Summary

Not only postoperative muscle strength and walking status, but also preoperative muscle strength and the walking status influence midterm patients' satisfaction, expectation and functional activities after TKA.

Abstract

Introduction

Total knee arthroplasty (TKA) is one of the most successful treatment with respect to relieving pain and restoring function of the knee. However, several studies have reported that only 75% to 89% patients are satisfied with their results after TKA. Correlation between longitudinal athletic ability and midterm patient satisfaction after TKA are not well known. The purpose of this study was to determine whether athletic ability including muscle strength, balance ability and functional mobility before and after TKA influence midterm patients' expectations and satisfaction after TKA.

Materials And Methods

We evaluated 39 osteoarthritic knees in 34 primary TKA patients. We assessed patient-reported scores using the 2011 Knee Society Scoring System over 24 month (average 41.5 month, 24-61 month) after TKA. We measured the 3m timed up-and-go test (TUG), one leg standing time, and knee flexor and extensor strength before TKA and 6 months after TKA. We assessed the correlation between the patient-reported scores and each values using Spearman's coefficients of correlation. Analyses were performed with JMP statistical software v11.0 (SAS Institute, Tokyo, Japan). A p-value < 0.05 was considered to indicate statistical significance.

Results

Patient satisfaction was significantly correlated with preoperative extensor strength (r=0.51, p<0.001) and 6M flexor strength(r=0.51, p<0.001). Patient expectations was significantly correlated with 6M flexor strength (r=0.67, p<0.001), 6M TUG(r=0.62, p<0.001) and preoperative extensor strength (r=0.51, p<0.001). Functional activities were significantly correlated with preoperative TUG (r=0.57, p<0.001), 6M TUG (r=0.57, p<0.001) and preoperative flexor strength (r=0.54, p<0.001).

Discussion And Conclusion

Our study demonstrates that not only 6M TUG and muscle strength, but also preoperative TUG and muscle strength is highly correlated with midterm patient satisfaction after TKA.
Preoperative extensor strength and 6M flexor strength predicts patient satisfaction. 6M flexor strength, TUG and preoperative extensor strength predict patient expectation. Preoperative and 6M TUG, and preoperative flexor strength predict functional activities. These result suggest that muscle strength training before TKA, or early indication of TKA before muscle weakness may improve patient satisfaction.