Effect of Patient Specific Instrumentation on Kinematics in Total Knee Replacements

Introduction: Currently, the only treatment for end stage arthritis in the knee is total knee replacement (TKR). Even though TKR has improved over the years, with implants having greater longevity, patient satisfaction following TKR has not improved, with approximately 20% of patients recording dissatisfaction with their new knee joint. Manufacturers have attempted to solve this issue with patient specific instrumentation (PSI), custom surgical guides designed pre-operatively using MRI or CT scans. However, no consensus has been reached on the effectiveness of PSI. With the use of radiostereometric analysis (RSA), the current study aims to analyze the knee throughout flexion when PSI is used to determine whether PSI provides an improvement to TKR. We hypothesize that using PSI will provide a more stable knee consistent with more natural kinematics throughout flexion than conventional instrumentation (CI).