OBJECTIVE: To evaluate the impact of preoperative cervical sagittal parameters on the loss of cervical lordosis (LCL) after expansive open-door laminoplasty (EOLP) and explore the optimal predictors. METHODS: A retrospective analysis was performed on the clinical data of 94 patients with cervical spondylotic myelopathy who underwent EOLP from January 2019 to January 2021, including 61 males and 33 females, aged 34 to 75 years old with an average age of(53.1±9.7) years old. Preoperative routine anteroposterior, lateral, and dynamic X-ray films of the cervical and thoracic spine were taken to comprehensively assess various cervical sagittal parameters: T₁ slope (T₁S), C₂-C₇ sagittal vertical axis (C₂-C₇ SVA), C₂-C₇ cervical lordosis (CL), T1 slope-cervical lordosis (T₁S-CL), cervical lordosis/T₁ slope (CL/T₁S), C₂-C₇ cervical range of motion (ROM), thoracic kyphosis (TK), cephalad vertebral level undergoing laminoplasty (CVLL), and C_2,3 disc angle. Statistical analysis was conducted to identify the independent risk factors of preoperative sagittal parameters for postoperative LCL. RESULTS: A total of 94 patients meeting the inclusion and exclusion criteria were enrolled, with a postoperative follow-up period of 12 to 24 months. Pearson correlation analysis showed that T₁S, T₁S-CL, CVLL, and C_2,3 disc angle were significantly correlated with postoperative LCL, while C₂-C₇ SVA, CL, CL/T₁S, C₂-C₇ ROM, and TK had no significant correlation with postoperative LCL. Regression analysis further indicated that T₁S (β=0.426, P<0.001), T₁S-CL (β=0.716, P<0.001), C_2,3 disc angle (β=0.351, P<0.001), and CVLL (β=-3.348, P<0.001) were significantly correlated with postoperative LCL. CONCLUSION For patients with cervical spondylotic myelopathy treated with EOLP, T₁S, T₁S-CL, CVLL, and C_2,3 disc angle are important factors for predicting cervical lordosis loss, among which CVLL may be the most critical predictive indicator.
Humans ; Male ; Female ; Middle Aged ; Laminoplasty/methods* ; Aged ; Cervical Vertebrae/physiopathology* ; Retrospective Studies ; Adult ; Lordosis/surgery* ; Spondylosis/surgery*

OBJECTIVES: To study genotype-phenotype correlations in children with FGFR3 variants and to improve clinical recognition of related disorders. METHODS: Clinical data of 95 patients aged 0-18 years harboring FGFR3 variants, confirmed by whole‑exome sequencing at Shanghai Children's Medical Center from January 2012 to December 2023, were retrospectively reviewed. Detailed phenotypic characterization was performed for 22 patients with achondroplasia (ACH) and 10 with hypochondroplasia (HCH). RESULTS: Among the 95 patients, 52 (55%) had ACH, 24 (25%) had HCH, 9 (9%) had thanatophoric dysplasia, 3 (3%) had syndromic skeletal dysplasia, 2 (2%) had severe achondroplasia with developmental delay and acanthosis nigricans, and 5 (5%) remained unclassified. A previously unreported FGFR3 variant, c.1663G>T, was identified. All 22 ACH patients presented with disproportionate short stature accompanied by limb dysplasia, commonly with macrocephaly, a depressed nasal bridge, bowed legs, and frontal bossing; complications were present in 17 (77%). The 10 HCH patients predominantly exhibited disproportionate short stature with limb dysplasia and depressed nasal bridge. CONCLUSIONS ACH is the most frequent phenotype associated with FGFR3 variants, and missense variants constitute the predominant variant type. The degree of FGFR3 activation appears to correlate with the clinical severity of skeletal dysplasia.
Humans ; Receptor, Fibroblast Growth Factor, Type 3/genetics* ; Child ; Male ; Child, Preschool ; Female ; Infant ; Adolescent ; Dwarfism/genetics* ; Achondroplasia/genetics* ; Lordosis/genetics* ; Infant, Newborn ; Retrospective Studies ; Genetic Association Studies ; Bone and Bones/abnormalities* ; Phenotype ; Limb Deformities, Congenital

OBJECTIVE: To investigate the relationship among the gross motor function classification system (GMFCS)and the development of hip joint and lumbar spine in children with spastic cerebral palsy. METHODS: The clinical data of 125 children with spastic cerebral palsy admitted from January 2018 to July 2021 were retrospectively analyzed. There were 85 males and 40 females, aged from 4 to 12 years old with an average of (8.4±2.9) years. According to GMFCS, the patients were divided into gradeⅠ, Ⅱ, Ⅲ and Ⅳ groups. There were 27 cases in gradeⅠgroup, 40 cases in gradeⅡgroup, 35 cases in grade Ⅲ group and 23 cases in grade Ⅳ group. The migration percentage(MP), central edge angle(CE), neck-shaft angle(NSA), acetabular index(AI) were measured by the radiograph of pelvis, abnormal parameters were selected to evaluate the relationship between different GMFCS grades and hip joint development. Lumbar sagittal Cobb angle, lumbar sacral angle, lumbar lordosis index and apical distance were measured by lateral lumbar radiographs to evaluate the relationship between different GMFCS grades and lumbar spine development. RESULTS: ①Among the 125 spastic cerebral palsy children, there were 119 cases of pelvic radiographs that met the measurement standards. In the four groups with gradeⅠ, Ⅱ, Ⅲ, Ⅳ, MP was (22.72±3.88), (26.53±4.36), (33.84±4.99), and (49.54±7.87)%, CE was(30.10±6.99) °, ( 22.92±4.19) °, ( 17.91±5.50) °, and (-0.70±17.33)°, AI was (16.41±2.77) °, (20.46±4.63) °, (23.76±5.10) °, and ( 29.15±7.35)°, respectively, there were significant differences between the two comparisons (P<0.05). And the higher GMFCS grade, the greater MP and AI, and the smaller CE.The NSA was(142.74±10.03) °, (148.66±9.09) °, (151.66±10.52) °, and (153.70±8.05)° in four groups with gradeⅠ, Ⅱ, Ⅲ, Ⅳ, respectively. The differences between the two comparisons of the GMFCS gradeⅠgroup and the other three groups were statistically significant (P<0.05). NSA of GMFCSⅠgroup was significantly lower than that of the others, there was no significant difference among other groups(P>0.05). ② Among the 125 spastic cerebral palsy children, there were 88 cases of lumbar spine radiographs that met the measurement standards. ③The lumbar sagittal Cobb angle was(32.62±11.10) °, (29.86±9.90) °, (31.70±11.84) °, and (39.69±6.80)° in the four groups with gradeⅠ, Ⅱ, Ⅲ, Ⅳ, respectively;GMFSS of grade Ⅳ group was significantly higher than that of other three groups, there was significant difference between the two comparisons (P<0.05);there were no significant differences between other groups (P>0.05). In the four groups with gradeⅠ, Ⅱ, Ⅲ, Ⅳ, the lumbosacral angle was (31.02±9.91) °, ( 26.57±9.41) °, (28.08±8.56) °, and ( 27.31±11.50)°, the lumbar lordosis index was (4.14±12.89), (8.83±13.53), (13.00±11.78), and (10.76±9.97) mm, the arch apex distance was (9.50±6.80), (6.68±3.20), (7.16±4.94), and (6.62±4.13) mm, respectively, there were no significant differences between the two comparisons(P>0.05). CONCLUSION ①In children with GMFCS gradeⅠ-Ⅳ, the higher the GMFCS grade, the worse the hip develops. ② Children with GMFCS grade Ⅲ-Ⅳ may be at greater risk for lumbar kyphosis.
Male ; Female ; Humans ; Child ; Child, Preschool ; Lordosis ; Retrospective Studies ; Cerebral Palsy ; Hip Dislocation ; Lumbar Vertebrae/diagnostic imaging* ; Muscle Spasticity

OBJECTIVE: To compare and analyze the feasibility of autologous facet joint bone block as an alternative to polyetheretherketone (PEEK) cage in lumbar intervertebral fusion surgery for patients with osteoporosis. METHODS: From December 2018 to June 2021, the case data of patients with osteoporosis (T value ≤ -2.5 on dual energy X-ray bone density) who underwent posterior lumbar interbody fusion in the Fourth Medical Center, Chinese PLA General Hospital were retrospectively reviewed. All the cases were followed up for no less than 12 months and were divided into two groups according to the differences of interbody fusion materials: the autologous facet joint bone block group (autogenous bone group) and the PEEK cage group (PEEK group). The general data [such as age, gender, body mass index (BMI), primary diagnosis, distribution of fusion segments, bone mineral density of lumbar (BMD), incidence of preoperative complications], the perioperative data (such as duration of operation, intraoperative blood loss, postoperative drainage, perioperative allogeneic blood transfusion rate), and the incidence of postoperative complications were compared between the two groups. Imaging parameters (disc height, lumbar lordosis angle, segment lordosis angle, segmental lordosis angle, disc height improvement rate, and fusion rate) and lumbar functional scores [visual analogue scale (VAS), Oswestry disability index (ODI), Japanese Orthopedics Association (JOA) score for lower back pain] were compared to evaluate the clinical efficacy between the kinds of intervertebral fusion materials 1 week, 3 months and 6 months postoperative and at the last follow-up. RESULTS: A total of 118 patients were enrolled, including 68 cases in the autogenous bone group and 50 cases in the PEEK group, there were no statistical differences in age, gender, BMI, primary diagnosis, distribution of fusion segments, BMD, incidence of preoperative complications, duration of operation, intraoperative blood loss, postoperative drainage, perioperative allogeneic blood transfusion rate, incidence of postoperative complications, all the preoperative imaging parameters and all the lumbar function scores between the two groups (P>0.05). Postoperative superficial surgical site infections occurred in 3 patients in the autogenous bone group and 2 patients in the PEEK group. At the last follow-up, 3 cases of intervertebral graft collapse occurred in the autogenous bone group and 5 cases in the PEEK group, 1 case of graft subsidence in the autogenous bone group and 1 case in the PEEK group. All the imaging parameters showed significant differences between postoperation and preoperation (P < 0.05), and all the imaging parameters showed significant differences between 1 week and 3 months postoperative in both groups (P < 0.05). The height, angle of fusion gap in the autogenous bone group were lower than those in the PEEK group 1 week postoperatively (P < 0.05), and the fusion gap height improvement rate in the autogenous bone group was lower than that in the PEEK group (P < 0.05). The cases in both groups started to show final fusion 3 months after surgery, and the fusion rate in the autogenous bone group was 75% 6 months postoperatively, which was significantly higher than the rate of 56% in the PEEK group (P < 0.05), and there was no statistically significant difference in the final fusion rate between the two groups (P>0.05). The ODI, the postoperative VAS score was significantly lower than that in preoperation, while the postoperative JOA score was significantly higher than that in preoperation (P < 0.05). The ODI was lower while the JOA score was higher of the autogenous bone group than that of the PEEK group 6 months postoperatively (P < 0.05). CONCLUSION In osteoporosis patients, good interbody fusion rate and improvement of lumbar vertebral function can be obtained by using autologous facet joint bone block or PEEK cage, while the fusion rate and the improvement of lumbar function with autologous facet joint bone block are better than those with PEEK cage 6 months post-operatively. PEEK cage is superior to autologous facet joint bone block in intervertebral distraction and improvement of lumbar lordosis. Significant disc space subsidence occurred in osteoporotic patients within 3 months after lumbar interbody fusion, and the subsidence of PEEK cage was more obvious than that of autologous facet joint bone block.
Humans ; Retrospective Studies ; Lordosis ; Zygapophyseal Joint ; Spinal Fusion/methods* ; Polyethylene Glycols/therapeutic use* ; Treatment Outcome ; Ketones ; Lumbar Vertebrae/surgery* ; Osteoporosis ; Blood Loss, Surgical ; Postoperative Complications ; Postoperative Hemorrhage

OBJECTIVE: To introduce a scout view scanning technique of back-forward bending CT (BFB-CT) in simulated surgical position for evaluating the remaining real angle and flexibility of thoracolumbar kyphosis secondary to old osteoporotic vertebral compression fracture. METHODS: A total of 28 patients with thoracolumbar kyphosis secondary to old osteoporotic vertebral compression fracture who met the selection criteria between June 2018 and December 2021 were included in the study. There were 6 males and 22 females with an average age of 69.5 years (range, 56-92 years). The injured vertebra were located at T ₁₀-L ₂, including 11 cases of single thoracic fracture, 11 cases of single lumbar fracture, and 6 cases of multiple thoracolumbar fractures. The disease duration ranged from 3 weeks to 36 months, with a median of 5 months. All patients received examinations of BFB-CT and standing lateral full-spine X-ray (SLFSX). The thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), local kyphosis of injured vertebra (LKIV), lumbar lordosis (LL), and the sagittal vertical axis (SVA) were measured. Referring to the calculation method of scoliosis flexibility, the kyphosis flexibility of thoracic, thoracolumbar, and injured vertebra were calculated respectively. The sagittal parameters measured by the two methods were compared, and the correlation of the parameters measured by the two methods was analyzed by Pearson correlation. RESULTS: Except LL ( P>0.05), TK, TLK, LKIV, and SVA measured by BFB-CT were significantly lower than those measured by SLFSX ( P<0.05). The flexibilities of thoracic, thoracolumbar, and injured vertebra were 34.1%±18.8%, 36.2%±13.8%, and 39.3%±18.6%, respectively. Correlation analysis showed that the sagittal parameters measured by the two methods were positively correlated ( P<0.001), and the correlation coefficients of TK, TLK, LKIV, and SVA were 0.900, 0.730, 0.700, and 0.680, respectively. CONCLUSION Thoracolumbar kyphosis secondary to old osteoporotic vertebral compression fracture shows an excellent flexibility and BFB-CT in simulated surgical position can obtain the remaining real angle which need to be corrected surgically.
Male ; Female ; Humans ; Aged ; Fractures, Compression/surgery* ; Spinal Fractures/diagnostic imaging* ; Lumbar Vertebrae/surgery* ; Thoracic Vertebrae/surgery* ; Kyphosis/surgery* ; Osteoporotic Fractures/surgery* ; Lordosis ; Tomography, X-Ray Computed ; Retrospective Studies

OBJECTIVE: To investigate the feasibility of predicting proximal junctional kyphosis (PJK) in adults after spinal deformity surgery based on back-forward Bending CT localization images and related predictive indicators. METHODS: A retrospective analysis was performed for 31 adult patients with spinal deformity who underwent posterior osteotomy and long-segment fusion fixation between March 2017 and March 2020. There were 5 males and 26 females with an average age of 62.5 years (range, 30-77 years). The upper instrumented vertebrae (UIV) located at T ₅ in 1 case, T ₆ in 1 case, T ₉ in 13 cases, T ₁₀ in 12 cases, and T ₁₁ in 4 cases. The lowest instrumented vertebrae (LIV) located at L ₁ in 3 cases, L ₂ in 3 cases, L ₃ in 10 cases, L ₄ in 7 cases, L ₅ in 5 cases, and S ₁ in 3 cases. Based on the full-length lateral X-ray film of the spine in the standing position before and after operation and back-forward Bending CT localization images before operation, the sagittal sequence of the spine was obtained, and the relevant indexes were measured, including thoracic kyphosis (TK), lumbar lordosis (LL), local kyphosis Cobb angle (LKCA) [the difference between the different positions before operation (recovery value) was calculated], kyphosis flexibility, hyperextension sagittal vertical axis (hSVA), T ₂-L ₅ hyperextension C ₇-vertebral sagittal offset (hC ₇-VSO), and pre- and post-operative proximal junctional angle (PJA). At last follow-up, the patients were divided into PJK and non-PJK groups based on PJA to determine whether they had PJK. The gender, age, body mass index (BMI), number of fusion segments, number of cases with coronal plane deformity, bone mineral density (T value), UIV position, LIV position, operation time, intraoperative blood loss, osteotomy grading, and related imaging indicators were compared between the two groups. The hC ₇-VSO of the vertebral body with significant differences between groups was taken, and the receiver operating characteristic curve (ROC) was used to evaluate its accuracy in predicting the occurrence of PJK. RESULTS: All 31 patients were followed up 13-52 months, with an average of 30.0 months. The patient's PJA was 1.4°-29.0° at last follow-up, with an average of 10.4°; PJK occurred in 8 cases (25.8%). There was no significant difference in gender, age, BMI, number of fusion segments, number of cases with coronal plane deformity, bone mineral density (T value), UIV position, LIV position, operation time, intraoperative blood loss, and osteotomy grading between the two groups ( P>0.05). Imaging measurements showed that the LL recovery value and T ₈-L ₃ vertebral hC ₇-VSO in the PJK group were significantly higher than those in the non-PJK group ( P>0.05). There was no significant difference in hyperextension TK, hyperextension LL, hyperextension LKCA, TK recovery value, LL recovery value, kyphosis flexibility, hSVA, and T ₂-T ₇, L ₄, L ₅ vertebral hC ₇-VSO ( P>0.05). T ₈-L ₃ vertebral hC ₇-VSO was analyzed for ROC curve, and combined with the area under curve and the comprehensive evaluation of sensitivity and specificity, the best predictive index was hC ₇-L ₂, the cut-off value was 2.54 cm, the sensitivity was 100%, and the specificity was 60.9%. CONCLUSION Preoperative back-forward Bending CT localization image can be used to predict the occurrence of PJK after posterior osteotomy and long-segment fusion fixation in adult spinal deformity. If the patient's T ₈-L ₂ vertebral hC ₇-VSO is too large, it indicates a higher risk of postoperative PJK. The best predictive index is hC ₇-L ₂, and the cut-off value is 2.54 cm.
Male ; Female ; Humans ; Adult ; Middle Aged ; Retrospective Studies ; Blood Loss, Surgical ; Thoracic Vertebrae/surgery* ; Kyphosis/surgery* ; Lordosis/surgery* ; Spinal Fusion/methods* ; Tomography, X-Ray Computed ; Postoperative Complications/diagnostic imaging* ; Lumbar Vertebrae/surgery*

OBJECTIVE: To investigate the changes in spinal-pelvic sagittal parameters from preoperative standing to prone position in old traumatic spinal fractures with kyphosis. METHODS: The clinical data of 36 patients admitted between December 2016 and June 2021 for surgical treatment of old traumatic spinal fractures with kyphosis, including 7 males and 29 females, aged from 50 to 79 years (mean, 63.9 years), were retrospectively analyzed. Lesion segments included 2 cases of T ₁₁, 12 cases of T ₁₂, 2 cases of T _{11, 12}, 4 cases of T ₁₂ and L ₁, 12 cases of L ₁, 2 cases of L ₂, 1 case of L _{2, 3}, and 1 case of L ₃. The disease duration ranged from 4 to 120 months, with an average of 19.6 months. Surgical procedures included Smith-Petersen osteotomy in 4 cases, Ponte osteotomy in 6 cases, pedicle subtraction osteotomy in 2 cases, and improved fourth level osteotomy in 18 cases; the remaining 6 cases were not osteotomized. The bone mineral density ranged from -3.0 to 0.5 T, with a mean of -1.62 T. The spinal-pelvic sagittal parameters from preoperative standing to prone positions were measured, including local kyphosis Cobb angle (LKCA), thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), and PI and LL mismatch (PI-LL). The kyphotic flexibility=(preoperative standing LKCA-preoperative prone LKCA)/preoperative standing LKCA×100%. Spinal-pelvic sagittal parameters were compared between standing position and prone position before operation, and Pearson correlation was used to judge the correlation between the parameters of standing position and prone position before operation. RESULTS: When the position changed from standing to prone, LKCA and TK decreased significantly ( P<0.05), while SS, LL, PT, and PI-LL had no significant difference ( P>0.05). Pearson correlation analysis showed that LL was significantly correlated with SS and PI-LL in both standing and prone positions ( P<0.05), and the correlation strength between LL and SS in prone position was higher than that in standing position. In the standing position, LKCA was significantly correlated with SS and PT ( P<0.05). However, when the position changed from standing to prone, the correlation between LKCA and SS and PT disappeared, while PT and PI-LL was positive correlation ( P<0.05). The kyphotic flexibility was 25.13%-78.79%, with an average of 33.85%. CONCLUSION For the patients of old traumatic spinal fractures with kyphosis, the preoperative LKCA and TK decrease significantly from standing position to prone position, and the correlation between spinal and pelvic parameters also changed, which should be taken into account in the formulation of preoperative surgical plan.
Male ; Female ; Humans ; Spinal Fractures/surgery* ; Standing Position ; Retrospective Studies ; Lumbar Vertebrae/surgery* ; Kyphosis/surgery* ; Lordosis/surgery*

OBJECTIVE: To compare the short-term clinical efficacy and radiologic differences between oblique lateral interbody fusion(OLIF) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for degenerative lumbar spondylolisthesis. METHODS: A retrospective analysis was performed on 58 patients with lumbar spondylolisthesis treated with OLIF or MIS-TLIF from April 2019 to October 2020. Among them, 28 patients were treated with OLIF (OLIF group), including 15 males and 13 females aged 47 to 84 years old with an average age of (63.00±9.38) years. The other 30 patients were treated with MIS-TLIF(MIS-TLIF group), including 17 males and 13 females aged 43 to 78 years old with an average age of (61.13±11.10) years. General conditions, including operation time, intraoperative blood loss, postoperative drainage, complications, lying in bed, and hospitalization time were recorded in both groups. Radiological characteristics, including intervertebral disc height (DH), intervertebral foramen height (FH), and lumbar lordosis angle (LLA), were compared between two groups. The visual analogue scale (VAS) and Oswestry disability index (ODI) were used to evaluate the clinical effect. RESULTS: The operation time, intraoperative blood loss, postoperative drainage, lying in bed, and hospitalization time in OLIF group were significantly less than those in the MIS-TLIF group (P<0.05). The intervertebral disc height and intervertebral foramen height were significantly improved in both groups after the operation (P<0.05). The lumbar lordosis angle in OLIF group was significantly improved compared to before the operation(P<0.05), but there was no significant difference in the MIS-TLIF group before and after operation(P>0.05). Postoperative intervertebral disc height, intervertebral foramen height, and lumbar lordosis were better in the OLIF group than in the MIS-TLIF group (P<0.05). The VAS and ODI of the OLIF group were lower than those of the MIS-TLIF group within 1 week and 1 month after the operation (P<0.05), and there were no significant differences in VAS and ODI at 3 and 6 months after the operation between the two groups(P>0.05). In the OLIF group, 1 case had paresthesia of the left lower extremity with flexion-hip weakness and 1 case had a collapse of the endplate after the operation;in the MIS-TLIF group, 2 cases had radiation pain of lower extremities after decompression. CONCLUSION Compared with MIS-TLIF, OLIF results in less operative trauma, faster recovery, and better imaging performance after lumbar spine surgery.
Male ; Female ; Humans ; Middle Aged ; Aged ; Aged, 80 and over ; Adult ; Retrospective Studies ; Spondylolisthesis/surgery* ; Lumbar Vertebrae/surgery* ; Lordosis/surgery* ; Minimally Invasive Surgical Procedures/methods* ; Spinal Fusion/methods* ; Treatment Outcome ; Blood Loss, Surgical ; Postoperative Hemorrhage

OBJECTIVE: To determine whether C₇ angles (C₇ slope, C₇S) could replace T₁ angles (T₁ slope, T₁S) by correlation analysis of T₁S and C₇S. METHODS: A total of 442 patients from July 2015 to July 2020 in outpatient and inpatient department were enrolled retrospectively, and 259 patients who could identify the upper endplate of T₁ were screened out . Of them, there were 145 males and 114 females, aged from 20 to 83 years old with an average of (58.6±11.2) years, including 163 patients with cervical spine surgery and 96 non-surgical patients. Patients were stratified by sex, age, cervical kyphosis, cervical alignment imbalance, and cervical spine surgery. These 259 patients included 145 cases in the male group, 114 cases in the female group;76 cases in the youth group (<40 years old), 109 cases in the middle-aged group (40 to 60 years old), and 74 cases in the elderly group(>60 years old); 92 cases in the cervical kyphosis group, 167 cases in the non-kyphosis group;51 cases in the cervical sequence imbalance group, 208 cases in the non-imbalance group;163 cases in the cervical surgery group, 96 cases in the non-operation group. The correlations of C₇S and T₁S in various modalities groups were analyzed. RESULTS: Of 442 patients, the recognition rate of upper endplate of T₁ was 58.6%(259/442), and that of C₇ was 90.7%. The mean T₁S and C₇S of the 259 patients were (24.5±8.0)° [(25.9±7.7)° in the male group and (23.7±6.9)° in the female group] and (20.8±7.3)° [(22.5±7.5)° in the male group and(19.7±5.8)° in the female group], respectively. The total correlation coefficient between C₇S and T₁S was r=0.89, R²=0.79, and the linear regression equation was T₁S=0.91×C₇S+4.35. In the above general information and the grouping of deformity factors, T₁S was highly correlated with C₇S(r value 0.85 to 0.92, P<0.05). CONCLUSION There is a high correlation between T₁S and C₇S in different factor groups. For cases where T₁S cannot be measured, C₇S can be used to provide guidance and reference for evaluating the sagittal balance of the spine, analyzing the condition, and formulating surgical plans.
Middle Aged ; Adolescent ; Humans ; Male ; Female ; Aged ; Young Adult ; Adult ; Aged, 80 and over ; Lordosis/surgery* ; Retrospective Studies ; Cervical Vertebrae/surgery* ; Kyphosis/surgery* ; Neck

OBJECTIVE: To explore the normal distribution of cervical sagittal alignment and the relationship between cervical alignment and global spine balance in asymptomatic young adults. METHODS: A cohort of 272 asymptomatic Chinese adults (including 161 males and 111 females, with an average age of (23.2±4.4) years, ranging from 18 to 45 years) were prospectively recruited from November 2011 to December 2014. The C₀-C₂ angle, disk angles from C₂-C₃ to C₆-C₇, vertebral angles from C₃ to C₇, T₁ slope, thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), C₂-C₇ sagittal vertical axis (C₂-C₇SVA), center of gravity of head to C₇SVA (CGH-C₇SVA), C₇-S₁SVA were measured and statistically analyzed. All the subjects were categorized with the Roussouly classification and the cervical morphologies were evaluated as lordotic, straight, sigmoid or kyphotic. Spinal sagittal alignment parameters were compared between different sexes and Roussouly classifications with independent student t test, analysis of variance (ANOVA) or Chi-square test. Correlations between cervical sagittal alignment and global spine sagittal alignment were calculated using the Pearson and Spearman correlation coefficient. Linear regression analysis was performed. RESULTS: Sixty-seven males and 59 females aged from 18 to 30 years old were included in the study. The mean value of C₀-C₇ was 26.0°±12.8°, composed of 15.2°±6.7° for C₀-C₂, 9.1°±12.1° for sum of disk angles from C₂-C₃ to C₆-C₇, and 1.4°±10.2° for sum of vertebral angles from C₃ to C₇. C₂-C₇SVA [(18.6±7.9) mm] and CGH-C₇SVA [(22.9±12.3) mm]were offset ideally by C₇-S₁SVA [(-21.6±31.0) mm]. Males had a larger T₁ slope (P < 0.05) and accordingly, a larger cervical lordosis C₂-C₇ (P < 0.01) and C₀-C₇ angle (P < 0.01) than females. Males had a smaller C₇-S₁SVA (P < 0.01) and accordingly, a smaller CGH-C₇SVA (P=0.165) than females. Significant difference was found between cervical alignment of different Roussouly types (P < 0.01). In general, a larger LL was consistent with a set of larger TK, C₂-C₇angle, C₀-C₇ angle, and vice versa. There was no significant correlation between cervical morphology and the Roussouly classification (Chi-square=10.548, P=0.308). There was significant correlation between cervical alignment and T₁ slope (P < 0.01), TK (P < 0.01). There was significant correlation between adjacent segmental angles from T₁ slope up to C₀-C₂ angle (P < 0.05). CONCLUSION Normative values of each vertebral angle and disk angle were established. The cervical lordosis occurred mainly at C₀-C₂ and disk levels, which was influenced by parameters of other parts of the spine, such as T₁ slope, TK and the Roussouly classification. There was significant correlation between adjacent disk angles.
Adolescent ; Adult ; Cervical Vertebrae/diagnostic imaging* ; China ; Female ; Humans ; Kyphosis ; Lordosis/diagnostic imaging* ; Male ; Thoracic Vertebrae ; Young Adult