Early ambulation after total knee arthroplasty: a retrospective single-center study
Authors: Zhou Guanjie , Yao Yao , Shen Ying , You Xiaokang , Zhang Xiaofeng , Xu Zhihong 
Published: July 2024

Abstract
Purpose
Early ambulation is an important step in accelerating post-joint replacement surgery recovery. However, there is limited research on populations who are unable to walk immediately after the operation. The purpose of this study was to determine the factors influencing postoperative ambulation in total knee arthroplasty (TKA) patients.

Methods
Primary TKA patients were included in this retrospective study. All patients were divided into two groups. Patients who began walking within 24 h were categorized as the early ambulation group, while patients who began walking after 24 h were classified as the late ambulation group. Recorded demographic data included age, gender, body mass index (BMI), clinical diagnosis, and comorbidities. Hematological parameters potentially affecting patients’ preoperative physical condition were also documented. Additionally, intraoperative metrics such as surgical time, surgical side, tourniquet time, intraoperative blood loss, the placement of drains, and prosthetic model were recorded.

Results
A total of 453 patients (79.0% female, 21.0% male) were included in this study. The average age of all patients was 68.5±7.9 years, ranging from 36 to 87 years, with an average BMI of 27.2±9.9 kg/$$\mathrm {m^{2}}$$

m
2

. The mean postoperative ambulation time was 1.6 days, with a range of 0–4 days. In univariate group comparisons, an increase in postoperative time to ambulation was significantly associated with a history of heart disease ($$P<0.001$$

P
<
0.001

), stroke history ($$P=0.003$$

P
=
0.003

), and prior surgeries ($$P=0.003$$

P
=
0.003

). Patients who delayed ambulation also exhibited significantly higher coagulation-related parameters including PT ($$P<0.001$$

P
<
0.001

), APTT ($$P=0.002$$

P
=
0.002

), TT ($$P=0.039$$

P
=
0.039

) before surgery compared to those who mobilized early. Furthermore, prolonged surgical time ($$P= 0.030$$

P
=
0.030

), increased intraoperative blood loss ($$P<0.001$$

P
<
0.001

), and the placement of intraoperative drains ($$P<0.001$$

P
<
0.001

) also significantly extended the time to postoperative ambulation. However, after multivariate logistic regression analysis, only PT (OR 1.86, 95% CI 1.32$$-$$
-
2.61, $$P<0.001$$

P
<
0.001

), TT (OR 1.30, 95% CI 1.09$$-$$
-
1.55, $$P=0.004$$

P
=
0.004

) intraoperative blood loss (OR 1.01, 95% CI 1.00$$-$$
-
1.01, $$P=0.008$$

P
=
0.008

) and the placement of intraoperative drains (OR 11.39, 95% CI 6.59$$-$$
-
19.69, $$P<0.001$$

P
<
0.001

) were identified as predictive factors for late ambulation in patients after TKA.

Conclusion
In this study, preoperative coagulation function, intraoperative blood loss and the placement of intraoperative drains were factors contributing to delay ambulation time. Therefore, it is believed that properly improving preoperative coagulation function, effective intraoperative hemostasis, and reducing the placement of drains have a positive impact on early postoperative ambulation in patients undergoing TKA.