Objective To explore and evaluate the accuracy and feasibil ity of individual rapid prototype (RP) drill templates for atlantoaxial pedicle screw implantation. Methods Volumetric CT scanning was performed in 8 adult cadaveric atlas and axis to collect Dicom format datas. Then three-dimensional (3D) images of atlas and axis were reconstructed and the parameters of pedicles of 3D model were measured by using software Mimics 10.01. The 3D model was saved by STLformat in Mimics. The scattered point cloud data of 3D model were processed and the 3D coordinate system was located in software Imageware 12.1. The curves and surfaces of 3D model were processed in software Geomagic Studio 10. The optimal trajectory of pedicle screw was designed and a template was constructed which accorded with the anatomical morphology of posterior arch of atlas and lamina of axis by using software Pro/Engineer 4.0. The optimal trajectory of pedicle screw and the template were integrated into a drill template finally. The drill template and physical models of atlas and axis were manufactured by RP (3D print technology). The accuracy of pilot holes of drill templates was assessed by visually inspecting and CT scanning. Results The individual drill template was used conveniently and each template could closely fit the anatomical morphology of posterior arch of atlas and lamina of axis. Template loosening and shifting were not found in the process of screw implantation. Thirty-two pedicle screws were inserted. Imaging and visual inspection revealed that the majority of trajectories did not penetrate the pedicle cortex, only 1 cortical penetration was judged as noncritical and did not injury the adjacent spinal cord, nerve roots, and vertebral arteries. The accuracy of atlas pedicle screw was grade 0 in 15 screws and grade I in 1 screw, and the accuracy of axis pedicle screw was grade 0 in 16 screws. Conclusion The potential of individual drill templates to aid implantation of atlantoaxial pedicle screw is promising because of its high accuracy.
【Abstract】 Objective To determine the three-dimensional stabil ity of atlantoaxial reconstruction withanterior approach screw fixation through C2 vertebral body to C1 lateral mass and Gall ie’s technique (ASMG) for C1,2instabil ity. Methods Twenty-five human cadaveric specimens (C0-3 ) were divided randomly into 5 groups (n=5). Thethree-dimensional ranges of motion C1 relative to C2 were measured under the five different conditions：the intact state group (group A), type II odontoid fracture group (group B), posterior C1,2 transarticular screw fixation group (group C), ASM group (group D) and ASMG group (group E). The three-dimensional ranges of motions C1 relative to C2 by loading ± 1.5 Nm were measured under the six conditions of flexion/extension, left/right lateral bending, and left/right axial rotation. The obtained data was statistically analyzed. Results In each group, the three-dimensional ranges of motion C1 relative to C2 under the six conditions of flexion/extension, left/right lateral bending, and left/right axial rotation were as follows: in group A (8.10 ± 1.08), (8.49 ± 0.82), (4.79 ± 0.47), (4.93 ± 0.34), (28.20 ± 0.64), (29.30 ± 0.84)°; in group B (13.60 ± 1.25), (13.80 ± 0.77), (9.64 ± 0.53), (9.23 ± 0.41), (34.90 ± 0.93), (34.90 ± 1.30)°; in group C (1.62 ± 0.10), (1.90 ± 0.34), (1.25 ± 0.13), (1.37 ± 0.28), (0.97 ± 0.14), (1.01 ± 0.17)°; in group D (2.03 ± 0.26), (2.34 ± 0.49), (1.54 ± 0.22), (1.53 ± 0.30), (0.80 ± 0.35), (0.76 ± 0.30)°; in group E (0.35 ± 0.12), (0.56 ± 0.34), (0.44 ± 0.15), (0.55 ± 0.16), (0.43 ± 0.07), (0.29 ± 0.06)°. Under the six conditions, there were generally significant differences between group A and other four groups, and between group B and groups C, D and E (P lt; 0.001), and between group E and groups C, D in flexion/ extension and left/right lateral bending (P lt; 0.05). There was no significant difference between group E and groups C, D in left/right axial rotation (P gt; 0.05). Conclusion In vivo biomechanical studies show that ASMG operation has unique superiority in the reconstruction of the atlantoaxial stabil ity, especially in controll ing stabil ity of flexion/extension and left/right lateral bending, and thus it ensures successful fusion of the implanted bone. It is arel iable surgical choice for the treatment of the obsolete instabil ity or dislocation of C1, 2 joint.
Objective To study the prevention and management of early compl ications associated with anterior cervical spinal surgery. Methods From November 1998 to December 2006, 363 cases were treated with anterior cervicalsurgery, including 268 males and 95 females aged 17-79 years．In these cases, 224 suffered from cervical spondylosis, 39 from cervical disc herniation, 87 from cervical trauma, 9 from cervical tumor and 4 from cervical tuberculosis. Forty-eight cases with anterior cervical surgery were fused by autogenous il iac bones, 132 cases with anterior cervical surgery were fused by autogenous il iac bones and anterior cervical spine locking plates, and 183 cases with anterior cervical surgery were fused by titanium mesh cage and anterior cervical spine locking plates. Results A total of 282 cases were followed up for 3 months to 5 years with the average of 1 year and 11 months. Twenty-three compl ications associated with surgery were found, with an incidence of 8.16%. Three cases of transient superior laryngeal nerve palsy recovered within 3-7 days after the restriction of l iquid diet and fluid replacement. Two cases of recurrent laryngeal nerve palsy recovered by 3-month pronunciation practice. One case of spinal cord injury was treated with medicine for dehydration and anti-inflammation, and was restored to preoperative muscle power of inferior extremity after 6 months. Two cases of CSF leakage were cured with moderate local compression and meticulous water-tight wound closure. Among the 10 patients with compl ications of internal fixation, one suffering mild dysphagia was reoperated, while the others were treated with cephal-cervico-thorax plaster external fixation and recovered with sol id fusion within 3-18 months. Among the 4 cases with cervical hematoma, 1 died of wrong rescue procedures and 1 was infected. Conclusion Adequate preoperative preparation, thorough understanding of anatomy related to the anterior approach and skilled surgical technique are essential for preventing the early postoperative compl ications of anterior cervical spinal surgery．
Objective To explore the anatomic basis for theanterior approach screw fixation through the C2 vertebral body into the C1 lateral mass and toinvestigate its primary clinical application. Methods Twenty-one adult corpse specimens were anatomically measured. The minimum lateral angle α, the maximum lateral angle β, and the maximum posterior angle γ were calculated based on the data from the anatomic measurement. All the specimens were given an X-ray examination, the minimum lateral angle α, the maximum lateral angle β, and the maximum posterior angle γ were measured. The statistical analysis was made on the data obtained from the calculation in the specimens and the measurement in the X-ray films. The simulation of the approach was made onthe specimen. From October 2004 to July 2006, the simulated approach was used in 5 patients (3 males, 2 females; age, 30-55 years; illness course, 3 months-2 years) with the old atlanto-axial joint dislocation . The Frankel grading system revealed the spinal cord injury degree as follows: 1 patientwas in Grade B, 2 in Grade C, and 2 in Grade D. All the patients were treated with this surgical approach. The postoperative X-ray and CT examinations were performed. Results Angle α was 14.0±1.6°, β was 30.0±2.3°, γ was 29.0±2.9°. No significant difference existed between the angles calculated in the specimens and measured in the X-ray films (Pgt;0.05). The angles for the practical application during operation were as follows: α was 11.2±1.6°, β was 28.8±2.3°, and γ was 29.3±2.9°. The follow-up for an average of 14 months revealed that 1 patient recovered to Grade C, 1 to Grade D2, and 3 to Grade D3 in the spinal cord function according the modified Frankel grading system.Conclusion The anterior approach screw fixation through the C2 vertebral body into the C1 lateral massis feasible and safe in treatment of the old atlantoaxial joint dislocation ifthe screw insertion is exact in direction. This technique only makes the atlas temporarily stable, and so the posterior bone graft should be added into the atlantoaxial joint immediately in the one- or two-stage operation so as to achieve a long-lasting stability.
Objective To review the progress of surgical treatment for the thoracolumbar spinal tuberculosis. Methods The related literature of surgical treatment for the thoracolumbar spinal tuberculosis was reviewed and analyzed from the aspects such as surgical approach, fixed segments, fusion ranges, bone graft, and bone graft material research progress. Results Most scholars prefer anterior or combined posterior approach for surgical treatment of thoracic and lumbar tuberculosis because it possessed advantage of precise effectiveness. In recent years, a simple posterior surgery achieved satisfactory effectiveness. The fixation segments are mainly composed of short segments or intervertebral fixation. The interbody fusion is better for the bone graft fusion range and manner, and the bone graft materials is most satisfied with autologous iliac Cage or titanium Cage filled with autologous cancellous bone. Conclusion The perfect strategy for treating the thoracolumbar spinal tuberculosis has not yet been developed, and the personalized therapy for different patients warrants further study.
Objective To study the clinical effects of the artificial vertebral body of the biomimetic nanohydroxyapatite/polyamide 66 (nHA/PA66) compositefor the structural reconstruction and the height restoring of the vertebral body in the thoracolumbar fractures by the anterior surgical procedures. Methods From December 2003 to January 2006, 42 patients with thoracolumbar fractures received the anterior surgical procedures to decompress and reconstruct the spinal vertebral structure with the artificial vertebral body of the nHA/PA66 composite. Among the patients, there were 28 males and 14 females, aged 1767 years, averaged 43.6 years. The thoracolumbar fractures developed at T12 in 5 patients, at L1 in 17, at L2 in 14, and at L3 in 6. The height of the anterior border of thevertebral body amounted to 29%-47% of the vertebral body height, averaged 40.6%.The Cobb angle on the sagittal plane was 2138° averaged 27.6°. According tothe Frankel grading scale, the injuries to the nerves were as the following: Grade A in 7 patients, Grade B in 19, Grade C in 8, Grade D in 6, and Grade E in 2. Results All the 42 patients were followed up for 625 months. Among the patients, 36 were reconstructed almost based on the normal anatomic structure, and 6 were well reconstructed. The mean height of the anterior border of the vertebralbody was 40.6% of the vertebral body height before operation but 91.7% after operation. And the reconstructed height of the vertebra was maintained. The mean Cobb angle on the sagittal plane was 27.6°before operation but 13.4° after operation. All the patients had a recovery of the neurological function that had a 1grade or 2grade improvement except 7 patients who were still in Grade A and 2 patients who were in Grade D. The implant was fused 35 months after operation. No infection, nail break, bar/plate break or loosening of the internal fixation occurred. Conclusion The artificial vertebral body of the biomimetic nHA/PA66 composite can effectively restore the height and the structure of the vertebra, can be fused with the vertebral body to reconstruct the spinal structural stability effectively, and can be extensively used in the clinical practice.
ObjectiveTo compare the biomechanical differences between the kidney-shaped nano-hydroxyapatite/polyamide 66 (n-HA/PA66) Cage and the bullet-shaped n-HA/PA66 Cage. MethodsL2-L5 spinal specimens were selected from 10 adult male pigs. L2, L3 and L4, L5 served as a motor unit respectively, 20 motor units altogether. They were divided into 4 groups (n=5):no treatment was given as control group (group A); nucleus pulposus resection was performed (group B); bullet-shaped Cage (group C), and kidney-shaped Cage (group D) were used in transforaminal lumbar interbody fusion (TLIF) through left intervertebral foramen and supplemented by posterior pedicle screw fixation. The intervertebral height (IH) and the position of Cages were observed on the X-ray films. The range of motion (ROM) was measured. ResultsThere was no significant difference in the preoperative IH among 4 groups (F=0.166, P=0.917). No significant change was found in IH between at pre- and post-operation in group B (P>0.05); it increased after operation in groups C and D, but difference was not statistically significant (P>0.05). There was no significant difference in the postoperative IH among groups B, C, and D (P>0.05). The distance from Cage to the left margin was (3.06±0.51) mm in group C (close to the left) and (5.68±0.69) mm in group D (close to the middle), showing significant difference (t=6.787, P=0.000). The ROM in all directions were significantly lower in groups C and D than in groups A and B (P<0.05), and in group A than in group B (P<0.05). The right bending and compression ROM of group C were significantly higher than those of group D (P<0.05), but no statistically significant difference was found in the other direction ROM (P>0.05). ConclusionThe bullet-shaped and kidney-shaped Cages have similar results in restoring IH and maintaining the stability of the spine assisted by internal fixation. Kidney-shaped Cage is more stable than bullet-shaped Cage in the axial compression and the bending load opposite implant, it can be placed in the middle and back of the vertebral body more ideally.
ObjectiveTo systematically review the effectiveness and safety of dynamic neutralization system (Dynesys) versus posterior lumbar interbody fusion (PLIF) for lumbar degenerative disease. MethodsDatabases including PubMed, EMbase, The Cochrane Library (Issue 5, 2016), CNKI, CBM, VIP and WanFang Data were searched to collect studies about Dynesys versus PLIF for lumbar degenerative disease from inception to May 31st 2016. Two reviewers independently screened literature, extracted data, and evaluated the methodological quality of included studies. Then, meta-analysis was performed using RevMan 5.3 software. ResultsA total of 22 studies involving 1 482 patients were included. The results of meta-analysis showed that, compared with PLIF, Dynesys could reduce operative time (MD=-29.62, 95%CI -36.67 to -22.57), operative blood loss (MD=-112.10, 95%CI -130.60 to -93.61), length of hospital stay (MD=-2.62, 95%CI -4.96 to -0.28), postoperative adjacent segment ROM (MD=-1.29, 95%CI -1.72 to -0.86) and maintain postoperative operated segment ROM (MD=3.53, 95%CI 1.99 to 5.08). There were no significant differences between two groups in postoperative ODI (MD=-1.51, 95%CI -3.58 to 0.55), postoperative back VAS (MD=-0.15, 95%CI -0.38 to 0.08), postoperative leg VAS (MD=-0.09, 95%CI -0.22 to 0.04) and postoperative complications (OR=0.69, 95%CI 0.45 to 1.06). ConclusionThe current evidence shows that compared with PLIF, Dynesys for lumbar degenerative disease has shorter operative time, less operative blood loss, shorter hospitalization days, and Dynesys can also maintain operated segment ROM and delay the degeneration of adjacent segment. Due to the limited quality of the included studies, more studies are needed to verify the above conclusion.
ObjectiveTo compare the short-term effectiveness of one-stage posterior debridement with non-structural bone graft and structural bone graft in the treatment of single segment thoracic tuberculosis.MethodsThe data of 61 patients with single segment thoracic tuberculosis, who were treated by one-stage posterior debridement, bone graft fusion, and internal fixation between June 2011 and August 2015, was retrospectively analyzed. All of them, 26 cases were treated with structural bone graft (group A) and 35 cases with non-structural bone graft (group B). No significant difference was found between the two groups in gender, age, disease duration, comorbidity, involved segments, paravertebral abscess, and preoperative American Spinal Injury Association (ASIA) grade, C reactive protein (CRP), visual analogue scale (VAS) score, and Cobb angle of involved segments (P>0.05). But the preoperative erythrocyte sedimentation rate (ESR) in group B was significantly lower than that in group A (t=3.128, P=0.003). The operation time, intraoperative blood loss, hospitalization stay, VAS score, ESR, CRP, ASIA grade, postoperative complications, Cobb angle of involved segments and its correction rate and loss rate, and bone fusion time were recorded and compared between the two groups.ResultsCompared with group A, group B had shorter operation time, less intraoperative blood loss, and longer hospitalization stay, showing significant differences (P<0.05). The follow-up time of group A was (36.3±10.0) months, which was significantly longer than that of group B [(18.4±4.2) months] (t=10.722, P=0.000). At last follow-up, the VAS score, ESR, and CRP in the two groups all significantly improved when compared with those before operation (P<0.05); the CRP of group B was significantly higher than that of group A (t=–2.947, P=0.005); but there was no significant difference in ESR and VAS score between the two groups (P>0.05). At last follow-up, the ASIA grade of the two groups significantly improved when compared with those before operation, and there was no significant difference between the two groups (Z=–1.104, P=0.270). There were 9 cases and 10 cases of complications in groups A and B, respectively, and there was no significant difference (χ2=0.254, P=0.614). The Cobb angle in group B was significantly higher than that in group A at 3 days after operation (t=–2.861, P=0.006), but there was no significant difference in Cobb angle between the two groups at last follow-up (t=–1.212, P=0.230). The postoperative correction rate and loss rate of Cobb angle in group A were higher than those in group B, and there was a significant difference in the loss rate between the two groups (t=2.261, P=0.031). All patients got bone graft fusion and the bone fusion time of group B was significantly shorter than that of group A (t=4.824, P=0.000).ConclusionNon-structural and structural bone graft can both achieve good effectiveness in the treatment of single segment thoracic tuberculosis, but the former has the advantages of less surgical trauma and shorter fusion time.
Objective To explore the surgical feasibil ity and cl inical outcome of transpedicle screw fixation in treatment of atlantoaxial instabil ity and dislocation. Methods From January 2007 to June 2009, 16 patients with atlantoaxial instabil ity and dislocation were treated with transpedicle screw fixation. There were 13 males and 3 females, with a mean age of 42 years (range, 24-61 years). The transpedicle screw fixation was employed in 5 patients with old odontoid fracture (4 of Anderson type II and 1 of type III), in 4 patients with fresh odontoid fracture, in 4 patients with traumatic disruption of transverse atlantal l igament, and in 3 patients with congenital odontoid disconnection for atlantoaxial instabil ity. All patients had symptoms of cervical pain and l imition of cervical motion, 10 patients compl icated by dyscinesia and hypoesthesia of extremities. The Japanese Orthopaedic Association (JOA) score before operation was from 5 to 13, with an average of 8.5. The image examination showed atlantoaxial instabil ity or dislocation in all patients. Granulated autogenous il ium (20-30 g) was placed onto the surface of the posterior arches of both atlas and axis in some patients with old fracture of odontoid process or disruption of transverse atlantal l igament. Results The mean operative time and bleeding amount were 1.6 hours (1.2-2.5 hours) and 100 mL (50-200 mL), respectively. All the incision healed by first intension. All patients were followed up for 3-18 months, with an average of 11.5 months. The JOA score 3 months after operation was from 12 to 17, with an average of 14.2. All screws were successfully placed in atlas and axis. No postoperative compl ications such as vertebral artery injury, dural rupture, exacerbation of neurological symptoms, wound infection, and broken srews were observed in 16 cases. Postoperative radiograph and CT showed that only one screw penetrated into vertebral canal, but there was no neurological symptoms. Bony fusion was observed after 6 to 18 months of operation, and atlantoaxial rotational function in all patients restored satisfactorily, but axial rotation was partially lost. Conclusion Transpedicle screw fixation in upper cervical spine for treatment of atlantoaxial instabil ity and dislocation is safe and rel iable