|
Year |
2007 |
|---|---|
|
Question Number |
110 |
|
Category |
Hip and Knee Reconstruction |
Question
Which of the following clinical factors is associated with an increased risk of developing sciatic nerve palsy after total hip arthroplasty?
1- Obesity
2- Hip dysplasia
3- Rheumatoid arthritis
4- Prior history of Perthes disease
5- Prior history of slipped capital femoral epiphysis
Figures
Answer (click for answer)
The correct answer is 2- Hip dysplasia
Hip dysplasia is associated with an increased risk of sciatic nerve palsy after total hip arthroplasty. The overall prevalence of neurologic injury following THA is around 1%. 80% of the time the sciatic nerve or the peroneal branch of the sciatic nerve is involved. Other risk factors for neurologic injury include female sex, posttraumatic arthritis and revision surgery. The origin of the palsy is unknown and unrecognized compression may play a role. The prognosis is related to the degree of damage. Complete or essentially complete recovery occurs in approximately 41% and another 44% have a mild deficit. 15% have a poor outcome characterized by weakness that limits ambulation and or persistent dysesthesia. Those patients with some motor function immediately post-op and those w/ returned function w/in 2 weeks have a good prognosis. Femoral nerve palsy is more predictable than sciatic nerve palsy.
Another study retrospectively reviewed 27,004 primary THAs between 1970 and 2000 and found a 0.17% incidence of nerve palsy. Pre-operative diagnoses of developmental dysplasia or post-traumatic arthritis, use of the posterior approach, lengthening of the limb and cementless femoral fixation were associated with an increased odds ratio for development of a post-operative motor nerve palsy. The majority of nerve deficits did not resolve completely.
Reference: Farrell CM, Springer BD, Haidukewych GJ, Morrey BF: Motor nerve palsy following primary total hip arthroplasty. J Bone Joint Surg Am 2005; 87: 2619-25