OBJECTIVE: To analyze the amount of blood loss at different stages of Posterior Instrumented Spinal Fusion (PSF) surgery in adolescent idiopathic scoliosis (AIS) patients.
SUMMARY OF BACKGROUND DATA: Knowing the pattern of blood loss at different surgical stages may enable the surgical team to formulate a management strategy to reduce intraoperative blood loss.
METHODS: One hundred AIS patients who underwent PSF from January 2013 to December 2014 were recruited. The operation was divided into six stages; stage 1-exposure, stage 2-screw insertion, stage 3-release, stage 4-correction, stage 5-corticotomies and bone grafting, and stage 6-closure. The duration and blood loss at each stage was documented. The following values were calculated: total blood loss, blood loss per estimated blood volume, blood loss per minute, blood loss per vertebral level fused, and blood loss per minute per vertebral level fused.
RESULTS: There were 89 females and 11 males. The mean age was 17.0 ± 5.8 years old. Majority (50.0%) were Lenke 1 curve type. The mean preoperative major Cobb angle was 64.9 ± 15.0°. The mean number of levels fused was 9.5 ± 2.3 levels. The mean operating time was 188.5 ± 53.4 minutes with a mean total blood loss 951.0 ± 454.0 mLs. The highest mean blood loss occurred at stage 2 (301.0 ± 196.7 mL), followed by stage 4 (226.8 ± 171.2 mL) and stage 5 (161.5 ± 146.6 mL). The highest mean blood loss per minute was at stage 5 (17.1 ± 18.3 mL/min), followed by stage 3 (12.0 ± 10.8 mL/min). The highest mean blood loss per vertebral levels fused was at stage 2 (31.0 ± 17.7 mL/level), followed by stage 4 (23.9 ± 18.1 mL/level) and stage 5 (16.6 ± 13.3 mL/level).
CONCLUSION: All stages were significant contributors to the total blood loss except exposure (stage 1) and closure (stage 6). Blood loss per minute and blood loss per minute per level was highest during corticotomies (stage 5), followed by release (stage 3). However, the largest amount of total blood loss occurred during screw insertion (stage 2).
LEVEL OF EVIDENCE: 2.
OBJECTIVE: To determine if surgically leveling the upper thoracic spine in patients with adolescent idiopathic scoliosis results in level shoulders postoperatively.
SUMMARY OF BACKGROUND DATA: Research has shown that preoperatively tilted proximal ribs and T1 tilt are more correlated with trapezial prominence than with clavicle angle.
METHODS: Prospectively collected Lenke 1 and 2 cases from a single center were reviewed. Clinical shoulder imbalance was measured from 2-year postoperative clinical photos. Lateral shoulder imbalance was assessed utilizing clavicle angle. Medial imbalance was assessed with trapezial angle (TA), and trapezial area ratio (TAR). First rib angle, T1 tilt, and upper thoracic curve were measured from 2-year radiographs. Angular measurements were considered level if ≤ 3° of zero. TAR was considered level if ≤ 1 standard deviation of the natural log of the ratio. Upper thoracic Cobb at 2-years was categorized as at or below the mean value (≤ 14°) versus above the mean.
RESULTS: Eighty-four patients were identified. There was no significant difference in the percentage of patients with a level clavicle angle or TAR based on first rib being level, T1 tilt being level, or upper thoracic Cobb being at/below versus above the mean (P spine does not guarantee clinically balanced shoulders or clavicles. Trapezial prominence was impacted by leveling T1 and the first rib and by minimizing the upper thoracic curve. How to achieve laterally balanced shoulders postoperatively remains unclear.
LEVEL OF EVIDENCE: 3.
OBJECTIVE: To evaluate the perioperative outcome of posterior spinal fusion in adolescent idiopathic scoliosis (AIS) patients comparing a single attending surgeon strategy (G1) versus a dual attending surgeon strategy (G2).
SUMMARY OF BACKGROUND DATA: The complication rate for surgical correction in AIS is significant. There are no prospective studies that investigate dual attending surgeon strategy for posterior spinal fusion in AIS.
METHODS: A total of 60 patients (30 patients in each arm) were recruited. The patients were comparable for age, gender, Lenke classification, major Cobb angle magnitude, and number of fusion levels. The anesthetic, surgical, and postoperative protocol was standardized. The outcome measures included the operative duration, blood loss, postoperative hemoglobin, need for transfusion, morphine usage, duration of hospital stay, intraoperative lactate levels, and pH. The timing of the operation at six critical stages of the operation was recorded.
RESULTS: The mean operative time for G2 was 173.6 ± 27.0 minutes versus 248.0 ± 49.9 minutes in G1 (P
OBJECTIVE: The aim of this study was to analyze the proximal thoracic (PT) flexibility and its compensatory ability above the "potential UIV."
SUMMARY OF BACKGROUND DATA: Shoulder and neck imbalance can be caused by overcorrection of the main thoracic (MT) curve due to inability of PT segment to compensate.
METHODS: Cervical supine side bending (CSB) radiographs of 100 Lenke 1 and 2 patients were studied. We further stratified Lenke 1 curves into Lenke 1-ve: PT side bending (PTSB) 80.0% of cases of the PT segment were unable to compensate at T3-T6. In Lenke 1+ve curves, 78.4% were unable to compensate at T6, followed by T5 (75.7%), T4 (73.0%), T3 (59.5%), T2 (27.0%), and T1 (21.6%). In Lenke 1-ve curves, 36.4% of cases were unable to compensate at T6, followed by T5 (45.5%), T4 (45.5%), T3 (30.3%), T2 (21.2%), and T1 (15.2%). A significant difference between Lenke 1-ve and Lenke 1+ve was observed from T3 to T6. The difference between Lenke 1+ve and Lenke 2 curves was significant only at T2.
CONCLUSION: The compensation ability and the flexibility of the PT segments of Lenke 1-ve and Lenke 1+ve curves were different. Lenke 1+ve curves demonstrated similar characteristics to Lenke 2 curves.
LEVEL OF EVIDENCE: 3.
OBJECTIVE: To compare the outcomes of minimal invasive surgery (MIS) and conventional open surgery for spinal metastasis patients.
SUMMARY OF BACKGROUND DATA: There is lack of knowledge on whether MIS is comparable to conventional open surgery in treating spinal metastasis.
METHODS: Patients with spinal metastasis requiring surgery from January 2008 to December 2010 in two spine centers were recruited. The demographic, preoperative, operative, perioperative and postoperative data were collected and analyzed. Thirty MIS patients were matched with 30 open surgery patients using propensity score matching technique with a match tolerance of 0.02 based on the covariate age, tumor type, Tokuhashi score, and Tomita score.
RESULTS: Both groups had significant improvements in Eastern Cooperative Oncology Group (ECOG), Karnofsky scores, visual analogue scale (VAS) for pain and neurological status postoperatively. However, the difference comparing the MIS and open surgery group was not statistically significant. MIS group had significantly longer instrumented segments (5.5 ± 3.1) compared with open group (3.8 ± 1.7). Open group had significantly longer decompressed segment (1.8 ± 0.8) than MIS group (1.0 ± 1.0). Open group had significantly more blood loss (2062.1 ± 1148.0 mL) compared with MIS group (1156.0 ± 572.3 mL). More patients in the open group (76.7%) needed blood transfusions (with higher average units of blood transfused) compared with MIS group (40.0%). Fluoroscopy time was significantly longer in MIS group (116.1 ± 63.3 s) compared with open group (69.9 ± 42.6 s). Open group required longer hospitalization (21.1 ± 10.8 days) compared with MIS group (11.0 ± 5.0 days).
CONCLUSION: This study demonstrated that MIS resulted in comparable outcome to open surgery for patients with spinal metastasis but has the advantage of less blood loss, blood transfusions, and shorter hospital stay.
LEVEL OF EVIDENCE: 3.