Predictive factors for intraoperative blood loss in surgery for adolescent idiopathic scoliosis.

BACKGROUND: Adolescent idiopathic scoliosis (AIS) is a common spinal deformity. Posterior spinal fusion remains an important surgical treatment for AIS. This study aims to determine the predictive factors for intraoperative blood loss in AIS surgery. METHODS: Patients who had undergone posterior spinal fusion for adolescent idiopathic scoliosis in a single university hospital were reviewed over a 7-year period. Predictive factors for intra-operative blood loss were studied by multivariate analysis to derive a regression model. Receiver operating characteristic analysis was performed to determine the cut-off values of factors contributing to significant intraoperative blood loss (≥500 ml). RESULTS: Two hundred and twelve patients were included. Intraoperative blood loss was found to be correlated with gender (rs = 0.30 (0.17-0.43)), preoperative hemoglobin level (rs = 0.20 (0.04-0.31)), preoperative Cobb angle (rs = 0.20 (0.02-0.29)), number of fused levels (rs = 0.46 (0.34-0.58)), operation duration (rs = 0.65 (0.54-0.75)), number of anchors (rs = 0.47 (0.35-0.59)), and p-value ranged from < 0.001 to < 0.05. Significant intraoperative blood loss was influenced by the male gender, operation duration greater than 257.5 min and more than 10 anchors used. CONCLUSIONS: Male gender, increased operation duration and higher number of anchors predicted higher intra-operative blood loss.

Fulcrum flexibility of the main curve predicts postoperative shoulder imbalance in selective thoracic fusion of adolescent idiopathic scoliosis.

PURPOSE: To identify preoperative predictors for postoperative shoulder imbalance (PSI) after corrective surgery of adolescent idiopathic scoliosis (AIS) and using the fulcrum-bending radiograph to assess flexibility. METHODS: A consecutive surgical cohort of AIS patients undergoing selective thoracic fusion with alternate-level pedicle screw fixation was prospectively studied. Preoperative anteroposterior, lateral and fulcrum-bending radiographs were analysed. Postoperatively, a minimum of 2 years clinical and imaging follow-up was performed of all patients. PSI was defined as a radiographic shoulder height difference of more than 20 mm. RESULTS: A total of 80 patients were included, and 14 patients (18%) were confirmed with PSI at final follow-up. The flexibility of MT curve was an independent risk factor for PSI (odds ratio (OR) = 3.3 per 10% decrease, 95% confidence interval (CI) 1.6-8.2). Twenty-seven patients had a preoperative MT flexibility of < 55% (OR = 11.5, 95% CI 2.8-46.2). Postoperative T1 tilt was significantly higher in the PSI group (p < 0.001), and a T1 tilt of more than 9° resulted in 7.2 times higher odds of developing PSI (95% CI 2.0-26.0). Fulcrum-bending correction index (FBCI) was significantly higher in the PSI group at final follow-up, and 25 patients had a final postoperative MT FBCI above 120% (OR = 8.5 (95% CI 2.3-31.0). CONCLUSIONS: A low preoperative curve flexibility is a significant predictor for PSI. The surgical strategy should consider proximal fusion in presence of low-flexibility MT curves and consider less aggressive MT curve correction. Achieving a level T1 should be a main priority during intraoperative correction and may require fusion of the PT curve. LEVEL OF EVIDENCE: III. These slides can be retrieved under Electronic Supplementary Material.

Antimicrobial prophylaxis to prevent surgical site infection in adolescent idiopathic scoliosis patients undergoing posterior spinal fusion: 2 doses versus antibiotics till drain removal.

PURPOSE: There is much variation in the choice, timing and duration of antimicrobial prophylaxis for preventing surgical site infections (SSI) but no guideline exists for scoliosis surgery. The aim of study was to compare the efficacy of two antimicrobial prophylaxis (AMP) protocols with cephazolin in preventing SSI in adolescent idiopathic scoliosis (AIS). METHODS: A retrospective comparative analysis of two post-operative AMP protocols (two postoperative doses versus continued antibiotics till drain removal) was performed. Patient characteristics, pre-operative, intra- and post-operative risk factors for infection, drain use, generic drug name and number of doses administered were recorded from 226 patients with AIS who had undergone posterior spinal fusion. Details of superficial or deep SSI and wound healing aberrations, and serious adverse events were recorded. Analysis was performed to evaluate differences in the pre-, intra- and post-operative variables between the two groups. RESULTS: 155 patients received 2 postoperative doses of AMP and 71 patients had antibiotics till drain removal. The average follow-up was 43 months. The overall rate of SSI was 1.7 % for the spine wound and 1.3 % for the iliac crest wound. 1.9 % of patients with 2 doses of AMP and 1.4 % of patients with antibiotics till drain removal had SSI. No adverse reactions attributable to cephazolin were observed. CONCLUSIONS: This is the first study on the AMP protocol in scoliosis surgery for SSI prevention. Results suggest that two doses of AMP are as effective as continued antimicrobial use until drain removal. Cephazolin appears to be effective and safe for prophylaxis.