Prospective study of posterior condylar offset ratio and its influence on maximal flexion angle of knee in posterior cruciate ligament substituting total knee arthroplasty

Abstract

Background: Osteoarthritis of the knee is a common clinical problem that affects elderly and few young individuals. It is associated with symptoms like pain, stiffness and limitation of activity. Total Knee Arthroplasty is an effective surgical modality that reduces pain, improves patients' quality of life, and increases functional capability in patients with severe osteoarthritis of knee. Role of Posterior Condylar Offset on Range of movements has always been a controversial topic. The present study has been taken up by us because studies conducted by western authors reported conflicting outcomes. Materials and Methods:This was a prospective study in which Patients with diagnosis of osteoarthritis knee presenting in Department of Orthopaedics at a tertiary care hospital and willing to undergo surgery were included depending upon inclusion and exclusion criteria. Assessment of knee was done preoperatively and postoperatively to obtain functional outcome of TKA clinically by using knee society score and oxford knee score and radiologically to obtain PCO and PCOR. Results: We found no significant correlation between post-operative Posterior Condylar Offset (mean 25.94+/-1.89), Posterior Condylar Offset Ratio (mean 0.45+/-0.02) with Maximum Flexion Angle (mean115.93+/-9.59) with p value 0.136 and 0.995 respectively. Conclusion: Maximum flexion angle after Total Knee Arthroplasty is a multivariate hence Posterior Condylar Offset and Posterior Condylar Offset Ratio cannot be used as an independent variable for the quantification of functional outcome of Total Knee Arthroplasty. Moreover, accurate radiographic measurement of pre-operative Posterior Condylar Offset is not possible as the cartilage thickness remained was not accounted for and also there is an inherent error in the measurement techniques that accounts for inconsistent findings.