Sternal transplant using cadaveric allograft: quantitative and qualitative assessment of bone healing by computed
Chiara Giraudo1, Francesca Nistri1, Pia Ferrigno2
1Radiology Institute, Department of Medicine - DIMED, University of Padova, Padova, Italy.
Background:
Sternal transplant using cadaveric allograft (STCA) is a complex and rarely performed surgical procedure usually applied for massive bone tissue loss, sternotomy complications, or neoplastic resections. Although radiological imaging and especially computed tomography (CT) is routinely applied for the post-surgical assessment, up to now, a standardized approach evaluating the outcome of STCAs is missing. Therefore, aim of this study was to qualitatively and quantitatively evaluate, by CT, bone healing after STCA.
Methods:
The first and the last available postsurgical CT of patients who underwent STCA in two tertiary centers between 2009 and 2017 were collected. Standardized regions of interest were applied on the cancellous bone along the transplanted sternum, and, as reference, on the fourth thoracic vertebra, at both time points, collecting the density values. The areas nearby the fixation devices were assessed by a four-points qualitative score. To evaluate the mineralization, the analysis of the variance (ANOVA) with post-hoc Bonferroni correction was applied for the quantitative measurements while the Wilcoxon test was used for the qualitative score (P<0.05). To evaluate the intra-rater reliability of the qualitative and the quantitative analyses, the same rater repeated the measurements after two months and the Cohen's kappa (k) and the intraclass correlation coefficient (ICC) were computed.
Results:
Fourteen patients (11 females, 61±12.8 years) were examined. The first control CTs were performed 32±40.26 days after the STCA and the last CT were acquired after 729±745 days. The quantitative and the qualitative score significantly increased between the two intervals (P<0.05, each). The density of the transplanted sternum was lower than that of the vertebral reference at the first CT (P=0.006) while no differences occurred at the last control (P=0.361). The assessments showed high intra-rater reliability and agreement (ICC ≥0.890, k≥0.906).
Conclusions:
The hereby-proposed qualitative and quantitative methods demonstrated to be good tools for assessing bone healing after STCA.
