Computer aided densitometric image analysis of bone remodelling after total hip arthroplasty

By means of a simple and inexpensive system, the computer aided densitometric image analysis (CADIA), we can now evaluate on X-ray film the effect of long term bone remodelling after total hip arthroplasties (THA). The results of CADIA system applied to the historical archive are burdened by a not always acceptable significance. The main source of error is the variance of radiological parameters. An attempt to retrieve the historical archive, that is of every X-ray film obtained out of any radiological control protocol, can be carried out with the bone density ratio representation. We have evaluated three different specimens with bone density ratio analysis: cementless group (96 cases), cemented group (59 cases) and non prosthetized femurs group (51 cases) as a control, all groups were followed up for more than 24 months. Ratios showed up different behaviour among the three specimens, confirming clinical evidence of a lower bone remodelling for cemented THA.