Obstetric Brachial Plexus Palsy (OBPP)

What is obstetric brachial plexus palsy?

It is an injury to the nerves that provide movement and sensation to the upper limb. The injury usually occurs during childbirth due to mechanical traction on the newborn’s neck and shoulder.

The brachial plexus is a network of nerves arising from the neck (roots C5–T1) and extending to the arm. In certain difficult deliveries, attempts to release the shoulder or fetal positioning can exert excessive traction on these nerves, resulting in:

• simple stretch injury (neurapraxia) with a high likelihood of spontaneous recovery,
• neuroma in continuity (scarred reorganization of the nerve with partial conduction),
• rupture of the nerve distal to the dorsal root ganglion (postganglionic),
• avulsion of the nerve root from the spinal cord, the most severe form of injury.

Clinically, the newborn presents with weakness or complete paralysis of the affected upper limb, with characteristic postures depending on which segments of the plexus are involved.

How common is it & what are the main risk factors?

Obstetric brachial plexus palsy is relatively uncommon, occurring in approximately 1 in 1,000 births, with frequency varying by country and obstetric practices.

Factors most often associated with OBPP include:

• High birth weight (macrosomia), particularly in infants of mothers with gestational diabetes.
• Shoulder dystocia, when the shoulder becomes impacted in the pelvis during vaginal delivery.
• Prolonged second stage of labor or difficult vaginal delivery.
• Breech presentation, especially in low-birth-weight infants – increasing the risk of traction injury.
• Use of forceps or vacuum extraction during difficult assisted deliveries.
• Multiparity, cephalopelvic disproportion, and other obstetric factors.

Importantly, injury may occur even without overtly forceful obstetric maneuvers or after cesarean section. For this reason, management focuses on the care of the newborn rather than attribution of causality.

How does it occur – what happens to the nerves?

The essence of the injury is excessive stretching of the nerve roots C5–T1 between the neck and shoulder, beyond their normal elastic limits.

At the level of the nerve, three main types of injury can be distinguished:

• Neuroma in continuity – the nerve has not been completely transected, but traumatic scar tissue develops among “entangled” axons. Some degree of electrical conduction persists along the nerve, with potential for partial recovery.
• Traumatic rupture – complete transection of the nerve distal to the dorsal root ganglion (postganglionic). There is no continuity with the proximal root and surgical reconstruction with grafts is required.
• Preganglionic avulsion – detachment of the root from the spinal cord. Direct nerve repair is not possible; nerve transfers are the main reconstructive option.

Whether regenerating nerve fibers reach the denervated muscles in time and in the correct pattern is the principal determinant of long-term functional outcome.

How does it present and what types of palsy exist (Erb, total, Klumpke, Narakas)?

Presentation ranges from partial weakness to flaccid paralysis of the entire upper limb with associated Horner syndrome.

The classic classification is the Narakas classification:

• Group I: C5–C6 injury (classic Erb palsy) – paralysis of shoulder and elbow.
• Group II: C5–C7 – paralysis of shoulder, elbow, and wrist/finger extension.
• Group III: total brachial plexus palsy (C5–T1) – a “flail” upper limb.
• Group IV: total palsy + Horner syndrome (miosis, ptosis, anhidrosis) – suggests a high likelihood of avulsion.

Characteristic clinical patterns include:

• Erb palsy (upper lesion C5–C6/7): shoulder adducted and internally rotated, elbow extended, forearm pronated, wrist/fingers flexed – the classic “waiter’s tip” posture.
• Klumpke palsy (lower lesion C8–T1): predominant hand and intrinsic muscle paralysis, sensory disturbance along the ulnar aspect of the limb.
• Total palsy: complete absence of movement from shoulder to fingers, often accompanied by Horner syndrome.

In everyday clinical practice, the pattern of involvement guides prognosis and surgical decision-making.

How is the clinical assessment performed in the first months of life?

The first 6 months are critical. Systematic clinical examination is the most reliable tool—more informative than any single investigation.

At each visit we assess:

• Spontaneous movement of the affected upper limb compared with the healthy side.
• Neonatal reflexes (Moro, asymmetric tonic neck reflex, etc.).
• Elbow flexion strength against gravity – a key prognostic indicator.
• Shoulder motion: external rotation and abduction, glenohumeral stability.
• Passive range of motion and any contractures/stiffness of shoulder, elbow, or wrist.

In infants who regain antigravity strength at the shoulder and elbow within 2–3 months, the likelihood of near-complete functional recovery by 2 years of age is high. Conversely, persistent weakness beyond 4–6 months markedly increases the risk of permanent deficit and raises the indication for surgical evaluation.

What investigations may be required (MRI, myelography, EMG)?

Imaging and electrophysiological studies are adjunctive—they do not replace clinical assessment.

Possible diagnostic tools include:

• MRI of the cervical spine & brachial plexus – may demonstrate pseudomeningoceles, absent roots, nerve course, and shoulder joint development.
• CT myelography – in specialized centers, may depict root avulsion in greater detail, particularly through absence of rootlets within a pseudomeningocele.
• Electromyography (EMG) – of limited but not negligible value:
  • early (around 1 month), absence of activity in specific muscles may indicate severe injury,
  • around 3 months, findings may be misleading due to aberrant axonal reinnervation.
• Shoulder ultrasound – to assess glenohumeral joint development in young infants.

At Neuroknife, decisions regarding operative management are never based on a single test, but on the integration of clinical findings, imaging, and evolution over time.

What is the natural history & prognosis?

Approximately 60–80% of infants show substantial or near-complete improvement over time, while 20–30% are left with a permanent deficit.

General prognostic principles:

• Early return of elbow flexion within 3 months correlates with much better final function.
• Lack of meaningful improvement after 4–6 months increases the likelihood of a permanent neurological deficit.
• Total palsies (Narakas III–IV) carry the poorest prognosis.
• Presence of Horner syndrome usually indicates avulsion and a worse outcome.

For families, it is important to understand that even when a permanent deficit exists, the appropriate combination of surgical treatment, physiotherapy, occupational therapy, and orthopedic interventions enables many children to achieve excellent functional use of the arm in everyday activities.

What is conservative management & the role of physiotherapy?

Treatment begins in the first weeks of life. Even when surgery is being considered, rehabilitation does not wait.

Main components of conservative management:

• Parental education in gentle passive movements, handling of the infant, and avoidance of pain.
• Physiotherapy aimed at:
  • maintaining full passive range of motion of shoulder–elbow–wrist–fingers,
  • preventing contractures and joint stiffness and glenohumeral dysplasia,
  • strengthening recovering muscles with age-appropriate exercises.
• Occupational therapy to integrate the affected limb into play and daily activities.
• Splints in selected cases to prevent deformities (e.g., wrist hyperextension, shoulder rotational deformities).

The outdated practice of complete immobilization of the limb has been abandoned: it does not prevent nerve injury and increases the risk of joint problems. Movements within a normal, pain-free range are safe and beneficial.

When is surgical reconstruction of the brachial plexus indicated?

The decision for surgery is highly individualized and ideally made in a specialized brachial plexus center.

General criteria that raise concern and prompt surgical evaluation include:

• Absence of adequate elbow flexion at 3–4 months, particularly in Narakas II–IV.
• Total upper limb paralysis (Narakas III–IV) without clear improvement in the early months.
• Presence of Horner syndrome or strong suspicion of avulsion.
• Infants with severe hand/finger involvement with minimal or no recovery.

In general, if significant functional deficit persists by 6 months, the risk of permanent disability increases and microsurgical reconstruction should be seriously considered. In some severe total palsies, referral occurs earlier (1–3 months).

What types of surgical procedures are performed?

The goal of surgery is to “deliver new, healthy nerve input” to critical muscles (shoulder, elbow) as early as possible, preserving the potential for functional recovery.

Principal categories of microsurgical procedures:

• Neurorrhaphy & nerve grafting (e.g., sural nerve grafts) to reconstruct ruptured postganglionic roots or trunks of the plexus.
• Nerve transfers, such as:
  • spinal accessory nerve → suprascapular nerve (shoulder),
  • median/ulnar or intercostal branches → musculocutaneous nerve (elbow flexion),
  • other extraplexal donors to key target muscles.
• External neurolysis – release of a neuroma in continuity when partial function persists.

Later in childhood, secondary orthopedic procedures (tendon transfers, shoulder or humeral osteotomies) may be required to improve alignment and range of motion, particularly after severe initial injuries.

How is long-term follow-up organized & what is the role of orthopedics?

Obstetric brachial plexus injury is not “cured” by surgery alone—it requires long-term care and rehabilitation.

Long-term follow-up includes:

• Regular neurological/neurosurgical assessments in infancy and early childhood (initially every 1–3 months, later less frequently).
• Close collaboration with pediatric orthopedics to monitor glenohumeral development, prevent shoulder dislocation, and address rotational deformities.
• Continuation of physiotherapy & occupational therapy with age-appropriate goals.
• Functional assessment (dressing, self-care, participation in play and sports).
• Psychological and educational support when needed, ensuring that differences in arm function do not translate into reduced self-confidence.