OBJECTIVE: To evaluate the surgical learning curve of a dual attending surgeon strategy in IS patients.

STUDY DESIGN: Retrospective study.

PATIENT SAMPLE: 415 IS patients (Cobb angle <90°) who underwent PSF using a dual attending surgeon strategy OUTCOME MEASURES: Primary outcomes included operative time, total blood loss, allogenic blood transfusion requirement, length of hospital stay and perioperative complication rate.

METHODS: Regression analysis using Locally Weighted Scatterplot Smoothing (LOWESS) method was applied to create the best-fit-curve between case number versus operative time and total blood loss in identifying cut-off points for the learning curve.

PURPOSE: To evaluate the accuracy, safety, and diagnostic outcome of fluoroscopic guided and CT transpedicular biopsy techniques.

STUDY DESIGN: Prospective randomized trial.

PATIENT SAMPLE: Sixty consecutive patients with clinical symptoms and radiological features suggestive of spinal infection or malignancy were recruited and randomized into fluoroscopic or CT guided spinal biopsy groups. Both groups were similar in terms of patient demographics, distribution of spinal infections and malignancy cases, and the level of biopsies.

OUTCOME MEASURES: The primary outcome measure was diagnostic accuracy of both methods, determined based on true positive, true negative, false positive, and false negative biopsy findings. Secondary outcome measures included radiation exposure to patients and doctors, complications, and postbiopsy pain score.

METHODS: A transpedicular approach was performed with an 8G core biopsy needle. Specimens were sent for histopathological and microbiological examinations. Diagnosis was made based on biopsy results, clinical criteria and monitoring of disease progression during a 6-month follow up duration. Clinical criteria included presence of risk factors, level of inflammatory markers and magnetic resonance imaging findings. Radiation exposure to patients and doctors was measured with dosimeters.

RESULTS: There was no significant difference between the diagnostic accuracy of fluoroscopic and CT guided spinal biopsy (p=0.67) or between the diagnostic accuracy of spinal infection and spinal tumor in both groups (p=0.402 for fluoroscopy group and p=0.223 for CT group). Radiation exposure to patients was approximately 26 times higher in the CT group. Radiation exposure to doctors in the CT group was approximately 2 times higher compared to the fluoroscopic group if a lead shield was not used. Lead shields significantly reduced radiation exposure to doctors anywhere from 2 to 8 times. No complications were observed for either group and the differences in postbiopsy pain scores were not significant.

OBJECTIVE: This study aimed to assess the radiological and clinical outcome of patients with Lenke 1C and 2C curves treated with STF.

STUDY DESIGN: This is a retrospective study.

PATIENT SAMPLE: A total of 44 patients comprised the study sample.

METHODS: Forty-four patients with Lenke 1C and 2C curves with adolescent idiopathic scoliosis who underwent STF were reviewed. Radiological parameters and Scoliosis Research Society (SRS)-22r scores were assessed preoperatively, postoperatively, and on final follow-up. The incidence of coronal decompensation, lumbar decompensation, and adding-on phenomenon were reported.

OBJECTIVE: This study analyzed the flexibility of the unfused thoracic segments above the "potential upper instrumented vertebrae (UIV)" (T1-T12) and its compensatory ability in Lenke 5 and 6 curves using supine side bending (SSB) radiographs.

STUDY DESIGN: A retrospective study was used.

PATIENT SAMPLE: This study comprised 100 patients.

OUTCOME MEASURES: The ability of the unfused thoracic segments above the potential UIV, that is, T1-T12, to compensate in Lenke 5 and 6 curves was determined. We also analyzed postoperative radiological outcome of this cohort of patients with a minimum follow-up of 12 months.

METHODS: Right and left SSB were obtained. Right side bending (RSB) and left side bending (LSB) angles were measured from T1 to T12. Compensatory ability of thoracic segments was defined as the ability to return to neutral (center sacral vertical line [CSVL]) with the assumption of maximal correction of lumbar curve with a horizontal UIV. The Lenke 5 curves were classified as follows: (1) Lenke 5-ve (mobile): main thoracic Cobb angle <15° and (2) Lenke 5+ve (stiff): main thoracic Cobb angle 15.0°-24.9°. This study was self-funded with no conflict of interest.

RESULTS: There were 43 Lenke 5-ve, 31 Lenke 5+ve, and 26 Lenke 6 curves analyzed. For Lenke 5-ve, >70% of thoracic segments were able to compensate when UIV were at T1-T8 and T12 and >50% at T9-T11. For Lenke 5+ve, >70% at T1-T6 and T12, 61.3% at T7, 38.7% at T8, 3.2% at T9, 6.5% at T10, and 22.6% at T11 were able to compensate. For Lenke 6 curve, >70% at T1-T6, 69.2% at T7, 19.2% at T8, 7.7% at T9, 0% at T10, 3.8% at T11, and 34.6% at T12 were able to compensate. There was a significant difference between Lenke 5-ve versus Lenke 5+ve and Lenke 5-ve versus Lenke 6 from T8 to T11. There were no significance differences between Lenke 5+ve and Lenke 6 curves from T1 to T11.

PURPOSE: To investigate the prevalence and distribution of narrow dysplastic and fully corticalized pedicles in Asian AIS patients with major main thoracic curves.

DESIGN: Retrospective study.

PATIENT SAMPLE: A total of 6,494 pedicles in 191 patients were measured and evaluated.

OUTCOME MEASURES: The primary outcomes measures were the pedicle width measurements (total transverse pedicle width, transverse cancellous width, total transverse cortical width) and classification of pedicles. Demographic data (age, gender, height, weight, body mass index), proximal thoracic Cobb angle, main thoracic Cobb angle and lumbar Cobb angle were also obtained.

METHODS: AIS patients with major (largest Cobb angle) main thoracic curves and had computed tomography (CT) scans prior to corrective spine surgery were reviewed. The pedicles were classified as Grade A: cancellous channel >4 mm; Grade B: cancellous channel 2 to 4 mm; Grade C: cancellous channel <2 mm or corticalized pedicle >4 mm; Grade D: corticalized pedicle ≤4 mm. Grades B, C, and D were dysplastic pedicles while grades C and D were narrow dysplastic pedicles.

RESULTS: The prevalence of dysplastic pedicles (grades B, C, and D) was 61.7%. There were 22.6% narrow dysplastic pedicles (grades C and D) and 4.1% fully corticalized pedicles (grade D). In the thoracolumbar region, there was a sharp transition from larger and less dysplastic pedicles at T11 and T12 to narrower and more dysplastic pedicles at L1 and L2 (narrow dysplastic pedicles at T11: 3.1%, T12: 3.1%, L1: 39.8% and L2: 23.6%). Higher prevalences of narrow dysplastic pedicles were located at right T3 to T5 (71.2%-83.7%) and left T7-T9 (51.3%-61.2%). Higher prevalences of fully corticalized pedicles were located at right T3 to T5 (20.9%-34.0%) and left T7 to T8 (11.0%-12.0%). These were the concave pedicles of proximal thoracic and main thoracic curves, respectively.

PURPOSE: This study aims to identify the distribution and variation of medial and lateral pedicle wall widths throughout the different vertebral levels of the scoliotic spine and its differences according to age, gender, body mass index (BMI), maturity, curve types and curve severity in adolescent idiopathic scoliotic (AIS) patients with major thoracic curves.

STUDY DESIGN: Retrospective Study PATIENT SAMPLE: A total of 6230 pedicles (right: 3064, left: 3166) from 191 patients were included in this study with 264 (right: 183, left: 81) fully corticalized pedicles excluded from analysis.

OUTCOME MEASURES: Demographic data were age, gender, height, weight, BMI, Risser grade, Lenke curve types and Cobb angles. Main outcome measures were medial and lateral pedicle wall widths. Associations between pedicle wall widths and demographic data were calculated.

METHODS: This was a sub-analytical retrospective study done on the same patient population as the previously published study on pedicle grading. The data was obtained from the main computed tomography (CT) scan pedicle study dataset. Medial and lateral pedicle wall widths were measured in the axial slices of CT scans from T1 to L5 vertebrae.

RESULTS: A total of 6230 pedicles (right: 3064, left: 3166) from 191 patients were included in this study with 264 (right: 183, left: 81) fully corticalized pedicles excluded from analysis. Right-sided medial pedicle wall widths were narrower from T4-T10 (0.75 ± 0.23 mm) compared to T1-T3 (0.89 ± 0.28 mm) and T11-L5 (0.92 ± 0.30 mm). Left-sided medial pedicle wall widths were narrower from T4 to T7 (0.76 ± 0.24 mm) compared to T1-T3 (0.88 ± 0.26 mm) and T8-L5 (0.90 ± 0.27 mm). Medial cortical wall widths were significantly thicker compared to lateral cortical wall widths for all vertebras from T1 to L5 (right medial 0.85 ± 0.28 mm vs lateral 0.64 ± 0.26 mm (p<0.001), left medial 0.86 ± 0.26 mm vs lateral 0.64 ± 0.26 mm (p<0.001)). The left medial pedicle wall widths were marginally significantly (p<0.001) thicker than right side (right medial 0.85 ± 0.28 mm vs left 0.86 ± 0.26 mm). Then main notable significant differences were located at the periapical region of the thoracic curve between T7 to T10 with left concave medial pedicle width being thicker than right convex medial pedicle width. The thinnest medial pedicle walls were located at right concave T7 (0.73 ± 0.24 mm) and T8 (0.73 ± 0.23 mm). We generally found no significant associations between the medial and lateral pedicle wall widths with age, gender, BMI, Risser grade, Cobb angle and curve types.

PURPOSE: To investigate the use of supine and side bending (SB) radiographs in predicting postoperative curve correction in AdIS patients who underwent PSF.

STUDY DESIGN: Retrospective study.

PATIENT SAMPLE: 93 AdIS patients who underwent PSF between 2022 and 2023 were included.

OUTCOME MEASURES: Demographic data were age, gender, height, weight, body mass index (BMI), Risser grade, Lenke curve types and Cobb angles. Main outcome measures were preoperative and immediate postoperative Cobb angle (proximal thoracic [PT], main thoracic [MT] and thoracolumbar/lumbar [TL/L] curves), Supine Cobb angle and Flexibility rate (PT, MT and TL/L), and Correction rate (PT, MT and TL/L).

METHODS: Correlation study was performed between Supine Cobb angle vs. postoperative Cobb angle for PT, MT and TL/L curves. A predictive formula was derived from the correlation plots.