Clinical anatomy

Question 1

Janice is 70 years old and receives a total hip arthroplasty following a neck of femur fracture. Three months following the operation, she is assessed in orthopaedic outpatients and it is noted that she has a mild Trendelenburg gait.

What nerve do you suspect has been affected by the hip surgery?

Answer 1

The superior gluteal nerve

Question 2

How do the abductors (gluteus medius and gluteus minimus) aid normal walking?

Answer 2

• when a foot is lifted off the floor, the centre of gravity is transferred to the stance leg
• this is done by the contraction of the abductors to pull the pelvis over to the stance leg

Question 3

When is trendelenburg’s gait observed?

Answer 3

If the abductor muscles (G. medius and minimus) are not working on the stance leg

Question 4

Asides from surgery, what other common procedure could affect the superior gluteal nerve?

Answer 4

Intramuscular injections

Question 5

If the superior gluteal nerve is damaged on the left side, the patient will lose function to gluteus medius and minimus on their left. What will happen when a patient attempts to bear weight on their left lower limb?

Answer 5

The patient will fall to their right side, as nothing is pulling their centre of gravity over the stance leg

Question 6

Patient’s exhibiting trendelenburg’s sign will have to accommodate for this tilt during walking. What are the three gaits patients may may adopt in order to compensate for this?

Answer 6

1. waddling gait
2. swing gait
3. stepping gait

Question 7

A group of friends are playing volleyball on the beach. One of the teammates, Pete, dives for the ball with all his force and the group hear a gunshot. Pete is lying on the ground holding the back of his ankle in agony.

The FY1 that assesses Pete asks him to lay on front with his feet dangling off the bed. She squeezes each calf and notes that there is no reaction in the affected leg.

What test is being performed?
What is happening during the test?

Answer 7

1. Simmonds-thompson test
2. Squeezing the muscles causes them to contract, which should result in plantar flexion of the ankle

Question 8

What has happened to Pete?

Answer 8

He has ruptured his archilles tendon

Question 9

Will Pete’s injury affect any other movements performed by the injured muscle?

Answer 9

no

although the gastrocnemius also flexes the knee joint, the hamstrings are the main knee flexors so knee flexion carries on as normal

Question 10

Why will wearing a moon boot aid Pete’s healing?

Answer 10

The boot puts the affected muscles in a position of non-function.

This avoids stretching the muscle which will allow the rupture to heal