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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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Urinary retention is a common complication of bedridden patients in traumatic orthopedics. The severe condition can even cause permanent bladder injury and renal failure, which brings great pain and psychological pressure to patients and seriously hinders their rehabilitation. The traditional Chinese medicine appropriate technologies have the characteristics of safety, effectiveness, low cost, simplicity and easy learning and achieve good clinical effects in the prevention and treatment of bedridden patients with urinary retention in traumatic orthopaedics, including Chinese herbal medicine, acupuncture and moxibustion, massage, etc. The authors summarize the research progress in appropriate technologies of traditional Chinese medicine in the prevention and treatment of bedridden patients with urinary retention in traumatic orthopedics from aspects of action principles, operation methods and effects of acupuncture points, moxibustion therapy, manipulation therapy, external treatment of traditional Chinese medicine and acupoint injection, so as to provide a reference for further nursing research and clinical application.
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Objective:To investigate the safety and efficacy of short-segment fixation covering the fractured vertebrae via posterior intermuscular approach plus percutaneous kyphoplasty (PKP) through the outer upper edge of the base of the fractured vertebral pedicle in the treatment of osteoporotic thoracolumbar burst fracture.Methods:A retrospective case series study was used to analyze the clinical data of 56 patients with osteoporotic thoracolumbar burst fracture admitted to Ningbo No.6 Hospital from January 2018 to February 2021, including 24 males and 32 females; aged 56-72 years [(63.5±4.6)years]. All patients underwent short-segment fixation covering the fractured vertebrae via posterior intermuscular approach combined with PKP through the outer upper edge of the base of the fractured vertebral pedicle. The operation time, intraoperative blood loss, hospitalization day and surgery-related complications were recorded. The visual analogue score (VAS) of back pain, ratios of the anterior, middle and posterior height of the fractured vertebrae and kyphotic Cobb angle were compared before operation, at postoperative 2 days and at the final follow-up.Results:All patients were followed up for 12-28 months [(14.5±2.2)months]. The operation time was 55-85 minutes [(62.0±12.1)minutes], intraoperative blood loss was 80-150 ml [(94.0±18.5)ml], and hospitalization day was 5-9 days [(7.4±1.1)days]. Based on CT examination at postoperative 2 days, there were 2 patients with paravertebral cement leakage, 2 with intervertebral space leakage and 1 with intracanal leakage, but none reported associated clinical symptoms. No implant failure or fractures of adjacent segments was detected during the follow-up period. The VAS was significantly decreased from preoperative (7.5±1.2)points to (3.2±0.8)points at postoperative 2 days ( P<0.01), and the score was further lowered to (2.2±0.8)points at the final follow-up when compared with that at postoperative 2 days ( P<0.01). The ratios of the anterior, middle and posterior height of the fractured vertebrae and kyphotic Cobb angle were significantly improved at postoperative 2 days [(89.5±13.2)%, (85.8±7.9)%, (89.5±9.0)% and (5.6±3.2)°] when compared with those before operation [(48.9±11.8)%, (61.9±11.9)%, (79.9±9.8)% and (26.3±5.6)°] (all P<0.01). Slight losses were observed in the ratios of the anterior, middle and posterior height of the fractured vertebrae and kyphotic Cobb angle at the final follow-up [(87.0±12.7)%, (82.1±7.8)%, (88.6±10.0)% and (5.4±3.2)°], but not significantly different from those at postoperative 2 days (all P>0.05). Conclusion:Short-segment fixation covering the fractured vertebrae via posterior intermuscular approach plus PKP through the outer upper edge of the base of the fractured vertebral pedicle can safely and effectively treat osteoporotic thoracolumbar burst fracture, for it can significantly improve back pain, restore the height of the fractured vertebrae and correct the kyphotic deformity.
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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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Objective:To provide a theoretical basis for the clinical application of the posterior route through atlas occipital articular slope screw internal fixation system through the biomechanical study.Methods:Eight cadavers of healthy adults aged 35-60 years and 155-180 cm in height were selected. The specimens with complete anatomical structure and without surgical operation were established as normal models. The model of occipito-atlantoaxial complex was established by breaking the articular capsule, ligament and other connecting structures and cutting the dentate process. The device was established as an internal fixation model through the specimen of atlantooccipital joint slope screw internal fixation system. Given normal model and internal fixation of 1.5 N·m in the moment of flexion, lateral bending and axial rotation and to measure the specimen C 0-C 1 and C 0-C 2 segment of the range (range of motion, ROM), comparative analysis of pillow neck area within the normal model and fixed model changes the range of movement, after the evaluation through the slope between atlas and the occipital screw internal fixation system of mechanical properties. Results:In the normal model, the flexion, flexion and extension, lateral bend and axial rotation ranges of C 0-C 1 segments were 23.85°±2.43°, 4.74°±0.55°, 5.77°±0.75°, respectively; the corresponding activity ranges of C 0-C 2 segments were 30.66°±3.05°, 9.09°±1.37°, 70.97°±9.48°, respectively; in the internal fixation model, the flexion and extension, lateral bend and axial rotation ranges of C 0-C 1 segments were 0.71°±0.24°, 0.24°±0.06°, 0.34°±0.09°, respectively. The corresponding activity range of C 0-C 2 segment was 3.09°±0.82°, 0.74°±0.07°, 1.22°±0.10°, respectively. Compared with the normal model, the range of activity of the internal fixation model in all directions was significantly reduced (<3°), and the reduction ratio of activity was more than 90%. Conclusion:The posterior route through pillow slope screw internal fixation system can effectively reduce the range of motion of the occipital neck in flexion, extension, lateral bending and rotation, and has safe and reliable biomechanical stability.
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Objective:To compare the effects of 3 spatial locations of the screw at the injured vertebra on the vertebral height in AO type A thoracolumbar fracture.Methods:A retrospective analysis was performed of the 156 patients with type A thoracolumbar fracture who had been hospitalized at Department of Spine Surgery, The Sixth Hospital of Ningbo from January 2016 to June 2019. They were divided into 3 groups according to the spatial location of the screw at the injured vertebra. In group A of 55 cases, the screws were located in the vertebral body between the longitudinal axis bisector of the vertebral pedicle and the upper endplate; in group B of 52 cases, the screws were located in the vertebral body between the vertical axis bisector of the vertebral pedicle and the horizontal line of the apex of the inferior pedicle notch; in group C of 49 cases, the screws were located in the vertebral body between the horizontal line at the apex of the inferior pedicle notch and the inferior endplate. The anterior, middle and posterior heights of the injured vertebra, Beck index and angulation of the injured vertebra at preoperation, one week postoperation and the last follow-up were compared between the 3 groups and within the same group.Results:There was no significant difference in preoperative general data between the 3 groups, showing comparability ( P>0.05). In all the 3 groups, the anterior and middle heights of the injured vertebra and Beck indexes at one week postoperation and at the last follow-up were significantly larger than those before operation while the angulations of the injured vertebra at one week postoperation and at the last follow-up were significantly smaller than the preoperative values (all P<0.05), but there was no significant difference between one week postoperation and the last follow-up in any of the above indexes ( P>0.05). In all the patients, the posterior height of the injured vertebra at one week postoperation was significantly larger than those before operation and at the last follow-up ( P<0.05), but there was no such a significant difference in comparison between preoperation and the last follow-up ( P>0.05). At the last follow-up, groups A and B had significantly larger anterior and middle heights of the injured vertebra and Beck indexes but significantly smaller angulations of the injured vertebra than group C, but such significant differences did not exist when the above indexes were compared between groups A and B ( P>0.05). Conclusions:In insertion into an injured vertebra, the screw should be parallel and close to the upper endplate, and located in the middle and upper part of the vertebra corresponding to the longitudinal axis of the vertebral pedicle, because this spatial position is conducive to intraoperative reduction, maintaining the postoperative height of the injured vertebra, and decreasing loss of the vertebral height.
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Objective:To explore the difference in properties of anterior occipital condyle plate screws compared with common anterior occipitalcervical fusion internal fixation.Methods:A 28-year-old healthy adult male volunteer's CT data of the occiput and neck was selected to establish finite element models：including the normal model，simple artificial vertebral fixation model（special-shaped titanium cage+clival screws），anterior occipital condyle plate and screw fixation model，and clival plate and screw fixation model，then a 50 N gravity and a torque of 1.5 N m were exerted upon the upper surface of the occipital bone to make the model produce flexion and extension，lateral bending and rotation. The motion range，internal fixation stress distribution and occipital bone stress distribution of each model under varying conditions were compared.Results:Under the conditions of flexion，extension，lateral bending and rotation，the range of motion of the normal model was 18.65°，15.35°，9.82° and 34.68°，respectively；that of the simple artificial vertebral fixation model was 3.20°，3.63°，2.94° and 3.92°，respectively；that of the clival plate and screw fixation model was 0.40°，0.50°，0.35° and 0.89°，respectively；that of the anterior occipital condylar plate and screw fixation model was 0.27°，0.33°，0.13° and 0.30°，respectively. Compared with the simple artificial vertebral fixation model，the range of motion of the clival plate and screw fixation model decreased by 87.5%，86.2%，88.1% and 77.3% in flexion，extension，lateral bending and rotation. The range of motion of the anterior occipital condylar plate and screw fixation model decreased by 91.5%，90.1%，95.6% and 92.3%，respectively. Under the conditions of flexion and extension，lateral bending and rotation，the stress peak of the simple artificial vertebral fixation model was 52.3 MPa，51.9 MPa，52.6 MPa，respectively；that of the clival plate and screw fixation was 100.1 MPa，158.1 MPa，170.6 MPa，respectively；that of the anterior occipital condylar plate and screw fixation was 114.2 MPa，62.9 MPa，132.9 MPa，respectively. Under the condition of flexion and extension，lateral bending and rotation，the stress peak of the occipital bone in the simple artificial vertebral body internal fixation model was 52.9 MPa，50.9 MPa and 62.3 MPa，respectively；that of the clival plate and screw fixation model was 19.7 MPa，55.9 MPa and 38.3 MPa，respectively；that of the anterior occipital condylar plate and screw fixation model was 37.8 MPa，15.0 MPa and 16.3 MPa，respectively. The stress in bone near the hypoglossal canal was close to 0 MPa，much smaller than the stress peak in occipital bone.Conclusion:Anterior occipital condylar plate and screw fixation in front of the special-shaped titanium cage can improve the stability of occipitocervical fusion with little effect on the occipital bone and hypoglossal canal or without obvious stress concentration，and hence is a safe and reliable anterior fixation method for upper cervical spine instability.
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Objective:To analyze the incidence and epidemiological characteristics of traumatic spinal cord injury in China in 2018.Methods:Multi-stage stratified cluster sampling was used to randomly select hospitals capable of treating patients with spinal cord injury from 3 regions，9 provinces and 27 cities in China to retrospectively investigate eligible patients with traumatic spinal cord injury admitted in 2018. National and regional incidence rates were calculated. The data of cause of injury，injury level，severity of injury，segment and type of fracture，complications，death and other data were collected by medical record questionnaire，and analyzed according to geographical region，age and gender.Results:Medical records of 4，134 patients were included in this study，with a male-to-female ratio of 2.99∶1. The incidence of traumatic spinal cord injury in China in 2018 was 50.484 / 1 million （95% CI 50.122-50.846）. The highest incidence in the Eastern region was 53.791 / 1 million （95% CI 53.217-54.365）. In the whole country，the main causes of injury were high falls （29.58%），as well as in the Western region （40.68%），while the main causes of injury in the Eastern and Central regions were traffic injuries （31.22%，30.10%）. The main injury level was cervical spinal cord in the whole country （64.49%），and the proportion of cervical spinal cord injury in the Central region was the highest （74.68%），and the proportion of lumbosacral spinal cord injury in the Western region was the highest （32.30%）. The highest proportion of degree of injury was incomplete quadriplegia （55.20%），and the distribution pattern was the same in each region. A total of 65.87% of the patients were complicated with fracture or dislocation，77.95% in the Western region and only 54.77% in the Central region. In the whole country，the head was the main combined injury （37.87%），as well as in the Eastern and Central regions，while the proportion of chest combined injury in the Western region was the highest （38.57%）. A total of 32.90% of the patients were complicated with respiratory complications. There were 23 patients （0.56%） died in hospital，of which 17（73.91%） died of respiratory dysfunction. Conclusions:The Eastern region of China has a high incidence of traumatic spinal cord injury. Other epidemiological features include high fall as the main cause of injury cervical spinal cord injury as the main injury level，incomplete quadriplegia as the main degree of injury，head as the main combined injury，and respiratory complications as the main complication.
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Objective:To investigate the characteristics and causes of endplate injury in the oblique lateral interbody fusion for the treatment of lumbar diseases, and summarize the precaution of endplate injury.Methods:Thirty-five cases of endplate injury were observed, which were originally treated with oblique lateral interbody fusion with or without pedicle screw fixation from October 2014 to December 2017. There were 7 males and 28 females, and the age ranged from 51 to 78 years old (averagely 62.8±8.13 years). There were 2 cases of lumbar disc degeneration, 10 cases of lumbar canal stenosis, 17 cases of lumbar degenerative spondylolisthesis, 2 cases of lumbar spondylolysis with or without spondylolisthesis, and 4 cases of lumbar degenerative scoliosis. Lesion sites contained L 3,4 in 2 cases, L 4,5 in 21 cases, L 2-4 in 3 cases, L 3-5 in 4 cases, L 2-5 in 3 cases and L 1-5 in 2 cases. Preoperative bone mineral density examination revealed there were 7 cases of T>-1 SD, 24 cases of -2.5 SD<T<-1 SD and 4 cases of T<-2.5 SD. There were 5 cases of high iliac crest. There were 25 cases of single segment, 5 cases of double segment, 3 cases of three segments, and 2 cases of four segments. Endplate injury occurred in all cases, and a total of 40 endplates occurred in 39 intervertebral spaces, of which the upper and lower endplates of 1 intervertebral space were injured, and the rest were single endplate injuries. There were 35 cases of upper endplate injury, 5 cases of lower endplate injury and 3 cases combined with vertebral fracture. The cage location where the endplate injury occurred: 3 cases in zone Ⅰ-Ⅱ, 31 cases in zone Ⅱ-Ⅲ and 5 cases in zone Ⅲ-Ⅳ. The main observation indicators were Visual Analog Scale (VAS) for low back pain, Oswestry disability index (ODI), intervertebral space height, and position of cage. Results:The reasons for endplate injury were: osteopenia or osteoporosis 28 cases, improper surgical steps 9 cases, high iliac crest 5 cases, endplate anatomical morphology variation 5 cases, obvious stenosis of the intervertebral space 4 cases, large cage 3 cases and mixed factors 12 cases. The follow-up time was 18.5±8.1 months. There was no pedicle screw loosen during the follow-up. There were 3 cases of lateral displacement of cage, including 1 case of Stand-alone OLIF, 2 cases of OLIF combined with pedicle screw fixation. In all cases, different degrees of cage subsidence occurred. Among them, 7 cases of Stand-alone OLIF were supplemented with posterior pedicle screw fixation. The intervertebral height of diseased segment was well restored postoperatively, which was statistically significant compared with preoperative. But there was significant loss during the follow-up, and the difference was statistically significant at the last follow-up. The low back pain VAS score was from 6.6±2.2 preoperative to 1.3±0.74 at the last follow-up, which was statistically different. The ODI was from 36.3%±7.4% preoperative to 9.6%±3.5% at the last follow-up, which was statistically different. Except 3 cases, the remaining had well interbody fusion, with the fusion rate of 91.4%.Conclusion:The incidence of endplate injury during oblique lateral interbody fusion is high. The reasons of endplate injury include both the patient's factors and the surgical factors. Endplate injury is closely related to the decreased intervertebral space height during the follow-up period, as well as the settlement or displacement of cage. Some cases may require reoperation. The prevention of endplate injury should be strengthened. Once it occurs, timely and effective treatment should be taken, and follow-up should be done closely.
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Objective:To investigate the safety and feasibility of the occipital condyle screw and evaluate the safepath parameters for the occipital condyle screw.Methods:Data of 64 patients with upper cervical computed tomographic angiograms from September 2016 to September 2018 were retrospectively collected. Excluded occipito-cervical injury, tumor, and vertebral artery course variation. Mimics software was used to reconstruct the occiput, atlas and vertebral artery. Three candidate entry points were placed for each occipital condyle, the midpoint of posterior of occipital condyle as middle entry point, and the medial and lateral entry points were located 3 mm medial and lateral to the middle entry point. The vertebral artery-occipital bone distance (VOD) of each entry point were measured on sagittal plane, and the minimum feasible value was determined to be 4mm. After that 3.5 mm diameter virtual screw was inserted into each candidate entry point with VOD>4 mm, each screw with maximum and minimum cranial angulation was combined with appropriate medial angulation to get the maximum screw length. Then, the screw placement parameters were measured by 3-Matic, and the safe range of cranial angulation and the success rate of screw placement were calculated.Results:The VOD of medial and middle entry point were 8.07±2.13 mm and 7.70±2.19 mm respectively, and the feasibility rate of screw placement of those entry point were 97.7% and 96.1%, respectively. There were significant differences inVOD and feasibility rate of screw placement between medial and middle entry point. The VOD of lateral entry point was 5.63±1.66 mm, and the feasibility rate was only 78.9%, which was significantly lower than that of medial and middle entry point. The lateral entry point could obtain a larger medial angulation, which was supplemented by a longer screw length. The medial angulation and length of screw gradually decreased with the inward movement of the entry point. There were significant differences in medial angulation and screw length among groups. The safe range of cranial angulation of medial, middle and lateral entry points were 8.17°±2.55°, 12.58°±4.23° and 12.09°±3.83°, respectively, and the difference were statistically significant. Among the screw entry point that could accommodate screw fixation, the maximum screw placement success rate can be obtained by adding 5° cranial angulation to the lateral and middle entry point, which were 98.02% and 98.37%, respectively,while 100% success rate of screw placement could be obtained at the medial entry point at 3° cranial angulation.Conclusion:In the selection of the entry point in the horizontal direction, middle and medial entry points have higher success rate of screw placement and wider safe range of cranial angulation because of less affection of horizontal segment of the vertebral artery. However, the screw length of medial entry point is much shorter than middle and lateral entry point. As a result, the middle entry point may be an optimal entry point for the occipital condyle screw.
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Objective:To determine the biomechanical stability of atlantoaxial and occipitocervical fixations with unilateral spinous process screw plus contralateral pedicle screw.Methods:After nonlinear finite element models of the intact upper cervical spine (C0-3) were constructed and validated, they were processed into 3 kinds with normal axis anatomy, a high-riding vertebral artery and a thin axis lamina, re-spectively.In the models, the odontoid fracture stabilized by atlantoaxial fixation and the atlas fracture sta-bilized by occipitocervical fixation were simulated.In the atlantoaxial fixation, the group of unilateral spinous process screw+contralateral pedicle screw+bilateral atlas lateral mass screws (spinous process screw group) was compared with that of bilateral axis pedicle screws+bilateral atlas lateral mass screws (pedicle screw group); in the occipitocervical fixation, the group of unilateral spinous process screw+contralateral pedicle screw+occipital screws (spinous process screw group) was compared with that of bilateral axis pedicle screws+occipital screws (pedicle screw group).Three different techniques in insertion of spinous process screws (horizontal, oblique and vertical) were applied.The range of motion (ROM) was measured in extension-flexion, lateral flexion and rotation of occipitocervical bodies (C0-C3) after internal fixation.Results:Compared with the intact models, the ROMs of extension-flexion, lateral flexion and rotation of C1-C2 were obviously reduced in the spinous process screw group and the pedicle screw group in the models with atlantoaxial and occipitocervical fixations.In the atlantoaxial fixation, the ROMs of extension-flexion, lateral flexion and rotation of C1-C2 were greater in the spinous process screw group than in the pedicle screw group; in the occipitocervical fixation, the spinous process screw group had greater ROM of lateral flexion of C1-C2 and greater ROM of rotation of C0-C2 than the pedicle screw group.There were unobvious differences in insertion of spinous process screws between the horizontal, oblique and vertical techniques.Conclusions:In the atlantoaxial and occipitocervical fixations, the unilateral spinous process screw plus contralateral pedicle screw can provide as fine stability as the bilateral axis pedicle screws.In the atlantoaxial fixation, the bilateral axis pedicle screws may lead to better stability of C1-C2 than the unilateral spinous process screw plus contralateral pedicle screw.In the occipitocervical fixation, the bilateral axis pedicle screws may lead to better stability of C1-C2 in lateral flexion and rotation than the unilateral spinous process screw plus contralateral pedicle screw. The 3 different techniques in insertion of spinous process screws lead to an unobvious difference in the stability of C1-C2.
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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,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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Appropriate surgical method selection is the basis of treatment of unstable upper cervical spine fracture.Improving the accuracy of screw placement is the key to reduce complications and enhance the efficacy.With the release of several clinical diagnosis and treatment guidelines for upper cervical fractures and the usage of various auxiliary screw placement techniques in the treatment of upper cervical fractures,the safety and efficacy of surgical treatment of unstable upper cervical fractures have made some progress,but there are still deficiencies including neurovascular injury,nonunion and failure of internal fixation caused by poor internal fixation.The author discusses how to choose the surgical method and the application of 3 D printing,microscope assistance,computer navigation and robot-assisted technology in the operation of upper cervical fracture,so as to provide reference for the treatment of upper cervical fracture and provide theoretical basis for the innovation and improvement of operation technology.
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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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Appropriate surgical method selection is the basis of treatment of unstable upper cervical spine fracture. Improving the accuracy of screw placement is the key to reduce complications and enhance the efficacy. With the release of several clinical diagnosis and treatment guidelines for upper cervical fractures and the usage of various auxiliary screw placement techniques in the treatment of upper cervical fractures, the safety and efficacy of surgical treatment of unstable upper cervical fractures have made some progress, but there are still deficiencies including neurovascular injury, nonunion and failure of internal fixation caused by poor internal fixation. The author discusses how to choose the surgical method and the application of 3D printing, microscope assistance, computer navigation and robot-assisted technology in the operation of upper cervical fracture, so as to provide reference for the treatment of upper cervical fracture and provide theoretical basis for the innovation and improvement of operation technology.