OBJECTIVE: The aim of this study was to compare the perioperative outcome of posterior spinal fusion (PSF) between overweight (OW) adolescent idiopathic scoliosis (AIS) patients and the healthy-weight (HW) patients using propensity score matching analysis.

SUMMARY OF BACKGROUND DATA: Obesity was found to increase postoperative surgical complications compared with the nonobese group. In scoliosis correction surgery, association of OW and perioperative risks had been explored, but most studies were retrospective in nature.

METHODS: From 374 patients, two comparable groups were matched using propensity score matching analysis with one-to-one nearest neighbor matching and a caliper of 0.2. There were 46 HW and OW patients in each group. The main outcome measures were intraoperative blood loss, use of allogeneic blood transfusion, operative time, duration of hospital stay post-surgery, total patient-controlled analgesia (PCA) morphine usage, perioperative complications, side bending flexibility (SBF), and correction rate (%).

RESULTS: The mean age was 13.3 ± 1.7 and 13.2 ± 1.7 years for HW and OW groups, respectively. The majority of the patients were Lenke 1 curves; 32.6% (HW) and 26.1% (OW) with an average Cobb angle of 69.0 ± 19.1° and 68.8 ± 18.4° for each group, respectively. The two groups were comparable. The operation time was 145.2 ± 42.2 and 154.4 ± 48.3 minutes for HW and OW groups, respectively (P > 0.05). The intraoperative blood loss was almost similar in both groups; 955.1 ± 497.7 mL (HW group) and 1011.8 ± 552.7 mL (OW group) (P > 0.05). Total PCA morphine used was higher in OW group (30.4 ± 22.7 mg) than in the HW group (16.2 ± 11.3 mg). No complication was observed in HW group, while in OW group, one patient (2.2%) developed intraoperative seizure.

CONCLUSION: OW AIS patients (≥85th percentile) had similar mean operative time, intraoperative blood loss, allogeneic transfusion rate, length of stay, and perioperative complications compared with HW AIS patients.

OBJECTIVE: The primary objective of this study was to assess the conformity of the radiological neck and shoulder balance parameters throughout a follow-up period of more than 2 years.

SUMMARY OF BACKGROUND DATA: Postoperative shoulder and neck imbalance are undesirable features among Adolescent Idiopathic Scoliosis patients who underwent Posterior Spinal Fusion. There are many clinical and radiological parameters used to assess this clinical outcome. However, we do not know whether these radiological parameters conform throughout the entire follow-up period.

METHODS: This was a retrospective study done in a single academic institution. Inclusion criteria were patients with scoliosis who underwent posterior instrumented spinal fusion with pedicle screw fixation and attended all scheduled follow-ups for at least 24 months postoperatively. Radiological shoulder parameters were measured from both preoperative antero-posterior and postoperative antero-posterior radiographs. Lateral shoulder parameters were: Radiographic Shoulder Height, Clavicle Angle (Cla-A), Clavicle-Rib Intersection Difference, and Coracoid Height Difference. Medial shoulder and neck parameters were: T1 Tilt and Cervical Axis (CA).

OBJECTIVE: To determine whether the severity of the curve magnitude in Lenke 1 and 2 Adolescent Idiopathic Scoliosis (AIS) patients affects the distance and position of the aorta from the vertebra.

SUMMARY OF BACKGROUND DATA: There were studies that looked into the position of the aorta in scoliotic patients but none of them documented the change in distance of the aorta to the vertebra in relation to the magnitude of the scoliosis.

METHODS: Patients with Lenke 1 and 2 AIS who underwent posterior spinal fusion using pedicle screw construct and had a preoperative computed tomography (CT) scan performed were recruited. The radiological parameters measured on preoperative CT scan were: Aortic-Vertebral Distance (AVD), Entry-Aortic Distance (EAD), Aortic-Vertebral angle (AVA), Pedicle Aorta angle/Aortic Alpha angle (α angle), and Aortic Beta angle (β angle).

RESULTS: Thirty-nine patients were recruited. Significant moderate to strong positive correlation was found between AVD and Cobb angle from T8 to T12 vertebrae (r = 0.360 to 0.666). The EAD was generally small in the thoracic region (T4-T10) with mean EAD of less than 30 mm. Among all apical vertebrae, the mean AVD was 5.9 ± 2.2 mm with significant moderate-strong positive correlation to Cobb angle (r = 0.580). The mean α angle was 37.7 ± 8.7° with significant weak positive correlation with Cobb angle (r = 0.325).

CONCLUSION: The larger the scoliotic curve, the aorta was located further away from the apical vertebral wall. The aorta has less risk of injury from the left lateral pedicle screw breach in larger scoliotic curve at the apical region. The distance from the pedicle screw entry point to the wall of the aorta was generally small (less than 30 mm) in the thoracic region (T4-T10).

OBJECTIVE: The aim of this study was to determine and evaluate the trajectory of surgical wound pain from day 1 to day 14 after posterior spinal fusion (PSF) surgery in patients with adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA: Information regarding how the postoperative pain improves with time offers invaluable information not only to the patients and parents but also to assist the clinician in managing postoperative pain.

METHODS: AIS patients who were planned for elective PSF surgery from September 2015 to December 2015 were prospectively recruited into this study. All patients underwent a similar pain management regimen with patient-controlled anesthesia (PCA) morphine, acetaminophen, celecoxib, and oxycodone hydrochloride.

RESULTS: A total of 40 patients (36 F:4 M) were recruited. The visual analogue score (VAS) pain score was highest at 12 hours postoperation (6.0 ± 2.3). It reduced to 3.9 ± 2.2 (day 4), 1.9 ± 1.6 (day 7), and 0.7 ± 1.1 (day 14). The total PCA usage in all patients was 12.4 ± 9.9 mg (first 12 hours), 7.1 ± 8.0 mg (12 to 24 hours), 5.6 ± 6.9 (24-36 hours), and 2.1 ± 6.1 mg (36-48 hours). The celecoxib capsules usage was reducing from 215.0 ± 152.8 mg at 24 hours to 55.0 ± 90.4 mg on day 14. The acetaminophen usage was reducing from 2275 ± 1198 mg at 24 hours to 150 ± 483 mg at day 14. Oxycodone hydrochloride capsules consumption rose to the peak of 1.4 ± 2.8 mg on day 4 before gradually reducing to none by day 13.

CONCLUSION: With an adequate postoperation pain regimen, significant pain should subside to a tolerable level by postoperative day 4 and negligible by postoperative day 7. Patient usually can be discharged on postoperative day 4 when the usage of PCA morphine was not required.

OBJECTIVE: The objective of this study was to determine whether combined total intravenous anesthesia (TIVA) technique with propofol/remifentanil is associated with less SSEP suppression when compared to combined volatile agent desflurane/remifentanil anesthesia during corrective scoliosis surgery at a comparable depth of anesthesia.

DESIGN: It is a randomized controlled trial.

SETTING: The study was conducted at the Single tertiary University Hospital during October 2014 to June 2015.

PATIENTS: Patients who required SSEP and had no neurological deficits, and were of American Society of Anesthesiologist I and II physical status, were included. Patients who had sensory or motor deficits preoperatively and significant cardiovascular and respiratory disease were excluded. A total of 72 patients were screened, and 67 patients were randomized and allocated to two groups: 34 in desflurane/remifentanil group and 33 in TIVA group. Four patients from desflurane/remifentanil group and three from TIVA group were withdrawn due to decrease in SSEP amplitude to <0.3 µV after induction of anesthesia. Thirty patients from each group were analyzed.

INTERVENTIONS: Sixty-seven patients were randomized to receive TIVA or desflurane/remifentanil anesthesia.

MAIN OUTCOME MEASURES: The measurements taken were the amplitude and latency of SSEP monitoring at five different time points during surgery: before and after the induction of anesthesia, at skin incision, at pedicle screw insertion, and at rod insertion.

RESULTS: Both anesthesia techniques, TIVA and desflurane/remifentanil, resulted in decreased amplitude and increased latencies of both cervical and cortical peaks. The desflurane/remifentanil group had a significantly greater reduction in the amplitude ( p = 0.004) and an increase in latency ( p = 0.002) of P40 compared with the TIVA group. However, there were no differences in both amplitude ( p = 0.214) and latency ( p = 0.16) in cervical SSEP between the two groups.

METHODS: The scoliosis curves were divided into eight zones. CT scans were used to assess perforations: Grade 0, Grade 1( 4 mm). Anterior perforations were classified into Grade 0, Grade 1( 6 mm). Grade 2 and 3 (except lateral grade 2 and 3 perforation over thoracic vertebrae) were considered as 'critical perforations'.

RESULTS: 1986 screws in 137 patients were analyzed. The overall perforation rate was 8.4% after exclusion of the lateral perforation. The highest medial perforation rate was at the transitional proximal thoracic (PT)/main thoracic (MT) zone (6.9%), followed by concave lumbar (6.7%) and convex main thoracic (MT) zone (6.1%). The overall critical medial perforation rate was 0.9%. 33.3% occurred at convex MT and 22.2% occurred at transitional PT/MT zone. There were 39 anterior perforations (overall perforation rate of 2.0%). 43.6% occurred at transitional PT/MT zone, whereas 23.1% occurred at concave PT zone. The overall critical anterior perforation rate was 0.6%. 5/12 (41.7%) critical perforations occurred at concave PT zone, whereas four perforations occurred at the transitional PT/MT zone. There were only two symptomatic left medial grade 2 perforations (0.1%) resulting radiculopathy, occurring at the transitional main thoracic (MT)/Lumbar (L) zone.

OBJECTIVE: To investigate whether menses affect intraoperative blood loss in female adolescent idiopathic scoliosis (AIS) patients undergoing posterior spinal fusion (PSF) surgeries.

SUMMARY OF BACKGROUND DATA: There were concerns whether patients having menses will have higher intraoperative blood loss if surgery were to be done during this period.

METHODS: This study included 372 females who were operated between May 2016 to May 2019. Fifty-five patients had menses during surgery (Group 1, G1) and 317 patients did not have menses during surgery (Group 2, G2). Propensity score matching (PSM) analysis with one-to-one, nearest neighbor matching technique and with a match tolerance of 0.001 was used. The main outcome measures were intraoperative blood loss (IBL), volume of blood salvaged, transfusion rate, preoperative hemoglobin, preoperative platelet, preoperative prothrombin time, preoperative activated partial thromboplastin time (APTT), international normalized ratio (INR), and postoperative hemoglobin. Postoperative Cobb angle and correction rate were also documented.

RESULTS: At the end of PSM analysis, 46 patients from each group were matched and balanced. The average operation duration for G1 was 140.8 ± 43.0 minutes compared with 143.1 ± 48.3 minutes in G2 (P = 0.806). The intraoperative blood loss for G1 was 904.3 ± 496.3 mL and for G2 was 907.9 ± 482.8 mL (P = 0.972). There was no significant difference in terms of normalized blood loss (NBL), volume of blood salvaged during surgery, preoperative hemoglobin, postoperative hemoglobin, hemoglobin drift, estimated blood volume (EBV), IBL per EBV and IBL per level fused (P > 0.05). No postoperative complications were encountered in both groups. On average, the postoperative hospital stay was 3.5 ± 0.8 days for both groups (P = 0.143).

CONCLUSION: Performing corrective surgery during the menstrual phase in female AIS patients is safe without risk of increased blood loss.

OBJECTIVE: To evaluate the perioperative outcome of dual attending surgeon strategy for severe adolescent idiopathic scoliosis (AIS) patients with Cobb angle more than or equal to 90°.

SUMMARY OF BACKGROUND DATA: The overall complication rate for AIS remains significant and is higher in severe scoliosis. Various operative strategies had been reported for severe scoliosis. However the role of dual attending surgeon strategy in improving the perioperative outcome in severe scoliosis has not been investigated.

METHODS: The patients were stratified into two groups, Cobb angles 90° to 100° (Group 1) and more than 100° (Group 2). Demographic, intraoperative, preoperative, and postoperative day 2 data were collected. The main outcome measures were intraoperative blood loss, use of allogeneic blood transfusion, operative time, duration of hospital stay postsurgery, and documentation of any perioperative complications.

RESULTS: Eighty-five patients were recruited. The mean age for the whole cohort was 16.2 ± 5.2 years old. The mean age of Group 1 was 16.7 ± 5.7 and Group 2 was 15.6 ± 4.8 years old. The majority of the patients in both groups were Lenke 2 curves with the average Cobb angle of 93.9 ± 3.0° in Group 1 and 114.2 ± 10.2° in Group 2. The average operative time was 198.5 ± 47.5 minutes with an average blood loss of 1699.5 ± 939.3 mL. The allogeneic blood transfusion rate was 17.6%. The average length of stay postoperation was 71.6 ± 22.5 hours. When comparing the patients between Group 1 and Group 2, the operating time, total blood loss, allogeneic transfusion rate showed significant intergroup differences. Five complications were documented (one intraoperative seizure, one massive blood loss, one intraoperative loss of somatosensory evoked potential (SSEP) signal, and two superficial wound breakdown).

CONCLUSION: Dual attending surgeon strategy in severe AIS more than or equal to 90° demonstrated an average operative time of 199 minutes, intraoperative blood loss of 1.7 L, postoperative hospital stay of 71.6 hours, and a complication rate of 5.9% (5/85 patients). Curves with Cobb angle more than 100° lead to longer operating time, greater blood loss, and allogeneic transfusion rate.

OBJECTIVE: To compare the perioperative outcome between after-hours and daytime surgery carried out by a dedicated spinal deformity team for severe Idiopathic Scoliosis (IS) patients with Cobb angle ≥ 90°.

SUMMARY OF BACKGROUND DATA: There were concerns that after-hours corrective surgeries in severe IS have higher morbidity compared to daytime surgeries.

METHODS: Seventy-one severe IS patients who underwent single-staged Posterior Spinal Fusion (PSF) were included. Surgeries performed between 08:00H and 16:59H were classified as "daytime" group and surgeries performed between 17:00H and 06:00H were classified as "after-hours" group. Perioperative outcome parameters were average operation start time and end time, operation duration, intraoperative blood loss, intraoperative hemodynamic parameters, preoperative and postoperative hemoglobin, blood transfusion rate, total patient-controlled anesthesia (PCA) morphine usage, length of postoperative hospitalization, and complications. Radiological variables assessed were preoperative and postoperative Cobb angle, side bending flexibility, number of fusion levels, number of screws used, Correction Rate, and Side Bending Correction Index.

RESULTS: Thirty patients were operated during daytime and 41 patients were operated after-hours. The mean age was 16.1 ± 5.8 years old. The mean operation start time for daytime group was 11:31 ± 2:45H versus 19:10 ± 1:24H for after-hours group. There were no significant differences between both groups in the operation duration, intraoperative blood loss, intraoperative hemodynamic parameters, postoperative hemoglobin, hemoglobin drift, transfusion rate, length of postoperative hospitalization, postoperative Cobb angle, Correction Rate, and Side Bending Correction Index. There were four complications (1 SSEP loss, 1 massive blood loss, and 2 superficial wound infections) with no difference between daytime and after-hours group.

CONCLUSION: After-hours elective spine deformity corrective surgeries in healthy ambulatory patients with severe IS performed by a dedicated spinal deformity team using dual attending surgeon strategy were as safe as those performed during daytime.