Evaluation of Sternal Bone Healing with Computed Tomography and a Quantitative Scoring Algorithm

Abstract

Abstract:Objective: The exquisite bone detail offered by computed tomography makes it the ideal modality for evaluation of bone healing. However, few studies have investigated the normal computed tomographic appearance of the sternum after median sternotomy and, to the best of our knowledge, no computed tomographic classification of sternal healing has been proposed. Given the potential benefit of objective criteria, we propose a validated scoring classification of sternal healing using computed tomography for both clinical and investigational purposes.Methods: Computed tomography scans from 20 patients who underwent a median sternotomy were evaluated for sternal healing at either 3 or 6 months postoperatively. Five anatomic locations along the sternum were selected using defined criteria, and a 6-point quantitative scale was developed to evaluate sternal healing. Independent radiologists read and scored each of the 5 locations on the sternum. Inter-and intra-observer variability was assessed by calculating the kappa statistics to measure the reliability of the scoring algorithm.Results: Calculation of the kappa statistics indicated substantial agreement for intra-observer variability and substantial to almost perfect agreement for inter-observer variability. For intra-observer variability, the kappa statistics ranged from 0.591 to 0.802, and for inter-observer variability, the kappa statistics ranged from 0.590 to 0.969. When the two radiologists differed, the magnitude of the difference was no more than 1 or 2 points. Conclusion:This simple system of evaluating sternal healing had high inter-and intra-observer reliability. Therefore, it may be considered a valid method for assessing sternal osteosynthesis for both clinical and investigative purposes.Ultramini abstract: (49 words): Few studies have investigated the normal computed tomography appearance of the sternum after median sternotomy, and we knew of no computed tomography-based classification of sternal healing. Given the potential benefit of objective criteria, we designed and validated a scoring classification of sternal osteosynthesis for both clinical and investigational purposes.

Experimental comparison of efficiency of four different sternum closure techniques

“…However, it was observed that no significant yielding regions emerged in the obtained graphs. For this reason, instead of the yield load, the load value referred to as the critical displacement value for bone healing [14][15][16] 2 mm in different sources was called the "allowable load" and was used to compare the methods. In the second, the stiffness values of the methods were taken into account.…”

Vitamin D for prevention of sternotomy healing complications: REINFORCE-D trial

“… Sternal bone healing grade at the end of the trial evaluated by computed tomography using a 6-point scale according to Gregory S. Stacy [ 20 ], evaluation made by a certified radiologist (evaluation time point: 6th month). Total number of intensive care unit (ICU) days spent with mechanical ventilation during the original (first) heart surgery hospitalization, obtained from patient records in the hospital information system (evaluation time point: hospitalization discharge).…”

“…The optimal length of the sternum healing is, per se, the subject of debate. According to one study published in 2014, the sternum is not fully recovered after 3 nor after 6 months [ 20 ]. In this clinical trial, a 6-month period for evaluation was selected due to the high probability of capturing any sternotomy healing complications related to bones and soft tissues during the trial.…”

Sternotomy closure using rigid plate fixation: a paradigm shift from wire cerclage

“…Sternal healing was determined by a radiology core laboratory (University of Chicago, Chicago, IL) using CT and a validated method that has been described previously ( Figure 2) (9,12,17). Briefly, axial CT slices from five a priori-defined anatomic locations were selected by a core laboratory radiologist.…”

“…Briefly, axial CT slices from five a priori-defined anatomic locations were selected by a core laboratory radiologist. To preserve blinding, one core laboratory radiologist attempted to select CT slices that did not reveal which method of closure was used, then two additional radiologists independently scored each location using a 6-point scale (greater scores represent greater healing and sternal union was pre-specified and defined as a mean score of ≥3) (9,12,17). Sternal complications were defined as any adverse event related to the sternal closure and tracked through 6 months, and included deep or superficial wound infections as defined by the Society of Thoracic Surgeons (STS).…”