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Objectives:To observe the anatomical location and mechanism of axis ring fractures (ARF) using 3-D CT scans, and propose a new classification for such fractures.Methods:By reviewing prospectively maintained database collecting ARF from 7 medical centers in China, 202 patients were included in this study. According to anatomical location, ARFs were classified into axis arthrosis fracture (AAF) and axis bony damage (ABD). The axis ring was divided into anterior, middle, and posterior rings, based on the border of the pars interarticularis (or pedicle) of axis. According to the features of ARF and previous study, a new classification was proposed based on the anatomical features of different fracture patterns, which was divided into three types and six subtypes (A1, A2, B1, B2, C1 and C2). The incidence of AAF and ABD and their distribution in different location of axis ring and the new classification, were observed.Results:In 202 patients with ARF, 501 anatomical structures were involved. 288 AAFs were found in 178 patients (288/501, 57%), while 213 ABDs were found in 149 patients (213/501, 43%). In anterior ring, 304 structures (304/501, 61%) were involved in injury, with 225 AAF and 79 ABD. In middle ring, 99 structures (99/501, 20%) were involved in injury, and all of them were ABD. In posterior ring, 98 structures (98/501, 19%) were involved in injury, with 63 AAF and 35 ABD. The anterior ring injuries (61%) were more common than middle (20%) or posterior ring (19%). In anterior ring, AAF (84%) were morecommon than ABD (16%); In middle ring, all the injuries were ABD; In posterior ring, AAFs (64%) were more common than ABD (36%). Type A fractures were featured with pedicle fractures and were identified in 30 patients (30/202, 15%). Type A1 fractures were bilateral pedicle fracture lines symmetrically or asymmetrically and identified in 12 (6%) patients; Type A2 fractures were pedicle fracture lineson one side and inferior articular facet injuries or lamina fractures on the otherside and identified in 18 (9%) patients. Type B fractures were featured with superior articular facet injuries or posterior wall of C2 body fractures on one side and identified in 136 patients (67%). Type B1 fractures were superior articular facet injuries or posterior wall of C2 body fractures on one side and pedicle fracture on the other side and identified in 57 (28%) patients; Type B2 fractures were superior articular facet injuries or posterior wall of C2 body fractures on one side and inferior articular facet injuries or lamina fractures on the otherside and identified in 79 (39%) patients. Type C fractures were featured with bilateral superior articular facet injuries or posterior wall of C2 body fractures and identified in 36 patients (18%). Type C1 fractures were bilateral superior articular facet injuries or posterior wall of C2 body fractures symmetrically and identified in 22 (11%) patients; Type C2 fractures were bilateral superior articular facet injuries or posterior wall of C2 body fractures asymmetrically and identified in 14 (7%) patients.Conclusion:ARF could occur in different anatomical locations, and most of these fractures were caused by hyperextension and axial load on superior articular facet on one or two sides. The new CT classification of ARF with three types and six subtypes might provide all fracture patterns, which could be useful for the choice of proper diagnosis and treatment for such fractures.
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Objective The purpose of the retrospective study was to introduce a treatment option for atypical Hangman fractures (AHF) based on a new classification.Methods Sixty-seven patients with Hangman fractures were treated with a comprehensive treatment strategy.Firstly,Hangman fractures were classified as typical or atypical (AHF) lesions using computed tomography scans of the cervical spine.Secondly,AHF was divided into 1 of 4 types (type A1,A2,B1,and B2) devised by us to clarify the feature of injury.Thirdly,the injury status of disco-ligamentous complex (intact/indeterminate/ruptured) was evaluated using magnetic resonance imaging.If it was a stable lesion,conservative treatment was recommended.If not surgical treatment using anterior or/and posterior stabilization and fusion at C2-C3 level was used.Results Fifty-one patients were identified with AHF.According to our classification,thirty patients were classified as type A1,14 cases as typeA2,5 cases as type B1,and 2 cases as type B2 lesions.Thirteen AHF without C2-C3 instability (12 as type A1 and 1 as type B1) were treated with non-operative treatment,and 38 AHF with C2-C3 instability (18 as type A1,14 as type A2,4 as type B1,and 2 as type B2) were treated with operative treatment.Three patients (all with type A1 lesions) with slightly displacement of C2-3 underwent isolated direct screw osteosynthesis.The remaining 35 underwent posterior stabilization and fusion at C2-C3 level:24 patients with posterior approach with C2 lag screws and C3 non-lag screws fixation and fusion (11 as type A1,10 as type A2,2 as type B1,and 1 as type B2);3 patients with posterior approach with C1 and C3 screw-rod fixation and fusion (1 as type A1 and 1 as type B1);7 with anterior approach by C2-3 discectomy and fusion (3 as type A1 and 4 as type A2);and 2 with anterior and posterior approach (1 as type B1 and 1 as type B2).The average follow-up period was 26 months (range,12-86 months).Neck pain improved significantly at 3-month follow-up,and neurologic status improved at least 1 grade in 12 patients with neurologic deficits at final follow-up.Radiological evaluation showed bony fusion in all patients at 12-month follow-up.Radiological evaluation showed that all 13 AHF without C2-C3 instability treated with non-operative treatment gained fractures fusion at 3-6 month follow-up.Posterior approaches with C1 or C2 and C3 screw-rod fixation and fusion were found to obtain a better alignment of C2-C3 and satisfactory fusion of C2 pedicle factures than anterior approach.Conclusion The treatment option for AHF based on a new classification is helpful in managing such fractures,resulting in good clinical and radiological outcomes.C2 lag screws with or without C3 pedicle screws fixation via posterior approach may not only reduce fractures but also obtain alignment of C2-C3 effectively.
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Objective To evaluate the efficacy of pedicle screw fixation combined with bucking bar technique in treatment of C2 pedicle fractures.Methods A retrospective case series study was conducted for 26 cases of C2 pedicle fractures undergone posterior pedicle screw fixation after putting the bucking bar on the anterior surface of C2 via oral cavity from April 2004 to April 2014.There were 19 males and 7 females,with a mean age of 42 years (range,27-71 years).Bilateral C2 pedicle screw placement status,operation time and intraoperative blood loss were recorded.American Spinal Injury Association (ASIA) impairment scale and Visual Analogue Scale (VAS) were used for outcome evaluation.Fracture reduction and symptoms such as sore throat,expectoration,hoarse voice,dysphagia and condition of posterior pharyngeal wall were detected after operation.Results Pedicle fixation of C2 pedicle fractures was completed successfully in 21 cases,repeat C2 pedicle fixation took place in three,and C1-3 fixation was conducted for two.Operation time was (83.2 ± 16.6) min and blood loss was (171.2 ± 115.5)ml.One of the cases experiencing repeat manipulation for screw insertion had transient body balance disorder caused by cerebellar ischemia and recovered within 2 days.X-ray and CT showed complete reduction in 17 cases and incomplete reduction in nine cases.Bony fusion was obtained 6 months after operation.Twenty cases were followed up for 3-46 months (mean,26 months).Final follow-up showed anatomical reduction and bony healing in 19 cases,while malunion in other three cases.ASIA grade improved from C to D in one case,whereas the rest showed a complete neurological recovery (ASIA grade E).VAS improved from preoperative 3-8 points [(5.2 ± 2.5) points] to 0-4 points [(1.6 ±1.5) points] at the final follow-up (P ＜ 0.05).Mild swollen sore throat occurred in four cases after operation.Laryngoscopy showed injury to the posterior pharyngeal wall mucosa (Grade Ⅰ in six cases and Grade Ⅱ in two cases),which were healed within 5-7 days after operation.Conclusion For C2 pedicle fractures,pedicle screw fixation combined with bucking bar technique via oral cavity benefits fracture reduction and stability without apparent impairment to the soft tissue of pharyngeal mucosa.
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Objective To observe the imaging features of partiallythreaded screw fixation using in various kinds of C2 pedicel fracture.Methods CT image materials of 160 Chinese Han patients who suffered from atlantoaxial injury without vertebral body and pedicle fracture of C2 was included in this study,including 120 males and 40 females.Pedical trajectory selected according to Ebraheim method in threedimensional CT reconstruction was analyzed in ADW 4.4 workstation.The posterior wall fracture of C2 vertebral body,isthmus fracture and fractures under C2 laminar were simulated according to clinical observation.The trajectory length (partiallythreaded screw length) from entry point to anterior cortical bone of C2,bolt shank length from entry point to fracture line and fillet of screw length from fracture line to anterior cortical bone of C2 were measured.Relations between height,gender and partiallythreaded screw length bolt shank and fillet of screw length was evaluated.Results Male height was 167±7.9 cm on average,and female was 156±6.6 cm.The length of partiallythreaded screw was 29 mm in male and 25 mm in female on average.Height and gender was positively correlated with partiallythreaded screw length.In posterior wall fracture of C2 vertebral body,length of bolt shank was an average of 17 mm in male and 15mm in female,while fillet of screw length was 12 mm in male and 10 mm in female.The mean length of bolt shank was 14mm in male and 13 mm in female,while mean fillet of screw length was 15 mm in male and 12 mm in female in isthmus fracture.In fractures under C2 laminar,length of bolt shank was 10 mm in male and 9 mm in female on average,while mean fillet of screw length was 18 mm in male and 15mm in female.Conclusion The length of partiallythreaded screw used in posterior axial pedicle fracture may have a close correlation to length and height.The length of bolt shank and fillet of screw was different according to the position of the fracture.
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BACKGROUND: Current commonly used bone graft materials include cancellous bone or bone blocks from ilium, tibia, fibula and others. There is no report of bone graft and fusion in cervical spine from manubrium sterni. OBJECTIVE: To measure lateral X-ray of cervical vertebrae with no degeneration and manubrium sterni samples to explore feasibility of autologous cancellous bone graft of manubrium sterni with pyramesh in anterior cervical spinal fusion surgery, so as to develop a new source of autogenous bone graft.METHODS: A total of 40 manubrium sterni specimens were selected and the length, maximum width and minimum width, thickness, anterior and posterior cortex thickness of manubrium sterni were measured. Manubrium sterni area was calculated: the length, maximum width and minimum width were 4 mm reduced from those of manubrium sterni, its thickness was 2 mm reduced from that of manubrium sterni. The formula of measuring the manubrium sterni volume is (maximum width of manubrium sterni + the minimum width of manubrium sterni)×length of manubrium sterni × thickness of manubrium sterni×1/2. Intervertebral height and vertebral height from C2 to C7 were measured from lateral cervical radiograph of 106 patients with cervical radiolopathy, and the length of pyramesh needed in anterior cervical spinal surgery for one, two, three discs resection, one vertebra plus two discs resection and two vertebrae plus three discs resection was calculated. RESULTS AND CONCLUSION: The manubrium sterni volume was (17 735.51±5 234.92) mm3 and the volume of bone-grafting area was (8 982.83±2 427.76) mm3. The length of pyramesh and volume of bone used in operation were minimal for one disc resection, and maximal for two vertebrae plus three discs resection. The volume of bone graft in the pyramesh was significantly less than the donor area in any anterior cervical spinal fusion operation. Results show that autologous cancellous graft of manubrium sterni combined with pyramesh supporting can be used in anterior cervical spinal fusion surgery. Compared with autologous iliac graft, this method is simpler and does not influence early functional exercise or walking bearing weight.
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Objective To evaluate the clinical result and feasibility of anterior approach with posterior vertebral wall preserved in the treatment of thoracolumbar burst fracture with or without paraplegia. Methods From 2005 to 2010, 68 patients with thoracolumbar burst fracture were treated by corpectomy, strut graft and instrumentation with preserved posterior vertebral wall. There were 49 males and 19 females at average age of 39.8 years (16-62 years). Kyphotic Cobb' s angle and spinal stenotic rate was measured preoperatively and postoperatively. The neurological status was evaluated with Frankel impairment scale. Results All patients were successfully managed with this technique, with no neurological deteriorations, cerebrospinal fluid leakage or incision infections except for the pneumothorax in three patients who were then cured through expectant treatment. Screw distraction was performed for restoration of the disc height and kyphosis in 68 patients. After the fractured fragment became loose and was removed, the dura matter was exposed in 19 patients including the eerebrospinal fluid leakage in three patients. Retrograde lumbar myelography was applied in eight patients, of whom there found the blocked spinal canal in three patients and excision of the posterior vertebral wall was performed. Lack of vertebral distraction was found in two patients and extraction of the reversed bone fracture behind the posterior longitudinal ligament was performed in one. The preservation rate of the posterior vertebral wall was 95% (65/68). Fifty-two patients were followed up for mean 2.2 years (from 3 months to 4.5 years) ,which showed no lower back kyphosis. There showed 1-3 Frankel grades of improvement in spinal cord function except for five patients at Frankel grade A. The Cobb angle was average 18.2° in 68 patients preoperatively and was corrected to 9.7°in 52 patients at last follow-up. CT scan showed that the stenotic rate was 42% preoperatively and 9% at final follow up in 68 patients,with no breakage of the screw and plate. Conclusion In the management of thoracolumbar burst fractures,anterior approach is helpful for preservation of the posterior vertebral wall.
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BACKGROUND: During thoracolumbar anterior operation, implant collapse is an important factor for affecting outcome in patients with thoracolumbar fracture. In particular, osteoporotic patients commonly developed implant collapse, nail channel loose, bone disunion, kyphosis deformation. Bioactive artificial vertebrae of nano-hydroxyapatite and polyamide 66 (n-HA/PA66) has good biocompatibility and biological safety and is an ideal substitute for vertebral body bone graft. OBJECTIVE: To investigate the efficacy of the bioactive artificial verteificial vertebrae of nano-hydroxyapatite and polyamide 66 (n-HA/PA66) for osteoporotic thoracolumbar burst fracture. DESIGN, TIME AND SETTING: A retrospective case analysis was conducted at the Department of Spinal Surgery, Affiliated Hospital of Luzhou Medical College from January 2004 to January 2008. PARTICIPANTS: A total of 20 patients with moderate and severe osteoporotic thoracolumbar fracture (6 males and 14 females) aged 51 -82 years, with an average of 69 years were enrolled in this study. There were 17 cases of fresh fracture and 3 cases of old fracture. n-HAyPA66 was produced by the Sichuan Guona Science and Technology Co., Ltd. This artificial vertebral body was in 10-35 mm diameter, 30-100 mm length, circular cylinder shape, 3-12 mm midheaven diameter, 2.5-6.5 mm tubal wall thickness, with the presence of 2 mm holes surrounding the vertebral body. The contact area of the vertebral body was 78.5-176.7 mm2. Fixity was anterior nail plate system (titanium alloy material) produced by Foshan Shitaibao Company. METHODS: Following conventional tracheal intubation and general anesthesia, at right arm recumbent, according to various fracture-involved segments, different regions were incised and treated with anterior decompression, implanted with artificial vertebrae with the bioactive artificial verteificial vertebrae n-HA/PA66 and fixed with steel plate. MAIN OUTCOME MEASURES: Fracture healing and implant loose were observed by radiograph. Cobb angle, the height of damaged vertebral body and spinal cord function score were compared prior to surgery, 3 months following surgery and the last follow-up. RESULTS: All the patients were successfully operated. Bleeding 200-800 mL during surgery and operation time ranged from 2.0 to 3.0 hours. There were 1 case of pulmonary infection and 1 case of delayed wound healing. A total of 20 patients were followed up for 6-42 months (averagely 18 months). Postoperative radiograph review demonstrated that closed vertebral body was healed three to four months. No significant displacement of implant was found. There was less loss of reestablished vertebral body height. Internal fixation position was good, without nail breakdown or internal fixation loose/displacement. At 3 months following surgery, significant differences in Cobb angle, the height of damaged vertebral body and spinal cord function score were detected compared with that before surgery (P < 0.05). No significant difference in postoperative two follow-up was detected (P > 0.05). CONCLUSION: The bioactive artificial vertebrae of n-HA/PA66 can increase the fusion area, reduce local pressure and prevent loosening of implants and sinking into the vertebrae, finally resulting in restoration of vertebral body height.