The Effect of Placing or not Placing Drainage after Primary Unilateral Total Knee Arthroplasty on Blood Loss and Knee Function: A Retrospective Study
Authors: Tan Shuyin , Zhao Dingyan , Yu Xing , Ma Yukun , Xiong Yang , Yue Xinliang , Zhou Yishu , Wei Jieyun , Meng Letian 
Published: July 2024

OBJECTIVE
To observe the impact of placing or not placing drainage on the changes in blood index and knee function recovery in patients undergoing initial unilateral total knee arthroplasty (TKA).
METHODS
A review was conducted on 115 cases of primary unilateral total knee arthroplasty (TKA) patients at our hospital. The patients were categorized into two groups: a drainage group (D group) and a non-drainage group (ND group) depending on the usage of a postoperative drainage tube. In Group D, there were 53 cases (10 males, 43 females) with an average age of 68.57 ± 5.34 years. The distribution of cases was 22 on the left knee and 31 on the right knee, with an average follow-up period of 15.57 ± 1.92 months. In Group ND, there were 62 cases (12 males, 50 females) with an average age of 67.15 ± 5.78 years. The distribution of cases was 26 on the left knee and 36 on the right knee, with an average follow-up period of 15.16 ± 2.04 months. Relevant data was collected for both groups of patients during hospitalization and follow-up periods, which included: pain assessment using the Visual Analogue Scale (VAS), evaluation of patient symptoms improvement using the Hospital for Special Surgery Knee Score (HSS), assessment of postoperative functional improvement based on knee swelling and knee range of motion, and evaluation of blood loss using hemoglobin (HGB), hematocrit (HCT), and total theoretical blood loss during surgery.
RESULTS
Both patient groups exhibited enhancements in postoperative VAS, HSS, and knee joint activity levels compared to pre-surgery values, all with statistically significant disparities (P < 0.05). There were no notable statistical variations in knee joint activity, VAS, and HSS at different follow-up intervals between the two patient groups before and after the surgical procedure (P > 0.05). Following surgery, knee swelling progressed incrementally over 3 days, culminating at its peak one week postoperatively, and subsequently subsided gradually. No significant statistical differences in knee swelling were observed between the two groups at any time point post-surgery (P < 0.05). Additionally, there were no statistically significant variances in preoperative levels of HGB (134.11 ± 12.16 vs. 135.66 ± 12.26) and HCT (39.76 ± 3.32 vs. 40.44 ± 3.60) between the patient groups (P > 0.05). One day following the surgery, both groups exhibited decreased HGB levels compared to the preoperative readings (D group: 112.91 ± 10.19 vs. 134.11 ± 12.16; ND group: 119.23 ± 11.56 vs. 135.66 ± 12.26, P < 0.05), and HCT levels demonstrated similar decreases compared to preoperative levels (D group: 33.24 ± 2.89 vs. 39.76 ± 3.32; ND group: 35.32 ± 3.61 vs. 40.44 ± 3.60, P < 0.05). The decrease in HGB and HCT levels in the D group was significantly greater compared to the ND group, with a statistically significant difference observed (HGB: 112.91 ± 10.19 vs 119.23 ± 11.56; HCT: 33.24 ± 2.8 vs 35.32 ± 3.61, P < 0.05). On the third day post-surgery, both HGB (D group: 100.06 ± 9.16 vs 112.91 ± 10.19; ND group: 108.98 ± 11.70 vs 119.23 ± 11.56) and HCT (D group: 29.45 ± 2.54 vs 33.24 ± 2.89; ND group: 32.28 ± 3.61 vs 35.32 ± 3.61) continued to decrease compared to the first-day post-surgery, with group D exhibiting lower levels of HGB and HCT than group ND (HGB: 100.06 ± 9.16 vs 108.98 ± 11.70; 29.45 ± 2.54 vs 32.28 ± 3.61, P < 0.05). Following seven days post-surgery, both groups demonstrated recovery in HGB (D group: 103.83 ± 9.58 vs 100.06 ± 9.16; ND group: 112.66 ± 12.17 vs 108.98 ± 11.70) and HCT (D group: 30.57 ± 2.68 vs 29.45 ± 2.54; ND group: 33.37 ± 3.75 vs 32.28 ± 3.61) compared to three days post-surgery. However, levels in group D remained lower than in group ND, with statistical significance. Throughout the perioperative period, the total blood loss in group ND was significantly less than that in group D (910.70 ± 242.73 vs 809.44 ± 228.55, P < 0.05).
CONCLUSION
Drainage may not be necessary after initial unilateral total knee arthroplasty (TKA). Omitting drainage can reduce the total amount of blood loss in patients and does not affect the postoperative recovery of knee joint function.