Effect of tourniquet use on total blood loss following total knee arthroplasty

INTRODUCTION

Total knee arthroplasty (TKA) is commonly performed to treat patients with knee arthritis. Blood loss during TKA can be a concern. Therefore, a tourniquet is used to minimize the risk of bleeding and any associated complications. Arthroplasty surgeons have different views regarding tourniquet use in TKA. Although an increasing number of surgeons do not use it, it remains common practice to use tourniquets for TKA, despite the risk of local and systemic adverse effects. These adverse effects include thigh pain, nerve damage, reactive hyperemia with tourniquet release, altered hemodynamics with limb exsanguination, and delay in neuromuscular recovery.^[1,2] Furthermore, there is a potentially higher risk for significant venous emboli dissemination and vascular injury in atherosclerotic arteries and an increase in wound healing disturbances.^[3] Moreover, muscle atrophy could occur after TKA; one study reported that atrophy occurred at a rate of 1% per day for the first 2 weeks as a result of tourniquet-induced ischemic reperfusion injury.^[4] The proposed advantages of not using a tourniquet in TKA could be lesser post-operative pain, better range of motion, lesser limb swelling, greater strength, and faster recovery.^[4-6]

Arthroplasty surgeons use tourniquets mainly to reduce visible and hidden blood loss during TKA, resulting in significant anemia and prolonged post-operative recovery.^[7] Moreover, operating in a bloodless field may reduce the operating time, enhance visualization, and improve cement bone fixation. The percentage of hidden blood loss in primary TKA ranges from 30% to 56% of the calculated total blood loss.^[8-10] However, multiple studies comparing decreases in post-operative hemoglobin between the tourniquet and non-tourniquet groups showed no significant difference.^[11-16] A similar finding was also observed in obese patients, where tourniquet use was not associated with reduced blood loss or increased postoperative complications following TKA.^[17] Nevertheless, many reports had demonstrated reduced intraoperative blood loss and total blood loss when tourniquets were used,^[18-21] whereas others found increased total blood loss resulting from hemolysis if a tourniquet was used.^[22]

This difference in the reported studies could be attributed to many factors, including pre-operative hemoglobin levels, surgical techniques, patient’s gender, patient’s age, or ethnic group. The main purpose of this study was to assess the total blood loss and need for transfusion following primary unilateral TKA with and without a tourniquet.

MATERIALS AND METHODS

A cross-sectional study design was conducted to retrospectively review all patients who underwent primary TKA for primary knee osteoarthritis in two institutions from November 2017 to March 2020. Approval was obtained from the institutional ethical boards of the two participating institutions. The study included 276 patients who met the inclusion criteria, who were then categorized into two groups: 159 patients in the tourniquet (TQ) group and 117 patients in the non-TQ (N-TQ) group. Exclusion criteria were specified as simultaneous bilateral TKA; post-traumatic arthritis; previous high tibial osteotomy; rheumatoid arthritis; hemoglobin <10 g/dL; history of venous thromboembolism (VTE); and body mass index (BMI) >40. In addition, the data collected included the patient’s age, gender, pre- and postoperative hemoglobin levels, surgical time, post-operative VTE rate, and transfusion data.

RESULTS

Two hundred and seventy-six patients were enrolled in this study. The mean age of the study population was 62.8 ± 7.2 years, and 76.4% of patients were females. Demographic data showed that the N-TQ group consisted of 117 patients, 77.8% of whom were females. The mean age of the N-TQ group was 63.3 ± 6.6 years, and 74.4% of them were aged ≥60 years. By contrast, the TQ group consisted of 159 patients, and 75.5% of them were females. The mean age of the TQ group was 62.5 (±7.6) years, and 61.0% were aged ≥60 years [Table 1]. The two groups were homogenous, and there was no significant difference in the age distribution (P = 0.342) or gender distribution (P = 0.655) between the groups [Table 1]. In addition, there were no significant differences in the pre-operative hemoglobin levels between the groups [Table 2].

The mean decrease in hemoglobin levels in the N-TQ group was 1.16 g/dL (±0.93) compared to 1.44 g/dL (±0.80) in the TQ group, with no statistically significant differences in post-operative hemoglobin levels between both groups (P = 0.907), [Table 2]. Moreover, three patients received blood transfusion in each group, and there was no statistically significant difference in blood transfusion need between the two groups [Table 3].

To study the impact of age on hemoglobin drop postoperatively, we compared post-operative hemoglobin drop in patients aged ≥60 years to patients aged <60 years and found no statistically significant differences in both groups [Table 4]. However, we found that the female gender was a predictor factor for post-operative hemoglobin reduction compared to the male [Table 5].

DISCUSSION

TKA is an operation successfully used to relieve pain and improve mobility in patients with end-stage osteoarthritis. However, the outcome is influenced by many factors.^[23-25] We found that using a TQ in primary TKA did not affect total blood loss postoperatively. Orthopedic surgeons are accustomed to using TQ in TKA to minimize intraoperative blood loss despite the contradictory results in the literature. Although TQ use has many proposed advantages, such as operating in a bloodless field and better cement bone fixation, many drawbacks of using it may impact the outcome.^[26,27] The ischemic condition caused using a TQ may lead to sustained local reactive hyperemia for several hours following TQ release. This hyperemic response could lead to more bleeding into the traumatized tissue postoperatively.^[28,29] In addition, the increased fibrinolytic activity associated with TQ-induced ischemia may promote local post-surgical bleeding.^[22,28,30] Nevertheless, some authors suggested that it could be controlled after the application of wound pressure dressing.^[31,32] Li et al. found that the extent of hemo-cytolysis was more serious with a TQ and concluded that using a TQ in TKA may promote post-operative hidden blood loss and delay rehabilitation exercises.^[8] Some studies proposed using limb occlusion pressure (LOP) instead of the conventional method to estimate occlusion pressure to minimize the postoperative complication of TQ uses.^[33,34] However, they found that LOP methodology helps in reducing thigh pain and swelling without impact on the surgical field visualization or amount of blood loss.

Studies found that the need for transfusion could be reduced when using TQs.^[35,36] However, our results showed that there was no significant difference in the need for blood transfusion postoperatively with or without TQ use, consistent with the findings of other studies.^[18,19,37] The need for blood transfusion in our study was minimal compared to findings of other published reports.^[38,39] This finding could be related to pre-operative optimization of patient conditions, such as hemoglobin levels, use of tranexamic acid, and our high threshold for transfusing patients based on postoperative clinical and laboratory findings. Some authors found that low pre-operative hemoglobin, long operative time, BMI more than 30, and general anesthesia were major predictors of blood transfusion needs after TKA.^[40-42] TQ use was reported to be associated with a higher risk of developing VTE complications following TKA.^[43] However, our results showed no difference in the incidence of thromboembolism complications with or without TQ use. This finding was consistent with those of other studies showing no difference in VTE events between the groups.^[19,44] In our opinion, orthopedic surgeons need to consider balancing the risks and benefits of using a TQ during TKA. Our study results support previous findings, which showed that TQ s use have no effect on minimizing total blood loss following TKA. Zhang et al. conducted a systematic review and showed no significant differences between the two groups in terms of actual blood loss.^[45] Tarwala et al. suggested that no significant clinical differences existed between patients who had a TQ inflated throughout the procedure compared with those who had it inflated only during cementation.^[46] However, the only benefit of TQ inflation during cementation is to help the surgeon working in a bloodless field for better bone fixation and reduce the risks associated with the prolonged TQ application.^[26,46] Although the use of TQs has many advantages, not using TQs also has many advantages, including lesser use of pain killers, better early range of motion, and earlier straight leg raising.^[5,47] However, these minor complications did not impact post-operative recovery in either group.^[5,48]

The timing of TQ release is an important issue that needs to be considered. Although releasing a TQ before wound closure may increase total blood loss and operative time, meticulous hemostasis can lower the risk of complications.^[49] Therefore, releasing TQ s before wound closure to reduce the risk of complications would not be an appropriate decision. A similar conclusion drawn from a meta-analysis demonstrated that the total blood loss when the TQ was deflated before wound closure was significantly higher than when the TQ was deflated after wound closure.^[50]

Regarding the gender prediction of increased blood loss following TKA, our results showed that the female gender is a predictor of higher total blood loss, with or without the use of a TQ. However, this was not reflected in the need for blood transfusion in females. This finding was contradictory to other studies, where the male gender was found to be a predictor of increased total blood loss following TKA.^[9,47,48] However, some studies found no differences in total blood loss between males and females.^[38] This finding might be attributed to the different ethnicities of the patients in these studies.

We acknowledged that our study had some limitations to be considered. The presented work retrospectively analyzed the effect of TQ use in TKA and its impact on total blood loss postoperatively. Due to this retrospective collection of data, we could not identify specific criteria defining the basis of using a TQ or not. However, we believe that the finding of this study can be used as supporting evidence that would encourage arthroplasty surgeons to reconsider this practice. In addition, we could not study other factors, such as pain score, muscle strength, need for narcotics, or other functional scores because of the lack of uniformity in recording such factors between the centers.

CONCLUSION

Using a TQ during TKA does not affect post-operative hemoglobin levels, the need for blood transfusion, or the incidence of deep vein thrombosis and pulmonary embolism following TKA. Female gender was found to be a predictor of increased blood loss following TKA with and without TQ use. Therefore, arthroplasty surgeons must weigh the risks and benefits of using a TQ during TKA.