Abstract
Introduction
The aim of this study was to see if the evaluation of the initial postoperative radiograph following primary knee and hip arthroplasty correlated with clinical outcome at five years postoperatively.
Methodology
Using our institution database we identified forty-nine hip replacements and fifty-two knee replacements performed between 2000 and 2006. All the patients underwent postoperative radiographs one day after surgery and clinical evaluation up to at least five years postoperatively. A consultant radiologist evaluated the radiographs for alignment and component position. The hip arthroplasty patients were assessed clinically using the Harris hip score, Oxford hip score, and the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC). The knee arthroplasty patients were assessed using the Knee Society score, Oxford knee score, and the WOMAC score.
Results
In the hip group a significant positive linear relationship was found between the superior measurement for location of the centre of rotation of hip relative to teardrop and the Oxford hip score at 5 years, as well as the WOMAC hip score, and between cup inclination and the WOMAC Hip score at a minimum of five years follow-up. The acetabular cup inclination was found to be significantly related to functional outcome as measured by the WOMAC hip score at a minimum of five years follow-up with unadjusted regression analysis.
In the knee group there was no significant relationship found between radiographic findings and functional outcome as measured by the Knee Society score and Oxford knee score. Correlation analysis revealed a significant negative relationship between anteroposterior tibial lucency and functional outcome as measured by the WOMAC knee score at a minimum of five years follow-up.
Conclusion
Further studies would be required with a larger sample size to evaluate possible relationships identified by this study, to develop an assessment tool to predict outcomes of arthroplasty procedures.
