A research of the relationship between the using of tourniquet in the total knee artroplasty and the hoffa's fat pad's ischemia/reperfusion damage

Objective: To determine the ischemia reperfusion injury in the hoffa's fat pad after the usage of tourniquet in total knee arthroplasty surgery and to detect the requirement of the hoffa's fat pat excision. Material and Method: 80 knees (44 female and 14 male) of patinets who underwent total knee arthroplasty were evaluated in this study. Patients demographics were recorded. Knee Society Score (KSS), Knee injuriy and Osteoarthitis Outcome Score (KOOS) and Kujala pain score questionnaire were assesed preoperative and at 3rd postoperative month. Knee examinations were compared preoperative and postoperative. Tourniquet were used in 40 total knee arthroplasty surgeries and wasn't applied in the other 40 knees. İn the tourniquet group, 2 samples from hoffa's fat pad were taken after 5 minutes from tourniquet application (t1), 1 minute before ending the tourniquet (t2) and 15 minutes after ending the usage of tourniquet (t3)(1 minute before the colsure of fascia). İn the non-tourniquet group, 2 samples from hoffa's fat pad taken 5 minutes after the start of incision (t1) and 1 minute before the colsure of fascia (t3). HIF 1α, BAX/Bcl-2, Total Oxidant Capacity (TOC), Total Antioxidant Capacity (TAC) ve Oxidative Stress İndex (OSI) values were assesed from these tissues. İschemia and reperfusion injury compared between the groups. Result: No differance in patients demographics found between the groups. No significant differanse found between patients' preoperative and postoperative knee flexions (p=0,625). Postoperatif knee extension and range of motion were significantly increased. Postoperatif KSS, KOOS and Kujala scores were significantly increased. No significant differanse found between the groups in KSS, KOOS, Kujala score, ROM and knee flexion and extensions. İn the tourniquet applied group, HIF 1α value was low, BAX/Bcl-2 ratio was high, TAC value was similar, TOC value was high and OSI value was high in t1. HIF 1α value was similar, BAX/Bcl-2 ratio was low, TAC value was similar, TOC value was high and OSI value was high in t3. İn the hoffa's fat pad taken from the tourniquet group, oxidative stress was tow time higher than the other group. İn the Tourniquet group, preoperatif oxidative stress was high in hoffa's fat pad tissue in t1 and decreased by time, then slightly increased again after endig tourniquet. Conclusion: İn this study, the ischemia reperfusion injury in the hoffa's fat pad was high biochemically and histologically in the tourniquet group. Because the ischemia reperfusion injury in the hoffa's fat pad was high in total knee arthroplasty patients with tourniquet usage, it is up to the surgion weather to remove the hoffa's fat pad. Performing TKA without use of tourniquet can decrease complications. We think that assessing the clinic effect of the usage of tourniquet and the removal of hoffa's fat pad tissue better requires a longer clinic follow up and further studies.