Objective To study the correlation between the cervical posture in the cervical disc replacement (CDR) and the cervical curve restoration in neutral position after surgery. Methods Between January 2008 and August 2010, 51 patients underwent single segmental PRESTIGE LP replacement, and the clinical data were retrospectively analyzed. During the surgery, the patient was supinely placed and the lordosis of the cervical spine was mantained with a pillow placed beneath the neck. Of them, 28 were male and 23 were female, aged 30-64 years (mean, 45 years); 32 were diagnosed as having cervical spondylotic myelopathy, 7 having radiculopathy, and 12 having myelopathy and radiculopathy. The disease duration was 3-48 months (mean, 15 months). CDR was performed at C4, 5 in 5 cases, at C5, 6 in 42 cases, and at C6, 7 in 4 cases. The Cobb angles of the cervical alignment, targeted functional spinal unit (FSU), and targeted disc were measured by sagittal X-ray film of the cervical spine in neutral position before and after surgery, as well as the intraoperative C-arm fluroscopy of the cervical spine. Linear correlation and regression were performed to analyze the relation between cervical Cobb angle difference at intraoperation and improvement of the Cobb angles at 3 months after operation. Results The cervical Cobb angles at intraoperation and 3 months after operation were larger than those at preoperation (P lt; 0.05). The difference of the Cobb angle between intra- and pre-operation was (6.72 ± 9.13)° on cervical alignment, (2.10 ± 5.12)° on targeted FSU, and (3.33 ± 3.75)° on targeted disc. At 3 months after operation, the Cobb angle improvement of the cervical alignment, targeted FSU, and targeted disc was (6.30 ± 7.28), (3.99 ± 5.37), and (4.29 ± 5.36)°, respectively. There was no significant difference in the Cobb angle improvement between the targeted FSU and the targeted disc (t= — 0.391, P=0.698), and between the targeted disc and the cervical alignment (t= — 1.917, P=0.061), but significant difference was found between the targeted FSU and the cervical alignment (t= — 2.623, P=0.012). The linear correlation between the Cobb angle difference and the Cobb angle improvement of the cervical spine was observed (P lt; 0.05). Conclusion A slightly lordotic cervical posture during CDR is an important factor to maintaining normal physiological lordosis of the cervical spine after surgery.
Objective To explore the correlation between the inserting angle of vertebral screws and the extent of post-operative lateral angulation instantly in sugery via anterior approach for thoracolumbar fractures. Methods The cl inical data were from 172 patients consecutively treated with surgery via anterior approach in thoracic and lumbar fractures betweenMay 2004 and January 2008. These cases included 124 males and 48 females at the age of 15-70 years old (mean 39 years old). One fracture were located at T11, 37 at T12, 88 at L1, 30 at L2, 15 at L3, 3 at L4. One segment was involved in 170 cases and two segments in 2 cases. According to Frankel assessment for neurological status, there were 19 cases of grade A, 24 cases of grade B, 45 cases of grade C, 53 cases of grade D, and 31 cases of grade E. The time from injury to operation was 2-30 days (median 8 days). According to the coronal Cobb angle instantly after surgery, the patients were divided into three groups: 0-5° group, 5-10° group and over 10°group. Every group was further divided into four subgroups according to the type of the internal fixation instruments: Z-plate subgroup, Antares subgroup, Profile subgroup and single screw rod (SSR) subgroup. Radiograph images were used to evaluate the coronal Cobb angle and inserting angle between the screws and end-plates. The screws were named as A, B, C and D in vertebral bodies from the cephal ic to the caudal portion. The angles between the superior endplate and the screws A, B were named as angles A, B, and the angles between the inferior endplate and the screws C, D were named as angles C, D. The differences were compared between the screw’s inserting angle A+D (or/and B+C) and the post-operative coronal Cobb angle instantly, and l inear regression analysis was done. The satisfaction survey was acommpl ished. Results Surfacialinfection occurred in 1 patient at 7 days and incision healed well after debridement; other incisions healed by first intention. A total of 172 cases were followed up for 6-49 months (mean 39 months). The degree of satisfaction was 3-10 points, median 8.5 points. Various degrees of neurological function recovered in final follow-up except patients for Frankel A grade. The mean coronal Cobb angles were (0.75 ± 3.91)° for pre-operatively, (3.17 ± 4.07)° for instantly post-operatively and (3.46 ± 4.21)° at last follow-up; showing statistically differences between pre-operatively and instantly post-operatively, between pre-operatively and at last follow-up (P lt; 0.05). Comparing the screw’s inserting angle A+D (or/and B+C) and the coronal Cobb angle, there was statistically significant difference between Z-Plate subgroup and other subgroups in 0-5° group (P lt; 0.05), and there were no statistically significant differences between other subgroups in each group (P gt; 0.05). Except the screw’s inserting angle A+D (Z-Plate and SSR subgroups) and angle B+C (Antares subgroup) in 0-5° group, the post-operative coronal Cobb angle correlated closely with the screw’s inserting angle A+D (or/and B+C) in other subgroups of 3 groups. Conclusion Nonparallel ism between the vertebral screws and the correlative end plate is one of the main causes of post-operative spinal lateral angulation.
Objective To compare the loss of anterior column heightand cervical Cobb angle with three different types of anterior cervical discectomy and fusion(ACDF). Methods A prospective randomized study was performed on 60 patients who had undergone ACDF with the autologous iliac crest graft (group A, n=20), the autogenous bone and the anterior cervical locking plates (group B, n=20), and Syncage-C filled with the local autograft reamings (group C, n=20) from January 1998 to January 2003. The patients diagnosed as having cervical radiculopathy (RP) and cervical spondylotic myelopathy (CSM) were indicated for ACDF. Of the patients, 41 were male and 19 female with a mean age of 57 years (range, 36-68) and their average course of disease was 6.2 months (range, 1-36). There were 36 one-level and 24 two-level fusions from C3,4 to C7,T1. Radiological measurements were performed on the cervical radiographs taken before operation, 7 days and 3 months after operation, and on the last day of the follow-up; then, the height and Cobb angle of the fused segment, functional restoration, and clinical outcome were evaluated in the three groups. Results The followup of more than 2 years (range,2-7) showed that the average loss of anterior column height and Cobb angle of the fused segments in groups A and B, which had not preserved the-endplate, hada greater increase than that in group C, which had preserved the endplate. Of the patients, 12 had autograft collapse, 3 autograft displacement, and 10 postural abnormality between the fused segments, most of which happened in groups A andB. The fusion rate was 93.3% (56 cases) according the strict arthrodesis critera; their excellent and good rate in the functional assessment was 83.3% (RP 90.4%, CSM 79.5%); the overall satisfactory (excellent and good) rates in groups A,B and C were 75%, 85% and 90%, respectively. Conclusion To increase the resistance to graft subsidence, which is a major reason for narrowness of the fused segments, and to maintain normal cervical curvature, we should improve our skills of bone grafting performance, preserve the endplate, carefully evaluate the degree of osteoporosis before operation, and use anterior cervical locking plate and /or fusion with Syncage-C when necessary.
ObjectiveTo investigate the value of smart phone Scoliometer software in obtaining optimal lumbar lordosis (LL) during L4-S1 fusion surgery. MethodsBetween November 2014 and February 2015, 20 patients scheduled for L4-S1 fusion surgery were prospectively enrolled the study. There were 8 males and 12 females, aged 41-65 years (mean, 52.3 years). The disease duration ranged from 6 months to 6 years (mean, 3.4 years). Before operation, the pelvic incidence (PI) and Cobb angle of L4-S1 (CobbL4-S1) were measured on lateral X-ray film of lumbosacral spine by PACS system; and the ideal CobbL4-S1 was then calculated according to previously published methods [(PI+9°)×70%]. Subsequently, intraoperative CobbL4-S1 was monitored by the Scoliometer software and was defined as optimal while it was less than 5° difference compared with ideal CobbL4-S1. Finally, the CobbL4-S1 was measured by the PACS system after operation and the consistency was compared between Scoliometer software and PACS system to evaluate the accuracy of this software. In addition, value of this method in obtaining optimal LL was validated by comparing the difference between ideal CobbL4-S1 and preoperative one with that between ideal CobbL4-S1 and postoperative one. ResultsThe CobbL4-S1 was (36.17±1.53)° for ideal one, (22.57±5.50)° for preoperative one, (32.25±1.46)° for intraoperative one measured by Scoliometer software, and (34.43±1.72)° for postoperative one, respectively. The observed intraclass correlation coefficient (ICC) was excellent [ICC=0.96, 95% confidence interval (0.93, 0.97)] and the mean absolute difference (MAD) was low (MAD=1.23) between Scoliometer software and PACS system. The deviation between ideal CobbL4-S1 and postoperative CobbL4-S1 was (2.31±0.23)°, which was significantly lower than the deviation between ideal CobbL4-S1 and preoperative CobbL4-S1 (13.60±1.85)° (t=6.065, P=0.001). ConclusionScoliometer software can help surgeon obtain the optimal LL and deserve further dissemination.
In order to conduct surface monitoring of the three-dimensional spine morphology of the human body in daily life, a spine morphology measuring method using "single camera, multi-view" to construct stereo vision is proposed. The images of the back of the human body with landmarks of spinous process are captured from multiple angles by moving a single camera, and based on the "Zhang Zhengyou calibration method" and the triangulation principle of binocular stereo vision, the spatial conversion matrices corresponding to each other between all images and the 3D coordinates of the landmarks are calculated. Then the spine evaluation angle used to evaluate the spine morphology is further calculated. The tests’ results showed that the spine evaluation angle error of this method is within ±3°, and the correlation between the results and the X-ray film Cobb angles is 0.871. The visual detection algorithm used in this paper is non-radioactive, and because only one camera is used in the measurement process and there is no need to pre-set the camera's shooting pose, the operation is simple. The research results of this article can be used in a mobile phone-based intelligent detection system, which will be suitable for the group survey of scoliosis in communities, schools, families and other occasions, as well as for the long-term follow-up of confirmed patients. This will provide a reference for doctors to diagnose the condition, predict the development trend of the condition, and formulate treatment plans.