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.
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.
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.
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.
To compare the effectiveness of the operations in treatment of thoracolumber spine fracture and dislocation with spinal cord injury in different periods. Methods Between June 2003 and June 2008, 80 cases of thoracolumber spine fracture and dislocation with spinal cord injury were treated. There were 52 males and 28 females with an average age of 37.6 years (range, 28-49 years). According to different operative time, they were divided into 2 groups by randomized controlled study: group A (n=39, operation was performed within 24 hours) and group B (n=41, operation was performed at 3-7 days). In group A, there were 23 cases of degree I-II (group A1), 16 cases of degree III-V (group A2) according to Meyerding standard, including 17 cases of grade A, 7 cases of grade B, 9 cases of grade C, and 6 cases of grade D according to Frankel scoring system. In group B, there were 21 cases of degree I-II (group B1) and 20 cases of degree III-V (group B2), including 20 cases of grade A, 7 cases of grade B, 11 cases of grade C, and 3 cases of grade D. All cases were treated with posterior spinal cord decompression and reduction, with internal fixation by pedicle screw-rod system and transforamen lumbar interbody fusion. Results The blood loss was (407.4 ± 24.3) mL in group A1 and (397.4 ± 8.2) mL in group B1, showing no significant difference (t=1.804, P=0.078); the blood loss was (1 046.9 ± 128.6) mL in group A2 and (494.4 ± 97.7) mL in group B2, showing significant difference (t=14.660, P=0.000). All 80 patients were followed up 2 years to 2 years and 6 months (mean, 2 years and 3 months) with satisfactory results in spinal cord decompression and reduction, and bony fusion was achieved at 12 months. There was no significant difference in the vertebral canal volume, vertebral height, and Cobb angle at both pre- and postoperation between 2 groups (P gt; 0.05). No loosening or breakage of screws and rods occurred. At 12 months after operation, the cure rates were 47.83% (11/23) in group A1 and 19.05% (4/21) in group B1, showing significant difference (χ2=4.046, P=0.044); the cure rates were 12.50% (2/16) in group A2 and 10.00% (2/20) in group B2, showing no significant difference (χ2=0.056, P=0.813). There was no significant difference (χ2=0.024, P=0.878) in the cure rates in the patients at grades A and B before operation between group A (12.50%, 3/24) and group B (11.11%, 3/27); but there was significant difference (χ2=5.992, P=0.014) in the cure rates in the patients at grades C and D before operation between group A (66.67%, 10/15) and group B (21.43%, 3/14). Conclusion Emergency operation of posterior pedicle screw-rod system for treatment of thoracolumber spine fracture and dislocation with spinal cord injury can provide good reduction, rigid fixation, and high fusion rate, so it is asafe and effective treatment method.
【摘要】 目的 探讨胸腰椎椎弓根钉内固定并发症原因及预防措施。 方法 回顾性分析2006年12月-2010年12月行胸腰椎经椎弓根钉内固定治疗失败的21例患者临床资料。手术均采用经椎弓根钉内固定。误入椎管或穿出椎弓根外壁4例，螺钉断裂4例，定位失误3例；术后1~23个月内固定松动9例，其中术后1~2个月第1次X线片检查发现松动3例，术后1~3个月内固定松动并感染2例；误诊1例（腰椎肿瘤、病理性骨折诊断为骨质疏松骨折）。19例再次手术。 结果 21例均获随访，随访时间3~34个月，平均18.5个月。12例重新固定、植骨融合患者内固定位置良好，未发现内固定松动、断裂或脱出，植骨获得骨性愈合。8例内固定物取出，5例无腰、背部疼痛，腰部活动正常，3例述偶感腰、背部不适，腰部活动尚好，1例感腰、背部疼痛，影响日常活动。1例死亡。 结论 椎弓根螺钉内固定并发症多方面因素引起的，应充分认识，有效的骨折节段融合、术中仔细操作、预防感染、正确的康复锻炼等，可有效减少胸腰椎椎弓根内固定失败。【Abstract】 Objective To discuss the reasons and preventive measures for complications of thoracolumbar pedicle screw fixation. Methods Retrospective analysis of thoracolumbar pedicle screw fixation failure in 21 cases between December 2006 and December 2010 was carried out in this study. The pedicle screw fixation was used in all operations. Straying into the spinal canal or piercing the outer wall of the pedicle during operations happened in 4 cases, screw breakage in 4 cases, and positioning error in 3 cases. Internal fixation was loosened 1 to 23 months after operation in 9 cases, among which 3 were detected at the first X-ray examination 1 to 2 months after operation, 2 were found with infections 1 to 3 months after operation, and 1 was misdiagnosed (spinal tumor with pathological fracture misdiagnosed as osteoporotic fractures). Reoperation was performed for 19 cases. Results All the patients were followed up for 3 to 34 months with an average time of 18.5 months. In the 12 patients who had undergone refixation, the location of the internal fixation was good without loosening, breakage or extrusion, and the grafts obtained bone healing. Internal fixation was removed in 8 patients, among whom 5 had no pain in the waist or back with normal waist activity, and 3 described waist and back discomfort occasionally with fair lumbar activity. One patient felt waist and back pain affecting daily activities. And one patient died. Conclusions Pedicle screw fixation complications are caused by various factors. Fully understanding of the effective integration of the fracture segments, careful intraoperative management, infection prevention, and proper rehabilitation exercises can effectively reduce the thoracic and lumbar pedicle screw failure.
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.
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.
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.