The Effectiveness of Different Nerve Transfers in the Restoration of Elbow Flexion in Adults Following Brachial Plexus Injury: A Systematic Review and Meta-Analysis

Clinical assessment in brachial plexus injury surgery: systematic review and proposal for integrated evaluation among different medical departments

BACKGROUND

Brachial plexus injury (BPI) surgery involves diversity in surgical departments including plastic surgery, hand surgery, orthopedic surgery, and neurosurgery. There is a clear scarcity in terms of unified guidelines for outcome publications due to the absence of collaboration or consensus development between departments. This study aims to identify relevant clinical parameters and their standardized presentation to address this gap.

METHODS

A systematic review was carried out to identify the clinical outcomes and methodological characteristics of the studies published regarding BPI surgery according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA). Advanced search in PubMed was performed using the MeSH terms "Brachial Plexus Injury" (Major topic) AND "Surgery" (Subheading), obtaining a total of 2382 articles. Statistical analysis was performed, and the study was registered with the PROSPERO ID: CDR42022353785.

RESULTS

A total of 136 articles were included to the systematic review, and 11,949 patients were evaluated in different clinical outcomes according to the preferences of the authors. Traumatic events around the world are the most common cause of injury. The clinical components most reported were: British Medical Research Council in motor at 82.3%, visual analog scale in pain was 21.3%, sensitive components at 26.4%, and quality of life in 16.1% of the cases.

CONCLUSIONS

The lack of standardized clinical trials highlights the need to increase the level of evidence with the aim to identify clinical evaluations among all the diverse departments to provide optimal care for BPI treatment.

Outcomes for the shoulder and elbow following surgical reconstruction for traumatic brachial plexus injury in patients over 60 years

This study aims to investigate surgical outcomes in elderly patients aged over 60 years old, with brachial plexus injury, undergoing nerve reconstruction using nerve grafts and/or nerve transfers for shoulder and elbow function. Twenty-two patients met the inclusion criteria. Postoperative median shoulder abduction was 35° in the single nerve transfer group (n = 12) and less than 20° in the single nerve grafting group (n = 2). Patients over 65 tended to have poorer outcomes. For elbow flexion strength, a higher proportion of patients in the nerve transfer group (11/12 cases) achieved M3 or greater elbow flexion compared with the nerve grafting group (3/7 cases). Elbow extension also improved in the reconstructive group (9/13 cases). Given these findings, elbow flexion reconstruction is the first priority, while shoulder abduction, showing poor results, should not consume excessive neurotizers. Elbow extension is the second priority, achievable through nerve reconstruction.Level of evidence: IV.

Comparing the long-term results of Oberlin II versus intercostal neurotization for elbowflexion restoration (Prospective study)

BACKGROUND

Restoring elbow flexion following brachial plexus injury (BPI) is essential for improving arm function and quality of life in adults. This study aimed to compare the efficacy of Oberlin II and intercostal nerve (ICN) neurotization techniques for restoring elbow flexion in adults with upper and middle trunk brachial plexus palsy.

METHODS

This prospective study included 36 patients aged 18 to 50 years with traumatic upper and middle trunk brachial plexus palsy. The patients were divided into two groups: Group A consisted of 19 patients who underwent the Oberlin II procedure, while Group B included 17 patients treated with ICN neurotization. All patients were followed for at least 60 months.

RESULTS

Muscle reactivation occurred significantly earlier in the Oberlin II group compared to the ICN neurotization group (P = 0.012). Muscle strength grading also showed significant differences, with a higher proportion of patients achieving grade 4 and 4+ strength in the Oberlin II group compared to the ICN neurotization group (P = 0.041).

CONCLUSIONS

The Oberlin II neurotization technique demonstrated superior efficacy in restoring elbow flexion following BPI compared to ICN neurotization. It resulted in earlier muscle reactivation and higher levels of muscle strength, with a greater proportion of patients achieving grades 4 and 4+ strength.

The Epidemiology of Traumatic Brachial Plexus Injuries in England and Wales-A 32-Year Review

Background

Traumatic brachial plexus injuries (TBPI) are often devastating and life-changing and are thought to be becoming more prevalent. Several studies have investigated the epidemiology of TBPI in other countries (e.g., United States, Brazil); however, a similar analysis is yet to be undertaken in England and Wales. The aim of this cohort study was to determine the incidence and epidemiology of TBPI in England and Wales.

Methods

The Trauma Audit and Research Network database was reviewed to identify 1,297 eligible patients admitted with TBPI between 1990 and 2022. Patient demographics, injury mechanism, associated injuries, and outcomes were analyzed.

Results

The median age of patients with TBPI was 41 years, and 77% (n = 997) were male. There was a significant difference in age between male patients and female patients, with male patients aged younger than 18 years (confidence interval 14.4-21.3) at the time of injury. The predominant injury mechanism was vehicle collision (65%), with 62% riding motorcycle or quad bikes. The majority of other injuries resulted from falls less than 2 m (19%). Falls less than 2 m were particularly prevalent in patients aged older than 65 years, who represented 19% of the cohort. TBPI was commonly associated with other injuries (94%), predominately bony injuries including dislocations and fractures.

Conclusion

This is the first epidemiological study of TBPI within England and Wales. Vehicle incidents, particularly involving motorcycles, are the commonest cause of TBPI; however, there is a substantial cohort of elderly patients sustaining TBPI, often from falls. These findings may aid improved and earlier recognition of TBPI, enabling timely management.

Level of Evidence

Level III. See Instructions for Authors for a complete description of levels of evidence.

Cortical Neurotransmitters Measured by Magnetic Resonance Spectroscopy Change Following Traumatic Brachial Plexus Injury

Introduction  GABA (γ-aminobutyric acid) is the major inhibitory neurotransmitter in the brain. In response to injury within the central nervous system, GABA promotes cortical plasticity and represents a potential pharmacological target to improve functional recovery. However, it is unclear how GABA changes in the brain after traumatic brachial plexus injuries (tBPIs) which represents the rationale for this pilot study. Methods  We serially scanned seven males (mean age 42 years [SD 19] without head injury) up to 19 months after tBPIs. T1-weighted images (1-mm isotropic resolution) and J-edited spectra (MEscher-GArwood Point RESolved Spectroscopy [MEGA-PRESS], TE 68 ms, TR 2,000 ms, 2 cm isotropic voxels) were acquired using a MAGNETOM Prisma 3T (Siemens Healthcare, Erlangen, Germany). Data were analyzed in jMRUI blind to clinical information to quantify GABA, creatine plus phosphocreatine (Cr), and N-acetylaspartate (NAA) concentrations. Additionally, gray matter and white matter proportions were assessed using SPECTRIM software. Interhemispheric means were compared using linear methods. Confidence intervals (CIs) were generated to the 95% level. Results  Within weeks of injury, the hemisphere representing the injured upper limb had a significantly lower GABA:NAA ratio (mean difference 0.23 [CI 0.06-0.40]) and GABA:Cr ratio (mean difference 0.75 [CI 0.24-1.25]) than the uninjured side. There were no interhemispheric differences in NAA:Cr. By 12 months post-injury, interhemispheric differences in metabolite concentrations equalized. There was no difference in the proportion of gray matter, white matter, or cerebrospinal fluid between the injured and uninjured hemispheres. Conclusion  After brachial plexus injuries, there are interhemispheric differences in GABA concentrations within the sensory and motor cortex. This represents a potential pharmacological target that warrants further investigation.

Results of the Nerve Transfers and Secondary Procedures to Restore Shoulder and Elbow Function in Traumatic Upper Brachial Plexus Palsy

Background: Damage to the upper trunk of the brachial plexus, often caused by high-energy trauma, leads to significant functional impairment of the upper limb. This injury primarily affects the C5 and C6 roots, resulting in paralysis of muscles critical for shoulder and elbow function. If spontaneous nerve regeneration does not occur within 3-6 months post-injury, surgical intervention, including nerve transfers, is recommended to restore function. Methods: This study evaluates long-term outcomes of nerve transfer surgeries performed between 2013 and 2023 on 16 adult patients with post-traumatic brachial plexus injuries. The most common cause of injury was motorcycle accidents. Nerve transfers targeted shoulder and elbow function restoration, including transfer of the accessory nerve to the suprascapular nerve, the radial nerve branch to the long or medial head of the triceps brachii to the axillary nerve, or the transfer of motor fascicles of the ulnar and median nerves (double Oberlin) to the brachialis and biceps brachii motor nerves. Results: Postoperative results showed varying degrees of functional recovery. In the shoulder, most patients achieved stabilization and partial restoration of active movement, with average flexion up to 92° and abduction up to 78°. In the elbow, full flexion with M4 strength was achieved in 64% of patients. In both the shoulder and the elbow, double nerve transfers yield better long-term outcomes than single transfers. Secondary procedures, such as tendon transfers, were required in some cases to improve limb strength. Conclusions: The study concludes that nerve transfers offer reliable outcomes in restoring upper limb function, although additional surgeries may be necessary in certain cases.

Single versus double fascicular transfer for brachial plexus injuries: a systematic review and meta-analysis with meta-regression

The primary objective of this review was to assess whether double fascicular transfer has superior outcomes compared with single fascicular transfer for reanimation of elbow flexion. In total, 58 studies including 1388 patients (mean age 29 years [SD 8]) were included. Subgroup analysis comparing the severity of brachial plexus injury (C5-C6, C5-C7, C5-C8) showed no significant difference in the recovery of MRC grade 3 and 4. The aggregated mean Disabilities of Arm, Shoulder and Hand score was 38 for the single fascicular transfer group and 27 for the double fascicular transfer group. Meta-regression controlling for level of injury showed that double fascicular transfer and C5-C6 injury were significant predictors of achieving MRC grade 3, while double fascicular transfer and shorter duration of surgical delay were significant predictors of achieving MRC grade 4. When controlling for the level of injury, double fascicular transfer is associated with a greater likelihood of achieving MRC grade 3 and 4 compared to single fascicular transfer. Overall donor site morbidity was not significantly different between single fascicular transfer and double fascicular transfer.

Updates in diagnostic tools for diagnosing nerve injury and compressions

Predicting prognosis after nerve injury and compression can be challenging, even for the experienced clinician. Although thorough clinical assessment can aid diagnosis, we cannot always be precise about long-term functional recovery of either motor or sensory nerves. To evaluate the severity of nerve injury, surgical exploration remains the gold standard, particularly after iatrogenic injury and major nerve injury from trauma, such as brachial plexus injury. Recently, advances in imaging techniques (ultrasound, magnetic resonance imaging [MRI] and MR neurography) along with multimodality assessment, including electrodiagnostic testing, have allowed us to have a better preoperative understanding of nerve continuity and prediction of nerve health and possible recovery. This article outlines the current and potential roles for clinical assessment, exploratory surgery, electrodiagnostic testing ultrasound and MRI in entrapment neuropathies, inflammatory neuritis and trauma. Emphasis is placed on those modalities that are improving in diagnostic accuracy of nerve assessment before any surgical intervention.

Will preoperative combined MRI and high-resolution ultrasonography redefine brachial plexus imaging? A comparative study of preoperative MRI versus combined MRI and high-resolution ultrasonography in assessing usable C5, C6 root-stumps for intra-plexal nerve grafting

AIM

To compare the intraoperative findings with the preoperative imaging in detecting usable root stumps using magnetic resonance imaging (MRI) alone versus MRI combined with high-resolution ultrasonography (HRUS) in adults undergoing post-traumatic brachial plexus (BP) surgery. Further, when root stumps were present, the reliability of their measurements using both imaging methods was compared to their intraoperative length.

MATERIALS AND METHODS

A consecutive group of adults who were planned for post-traumatic BP surgery between July 2015 and April 2016 were evaluated prospectively. They underwent preoperative MRI and HRUS and the agreement (kappa value) between these imaging methods and their intraoperative findings in categorising roots were then compared. When stumps were present, the reliability of the extraforaminal measurements by each method were compared to their corresponding intraoperative stump length using intraclass correlation coefficients (ICC), and Bland-Altman plots.

RESULTS

Of the initial 60 patients, 48 patients with 82 roots were included in the study. Greater agreement was observed between HRUS and intraoperative findings in categorising BP root stumps (kappa value 0.70, SE 0.07) versus MRI and intraoperative findings (kappa value 0.42, SE 0.07). Similarly, there was a higher correlation between HRUS and intraoperative findings (ICC: 0.94, p<0.001) than that of MRI and intraoperative findings (ICC: 0.53, p<0.001) regarding stump length measurements.

CONCLUSION

Combining HRUS with MRI in the preoperative imaging of the adult BP injury can better predict the presence of usable nerve root stumps for intra-plexal nerve grafting. HRUS also gave reliable preoperative stump length measurements, and it was determined that a stump should be at least 1.3 cm to be deemed usable for nerve grafting.