Diabetes mellitus may be a risk factor for sciatic nerve injury during total hip arthroplasty

Sciatic nerve palsy during hip arthroplasty can negatively affect the outcome of total hip arthroplasty (THA). Although no causes could be found in majority of cases some risk factors including leg lengthening, direct injury, damage of vascular supply have been reported. We aimed to investigate if diabetes mellitus (DM) increases the incidence of sciatic nerve palsy during THA. In a retrospective review on 1528 primary total hip arthroplasty (1219 patients) 16 cases of post-operative sciatic nerve palsy were identified. They were matched to a group of 96 patients of the same sex and gender but with no sciatic nerve injury. The prevalence of DM and the amount of leg lengthening were compared between the two groups. The ratio of male to female was the same in both groups (69% female, 31% male). The mean age at the time of surgery was 47.3 years (range 33-62) and 49.2 years (range 32-64) for the groups with and without nerve palsy, respectively. The amount of limb lengthening resulted from surgery was not significantly different between the groups (18.5mm in for the study group with nerve palsy versus 17.6mm for the control groups, p = 0.79) Seven patients in the study group (44%) and 20 patients in the control group (21%) were found to have diabetes. The difference had a trend to be significant (p = 0.06). Although the number of diabetic cases in both groups showed no significant difference, but larger ratio of patient with sciatic nerve palsy had diabetes (44% versus 21%). Further studies with larger population are needed to evaluate the role of diabetic mellitus on the sciatic nerve palsy after hip arthroplasty.