ObjectiveTo investigate reliability and short-term effectiveness of axis laminar screws for reducible atlantoaxial dislocation (RAAD).MethodsA clinical data of 41 patients with RAAD who were admitted between February 2013 and February 2018 and met the inclusion criteria was retrospectively analyzed. The atlases in all patients were fixated by lateral mass screws, and the axes were fixed by laminar screws in 13 cases (LS group) and by pedicle screws in 28 cases (PS group). There was no significant difference in gender, age, and preoperative Japanese Orthopedic Association (JOA) score between the two groups (P>0.05). The effectiveness was estimated by post-operative JOA score; and the accuracy of the axis screw, atlantoaxial bone graft fusion, and the fixation stability were examined by X-ray film and CT.ResultsAll incisions healed by first intention. All patients were followed up 12-17 months (mean, 13.8 months) in LS group and 12-20 months (mean 14.1 months) in PS group, and the difference in follow-up time was not significant (Z=−0.704, P=0.482). At last follow-up, JOA scores were 13.9±1.6 in LS group and 14.3±1.8 in PS group, which significantly improved when compared with the pre-operative scores in the two groups (t=−9.033, P=0.000; t=−15.835, P=0.000); while no significant difference was found between the two groups (t=−0.630, P=0.532). Twenty-five screws of 26 screws in LS group and 54 screws of 56 screws in PS group were implanted accurately, with no significant difference in the accuracy of the axis screw between the two groups (Z=−0.061, P=0.951). All patients obtained atlantoaxial bone graft fusion, except 1 case in PS group. There was no significant difference in the atlantoaxial bone graft fusion between the two groups (Z=−0.681, P=0.496).ConclusionFor RAAD, Axis laminar screws can maintain the atlantoaxial primary stability and had a good short-term effectiveness. So, it could be an alternative and reliable technique for axis screw.
Objective To biomechanically compare the maximum pull-out strengths among two pedicle screws and three salvage techniques using poly methylmethacrylate (PMMA) augmentation in osteoporotic sacrum, and to determine which PMMA augmentation technique could serve as the salvage fixation for loosening sacral pedicle screws. Methods Eleven sacra were harvested from fresh adult donated cadavers, aged from 66 to 83 years (average 74.4 years) and included 5 men and 6 women. Radiography was used to exclude sacra that showed tumor or inflammatory or any other anatomic abnormal ities. Following the measurement of bone mineral density, five sacral screw fixations were sequentially establ ished on the same sacrum as follows: unicortical pedicle screw (group A), bicortical pedicle screw (group B), unicortical pedicle screw with the traditional PMMA augmentation (group C), ala screw with the traditional PMMA augmentation (group D), and ala screw with a kyphoplasty-assisted PMMA augmentation technique (group E). According to the sequence above, the axial pull-out test of each screw was conducted on a MTS-858 material testing machine. The maximum pull-out forces were measured and compared. The morphologies of PMMA augmented screws after being pulled-out were also inspected. Results The average bone mineral density of 11 osteoporotic specimens was (0.71 ± 0.08) g/cm2 . By observation of the pull-out screws, groups C, D, E showed perfect bonding with PMMA, and group E bonded more PMMA than groups C and D. The maximum pull-out forces of groups A, B, C, D, and E were (508 ± 128), (685 ± 126), (846 ± 230), (543 ± 121), and (702 ± 144) N, respectively. The maximum pull-out strength was significantly higher in groups B, C, and E than in groups A and D (P lt; 0.05), and in group C than in groups B and E (P lt; 0.05). There was no significant difference in pull-out strength between groups A and D, and between groups B and E (P gt; 0.05). Conclusion For sacral screw fixation of osteoporotic patients with bone mineral density more than 0.7 g/cm2, bicortical pedicle screw could acquire significantly higher fixation strength than the unicortical. Once the loosening of pedicle screw occurs, the traditional PMMA augmentation or ala screw with kyphoplasty-assisted PMMA augmentation may serve as a suitable salvage technique.
ObjectiveTo investigate the effectiveness of debridement and single-incision vertebral screw-rod fixation combined with pedicle screw-rod fixation and autograft bone fusion in treatment of thoracolumbar tuberculosis. MethodsBetween January 2008 and October 2010, 22 patients with thoracolumbar tuberculosis were treated by debridement and single-incision vertebral screw-rod fixation combined with pedicle screw-rod fixation and autograft bone fusion, and were given anti-tuberculosis therapy after operation. Of 22 patients, 14 were male and 8 were female with an average age of 42 years (range, 18-66 years). The disease duration was 2-16 months (mean, 6 months). Sixteen double-segment lesions included T7, 8 in 3 cases, T8, 9 in 1 case, T9, 10 in 3 cases, T11, 12 in 2 cases, L1, 2 in 4 cases, and L3, 4 in 3 cases; 6 three-segment lesions included T7-9 in 2 cases, T11-L1 in 1 case, and L2-4 in 3 cases. Preoperative visual analogue scale (VAS) score was 7.50 ± 0.63. According to Frankel classification of America Spinal Injury Association (ASIA), 2 cases were rated as grade B, 4 cases as grade C, 9 cases as grade D, and 7 cases as grade E. ResultsTwenty-two patients were followed up 15-36 months (mean, 25.2 months). Wound infection occurred in 1 case and was cured after corresponding treatment; incision healed by first intention in other patients. No loosening or breakage of internal fixator was found; the patients had no deteriorations in spinal cord injury or cerebrospinal fluid leakage. X-ray films and CT showed obvious bone fusion in the intervertebral space. The time of bone fusion was 3-6 months (mean, 5.2 months). The erythrocyte sedimentation rate after operation was significantly lower than that before operation (P lt; 0.05). The VAS scores were significantly improved to 2.90 ± 1.00 at 2 weeks after operation and 2.60 ± 0.81 at last follow-up (P lt; 0.05). At last follow-up, nerve function was significantly improved. According to Frankel classification, 2 cases were rated as grade C, 5 cases as grade D, and 15 cases as grade E. ConclusionSingle-incision vertebral screw-rod fixation combined with pedicle screw-rod fixation for thoracolumbar tuberculosis is a stable and minimally invasive method. However, the long-term effectiveness need further follow-up.
Objective To assess the outcomes of pedicle subtration osteotomy and short-segment pedicle screw internal fixation in kyphosisdeformity. Methods From June 2001 to November 2003, 16 cases of kyphosis deformity were treated with pedicle subtration osteotomy and short-segment pedicle screw internal fixation, including 11 males and 5 females and aging 24-51 years. The kyphosis deformity was caused by ankylosing spondylitis in 12 cases, old lumbothoracic fracturedislocation in 2 cases, and vertebral dysplasia in 2 cases. The disease course was 7-25 years with an average of 12.8years. The whole spine radiographs were taken pre-and postoperatively. The sagittal balance was assessed by measuring thoracic kyphosis angle, lumbar lordosis angle, acrohorizontal angle and distance between posterosuperior point of S1and the vertical line. The clinical outcomes were assessed by Bridwell-Dewald scale for spinal disorders. Results The mean follow-up period was25.6 months. The mean bleeding was 1 100 ml. Satisfactory bone graft healing was achieved at final follow-up. Complications were paralytic intestinal obstruction in 1 case, dura laceration in 1 case, and temporary lower limb paralysis in 2 cases. Final follow-up radiograph showed an increase in lumbar lordosis angle from 9.6±16.4° to 42.6±14.3°(P＜0.05), whereas thoracic kyphosis angle remained relative stable. The distance between posterosuperior point of S1 and the vertical line was decreased from 97.5±45.6 mm to 10.7±9.6 mm(P＜0.05). Satisfactory clinical outcome was achieved by evaluating the changes of pain, social and working status. Conclusion Pedicle subtraction osteotomy and short-segment pedicle screw internal fixation is effective for correction of kyphosis deformity.
OBJECTIVE: To review the anatomic character of lower cervical pedicle, the placement and the biomechanical stability of the cervical pedicle screw fixation, the clinical application and the complication caused by fixation. METHODS: The literature concerned the cervical pedicle screw fixation in recent years were extensively reviewed. RESULTS: The cervical pedicle screw fixation can be widely used in the lower cervical spine instability according to the anatomic character of lower cervical pedicle, and the good biomechanical stability of the cervical pedicle screw fixation, and the complication can be controlled. CONCLUSION: The cervical pedicle screw fixation is an effective internal fixation for the lower cervical spine instability.
目的 评价微创椎弓根钉内固定技术治疗胸腰椎爆裂骨折的中期临床疗效。 方法 2002年9月－2007年9月，采用微创椎弓根钉内固定技术治疗胸腰椎爆裂骨折30例。其中男16例，女14例;年龄18～65岁，平均39.8岁。骨折节段:胸11者3例， 胸12者13例， 腰1者12例， 腰者22例。所有骨折按AO分型，均为A3型。受伤至手术时间6 h～6 d，平均45 h。分析术后影像学指标、疼痛评分及功能障碍指数。 结果 患者均获随访，随访时间3～9年，平均5.2年。术后各时间点伤椎前缘高度及后凸Cobb角均较术前明显恢复（P＜0.01）。术后伤椎高度随随访时间延长逐渐下降，后凸Cobb角逐渐增大。取出内固定物后、术后2年、末次随访时动力位X线片上骨折椎体前后相对滑移距离分别为（1.9 ± 0.3）、（2.1 ± 0.2）、（2.1 ± 0.3）mm，两两比较差异无统计学意义（P＞0.05）。术后1、2年及末次随访时疼痛视觉模拟评分分别为（2.5 ± 1.2）、（2.5 ± 1.1）、（2.4 ± 1.3）分，两两比较差异无统计学意义（P＞0.05）。末次随访时Denis腰痛分级：P1级13例，P2级12例，P3级5例。功能障碍指数为（11.4 ± 3.1）分，获优23例、良5例、可2例。 结论 单纯微创椎弓根钉内固定技术治疗胸腰椎爆裂骨折中期临床效果满意，脊柱稳定性良好。Objective To mid-term efficacy of the technique of minimally invasive pedicle screw fixation on thoracolumbar burst fracture. Methods From September 2002 to September 2007, 30 patients were treated with minimally invasive pedicle screw fixation for thoracolumbar fracture. There were 16 males and 14 females with the mean age of 39.8 years (range,18-65 years). The injured level of was T11 in 3 cases, T12 in 13 cases, L1 in 12 cases, and L2 in 2 cases. The type of thoracolumbar fractures of all the patients was A3 according to AO classification. The during from injury to operation was 6 hours to 6 days with an average of 45 hours. The index of image and pain and disability index were evaluated after operation. Results All patients were followed up for 3 to 9 years with the mean of 5.2 years. Their average sliding distance after operation for removing internal fixation was (1.9 ± 0.3), and (2.1 ± 0.2) mm 2 years after the operation and (2.1 ± 0.3) mm at the latest follow-up. There was no significant difference (P＞0.05). Their average score was (2.51 ± 1.2) 1 year after the operation, was (2.42 ± 1.1) 2 year after the operation, and was (2.36 ± 1.3) at the latest follow-up (P＞0.05). According to Denis score system to evaluate index of lumbago, there was P1 in 13 cases, P2 in 12 cases, and P3 in 5 cases. The score of Oswestry Disability Index (ODI) was 11.4 ± 3.1 at the latest follow-up. Twenty-one cases gotexcellent therapeutic result, five cases got good and two were moderate. Conclusions Minimally invasive pedicle screw fixation for the treatment of thoracolumbar burst fracture provide satisfactory clinical results. The vertebral body and adjacent vertebral body have a good stability.
目的 探讨经伤椎椎弓根螺钉内固定治疗胸腰椎骨折的临床疗效。 方法 2008年5月－2010年12月，选择38例胸腰椎骨折患者，采用椎弓根螺钉固定伤椎及相邻上下椎体。其中男28例，女10例；年龄21～65岁，平均36.5岁。骨折部位：胸8 1例，胸9 2例，胸10 4例，胸11 8例，胸12 7例，腰1 10例，腰2 4例，腰3 2例。受伤至手术时间3～7 d，平均4.5 d。对患者手术前后椎体高度、矢状面后凸Cobb角、神经功能Frankel分级变化等指标进行测量并随访。 结果 术后患者切口均Ⅰ期愈合。38例获随访12～18个月，平均15个月。骨折均获得骨性融合，无钉棒断裂、无死亡或神经损伤加重患者。术后神经功能Frankel分级较术前有明显改善（P＜0.05）。术后X线片复查示伤椎高度恢复达90%以上，外形正常；CT复查示椎管内有效矢状径恢复满意，椎管前方无明显骨性压迫，伤椎椎体骨愈合良好。术后1、12个月时伤椎前、后缘高度及后凸Cobb角均较术前显著改善（P＜0.05）；术后12个月随访椎体高度无丢失。 结论 经伤椎椎弓根钉复位、减压、内固定治疗胸腰椎骨折具有创伤小、固定节段少、脊柱稳定性好、能有效矫正及预防脊柱后凸畸形等优点。
ObjectiveTo explore the feasibility and effectiveness of unilateral pedicle screw rod and single poly (ether-ether-ketone) (PEEK) Cage for lumbar intervertebral disc protrusion. MethodsA total of 126 cases of single segment of lumbar intervertebral disc protrusion between January 2006 and June 2012 were divided into 2 groups in the randomized clinical trial. Unilateral pedicle screw fixation and single PEEK Cage was used in 63 cases (research group), and bilateral pedicle screw fixation and single PEEK Cage in 63 cases (control group). There was no significant difference in gender, age, disease duration, side, and affected segment between 2 groups (P>0.05). Schulte evaluation criterion was used to assess bone graft fusion, Oswestry disability index (ODI) to estimate the quality of life situation, and visual analogue scale (VAS) to evaluate the improvements of lower back pain. Macnab standards was applied to assess postoperative effectiveness, and Emery ways to measure the height of intervertebral space. ResultsThe incision length, operation time, intraoperative blood loss, hospitalization time, and hospitalization fee in research group were significantly less than those in control group (P<0.05). The patients were followed up 12-79 months (mean, 21.3 months) in research group, and 15-73 months (mean, 22.6 months) in control group. The postoperative lordosis was recovered well, and the height of intervertebral space was increased. No loosening or breakage of internal fixation occurred. The time of bone graft fusion was (6.8±1.3) months in research group and was (7.1±1.2) months in control group, showing no significant difference (t=1.153, P=0.110). The height of intervertebral space, ODI score, and VAS score were significantly improved when compared with preoperative ones in 2 groups (P<0.05), but no significant difference was found between 2 groups at preoperation and last follow-up (P>0.05). At 3 months after operation, postoperative effectiveness was assessed according to Macnab criterion, the excellent and good rate was 95.23% in research group (excellent in 13 cases, good in 47 cases, and fair in 3 cases) and was 71.42% in control group (excellent in 7 cases, good in 38 cases, fair in 15 cases, and poor in 3 cases); the research group was significantly superior to control group (χ2=6.110, P=0.006). ConclusionUnilateral pedicle screw fixation and single PEEK Cage has the advantages of small trauma, reliable fixation, shorter operation time, less bleeding, less economic cost, and early off-bed activity time. It can provide a simple and reliable choice in single segmental lumbar intervertebral disc protrusion.
ObjectiveTo investigate the effectiveness of cervical pedicle screw implantation technique under regional method.MethodsThe clinical data of 85 patients who met the selection criteria between April 2010 and May 2018 were retrospectively analyzed. There were 57 males and 28 females, aged 35-68 years, with an average of 57.6 years. Among them, there were 10 cases of ossification of posterior longitudinal ligament, 68 cases of cervical spondylosis with multilevel stenosis, 3 cases of cervical tumor, 1 case of congenital malformation, and 3 cases of cervical trauma; the lower cervical spine lesions involved C3-C7. Preoperative Frankel spinal cord injury grading: 2 cases of grade C, 51 cases of grade D, and 32 cases of grade E. Cervical pedicle screw implantation technique under regional method was performed with a total of 618 pedicle screws. Postoperative changes in neurological symptoms were observed; cervical mouth opening anteroposterior and lateral X-ray films and cervical CT examinations were performed to evaluate the pedicle screws position.ResultsThe operation time was 2.5-4.0 hours, with an average of 3.0 hours. The intraoperative blood loss was 180-550 mL, with an average of 345 mL. No intraoperative vascular or nerve injury occurred. The patients with neurological symptoms were relieved to varying degrees. There were 2 cases of superficial incision infection after operation, the wound healed after enhanced dressing change. The postoperative hospital stay was 5-14 days, with an average of 8.4 days. At discharge, Frankel neurological grading was grade D in 26 patients and grade E in 59 patients. All the patients were followed up 6-24 months, with an average of 13 months. At last follow-up, cervical X-ray films showed the good pedicle screw fixation without loosening. Cervical CT evaluated the position of pedicle screws: 523 pedicle screws (84.7%) in grade Ⅰ, 80 (12.9%) in grade Ⅱ, and 15 (2.4%) in grade Ⅲ; the accuracy rate of the screw position was 97.6%.ConclusionCervical pedicle screw implantation technique under regional method can significantly improve the success rate of screw implantation. It is easy to operate, does not destroy the bone cortex, and has stable fixation.
Objective To evaluate the effectiveness of posterior unilateral pedicle screw fixation plus lumbar interbody fusion in treatment of degenerative lumbar instability. Methods Between February 2008 and December 2011, 33 patients with degenerative lumbar instability were treated with posterior unilateral pedicle screw fixation plus lumbar interbody fusion, including 14 cases of lumbar disc protrusion with instability, 15 cases of lumbar spinal stenosis with instability, 3 recurrent cases of lumbar disc protrusion at 1 year after discectomy, and 1 case of extreme lateral lumbar disc protrusion. There were 20 males and 13 females with an average age of 47.2 years (range, 39-75 years). The average disease duration was 12.8 months (range, 6-25 months). Single-segment-fixation was performed in 28 cases (L4, 5 in 21 cases, L5, S1 in 6 cases, and L5, 6 in 1 case), and double-segment-fixation was performed in 5 cases (L3, 4 and L4, 5). The clinical results were evaluated by using Oswestry disability index (ODI) and modified Japanese Orthopaedic Association (JOA) score for low back pain. Results Infection occurred in 1 case, and was cured after dressing change; primary healing was obtained in the other patients. Thirty-one patients were followed up 32.3 months on average (range, 15-53 months). Cage displacement occurred in 1 case who received bilateral pedicle screw fixation plus lumbar interbody fusion; no screw breaking, Cage displacement, or pseudoarthrosis was observed in the others. X-ray films showed bone fusion in the other patients except 1 case of bone fusion failure. ODI and JOA score at last follow-up were significantly improved when compared with the ones before operation and at 2 weeks after operation (P lt; 0.05); the improvement rates were 74.0% ± 10.1% and 83.6% ± 9.4%, respectively. Conclusion Posterior unilateral pedicle screw fixation plus lumbar interbody fusion is an effective and reliable method for patients with degenerative lumbar instability because it has the advantages of simple operation and less trauma.