Abstract
The quality of femoral stem cementation has been shown to be a useful indicator of long-term survival of the total hip arthroplasty. Barrack's cementation grading is widely used but has certain limitations. It is based upon second-generation cementation technique and has high inter- and intra-observer variability. We introduce a new femoral cementation index based upon lengths of radiological lucency and cement-bone interface on AP and lateral views.
Five observers graded femoral cementation of radiographs of 30 primary hip arthroplasties using Barrack's grading and the new index on two occasions and Inter- & Intra-observer reliability was assessed. We also assessed the correlation between proximal femoral anatomy (calcar-canal ratio) & structural bone quality (using cortical index) with cementation using the new index in 50 patients.
Inter- and intra-observer reliability of the new index showed intraclass correlation coefficient 0.79 and 0.82 respectively and Barrack's grading system showed Kappa value- 0.20 (inter-observer) and 0.55 (intra-observer) reliability.
There was poor correlation between the calcar-canal ratio and the quality of cementation [Pearson's coefficient −0.04 (p< 0.05)]. There was some correlation between the cortical index and the quality of cementation [Pearson's coefficient 0.46 (p < 0.05)].
Our new index is a reliable method of assessing femoral cementation. The anatomy of femoral canal didn't have any significant influence on the quality of cementation achieved as assessed by our new index. The femoral cortical structural quality seemed to have some positive influence on the quality of cementation.
