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 observe the early effectiveness of cervical disc replacement with Pretic-I, a new type artificial disc. Methods A retrospective analysis was made on the clinical data of 10 patients who underwent single segmental cervical disc replacement with Pretic-I from June to December 2014. Among 10 patients, 4 were male and 6 were female, with an average age of 40 years (range, 27-51 years). The mean disease duration was 15.4 months (range, 4-36 months). Affected segments located at C4, 5 level in 1 case, at C5, 6 level in 8 cases, and at C6, 7 level in 1 case. The visual analogue scale (VAS), Japanese Orthopaedic Association (JOA) score, and neck disability index (NDI) were used to evaluate the clinical outcomes. Besides, the disc height and the range of motion (ROM) at operated level, and ROM of upper and lower adjacent level were measured to assess the function. Results The operation was successfully completed in all patients who were followed up for 12 months. No complications of aggravated nerve symptoms, vertebral artery injury, esophagotracheal fistula, cerebrospinal fluid leakage, incision infection, hematoma and prosthetic loosening were observed during follow-up. The VAS score, JOA score, and NDI significantly improved at each time point after operation when compared with preoperative scores (P<0.05). The height of intervertebral disc at operated level was significantly increased at immediate and 3 months after operation when compared with preoperative one (P<0.05), but no significant difference was found between at 6 months or 12 months after operation and at pre-operation (P>0.05). No significant difference was shown in the ROM at operated level, and ROM of upper and lower adjacent level between at pre-operation and at each time point after operation (P>0.05). Conclusion The early effctiveness of cervical disc replacement using Pretic-I is satisfactory. The symptoms can be relieved significantly and the dynamic features of the operated level, as well as the upper and lower adjacent levels, are well preserved.
ObjectiveTo measure anatomical parameters related to cervical uncovertebral joint and provide data support for the design of uncovertebral joint fusion cage.MethodsAccording to the inclusion and exclusion criteria, raw DICOM data of cervical CT scan in 60 patients (30 males and 30 females, aged 39-60 years) were obtained, then the three-dimensional cervical spine model was reconstructed for anatomical measurement by using the Mimics19.0 software. The height of the uncinate process, the length of the uncinate process, the width of the uncinate process, and the length of the uncovertebral joint in the intervertebral foramen region were measured bilaterally from C3 to C7. The anterior and posterior distances between the uncinate processes were measured from C3 to C7. The height of the uncovertebral joint space, the central height of the intervertebral disc space, and the depth of the intervertebral disc space were also measured from C2, 3 to C6, 7. The mean, standard deviation, maximum, and minimum were calculated by using the SPSS22.0 statistical software for the design of uncovertebral joint fusion cage.ResultsThe height of the uncinate process, the length of the uncinate process, the width of the uncinate process, and the length of the uncovertebral joint in the intervertebral foramen region of C3-C7 and the height of the uncovertebral joint space of C2, 3-C6, 7 showed no significant difference between two sides (P>0.05). The height of the uncovertebral joint space also had no significant difference between females and males (P>0.05). The anterior distances between the uncinate processes of C3-C7 were significantly larger than the posterior distances between the uncinate processes (P<0.05), the uncovertebral joint presented a posterior cohesive shape. The central height of the intervertebral disc space in male group was slightly higher than that in female group, and the differences were significant (P<0.05) at C2, 3 and C5, 6; the depth of the intervertebral disc space in male group was significantly higher than that in female group (P<0.05). The central height of the intervertebral disc space was (4.94±0.49) mm (range, 3.81-5.90 mm), the depth of the intervertebral disc space was (15.78±1.23) mm (range, 12.94-18.85 mm), the anterior and posterior distances between the uncinate processes were (17.19±2.39) mm (range, 13.39-24.63 mm) and (10.84±2.12) mm (range, 7.19-16.64 mm), respectively. According to the results of the anatomical research, the height of the uncovertebral joint fusion cage was designed as 5, 6, 7, and 8 mm; the depth of the uncovertebral joint fusion cage was designed as 12, 13, 14, 15, and 16 mm; the width of the uncovertebral joint fusion cage was designed as 14-18 mm; and the two wings are designed as arc-shape with 2 and 3 mm in width.ConclusionThere are certain differences in the anatomical parameters of the uncovertebral joint between different segments. The uncovertebral joint fusion cage that designed based on the results of anatomical research is suitable for most patients.
Objective To develop a deep learning system for CT images to assist in the diagnosis of thoracolumbar fractures and analyze the feasibility of its clinical application. Methods Collected from West China Hospital of Sichuan University from January 2019 to March 2020, a total of 1256 CT images of thoracolumbar fractures were annotated with a unified standard through the Imaging LabelImg system. All CT images were classified according to the AO Spine thoracolumbar spine injury classification. The deep learning system in diagnosing ABC fracture types was optimized using 1039 CT images for training and validation, of which 1004 were used as the training set and 35 as the validation set; the rest 217 CT images were used as the test set to compare the deep learning system with the clinician’s diagnosis. The deep learning system in subtyping A was optimized using 581 CT images for training and validation, of which 556 were used as the training set and 25 as the validation set; the rest 104 CT images were used as the test set to compare the deep learning system with the clinician’s diagnosis. Results The accuracy and Kappa coefficient of the deep learning system in diagnosing ABC fracture types were 89.4% and 0.849 (P<0.001), respectively. The accuracy and Kappa coefficient of subtyping A were 87.5% and 0.817 (P<0.001), respectively. Conclusions The classification accuracy of the deep learning system for thoracolumbar fractures is high. This approach can be used to assist in the intelligent diagnosis of CT images of thoracolumbar fractures and improve the current manual and complex diagnostic process.