Anterior skin numbness after total knee arthroplasty: A prospective comparison study between diabetic and non-diabetic patients.

Abstract

Anterior skin numbness from injury of the infrapatellar branch of saphenous nerve (IPBSN) and/or the anterior-inferior branch of the femoral cutaneous nerve (AIBFN) has been reported after TKA. A recent study has demonstrated no difference in skin numbness between minimally invasive and standard approach TKA. The purpose of our study was to compare the area of skin numbness following TKA in the diabetic and non-diabetic patient. 120 patients (41 type II diabetic and 74 non-diabetic) undergoing TKA were evaluated. Five diabetic patients with preoperative skin numbness were excluded. Area of anterior skin numbness was periodically evaluated with a minimum 2-year follow-up (FU). Clinically, there was no difference in prevalence of skin numbness (73.2% vs 68.9%, p = 0.36) and warmness (97.6% vs 97.3%, p = 1.00) between diabetics and non-diabetics. Average area of numbness was comparable. However, duration of numbness recovery was significantly longer in diabetics (8.6 vs 5.3 months, p = 0.001). Diabetics had a higher rate of global anterior numbness (48.3% vs 22.9%, p = 0.045). Prevalence of supero-lateral skin numbness (2.6%, n = 3) correlated with the skin incision extended proximally above upper pole of patella at least 4.0 cm. The duration of numbness recovery following TKA was significantly longer in diabetic patients.