Morbidity of Nerve Transfers for Brachial Plexus Birth Injury: A Systematic Review

Current Concepts in Brachial Plexus Birth Injuries: A Comprehensive Narrative Review

Background

Brachial plexus birth injury (BPBI) encompasses a spectrum of upper extremity paralysis cases following childbirth. The etiology of BPBI is multifactorial, involving maternal, obstetric, and neonatal associative factors. Despite opportunities for spontaneous recovery, recent literature demonstrates that a significant proportion of infants experience residual deficits and functional limitations as they age. Understanding the complex anatomy of the brachial plexus, clinical presentations of the pathology, diagnostic workup, current treatment options, and common secondary sequelae is instrumental for appropriate management of BPBI.

Methods

Following a comprehensive search strategy used by the authors to identify relevant literature relating to the progression, patho-anatomy, clinical presentation, management, and treatment of BPBI, this comprehensive narrative review outlines current approaches to assess, manage, and advance BPBI care.

Results

We advocate for prompt referral to specialized multicenter brachial plexus clinics for accurate diagnosis, timely intervention, and individualized patient-centered assessment. Further research is needed to elucidate mechanisms of injury, refine diagnostic protocols, and optimize long-term outcomes.

Conclusions

Collaboration between healthcare providers and families is paramount in providing comprehensive care for infants with BPBI. This review offers insights into the current understanding and management of BPBI, highlighting the importance of tailored approaches and intraoperative decision-making algorithms to optimize functional outcomes.

Brachial plexus birth injury: advances and controversies

While there is considerable spontaneous recovery in most cases of brachial plexus birth injury, many children are left with significant problems that may lead to lifelong functional limitations, loss of work and social isolation. Detailed treatment with the right strategy can provide very valuable improvement in function. Over the past few years, the clinical approach to brachial plexus birth palsy has entered a new era in both diagnostic and surgical treatment methods. This article reviews four areas of management, the role of imaging in defining the severity of the injury, the optimal timing of for nerve exploration and reconstruction in appropriate cases, the advantages and potential complications of nerve transfers, and the role of physiotherapy. Available evidence is considered. Although it is difficult to make clear and precise inferences on a subject where there are many variables and considerable uncertainties, some currently accepted views will be summarized.Level of evidence: V.

Recent Advances in the Treatment of Brachial Plexus Birth Injury

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Describe methods of clinical evaluation for neurologic recovery in brachial plexus birth injury. 2. Understand the role of different diagnostic imaging modalities to evaluate the upper limb. 3. List nonsurgical strategies and surgical procedures to manage shoulder abnormality. 4. Explain the advantages and disadvantages of microsurgical nerve reconstruction and distal nerve transfers in brachial plexus birth injury. 5. Recognize the prevalence of pain in this population and the need for greater sensory outcomes evaluation.

SUMMARY

Brachial plexus birth injury (BPBI) results from closed traction injury to the brachial plexus in the neck during an infant's vertex passage through the birth canal. Although spontaneous upper limb recovery occurs in most instances of BPBI, some infants do not demonstrate adequate motor recovery within an acceptable timeline and require surgical intervention to restore upper limb function. This article reviews major advances in the management of BPBI in the past decade that include improved understanding of shoulder pathology and its impact on observed motor recovery, novel surgical techniques, new insights in sensory function and pain, and global efforts to develop standardized outcomes assessment scales.

Quantifying Donor Deficits Following Nerve Transfer Surgery in Tetraplegia

PURPOSE

Nerve transfer (NT) surgery can improve function in people with cervical spinal cord injury (SCI). However, the impact of donor nerve deficits remains unclear. The purpose of this study was to quantify donor deficits experienced by individuals with cervical SCI following NT.

METHODS

This prospective single-arm, comparative study included people with SCI undergoing upper extremity NTs. Myometry was used to assess muscle strength at baseline and follow-up. The Spinal Cord Independence Measure was used to measure the ability to perform activities of daily living.

RESULTS

Ten individuals underwent 20 NTs to restore elbow extension (donor, posterior deltoid; n = 2), hand opening (donor, supinator; n = 7), and hand closing (donor, brachialis; n = 11). Shoulder abduction strength decreased (-5.6% at early and -4.5% late follow-up) in the elbow extension NT. Wrist extension strength decreased at early (-46.9% ± 30.3) and increased by late (76.4% ± 154.0) follow-up in the hand opening NT. No statistically significant change in elbow flexion strength was noted in the hand closing NT. Spinal Cord Independence Measure scores did not change significantly between baseline and early postoperative follow-up; they improved at late follow-up.

CONCLUSIONS

Use of expendable donor nerves with redundant function to perform NT surgery has relatively little impact on strength or capacity to perform activities of daily living, even in the unique and highly vulnerable SCI population. Early, temporary loss in wrist extension strength can be seen after the supinator to posterior interosseous nerve transfer. This study offers quantitative data about possible diminution of donor function after NT, enabling hand surgeons to better counsel individuals contemplating upper extremity reconstruction.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic I.

Brachial Plexus Birth Injuries

Brachial plexus birth injuries (BPBIs) are typically traction type injuries to the newborn that occur during the delivery process. Although the incidence of these injuries has overall decreased from 1.5 to around 0.9 per 1000 live births in the United States over the past 2 decades, these injuries remain common, with incidence holding fairly steady from 2008 to 2014. Shoulder dystocia is the strongest identified risk factor, imparting a 100-fold greater risk. The newborn's shoulder is caught behind the mother's pubic bone, and traction performed on the child during delivery results in injury to the brachial plexus. Other risk factors associated with BPBI include macrosomia (birthweight > 4.5 kg), heavy for gestational age infants, birth hypoxia, gestational diabetes, and forceps or vacuum-assisted delivery. Breech presentation has also been described as a risk factor in the past, but there have been more recent data that challenge this association.

Brachial Plexus Birth Injuries: A Critical Analysis Review

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The incidence of brachial plexus birth injury (BPBI) in the United States is declining and now occurs in <1 per 1,000 births.

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The gold standard for predicting the need for early intervention remains serial examination.

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Early treatment of BPBI with reconstructive surgery requires the ability to perform both interposition nerve grafting and nerve transfers.

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Given the heterogeneity of lesions, the evidence is largely limited to retrospective comparative studies and case series.