Introduction: Patients may experience knee stiffness following total knee arthroplasty (TKA). Non-operative measures, such as more physical therapy and special splints are warranted in such cases. In the event of failure of these measures to restore knee range of motion, more invasive procedures with higher risks, such as manipulation under anesthesia (MUA) or repeat surgery, can be utilized. Thus, it becomes essential to optimize their non-operative measures in order to avoid more invasive, riskier options. Therefore, the purpose of this study was to evaluate and compare: 1) range of motion, and 2) the rate of MUA in patients who either underwent a multi-modal physical therapy regimen (IMMPT) or standard-of-care post-operative therapy (standard) following primary total knee arthroplasty.
Materials and methods: We analyzed all non-obese patients who underwent primary TKAs between January 2013 and December 2014 at our institution who started an outpatient physical therapy program within six weeks of their surgery (n = 127 knees). There were 86 women and 41 men who had a mean age of 67 years (range, 42 to 88 years). This cohort was stratified into those who underwent an IMMPT regimen at our institution (n= 47) and those who underwent standard therapy at an outside institution (N = 80). The range of motion and rate of manipulation between the two groups was compared by using Chi-square and Student's t-test, as appropriate.
Results: There were similar proportions of those who had an optimal range of motion (≥110 degrees flexion and ≤5 degrees extension) in the IMMPT group as compared to the standard physical therapy cohort (81% vs. 82%). The IMMPT cohort had a significantly lower proportion of patients who underwent MUA as compared to the standard therapy cohort (2% vs. 13%).
Conclusions: This study shows an IMMPT protocol utilizing Astym® therapy (Performance Dynamics, Inc. Muncie, Indiana) is able to significantly reduce the rate of manipulation following a total knee arthroplasty. Furthermore, this IMMPT approach was also able to achieve similar range of motion to the standard physical therapy group while reducing the rate of manipulation, which may indicate similar efficacy in restoring range of motion. Comparative randomized studies are needed to determine the true benefit of this IMMPT protocol.