Abstract
Objective
This study was conducted to investigate the effectiveness of using drainage tubes after high tibial osteotomy.
Methods
Clinical data of 164 patients who underwent high tibial osteotomy were retrospectively analyzed. Patients were divided into two groups: group A, in which drainage tubes were not placed, and group B, in which drainage tubes were placed postoperatively. C-reactive protein, hemoglobin, and hematocrit levels; hidden, visible, and total blood losses at 24 h postoperatively; visual analog scale scores at 24, 48, and 72 h postoperatively; complications; range of motion; Western Ontario and McMaster Universities Arthritis index at 6 months postoperatively; and differences in patellar diameter, edge of tibial tubercle diameter, and ankle diameter were compared.
Results
At 24 h postoperatively, the hemoglobin and hematocrit levels in group A were significantly higher than those in group B. Total, hidden, and visible blood losses at 24 h postoperatively were significantly lower in group A than in group B. There were no significant differences in the other indices.
Conclusions
The findings suggested that using drainage tubes after high tibial osteotomy offered no evident advantages. In contrast, they increased postoperative blood loss, which is not conducive to early recovery.
Introduction
Knee osteoarthritis (OA) is a chronic degenerative bone and joint disease. 1 With an increase in the average life expectancy and aging population, the number of patients diagnosed with knee OA is gradually increasing.2,3 Single-compartment knee OA is an early stage of knee degeneration and most commonly affects the medial compartment. 4 Its main symptoms include knee pain, swelling, and limited movement. High tibial osteotomy (HTO) is an effective treatment for medial compartment OA, 5 which is often accompanied with genu varus.
HTO is a knee-preservation surgery that transfers knee weight from the medial to lateral compartment by altering the line of force of the lower limb. 6 In 1958, Jackson first used HTO to treat knee OA. 7 HTO is widely used in clinical practice due to its simplicity, low complication rate, and good postoperative recovery of knee function.8–10
HTO requires extensive soft tissue release, and the interstitial bone is cancellous; therefore, blood loss is a major concern. Due to the routine placement of tourniquets during the surgery, blood loss primarily occurs postoperatively. Studies11,12 have shown that the placement of drainage tubes can drain the fluid around the wound, thereby reducing the risk for hematoma formation around the wound. However, their placement exposes the originally closed wound to the external environment, which may result in retrograde infection. A previous study 13 has reported that placing drainage tubes increases the postoperative blood loss and hinders early rehabilitation exercises. With advances in surgical techniques and the use of tranexamic acid (TXA) and other drugs, the use of drainage tubes in orthopedic surgeries, such as total knee arthroplasty (TKA), total hip arthroplasty, and unicompartmental knee arthroplasty, has become controversial.14–16 Currently, drainage tubes are routinely placed after HTO; however, their necessity, advantages, and disadvantages require further investigation.
This retrospective study analyzed the advantages and disadvantages of postoperative drainage tube placement following HTO, focusing on postoperative pain, swelling, functional recovery of the knee joint, and complications. In addition, it also examined the necessity of postoperative drainage tube placement in terms of postoperative blood loss, complications, and functional recovery of the knee joint, thereby providing a theoretical basis for the rational use of postoperative drainage tubes in HTO procedures. We suspect that placing a drainage tube after HTO offers no obvious advantages; contrarily, it may increase postoperative bleeding and adversely affect surgical outcomes.
Methods
Patient selection
The inclusion criteria were as follows: knee OA of the medial compartment, varus deformity, and medial proximal tibial angle (MPTA) <85°; availability of complete case and postoperative follow-up data of at least 6 months; and normal coagulation profile without long-term use of oral hormones or anticoagulants.
The exclusion criteria were as follows: incomplete case or postoperative follow-up data, flexion contracture >15°, and knee range of motion (ROM) <100°.
The data of 164 patients with anterior medial compartment OA of the knee joint who underwent an initial unilateral HTO at the authors’ hospital between May 2023 and February 2024 were retrospectively analyzed. Patients were divided into two groups: group A, in which postoperative drainage tubes were not placed, and group B, in which postoperative drainage tubes were placed. This study was conducted in accordance with the Declaration of Helsinki 1975, as revised in 2024 and was approved by the Ethics Committee of the authors’ hospital (2022-141). Written informed consent was obtained from all patients. All patient details were deidentified in this study. The reporting of this study conforms to the Strengthening the Reporting of Observational studies in Epidemiology (STROBE) guidelines. 17
Surgical technique and perioperative management
All procedures were performed according to a unified clinical pathway standard, except for placement of the drainage tube.
All surgeries were performed by the same team of physicians. General or epidural anesthesia was administered based on individual patient conditions. All patients received intravenous cefazolin sodium (1.0 g) 30 min before surgery. An inflatable lower limb tourniquet was placed around the root of the thigh, and the pressure was adjusted to 45 KPa. A diagnostic knee arthroscopy was performed before HTO. If the patient had loose bodies, a meniscal injury, or intercondylar fossa stenosis, arthroscopic clearance was performed. Biplanar medial opening-wedge high tibial osteotomy (MOWHTO) was performed using a three-dimensional printed guide, as described in previous studies.18–20 A titanium plate (proximal tibial locking plate, Ruihe Medical; China) was used. TXA (1 g) was administered intravenously 10 min before tourniquet release. After releasing the tourniquet, the wound was rinsed and hemostasis was achieved. A drainage tube was placed inside the proximal incision in patients in group B; no drainage tube was used in group A. After the incision was closed, 1 g TXA was injected into the osteotomy site. Finally, elastic bandages were applied to compress the wound.
Anticoagulation therapy and infection prevention were routinely administered. Enoxaparin sodium (4000 AxaIU; Sanofi-aventis; Paris, France) was injected subcutaneously 12 h postoperatively and was continued for 4 days. Cefazolin sodium (1 g) was administered intravenously twice within 24 h of the surgery. In group B, the drainage tube was removed 24 h postoperatively. After recovery from anesthesia, the patients were instructed to perform ankle pump and straight leg elevation exercises. On postoperative day 2, the knee joint of the affected limb was allowed to flex and extend, and patients were allowed to stand on the affected limb with bedside assistance, without weight bearing. Typically, patients can bear partial weight with crutches on postoperative day 3, gradually increase weight from 4 weeks after surgery, and walk without crutches, bearing weight, 6–8 weeks after surgery, according to the situational review. 21
Clinical evaluation
Hemoglobin (Hb) and hematocrit (HCT) levels were compared between the two groups at 24 h postoperatively. Hidden blood loss, visible blood loss, and total blood loss at 24 h postoperatively were compared between the two groups. Blood volume was calculated using the Nadler formula. 22 Total, hidden, and visible blood losses were calculated using the Gross equation. 23
C-reactive protein (CRP) levels were compared between the two groups at 24 h postoperatively.
Color Doppler ultrasonography was used to monitor thrombus formation in both lower limbs at 24 h postoperatively. Simultaneously, fluid accumulation around the wound was measured using color Doppler ultrasound and expressed as volume (length × width × height).
Early postoperative pain was compared between the two groups using a visual analog scale (VAS). Pain scores of the affected limb were compared between the two groups at 24, 48, and 72 h after surgery.
Early postoperative swelling was compared between the two groups by measuring the differences in the preoperative and 72-h postoperative measurements of the patellar diameter, edge diameter of the tibial tubercle, and ankle diameter.
Functional recovery of the knee joint at 6 months postoperatively was compared between the two groups. The knee ROM and Western Ontario and McMaster Universities Arthritis Index (WOMAC)24,25 in both groups were recorded at 6 months postoperatively.
Postoperative complications were recorded in both groups, including deep vein thrombosis (DVT) of the lower limbs, hinge fracture(s), incision infection, delayed fracture union, and fracture nonunion.
Statistical analysis
The power analysis and sample size (PASS) software (version 15, NCSS, LLC; Kaysville, UT, USA) was used to estimate the required sample size. Accounting for a 20% loss to follow-up or refusal, the final minimum enrollment was set at 72 participants per group, for a total of at least 144 participants.
Statistical analyses were performed using the Statistical Package for Social Sciences (SPSS) software (version 22.0, IBM Corporation; Armonk, NY, USA) for Windows (Microsoft Corporation, Redmond, WA, USA). Measurement data with normal distribution were expressed as mean ± SD. Independent sample t-test was used to compare the two groups. Non-normally distributed measurement data were expressed as median (interquartile range (IQR), i.e. P25–P75), and the Mann–Whitney U test was used for performing between-group comparisons. Enumeration data were expressed as number of cases (percentages), and between-group comparisons were performed using the χ2 test. Differences with p <0.05 were considered statistically significant.
Results
There were no statistical differences in the basic preoperative characteristics between the two groups (sex, age, body mass index, CRP, Hb, HCT, VAS score, WOMAC index, knee ROM, hip-knee-ankle angle (HKA), MPTA, and osteotomy angle). Further details are summarized in Table 1.
Basic information of the two study groups.
M: male; F: female; BMI: body mass index; Hb: hemoglobin; HCT: hematocrit; CRP: C-reactive protein; VAS: visual analog scale; WOMAC: Western Ontario and McMaster universities osteoarthritis; ROM: range of motion; HKA: hip-knee-ankle angle; MPTA: medial proximal tibial angle.
Postoperative blood loss
There was no significant difference between the two groups in terms of surgical duration. In the drainage group, the postoperative drainage volume was 121.16 ± 57.26 mL. At 24 h postoperatively, the mean total blood loss, hidden blood loss, and visible blood loss were 276.48 ± 30.44, 212.54 ± 10.44, and 64.38 ± 9.66 mL, respectively, in group A and 441.38 ± 21.28, 252.76 ± 9.32, and 189.47 ± 11.85 mL, respectively, in group B. These differences were statistically significant (p < 0.05) between the two groups. At 24 h postoperatively, the Hb and HCT values in group A were significantly higher than those in group B (p < 0.05) (Table 2). There was no postoperative transfusion in either group.
Postoperative outcomes of the two study groups.
Hb: hemoglobin; HCT: hematocrit; CRP: C-reactive protein; VAS: visual analog scale; WOMAC: Western Ontario and McMaster universities osteoarthritis; ROM: range of motion.
Comparison of the perioperative CRP levels between the two groups
There was no significant difference in preoperative CRP levels between the two groups (t = 0.611, p = 0.542) (Table 1). Furthermore, there was no significant difference in CRP levels at 24 h postoperatively between the two groups (t = 1.274, p = 0.205) (Table 2). However, there was significant difference in CRP levels between the preoperative and 24 h postoperative measurements in group A (t = 16.98, p < 0.0001) and group B (t = 17.02, p < 0.0001).
Early pain, swelling, and fluid accumulation around the wound
There were no statistical differences in the VAS scores at 24, 48, and 72 h postoperatively between the two groups (p > 0.05). The mean volume of fluid accumulation around the wound at 24 h postoperatively was 3.39 ± 0.39 cm3 in group A and 2.53 ± 0.32 cm3 in group B, with no statistically significant differences between the two groups (p > 0.05). Furthermore, there were no statistical differences in the preoperative patellar diameter, edge of the tibial tubercle diameter, and ankle diameter between the two groups at 72 h postoperatively. Further details are summarized in Table 2.
Knee function recovery
All patients were followed up for at least 6 months. By 6 months postoperatively, the bone at the osteotomy site was healed completely, the genu varus deformity was corrected, and the alignment of the lower limb was improved (Figure 1). Six months postoperatively, there were no significant differences in the ROM and WOMAC scores between the two groups (p > 0.05). Further details are summarized in Table 2.

Radiological evaluation. The patients were examined using anteroposterior and lateral knee joints and full-length X-rays of both lower limbs before and after the surgery. (a) Preoperative anteroposterior knee X-ray; (b) preoperative lateral knee X-ray; (c) preoperative full-length X-ray of both lower extremities; (d) postoperative anteroposterior knee X-ray; (e) postoperative lateral knee X-ray; and (f) postoperative full-length X-ray of both lower extremities. The deformity of genu varus was corrected, and the alignment of the lower limb was improved after the surgery.
Complications
There were 10 postoperative complications in group A: hinge point fracture(s) (n = 5), DVT of the lower extremity (n = 3), and delayed healing (n = 2). Postoperative complications occurred in 8 patients in group B: wound infection (n = 3), hinge point fracture (n = 3), and DVT (n = 2). There was no significant difference in the incidence of postoperative complications between the two groups (χ2 = 0.250, p = 0.617). All the above complications in both groups resolved without serious consequences.
Discussion
Several factors influence the outcomes of HTO. There are no consensus or guidelines regarding whether a drainage tube should be placed after HTO. The decision of using a drainage tube following the procedure should be based on its benefits for rehabilitation of the affected limb and joint function. Based on the results of the present study, not using a drainage tube after HTO had no significant effects on postoperative pain, swelling, joint function, and complications. In contrast, the placement of a drainage tube increased the volume of postoperative blood loss, which was not conducive to early postoperative rehabilitation exercises.
In terms of postoperative blood loss, patients who underwent HTO were older and had reduced compensatory capacity. During surgery, biplanar osteotomy was performed, and blood accumulated in the operative area and penetrated the tissue space. Therefore, the possibility of postoperative blood loss should be taken into consideration. This study demonstrated that at 24 h postoperatively, the Hb and HCT levels in the drainage group were significantly lower than those in the nondrainage group. Total blood loss, hidden blood loss, and visible blood loss at 24 h postoperatively were significantly higher in the drainage group than those in the nondrainage group. These findings highlight that although the placement of drainage tubes reduced pressure in the operative area by draining accumulated blood, it also increased the risk for postoperative bleeding. Previous studies have shown that the placement of drainage tubes in the operative area can not only drain the hematoma but also lose the tamponade effect of the hematoma, increasing the risk for postoperative blood loss.13,26 In addition, when the drainage tube was placed after HTO, the effect of compression from the elastic bandage was lost, and bleeding was further aggravated.
CRP, synthesized by the liver, is a sensitive indicator of inflammation and tissue damage in the body. Although its specificity is low, it can dynamically evaluate the process of inflammation in the body. 27 In this study, CRP levels increased in both groups at 24 h postoperatively compared with the preoperative levels, with no significant differences between the two groups before and 24 h after surgery. These results indicate that HTO surgery may cause tissue damage and increase inflammatory response; however, the placement of a drainage tube does not affect its state.
It has been reported that not using drainage in TKA can reduce postoperative pain. 28 The presence of a drainage tube may stimulate the skin and deep tissues, leading to sensory sensitization and ultimately a lower pain threshold. 12 However, there is considerable controversy regarding the use of a drainage tube in HTO. Drainage in TKA is placed intra-articularly, whereas drainage in HTO is placed at lower limb. A high-level randomized controlled trial (RCT) by Li et al. 12 reported advantages of drainage in HTO; however, there were some limitations to this study. The sample size was relatively small, and the follow-up duration was only approximately 3.2 months. Additionally, it only assessed the effect of drainage on total blood loss, without evaluating the specific effects on hidden and visible blood losses. More importantly, thrombotic complications, such as DVT and pulmonary embolism, were not evaluated. Although our study was retrospective in nature, the aforementioned limitations were avoided. Our sample size was larger, and the follow-up period was longer. Additionally, hidden, visible, and total blood losses were evaluated, and thrombotic complications such as DVT were observed.
Studies6,12 have shown that placing drainage tubes after HTO can reduce swelling of the affected limb and accumulation of fluid around the wound; therefore, routine placement of drainage tubes after HTO is recommended. However, the findings of the present study were not consistent with these reports. In the present study, the VAS scores at 24, 48, and 72 h postoperatively were not significantly different between the two groups, suggesting that drainage placement after HTO did not affect early postoperative pain levels. Color Doppler ultrasonography was used to measure fluid accumulation around the wound. Additionally, differences in preoperative patellar diameter, edge of the tibial tubercle diameter, and ankle diameter were measured at 72 h postoperatively. The results revealed that the absence of drainage did not result in increased fluid accumulation or wound swelling. This may be attributed to advances in surgical technologies, the use of TXA, 29 and early postoperative rehabilitation exercises.
In terms of knee function recovery, the knee WOMAC index is a reliable tool for evaluating joint function and effects after knee surgery. 24 The severity of arthritis and effectiveness of treatment were assessed based on the relevant signs and symptoms of the patient. The structure and function of the knee joint were evaluated based on pain, stiffness, and joint function. 25 The results of this study showed no statistically significant differences in the WOMAC index scores and ROM between the two groups at 6 months postoperatively. Drainage placement after HTO surgery did not affect the recovery of knee joint function.
Common postoperative complications of HTO include infection of the operative area and incision, peroneal nerve injury, DVT, hinge fracture, plate loosening, and other fractures. The results of this study demonstrated no significant difference in the incidence of postoperative complications between the two groups. Previous investigators generally believed that the placement of drainage tubes in the operative area can prevent the formation of a hematoma and reduce the accumulation of fluid around the wound, thereby reducing the occurrence of postoperative infection. However, there was no statistically significant difference in the incidence of wound infection between the two groups in our study, which may be explained by the compression of the elastic bandage, use of TXA, 30 and rehabilitation education.
The present study had certain limitations. First, all the patients’ drainage tubes were removed on postoperative day 1. Further studies should investigate the effects of different retention times of the drainage tubes on blood loss, pain, and joint function recovery after HTO. Second, this was a single-center retrospective study with a relatively small sample size. For events with a lower incidence rate, such as DVT and incision complications, a larger sample size is required to draw reliable conclusions. Third, due to the limitations associated with the follow-up period, we were unable to compare the long-term recovery of knee joint function and the occurrence of complications such as infection and delayed healing at the osteotomy site. Therefore, future prospective, multicenter randomized controlled studies with larger sample sizes are warranted.
Conclusion
The placement of a drainage tube after HTO had no significant effect on postoperative pain, swelling, functional recovery of the knee joint, or complications. Therefore, there may be no evident advantage associated with the use of a drainage tube after HTO. In contrast, the use of a drainage tube may increase postoperative blood loss, which is not conducive to early recovery.
Footnotes
Acknowledgments
We would like to thank the nursing term of Digital Orthopedic technology clinical application center, Tianjin Hospital, for the support, and our patient for participating in this study.
Author contributions
Bin Zhao and Xinlong Ma contributed to the conception and design of the study. Qian Zhao and Songqing Ye contributed to the analysis and interpretation of the date. Bin Zhao and Qian Zhao contributed to the drafting of manuscripts. Haohao Bai and Bin Zhao contributed to the carry out of the experiments. All the authors read and approved the manuscript.
Data availability statement
All data supporting the findings of this study are available within the paper.
Declaration of conflicting interests
No conflict of interest exits in the submission of this manuscript.
Funding
This study was sponsored by the Tianjin health industry high-level talent selection and training project, Young medical new talent (TJSQNYXXR-D2-136), Tianjin Health Research Project (TJWJ2023QN049).
