ObjectiveTo investigate the stability of unilateral fractured vertebral pedicle screw fixation in the treatment of thoracolumbar fracture. MethodsEighteen fresh calf thoracolumbar spine specimens (T11-L3) were obtained to establish the L1 burst fracture models with Panjabi's high speed trauma apparatus, and were divided into 3 groups:pedicle fixation for adjacent upper and lower vertebrae of fractured vertebra (4 pedicle screws in group A), combined with pedicle screw fixation for unilateral fractured vertebrae (5 pedicle screws in group B), and three-level 6 pedicle fixation (group C). Under normal, fractured, and reconstructed conditions, the range of motion (ROM) of adjacent upper and lower vertebrae of fractured vertebra were measured in flexion, extension, bilateral bending, and axial rotation. Axial stiffness under flexion-compression was measured on the MTS-858 testing system. ResultsThere was no significant difference in ROM and axial stiffness under normal and fractured conditions in all directions among groups (P<0.05), indicating load balance in the groups. ROM of groups B and C were significantly less than that of group A under reconstructed condition in all directions (P<0.05), but no significant difference was found between group B and group C (P>0.05). Biomechanical test showed that group B was significantly higher than group A in the axial stiffness value (P<0.05), but difference was not significant between group B and group C (P>0.05). ConclusionTranspedicular fixation of fractured vertebrae can enhance the stability of the spine. Both unilateral and bilateral fractured vertebral pedicle screw fixations have the same stability.
Objective To compare the biomechanical properties of the anterior transpedicular screw-artificial vertebral body (AVB) and conventional anterior screw plate system (AP) in lower cervical spine by finite element study. Methods CT images (C1-T1) were obtained from a 38-year-old female volunteer. The models of intact C3-7 (intact group), AP fixation (AP group), and AVB fixation (AVB group) were established and analyzed by Mimics 14.0, Geomagic Studio 2013, and ANSYS 14.0 softwares. The axial force of 74 N and moment couple of 1 N·m were loaded on the upper surface and upper facet joint surfaces of C3. Under conditions of flexion, extension, lateral bending, and rotation, the Von Mises stress distribution regularity and maximum equivalent stree of AP and AVB groups were recorded, and the range of motion (ROM) was also analyzed of 3 groups. Results The intact model of lower cervical spine (C3-7) was established, consisting of 286 382 elements and 414 522 nodes, and it was successfully validated with the previously reported cadaveric experimental data of Panjabi and Kallemeyn. The stress concentrated on the connection between plate and screw in AP group, while it distributed evenly in AVB group. Between AP and AVB groups, there was significant difference in maximum equivalent stress values under conditions of 74 N axial force, flexion, extension, and rotation. AVB group had smaller ROM of fixed segments and larger ROM of adjacent segments than AP group. Compared with intact group, whole ROM of the lower cervical spine decreased about 3°, but ROM of C3, 4 and C6, 7 segments increased nearly 5° in both AP and AVB groups. Conclusion As a new reconstruction method of lower cervical spine, AVB fixation provides better stability and lower risk of failure than AP fixation.
【摘要】 目的 探討CT引導下經椎弓根穿刺活檢對椎體病變的診斷價值及可行性。 方法 回顧性分析2009年5月—2010年4月42例椎體病變患者經椎弓根穿刺活檢的穿刺活檢方法、病理結果、最終診斷及穿刺并發癥。 結果 患者總穿刺準確率為95.2%（40/42）。其中惡性病變的穿刺準確率為94.3%（33/35），良性病變穿刺準確率為100%（7/7）；所有患者均未發生嚴重穿刺并發癥。 結論 CT引導下經椎弓根穿刺活檢診斷椎體病變有安全可靠、準確性高等特點。【Abstract】 Objective To explore the value and the feasibility of CT guided transpedicular biopsy in diagnosing vertebral body lesions. Methods From May 2009 to April 2010, 42 patients with vertebral body lesions underwent CT guided transpedicular biopsy. The clinical data including the puncture method, pahtological resutls, final diagnosis, and the pucture complications were retrospectively analyzed. Results The total accuracy rate of the puncture was 95.2%(40/42). The accuracy rate of the puncture was 94.3% (33/35) for malignant lesions and 100.0% (7/7) for benign lesions. No complication occurred. Conclusion CT guided transpedicular biopsy is very helpful in diagnosing vertebral body lesions with high accuracy and fewer complications.
ObjectiveTo investigate the safety and effectiveness of pedicle screw implantation via vertebral arch-transverse pathway in clinical application by a prospective randomized controlled trial.MethodsTwenty-four patients who were admitted between May 2015 and June 2017 and met the selection criteria for thoracic pedicle screw fixation were included in the study. According to the random number table method, they were divided into the trial group (screw implantation via vertebral arch-transverse pathway) and the control group (traditional screw implantation technology), with 12 patients in each group. There was no significant difference between the two groups in age, gender, cause of injury, injured segment, and the interval between injury and operation (P>0.05). The time of screw implantation was recorded and compared between the two groups. The acceptable rate of screw implantation and the penetration rate of pedicle wall were calculated after operation.ResultsThe time of screw implantation of trial group was (5.08±1.74) minutes, which was significantly shorter than that of control group [(5.92±1.66) minutes], and the difference was significant (t=4.258, P=0.023). Patients in both groups were followed up 1-2 years, with an average of 1.5 years. During the follow-up, no failure of internal fixation occurred. At 1 week after operation, the screw implantation in trial group was rated as gradeⅠin 54 screws, gradeⅡ in 3 screws, and grade Ⅲ in 2 screws, with the acceptable rate of 93.61%. The screw implantation in control group was rated as gradeⅠin 40 screws, grade Ⅱin 10 screws, grade Ⅲ in 8 screws, and grade Ⅳ in 1 screw, with the acceptable rate of 84.75%. There was significant difference in the acceptable rate of screw implantation between the two groups (χ2=3.875, P=0.037). The penetration rate of pedicle wall in trial group was 8.47% (5/59), which was significantly lower than that in the control group [32.20% (19/59); χ2=4.125, P=0.021].ConclusionCompared with the traditional technique, the pedicle screw implantation via vertebral arch-transverse pathway can obtain a good position of the screw canal with higher accuracy and simpler operation.
Objective To analyze the therapeutic effect of the posterior pedicle screw system combined with interbody fusion cage on lumbarspondylolisthesis. Methods From February 2003 to March 2006, 37 lumbar spondylolisthesis patients were treated with this operation, including21 males and 16 females and aging 3969 years.The affected lumbars were L3(3cases)，L4(23 cases), and L5(11 cases). According to the Meyerdingevaluating system, 12 cases were lassified as degree Ⅰ, 20 cases as degree Ⅱ,and 5 cases as degree Ⅲ. Taillard index, Boxall index, slipping angle, lumbar lordosis angle and intervertebral height index were measured before operation, and 2 weeks and 3 months after operation. Results All patients were followed up 336 months. There were statistically significant differences in Taillard index, Boxall index, slipping angle, lumbar lordosis angle and intervertebral height index between before operation and 2 weeks after operation (P＜0.05),and no statistically significant differences between 2 weeks and 3 months afteroperation(P＞0.05). According to Dewei Zhou’s creterior for scoring, the results were excellent in 27 cases， good in 8 cases，and fair in 2 cases. Theexcellent and good rate was 94.6%. All of the embedded osseous were fused. Thefusing time was from 3 to 8 months (mean 3-9 months). There were no breakageof screw and rod. The position and configuration of the whole cages were good. Conclusion Applying the posterior pedicle screw system combined with interbody fusion cage may achieve synergism in the treatment of lumbar vertebral spondylolisthesis. Above procedure is served as solid internal fixationand offers a satisfactory reduction, and can improve the fusion rate of the spine. So it is an ideal procedure and worthily recommended method for treatment oflumbar vertebral spondylolisthesis.
Objective To evaluate the effectiveness of pedicle subtraction osteotomy (PSO) and non-osteotomy techniques in treatment of medium-to-severe kyphoscoliosis by retrospective studies. Methods Between January 2005 and January 2009, 99 patients with medium-to-severe kyphoscoliosis were treated by PSO (PSO group, n=46) and non-osteotomytechnique (non-osteotomy group, n=53) separately. There was no significant difference in sex, age, Cobb angle of scol iosis on coronal plane, and Cobb angle of kyphosis on saggital plane between 2 groups (P gt; 0.05). The operation time and blood loss were recorded; the Cobb angle of scol iosis on coronal plane and kyphosis on sagittal plane were measured at pre- and postoperation to caculate the rates of correction on both planes. Results The operation was successfully completed in all the patients. The operation time and blood loss of the patients in PSO group were significantly greater than those of the patients in non-osteotomy group (P lt; 0.05). All patients were followed up 12-56 months (mean, 22.4 months); no spinal cord injury occurred, and bone fusion was achieved at last follow-up. The Cobb angles of scol iosis and kyphosis at 2 weeks and last follow-up were significantly improved when compared with the preoperative angles in the patients of 2 groups (P lt; 0.05). There was no significant difference in Cobb angle of scol iosis and the rate of correction between 2 groups (P gt; 0.05), but the correction loss of PSO group was significantly smaller than that of non-osteotomy group (P lt; 0.05) at last follow-up. At 2 weeks and last follow-up, the Cobb angle of kyphosis, the rate of correction, and correction loss were significantly better in PSO group than in non-osteotomy group (P lt; 0.05). Conclusion There is no signifcant difference in scol iosis correction between PSO and non-osteotomy techniques.PSO can get better corrective effect in kyphosis correction than non-osteotomy technique, but the operation time and blood losswould increase greatly.
Objective To investigate the effectiveness of transvertebral space and under the pedicle osteotomy for thoracolumbar kyphosis caused by old osteoporotic vertebral compression fracture (OVCF). Methods The clinical data of 11 patients with thoracolumbar kyphosis caused by old OVCF treated by transvertebral space and under the pedicle osteotomy between January 2016 and December 2020 were retrospectively analyzed. There were 2 males and 9 females, with an average age of 61.3 years (range, 50-77 years) and with a median disease duration of 8 years (range, 6 months to 50 years). Fracture reasons: 9 cases had a clear history of trauma, and 2 cases had no obvious incentive. A total of 11 vertebrae was involved in fracture, including T12 in 3, L1 in 7, L2 in 1. The operation time, intraoperative blood loss, postoperative drainage volume, and complications were recorded. Full-length X-ray films of spine and local X-ray films of the operation area were examined before operation, at 7 days after operation, and at last follow-up. The Cobb angle of thoracolumbar kyphosis was measured, and the correction rate was calculated. The visual analogue scale (VAS) score and Oswestry disability index (ODI) were recorded to assess patients’ pain and functional improvement before operation, at 1 month after operation, and at last follow-up. Results All operations were successfully completed. The average operation time was 188.6 minutes (range, 140-215 minutes); the average intraoperative blood loss was 268.2 mL (range, 100-500 mL); the average postoperative drainage volume was 615.5 mL (range, 160-1 500 mL). One patient developed bilateral thigh rebound pain after operation, which relieved after symptomatic treatment of nutritional nerve and acesodyne. All patients were followed up 14.7 months on average (range, 6-56 months). At last follow-up, osseous fusion was observed in all patients, and no fracture, loose, or displacement of internal fixator was observed on imaging. At 7 days after operation and at last follow-up, the Cobb angle of thoracolumbar kyphosis significantly improved when compared with preoperative one (P<0.05), and there was no significant difference between at 7 days after operation and at last follow-up (P>0.05); the correction rates of Cobb angle at 7 days after operation and at last follow-up were 68.0%±9.8% and 60.3%±11.9%, respectively. At 1 month after operation and at last follow-up, the VAS score and ODI significantly improved when compared with preoperative ones, and further improved at last follow-up when compared with those at 1 month after operation, all showing significant differences (P<0.05). ConclusionTransvertebral space and under the pedicle osteotomy is an effective way to treat thoracolumbar kyphosis caused by old OVCF with less trauma, shorter operation time, and less intraoperative blood loss. Patients can obtain good orthopedic results and quality of life.
Objective To explore the feasibility and the effectiveness of the accurate placement of lumbar pedicle screws using three-dimensional (3D) printing navigational templates in Quadrant minimally invasive system. Methods The L1-5 spines of 12 adult cadavers were scanned using CT. The 3D models of the lumbar spines were established. The screw trajectory was designed to pass through the central axis of the pedicle by using Mimics software. The navigational template was designed and 3D-printed according to the bony surface where the soft tissues could be removed. The placed screws were scanned using CT to create the 3D model again after operation. The 3D models of the designed trajectory and the placed screws were registered to evaluate the placed screws coincidence rate. Between November 2014 and November 2015, 31 patients with lumbar instability accepted surgery assisted with 3D-printing navigation module under Quadrant minimally invasive system. There were 14 males and 17 females, aged from 42 to 60 years, with an average of 45.2 years. The disease duration was 6-13 months (mean, 8.8 months). Single segment was involved in 15 cases, two segments in 13 cases, and three segments in 3 cases. Preoperative visual analogue scale (VAS) was 7.59±1.04; Oswestry disability index (ODI) was 76.21±5.82; and the Japanese Orthopaedic Association (JOA) score was 9.21±1.64. Results A total of 120 screws were placed in 12 cadavers specimens. The coincidence rate of placed screw was 100%. A total of 162 screws were implanted in 31 patients. The operation time was 65-147 minutes (mean, 102.23 minutes); the intraoperative blood loss was 50-116 mL (mean, 78.20 mL); and the intraoperative radiation exposure time was 8-54 seconds (mean, 42 seconds). At 3-7 days after operation, CT showed that the coincidence rate of the placed screws was 98.15% (159/162). At 4 weeks after operation, VAS, ODI, and JOA score were 2.24±0.80, 29.17±2.50, and 23.43±1.14 respectively, showing significant differences when compared with preoperative ones (t=14.842,P=0.006;t=36.927,P=0.002;t=–36.031,P=0.001). Thirty-one patients were followed up 8-24 months (mean, 18.7 months). All incision healed by first intention, and no complication occurred. During the follow-up, X-ray film and CT showed that pedicle screw was accurately placed without loosening or breakage, and with good fusion of intervertebral bone graft. Conclusion 3D-printing navigational templates in Quadrant minimally invasive system can help lumbar surgery gain minimal invasion, less radiation, and accurate placement.
Objective To investigate short-term effectiveness of spinal navigation with the intra-operative three-dimensional (3D)-imaging modality in pedicle screw fixation for congenital scoliosis (CS). Methods Between July 2010 and December 2011, 26 patients with CS were treated. Of 26 patients, 13 patients underwent pedicle screw fixation using the spinal navigation with the intra-operative 3D-imaging modality (navigation group), while 13 patients underwent the conventional technique with C-arm X-ray machine (control group). There was no significant difference in gender, age, hemivertebra number and location, major curve Cobb angle, and Risser grade between 2 groups (P gt; 0.05). Operation time, operative blood loss, frequency of the screw re-insertion, and postoperative complication were observed. The pedicle screw position was assessed by CT postoperatively with the Richter’s standard and the correction of Cobb angle was assessed by X-ray films. Results All patients underwent the surgery successfully without major neurovascular complication. There was no significant difference in operation time, operative blood loss, and pedicle screw location between 2 groups (P gt; 0.05). A total of 58 screws were inserted in navigation group, and 3 screws (5.2%) were re-inserted. A total of 60 screws were inserted in control group, and 10 screws (16.7%) were re-inserted. There was significant difference in the rate of pedicle screw re-insertion between 2 groups (χ2=3.975, P=0.046). Patients of navigation group were followed up 6-24 months, and 6-23 months in control group. According to Richter’s standard, the results were excellent in 52 screws and good in 6 screws in navigation group; the results were excellent in 51 screws, good in 5 screws, and poor in 4 screws in control group. Significant difference was found in the pedicle screw position between 2 groups (Z= — 1.992, P=0.046). The major curve Cobb angle of 2 groups at 1 week and last follow-up were significantly improved when compared with preoperative value (P lt; 0.05), but there was no significant difference between 1 week and last follow-up (P gt; 0.05). No significant difference in correction rate of the major curve Cobb angle was found between 2 groups at last follow-up (t=0.055, P=0.957). Conclusion Spinal navigation with the intra-operative 3D-imaging modality can improve the accuracy of pedicle screw implantation in patients with CS, and effectually reduce the rate of screw re-insertion, and the short-term effectiveness is satisfactory.
To analyze the effectiveness of posterior pedicle screw system combined with interbodyfusion in treating lumbar spondylol isthesis. Methods Between January 2005 and January 2009, 26 patients with lumbar spondylol isthesis underwent posterior pedicle screw system combined with interbody fusion, including 11 males and 15 females with an average age of 56.8 years (range, 36-73 years). The disease duration was 7 months to 11 years. The affected lumbars were L3 in 3 cases, L4 in 12 cases, and L5 in 11 cases. According to the Meyerding evaluating system, 21 cases were classified as degree III, 5 cases as degree III-IV, and 1 case as degree IV. The cl inical results were investigated by measuring radiographic measurements, including Taillard index, Boxall index, sl i pping angle, lumbar lordosis angle,and intervertebral height index preoperatively, immediately, 2 weeks and 3 months postoperatively, respectively. SUK’s criteria was used to judge bone graft fusion. Results Primary heal ing of the incisions was achieved in all cases. Allpatients were followed up 25.8 months on average (range, 10-51 months). There were significant differences in Taillardindex, Boxall index, sl i pping angle, lumbar lordosis angle, and intervertebral height index between preoperatively andimmediately, 2 weeks, 3 months after operation (P lt; 0.05). Bone graft fusion was achieved at 3-8 months after operation(mean, 3.5 months); and the fusion rate was 100%. According to Japanese Orthopedic Association (JOA) scoring, theresults were excellent in 17 cases, good in 7 cases, fair in 1 case, and poor in 1 case; and the excellent and good rate was 92.3%. Compl ications occurred in 2 cases, including nail or rod breakage and nerve injury, and they were cured aftertreatment. Conclusion Posterior pedicle screw system combined with interbody fusion treating lumbar vertebralspondylol isthesis can afford sol id internal fixation and achieve a satisfactory reduction, so it maybe an ideal procedure and a worthy recommended method for treating lumbar spondylol isthesis.