded to 65% of that of the DBPIN. In each of the 5 patients, full thumb motion at the trapeziometacarpal joint was restored with no, or minimal, extension lag at the metacarpophalangeal (MCP) joint.

CONCLUSIONS

The anatomy of the DBPIN is predictable. Transferring the DAIN to the DBPIN is feasible through a single dorsal approach, allowing full recovery of thumb motion.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic V.

Nerve Versus Tendon Transfer for Radial Nerve Paralysis Reconstruction

PURPOSE

With radial nerve lesions, the results of nerve transfers and how they objectively compare with the outcomes of tendon transfers remain unstudied. We compared the results after nerve transfer in patients with less than 12 months since radial nerve injury with the results after tendon transfer in patients not eligible for nerve surgery because of longstanding paralysis (minimum of 15 months).

METHODS

In 14 patients with radial nerve lesions incurred less than 12 months previously, we transferred the anterior interosseous nerve to the nerve of the extensor carpi radialis brevis (ECRB), while the nerve to the flexor carpi radialis was transferred to the posterior interosseous nerve. In 13 patients with lesions of longer duration, we transferred the pronator teres tendon to the ECRB, the flexor carpi ulnaris tendon to the extensor digitorum communis, and the palmaris longus to the rerouted extensor pollicis longus (EPL) tendon. At a final evaluation, we measured passive and active range of motion (ROM) of the wrist, finger, and thumb and grasp strength.

RESULTS

In a comparison of wrist flexion-extension ROM and grasp strength, we observed better recovery in the nerve transfer than in the tendon transfer group. In the tendon transfer group, we observed limitations in wrist flexion in 9 of the 13 patients and permanent radial deviation in 5. Half of the patients in the tendon transfer group needed to flex their wrist to fully extend their fingers, whereas finger extension was possible with the wrist either extended or at neutral in all patients following nerve transfer. After nerve transfer, extension at the first carpometacarpal joint was restored in 11 of the 14 patients, whereas this occurred in just 4 of the 13 patients following tendon transfer. In both groups, we observed a 30° lag in thumb metacarpophalangeal extension, which reflects poor recovery of EPL function.

CONCLUSIONS

Overall, we observed better outcomes in those who underwent nerve transfer versus tendon transfer procedures. However, room still remains for improved thumb motion with both procedures.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Peripheral nerve injuries in the pediatric population: a review of the literature. Part I: traumatic nerve injuries

OBJECTIVE

This article reviews the clinical results that can be obtained after repair of a traumatic peripheral nerve injury in the pediatric population.

METHODS

A systematic review of the published literature has been made.

RESULTS

Functional outcome after major nerve injuries is sometimes disappointing in adults. However, children have been reported to experience much better functional results after nerve repair than adults. Moreover, recovery generally is faster in children. The superior capacity of children's central nervous system to adapt to external or internal environmental changes (neural plasticity) and the shorter recovery distance from the axon repair site to the target muscle are claimed to be crucial determinants of their favorable outcomes. Moreover, even in the pediatric population, it has been demonstrated that functional results are better the younger the patient is, including better clinical results in those injured in early childhood (< 6 years old) than in those injured in adolescence. Other favorable prognostic factors include the type of nerve injury (with complete transections doing less well than crush injuries) and the timing of surgery (with better outcomes after early repairs).

CONCLUSIONS

All efforts should be done to repair in a timely and adequate fashion traumatic peripheral nerve injuries in children, as the results are good.