Nerve Injury in Patients after Hip and Knee Arthroplasties and Knee Arthroscopy

Abstract

To examine the reporting of lower limb neuropathy within 90 days of surgery for patients undergoing hip arthroplasty, knee arthroplasty, or knee arthroscopy. This was a retrospective study using data from the 1998 MarketScan Commercial Claims and Encounter Database (The MEDSTAT Group) to identify lower limb neuropathy after these surgeries. The sample was selected within the first 9 months of 1998 using International Classification of Diseases, 9th Revision (ICD-9), and Current Procedural Terminology (CPT) codes for hip and knee surgical procedures. Lower limb nerve injuries as determined by ICD-9 codes within 90 days postsurgery were the main outcome measures. The influence of diabetes on the rates of nerve injuries after surgery was also examined. A total of 14,979 patients underwent these surgical procedures, 10 of whom were reported to have sustained a nerve injury postsurgery (0.07%). The sample comprised mainly men (53.1%), and the largest groups consisted of those aged 45-54 yrs (27.0%) and 55-64 yrs (27.7%). Nerve injury occurred at a rate of 0.03% after hip arthroplasty, 0.01% after knee arthroplasty, and 0.02% within 3 mos of arthroscopic knee surgery. Overall, nerve injuries were two times more prevalent in the diabetic vs. nondiabetic population (0.11% vs. 0.06%); however, this difference did not meet conventional levels of statistical significance. Specific to knee arthroplasty, there were 10-fold differences in nerve injury rates between diabetic and nondiabetic patients, 0.11% vs. 0.01%, respectively (P <or= 0.01), although the overall risks were small. Nerve injuries after hip and knee arthroplasty and knee arthroscopy were rare in a large population of patients younger than 65 yrs. Although the overall rates were low, there was an increased occurrence of nerve injuries in the diabetic population. This information is useful when counseling patients and benchmarking surgical complication rates.