Evaluation of the Cementation Index as a Predictor of Failure in Coonrad-Morrey Total Elbow Arthroplasty

Background. The aim of this study is to objectively evaluate the quality of cementation by a novel method called the cementation index and assess its utility as a predictor of failure. Materials and Methods. Fifty elbows with primary Coonrad-Morrey total elbow replacement were included. The quality of cementing was assessed by novel methods, the vertical and horizontal cementation index, which were statistically evaluated as predictors of failure. The mean period of followup was 8.08±2.95 years (range: from 5.08 to 10.25 years). Results. The mean vertical cementation index of the humerus (vCIH) was 1.22 ± 0.28 and that of the ulna (vCIU) was 1.10±0.18. Radiolucent zones were noted in two cases in the humerus with a horizontal cementation index of 0.21 and 0.14, respectively. Both of the cementation indices were not found to be statistically significant predictors of failure (P>0.05). The five-year survival rate was 94%. Discussion and Conclusion. The cementation index, being a ratio, reduces the confounding effect of taking radiographs in different positions of the limb with different magnification in followup radiographs. It is an easy and objective method of assessment of cementation, the results of which need to be validated by a larger study.