Differential knee skin temperature following total knee arthroplasty and its relationship with serum indices and outcome: A prospective study

OBJECTIVES: To monitor knee skin temperature changes for 12 months following total knee arthroplasty (TKA) and identify potential reasons for any differences in skin temperature and to investigate if there is a relationship between the differential temperature and clinical outcome. METHODS: Patients who attended for a unilateral TKA due to primary osteoarthritis between August 2012 and August 2014 were eligible for this prospective study. The skin temperature of both knees was monitored preoperatively and postoperatively using an infrared thermometer. Serum indices and Hospital for Special Surgery (HSS) knee scores were assessed. RESULTS: Thirty-nine patients were involved in the study. The skin temperature of both knees as well as the differential temperature increased following TKA. Serum haemoglobin, haematocrit and days from surgery showed inverse correlations with the differential temperature, while body mass index and American Society of Anesthesiologists scores showed positive correlations. There was a strong inverse correlation between the differential temperature and HSS. score. CONCLUSIONS: Differential knee skin temperature elevation 12 months post-TKA may be a normal surgical response.