OBJECTIVE: To investigate the effect of expansive open-door laminoplasty combined with single lateral mass screw fixation on the posterior longitudinal ligament ossification and cervical instability and its effect on sagittal balance. METHODS: A retrospective analysis of 65 patients with the posterior longitudinal ligament with cervical instability from May 2012 to July 2018 was conducted. The patients were divided into two groups according to the surgical method. Thirty-four patients were treated with open-door laminoplasty including 19 males and 15 females, aged 49 to 60 years old with an average age of (54.4±4.77) years old;symptoms lasted 8 to 39 months with an average of (21.0±8.2) months. Thirty-one patients were treated with single-door laminoplasty combined with single mass screw fixation including 17 males and 14 females, aged 50 to 59 years old with an average age of (55.4±3.2) years;symptoms lasted 7 to 48 months with an average of (23.7±13.1) months. General information of the two groups, including operation time, intraoperative blood loss, and postoperative complications was recorded. Sagittal vertical axis(SVA), C₀-C₂ and C₂-C₇ cobb angle were measured by X-ray before operation and at the last follow-up. Clinical efficacy was evaluated using the Japanese Orthopaedic Association(JOA) score. RESULTS: Surgery was successful in all patients. The operation time (109±15) min in the single-door laminoplasty combined with lateral mass screw fixation group was longer than that in the single-door group(128±16) min(P<0.05). There was no significant difference in intraoperative blood loss, postoperative axial symptoms and follow-up time between two groups(P>0.05). At the latest follow-up, both groups showed significant improvement in the motor and sensory components of the JOA score and the total JOA score compared to pre-surgery(P<0.05) and no significant change in bladder function score(P>0.05). There was no significant difference between two groups(P>0.05). At the latest follow-up, the C₀-C₂ Cobb angle increased in both groups compared to preoperative and more the single-door laminoplasty group(P<0.05). The angle of the C₂-C₇ Cobb angle decreased in both groups, and the reduction was greater in the single-door laminoplasty combined with lateral mass screw fixation group(P<0.05). There was a significant increase in C₂-C₇ SVA in the single-door laminoplasty group(P<0.05) and no significant change the single-door laminoplasty combined with lateral screw fixation group(P>0.05). CONCLUSION Posterior cervical laminoplasty with unilateral lateral mass screw fixation combined with single-door vertebral plate shaping surgery improves the neurological function and quality of life in patients with cervical spondylotic myelopathy complicated by ossification of the posterior longitudinal ligament and cervical instability. Compared with single-door vertebral plate shaping surgery, postoperative cervical lordosis and forward-tilt can be improved.
Humans ; Middle Aged ; Male ; Female ; Laminoplasty/methods* ; Ossification of Posterior Longitudinal Ligament/physiopathology* ; Bone Screws ; Cervical Vertebrae/physiopathology* ; Retrospective Studies ; Joint Instability/surgery*

OBJECTIVE: Objective To investigate the relationship between cervical disc herniation and C₀-C₂ Cobb angle. METHODS: The clinical data of 301 patients with cervical disc herniation from 2020 to 2024 were retrospectively analyzed. The median value of C₀-C₂ Cobb angle measurements from 301 patients was used as the boundary, cervical disc herniation patients were divided into two groups, C₀-C₂ Cobb angle <28.50 group and 151 patients with C₀-C₂ Cobb angle≥28.50 group. Among them, 150 patients in C₀-C₂ Cobb angle <28.50 group included 53 males and 97 females, aged 23 to 76 (57.32±12.55) years, with a disease duration of 7 to 19 (13.81±5.32) months;the othor 151 patients with C₀-C₂ Cobb angle≥28.50 group including 61 males and 90 females, aged 25 to 74 (56.86±12.51) years, with a disease duration of 8 to 18 (14.13±5.56) months. The cervical lordosis angle (C₀-C₂ Cobb angle and C₂-C₇ Cobb angle), T₁ inclination slope (T₁S) and cervical sagittal axial distance (C₂-C₇ SVA) were measured on the lateral cervical radiographs. The correlation between C₀-C₂ Cobb angle and cervical disc herniation range, protrusion position, average protrusion size and other parameters was analyzed. RESULTS: When the C₀-C₂ Cobb angle<28.50°, the average protrusion size was (2.21±0.56) mm, the C₂-C₇ Cobb angle was (19.92±12.06)° and the C₂-C₇ SVA was (1.10±1.20) mm. When the C₀-C₂ Cobb angle≥28.50°, the average protrusion size was (2.38±0.60) mm, the C₂-C₇ Cobb angle was (12.01±13.09 )°, the C₂-C₇ SVA was (1.53±1.36) mm, and the difference was statistically significant (P<0.05). Between the two groups of patients with C₀-C₂ Cobb angle < 28.50° and C₀-C₂ Cobb angle≥28.50°, there were significant differences in the size of C_3,4, C_4,5, C_5,6, C_6,7, C₇, T₁ disc herniation in single segment (P<0.05 ). C₀-C₂ Cobb angle was correlated with age(r=-0.135, P<0.05 ), C₂-C₇ Cobb angle (r=-0.382, P<0.01 ), C₂-C₇ SVA (r=0.293, P<0.01), average protrusion size (r=0.139, P<0.05), and the size of C_3,4 (r=0.215, P<0.01 ), C_4,5 (r=0.176, P<0.01 ), C_5,6 (r=0.144, P<0.05 ), C_6,7 (r=0.158, P<0.05 ), C₇T₁ (r=0.535, P<0.05) disc herniation. CONCLUSION There is a positive correlation between C₀-C₂ Cobb angle and the size of cervical disc herniation. C₀-C₂ Cobb angle can reflect the degree of cervical disc herniation. Previous studies have shown that the biomechanical changes between C₀-C₂ Cobb angle, C₂-C₇ Cobb angle, C₂-C₇ SVA and cervical extensor muscle group may be risk factors for accelerating cervical disc herniation and this may be one of the mechanisms that C₀-C₂ Cobb angle is positively correlated with the size of cervical disc herniation.
Humans ; Male ; Female ; Middle Aged ; Intervertebral Disc Displacement/physiopathology* ; Adult ; Cervical Vertebrae/diagnostic imaging* ; Aged ; Retrospective Studies ; Young Adult

OBJECTIVE: To explore the effect of nano-hydroxyapatite/collagen composite (nHAC) on bone graft fusion after anterior cervical discectomy and fusion (ACDF) in patients with cervical spondylosis and low bone mass. METHODS: A retrospective analysis was conducted on 47 patients with low bone mass who underwent ACDF from 2017 to 2021. They were divided into the nHAC group and the allogeneic bone group according to different bone graft materials. The nHAC group included 26 cases, with 8 males and 18 females;aged 50 to 78 years old with an average of (62.81±7.79) years old;the CT value of C₂-C₇ vertebrae was (264.16±36.33) HU. The allogeneic bone group included 21 cases, with 9 males and 12 females;aged 54 to 75 years old with an average of (65.95±6.58) years old;the CT value of C₂-C₇ vertebrae was (272.39±40.44) HU. The visual analogue scale (VAS), neck disability index (NDI), and Japanese Orthopaedic Association (JOA) spinal cord function score were compared before surgery, 1 week after surgery, and at the last follow-up to evaluate the clinical efficacy. Imaging assessment included C₂-C₇ Cobb angle, surgical segment height, intervertebral fusion, and whether the cage subsidence occurred at 1 week after surgery and the last follow-up. RESULTS: The follow-up duration ranged from 26 to 39 months with an average of (33.27±3.34) months in the nHAC group and 26 to 41 months with an average of (31.86±3.57) months in the allogeneic bone group. At 1 week after surgery and the last follow-up, the VAS, NDI scores, and JOA scores in both groups were significantly improved compared with those before surgery, with statistically significant differences (P<0.05). At 1 week after surgery, the C₂-C₇ Cobb angles in the nHAC group and the allogeneic bone group were (14.26±10.32)° and (14.28±8.20)° respectively, which were significantly different from those before surgery (P<0.05). At the last follow-up, the C₂-C₇ Cobb angles in both groups were smaller than those at 1 week after surgery, with statistically significant differences (P<0.05). At 1 week after surgery, the height of the surgical segment in the nHAC group was (31.65±2.55) mm, and that in the allogeneic bone group was (33.63±3.26) mm, which were significantly different from those before surgery (P<0.05). At the last follow-up, the height of the surgical segment in both groups decreased compared with that at 1 week after surgery, with statistically significant differences (P<0.05). At the last follow-up, 39 surgical segments were fused and 6 cages subsided in the nHAC group;40 surgical segments were fused and 7 cages subsided in the allogeneic bone group;there was no statistically significant difference between the two groups (P>0.05). Compared with the CT value of vertebrae without cage subsidence, the CT value of vertebrae with cage subsidence in both groups was significantly lower, with a statistically significant difference (P<0.05). CONCLUSION The application of nHAC in ACDF for patients with low bone mass can achieve effective fusion of the surgical segment. There is no significant difference in improving clinical efficacy, intervertebral fusion, and cage subsidence compared with the allogeneic bone group. With the extension of follow-up time, the C₂-C₇ Cobb angle decreases, the height of the surgical segment is lost, and the cage subsides in both the nHAC group and the allogeneic bone group, which may be related to low bone mass. Low bone mass may be one of the risk factors for cervical spine sequence changes, surgical segment height loss, and cage subsidence after ACDF.
Humans ; Male ; Female ; Middle Aged ; Spondylosis/physiopathology* ; Spinal Fusion/methods* ; Cervical Vertebrae/surgery* ; Aged ; Diskectomy ; Durapatite ; Retrospective Studies ; Collagen/chemistry*

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*

OBJECTIVE: To explore the optimal vertical traction weight, clinical efficacy, and safety of bidirectional cervical traction in the treatment of cervical kyphosis. METHODS: A total of 130 patients with neck pain and cervical kyphosis confirmed by cervical DR who visited the hospital from April 2023 to April 2024 were enrolled. They were divided into 4 groups according to the vertical traction weight accounting for 5%, 10%, 15%, and 20% of their body weight, respectively. The 5% body weight traction group included 33 cases (13 males and 20 females) with an average age of (34.00±10.58) years old;the 10% body weight traction group included 35 cases (17 males and 18 females) with an average age of (32.23±8.39) years old;the 15% body weight traction group included 32 cases (14 males and 18 females) with an average age of (33.88±10.09) years old;the 20% body weight traction group included 30 cases (11 males and 19 females) with an average age of (36.20±9.13) years old. Each group received treatment for 2 weeks. The visual analogue scale (VAS) score, neck disability index (NDI), and C₂-C₇ Cobb angle on cervical lateral X-ray films before and after treatment were recorded to evaluate the clinical efficacy of the 4 groups. RESULTS: When the traction weight was 10% and 15% of body weight, the pain VAS and NDI were significantly improved, and the C₂-C₇ Cobb angle increased, with statistically significant differences (P<0.05), and no adverse reactions occurred. However, in the 5% body weight group, the above indicators showed no significant changes, with no statistically significant differences (P>0.05). In the 20% body weight group, some patients could not tolerate the treatment, and adverse reactions such as dizziness, nausea, and aggravated neck pain occurred. CONCLUSION The optimal vertical traction weight of bidirectional cervical traction for cervical kyphosis is 10%-15% of body weight, which can effectively improve neck pain and cervical function, increase the C₂-C₇ Cobb angle of the cervical spine, with high safety, and is worthy of promotion and application.
Humans ; Male ; Female ; Traction/methods* ; Kyphosis/physiopathology* ; Adult ; Cervical Vertebrae/physiopathology* ; Middle Aged ; Neck Pain ; Young Adult

OBJECTIVE: To establish a two-segment vertebrectomy model using the finite element method, and to measure and compare the biomechanical properties of the lower cervical anterior transpedicular root screw (ATPRS) plate system, lower cervical anterior pedicle screw (ATPS) plate system, and lower cervical anterior cervical locked-plate (ACLP) system on this model. METHODS: CT data of the cervical spine (C₀-T₁) from a 34-year-old healthy adult male volunteer were collected. A nonlinear complete model of the lower cervical spine (C₃-C₇) was established using Mimics 10.01 software, based on which the ATPRS fixation model, ATPS fixation model, and ACLP fixation model were constructed respectively. An axial pressure of 75 N and a pure couple moment of 1.5 N·m were applied to C3 to make the model perform flexion-extension, left-right lateral bending, and left-right rotation movements. The range of motion (ROM) and stress distribution of each model under different working conditions were compared. RESULTS: The ROM of the C₄-C₇ segments in the ACLP group, ATPS group, and ATPRS group was reduced to 0.65° (-95.2%), 0.58° (-95.7%), and 0.62° (-95.4%) respectively compared with the intact model during flexion-extension movement;during lateral bending movement, it was reduced to 0.58° (-95.2%), 0.51°(-95.8%), and 0.60° (-95.1%) respectively;during rotation movement, it was reduced to 1.17° (-89.6%), 1.26° (-88.8%), and 1.27°(-88.7%) respectively. In terms of the stress on the titanium mesh graft, the ATPS group and ATPRS group had the maximum load during extension and the minimum load during flexion. Compared with the ACLP group, the stress on the titanium mesh graft in ATPS and ATPRS decreased by (-33.7%) and (-15.8%) in flexion, (-29.4%) and (-13.2%) in extension, (-26.2%) and (-23.4%) in lateral bending, and (-18.8%) and (-5.4%) in rotation, respectively. In terms of bone-screw interface stress, the peak bone stress near the C₇ screw in the ACLP group, ATPS group, and ATPRS group increased by 49.2%, 45.0%, and 47.6% respectively compared with the peak bone stress near the C₄ screw during extension. However, during flexion and lateral bending, there was no significant difference in the peak bone stress near the C₄ and C₇ screws. During rotation, the difference between the peak bone stress near the C₄ screw and that near the C₇ screw showed that in the ACLP group, left rotation (37.6%) was similar to right rotation (36.7%), while in the ATPS group and ATPRS group, left rotation was lower than right rotation. CONCLUSION Compared with the ACLP group, the ATPS group and ATPRS group have greater fixation stiffness and more stable fixation. However, in rotational movement, due to the uneven distribution of fixation stiffness, the stress distribution during torsion is uneven, but it is still better than the ACLP group. This indicates that ATPRS, like ATPS, has good primary stability, providing favorable conditions for bone graft fusion.
Humans ; Finite Element Analysis ; Male ; Cervical Vertebrae/physiopathology* ; Adult ; Biomechanical Phenomena ; Bone Plates ; Bone Screws ; Range of Motion, Articular ; Fracture Fixation, Internal

OBJECTIVE: To explore the changes of stress and displacement of intervertebral discs and vertebral bodies in adolescent idiopathic cervical kyphosis models caused by Wuqinxi () Huju() and extension movement after torque loading by finite element analysis. METHODS: One healthy male volunteer aged 24-year-old (heighted 178 cm and weighted 65 kg) was selected, software such as Mimics 21.0, Geomagic wrap 2017, SolidWorks 2017, and Ansys Workbench 17.0 were used to simulate adolescent idiopathic cervical spine model, an axial compressive load of 266 N was applied to the center of the end plate on C₂ for head physical gravity simulation, the lower part of C₇ vertebral body was set as the point of freedom constraint, a torque of 1.5 N·m was applied with C₂ as the reference point to simulate the stress on intervertebral discs and vertebral bodies after 45° movement of Wuqinxi () Huju (). RESULTS: The normal C₂-C₇ cervical spine model and adolescent idiopathic cervical kyphosis model were successfully constructed. The maximum stress value of intervertebral disc when the Huju()was raised and extended at 45° and loaded with torque occurred in C_3,4 intervertebral disc (3.588 1) MPa. The maximum stress values of each intervertebral disc were C_3,4(3.588 1 MPa)>C_2,3 (3.467 5 MPa) >C_4,5(2.597 7 MPa) >C_5,6 (2.378 8 MPa) >C_6,7 (1.404 9 MPa), respectively. The maximum stress of C6 vertebral body was 5.842 9 MPa, while the stresses of C₂, C₃, C₄, and C₅ vertebral bodies was 4.184 8, 4.437 8, 4.148 7, and 2.852 4 MPa respectively. The overall stress of vertebral body was mainly concentrated in the front of vertebral body. CONCLUSION After long-term practice of Huju()movement, the stress concentration in intervertebral discs and the front of vertebral body changes the stress load state of intervertebral discs and vertebral body. As time goes by, intervertebral discs may change, forming a shape that is higher in the front and lower in the back. The vertebral body may also undergo remodeling, resulting in a relative increase in the height of the anterior edge of vertebral body and promoting the recovery of cervical kyphosis to a physiological lordosis state.
Humans ; Finite Element Analysis ; Male ; Cervical Vertebrae/physiopathology* ; Kyphosis/therapy* ; Young Adult ; Adolescent ; Adult

OBJECTIVE: To compare the biomechanical properties of four internal fixation methods in a lower cervical spine injury model using the finite element method. METHODS: Cervical CT data of a 28-year-old healthy adult male were utilized to establish a finite element model of the normal cervical spine and a lower cervical spine three-column injury model. Four internal fixation methods were then applied to the three-column injury model, resulting in four groups:Group A, anterior cervical locked-plate(ACLP) fixation system model(anterior approach);Group B, posterior cervical pedicle screw fixation model (posterior approach);Group C, combined anterior and posterior cervical pedicle screw fixation model; Group D, Novel composite anterior cervical internal fixation model. A 75 N axial compressive load and a 1.0 N·m pure moment were applied to the upper surface of the cervical spine model to simulate flexion, extension, rotation, and lateral bending movements. The intervertebral range of motion(ROM) and stress distribution of the internal fixators under different motion conditions were compared across all models. RESULTS: Compared with the normal model, the reductions in overall intervertebral ROM for each group under flexion, extension, rotation, and lateral bending were as follows:Group A, 24.04°, 23.12°, 6.24°, and 9.06°;Group B, 24.42°, 24.34°, 6.48°, and 9.20°;Group C, 25.43°, 25.29°, 7.17°, and 9.57°;Group D, 24.75°, 25.5°, 6.71°, and 9.12°. The peak stress values of the internal fixators in each group were:Group A, 53.9 MPa, 79.9 MPa, 61.4 MPa, and 80.3 MPa;Group B, 218.3 MPa, 105.4 MPa, 206.6 MPa, and 186.8 MPa;Group C, 40.8 MPa, 97.2 MPa, 47.1 MPa, and 39.4 MPa;Group D, 93.0 MPa, 144.0 MPa, 64.8 MPa, and 106.3 MPa. CONCLUSION The biomechanical properties of the novel composite anterior cervical internal fixation method are similar to those of the combined anterior-posterior fixation method, and superior to both the anterior cervical ACLP plate-screw fixation and posterior cervical pedicle screw fixation methods.
Humans ; Finite Element Analysis ; Cervical Vertebrae/physiopathology* ; Male ; Biomechanical Phenomena ; Adult ; Fracture Fixation, Internal/methods* ; Range of Motion, Articular

Objective: To expore the correlation between neck disability, neck pain and muscle strength in cervical pondylosis of office worker, and to provide scientific basis for the prevention and treatment of cervical spondylosis. Methods: In April 2021 ,234 patients with cervical spondylotic myelopathy treated in the Subsidiary Rehabilitation Hospital of Fujian University of Traditional Chinese Medicine from April 2015 to April 2017 were selected, the correlation between Neck Disability Index (NDI) score, neck pain and muscle strength was analyzed using the Spearman rank correlation method. Mann-Whitney U test was used to compare the difference of maximum muscle strength of isometric contraction. Results: NDI score was negatively correlated with neck flexion, extension, and muscle strength in the left and right flexion directions (r(s)=-0.164, -0.169, -0.222, -0.176, P=0.012, 0.010, 0.001 , 0.007). In mild and moderate functional disorder patients, the muscle strength in flexion, extension and left and right flexion direction was greater, the difference was statistically significant (P <0.01). Conclusion: There is a negative correlation between cervical functional disorder and cervical muscle strength in office workers, suggesting that strengthening cervical muscle strength may be a way to improve cervical spine function.
Cervical Vertebrae ; Humans ; Muscle Strength/physiology* ; Neck Muscles/physiology* ; Neck Pain/physiopathology* ; Occupational Diseases/physiopathology* ; Range of Motion, Articular/physiology* ; Spondylosis/physiopathology*

OBJECTIVE: The purpose of the study is to investigate the relationship between dental calcification stages (DCS) and cervical vertebral maturation stages (CVMS) in patients with unilateral complete cleft lips and palates (UCLP) and to provide a theoretical basis for the treatment time selection of cleft lip and palate (CLP) patients. METHODS: A total of 123 UCLP patients and 215 non-CLP subjects were selected. The DCS of the left mandibular canine, premolar, and second molar in non-CLP subjects and on both cleft sides of UCLP patients were assessed utilizing the Demirjian method. CVMS was observed utilizing the Baccetti method. The results were analyzed by Spearman rank correlation, and the correlation coefficients were compared. RESULTS: There was a correlation between the CVMS and the DCS of the left mandibular canine, the first premolar, the second premolar, and the second molar in the non-CLP subjects and on both cleft sides of the UCLP patients (r=0.762-0.864, P<0.05; r=0.809-0.914, P<0.05, respectively). The correlation between the CVMS and the DCS of the mandibular first premolar was highest among the UCLP patients. Except for the first and the second premolars of UCLP females, the correlation between the DCS and the CVMS of the other teeth did not differ among the non-CLP subjects (P>0.05). CONCLUSIONS DCS can be utilized as a biological index to determine the growth development statuses. The correlation between the CVMS and the DCS of the mandibular first premolar was the highest.
Bicuspid ; Calcinosis ; Cervical Vertebrae ; pathology ; Cleft Lip ; physiopathology ; Cleft Palate ; physiopathology ; Cuspid ; Female ; Humans