Abstract
Successful total knee arthroplasty design is related to the joint dynamics imposed by the design. This study examined the clinical and biomechanical performance of patients who received a PFC Sigma total knee implant (posterior cruciate substituting design). Radiographic, strength testing, gait pattern and clinical survey data were collected. Pre-operative and post-operative outcome measures were compared. Statistically significant differences were found on the pain, stiffness and physical function scales of the WOMAC as well as the knee and total score parameters of the Knee Society Score. Significant improvements were also seen on several gait pattern parameters.
Factors such as implant design and surgical technique have been found to influence knee kinematics and kinetics thereby effecting patient function and implant survival after total knee arthroplasty. Numerous gait studies have reported a lack of normal gait pattern for TKA patients (Wilson et al., 1996; Andriacchi, 1993; Jevsevar et al., 1993). There is debate in the literature as to which design best improves patient function and implant survival, the posterior cruciate (PC) substituting or PC-retaining. The purpose of this study is to determine the clinical outcome and biomechanical performance of patients who receive PFC Sigma total knee arthroplasty.
The PC substituting implant design provided significant improvements in clinical and gait outcomes at two years post-op in this patient sample.
Patients experience significant pain and stiffness relief, and better functional outcomes.
A cohort of eighteen total knee replacement patients were followed for two years post-operatively. Radiographic, strength testing, gait pattern and clinical survey data (SF36, WOMAC, Knee Society Score) were collected. Paired sample t-tests, repeated measures general linear modeling and principle component analyses comparing aged matched normals were conducted to evaluate pre-operative and post-operative outcomes. Statistically significant differences were found on the pain, stiffness and physical function scales of the WOMAC as well as the knee and total score parameters of the Knee Society survey. There were also significant improvements found on gait pattern parameters. Findings like these point to a need for larger population studies of patients with PC-substituting TKA.
Funding: Funding for this study was provided by Depuy Orthopaedics, Inc.
Correspondence should be addressed to Cynthia Vezina, Communications Manager, COA, 4150-360 Ste. Catherine St. West, Westmount, QC H3Z 2Y5, Canada
