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.
CONCLUSIONS: The compensatory ability of the unfused thoracic segment of Lenke 5+ve curves was different from the Lenke 5-ve curves, and it demonstrated characteristics similar to the Lenke 6 curves.
METHODS: Computed tomography scans from 74 patients were retrospectively evaluated between January 2008 and December 2012. Pedicle perforations were classified by two types of grading systems. For medial, lateral, superior and inferior perforations: grade 0 - no violation; grade 1 - <2 mm; grade 2 - 2-4 mm and grade 3 - >4 mm. For anterior perforations: grade 0 - no violation; grade 1 - <4 mm; grade 2 - 4-6 mm and grade 3 - >6 mm.
RESULTS: There were 35 (47.3%) male and 39 (52.7%) female patients with a total 260 thoracic pedicle screws (T1-T6) analysed. There were 32 screw perforations which account to a perforation rate of 12.3% (11.2% grade 1, 0.7% grade 2 and 0.4% grade 3). None led to pedicle screw-related complications. The perforation rate was highest at T1 (33.3%, all grade 1 perforations), followed by T6 (14.5%) and T4 (14.0%).
CONCLUSION: Fluoroscopic guided percutaneous pedicle screws of the upper thoracic spine (T1-T6) are technically more demanding and carry potential risks of serious complications. Extra precautions need to be taken when fluoroscopic guided percutaneous pedicle screws are placed at T1 and T2 levels, due to high medial pedicular angulation and obstruction of lateral fluoroscopic images by the shoulder girdle and at T4-T6 levels, due to smaller pedicular width.
PURPOSE: To study the various surgical practices of different surgeons in the Asia-Pacific region.
OVERVIEW OF LITERATURE: Given the diversity among Asia-Pacific surgeons, there is no clear consensus on the preferred management strategies for cervical myelopathy. In particular, the role of prophylactic decompression for silent cervical spinal stenosis is under constant debate and should be addressed.
METHODS: Surgeons from the Asia-Pacific Spine Society participated in an online questionnaire comprising 50 questions. Data on clinical diagnosis, investigations and outcome measures, approach to asymptomatic and silent cervical spinal stenosis, guidelines for surgical approach, and postoperative immobilization were recorded. All parameters were analyzed by the Mantel-Haenszel test.
RESULTS: A total of 79 surgeons from 16 countries participated. Most surgeons used gait disturbance (60.5%) and dyskinetic hand movement (46.1%) for diagnosis. Up to 5.2% of surgeons would operate on asymptomatic spinal stenosis, and 18.2% would operate on silent spinal stenosis. Among those who would not operate, most (57.1%) advised patients on avoidance behavior and up to 9.5% prescribed neck collars. For ossification of the posterior longitudinal ligament (OPLL), anterior removal was most commonly performed for one-level disease (p<0.001), whereas laminoplasty was most commonly performed for two- to four-level disease (p=0.036). More surgeons considered laminectomy and fusion for multilevel OPLL. Most surgeons generally preferred to use a rigid neck collar for 6 weeks postoperatively (p<0.001).
CONCLUSIONS: The pooled recommendations include prophylactic or early decompression surgery for patients with silent cervical spinal stenosis, particularly OPLL. Anterior decompression is primarily suggested for one- or two-level disease, whereas laminoplasty is preferred for multilevel disease.
PURPOSE: To compare patients' and parents' perceptions of physical attributes (PAs) of adolescent idiopathic scoliosis (AIS) patients and to report any correlations between their perceptions and Scoliosis Research Society-22r (SRS-22r) scores.
OVERVIEW OF LITERATURE: Few studies have looked into the differences between patients' and parents' perceptions of their appearance.
METHODS: AIS patient-parent pairs (n=170) were recruited. The patients' and parents' perceptions of six PAs were evaluated: waist asymmetry (WA), rib hump (RH), shoulder asymmetry (SA), neck tilt, breast asymmetry (BrA), and chest prominence. These PAs were ranked, and an aggregate PA (Agg-PA) score was derived from a score assigned to the attribute (6 for the most important PA and 1 for the least important). The patients also completed the SRS-22r questionnaire.
RESULTS: Ninety-nine patients (58.2%) and 71 patients (41.8%) had thoracic and lumbar major curves, respectively. WA was ranked first by 54 patients (31.8%) and 50 parents (29.4%), whereas RH was ranked first by 50 patients (29.4%) and 38 parents (22.4%). The overall Agg-PA scores were similar for patients and parents (p>0.05). However, for thoracic major curves (TMCs) >40°, a significant difference was noted between the Agg-PA scores of patients and parents for SA (3.5±1.6 vs. 4.2±1.6, p=0.041) and BrA (3.0±1.6 vs. 2.2±1.3, p=0.006). For TMCs <40°, a significant difference was found between the Agg-PA scores of patients and parents for WA (3.7±1.6 vs. 4.4±1.5, p=0.050). BrA was negatively correlated with total SRS-22r score.
CONCLUSIONS: There were no significant differences between patients and parents in their ranking of the most important PAs. For TMCs >40°, there were significant differences in the Agg-PA for SA and BrA. Pa¬tients were more concerned about BrA and parents were more concerned about SA. Patients' perception of the six PAs had weak correlation with SRS-22r scores.
METHODS: All surgeries were performed by minimally invasive technique with either percutaneous monoaxial or percutaneous polyaxial screws inserted at adjacent fracture levels perpendicular to both superior end plates. Fracture reduction is achieved with adequate rod contouring and distraction maneuver. Radiological parameters were measured during preoperation, postoperation, and follow-up.
RESULTS: A total of 21 patients were included. Eleven patients were performed with monoaxial pedicle screws and 10 patients performed with polyaxial pedicle screws. Based on AO thoracolumbar classification system, 10 patients in the monoaxial group had A3 fracture type and 1 had A4. In the polyaxial group, six patients had A3 and four patients had A4. Total correction of anterior vertebral height (AVH) ratio was 0.30 ± 0.10 and 0.08 ± 0.07 in monoaxial and polyaxial groups, respectively (p < 0.001). Total correction of posterior vertebral height (PVH) ratio was 0.11 ± 0.05 and 0.02 ± 0.02 in monoaxial and polyaxial groups, respectively (p < 0.001). Monoaxial group achieved more correction of 13° (62.6%) in local kyphotic angle compared to 8.2° (48.0%) in polyaxial group. Similarly, in regional kyphotic angle, 16.5° (103.1%) in the monoaxial group and 8.1° (76.4%) in the polyaxial group were achieved.
CONCLUSIONS: Monoaxial percutaneous pedicle screws inserted at adjacent fracture levels provided significantly better fracture reduction compared to polyaxial screws in thoracolumbar fractures.
METHODS: In total, 311 patients underwent erect whole spine anteroposterior, lateral and lower limb axis films. Radiographic measurements included Transilium Pelvic Height Difference (TPHD; mm), Hip Abduction-Adduction angle (H/Abd-Add; °), Lower limb Length Discrepancy (LLD; mm), and Pelvic Hypoplasia (PH angle; °). The incidence and severity of pelvic obliquity were stratified to Lenke curve subtypes in 311 patients. The causes of pelvic obliquity were analyzed in 57 patients with TPHD ≥10 mm.
RESULTS: The mean Cobb angle was 64.0 ± 17.2°. Sixty-nine patients had a TPHD of 0 mm (22.2%). The TPHD was <5 mm in 134 (43.0%) patients, 5-9 mm in 104 (33.4%) patients, 10-14 mm in 52 (16.7%) patients, 15-19 mm in 19 (6.1%) patients, and ≥20 mm in only 2 (0.6%) patients. There was a significant difference between the Lenke curve types in terms of TPHD (p = 0.002). L6 curve types had the highest TPHD of 9.0 ± 6.3 mm followed by L5 curves, which had a TPHD of 7.1 ± 4.8 mm. In all, 44.2% of L1 curves and 50.0% of L2 curves had positive TPHD compared to 66.7% of L5 curves and 74.1% of L6 curves which had negative TPHD. 33.3% and 24.6% of pelvic obliquity were attributed to PH and LLD, respectively, whereas 10.5% of cases were attributed to H/Abd-Add positioning.
CONCLUSIONS: 76.4% of AIS cases had pelvic obliquity <10 mm; 44.2% of L1 curves and 50.0% of L2 curves had a lower right hemipelvis compared to 66.7% of L5 curves and 74.1% of L6 curves, which had a higher right hemipelvis. Among patients with pelvic obliquity ≥10 mm, 33.3% were attributed to PH, whereas 24.6% were attributed to LLD.
METHODS: Patients included had the diagnosis of significant back pain caused by osteoporotic vertebral compression fracture secondary to trivial injury. All the patients underwent routine preoperative sitting lateral spine radiograph, supine stress lateral spine radiograph, and supine anteroposterior spine radiograph. The radiological parameters recorded were anterior vertebral height (AVH), middle vertebral height (MVH), posterior vertebral height (PVH), MVH level below, wedge endplate angle (WEPA), and regional kyphotic angle (RKA). The supine stress versus sitting difference (SSD) for all the above parameters were calculated.
RESULTS: A total of 28 patients (4 males; 24 females) with the mean age of 75.6 ± 7.7 years were recruited into this study. The mean cement volume injected was 5.5 ± 1.8 ml. There was no difference between supine stress and postoperative radiographs for AVH ( p = 0.507), PVH ( p = 0.913) and WEPA ( p = 0.379). The MVH ( p = 0.026) and RKA ( p = 0.005) were significantly less in the supine stress radiographs compared to postoperative radiographs. There was significant correlation ( p < 0.05) between supine stress and postoperative AVH, MVH, PVH, WEPA, and RKA. The SSD for AVH, PVH, WEPA, and RKA did not have significant correlation with the cement volume ( p > 0.05). Only the SSD-MVH had significant correlation with cement volume, but the correlation was weak ( r = 0.39, p = 0.04).
CONCLUSIONS: Dynamic mobility stress radiographs can predict the postoperative vertebral height restoration and kyphosis correction after vertebroplasty for thoracolumbar osteoporotic fracture with intravertebral clefts. However, it did not reliably predict the amount of cement volume injected as it was affected by other factors.
Materials and methods: We reviewed four patients with neurofibromatosis with severe PT spinal deformity. Case 1, a 16-year-old male presented with severe PT kyphoscoliosis (scoliosis: 89°, kyphosis: 124°) and thoracic myelopathy. Case 2 was a 14-year-old, skeletally immature male who presented with a PT lordoscoliosis (scoliosis: 85°). Case 3, a 13-year-old male, presented with severe PT kyphoscoliosis (scoliosis: 100°, kyphosis: 95°). Case 4, a 35-year-old gentleman, presented with severe PT kyphoscoliosis (scoliosis: 113°, kyphosis: 103°) and thoracic myelopathy. All patients underwent pre-operative halo-pelvic traction. After a period of traction, all patients underwent posterior spinal fusion (PSF) with autologous bone grafts (local and fibula bone grafts) and recombinant human bone morphogenetic protein-2 (rhBMP-2).
Results: Both patients with thoracic myelopathy regained near normal neurological status after halo-pelvic traction. Following traction, the scoliosis correction rate (CR) ranged from 18.0% to 38.9%, while the kyphosis CR ranged from 14.6% to 37.1%. Following PSF, the scoliosis CR ranged from 24.0% to 58.8%, while the kyphosis CR ranged from 29.1% to 47.4%. The total distraction ranged from 50-70mm. Duration of distraction ranged from 26-95 days. The most common complication encountered during halo-pelvic traction was pin-related e.g. pin tract infection, pin loosening and migration, osteomyelitis, and halo-pelvic strut breakage. No patients had cranial nerve palsies or neurological worsening.
Conclusion: Pre-operative correction of severe PT spinal deformities could be performed safely and effectively with the halo-pelvic device prior to definitive surgery.
PURPOSE: To evaluate the relationship between shoulder/ neck imbalance with distal adding-on phenomenon and to identify other risk factors in Lenke 1 and 2 (non-AR curves) adolescent idiopathic scoliosis (AIS) patients.
METHODS: 100 Lenke 1 and 2 AIS patients with lowest instrumented vertebra (LIV) cephalad to or at L1 were recruited. Medial shoulder/ neck balance was represented by T1-tilt and cervical axis (CA). Lateral shoulder balance was represented by clavicle angle (Cla-A) and radiographic shoulder height (RSH). Distal adding-on phenomenon was diagnosed when there was disc wedging below LIV of >5o at final follow-up. Predictive factors and odds ratio were derived using univariate and multivariate logistic regression analysis.
RESULTS: Mean age of this cohort was 15.9 ± 4.4 years. Mean follow-up duration was 30.9 ± 9.6 months. Distal adding-on phenomenon occurred in 19 patients (19.0%). Only Risser grade, preoperative CA and final follow-up lumbar Cobb angle were the independent factors. A positive preoperative CA deviation increased the odds of distal adding-on by 5.4 times (95% CI 1.34-21.51, P = 0.018). The mean immediate postoperative T1-tilt, CA, RSH and Cla-A were comparable between the group with distal adding-on and the group without.
CONCLUSION: Distal adding-on phenomenon occurred in 19.0% of patients. Preoperative "Cervical Axis" was an important factor and it increased the risk of distal adding-on by 5.4 times. Other significant predictive factors were Risser grade and lumbar Cobb angle at final follow-up. Immediate postoperative shoulder or neck imbalance was not a significant factor for postoperative distal adding-on phenomenon.
OBJECTIVE: To investigate the perioperative outcomes comparing adolescent idiopathic scoliosis (AIS) and adult idiopathic scoliosis (AdIS) patients following posterior spinal fusion (PSF).
METHODS: 425 female AIS and AdIS patients who were operated (between January 2015 to March 2020) using a dual attending surgeon strategy were stratified into G1 (AIS aged 10-16 years old) and G2 (AdIS > 20 years old). PSM analysis with one-to-one, nearest neighbor matching technique with match tolerance of 0.001 was used to matched 357 AIS patients to 68 AdIS patients. Operation duration, intraoperative blood loss (IBL), blood loss percentage, hemoglobin drift, blood salvaged, postoperative wound length, allogenic blood transfusion requirement, postoperative hospital stay, postoperative Cobb, correction rate and postoperative complications were documented and reported.
RESULTS: Following PSM, G1 and G2 each had 50 patients with comparable and balanced covariates. As anticipated, G2 patients were heavier, taller and had higher body mass index compared to G1 patients (P < 0.05). We could not find any significant differences in the perioperative outcome comparing this 2 groups. AIS and AdIS patients had similar operation duration (125.9 ± 27.2 min vs 127.3 ± 37.8 min), IBL (749.8 ± 315.7 ml vs 723.8 ± 342.1 ml) and length of hospital stay (3.3 ± 0.4 days vs 3.5 ± 0.8 days) (P > 0.05). Hemoglobin drift and amount of blood salvaged were comparable (P > 0.05). G2 had stiffer curves. There was a trend toward a lower correction rate in G2 in the immediate postoperative period, however it did not reach statistical significance (61.8 ± 11.2% vs. 66.3 ± 11.6%, P = 0.051). No patients required blood transfusion and none had any postoperative complications.
CONCLUSION: Adolescent and adult female scoliosis patients had comparable perioperative outcome following PSF surgery that was carried out using a dual attending surgeon strategy.
OBJECTIVE: The objective of this study is to determine the efficacy of high-dose versus low-dose tranexamic acid (TXA) in adolescent idiopathic scoliosis (AIS) corrective surgery.
SUMMARY OF BACKGROUND DATA: Corrective surgery for AIS is associated with significant blood loss. Evidence on the optimum TXA dose to reduce bleeding in pediatric population is scarce.
METHODS: A total of 166 AIS patients aged between 10 and 21 years, of American Society of Anesthesiologists (ASA) physical status I and II, preoperative hemoglobin >10 g/dL, platelet count >150,000 cells/L and Cobb angle of >45° scheduled for elective single-stage posterior spinal fusion (PSF) surgery by two attending surgeons were included between March 2017 and November 2018. Patients were randomized into Group A (High Dose, 30 mg/kg TXA loading dose followed by 10 mg/kg/h infusion) and Group B (Low Dose, 10 mg/kg TXA loading dose followed by 1 mg/kg/h infusion). The primary outcome was total surgical blood loss between both groups. Secondary outcomes were transfusion requirement, perioperative changes in hemoglobin and coagulation profiles, adverse events, and factors that influence total blood loss.
RESULTS: The mean total surgical blood loss between the two groups was not significant (Group A: 928.8 ± 406.1 mL [range: 348-1857 mL]; Group B: 918.1 ± 406.2 mL [range: 271-2000 mL], P = 0.865). The median duration of surgery was 120 minutes. One patient in each group received allogenic blood transfusion during the perioperative period. There were no significant changes in hemoglobin and coagulation profile at pre-operation, post-operation 0 hour and 48 hours. Sex, number of vertebral levels fused, and duration of surgery were independently associated with total surgical blood loss. No adverse events were observed perioperatively.
CONCLUSION: Low-dose TXA was as efficacious as high-dose TXA in reducing blood loss and allogenic blood transfusion for AIS patients undergoing PSF surgery.Level of Evidence: 1.
SUMMARY OF BACKGROUND DATA: Prolonged operation duration in adolescent idiopathic scoliosis (AIS) surgery was associated with increased perioperative complications. However, the factors affecting operation duration in AIS surgery were unknown.
OBJECTIVE: The aim of the study was to investigate the factors affecting operation duration in posterior spinal fusion (PSF) surgery using a dual attending surgeon strategy among Lenke 1 and 2 AIS patients.
METHODS: In all, 260 AIS patients with Lenke 1 and 2 curves who underwent PSF were retrospectively reviewed. Preoperative and intraoperative factors affecting operation duration such as age, sex, height, weight, body mass index, Risser grade, Lenke subtypes, number of fusion level, number of screws, screw density, wound length, upper and lowest instrumented vertebrae level, preoperative Cobb angle, and flexibility of the major curve were assessed using univariate and multivariate linear regression analyses. Independent factors were determined when P-value <0.05.
RESULTS: The mean operation duration was 122.2±28.6 minutes. Significant independent factors affecting operation duration in PSF among Lenke 1 and 2 AIS patients were Lenke 2 subtypes (β=8.86, P=0.008), number of screws (β=7.01, P<0.001), wound length (β=1.14, P=0.009), and flexibility of the major curve (β=-0.25, P=0.005). The overall model fit was R2=0.525. Operation duration can be predicted using the formula: (8.86×Lenke subtypes)+(7.01×number of screws)+(1.14×wound length)-(0.25×flexibility)-0.54, where Lenke 2=1 and Lenke 1=0.
CONCLUSION: The factors affecting operation duration in PSF among Lenke 1 and 2 AIS patients were Lenke 2 curves, number of screws, wound length, and curve flexibility. The knowledge of these factors enables the spinal deformity surgeons to plan and estimate the operation duration before AIS surgery.
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.
CONCLUSION: There were 95.9% pedicles with cancellous channels (grades A, B, and C) can allow pedicle screw fixation and only 4.1% fully corticalized pedicles (grade D) that require an alternative method of fixation. For grade C pedicles (18.5%), pedicle screws can still be attempted with caution. Precautions should also be observed at the L1 and L2 levels as there was a transition to narrower pedicles.
OBJECTIVE: This study aims to investigate variation in the number of thoracic and lumbar vertebrae, the prevalence of lumbosacral transitional vertebra (LSTV) and the prevalence of cervical ribs among surgical patients with adolescent idiopathic scoliosis (AIS).
SUMMARY OF BACKGROUND DATA: Due to variation in the number of thoracic or lumbar vertebrae, inaccurate identification of vertebral levels has been found to be a contributory factor to wrong-level surgery.
METHODS: This was a retrospective study on AIS patients who underwent posterior spinal fusion. Demographic and anthropometric data (age, gender, height, weight, and body mass index), radiographic data (Lenke curve type, pre-operative Cobb angle, vertebra numbering of cervical, thoracic, and lumbar spine, presence of LSTV based on the Castellvi classification and the presence of cervical ribs) and clinical data were collected. Data were analysed and reported with mean and standard deviation for quantitative parameters and number and percentage for qualitative parameters. Multinomial logistic regression analyses were performed to identify factors associated with the outcomes of interest.
RESULTS: A total of 998 patients met inclusion criteria, of which 135 (13.5%) were males and 863 (86.5%) were females. The vertebrae number varied between 23 to 25 total vertebrae with 24 vertebrae considered as the typical number of vertebrae. The prevalence of atypical number of vertebrae (23 or 25) was 9.8% (98 patients). We found a total of 7 different variations in number of cervical, thoracic, and lumbar vertebrae (7C11T5L, 7C12T4L, 7C11T6L, 7C12T5L, 7C13T4L, 7C12T6L, and 7C13T5L) with 7C12T5L considered as the typical vertebrae variation. The total prevalence of patients with atypical vertebrae variation was 15.5% (155 patients). Cervical ribs were found in 2 (0.2%) patients while LSTV were found in 250 (25.1%) of patients. The odds of 13 thoracic vertebrae were higher in males (OR 5.17; 95% CI: 1.25, 21.39) and the odds of 6 lumbar vertebrae were higher in LSTV (OR 3.93; 95% CI: 2.58, 6.00).
CONCLUSION: In this series, we identified a total of 7 different variations in the number of cervical, thoracic, and lumbar vertebrae. The total prevalence of patients with atypical vertebrae variation was 15.5%. LSTV was found in 25.1% of the cohort. It is important to ascertain atypical vertebrae variations rather than the absolute number of vertebrae because variants such as 7C11T6L and 7C13T4L may still have typical numbers of vertebrae in total. However, due to the differences in the number of morphologically thoracic and lumbar vetrebrae, there may still be a risk of inaccurate identification.
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.
CONCLUSION: Knowledge on the widths of medial and lateral pedicle walls, their distribution and differences in a scoliotic spine is important for pedicle screw fixation especially during pedicle probing to find the pedicle channel. The medial pedicle wall widths were significantly thicker than lateral pedicle wall widths in AIS patients with major thoracic curves. The right concave periapical region had the thinnest medial pedicle walls.
METHODS: Retrospective study whereby 90 AIS patients (Lenke type 2, 3, 4, and 6) who underwent PSF from 2019 to 2023 were recruited. Twenty-five severe AIS patients were categorized in Gp1 and 65 non-severe AIS patients in Gp2. Propensity score matching (PSM) with one-to-one with nearest neighbor matching (match tolerance 0.05) was performed. Outcomes measured via operation duration of each stage of surgery, blood loss, number of screws, fusion levels and screw density.
RESULTS: Twenty-five patients from each group were matched. Total operative time was significantly higher in Gp1 (168.2 ± 30.8 vs. 133.3 ± 24.0 min, p
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.