14.1 Musculoskeletal Anomalies & Neonatal Birth Injuries
Key Takeaways
- Ortolani reduces a dislocated hip with a palpable clunk in during abduction, while Barlow dislocates a located hip with a clunk out during adduction and posterior pressure; examine one hip at a time on a quiet infant, then confirm with ultrasound at around 6 weeks, because the newborn femoral head is cartilaginous and invisible on plain radiographs until roughly 4 to 6 months of age.
- Metatarsus adductus involves only the forefoot with a normal ankle that dorsiflexes past neutral, whereas talipes equinovarus is a rigid four-part deformity (equinus, varus, forefoot adduction, cavus) requiring Ponseti serial casting.
- The single best discriminator between brachial plexus injuries is whether the hand grips: an intact grasp with a waiter's tip posture indicates Erb-Duchenne palsy at C5-C6, while an absent grasp with claw hand indicates Klumpke palsy at C8-T1, possibly with Horner syndrome.
- An infant with an upper brachial plexus injury who also has respiratory distress and asymmetric or paradoxical chest movement may have phrenic nerve injury with a paralyzed hemidiaphragm, which is an escalation emergency rather than an orthopedic finding.
- Traumatic facial nerve palsy paralyzes the whole side of the face including eye closure and requires corneal lubrication, whereas isolated lower-lip asymmetry from absent depressor anguli oris spares eye closure and warrants an echocardiogram for associated cardiac anomalies.
14.1 Musculoskeletal Anomalies & Neonatal Birth Injuries
Clinical Pearl & Core Takeaway: Musculoskeletal and Integumentary is one of the seven named sub-domains under Assessment and Management of Pathophysiologic Conditions, and Neuromuscular birth injuries sit under Neurological. Almost every finding in this section is discovered by a nurse doing a routine newborn examination, not by imaging. An asymmetric Moro, a hip that clunks, a shoulder that will not move — these are nursing findings, and missing them delays treatment during the narrow window when treatment is easiest.
1. Developmental Dysplasia of the Hip (DDH)
DDH is a spectrum from a shallow acetabulum through subluxation to frank dislocation. It is the musculoskeletal condition most often missed in the newborn nursery, and the cost of missing it is a childhood of surgery instead of a few months in a harness.
Risk factors — the "4 F's plus one"
Female (six times the male incidence), Firstborn, Frank breech presentation (the single strongest risk factor), Family history, plus oligohydramnios — all of which share a common mechanism of restricted intrauterine movement and sustained hip flexion with extension of the knees.
Physical examination maneuvers
| Maneuver | Technique | Positive Finding | What It Means |
|---|---|---|---|
| Ortolani | Hip flexed to 90°, gently abduct while lifting the greater trochanter anteriorly | A palpable "clunk in" as the femoral head relocates into the acetabulum | The hip was dislocated and has been reduced |
| Barlow | Hip flexed and adducted, apply gentle posterior pressure | A palpable "clunk out" as the femoral head dislocates posteriorly | The hip is located but dislocatable |
Remember the direction: Ortolani puts it in (O = in), Barlow pushes it out (B = back/out).
Supporting signs
- Asymmetric thigh and gluteal skin folds.
- Galeazzi (Allis) sign: with hips and knees flexed and feet flat on the bed, the knee on the affected side sits lower, because the femur is displaced posteriorly.
- Limited abduction on the affected side — this becomes the dominant sign after 8–12 weeks, once soft-tissue contracture develops and the clunks disappear.
Critical technique point: examine one hip at a time, on a relaxed, quiet infant, using gentle pressure. A crying, tensed infant guards the hip and produces a falsely normal examination. Forceful maneuvering can itself injure the femoral head.
Diagnosis and management
- Ultrasound is the imaging study of choice, usually at around 6 weeks of age — before the femoral head ossifies. Plain radiographs are useless in the newborn because the femoral head is cartilaginous; they become useful only after about 4 to 6 months.
- Treatment is the Pavlik harness, which holds the hips in flexion and abduction so the femoral head models a proper acetabulum. Parent teaching centres on not adjusting the straps, skin checks under the straps, and diapering without removing the harness.
- Never counsel parents to swaddle with the legs extended and adducted. Swaddling must leave the hips free to flex and abduct — tight lower-body swaddling is an established, preventable cause of DDH.
2. Foot and Digit Anomalies
| Condition | Findings | Distinguishing Feature | Management |
|---|---|---|---|
| Metatarsus adductus | The forefoot is adducted (curves medially); the hindfoot and ankle are normal, and the foot dorsiflexes past neutral | The lateral border of the foot is convex, but the ankle moves normally — this is the key discriminator from clubfoot | Flexible (correctable past midline with gentle pressure) resolves spontaneously in the great majority; rigid forms need serial casting |
| Talipes equinovarus (clubfoot) | Four fixed deformities: equinus (plantar flexion), varus (heel inversion), forefoot adduction, and cavus (high arch) | The deformity is rigid and cannot be passively corrected to neutral; the calf is often thinner and the foot smaller | Ponseti method — weekly serial casting begun in the first weeks of life, percutaneous Achilles tenotomy in roughly 80%, then a foot-abduction brace for years. Non-adherence to bracing is the main cause of relapse |
| Polydactyly | Extra digit(s). Postaxial (little-finger side) is far more common than preaxial | Postaxial type B — a narrow, pedunculated skin tag with no bone — is common and frequently familial | Type B may be ligated or excised; digits containing bone or a joint require surgical planning. Preaxial (thumb-side) polydactyly is more often syndromic and warrants evaluation |
| Syndactyly | Webbing or fusion of adjacent digits, most often the third and fourth fingers or second and third toes | May be simple (skin only) or complex (bony fusion) | Elective surgical separation; toe syndactyly frequently needs no treatment. Look for associated syndromes |
3. Congenital Muscular Torticollis
Shortening or fibrosis of one sternocleidomastoid (SCM) muscle, often from intrauterine positioning or a birth-related hematoma within the muscle.
- Classic posture: the head tilts toward the affected side and the chin rotates away from it — the SCM both tilts the head ipsilaterally and rotates the face contralaterally, so a shortened muscle does both.
- A firm, non-tender "olive" mass may be palpable in the belly of the muscle in the first weeks.
- Associated conditions you must screen for: plagiocephaly (the infant always rests on the same side of the skull) and developmental dysplasia of the hip — both arise from the same restricted intrauterine environment.
- Management: early, frequent passive stretching taught to parents, prone tummy time while awake and supervised, and positioning the crib, toys, and caregiver approach so the infant must turn toward the restricted side. Physical therapy referral. Untreated torticollis produces permanent facial asymmetry.
4. Fractures of Birth
Clavicular fracture — the most common birth fracture
- Risk factors: shoulder dystocia, macrosomia, instrumented delivery, breech extraction.
- Findings: crepitus or a palpable irregularity over the clavicle, asymmetric Moro reflex (the arm on the affected side does not abduct), pseudoparalysis of the arm, and crying with passive movement of the shoulder. Some fractures are entirely silent and are discovered only when a firm callus appears at 7 to 10 days.
- Management: no reduction and no cast. Handle gently, support the arm, avoid lifting from under the axillae, and dress the affected arm first and undress it last. Some units pin the sleeve to the shirt for comfort. Healing is complete in 2 to 3 weeks with excellent remodeling.
- Rule out an associated brachial plexus injury — the two travel together, and both cause a limp arm with an asymmetric Moro.
Humeral and femoral fractures are far less common and are usually associated with breech extraction or with underlying osteogenesis imperfecta, which should be considered when a fracture occurs after an atraumatic delivery.
5. Brachial Plexus Injuries
Traction on the plexus during delivery of the shoulders. The level of injury determines the posture, and the posture is the whole answer on an examination item.
| Injury | Roots | Classic Posture | Grasp Reflex | Additional Findings |
|---|---|---|---|---|
| Erb-Duchenne palsy (by far the most common) | C5–C6 | "Waiter's tip" — shoulder adducted and internally rotated, elbow extended, forearm pronated, wrist flexed | INTACT — the hand works | Absent Moro on the affected side; may co-exist with a clavicular fracture |
| Klumpke palsy (rare in isolation) | C8–T1 | "Claw hand" — wrist and fingers cannot flex or extend properly, intrinsic hand muscles paralyzed | ABSENT — the hand does not grip | May show Horner syndrome (ipsilateral ptosis, miosis, anhidrosis) from T1 sympathetic involvement |
| Total plexus palsy | C5–T1 | Entire limb flaccid | Absent | Worst prognosis |
The single most useful discriminator: does the hand grip? Grip intact = Erb (upper roots). Grip absent = Klumpke (lower roots).
Phrenic nerve involvement (C3, C4, C5) is the emergency. The phrenic nerve arises from the same upper roots as Erb palsy, so an infant with an upper plexus injury who also develops respiratory distress, tachypnea, and asymmetric or paradoxical chest movement may have a paralyzed hemidiaphragm. Suspect it, position the infant with the affected side down, and escalate for ultrasound or fluoroscopy of diaphragmatic motion.
Nursing management: gentle handling with the affected arm supported across the abdomen, no passive range of motion for the first 7 to 10 days while inflammation settles, then a physical therapy program of gentle range-of-motion exercises taught to the parents. Most stretch injuries recover substantially within 3 to 6 months; failure to recover biceps function by 3 months prompts surgical referral.
6. Facial Nerve (CN VII) Palsy
Compression of the facial nerve where it exits the stylomastoid foramen — classically from forceps, but equally from prolonged pressure of the fetal face against the maternal sacral promontory during labor.
- Findings: the affected side does not move. At rest the face may look nearly normal; the abnormality declares itself with crying, when the unaffected side moves and the mouth pulls toward the normal side. The eye on the affected side stays open and the nasolabial fold is flattened.
- Critical differential — asymmetric crying facies: congenital absence or hypoplasia of the depressor anguli oris muscle produces asymmetry of the lower lip only. Eye closure, forehead movement, and the nasolabial fold are normal. This distinction matters because absent depressor anguli oris is associated with cardiac and other anomalies (including 22q11.2 deletion) and warrants an echocardiogram, whereas an isolated traumatic facial palsy needs only supportive care.
- Nursing priority — protect the cornea. An eye that cannot close will dry and ulcerate. Instill artificial tears or lubricating ophthalmic ointment as ordered, and patch the eye at night if directed.
- Feeding support: an incomplete lip seal makes latching difficult. Support the cheek and chin, and involve lactation early.
- Prognosis: the great majority of traumatic facial palsies resolve spontaneously within days to a few weeks.
A 4,300 gram infant delivered vaginally after a shoulder dystocia holds the right arm adducted and internally rotated with the elbow extended, the forearm pronated, and the wrist flexed. The Moro reflex is absent on the right, but the right palmar grasp is strong and symmetric with the left. Which injury does this presentation identify?
A term female infant delivered in frank breech presentation has asymmetric thigh folds, and the nurse elicits a palpable clunk as the left femoral head slips back into the acetabulum during abduction. Which maneuver produced this finding, and what is the appropriate next diagnostic step?
A term infant delivered by forceps shows a face that appears symmetric at rest. When the infant cries, the left side of the face does not move, the left eye remains open, and the mouth pulls toward the right. Which nursing intervention takes priority?