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Objective:To investigate the clinical significance of a new classification system for atlas fractures based on pre- and post-treatment CT features, with a focus on diagnosis and treatment.Methods:A retrospective analysis was conducted on 75 cases of cervical vertebra fractures treated at the Sixth Hospital of Ningbo City between January 2015 and December 2020. The study included 44 males and 31 females, with an average age of 53.3±13.0 years (range: 27-81 years). The fractures were classified according to the Landells classification, resulting in 12 cases of type I, 13 cases of type II, 33 cases of type III, 9 cases that were difficult to classify due to fracture lines located at anatomical junctions, and 8 cases that could not be classified using the Landells classification due to diverse injury mechanisms. To establish a new preliminary classification for cervical vertebra fractures, the researchers considered whether the fracture line in the CT images involved the facet joint surface of the atlas, the impact on bilateral half-rings, and the displacement distance of the fracture ends. Five spinal surgeons were randomly selected to classify the CT images of the 75 patients using the new classification method. After one month, the imaging data of the 75 cases of cervical vertebra fractures were randomized and reclassified to assess the reliability and repeatability of the classification.Results:The new cervical vertebra fracture classification method comprised three types based on whether the fracture line involved the facet joint surface of the atlas: type A (no involvement of the facet joint surface of the atlas), type B (involvement of one side of the facet joint surface with intact contralateral half-ring), and type C (involvement of one side of the facet joint surface with fractured contralateral half-ring). Additionally, based on the maximum displacement distance between the fracture ends (>4 mm), six subtypes were identified: subtype 1 (≤4 mm displacement) and subtype 2 (>4 mm displacement). Consequently, the subtypes were classified as A1, A2, B1, B2, C1, and C2. According to the new classification method, the 75 patients included 17 cases of A1, 12 cases of A2, 7 cases of B1, 13 cases of B2, 12 cases of C1, and 14 cases of C2. The classification demonstrated excellent consistency, as assessed by the five doctors, with Kappa values of 0.85 and 0.91 for reliability and repeatability, respectively. At the final follow-up, all conservatively treated patients achieved bone healing, while four surgically treated patients experienced non-union of the fracture ends but exhibited good fusion between the atlas and axis. The remaining surgically treated patients achieved bony union without complications such as loosening or fracture of internal fixation.Conclusion:The new cervical vertebra fracture classification method, based on CT imaging features, comprehensively covers common clinical cases of cervical vertebra fractures and demonstrates excellent consistency. It provides valuable clinical guidance for the diagnosis and treatment of cervical vertebra fractures.
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Objective:To compare the therapeutic results between axis pedicle screwing assisted by intraoperative 3-D navigation and freehand axis pedicle screwing in the treatment of Hangman fracture.Methods:A retrospective analysis was performed of the 64 patients with Hangman fracture who had received posterior axis pedicle screwing at Department of Spinal Surgery, The Sixth Hospital of Ningbo from May 2014 to December 2019. According to the placement methods of axis pedicle screws, they were divided into a navigation group ( n=34, subjected to axis pedicle screwing assisted by intraoperative 3-D navigation) and a freehand group ( n=30, subjected to freehand axis pedicle screwing). Pedicle screw placement time, operation time, intraoperative bleeding, fluoroscopy time, hospital stay, total hospitalization cost and complications were recorded and compared between the 2 groups. The accuracy of axis pedicle screw placement was evaluated according to the postoperative cervical CT and screw grading criteria proposed by Park et al. At admission, 3 months postoperation, and the last follow-up, neurological function of the patients was evaluated by modified Japanese Orthopedic Association (mJOA) score, neck pain was evaluated by visual analogue scale (VAS), and C2/3 vertebral body angulation and C2 forward displacement were measured. The clinical efficacy was evaluated by Moon grading at the last follow-up. Results:The navigation group and the freehand group were comparable due to insignificant differences between them in the preoperative general data ( P>0.05). The accuracy of screw placement in the navigation group (98.2%, 54/55) was significantly higher than that in the freehand group (85.2%, 46/54) ( P<0.05). The screw placement time, operation time, fluoroscopy time and total hospitalization cost in the navigation group were significantly more than those in the freehand group ( P<0.05). Vertebral artery injury occurred in 3 cases in the freehand group. Screw loosening, screw breakage or rod breakage occurred in none of the patients after operation. There was no significant difference between the 2 groups in the intraoperative bleeding, hospital stay or follow-up time ( P>0.05). In both groups, the VAS score, mJOA score, C2/3 vertebral body angulation and C2 forward displacement were significantly improved at 3 months postoperation and the last follow-up compared with those at admission ( P<0.05), but there was no significant difference between the 2 groups in the contemporary comparisons ( P>0.05). At the last follow-up, Moon grading in the navigation group was significantly better than that in the freehand group ( P<0.05). Conclusion:In the treatment of Hangman fracture, compared with freehand screw placement, axis pedicle screwing assisted by intraoperative 3-D navigation can improve accuracy and safety of screw placement and reduce postoperative complications, leading to better clinical efficacy.
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Objective:To investigate the anatomical safety and feasibility ofposterior occipitocervical fixation with atlan-tooccipital-clivus screw.Methods:Data of 60 patients who treated in the spinal department of our hospital with upper cervical computed tomographic scans from February 2017 to November 2019 were retrospectively collected. Occipitocervical infection, injury, tumor and deformity were excluded. The Mimics software was used to reconstruct the occiput, atlas and measure the anatomical parameters, including the height and width of the anterior edge of the clivus, the height and width of the middle part of the clivus, the thinnest distance of the soft tissue in front of the clivus, the anteroposterior diameter, transverse diameter, the angle of inside tilting in coronary plane of the occipital condyle, the distance from the hypoglossal canal to the atlantooccipital articular surface, the anteroposterior diameter and transverse diameter of the superior joint of atlas, the height of the lateral mass, and the height and transverse diameter of the inferior articular process of the superior atlas joint. The three-dimensional digital modeling was performed and the screw diameter of 3.5mm was simulated. 3-Matic software were used to measure the screw placement parameters, including the inside tilting angle in coronary plane of screw, and the angle of upper tilting in sagittal plane and length of screw. The atlanto-occipital junction was exposed at the rear of 8 cadavers. According to the above parameters, the titanium alloy screws with a diameter of 3.5 mm were transferred from the inferior articular process and posterior arch of the atlas to the clivus through the atlantooccipital. Finally, the screw path was cut along the nail path with a pendulum saw, and the track of the screw was observed to confirm the safety and effectiveness of the screw.Results:The leading edge height and width of male clivus was 16.8±2.5 mm and 20.1±3.1 mm. The middle part of the clivus was 9.7±2.3 mm and 22.4±3.7 mm. The thinnest soft tissue in front of the clivus was 5.8±1.48 mm. The anteroposterior diameter of the occipital condyle was 19.1±1.9 mm, the transverse diameter was 12.6±2.0 mm, the inside tilting angle was 33.7°±4.5°, and the vertical distance from the lowest point of the neural tube to the articular surface of the occipital condyle was 9.6±1.1 mm. The height of the lateral mass of atlas was 12.9±2.4 mm, the anteroposterior diameter of the upper joint of atlas was 21.7±1.9 mm, and the transverse diameter was 11.7±1.4 mm. The width of the inferior facet was 14.9±1.4 mm and the height of the inferior facet was 5.7±0.85 mm. The distance from the screw entry point to the vertical line of the lateral mass migration midpoint was 2.5±0.6 mm; The distance from the screw entry point to the horizontal line of the midpoint was 2.3±0.7 mm.The inside titling angle of screw was 18.4°±1.6°, the upper tilting angle was 55.6°±3.1°, the length of the screw track was 53.0±2.8 mm, the adjustment range of upper tilting angle was 15.0±2.8 mm, the adjustment range of inside tilting angle was 10.4±2.4 mm. The anatomical parameters of females were slightly smaller than those of males, and the difference was statistically significant, but there was no significant difference between left and right parameters. The screws of 8 specimens could be inserted safely and effectively.Conclusion:Atlan-tooccipital-clivus screw can be implanted without damaging the nerve and vascular structure, and it can be used as a choice for occipitocervical fixation.
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AIM: To study the mechanism of resveratrol inhibiting NLRP3 inflammasome activation in rabbits with spinal cord injury. METHODS: Fifty male Japanese big ear rabbits were randomly divided into 5 groups: blank control group (CON group), spinal cord injury model group (SCI group), low-dose resveratrol group (RSV(L) group), and resveratrol high-dose group (RSV(H) group), methylprednisolone group (MP group), 10 rabbits in each group. Spinal cord injury models were prepared in all four groups except the CON group. All groups received iv administration daily, and the same amount of normal saline was given to the CON group and the SCI group for 14 consecutive days. The Tarlov method was used to evaluate the neurobehavioral score in rabbits. The chromogenic substrate method was used to determine the MDA content and the activity of SOD and GSH-Px in spinal cord tissues. Western blot was used to determine the proteins expression of NLRP3, Caspase1 p20, IL-1β, Sirt1, NF-κB p65 in spinal cord neural tissues, HE staining to observe the pathological changes of spinal cord tissue. RESULTS: Resveratrol increased the behavioral score of spinal cord injury rabbits, promoted the repair of injured tissues, reduced the MDA content, increased the activity of SOD and GSH-Px in spinal cord tissues, down-regulated the expression of NF-κB p65, up-regulated the expression of Sirt1 in spinal cord tissues, and inhibited expression of NLRP3 in inflammasome (reduction in expression of NLRP3, Caspase1 p20, and IL-1β in spinal cord tissues). CONCLUSION: Resveratrol can promote the recovery of spinal cord injury rabbits, and its mechanism may play a role by activating Sirt1, regulating NF-κB pathway and antioxidant level in vivo, and further inhibiting the activation of NLRP3 inflammasome.
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Objective:To investigate the efficacy of screw-rod fixation and fusion in revision surgery after percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty(PKP) for osteoporotic vertebral fractures (OVFs).Methods:A retrospective case series study was carried out on clinical data of 19 patients treated by revision surgery after PVP or PKP at Zhejiang Ningbo No.6 Hospital from January 2014 to December 2017. There were 5 males and 14 females, with age of (70.7±6.0)years (range, 58-81 years). Injured segment was located at T 9 in 1 patient, T 11 in 3, T 12 in 5, L 1 fracture in 5, L 2 in 2, L 3 in 2 and L 4 in 1. Caused for revision and operation methods were as follows, 5 patients underwent debridement, screw-rod fixation and fusion due to infection, 9 patients underwent osteotomy due to progressive kyphosis, screw-rod fixation and fusion, 5 patients underwent spinal canal decompression, screw-rod fixation and fusion due to neurological dysfunction. The operation time, intraoperative blood loss, and perioperative complications were recorded. The white blood cell (WBC), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were used to evaluate the control of infection before operation, before discharge and at postoperative 3 months. The changes in Cobb angle were measured before and after operation and at the final follow-up. The American spinal injury association (ASIA) scale, visual analog scale (VAS) and Oswestry disability index (ODI) were evaluated at the final follow-up. Results:All patients were followed up for 24-46 months [(32.7±8.3)months]. The revision operation time was 135-320 minutes [(226.3±75.6)minutes]. The intraoperative blood loss was 350-1 500 ml [(825.5±230.6)ml]. There were 1 patient with poor wound healing, 2 with pulmonary infection, and 2 with hardware loosening. The WBC, ESR and CRP decreased from preoperative (9.2±1.7)×10 9/L, (88.7±19.2)mm/h, (58.7±22.9)mg/L to (7.3±0.9)×10 9/L, (42.5±13.7)mm/h, (37.3±16.3)mg/L before discharge, and (6.6±0.7)×10 9/L, (26.8±9.5)mm/h, (17.8±8.6)mg/L at postoperative 3 months ( P<0.01). The Cobb angle improved from preoperative (29.3±5.2)° to (4.8±1.2)° ofter operation and (7.3±1.6)° at the final follow-up ( P<0.05). The patients with ASIA grade C ( n=2) and grade D ( n=1) improved to grade E, and the patients with ASIA grade C ( n=2) improved to grade D at the final follow-up. Imagines showed good bone fusion in all patients at the last follow-up. The mean VAS decreased from preoperative (7.5±0.8)points to (2.1±0.5)points at the last follow-up ( P<0.05). The ODI decreased from preoperative (60.7±15.2)% to (19.9±5.9)% at the last follow-up ( P<0.05). Conclusion:For patients with OVFs undergoing revision surgery after PVP or PKP, debridement, kyphosis correction, spinal canal decompression combined with screw-rod fixation and fusion can reduce infection, correct kyphotic deformity, improve neurological function, relieve pain and improve quality of life.
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Objective:To investigate the safety of posterior atlantoaxial transarticular screw combined with atlas pedicle screw fixation in Chinese.Methods:CT data of upper cervical spine in 48 patients were collected from Ningbo No.6 Hospital, including 26 males and 22 females aged 26-58 years [(37.3±13.5)years]. All CT data was transformed into 3D dimensional model and inserted with virtual screws by Mimics 19.0. Firstly, the vertical plane P 1 and the horizontal plane P 2 of the atlas were built in those atlantoaxial models, secondly the atlantoaxial transarticular screw S 0 was inserted by Margel method, and it's insertion point was located at 3 mm lateral and 2 mm cephalad in the C 2 inferior articular process. Finally, four atlas pedicle screws were inserted at the midline of atlas lateral mass. The four screws are inserted as follows. S 1: the screw was tangent to the lateral side of the S 0 or the medial of the atlas pedicle. S 2: the screw was tangent to the lateral wall of the atlas pedicle. S 3: the screw was tangent to the upper wall of the atlas pedicle. S 4: the screw was tangent to the inferior wall of the atlas pedicle. The angles between S 1, S 2 and P 1 as the camber angle, and the angle between S 3, S 4 and P 2 as the gantry angle were measured. Then the safety range of camber angle and gantry angle were calculated, and the screw length of S 1, S 2, S 3 and S 4 was measured. In all models, the camber angle and gantry angle of the screws were adjusted an interval of 2°, the number of successful cases was calculated and the success rate of insertion was calculated. Results:All 3D models were inserted successfully. The minimum value, maximum value and safety range of the camber angle of atlas pedicle screws were (-6.7±5.2)°, (10.4± 4.3)°, (17.1±3.7)°, respectively; and of the gantry angle were (-0.5±3.5)°, (11.0±5.8)°, (11.5±4.9)°, respectively. The length of screw placement was S 1: (31.1±2.4)mm, S 2: (28.3±2.5)mm, S 3: (29.2±3.8)mm, S 4: (29.6±3.0)mm, respectively ( P<0.05). When the camber angle was from -1°to 5°, the success rate of screw placement was 87.5%; when inserting with 2° camber angle, the success rate was 100%; when the gantry angle was 5°, the success rate was 93.8%. Conclusion:The posterior atlantoaxial transarticular screw combined with atlas pedicle screw can achieve satisfy insertion length and success rate.
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Objective@#To investigate the efficacy of microscope-assisted free-hand atlantal pedicle screw technique for unstable atlas burst fracture.@*Methods@#A retrospective case control study was conducted to analyze the clinical data of 48 patients with unstable atlas burst fracture admitted to Ningbo No.6 hospital from January 2016 to June 2018. There were 32 males and 16 females, aged 24-72 years [(49.5±15.2 years)]. A total of 22 patients were treated with the technique of atlas screw placement by drill under microscope (Group A), including 14 males and eight females, aged 24-68 years. Twenty six patients (Group B) were treated with atlantal pedicle screw placement by hand, including 18 males and 8 females, aged 26-72 years [(50.7±15.4 years)]. The operation time, intraoperative blood loss and the times of intraoperative fluoroscopy were compared between the two groups. X-ray and CT were reexamined to evaluate the accuracy of screw placement within one week after operation. The visual analogue score (VAS) and cervical dysfunction index (NDI) were compared before operation and 1 year after operation. The intraoperative complications were recorded. One year after operation, X-ray and CT were reexamined to observe fracture healing, atlantoaxial fusion and failure of internal fixation.@*Results@#Group A was followed up for 12-24 months [(18.4±6.8)months], and Group B for 12-24 months [(17.4±7.2)months]. The amount of intraoperative bleeding [(180.5±60.8) ml] and the times of intraoperative fluoroscopy [(1.3±0.8) times] in Group A were significantly lower than those in Group B [(280.1±80.2) ml, (2.2±0.8) times] (P<0.05), but there was no significant difference in the time of operation and the accuracy of screw placement (P>0.05). There were statistically significant differences in VAS and NDI before operation and one year after operation in both groups (P<0.05), but there was no significant difference between the two groups (P>0.05). No serious complications such as vertebral artery, nerve root and spinal cord injury occurred. One year follow-up CT showed healed fracture or continuous bone bridge passing through the atlantoaxial intervertebral space. Except for one patient in Group B with lost reduction, other patients had no loosening or fracture of internal fixation.@*Conclusion@#Compared with screw placement by hand, the pedicle screw placement by drill under the microscope can reduce the amount of bleeding and the times of fluoroscopy.
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Objective@#To investigate the accuracy and feasibility of individual 3D printing model for pedicle screw placement in treating patients with upper cervical spine fracture.@*Methods@#A retrospective case control study was conducted to analyze the clinical data of 30 patients with upper cervical spine fracture admitted to Ningbo No.6 Hospital from August 2013 to December 2018. There were 19 males and 11 females, aged 45-67 years with an average age of 53.5 years. The 15 patients in the study group were treated with pedicle screw fixation and another 15 patients in the control group were treated with traditional freehand screw fixation. A total of 120 pedicle screws were implanted, with 60 screws in each group. The operation time, intraoperative blood loss, preoperative and postoperative visual analogue score (VAS), Japan Orthopedic Association (JOA) score were recorded. The position and grade of screws were evaluated according to Kawaguchi's evaluation method of screw grade after operation. The patients took monthly reexamination for the first three months after discharge. In the first two months after discharge, the patients took X-ray examination for observation of screw loosening or rupture of internal fixation. At the third month after operation, the patients took CT of cervical spine for observation of bone healing and fusion.@*Results@#The mean follow-up duration was 17.8 months (range, 13-21 months). The study group had shorter operation time (99.13±3.04)minutes compared with the control group (107.00±6.92) minutes (P<0.01). There were no significant differences in intraoperative blood loss, preoperative VAS, JOA scores before operation and 1 year after operation between the two groups (P>0.05), but the VAS in study group was significantly lower than that in control group (P<0.05). In the study group, the VAS score 1 year after operation [(2.3±0.5)points] was lower than that before the operation [(7.7±0.7)points], and the JOA score [(16.8±0.4)points] was significantly higher than that before the operation [(15.9±0.7)points](P<0.01). In the control group, the VAS 1 year after operation [(2.5±0.5)points] was significantly lower than that before operation [(7.5±0.5)points] (P<0.01), and the JOA score [(16.5±0.5)points] was significantly higher than that before operation [(15.9±0.8)points] (P<0.05). In the study group, according to the CT results, there were 28 atlas pedicle screws of grade 0 (93.3%), two of grade 1 (6.7%), 0 of grade 2, 0 of grade 3, and there were 27 axial pedicle screws of grade 0 (90.0%), three of grade 1 (10.0%), 0 of grade 2, and 0 of grade 3. In the control group, there were 25 atlas pedicle screws of grade 0 (83.3%), four of grade 1 (13.3%), one of grade 2 (3.4%), 0 of grade 3, and there were 27 axial pedical screws of grade 0 (90.0%), three of grade 1 (10.0%), 0 of grade 2, and 0 of grade 3. There was no significant difference in the accuracy of pedicle screw placement between the two groups (P>0.05). No serious complications such as spinal cord or vertebral artery injury occurred. At 3 months after operation, CT showed that the fracture of cervical vertebra healed.@*Conclusion@#Individualized 3D printed cervical spine model can guide the pedicle screw placement for upper cervical spine fracture, which can shorten the operation time, reduce the postoperative pain of patients, improve the accuracy of screw placement, and reduce the risks related to operation.
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Objective@#To compare the clinical efficacy of posterior atlantoaxial screw-rod fixation combined with spinous process muscle-vessel complex bone graft or iliac bone graft for atlantoaxial instability.@*Methods@#A retrospective case-control study was conducted to analyze the clinical data of 56 patients with atlantoaxial instability admitted to the Sixth Hospital of Ningbo from September 2014 to October 2016. There were 35 males and 21 females, with the age range from 9 to 59 years [(50.3±3.2)years]. A total of 26 patients were treated with posterior atlantoaxial screw-rod fixation combined with spinous process muscle-vessel complex bone graft (complex group), while 30 patients were treated with iliac bone graft (ilium group). Patients showed different degrees of neck pain and limited neck activity preoperatively. X-ray films and three-dimensional CT examination of the cervical spine were taken before and after operation for evaluating the atlantoaxial reduction, bone graft fusion and internal fixation. The operation time, intraoperative bleeding, bone fusion time, visual analogue scale (VAS), Japanese Orthopaedic Association (JOA) score, atlantodental interval (ADI) and axial symptoms were compared between the two groups, and the complications were recorded.@*Results@#Both groups were followed up for 24-30 months, with an average of 27.4 months. In the complex group and the ilium group, the operation time was (2.21±0.25)hours and (2.72±0.26)hours (P<0.01); the intraoperative blood loss was (227.3±45.4)ml and (277.7±43.4)ml, respectively (P<0.05); the bone fusion time was (6.9±0.5)months and (8.1±1.8)months (P>0.05), respectively. In the complex group, the VAS was (5.45±0.69)points before operation, (2.64±0.51)points at the follow-up one month after operation, (0.91±0.7)points at the follow-up 12 months after operation, and (0.45±0.16)points at the follow-up 24 months after operation; and in the ilium group, the VAS was (5.18±0.75)points, (2.45±0.52)points, (1.27±0.19)points and (0.41±0.18)points correspondingly. In terms of VAS, there were significant differences before and after operation within each group (P<0.01), while there were no significant differences between the two groups at different time points (P>0.05). In the complex group, the JOA score was (10.82±0.35)points before operation, (12.73±0.65)points at the follow-up one month after operation, (15.18±0.61)points at the follow-up 12 months after operation, and (15.64±0.15)points at the follow-up 24 months after operation; and in the ilium group, the JOA score was (10.73±1.19)points, (13.01±0.63)points, (14.73±0.91)points and (15.55±0.51)points correspondingly. In terms of JOA score, there were significant differences between before and after operation within each group (P<0.01), while there were no significant differences between the two groups at different time points (P>0.05). In the complex group, the ADI was (2.28±0.59)mm before operation, (1.83±0.56)mm at the follow-up one month after operation, (1.71±0.56)mm at the follow-up 12 months after operation, and (1.59±0.67)mm at the follow-up 24 months after operation; and in the ilium group, the ADI was (2.23±0.60)mm, (1.80±0.18)mm, (1.67±0.69)mm and (1.62±0.53)mm correspondingly. In terms of ADI, there were significant differences between before and after operation within each group (P<0.01), while there were no significant differences between the two groups at different time points (P>0.05). The axial symptom scores were graded as excellent in 23 patients and good in three patients of the complex group while excellent in 21 patients and good in nine patients in the ilium group (P>0.05). There were no patients with spinal nerve injury caused by pedicle screw placement after operation. One patient in the ilium group had incision errhysis and recovered after dressing change, and other patients had no incision infection.@*Conclusions@#For atlantoaxial instability, posterior atlantoaxial screw-rod fixation combined with spinous process muscle-vessel complex bone graft or autogenous iliac bone graft can both achieve satisfactory clinical results. The spinous process-muscle-vascellum complex graft has less operation time and intraoperative bleeding than the autogenous iliac bone graft, which can be a feasible alternative operation.
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Objective To compare the clinical efficacy of posterior atlantoaxial screw-rod fixation combined with spinous process muscle-vessel complex bone graft or iliac bone graft for atlantoaxial instability.Methods A retrospective case-control study was conducted to analyze the clinical data of 56 patients with atlantoaxial instability admitted to the Sixth Hospital of Ningbo from September 2014 to October 2016.There were 35 males and 21 females,with the age range from 9 to 59 years [(50.3 ±3.2) years].A total of 26 patients were treated with posterior atlantoaxial screw-rod fixation combined with spinous process muscle-vessel complex bone graft (complex group),while 30 patients were treated with iliac bone graft (ilium group).Patients showed different degrees of neck pain and limited neck activity preoperatively.X-ray films and three-dimensional CT examination of the cervical spine were taken before and after operation for evaluating the atlantoaxial reduction,bone graft fusion and internal fixation.The operation time,intraoperative bleeding,bone fusion time,visual analogue scale (VAS),Japanese Orthopaedic Association (JOA) score,atlantodental interval (ADI) and axial symptoms were compared between the two groups,and the complications were recorded.Results Both groups were followed up for 24-30 months,with an average of 27.4 months.In the complex group and the ilium group,the operation time was (2.21 ±0.25) hours and (2.72 ±0.26) hours (P ＜0.01);the intraoperative blood loss was (227.3 ± 45.4) ml and (277.7 ± 43.4) ml,respectively (P ＜ 0.05);the bone fusion time was (6.9 ±0.5) months and (8.1 ± 1.8) months (P ＞ 0.05),respectively.In the complex group,the VAS was (5.45 ± 0.69)points before operation,(2.64 ± 0.51)points at the follow-up one month after operation,(0.91 ± 0.7) points at the follow-up 12 months after operation,and (0.45 ± 0.16) points at the follow-up 24 months after operation;and in the ilium group,the VAS was (5.18 ± 0.75) points,(2.45 ± 0.52)points,(1.27 ± 0.19) points and (0.41 ± 0.18) points correspondingly.In terms of VAS,there were significant differences before and after operation within each group (P ＜ 0.01),while there were no significant differences between the two groups at different time points (P ＞ 0.05).In the complex group,the JOA score was (10.82 ± 0.35) points before operation,(12.73 ± 0.65) points at the follow-up one month after operation,(15.18 ±0.61) points at the follow-up 12 months after operation,and (15.64 ±0.15) points at the follow-up 24 months after operation;and in the ilium group,the JOA score was (10.73 ± 1.19) points,(13.01 ± 0.63) points,(14.73 ± 0.91) points and (15.55 ± 0.51) points correspondingly.In terms of JOA score,there were significant differences between before and after operation within each group (P ＜ 0.01),while there were no significant differences between the two groups at different time points (P ＞ 0.05).In the complex group,the ADI was (2.28 ± 0.59) mm before operation,(1.83 ± 0.56)mm at the follow-up one month after operation,(1.71 ± 0.56)mm at the follow-up 12 months after operation,and (1.59 ± 0.67)mm at the follow-up 24 months after operation;and in the ilium group,the ADI was (2.23 ± 0.60) mm,(1.80 ± 0.18) mm,(1.67 ± 0.69) mm and (1.62 ± 0.53) mm correspondingly.In terms of ADI,there were significant differences between before and after operation within each group (P ＜ 0.01),while there were no significant differences between the two groups at different time points (P ＞ 0.05).The axial symptom scores were graded as excellent in 23 patients and good in three patients of the complex group while excellent in 21 patients and good in nine patients in the ilium group (P ＞ 0.05).There were no patients with spinal nerve injury caused by pedicle screw placement after operation.One patient in the ilium group had incision errhysis and recovered after dressing change,and other patients had no incision infection.Conclusions For atlantoaxial instability,posterior atlantoaxial screw-rod fixation combined with spinous process muscle-vessel complex bone graft or autogenous iliac bone graft can both achieve satisfactory clinical results.The spinous process-muscle-vascellum complex graft has less operation time and intraoperative bleeding than the autogenous iliac bone graft,which can be a feasible alternative operation.
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Objective To investigate the efficacy of microscope-assisted free-hand atlantal pedicle screw technique for unstable atlas burst fracture.Methods A retrospective case control study was conducted to analyze the clinical data of 48 patients with unstable atlas burst fracture admitted to Ningbo No.6 hospital from January 2016 to June 2018.There were 32 males and 16 females,aged 24-72 years [(49.5 ± 15.2 years)].A total of 22 patients were treated with the technique of atlas screw placement by drill under microscope (Group A),including 14 males and eight females,aged 24-68 years.Twenty six patients (Group B) were treated with atlantal pedicle screw placement by hand,including 18 males and 8 females,aged 26-72 years [(50.7 ± 15.4 years)].The operation time,intraoperative blood loss and the times of intraoperative fluoroscopy were compared between the two groups.X-ray and CT were reexamined to evaluate the accuracy of screw placement within one week after operation.The visual analogue score (VAS) and cervical dysfunction index (NDI) were compared before operation and 1 year after operation.The intraoperative complications were recorded.One year after operation,X-ray and CT were reexamined to observe fracture healing,aflantoaxial fusion and failure of internal fixation.Results Group A was followed up for 12-24 months [(18.4 ± 6.8)months],and Group B for 12-24 months [(17.4 ± 7.2) months].The amount of intraoperative bleeding [(180.5 ±60.8) ml] and the times of intraoperative fluoroscopy [(1.3 ±0.8) times] in Group A were significantly lower than those in Group B [(280.1 ± 80.2) ml,(2.2 ± 0.8) times] (P ＜ 0.05),but there was no significant difference in the time of operation and the accuracy of screw placement (P ＞ 0.05).There were statistically significant differences in VAS and NDI before operation and one year after operation in both groups (P ＜ 0.05),but there was no significant difference between the two groups (P ＞ 0.05).No serious complications such as vertebral artery,nerve root and spinal cord injury occurred.One year follow-up CT showed healed fracture or continuous bone bridge passing through the atlantoaxial intervertebral space.Except for one patient in Group B with lost reduction,other patients had no loosening or fracture of internal fixation.Conclusion Compared with screw placement by hand,the pedicle screw placement by drill under the microscope can reduce the amount of bleeding and the times of fluoroscopy.
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Objective To investigate the accuracy and feasibility of individual 3D printing model for pedicle screw placement in treating patients with upper cervical spine fracture.Methods A retrospective case control study was conducted to analyze the clinical data of 30 patients with upper cervical spine fracture admitted to Ningbo No.6 Hospital from August 2013 to December 2018.There were 19 males and 11 females,aged 45-67 years with an average age of 53.5 years.The 15 patients in the study group were treated with pedicle screw fixation and another 15 patients in the control group were treated with traditional freehand screw fixation.A total of 120 pedicle screws were implanted,with 60 screws in each group.The operation time,intraoperative blood loss,preoperative and postoperative visual analogue score (VAS),Japan Orthopedic Association (JOA) score were recorded.The position and grade of screws were evaluated according to Kawaguchi's evaluation method of screw grade after operation.The patients took monthly reexamination for the first three months after discharge.In the first two months after discharge,the patients took X-ray examination for observation of screw loosening or rupture of internal fixation.At the third month after operation,the patients took CT of cervical spine for observation of bone healing and fusion.Results The mean follow-up duration was 17.8 months (range,13-21 months).The study group had shorter operation time (99.13 ± 3.04)minutes compared with the control group (107.00 ± 6.92) minutes (P ＜ 0.01).There were no significant differences in intraoperative blood loss,preoperative VAS,JOA scores before operation and 1 year after operation between the two groups (P ＞ 0.05),but the VAS in study group was significantly lower than that in control group (P ＜ 0.05).In the study group,the VAS score 1 year after operation [(2.3 ± 0.5) points] was lower than that before the operation [(7.7 ± 0.7) points],and the JOA score [(16.8 ± 0.4) points] was significantly higher than that before the operation [(15.9 ± 0.7) points] (P ＜ 0.01).In the control group,the VAS 1 year after operation [(2.5 ± 0.5) points] was significantly lower than that before operation [(7.5 ±0.5)points] (P ＜0.01),and the JOA score [(16.5 ±0.5)points] was significantly higher than that before operation [(15.9 ± 0.8)points] (P ＜ 0.05).In the study group,according to the CT results,there were 28 atlas pedicle screws of grade 0 (93.3％),two of grade 1 (6.7％),0 of grade 2,0 of grade 3,and there were 27 axial pedicle screws of grade 0 (90.0％),three of grade 1 (10.0％),0 of grade 2,and 0 of grade 3.In the control group,there were 25 atlas pedicle screws of grade 0 (83.3％),four of grade 1 (13.3％),one of grade 2 (3.4％),0 of grade 3,and there were 27 axial pedical screws of grade 0 (90.0％),three of grade 1 (10.0％),0 of grade 2,and 0 of grade 3.There was no significant difference in the accuracy of pedicle screw placement between the two groups (P ＞ 0.05).No serious complications such as spinal cord or vertebral artery injury occurred.At 3 months after operation,CT showed that the fracture of cervical vertebra healed.Conclusion Individualized 3D printed cervical spine model can guide the pedicle screw placement for upper cervical spine fracture,which can shorten the operation time,reduce the postoperative pain of patients,improve the accuracy of screw placement,and reduce the risks related to operation.
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Objective To assess the effects of axial spinous process-muscle-vascellum complex transplantation for posterior atlantoarial fusion.Methods Data of 27 cases with altantoarial disease who were treated by posterior atlantoarial fusion using axial spinous process-muscle-vascellum complex transplantation from June 2015 to June 2016 were retrospectively analyzed.There were 19 males and 8 females aged from 9 to 68 years old (mean,41.0±15.4 years old).Two cases were diagnosed with atlanto-axial instability.Fourteen cases were diagnosed with atlas fracture and eleven cases were diagnosed atlanto-axial fracture.All the 27 patients suffered from neck pain or limitations of cervical motion.All patients were assessed clinically by atlantoaxial reduction and bone graft fusion.The pre-operative and post-operative atlanto-dens interval (ADI),visual analogue scale (VAS),Japanese Orthopaedic Association scores (JOA),improvement rate of JOA score and axial symptoms were measured and statistically analyzed.Complications were recorded.Clinical outcome of latest follow-up was evaluated by X-ray and CT scan.Results The time of operation was 2.0-2.5 h and blood loss was 150-300 ml.All the patients were followed-up for 9 to 18 months (mean,11.5±2.1 months).The VAS of neck pain improved from 3.6±2.7 (range,2.0-5.0) pre-operatively to 1.4±0.2 (range,0-2.0) 12 months postoperatively (P=0.000).The JOA score improved from 11.7± 1.9 (range,10.0-15.0) pre-operatively to 15.3±0.6 (range,14.0-17.0)12 months post-operatively (P=0.000).The improvement rate of JOA score at the latest follow-up was 54.1％± 12.4％,including 23 cases (85.19％) excellent,and 4 cases (14.81％) good.The results of axial symptoms were no-symptom in 22 cases (81.48％) and mild symptoms in 5 cases (18.52％).Postoperative cervical spine X-ray and CT showed that the sagittal cervical spine alignment was restored.There was statistically significant difference between ADI of 4.3±1.1 mm (range,3.9-4.5 mm) pre-operatively to 2.5± 0.4 mm (range,2.1-2.6 mm) 12 months post-operatively,which was improved significantly (P=0.000).There were no complications found during the follow-up.Conclusion The application of axial spinous process-muscle-vascellum complex transplantation for posterior atlantoaxial fixation can preserve the dynamic function of muscles and reduce the postoperative pain,as well as avoid donor site morbidity.
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Objective To evaluate the efficacy of proximal percutaneous pedicle screw fixation combined with distal open osteotomy for sagittal plane imbalance of adult spinal deformity.Methods From January 2011 to June 2015,23 patients with diagnosis of adult spinal deformity were treated with proximal percutaneous pedicle screw fixation combined with distal open osteotomy,there were 8 males and 15 females,aged from 52 to 67 years old (average,62.1 years old).The operation time,blood loss,drainage and perioperative complications were recorded;standing anteroposterior and lateral radiographs of the whole spine were taken and the following parameters were measured:sagittal vertical axis (SVA),lumbar lordosis(LL),pelvic tilt (PT),sacral slope (SS),pelvic incidence/lumbar lordosis mismatch (PI-LL),the above parameters were compared between preoperation and postoperation.Oswestry disability index (ODI) was used to evaluate the clinical efficacy.Results The mean operation time was 253.9±52.1 min,the mean blood loss and drainage was 1 258.5±272.2 ml and 725.1 ± 135.2 ml.No patient got infected,died or had deep vein thrombosis.All patients were followed up for an average of 21.2 months (range,13-52 m).The SVA was restored from 12.6±1.4 cm to 3.5±0.7 cm.In addition,LL,SS,PT,and PL-LL were improved from 13.5°±2.3°,13.9°±2.3°,29.7°±9.6°,29.5°±13.7° to 38.8°±9.6°,25.5°±5.8°,18.9°±8.2°,7.1°±3.6°.The ODI score decreased from 40.3％±12.5％ to 13.6％±2.57％ at the time of the last follow-up compared with preoperation.Conclusion Proximal percutaneous pedicle screw fixation combined with distal open osteotomy for sagittal plane imbalance of adult spinal deformity could restore the sagittal balance and improve the quality of life.
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<p><b>OBJECTIVE</b>To evaluate the biomechanical effects of the anterior cervical transpedicular-screw system (ACTPS), compared to the anterior cervical screw plate system (ACLP), in the subaxial cervical spine after 2-level corpectomy.</p><p><b>METHODS</b>A verified intact finite element subaxial cervical (C3-C7) model was established and analyzed by Mimics 10.0, Rapidform XOR3, Hypermesh 10.0, CATIA5V19, ANSYS 14.0 softwares based on the CT data (C1-T1) was collected from a 28 years old male volunteer. The axial force of 75 N and moment couple of 1N·m was loaded on the upper surface of C3, which made the model movement in flexion extension, lateral bending, rotating direction, respectively. Then, recorded the range of motion, and compared the results with the in vitro biomechanical experimental data to verify the effectiveness of the model. The ACTPS model and the ACLP model were analyzed using the finite element method. The range of motion at the operation segments (C4-C7), the range of motion at the adjacent segment (C3-C4) and stress distribution under flexion, extension, lateral bending, and axial rotation were calculated, and compared the range of motion with intact model.</p><p><b>RESULTS</b>There were 85,832 elements and 23,612 nodes in the intact model of subaxial cervical spine (C3-C7) in this experiment,and the range of motion of intact model validated with the reported cadaveric experimental data. In ACTPS group the stress was been well-distributed, but the stress concentrated on the interface between screw and the titanium plate in ACLP group. There were obvious differences of the maximum stress value between the two groups. The range of motion of fixed segments in ACTPS group was smaller than ACLP group, however adjacent segment range of motion showed no significant difference. Compared with the intact group, the range of motion in flexion extension, lateral flexion, rotation direction was decreased respectively about 25°, 20° and 8°, the range of motion at adjacent segment (C3-C4) was correspondingly compensated about 0.3°, 3° and 0.1°.</p><p><b>CONCLUSIONS</b>ACTPS is better than ACLP in terms of biomechanical properties. It offers rigid stability, and may be more suitable for reconstruction stability of 2-level and more than 2 levels corpectomy in the subaxial cervical spine. Meanwhile, the risk of fracture of ACTPS system is lower than that of the ACLP system.</p>
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Adult , Humans , Male , Biomechanical Phenomena , Bone Screws , Cervical Vertebrae , General Surgery , Finite Element Analysis , Models, Anatomic , Range of Motion, Articular , RotationABSTRACT
Objective To investigate the preliminary clinical application of anterior pedicle screws in treatment of the lower cervical spine injuries. Methods The study involved 22 patients with lower cervical spine injuries treated with anterior pedicle screw technique from January 2009 to December 2011.X-ray and CT images of the patients were taken postoperatively to evaluate whether the position,orientation and length of the screws were appropriate and whether there involved pedicle cortex perforation,transverse foramen or spinal canal invasion.MRI was also performed to ascertain the situation of decompression,the formation of epidural hematoma and the degeneration of cervical spinal cord.The improvement of JOA score was compared statistically. Results All the patients were followed up for 3-36 months ( mean,15.5 months).A total of 44 anterior lower cervical screws were implanted and all screws were inserted smoothly.All the patients had bone healing after average 4.5 months,which showed no loosening,prolapse or breakage of the screws or no loosening of the plate.One patient showed hoarseness postoperatively,which was probably due to the long-term distraction of recurrent laryngeal nerve.The symptom disappeared at around three weeks after neurotrophic support.Two patients complained of dysphagia postoperatively,and were informed of keeping a soft diet.The symptom was remarkably alleviated after three months or so.The X-ray films indicated satisfactory position of the implanted screws.Before discharge,the transaxial CT images showed that two screws perforated the medial pedicle cortex ( 1 ° ) and that two screws perforated the lateral cortex (1 °) and affected the medial margin of the transverse foramen.Before discharge,the MRI indicated obvious alleviation of the anterior spinal cord compression in all patients and a small amount of anterior epidural hematoma in four patients,with no obvious spinal cord compression.At 12 months after operation,the MRI showed significant improvement of spinal cord degeneration in three patients.JOA score was increased from preoperative (8.5 ± 0.7) to ( 14.5 ± 0.8 ) before discharge (P ＜0.01 ).JOA score was (15.7 ±0.7) at six months postoperatively,which was significantly improved as compared with that before discharge. Conclusions Anterior pedicle screw fixation is a reliable and safe method for reconstruction of the anterior lower cervical injuries.Surgical indications should be strictly controlled in its clinical application.
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Objective To explore the clinical outcomes of anterior plate fixation through transoral approach in the treatment of unstable atlas fractures.Methods From March 2004 to May 2010,20 patients with unstable atlas fractures were treated by anterior plate fixation through transoral approach,including 12 males and 8 females,aged from 23 to 68 years (average,47.7±13.9 years).Of the 20 cases of unstable atlas fractures,4 cases were classified as anterior 1/2 Jefferson fracture,8 cases as 1/2 ring Jefferson fracture,and 8 cases as anterior 3/4 ring Jefferson fracture.The preoperative average VAS scores were 6.0±1.3 points,ranged from 4 to 8 points.Clinical and imaging examinations were performed during follow-up period to evaluate the outcomes.Results All patients were followed up for 12 to 81 months,with an average of 48.5±20.0 months.There were no screw loosing and breakage,no plate displacement,and no spinal cord and vertebral artery injury during operation.A total of 20 plates were placed and all 40 screws were inserted into atlas lateral mass.Computed tomography scans demonstrated 2 screws were placed too close to the vertebral artery canal,but without clinical consequences.The postoperative VAS scores were from 0 to 3 points with an average of 1.3±1.0 points.Static and dynamic films 6 months after surgery demonstrated that fusion was achieved in all cases.Atlantoaxial rotational function was restored satisfactorily.No plate-related complication was observed in all patients in the whole follow-up period.Conclusion Anterior plate fixation through transoral approach is an effective method for management of unstable atlas fractures,which has advantages such as solid bony fusion and low incidence of complication.
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ObjectiveTo evaluate the clinical effects of transforaminal lumbar interbody fusion (TLIF) or posterior lumbar interbody fusion(PLIF) using microendoscopic discectomy under X-Tube system in treatment of lumbar degenerative disc diseases.MethodsFrom December 2007 to April 2008,32 patients with low back disorders were treated by microendoscopic discectomy TLIF or PLIF under X-Tube system,including 19 cases in TLIF and 13 in PLIF.Etiologies including lumbar disc herniation combined with segmental instability in 21 cases,and spondylolisthesis in 11 cases.All patients were under regular postoperative follow-up and radiological examination.The clinical functional outcomes were evaluated according to Oswestry disability questionnaire.ResultsThe mean operation time was 120 min(range,90-180),and the average blood loss was 190 ml (range,100-400).There were no complications,such as infection and internal fixation failure.Bony fusion was achieved in all patients.The follow-up was from 14 months to 41 months with 21 months in the average.The average 0swestry scores decreased from preoperative 40.1％±4.1％ to 9.5％±3.7％ three months after the operation.The outcomes of this operation were rated as excellent.ConclusionMicroendoscopic discectomy TLIF or PLIF under X-Tube system in treatment of lumbar degenerative disc diseases has the characteristics of less blood loss,tissue trauma and quick recovery.
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Objective To discuss the strategies for treatment of lower cervical distractive flexion injuries. Methods Sixty-eight patients including 43 males and 25 females at age range of 18-72 years (average 43 years) suffered from lower cervical distractive flexion injuries were operated from January 2002 to June 2007. According to Allen's classification, there were 7 patients at grade Ⅰ, 19 at grade Ⅱ,29 at grade Ⅲ and 13 at grade Ⅳ. Temporary skull traction was used for each subject before surgery. Only posterior approach was performed in 26 patients who were fixated by pedicle screw system,lateral mass screw system or transarticular screw system. Combined anterior and posterior approach was applied for the other 42 patients at one stage. The curative effect was followed up for all patients after the procedures. Results All patients were followed up for 6-65 months ( average 34 months), which showed posterior incision infection in 2 patients who were cured after debridement or change dressing. Two patients with aggravated neural symptome were cured following treatment with methylprednisolone. Neural function was improved at least for one level in all patients except for 18 patients (Frankel A). Of 11 patients at grade B, there were 4 patients improved to grade C and 5 to grade D. Of 10 patients at grade C, there were 6 patients recovered to grade D and 4 to grade E. All 15 patients at grade D reached grade E. It was not found loosening, breakage or defuxion. The graft bone was fused within 3-4 months, with no any complications related to surgical fixation. Conclusions The strategies for lower cervical distractive flexion injuries should be taken according to Allen' s classification. Single posterior procedure is suitable for grade Ⅰ and Ⅱ injuries. While combined posterior and anterior procedure can be used for grade Ⅲ and Ⅳ injuries.