Biomechanical Assessment of Patients with Unilateral Total Knee Arthroplasty: A Preliminary Comparative Study

Abstract

Aims: To identify the biomechanical differences between two types of prostheses (posterior-stabilized prosthesis with a fixed tibial plateau base and congruent prosthesis with a rotating tibial plateau) through functional performance measured by the 2-Minute Walk Test using the G-Sensor® inertial sensor (BTS Bioengineering S.p.A., Italy). Study Design: A prospective, observational, and comparative study with assessments conducted at two time points: 12 to 24 months after surgery. Place and Duration of Study: This study was carried out in a tertiary hospital in collaboration with a private university in the state of Goiás, Brazil, between March 2022 and December 2024. Methodology: This study evaluates and compares the functional performance of a sample of 36 patients using the 2-Minute Walk Test (2MWT) with an inertial sensor at two distinct time points, 12 to 24 months postoperatively. Patients were characterized by age, sex, BMI, postoperative time, laterality of the operated knee, and type of prosthesis used (fixed plateau or mobile plateau). Results: The study included 36 participants (21 women and 15 men; mean age 69.38 years, BMI 30.46), with 24 undergoing right knee arthroplasty. Half received fixed, and half rotated tibial plateau prostheses. Postoperative assessments at 17.31 and 42.80 months showed no significant differences in gait parameters between prosthesis types or sides. Pearson’s correlation revealed a strong negative relationship between test duration, cadence, and speed for rotating prostheses (r = -0.67/-0.66, P =.001) and between duration and speed for fixed prostheses (r = -0.8, P<.001). Conclusion: This study found no significant functional differences between fixed and rotating tibial plateau prostheses using the 2-Minute Walk Test. Both implants effectively restored knee mobility, emphasizing the utility of inertial sensors for clinical assessment. Further research with larger samples is needed to confirm these findings.