Can Preoperative Characteristics Identify Patients Whose Walking Speed Will Increase or Decrease by at Least 10% after Bilateral TKA?

Q: Can it be applied directly to individual patients' treatment decisions?

This retrospective study was limited to women undergoing staged bilateral TKA. The abstract reports no external validation, so performance in other sexes or unilateral TKA cannot be assessed.

Mean walking speed increased by 0.07 m/s, from 0.87 to 0.94 m/s (P < 0.001).

Research structure

01
Subject
128 women who received a stage-by-stage primary TKA.
02
Methods
A retrospective cohort of staged bilateral TKA compared gait before surgery and at 2 years. Groups were defined by an increase or decrease of at least 10%, or an intermediate change; a classifier used walking speed, age and mechanical-axis angle.
03
Reported Results
Mean walking speed increased by 0.07 m/s, from 0.87 to 0.94 m/s (P < 0.001).

An explanatory schematic separating the study population, methods, and results. It is not an original paper figure.

Evidence & Original Source

Abstract commentary

Participants and Methods

A retrospective cohort of staged bilateral TKA compared gait before surgery and at 2 years. Groups were defined by an increase or decrease of at least 10%, or an intermediate change; a classifier used walking speed, age and mechanical-axis angle. 128 women who received a stage-by-stage primary TKA.

Main Findings

Mean walking speed increased by 0.07 m/s, from 0.87 to 0.94 m/s (P < 0.001). Speed increased by at least 10% in 56 patients (43.8%) and decreased by at least 10% in 17 patients (13.3%). The model using preoperative walking speed, age and mechanical-axis angle had a ROC AUC of 0.86.

The point of reading on surgery

This supports assessing pain or alignment improvement separately from recovery of walking speed. Gait tests may explain individual differences in postoperative function, but this model alone does not establish when to operate.

Limitations

This retrospective study was limited to women undergoing staged bilateral TKA. The abstract reports no external validation, so performance in other sexes or unilateral TKA cannot be assessed.

Let's put it briefly.

What did this study confirm?

Mean walking speed increased by 0.07 m/s, from 0.87 to 0.94 m/s (P < 0.001).

Can it be applied directly to individual patients' treatment decisions?

This retrospective study was limited to women undergoing staged bilateral TKA. The abstract reports no external validation, so performance in other sexes or unilateral TKA cannot be assessed.

Keywords

Gait analysis
Gait speed
Total knee arthroplasty
Arthroplasty, Replacement, Knee
Machine Learning
Walking Speed
Retrospective Studies
Recovery of Function

Abstract · Original text

Do Weon Lee, Hyuk-Soo Han, Myung Chul Lee, Du Hyun Ro. Prediction of postoperative gait speed change after bilateral primary total knee arthroplasty in female patients using a machine learning algorithm. Orthopaedics & traumatology, surgery & research : OTSR. 2024;110(7):103842. doi:10.1016/j.otsr.2024.103842.

BACKGROUND

An important aim of total knee arthroplasty is to achieve functional recovery, which includes post-operative increase in walking speed. Therefore, predicting whether a patient will walk faster or slower after surgery is important in TKA, which has not been studied in previous literatures. Who walks faster and who walks slower after TKA? Can we predict these kinds of patients before surgery?

HYPOTHESIS

Whether or not a patient walk faster after total knee arthroplasty can be predicted with preoperative characteristics.

PATIENTS AND METHODS

In this retrospective cohort study, 128 female patients who underwent staged bilateral total knee arthroplasty were analyzed with gait analysis preoperatively and at postoperative two years. These patients were divided into three different groups according to the percentage of gait speed change after total knee arthroplasty: 1) V(+), more than 10% gait speed increase; 2) V(-), more than 10% gait speed decrease; and 3) V(0), those in-between. Gait parameters, mechanical axis angles, WOMAC pain score and Knee Society scores of the two groups (V(+) and V(-)) were compared. Furthermore, a classification model predicting whether a patient walks faster after total knee arthroplasty was designed using a machine learning algorithm.

RESULTS

After total knee arthroplasty, average gait speed increased by 0.07m/s from 0.87m/s to 0.94m/s (p<0.001) and gait speed increased in 43.8% of the patients (n=56). However, gait speed decreased in a significant number of patients (n=17, 13.3%). When V(+) and V(-) groups were compared, gait speed, cadence, sagittal/coronal knee range of motion, and Knee Society Function score were lower in the V(+) group before surgery, but became higher after surgery. Gait speed change could be predicted using three variables (preoperative gait speed, age, and the magnitude of mechanical axis angle). The area under the receiver operating characteristic curve of the machine learning model was 0.86.

DISCUSSION

After total knee arthroplasty, gait speed was maintained or increased in most patients. However, gait speed decreased in a significant number of patients. The machine learning classification model showed a good predictive performance, which could aid in the decision-making and the timing of total knee arthroplasty.

LEVEL OF EVIDENCE

III; retrospective cohort study.

Read abstract on PubMed

The original paper.

Prediction of postoperative gait speed change after bilateral primary total knee arthroplasty in female patients using a machine learning algorithm

Do Weon Lee, Hyuk-Soo Han, Myung Chul Lee, Du Hyun Ro
Orthopaedics & Traumatology: Surgery & Research · 2024

DOI · 10.1016/j.otsr.2024.103842 PubMed Based data

The first one examined.