Obstetrical Brachial Plexus Palsy is due to excessive traction on the brachial plexus during childbirth seen in 2 per 1000 births.
Eg. By pulling the baby’s head away from the shoulder or by exerting traction with the baby’s arm in abduction
Progressive glenoid hypoplasia occurs in 70 % of children with significant internal rotation contracture
Miller’s Review of Orthopaedics 8th Edition
Risk factors
- Diabetic mother
- Large for date babies, force delivery, breech presentation, prolonged labor
Narakas classification
| Group 1 | C5/C6 | Abductors + ERs of shoulders + Supinators are paralyzed |
| Group 2 | C5/C6/C7 | Wrist and digital extensors are also paralyzed by weak or absent tricep function |
| Group 3 | Entire plexus involved | Flaccid paralysis (finger paralysis is 1st to recover) |
| Group 4 | Entire plexus with horner’s sign | Flaccid paralysis +Horner’s sign |
Horner’s syndrome with the presence of eyelid ptosis and pupillary miosis suggests avulsion of lower brachial plexus
Clinical Features
Floopy/ Flail arm after delivery (day 1, 2, or later)
Erb-Duchenne Palsy
- C5, C6 +/- C7
- Arms held by side, internally rotated and pronated
- Loss of finger extension can be present
- Abductors, External rotators, and supinators are paralyzed
- Best prognosis and most common
Klumpe’s Palsy
- C8 and T1
- Arm supinated + elbow flexed
- Loss of intrinsic muscle power in hand
- Absent reflexes
- Horner’s syndrome: Unilateral
- Poor prognosis
Total Plexus Injury
- Baby’s arm in flail and pale
- All finger muscles are paralyzed
- Vasomotor involvement + unilateral horners syndrome
- Worst prognosis
Sympathetic outflow in babies also encompasses C8 as well as T1, Unlike in adults
Management
Xrays are done
- Should exclude fractures of the shoulder or the clavicle
- Position of the humeral head within the glenoid
Observation
Next few weeks
More than 90% cases eventually improves without intervention
Miller’s Review of Orthopaedics 8th Edition
Operative treatment
Upper brachial plexus avulsion injuries cause impairment of shoulder and elbow function which is very disabling for patients.
Restoration of elbow flexion is the first goal to be achieved in order to restore arm function
Early surgery is to address nerve function, and late surgery to address deformities
Early Neurophysiological studies (at 6 weeks of age) may be a useful adjunct in decision making
No Shoulder activity/ No bicep activity by 3 months needs operative intervention
- Root avulsed
- Nerve transfer and tendon transfer are the only options
Nerve transfer include spinal accessory nerve, intercostal nerve and contralateral C7 nerve root
- Root Not avulsed
- Excise the scar and bridge the gap with a free sural nerve (graft)
The shoulder is prone to fixed IP and adduction deformity secondary to imbalanced motor activities. This results in progressive posterior dislocation of the shoulder.
Lack of bicep function 6 months after injury and the presence of Horner syndrome carry a poor prognosis
Miller’s Review of Orthopaedics 8th Edition
Physiotherapy is done to prevent this
If not treated by physiotherapy, treatment is done by
- Release of subscapularis (Commonly in its superior segment)
Supplemented by
- Tendon and muscle transfer for elbow flexion (Clark pectoral transfer and Steindler flexorplasty)
- Pectoral and subscapularis release for internal rotation contracture and secondary glenoid hypoplasia (<5 years old)
- Older children: Rotated osteotomy of the humerus
Steindler flexorplasty is the must commonly used muscle transfer
Fixed flexion deformity
- Splinting and serial casting
The child should be followed up, with an adolescent growth spurt until the shoulder approaches adult size.
See also: Brachial Plexus Injuries
See also: Thoracic Outlet Syndrome
