Farrell, J Bone Joint Surg Am 2005 - Motor Nerve Palsy Following Primary Total Hip Arthroplasty - Article Summary

Motor Nerve Palsy Following Primary Total Hip Arthroplasty

Farrell, Morrey, et al.·J Bone Joint Surg Am·2005·247 citations·Case-control study

Background

Nerve palsy is a potentially devastating complication following total hip arthroplasty. The purpose of this study was to retrospectively identify risk factors for, and the prognosis associated with, a motor nerve palsy following primary total hip arthroplasty.

Methods

Between 1970 and 2000, 27,004 primary total hip arthroplasties were performed at our institution.
47 patients (0.17%) with postoperative motor nerve dysfunction were identified by a review of the complications log of a total joint database.
The medical record of each patient provided the data for this study.
The average age of the patients was 57 years at the time of surgery.
The patients had serial clinical examinations for a minimum of 2 years, or until neurologic recovery or death.
The nerve palsies were classified as complete or incomplete, and only patients with objective motor weakness were included in the study.
The limb lengths were measured on preoperative and postoperative radiographs, and those data were then compared with the limb lengths in a matched cohort of patients who had not sustained a nerve injury after a primary total hip arthroplasty.
The extent of neurologic recovery, the need for braces or walking aids, and the use of medications for neurogenic pain were evaluated.

Results

There were 29 complete motor nerve palsies (16 peroneal, 11 sciatic, and 2 femoral) and 18 incomplete motor nerve palsies (14 peroneal, 3 sciatic, and one femoral).
A preoperative diagnosis of developmental dysplasia of the hip (p = 0.0004) or posttraumatic arthritis (p = 0.01), the use of a posterior approach (p = 0.032), lengthening of the extremity (p < 0.01), and cementless femoral fixation (p = 0.03) were associated with a significantly increased odds ratio for the development of a postoperative motor nerve palsy.
Of the 28 patients with a complete palsy who were available for follow-up, only 10 (36%) had complete recovery of motor strength, which took an average of 21.1 months.
7 of the 18 patients with an incomplete palsy fully recovered their preoperative strength.
21 patients required walking aids, and 15 required permanent use of an ankle-foot orthosis.
5 patients required daily medication for chronic neurogenic pain.

Conclusions

Motor nerve palsy is uncommon following primary total hip arthroplasty. A preoperative diagnosis of developmental dysplasia of the hip or posttraumatic arthritis, the use of a posterior approach, lengthening of the extremity, and use of an uncemented femoral implant increased the odds ratio of sustaining a motor nerve palsy. The majority of the motor nerve deficits in our series, whether complete or incomplete, did not fully resolve.

Supplemental

Motor Nerve Palsy Following Primary Total Hip Arthroplasty.

Farrell, Morrey, et al.J Bone Joint Surg Am2005247 citationsCase-control study