Carmelo Messina1, Federico Giuseppe Usuelli2, Camilla Maccario2, Claudia Angela Di Silvestri2, Salvatore Gitto3, Maria Cristina Cortese4, Domenico Albano2, Luca Maria Sconfienza5. 1. IRCCS Istituto Ortopedico Galeazzi, via Riccardo Galeazzi 4, 20161 Milan, Italy; Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, via Carlo Pascal, 36, 20133, Milan, Italy. Electronic address: carmelo.messina@unimi.it. 2. IRCCS Istituto Ortopedico Galeazzi, via Riccardo Galeazzi 4, 20161 Milan, Italy. 3. Scuola di Specializzazione in Radiodiagnostica, Università degli Studi di Milano, Via Festa del Perdono, 7, 20122 Milan, Italy. 4. Radiologia Diagnostica e Interventistica Generale, Area Diagnostica per Immagini, Dipartimento Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, IRCCS Fondazione Policlinico Universitario A. Gemelli, Roma, Italia; Istituto di Radiologia, Università Cattolica del Sacro Cuore, Roma, Italia. 5. IRCCS Istituto Ortopedico Galeazzi, via Riccardo Galeazzi 4, 20161 Milan, Italy; Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, via Carlo Pascal, 36, 20133, Milan, Italy.
Abstract
INTRODUCTION: Joint prosthesis survival is associated with the quality of surrounding bone. Dual-energy X-ray absorptiometry (DXA) is capable to evaluate areal bone mineral density (BMD) around different prosthetic implants, but no studies evaluated periprosthetic bone around total ankle replacement (TAR). Our aim is to determine the precision of the DXA periprosthetic BMD around TAR. METHODOLOGY: Short-term precision was evaluated on 15 consecutive patients. Each ankle was scanned 3 times both in the posteroanterior (PA) and lateral views with a dedicated patient positioning protocol. Up to four squared regions of interest (ROIs) were placed in the periprosthetic bone around tibial and talar implants, with an additional ROI to include the calcaneal body in the lateral scan. Coefficient of variation (CV%) and least significant change were calculated according to the International Society for Clinical Densitometry. RESULTS: The lateral projection showed lower mean CV values compared to the PA projection, with an average precision error of 2.21% (lateral scan) compared to 3.34% (PA scans). Overall, the lowest precision error was found at both "global" ROIs (CV = 1.25% on PA and CV = 1.3% on lateral). The highest CV value on PA was found at the medial aspect of talar side (ROI 3; CV = 4.89%), while on the lateral scan the highest CV value was found on the posterior aspect of talar side (ROI 2; CV = 2.99%). CONCLUSIONS: We found very good reproducibility BMD values of periprosthetic bone around TAR, that were comparable or even better compared to other studies that evaluated periprosthetic BMD around different prosthetic implants. DXA can be used to precisely monitor bone density around ankle prostheses, despite further long-term longitudinal studies are required to assess the clinical utility of such measurements.
INTRODUCTION: Joint prosthesis survival is associated with the quality of surrounding bone. Dual-energy X-ray absorptiometry (DXA) is capable to evaluate areal bone mineral density (BMD) around different prosthetic implants, but no studies evaluated periprosthetic bone around total ankle replacement (TAR). Our aim is to determine the precision of the DXA periprosthetic BMD around TAR. METHODOLOGY: Short-term precision was evaluated on 15 consecutive patients. Each ankle was scanned 3 times both in the posteroanterior (PA) and lateral views with a dedicated patient positioning protocol. Up to four squared regions of interest (ROIs) were placed in the periprosthetic bone around tibial and talar implants, with an additional ROI to include the calcaneal body in the lateral scan. Coefficient of variation (CV%) and least significant change were calculated according to the International Society for Clinical Densitometry. RESULTS: The lateral projection showed lower mean CV values compared to the PA projection, with an average precision error of 2.21% (lateral scan) compared to 3.34% (PA scans). Overall, the lowest precision error was found at both "global" ROIs (CV = 1.25% on PA and CV = 1.3% on lateral). The highest CV value on PA was found at the medial aspect of talar side (ROI 3; CV = 4.89%), while on the lateral scan the highest CV value was found on the posterior aspect of talar side (ROI 2; CV = 2.99%). CONCLUSIONS: We found very good reproducibility BMD values of periprosthetic bone around TAR, that were comparable or even better compared to other studies that evaluated periprosthetic BMD around different prosthetic implants. DXA can be used to precisely monitor bone density around ankle prostheses, despite further long-term longitudinal studies are required to assess the clinical utility of such measurements.