Peripheral nerve decompression for pain relief in the setting of previous obstetrical brachial plexus injury: a retrospective case series.

PURPOSE: In children with previous obstetrical brachial plexus injury (OBPI), upper extremity pain is present in 45 to 66% of patients. Recent literature reports this as musculoskeletal or neuropathic in nature. The purpose of the study is to demonstrate that peripheral nerve decompression, and neurolysis may be an effective treatment for patients with upper extremity pain in the context of previous OBPI. METHODS: A retrospective chart review was performed on patients undergoing peripheral nerve decompression and neurolysis after OBPI by senior author. The primary outcome assessed was pain, and secondary outcome measure was range of motion of the wrist and elbow. Outcome measures were assessed preoperatively as well as at their subsequent follow-up. RESULTS: Six patients were included, with a mean age of 14 years old at time of decompression. Three patients underwent median nerve, two patients underwent ulnar nerve, and one patient underwent posterior interosseous nerve decompression. There was a substantial improvement in pain post-operatively, demonstrated by reduction or resolution of subjective pain in all patients and resolution of Tinel's sign. There was a modest improvement in range of motion. CONCLUSION: This study demonstrates an improvement in subjective pain and range of motion after decompression and neurolysis in small subset of OBPI patients. It generates the hypothesis that peripheral nerve compression is a source of pain that can be addressed in this population. Future research should focus on confirming this hypothesis and assessing treatment options on a larger scale.

"Popeye muscle" morphology in OBPI elbow flexion contracture.

BACKGROUND: The pathophysiology of elbow flexion contracture (EFC) in obstetrical brachial plexus injury (OBPI) is not established. In basic science models, neonatal denervation leads to impaired muscle growth. In clinical studies, diminished growth is correlated with extent of denervation, and improved with surgical repair. In EFC, the biceps are clinically short and round vs the contralateral size, termed the "Popeye muscle". The objective of this study was to determine if the biceps morphology (muscle belly and tendon length) in arms with EFC secondary to OBPI is different vs the contralateral. METHODS: This is a retrospective matched-cohort study. Patients with unilateral EFC (>20°) secondary to OBPI were identified (median = 6.6 years, range = 4.7-16.8). A blinded radiologist used computed tomography to measure length of the biceps short head muscle belly, and tendon bilaterally using standardised anatomical landmarks. RESULTS: Twelve patients were analyzed. The biceps muscle belly in the injured arm was shorter in all patients vs contralateral, mean difference = 3.6 cm (80%), p < 0.001. The biceps tendon in the injured arm was longer in all patients vs contralateral, mean difference = 1.13 cm (127%), p < 0.001. The total biceps length in the injured arm was shorter in all patients vs contralateral, mean difference = 2.5 cm (89%), p < 0.001. CONCLUSIONS: This is the first human study confirming growth discrepancy of an elbow flexor in EFC. Distinct biceps morphology is demonstrated, with a significantly shorter muscle belly and overall length, but longer tendon vs normal. This is termed the "Popeye muscle" for its irregular morphology. Findings are consistent with impaired limb growth in denervation.

'Wondering and waiting' after obstetrical brachial plexus injury: Are we underestimating the effects of the traumatic experience on the families?

BACKGROUND: Obstetrical brachial plexus injury (OBPI) in children can cause great distress to a family due to uncertain recovery, variability in spontaneous recovery and unclear indicators for surgery. OBJECTIVE: To investigate the impact of having a child with OBPI on the family and whether the Impact on Family Scale (IoFS) can assist in addressing family concerns. METHODS: A mixed-method (cross-sectional survey and semistructured interviews) study design was used. RESULTS: Thirty-eight families of children with OBPI completed the IoFS. Surgery significantly predicted a higher IoFS total impact score (P=0.02). No statistically significant association between the total impact score and severity or age was found, suggesting that impact on family was not dependent on these factors. Themes that emerged from the interviews included traumatic birthing experience, wondering and waiting, and experiencing surgery. CONCLUSION: All families should receive support and acknowledgement of the widespread impact of OBPI.

HISTORIQUE: La lésion obstétricale du plexus brachial (LOPB) chez les enfants peut susciter une grande détresse dans une famille en raison de l'incertitude quant au rétablissement, de la variabilité du rétablissement spontané et du caractère flou des indicateurs de chirurgie. OBJECTIF: Examiner les répercussions d'un enfant ayant une LOPB sur la famille et si l'échelle IoFS des répercussions sur les membres de la famille peut contribuer à répondre à leurs inquiétudes. MÉTHODOLOGIE: Une méthodologie mixte (étude transversale et entrevues semi-structurées) a été privilégiée. RÉSULTATS: Trente-huit familles d'enfants ayant une LOPB ont rempli l'échelle IoFS. La chirurgie prédisait de manière significative un indice d'IoFS total plus élevé (P=0,02). L'association entre l'indice total et la gravité ou l'âge n'était pas significative. Les répercussions sur la famille ne dépendraient donc pas de ces facteurs. Les thèmes qui ont émergé des entrevues incluaient une expérience d'accouchement traumatisante, de l'inquiétude et de l'attente et l'expérience de la chirurgie. CONCLUSION: Toutes les familles devraient recevoir du soutien, et les effets généralisés de la LOPB sur leur état devraient être pris en compte.

Limb length differences after obstetrical brachial plexus injury: a growing concern.

BACKGROUND: Residual size discrepancy between the affected and unaffected limbs is a distinct but not well-understood consequence of an obstetrical brachial plexus injury. This study aimed to document the extent of limb length differences in children with obstetrical brachial plexus injury compared with typically developing children. The effects of age, growth patterns, severity, and surgical intervention were also explored. Also, this study examined the reliability of the clinical measurement technique. METHODS: A prospective cohort of 179 children with obstetrical brachial plexus injury was systematically evaluated for limb length and girth by a multidisciplinary team. Clinical measurements were obtained at regular intervals until 12 months and then yearly. A control group of typically developing children aged 6 months to 17 years had limb length and girth measured on one occasion. RESULTS: Interrater reliability of clinical measurement techniques demonstrated high consistency, with an intraclass correlation of 0.90 (p < 0.0001). Limb measurements were recorded at nine time points. Paired t tests of children with and without surgical intervention found significant differences between affected and unaffected sides in arm, forearm, and total length as early as the 1-month measurement and at most other time points (p < 0.05). The 3-month total limb length difference was a statistically significant predictor of 12-month limb length difference (p < 0.05). CONCLUSIONS: Obstetrical brachial plexus injury significantly affects the length of the arm and forearm. Early detectable limb length deficits are associated with the likelihood of requiring surgical reconstruction. Clinical limb length measurement can be performed reliably and noninvasively.

Navigating the gray zone: a guideline for surgical decision making in obstetrical brachial plexus injuries.

OBJECT: In the literature, the best recommendations are imprecise as to the timing and selection of infants with obstetrical brachial plexus injury (OBPI) for surgical intervention. There is a gray zone (GZ) in which the decision as to the benefits and risks of surgery versus no surgery is not clear. The authors propose to describe this category, and they have developed a guideline to assist surgical decision-making within this GZ. METHODS: The authors first performed a critical review of the medical literature to determine the existence of a GZ in other clinical publications. In those reports, 47-89% of infants with OBPI fell within such a GZ. Complete recovery in those reported patients ranged from 9 to 59%. Using a prospective inception cohort design, all infants referred to the OBPI Clinic at McMaster Children's Hospital were systematically evaluated up to 3 years of age. The Active Movement Scale scores were compared for surgical and nonsurgical groups of infants in the GZ to identify any important trends that would guide surgical decision-making. RESULTS: In the authors' population of infants with OBPI, 81% fell within the GZ, of whom 44% achieved complete recovery. Mean scores differed significantly between surgery and no surgery groups in terms of total Active Movement Scale score and shoulder abduction and flexion at 6 months. Elbow flexion and external rotation differed at 3 months. CONCLUSIONS: There is compelling evidence that there is a group of infants with OBPI in whom the assessment of the risk/benefit ratio for surgical versus nonsurgical treatment is not evident. These infants reside within what the authors have called the GZ. Based on their results, a guideline was derived to assist clinicians working with infants with OBPI to navigate the GZ.

Botulinum toxin as an adjunct to motor learning therapy and surgery for obstetrical brachial plexus injury.

Following obstetrical brachial plexus injury, infants are unable to learn specific patterns of movement due to the disruption of neural pathways. Even with successful reinnervation (spontaneously or post surgical reconstruction), function can be suboptimal due to overactivity in antagonist muscles preventing movement of reinnervated muscles. Botulinum toxin type A (BTX-A) was used to temporarily weaken antagonistic muscles early in the reinnervation process following brachial plexus injury, with the aim of facilitating functional improvement. A case series of eight children (five females, three males; mean age 12.5mo [SD 6.43]; range 5-22mo) with significant muscle imbalances but evidence of reinnervation were given BTX-A injections into the triceps, pectoralis major, and/or latissimus dorsi muscles. After a single injection, all parents reported improvement in function. Active Movement Scale total score changed significantly between pre BTX-A and 1 month (p=0.014), and 4 months (p=0.022) post BTX-A injection. It is proposed that BTX-A facilitated motor learning through improved voluntary relaxation of antagonist muscles while allowing increased activity in reinnervated muscles.