Validation Study of the Thumb Ossification Composite Index (TOCI) in Idiopathic Scoliosis: A Stage-to-Stage Correlation with Classic Tanner-Whitehouse and Sanders Simplified Skeletal Maturity Systems.

BACKGROUND: The new simplified thumb ossification composite index (TOCI) based on ossification of the thumb epiphyses and adductor sesamoid has demonstrated simplicity, excellent reliability, and high accuracy for predicting skeletal maturity, comparable with the Sanders simplified skeletal maturity system (SSMS). It was our belief that, because the terminology of the SSMS system has been commonly used for skeletal maturity prediction in idiopathic scoliosis in publications over the past decade, the clinical applicability of the TOCI system would increase if the stages in the 2 systems were found to be interchangeable and highly correlated. METHODS: Hand radiographs of 125 premenarchal girls with newly diagnosed adolescent idiopathic scoliosis who had been followed longitudinally until skeletal maturity were all scored with use of the Tanner-Whitehouse III (TW3) system (stages E through I), the TOCI, and the SSMS. The scores for the epiphyses of the ulnar 4 digits were compared with those for the thumb and correlated with the timing of peak height velocity. Correlations were analyzed with the chi-square test and Cramer V and Somers delta correlations. RESULTS: Six hundred and forty-five hand radiographs (an average of 5 for each girl with idiopathic scoliosis) and 11,517 epiphyses were scored. The rate of concordance between TW3 stages F, G, and I for the thumb proximal phalangeal epiphysis and those for all of the epiphyses of the ulnar 4 digits were 72.5%, 72.5%, and 89.9%, respectively. The overall concordance rate (including all epiphyses) was 71.3%, with a very high Cramer V correlation and significance (p < 0.01). High interchangeability was demonstrated for the TOCI and SSMS stages, supported by a high Somers delta correlation (>0.8) with significance (p < 0.05). CONCLUSIONS: The TOCI is highly practical for clinical use, and its stages are highly interchangeable with those of the SSMS. CLINICAL RELEVANCE: The TOCI could serve as a simplified "marker" of skeletal maturity on hand radiographs and minimize the learning-curve problems associated with the SSMS in a busy clinical practice.

Use of Tranexamic Acid (TXA) on reducing blood loss during scoliosis surgery in Chinese adolescents.

BACKGROUND: Many reports had been received on the application of antifibrinolytic medications on spinal corrective surgery and the surgical outcome evaluations of its efficacy on reducing blood loss. This study aimed to assess the efficacy of tranexamic acid (TXA) in reducing operative blood loss during posterior spinal fusion for the treatment of severe adolescent idiopathic scoliosis (AIS). METHODS: A retrospective cohort study was carried out on 90 (TXA = 55, Control = 35) AIS girls undergoing posterior spinal surgery. Patients in TXA group used TXA as an antifibrinolytic agent to reduce blood loss, while control group did not. Blood loss, haemoglobin change and amount of blood transfused was estimated from intraoperative measurement by anaesthesiologists. Demographics were compared using Student's T-test or Chi-square test where appropriate. Linear regression modelling was carried out between the use of TXA and total blood loss with controlling of confounding factors. RESULTS: Mean age and mean maximum major curve were 15.2 and 73°, and 15.3 and 63° in TXA and control groups respectively. TXA group showed significantly less intra-operative blood loss than the control group from intraoperative measurement (1.8 L vs. 3.9 L, p < 0.01) and volume of cell saver blood transfused back to patients (0.6 L vs. 1.7 L, p < 0.01). TXA group also showed significantly shorter total time taken for surgery (437 min vs. 502 min, p < 0.01), and total blood loss per surgical segment level (0.1 L vs. 0.3 L, p < 0.01). Regression models showed that the use of TXA decreased total blood loss by 794.3 ml after adjusting for maximum major curve, age, number of segments fused, bone graft, clotting capability, and infusion of coagulation factors. CONCLUSIONS: Patients undergoing posterior spinal corrective surgery with the use of TXA showed much reduced total blood loss, reduced use of transfused blood, much less cell saver blood transfused back to the patient. The total blood loss was decreased by after using TXA after controlling for maximum major curve, age, surgical parameters, clotting capability, and infusion of coagulation factors.