Objective To study the changes of blood flow of the already-compressed cauda equina under dynamic burden, high frequency stimulation (HFS) and increased additional compression, and to clarify the mechanism of neurogenic intermittent claudication. Methods Thirty SD rats were divided into 5 groups, 6 in each. All groups were operated with laminectomy of the fifth lumbar verfebra. One hour after the measurement of blood flow,in 4experimental groups, the silicon sheets were inserted into the spinal canal of L4 and L6 to cause double level compression of cauda equina by 30%. Two hours after onset of compression, no dynamic burden was introduced to the subjects of the experimental group 1. Only HFS was introduced to the subjects of the experimental group 2 for 6 minutes. Both HFS and increased additional compression were introduced to the subjects of the experimental group 3 for 6 minutes. While only increased additional compression was introduced to the subjects of the experimental group 4 for 6 minutes. The subjects of control group only underwent laminectomy of the fifth lumbar vertebra and HFS 6 minutes. The blood flow of cauda equina was measured with laser Doppler flowmeter. Results In the first 2 hours, there was no significant change of cauda equina blood flow in the control group. During the time of HFS, the blood flow increased significantly to 186.4%±31.5% of initial value (Plt;0.05). In the experimental group 1, there was no blood flow change during the period of dynamic burden（110.4％±7.5％，Pgt;0.05）. After introduction of dynamic burden, there was no blood flow changes in the experimental group 2 (111.6％±17.6％，Pgt;0.05). The blood flow in the experimental group 3 decreased to 65.3%±10.7% of initial value (Plt;0.05); and the blood flow in the experimental group 4 decreased to 60.1%±9.2% of initial value (Plt;0.01). There was no significant difference between the experimental groups 3 and 4 (Pgt;0.05). Conclusion The results above show that during the period of increased impulse transmission, double level compression of cauda equina may limit the increase of blood flow, which maycause relative ischemia. If there is increased additional compression along with increased impulse transmission, the blood flow will decrease significantly, which will cause absolute ischemia.
Objective To investigate diagnosis and treatment of farlateral lumbar disc herniations. Methods The clinical data from 16 patients with far-lateral lumbar disc herniations from January 1999 to January 2004 were retrospectively analyzed. The CT scanning showed that the shadow density of the CT scanning values in the corresponding intra-foramen, extraforamen and all-foramen was as the same as that of the intervertebral disc. Of the 16 patients, 10 were operated on by the interlaminar approach, 3 were operatedon by the laterolaminar approach, 3 were operated on by the combined interlaminal and laterolaminal approach.Results According to the follow-up for 6 monthsto 5 years, excellent results were obtained in 8 patients, good results in 5, and fair results in 3. The postoperative CT examination showed that the space occupying in the foramen or extraforamen of the corresponding segment vanished and the nerve root compression of the identical segment also vanished. Conclusion The lamellar highresolution CT is a better way to diagnose lumbar disc herniation. The operative approach should be chosen according to the position of the intervertebral disc protrusion, pathologic type, and presence or absence of the lesions in the vertebral canal.
Objective To explore the effectiveness of percutaneous pedicle screw fixation on the indirect reduction of posterosuperior fracture fragment in the thoraculumbar burst fractures. Methods Patients with thoracolumbar fractures treated in the Fourth People’s Hospital of Zigong from September 2017 to September 2019 were collected retrospectively. All patients were treated with percutaneous pedicle screw fixation. The main observation indexes before operation, 3 days after operation and 1 year after operation were compared, including the height ratio of the anterior margin of fractured vertebra, the inversion angle of posterosuperior fracture fragment, the fragment displacement, the occupancy rate of spinal canal, the Cobb angle of kyphosisat, Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI). Results A total of 38 patients were included. All patients were followed up for more than 1 year. During the follow-up period, there were no complications such as nerve injury, incision infection, internal fixation loosening or fracture. The operation time was (91.7±10.4) min, the amount of intraoperative bleeding was (94.3±19.5) mL, and the length of surgical incision was (9.3±1.8) cm. The height ratio of the anterior margin of fractured vertebra, the inversion angle of posterosuperior fracture fragment, the fragment displacement, the occupancy rate of spinal canal, the Cobb angle of kyphosisat 3 days after operation were significantly improved compared with those before operation (P<0.05); the height ratio of the anterior margin of fractured vertebra, the occupancy rate of spinal canal, and the Cobb angle of kyphosisat 1 year after operation were also significantly improved compared with those before operation (P<0.05); the height ratio of the anterior margin of fractured vertebra and the occupancy rate of spinal canalat 1 year after operation were significantly improved than those 3 days after operation (P<0.05), but the Cobb angle of kyphosis 1 year after operation was significantly lost than that 3 days after operation (P<0.05). The VAS score and ODI index 3 days and 1 year after operation were significantly improved compared with those before operation (P<0.05), and the VAS score and ODI index 1 year after operation were improved compared with those 3 days after operation (P<0.05). Conclusion The percutaneous pedicle screw fixation can effectively reduce the retropulsed bone fragment indirectly and restore the Cobb angle of kyphosis of the thoraculumbar burst fractures without neurological deficit, and at the same time reduce the operation time and surgical trauma.
ObjectiveTo investigate the early effctiveness of oblique lateral interbody fusion (OLIF) combined with pedicle screw fixation via small incision Wiltse approach for the treatment of lumbar spondylolisthesis.MethodsBetween January 2016 and December 2016, 21 patients with lumbar spondylolisthesis were treated with OLIF and pedicle screw fixation via small incision Wiltse approach. There were 9 males and 12 females, aged 57-73 years, with an average age of 64.5 years. The disease duration was 24-60 months, with an average of 34.6 months. All cases were spondylolisthesis at L4 (15 cases of degreeⅠ, 6 cases of degreeⅡ); 1 case had vertebral arch isthmus, and 20 cases had spinal stenosis. Japanese Orthopaedic Association (JOA) scoring system was used to evaluate the effectiveness before operation and at last follow-up. Before operation and at 2 days after operation, anteroposterior and lateral X-ray films and CT were taken to measure the sagittal diameter and cross-sectional area of the spinal canal, and calculate the intervertebral height and degree of spondylolisthesis. At 6 months after operation, the intervertebral fusion was evaluated by CT.ResultsThe operation time was 120-180 minutes, with an average of 155 minutes; the intraoperative blood loss was 100-340 mL, with an average of 225.5 mL. One patient had slight injury of lower endplate, 1 patient had numbness of thigh and weakness of hip flexion after operation, 1 patient had sympathetic nerve trunk injury. All the cases were followed up 12-18 months, with an average of 14.3 months. The symptoms of low back pain, leg pain, and numbness of lower limbs significantly relieved after operation, and there was no complication such as protrusion of fusion cage, screw breakage, and endplate collapse. At 2 days after operation, the intervertebral height, degree of spondylolisthesis, sagittal diameter of spinal canal, and cross-sectional area of spinal canal significantly improved compared with preoperative ones (P<0.05). At 6 months after operation, CT showed that 1 patient had poor interbody fusion (grade Ⅲ), the other 20 patients had good interbody fusion (grade Ⅰ and Ⅱ), and the interbody fusion rate was 95.2%. At last follow-up, JOA score of lumbar spine significantly increased compared with that before operation (t=24.980, P=0.000).ConclusionOLIF combined with pedicle screw fixation via small incision Wiltse approach for the lumbar spondylolisthesis has minimally invasive features, such as less trauma, fewer complications, and higher intervertebral fusion rate. It is a safe and effective method.
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.
Lumbar spondylolisthesis is a common condition in spinal surgery, which is often characterized by lower back and leg pain and numbness. There are various treatment methods for this condition, and different treatment plans should be adopted according to different situations. Traditional open surgery methods are relatively traumatic and have longer recovery times, while minimally invasive spine techniques have advantages such as smaller incisions, less bleeding, higher fusion rates, and faster recovery. This review summarizes the relevant literature on the application of minimally invasive techniques in the treatment of lumbar spondylolisthesis in recent years, analyzes and compares the advantages and disadvantages of different approaches and endoscopic techniques, as well as reduction, decompression, and fusion effects. The aim is to provide reference for surgeons in selecting surgical procedures for the treatment of lumbar spondylolisthesis.
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.
