A comparative study of the hemodynamic and clinical effects of using or not tourniquet in total knee arthroplasty.

Background: Pneumatic tourniquet is widely used in lower limb surgery to provide a bloodless operating field. Previous studies on total knee arthroplasty (TKA) in which tourniquets have been applied during surgery have reported some vascular and soft-tissue complications. Nevertheless, it is still not well known exactly how use of tourniquets contributes to hemodynamics of the lower limb and its clinical relevance following TKA. In this prospective study, we wished to determine whether tourniquet affects the hemodynamics and postoperative healing of the lower limb in the first few weeks and its clinical relevancies following TKA.

Methods: We prospectively collected consecutive 110 patients with advanced osteoarthritis of the knee. All the subjects were randomly assigned to one of two TKA procedures: TKA with (Group T) or without (Group O) tourniquets. The hemodynamics of each operated leg was assessed by Doppler, first before the operation, then postoperatively on days 2, 6, 14, and 28. The operative and postoperative managements were done the same as those described in the papers done by the author. Parameters during the operative and postoperative course, including, demography, pre- or postoperative knee score, tourniquet time, operation time, estimated blood loss, perioperative blood transfusion, hospital course, and complications will all be recorded and compared in detail. All patients were measured for all response variables, which included demographic variables, results of Doppler, and important surgical outcomes. Fisher's exact test was used to compare differences between the two groups for each discrete variable, and a Mann-Whitney Rank Sum Test was used to analyze each continuous variable. The p value was set for each test at 0.05 before analysis took place. In accordance with the repeated measures, the venous hemodynamic parameters were checked. If any significant differences appeared in the overall test, values were then compared in pairs using two sample t-tests for all statistical tests. The level of significance was set at p < 0.05.

Results: In our 110 patients (55 with tourniquet, 55 without), all checked clinical parameter were without significant difference except postoperative quadriceps muscle recovery. This implied tourniquet use influenced postoperative rehabilitation program. Blood loss amount were similar in both groups. There was only one DVT found.

Conclusion: Tourniquet use in TKA must be managed very carefully. Not only because of immediate complication resulted from tourniquet but also influence on post-operational functional recovery, especially in quadriceps muscle function. According to this study, TKA without tourniquet use preserves better quadriceps muscle function to provide faster recovery and less transfusion need. It avoids complications from tourniquets as well.