Case study: brachial plexus

Introduction 

The brachial plexus is a network of nerves that exit the spinal cord from the lower four cervical (neck) spinal roots and the first thoracic root. These travel beneath the collar bone surrounding the axillary artery which becomes the brachial artery (the principal blood supply to the arm) before reaching the arm, providing both movement and sensation. Each spinal root level (C5, C6, C7, C8 and T1) is relatively consistent in terms of the nerves derived from it, which muscles it moves and which areas of skin it gives sensation to. Therefore, careful examination can help to determine the location of any injury. 

Obstetric brachial plexus injury (OBPI) is an injury to these nerves at a level between the spinal cord and the shoulder.  It occurs in the newly born child. It is generally considered to be a result of birth related trauma, such as shoulder dystocia, although this view is somewhat controversial. The condition is referred to by various other terms including obstetric brachial plexus palsy, neonatal brachial plexus injury, Erb’s or Erb-Duchenne palsy (when not complete) and birth-related brachial plexus injury. Generally, the upper parts of the brachial plexus (affecting shoulder and elbow function) are primarily affected, with the wrist and the hand being affected in fewer cases. The majority of cases will resolve completely and do not require surgical intervention. 

The management and treatment of shoulder dystocia is also controversial and varies both between and within countries. This reflects the variability of the prognosis, and the difficulty in conducting useful clinical trials. However, recognition of the importance of surgical intervention in cases of severe injury, therapy exercises, and a multidisciplinary approach are universally recognised.  

Surgery for children with this injury can be divided into early primary nerve reconstruction, which usually takes place by the age of one year old, and later musculoskeletal reconstruction of the shoulder, elbow, wrist and/or hand. One of the reasons for secondary surgery is that when lack of nerve input prevents correct development of the muscles, the resulting abnormal dynamics in the bones of the upper limb causes contractures and alters the shape and function of joints. This is especially common in the shoulder. 

While surgery can offer significant improvements in quality of life for children with OBPI, those affected enough to require surgery rarely make a complete recovery. Nonetheless, with adequate support, they can go on to lead good quality, fulfilled lives. 

Functional assessment of OBPI can be performed by a variety of techniques. The Active Movement Score is suitable for children under the age of 4 years and the Brachial Plexus Outcome Measure is used in older children. 

A scar is a wound that has healed in such a way that it is non-identical to the neighbouring tissue. Scarring is a normal, necessary physiological process following injuries, and is not usually a problem. We all have scars. A skin scar becomes an issue if it is uncomfortable or painful, unstable (where healing does not progress normally and wound breakdown and ulceration result), abnormal (stretched, hypertrophic or keloid), or causes a contracture (when it constrains movement). A scar may also be a problem if it has psychological effects on the patient. Physical evaluation of a scar can be performed using the Vancouver Scar Scale validated assessment tool which rates the scar according to the vascularity, pigmentation, pliability and height. It is rated out of 13, where 0 is essentially an imperceptible scar and 13 is an obvious and “severe” scar. 

Case Presentation 

Patient history and demographics 

Patient A is an eight-year-old girl. After an unremarkable pregnancy, she was delivered via Kiwi forceps delivery, due to shoulder dystocia. She subsequently developed Erb’s palsy on the left side; her left arm was hypertonic and floppy. No other unusual findings were noted. She held her left arm in an adducted and pronated position and no muscle contractions could be felt on movement of the shoulder, although elbow flexion and extension did cause some contraction of the muscles. Hand grip was good, and all of the joints of the left arm were supple with symmetrical passive movement. The right arm appeared normal. Three months later, apart from a very mild improvement in the range of abduction in the left shoulder, the clinical picture remained similar.  

Four month’s later, Patient A received a diagnosis of obstetric brachial palsy Narakas group II left side shoulder dysplasia with obligate internal rotation. The potential need for surgical intervention was identified. However, as EMGs taken showed good nerve recovery and examination of the shoulder identified no restriction to passive external rotation, conservative management consisting chiefly of physical therapy was recommended at this time. The range of shoulder movement was maintained over the next year, although external rotation did not improve.  

At the age of 18 months, Patient A’s shoulder had become significantly tighter and the decision was taken to intervene with an anterior shoulder release. Latissimus dorsi transfer was deferred as it might prove unnecessary. The surgery was performed and a Spica cast was applied for 6 weeks. There were no peri-operative complications, and the patient recovered well. At an annual review, Patient A was reported to have an excellent range of active and passive external rotation. Residual abnormality of movement was thought to be due to habitual motor learning rather than weakness. Some capsular tightness was noted around the shoulder.  

At a follow-up appointment when Patient A was four years of age, the shoulder tightness remained. Passive external rotation was good but Patient A was unable to actively externally rotate. As she was able to perform hand to mouth movements normally when shown, surgical correction was deferred in preference for physiotherapy treatment that really focused on active external rotation in adduction. However, after several months, it was clear that active external rotation had not returned, and surgical intervention was now indicated.  

The result of this surgery was reported as good, but the patient was unable to see a physiotherapist due to COVID-19 staffing levels.  

Clinical findings

When examined at 7 years of age, no abnormality was reported in Patient A’s right arm. Examination of the left arm revealed some narrowing of the shoulder girdle and mild underdevelopment of the upper limb. The left scapula was a little smaller and sitting a little higher than on the right, and well-healed surgical scars were visible to the front and back of the left shoulder. No swelling or tenderness was apparent on palpation and the location of the joints appeared normal. The left limb had a reduced range of movement, which was particularly apparent for combined abduction and internal rotation. In addition, the left limb strength was reduced and the grip strength in the left hand compared to the right was reduced by 25-30% after taking hand dominance into account. No spinal curvature was noted although Patient A’s posture looked slightly tipped due to the difference in scapulae sizes. Appreciable scapular protraction due to dorsal capsular tightness was noted.  

At examination at age 8, it was noted that most of Patient A’s current problems related to putting on clothing and sporting activities, particularly when throwing a ball.

These are the result of the problems with the left shoulder. She is not able to carry as much weight with the left hand as with the right. No issues with school, helping with household chores, or playing were reported, nor was pain. Although overall shoulder function is reasonable, the apparent ‘shrugging’ of the shoulder is actually caused by abduction contracture of the shoulder joint and is a very common finding in obstetric brachial plexus injury. Sensory testing showed a very slight loss of sensation in the thumb side of the left hand. Patient A felt that her arm worked better than her hand, although objective assessment suggested the opposite to be true. Intervention to the two surgical scars on the patient’s shoulder was deemed unnecessary, given that no issues were reported.  

Treatment and management 

Patient A has received regular physiotherapy treatment, approximately every 6 weeks, starting shortly after birth. She has also undergone two surgical procedures, aimed at improving the range of movement in the damaged shoulder.  

Legal aspects related to the case 

The Hospital Trust has admitted that a breach of duty caused Patient A’s injury. There was a negligent failure to discuss the delivery options with her mother. The circumstances surrounding the birth indicatethat these discussions would have included the option of a Caesarean delivery, which would itself have been associated with significant risks, given the mother’s high body mass index. However, Patient A’s mother maintains that, despite the risks, she would have chosen a Caesarean delivery and therefore the subsequent brachial plexus injury would have been avoided.  

The medical records do not contain a definitive description of the manoeuvre used to achieve delivery of Patient A’s shoulders. 

In the absence of extraordinary maternal forces, on a balance of probabilities, it is likely that inappropriate traction was used, and this was the cause of the injury sustained by Patient A.  

The defendant has not admitted the extent of the injury, or the loss or damage associated with it at this stage.  

The treatment received by Patient A after her injury has been appropriate.  

Patient A fulfils the criteria of the Equality Act 2010 and can therefore be classified as disabled.  

Expert opinion 

Causation 

Patient A’s injury is most likely to be an upper brachial plexus injury extending between C5 and C6 or C7. It is reasonable to assume that this is an obstetrical injury associated with her birth and that the surgery and subsequent scarring became necessary because of this injury.  

Prognosis

Patient A’s long-term prognosis can be largely predicted from her present condition. There is unlikely to be a substantial change in the range of motion of the shoulder, although it may become tighter as it grows. The percentage reduction in strength will remain. The cosmetic abnormality will become somewhat more noticeable as the limb grows.  

Patient A is at risk of shoulder dysplasia in the future, which may then increase the risk of degenerative arthritis in the left shoulder. However, this risk is countered by the weakness, stiffness and underuse of the upper limb. An MRI scan and review when Patient A is a teenager will aid in further assessment of this risk. As Patient A grows, there will be structural changes in the shoulder and her own view of her function, and how it relates to her career aspirations, may change.  

Currently, Patient A is not worried by the scars on her left shoulder. However, some children go on to develop psychological issues in adolescence relating to dysfunction in body image and this may be the case here.  

Therefore, Patient A is unlikely to be able to undertake heavy manual activities due to the limitations in the left upper limb. Certain careers, such as the military, law enforcement or personal trainer, will probably be closed to her.  

Treatment plan

Stretches have been recommended to treat the posterior shoulder tightness currently seen, which is limiting internal rotation. Physical therapy would be best provided by a therapist with specialist experience of OBPI. If this is insufficient, surgical posterior shoulder release should be considered but is unlikely to make a major functional difference. The outcome of any surgery cannot be fully assessed until a year after the procedure.  

An MRI scan would be useful to identify the presence of shoulder dysplasia, which could impact both treatment and prognosis.  

Patient A should be reviewed on a yearly basis.   

Conclusion 

Outcome 

Patient A has recovered well from the two surgical procedures she has undergone. Although left with scars, these do not bother her at present. However, this situation may change as she enters her teenage years, when body image becomes more important. The long-term outcome of this case will not be known until Patient A is at least 15 years of age.  

Discussion 

Patient A was an unusually large baby and shoulder dystocia was noted during her delivery. Despite this, her mother was not given the option of a Caesarean section, and she was delivered by forceps, although the exact technique used was not recorded. Shortly afterwards, dysfunction of the left arm was noted. She was subsequently diagnosed with OBPI to the left shoulder.  

Although the range of movement improved somewhat following conservative treatment consisting of regular physiotherapy, Patient A has also undergone two surgical procedures aimed at improving the function of the left arm, particularly the shoulder. These have been partially successful, but the movement of the left upper limb is still restricted and will probably not fully resolve. Because of this, certain activities and careers will not be possible.

As Patient A is still a relatively young child, it is not possible to accurately predict the final prognosis for this injury.   

Aspects of this case relating to clinical negligence 

Patient A’s mother reported a history of shoulder dystocia when she was born. Furthermore, Patient A weighed 12lbs when born, which is a very large birth weight. These two factors should have indicated the possibility of problems during delivery. A discussion with the mother, including the option of a Caesarean section, should then have taken place.  

Details of the exact procedure used to deliver Patient A were not recorded.