Evaluation of braking performances of patients with osteoarthritis of the knee or hip: Are there alternatives to a brake simulator?

Özet

Objective: This study aims to develop and evaluate a simple tool for daily practice that might allow a rough estimate of individual brakingperformance (brake response time, BRT) of patients with osteoarthritis or those with arthroplasty of the knee or hip.Methods: In this cross-sectional study, we examined 162 patients (72 men, 90 women; mean age = 64±12.8 years) who suffered fromosteoarthritis of the knee (n=45) or hip (n=64) or who underwent a total hip (n=37) or knee (n=16) arthroplasty. BRT of each patient wasmeasured in a brake simulator. The results were compared to demographic data, various clinical tests, and pain surveys. From these data,a multiple linear regression model was developed.Results: From the observed correlations, the regression model consisted of age (correlation with BRT τ=0.176, p=0.001), sex (τ=0.361,p<0.001), Hau’s step test (τ=-0.345, p<0.001), and the pain dimension of the Hip disability/Knee injury and Osteoarthritis Outcome Score(τ=-0.265, p<0.001). We, therefore, suggested the following formula: BRTest = 634.8 - (8.8 x Hau) + 119.2 (for women) + (3.0 x age) - (1.3 xH/KOOS Pain). The above-mentioned variables contributed significantly to the prediction of BRT and could achieve a multiple R² adj of0.31. The model leaves a residual standard error (i.e., SD of the residuals) of 158.4 ms, which is superior to a model without predictors; F(4.140)=16.8, p<0.001.Conclusion: Our evaluated regression model offers an uncertainty which is comparable to the one based on a fixed time period aftersurgery or a defined pathologic condition. The high variability even within a single patient over several brake simulator measurementsmakes it unlikely for a model to be generated solely based on clinical testing. Taking the available data in literature into account, we advisecaution when formulating a real-time- or condition-based recommendation. We rather suggest being aware of risk factors that might leadto impaired BRT to sensitize patients to their impaired ability to drive. We identify such risk factors, namely old age, female sex, impairedmusculoskeletal function, as tested in Hau’s step test, and high levels of pain.Level of Evidence: Level III, Therapeutic Study