Orthopaedics: Spine

Question 1

What are the most common nerve roots affected by sciatica?

Answer 1

L4, L5 and S1

Question 2

What disc has prolapsed if you have pain down the medial ankle, loss of quadriceps power and reduced knee jerk?

Answer 2

L3/L4 prolapse which leads to L4 root entrapment

Question 3

What disc has prolapsed if you have pain on the dorsum of the foot, reduced power of the extensor hallucis longus and tibialis anterior?

Answer 3

L4/L5 prolapse resulting in L5 root entrapment

Question 4

What disc has prolapsed if you have pain in the sole of the foot, reduced power and reduced ankle jerks?

Answer 4

L4/S1 prolapse resulting in S1 nerve root entrapment

Question 5

What are indications for spinal disc surgery?

Answer 5

Pain not resolving depsite physiotherapy and there are localising signs suggesting a specific nerve root involvement

Question 6

What is spinal stenosis?

Answer 6

Spondylosis, bulging discs, bulging ligamentum flavum and osteophytes means that the cauda equina of the lumbar spine has less space - this leads to multiple nerve roots being compressed and irritated.

Question 7

What investigation do you do if you suspect cauda equina?

Answer 7

MRI