Determination of restoration of posterior condylar offset along with an analysis of risk of anterior femoral notching in total knee replacement by utilizing posterior referencing techniques

Abstract

Objectives: Total knee replacement surgery has been the definitive management for any type of severe grade osteoarthritis. Anterior referencing and posterior referencing are two definitive techniques for positioning the femoral components and balancing the sagittal plane during the surgery of total knee replacement (TKR). The purpose of this study was to evaluate the changes in medial and lateral posterior condylar offset (PCO) after TKR using posterior referencing (PR) system. Literature shows that posterior referencing accurately restores posterior condylar offset relative to anterior referencing. However, there are still chances of anterior femoral notching and this anterior femur notching in turn may lead to periprosthetic fracture. Various studies have shown that anterior referencing technique affects the flexion gap tightness. This particular study is intended to assess the restoration of posterior condylar offset and the chances of anterior femoral notching in total knee replacement using posterior referencing technique by analyzing the pre-operative and post-operative knee x-ray in a true lateral view. Materials and Methods: This was a prospective observational study of 50 consecutive cases of severe knee joint osteoarthritis. Posterior condylar offset was measured using picture archiving and communication systems (PACS). Post-operative X-rays of knee joint in their true lateral views were analyzed for anterior femoral notching. Results: In 49 knee replacements, Posterior Condylar Offset was restored within 0 cm to +0.3 cm. In one case, however the PCO increased beyond +0.3cm. None of the cases witnessed a decline in PCO. No Anterior Femoral Notching was seen in any of the cases. Hence, restoration was observed to be a very common phenomenon. Conclusion: This study concludes that in total knee replacement using posterior referencing technique, Posterior Condylar Offset is restored in majority of the cases and chances of Anterior Femoral Notching are negligib