Biomechanics of Brachial Plexus Injuries Due to Shoulder Dystocia.

Mathematic modeling of forces associated with shoulder dystocia: A comparison of endogenous and exogenous sources

Risk factors for brachial plexus injury with and without shoulder dystocia

Traumatic brachial plexus injuries are a devastating injury that results in partial or total denervation of the muscles of the upper extremity. Treatment options that include neurolysis, nerve grafting, or neurotization (nerve transfer) has become an important procedure in the restoration of function in patients with irreparable preganglionic lesions. Restoration of elbow flexion is the primary goal in treating patients with severe brachial plexus injuries. Nerve transfers are used when spinal roots are avulsed, and proximal stumps are not available. In the present study, we analyze the results obtained in 20 patients treated with phrenic-musculocutaneous nerve transfer to restore elbow flexion after brachial plexus injuries. A consecutive series of 25 adult patients (21 men and 4 women) with a brachial plexus traction/crush lesion were treated with phrenic-musculocutaneous nerve transfer, but only 20 patients (18 men and 2 women) were followed and evaluated for at least 2 years postoperatively. All patients had been referred from other institutions. At the initial evaluation, eight patients received a diagnosis of C5-6 brachial plexus nerve injury, and in the other 12 patients, a complete brachial plexus injury was identified. Reconstruction was undertaken if no clinical or electrical evidence of biceps muscle function was seen by 3 months post injury. Functional elbow flexion was obtained in the majority of cases by phrenic-musculocutaneous nerve transfer (14/20, 70%). At the final follow-up evaluation, elbow flexion strength was a Medical Research Council Grade 5 in two patients, Grade 4 in four patients, Grade 3 in eight patients, and Grade 2 or less in six patients. Transfer involving the phrenic nerve to restore elbow flexion seems to be an appropriate approach for the treatment of brachial plexus root avulsion. Traumatic brachial plexus injury is a devastating injury that result in partial or total denervation of the muscles of the upper extremity. Treatment options include neurolysis, nerve grafting, or neurotization (nerve transfer). Neurotization is the transfer of a functional but less important nerve to a denervated more important nerve. It has become an important procedure in the restoration of function in patients with irreparable preganglionic lesions. Restoration of elbow flexion is the primary goal in treating patients with severe brachial plexus injuries. Nerve transfers are used when spinal roots are avulsed, and proximal stumps are not available. Newer extraplexal sources include the ipsilateral phrenic nerve as reported by Gu et al. (Chin Med J 103:267-270, 1990) and contralateral C7 as reported by Gu et al. (J Hand Surg [Br] 17(B):518-521, 1992) and Songcharoen et al. (J Hand Surg [Am] 26(A):1058-1064, 2001). These nerve transfers have been introduced to expand on the limited donors. The phrenic nerve and its anatomic position directly within the surgical field makes it a tempting source for nerve transfer. Although not always, in cases of complete brachial plexus avulsion, the phrenic nerve is functioning as a result of its C3 and C4 major contributions. In the present study, we analyze the results obtained in 20 patients treated with phrenic-musculocutaneous nerve transfer to restore elbow flexion after brachial plexus injuries.

Treatment of a rotator cuff tear with concomitant complete brachial plexopathy after glenohumeral dislocation: a case report

This article reports a series of severe permanent brachial plexus injuries in American football players. The authors describe the mechanisms of injury and outcomes from a more contemporary treatment approach in the form of nerve transfer tailored to the specific injuries sustained. Three cases of nerve transfer for brachial plexus injury in American football players are discussed in detail. Two of these patients regained functional use of the extremity, but 1 patient with a particularly severe injury did not regain significant function. Brachial plexus injuries are found along a spectrum of brachial plexus stretch or contusion that includes the injuries known as "stingers." Early identification of these severe brachial plexus injuries allows for optimal outcomes with timely treatment. Diagnosis of the place of a given injury along this spectrum is difficult and requires a combination of imaging studies, nerve conduction studies, and close monitoring of physical examination findings over time. Although certain patients may be at higher risk for stingers, there is no evidence to suggest that this correlates with a higher risk of severe brachial plexus injury. Unfortunately, no equipment or strengthening program has been shown to provide a protective effect against these severe injuries. Patients with more severe injuries likely have less likelihood of functional recovery. In these patients, nerve transfer for brachial plexus injury offers the best possibility of meaningful recovery without significant morbidity. [ Orthopedics. 2016; 39(6):e1188-e1192.].

Perinatal brachial plexus palsy (PBPP) is a flaccid paralysis of the arm at birth that affects different nerves of the brachial plexus supplied by C5 to T1 in 0.42 to 5.1 infants per 1000 live births. To identify antenatal factors associated with PBPP and possible preventive measures, and to review the natural history as compared with the outcome after primary or secondary surgical interventions. A literature search on randomized controlled trials, systematic reviews and meta-analyses on the prevention and treatment of PBPP was performed. EMBASE, Medline, CINAHL and the Cochrane Library were searched until June 2005. Key words for searches included 'brachial plexus', 'brachial plexus neuropathy', 'brachial plexus injury', 'birth injury' and 'paralysis, obstetric'. There were no prospective studies on the cause or prevention of PBPP. Whereas birth trauma is said to be the most common cause, there is some evidence that PBPP may occur before delivery. Shoulder dystocia and PBPP are largely unpredictable, although associations of PBPP with shoulder dystocia, infants who are large for gestational age, maternal diabetes and instrumental delivery have been reported. The various forms of PBPP, clinical findings and diagnostic measures are described. Recent evidence suggests that the natural history of PBPP is not all favourable, and residual deficits are estimated at 20% to 30%, in contrast with the previous optimistic view of full recovery in greater than 90% of affected children. There were no randomized controlled trials on nonoperative management. There was no conclusive evidence that primary surgical exploration of the brachial plexus supercedes conservative management for improved outcome. However, results from nonrandomized studies indicated that children with severe injuries do better with surgical repair. Secondary surgical reconstructions were inferior to primary intervention, but could still improve arm function in children with serious impairments. It is not possible to predict which infants are at risk for PBPP, and therefore amenable to preventive measures. Twenty-five per cent of affected infants will experience permanent impairment and injury. If recovery is incomplete by the end of the first month, referral to a multidisciplinary team is necessary. Further research into prediction, prevention and best mode of treatment needs to be done.

Injuries associated with serious brachial plexus involvement in polytrauma among patients requiring surgical repair

Shoulder dystocia outcomes associated with structured prenatal counseling

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We aimed to analyze the risk factors for clavicle fractures in newborns with shoulder dystocia and brachial plexus injury and to determine whether their incidence is associated with local characteristics. This study was conducted as a retrospective trial between January 2017 and December 2018. Patients with clavicular fracture who were hospitalized in the neonatal intensive care unit of a community hospital were retrospectively analyzed. The clavicular fracture cohort was first divided into two groups and then two subgroups: patients with/without shoulder dystocia and patients with/without a brachial plexus injury. Peripartum and neonatal risk factors of these patients were reviewed using the patient information system. Any additional neurological or musculoskeletal trauma was noted. A multivariate logistic regression analysis was performed to determine independent predictors of shoulder dystocia and brachial plexus injury. A total of 46 patients with shoulder dystocia in 25 (54%) and brachial plexus injury in 12 (26%) were included in the study. The birth weight of patients with shoulder dystocia was 4,164.2±412.7 g, and that of patients without was 3,535.8±865.2 g (p=0.003). In 11 of 14 patients (44%) in whom labor was induced and whose infant had a fractured clavicle, the infant also had shoulder dystocia (p=0.029). Brachial plexus injury was found in 8 (66.7%) of 14 infants who were born by induced labor and who had a clavicular fracture (p=0.002). The regression analysis revealed that age and induction of labor were independent risk factors for brachial plexus injury (odds ratio=1.599 and 81.862, respectively). Gestational weight gain (p=0.003) and neonatal birth weight (p=0.047) were also found as independent risk factors for shoulder dystocia. Evidence from this study has shown that not only birth age or birth weight but also excessive weight gain by mother and induction of labor may increase the risk of clavicula fracture with brachial plexus palsy. Advanced maternal age, multiparity, and deliveries after 39 weeks seem to be risk factors for a clavicular fracture with a brachial plexus injury. Level IV, Therapeutic study.

Brachial plexus deficits with and without shoulder dystocia

Obstetric brachial plexus palsy (OBPP), is an injury of the brachial plexus at childbirth affecting the nerve roots of C5-6 (Erb-Duchenne palsy-nearly 80% of cases) or less frequently the C8-T1 nerve roots (Klumpke palsy). OBPP often has medicolegal implications. In the United Kingdom and the Republic of Ireland the incidence is 0.42, in the United States 1.5, and in other western countries 1 to 3 per 1000 live births. Most infants with OBPP have no known risk factors. Shoulder dystocia increases the risk for OBPP 100-fold. The reported incidence of OBPP after shoulder dystocia varies widely from 4% to 40%. Other risk factors include birth weight >4 kg, maternal diabetes mellitus, obesity or excessive weight gain, prolonged pregnancy, prolonged second stage of labor, persistent fetal malposition, operative delivery, and breech extraction of a small baby. OBPP after caesarean section accounts for 1% to 4% of cases. Historically, OBPPs have been considered to result from excessive lateral traction and forceful deviation of the fetal head from the axial plane of the fetal body, usually in association with shoulder dystocia, which increases the necessary applied peak force and time to deliver the fetal shoulders. Direct compression of the fetal shoulder on the symphysis pubis may also cause injury. However a significant proportion of OBPPs occurs in utero, as according to some studies more than half of the cases are not associated with shoulder dystocia. Possible mechanisms of intrauterine injury include the endogenous propulsive forces of labor, intrauterine maladaptation, or failure of the shoulders to rotate, and impaction of the posterior shoulder behind the sacral promontory. Uterine anomalies, such as fibroids, an intrauterine septum, or a bicornuate uterus may also result in OBPP. It is not possible to reliably predict which fetuses will experience OBPP. Future research should be directed in prospective evaluation of the mechanisms of injury, to enable obstetricians, midwives, and other health care professionals to identify modifiable risk factors, develop preventive strategies, and improve perinatal outcomes. Obstetricians & Gynecologists, Family Physicians. After completion of this article, the reader will be able to summarize known risk factors for shoulder dystocia, describe the relationship between shoulder dystocia and obstetrics brachial plexus injuries, and describe three potentail explanantions for brachial plexus injuries other than lateral traction at delivery.

Abstracts

We have studied the causes and outcome of obstetric brachial plexus palsy in all children born in Malmö during the 10-year period 1973-1982. Forty-eight of 25,736 live-born children (0.19%) were neonatally diagnosed as having a brachial plexus paresis. Twenty-five percent of these, i.e., one child in 2,000 liveborn, had a persistent palsy. The obstetric history was characterized by high birthweight, vertex presentation with shoulder dystocia and multiparity; and in two cases the mother had two children with brachial palsy. The children who recovered totally did so during the first few months. The prognosis for the more common upper brachial plexus, or Erb's, was more favorable than that for entire brachial plexus palsy. All the children with persistent palsy were afflicted with considerable reduction in arm function, resulting in varying degrees of handicap, such as not being able to use the palsied arm at all or not being able to perform certain tasks--writing properly, playing a musical instrument, doing the hair, wearing clothing with shoulder straps, etc. We wish to point out that, in several cases, obstetric brachial plexus palsy results in a lifelong handicap and that prevention and therapy are essential both in obstetric and in pediatric management.

BackgroundCaesarean section (CS) is widely perceived as protective against obstetric brachial plexus injury (BPI), but few studies acknowledge the factors associated with such injury. The objectives of this study were therefore to aggregate cases of BPI after CS, and to illuminate risk factors for BPI.MethodsPubmed Central, EMBASE and MEDLINE databases were searched using free text: (“brachial plexus injury” or “brachial plexus injuries” or “brachial plexus palsy” or “brachial plexus palsies” or “Erb’s palsy” or “Erb’s palsies” or “brachial plexus birth injury” or “brachial plexus birth palsy”) and (“caesarean” or “cesarean” or “Zavanelli” or “cesarian” or “caesarian” or “shoulder dystocia”). Studies with clinical details of BPI after CS were included. Studies were assessed using the National Institutes for Healthy Study Quality Assessment Tool for Case Series, Cohort and Case-Control Studies.Main results39 studies were eligible. 299 infants sustained BPI after CS. 53% of cases with BPI after CS had risk factors for likely challenging handling/manipulation of the fetus prior to delivery, in the presence of considerable maternal or fetal concerns, and/or in the presence of poor access due to obesity or adhesions.ConclusionsIn the presence of factors that would predispose to a challenging delivery, it is difficult to justify that BPI could occur due to in-utero, antepartum events alone. Surgeons should exercise care when operating on women with these risk factors.