Orthopaedics

Question 1

Superior gluteal L4-S1 injury

Answer 1

IM injection in superomedial region

Hip abduction

Trendelenburg +ve

Question 2

Inferior gluteal (L5-S2)injury

Answer 2

Trauma, psoas haematoma, aortic or iliac aneurysm, pelvic, abdominal or spinal surgery, femoral line

Motor – hip flexion, knee extension, patellar reflex

Sensory – anteromedial thigh (anterior cutaneous branches), medial lower leg and foot (saphenous nerve)

Question 3

Lateral cutaneous (L2-4) injury

Answer 3

Compression at inguinal ligament e.g. increased intra-abdominal pressure, tight belt or pants, local tumour or haematoma

Sensory – pain and paraesthesia of lateral surface of thigh

Question 4

Obturator (L2-4) injury

Answer 4

Pelvic ring fracture, obturator hernia

Sensory – medial thigh

Motor – hip ADduction

Question 5

Sciatic (L4-S3) injury

Answer 5

Intragluteal injection, trauma, hip dislocation, THR

Sensory – lower leg and foot

Motor – plantar flexion of foot, inversion and toe flexion (tibial nerve), foot dorsiflexion, toe extension and eversion (peroneal nerve)

Question 6

Tibial (L4-S3) injury

Answer 6

Tibial fracture, tarsal tunnel syndrome

Sensory – sole of foot

Motor - plantar flexion of foot, inversion and toe flexion I.e. cant walk on toes

Question 7

Common peroneal (L4-S2)

Answer 7

Fracture of fibular head, compression e.g. cast, sitting cross-legged, lithotomy position

Sensory deficit -

Deep peroneal nerve: area between the first and second toes (flip-flop zone)

Superficial peroneal nerve: back of the feet and toes, lateral surface of the lower leg

Motor deficit

Deep peroneal nerve: paralysis of foot and toe extensors (dorsiflexors) → foot drop → high-stepping gait

Superficial peroneal nerve: paralysis of peroneus longus and peroneus brevis → impaired pronation of the foot

Question 8

Sural (L4-S3)

Answer 8

Achilles tendon rupture, ganglion, lipoma

Sensory – posterolateral lower leg, lateral border of foot, under heel

Question 9

Phases of fracture healing

Answer 9

Reactive phase (injury – 48hrs)

• Bleeding into site forms haematoma
• Inflammation leads to granulation tissue

Reparative phase (2 days – 2 weeks)

• Proliferation of osteoblasts and fibroblasts leads to callus formation
• Consolidation (endochondral ossification) of woven bone to lamellar bone

Remodelling phase (1 week- 7 years)  
 - Remodelling of lamellar bone to cope with mechanical forces applied to it (Wolff’s Law: form follows function)