Cortical screw placement with a spinous process clamp guide: a cadaver study accessing accuracy.

BACKGROUND AND OBJECTIVE: The Cortical Bone Trajectory (CBT) technique provides an alternative method for fixation in the lumbar spine in patients with osteoporosis. An accuracy CBT screw placement could improve mechanical stability and reduce complication rates. PURPOSE: The purpose of this study is to explore the accuracy of cortical screw placement with the application of implanted spinous process clip (SPC) guide. METHODS AND MATERIALS: Four lumbar specimens with T12-S1 were used to access the accuracy of the cortical screw. The SPC-guided planning screws were compared to the actual inserted screws by superimposing the vertebrae and screws preoperative and postoperative CT scans. According to preoperative planning, the SPC guide was adjusted to the appropriate posture to allow the K-wire drilling along the planned trajectory. Pre and postoperative 3D-CT reconstructions was used to evaluate the screw accuracy according to Gertzbein and Robbins classification. Intraclass correlation coefficients (ICCs) and Bland-Altman plots were used to examine SPC-guided agreements for CBT screw placement. RESULTS: A total of 48 screws were documented in the study. Clinically acceptable trajectory (grades A and B) was accessed in 100% of 48 screws in the planning screws group, and 93.8% of 48 screws in the inserted screws group (p = 0.242). The incidence of proximal facet joint violation (FJV) in the planning screws group (2.1%) was comparable to the inserted screws group (6.3%) (p = 0.617). The lateral angle and cranial angle of the planned screws (9.2 ± 1.8° and 22.8 ± 5.6°) were similar to inserted screws (9.1 ± 1.7° and 23.0 ± 5.1°, p = 0.662 and p = 0.760). Reliability evaluated by intraclass correlation coefficients and Bland-Altman showed good consistency in cranial angle and excellent results in lateral angle and distance of screw tip. CONCLUSIONS: Compared with preoperative planning screws and the actually inserted screws, the SPC guide could achieve reliable execution for cortical screw placement.

The accuracy of cortical bone trajectory screw placement guided by spinous process clamp hardware in lumbar spinal surgery: a retrospective study.

This study aimed to assess the accuracy of cortical bone trajectory (CBT) screws placement guided by a spinous process clamp (SPC) guide. A total of 32 patients who received single-level midline lumbar fusion (MIDLF) surgery between June 2019 and January 2020 were retrospectively analyzed and divided into free-hand (FH) and SPC-guided groups according to the surgical approach. In the FH group, CBT screws was implanted with the assistance of fluoroscopy, while in the SPC group, CBT screws was implanted using the SPC navigator hardwire. A total of 128 screws were assessed in this study, with higher rates of clinically acceptable screw placement (grades A and B) and grade A screws in the SPC group than in the FH guide group (92.2% vs. 79.7%, P = 0.042 and 54.7% vs. 35.9%, P = 0.033, respectively). Misplacement screws (grades C, D, and E) occurred more often in the FH group than in the SPC guide group (20.3% vs. 7.8%, P = 0.042). The incidence of proximal facet joint violation (FJV) was higher in the FH group than in the SPC group (15.6% vs. 3.1%, P = 0.030). The radiation dose and time in the SPC guide group were comparable to those in the FH group (P = 0.063 and P = 0.078). The average operative time was significantly longer in the SPC guide group than in the FH group (267.8 ± 45.5 min vs. 210.9 ± 44.5 min, P = 0.001). Other clinical parameters, such as the average bone mineral density (BMD), intraoperative blood loss, and postoperative hospital stay, were not significantly different. Oswestry disability index (ODI) and back pain visual analogue scale (VAS) scores were significantly improved in both groups compared with preoperatively. SPC guided screw placement was more accurate than the fluoroscopy-assisted FH technique for single-level MIDLF at L4/5. Patients undergoing SPC-guided screw placement can achieve similar clinical outcomes as the fluoroscopy-assisted FH technique.

Accuracy of cortical bone trajectory screw fixation guided by spinous process clamp guide in lumbosacral vertebrae: A cadaver study.

BACKGROUND: The purpose of this study was to access the accuracy of cortical bone trajectory screw placement guided by spinous process clamp (SPC). METHODS: Eight formalin-treated cadaveric lumbar specimens with T12-S1 were used. A total of 96 screws were implanted in eight lumbar specimens. RESULTS: In the freehand (FH) group, clinically acceptable placement (grade A and B) was 40 screws (83.3%), meanwhile 44 screws (91.7%) in the SPC guide group (p = 0.217). The grade A screws in the SPC guide group were much more than that in the FH group (n = 40 vs. n = 31, p = 0.036). The misplacement screws (grade C, D, and E) and proximal facet joint violation (FJV) in the SPC group was comparable to the FH group. CONCLUSIONS: This cadaveric study demonstrate that implanting CBT screws guided by SPC guide was more accuracy and reduces severe deviations in important directions.

[Device implanted complications of Coflex interspinous dynamic stabilization].

OBJECTIVE: To investigate device implanted complications and corresponding therapeutic strategies of Coflex interspinous dynamic stabilization system for lumbar spine intraoperatively and postoperatively. METHODS: From September 2008 to August 2010, 133 cases of degenerative disease of lumbar spine including 62 males and 71 females, ranging from 35 to 81 years of age (mean 60.8 years), underwent or planed to be underwent decompression with Coflex interspinous dynamic stabilization system were reviewed retrospectively, and 13 cases including 6 males and 7 females, ranging from 41 to 71 years of age (mean 58.6 years), occurred device implanted complications. The Coflex implanted complications were analyzed, and therapeutic strategies according to different character were carried out, scores of visual analogue scale (VAS), Oswestry disability index(ODI) and effect-related data preoperatively, postoperatively, after conservative treatment and in final follow-up were evaluated with paired-samples t test. RESULTS: Thirteen cases of Coflex implanted complications and treatment applied included: 3 cases occurred fracture of spinous processes intraoperatively were treated by pedicle screws instead; 2 cases occurred fracture of spinous processes postoperatively or during follow-up, including 1 case underwent revision with pedicle screws, another 1 case treated with conservative treatment; 4 cases with degenerative coronal spondylolysis in surgical segments, 1 case with sagittal instability preoperatively, and 1 case with device dislodgment in follow-up all suffered aggravated pain and received conservative treatment; 1 case suffered implanted malposition intraoperatively was underwent internal fixation with pedicle screws instead; at length, 1 case with aggravated pain postoperatively and without definite reason received revision with internal fixation of pedicle screws demolishing the Coflex. The follow-up time of 13 cases ranged from 20 to 38 months (mean 27.6 months); and 7 cases implanted Coflex with aggravated pain of lumbar and lower limb, but the position of device can still maintained, were received conservative treatment, and whose score of VAS and ODI in the final follow-up were 1.9 ± 0.7 and 23.2 ± 3.4, and comparing to 6.1 ± 1.1 and 58.1 ± 3.0 preoperatively, evident improvement was got finally (t = 8.2 and 18.2, P < 0.01). Scores of VAS and ODI of 2 cases with Coflex implanted complications underwent revision with pedicle screws were also improved correspondingly. CONCLUSIONS: Coflex interspinous dynamic stabilization system implanted should be avoided to cases who suffered with osteoporosis, too narrow interspinous space and intervertebral coronal spondylolysis or sagittal instability; and choice of device, depth of implantation and intensity of clumping should be appropriate. For patients with symptom but device still in right position, conservative treatment can be carried out; but for patients subjected to malposition of device, failure of implantation intraoperatively or intolerance to device, revisions and salvages should be underwent with internal fixation of pedicle screws.

The mechanism by which hyperbaric oxygen treatment alleviates spinal cord injury: genome-wide transcriptome analysis.

Accumulating studies have demonstrated that hyperbaric oxygen (HBO) treatment alleviates spinal cord injury (SCI). However, the underlying mechanism by which HBO alleviates SCI remains to be elucidated. In this study, we performed genome-wide transcriptional profiling of the spinal cord between SCI mice and mice that received HBO treatment by high-throughput RNA sequencing at 1 week after SCI. We also compared genome-wide transcriptional profiles from SCI mice and sham-operated mice. We found 76 differentially co-expressed genes in sham-operated mice, SCI mice, and HBO-treated SCI mice. Using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis, we identified the biological characteristics of these differentially expressed genes from the perspectives of cell component, biological process, and molecular function. We also found enriched functional pathways including ferroptosis, calcium signaling pathway, serotonergic synapse, hypoxia-inducible factor-1 signaling pathway, cholinergic synapse, and neuroactive ligand-receptor interaction. We performed quantitative reverse transcription-polymerase chain reaction and validated that HBO treatment decreased the expression of Hspb1 (heat shock protein beta 1), Hmox1 (heme oxygenase 1), Ftl1 (ferritin light polypeptide 1), Tnc (tenascin C) and Igfbp3 (insulin-like growth factor binding protein 3) and increased the expression of Slc5a7 (solute carrier family 5 choline transporter member 7) after SCI. These results revealed the genome-wide transcriptional profile of the injured spinal cord after HBO treatment. Our findings contribute to a better understanding of the mechanism by which HBO treats SCI and may provide new targets for SCI intervention.

[The anatomic study of transferring thoracic nerve roots to lumbar nerve root inside the spinal canal of paraplegia].

OBJECTIVE: To study the fundamental anatomy of transferring T(9-12) nerve roots to L(2-4) nerve root for the quadriceps function recovery inside the spinal canal of paraplegia. METHODS: Thoracic and lumbar spinal canal and spinal dura mater of 5 adult cadavers (male 2 and female 3) were opened and explored. Investigated including: the position which T9-L4 nerve root generated from spinal cord; the relation between the position which T9-L4 nerve root generated from spinal cord and T12 vertebrae and L1 vertebrae; The length beginning part of T9-L4 nerve root inside the spinal canal. The diameter of T9-L4 nerve root. The distance between the T9-L4 nerve root separately. The distance between the position which T(9-12) nerve root separately generated from dura mater and the middle of L2 vertebrae. RESULTS: T9 nerve root generated from the middle part of T9 vertebrae; L4 nerve root generates from middle part of L2 vertebrae. The average length of T9-L4 nerve root inside the spinal canal separately was 16.12, 22.97, 30.43, 43.47, 56.02, 70.03, 88.70 and 113.65 mm. The average diameter of T9-L4 nerve root separately was 2.45, 2.04, 1.96, 2.18, 2.32, 2.56, 3.10 and 3.26 mm. The average distance between the beginning part of T9-L4 nerve root separately was 22.87, 25.08, 28.47, 27.38, 29.78, 31.93 and 31.00 mm. The average distance between the position which T(9-12) nerve root separately generated from dura mater and the middle of L2 vertebrae was 118.69, 95.82, 70.74, and 42.27 mm. CONCLUSIONS: T(9-12) nerve root can be used as donor nerve for repair L(2-4) nerve root. The level of L2 vertebrae can be anastomose site of the recipient nerve.

[Total lumbar disc replacement with SB Charité III prosthesis: Chinese experience with more than two years follow-up].

OBJECTIVE: To evaluate the clinical and radiographic results of total lumbar disc replacement with SB Charité III prosthesis. METHODS: From Dec 1999 to Dec 2006, total lumbar disc replacement with SB Charité III prosthesis was performed in 65 patients affected with degenerative lumbar disc disorders. Among these patients, 48 (52 prosthesis) were followed up for more than two years (from 2.0 to 7.5 years). There were 22 males and 26 females with an average age of 43 years old (from 36 to 58 years). The diagnosis was lumbar disc herniation with low back pain in 34 patients, discogenic low back pain in 9 patients and failed lumbar disc surgery in 5 patients. All patients underwent standard anterior procedure under general anesthesia. One level replacement was done in 44 patients (L3,4 in 3, L4,5 in 23 and L5-S1 in 18), and two level procedures in 4 patients (L3,4/L4,5 in 1 and L4,5/L5-S1 in 3). Clinical and radiographic results of these patients were evaluated at each follow-up time (1, 3, 6, 12, 24 months after operation and the latest). RESULTS: The average visual analogue scales score for pain was 9.3 before operation, changed to 4.3 one month after operation, further declined to 2.6 two years after operation and finally to 1.8 at the latest follow-up evaluation. Meanwhile, the average Oswestry Disability Index was 45.8 before operation, 28.6 one month after operation, 12.5 two years after operation and 8.2 at the latest followup evaluation. All operated levels but one maintained mobile and there was no significant loss of range of motion observed. Complications such as implant dislocation or significant subsidence of the prosthesis occurred in none case of this group. All patients but one (98%) were satisfied with the surgery at the latest follow-up evaluation. CONCLUSIONS: Total lumbar disc replacement is an effective method for the treatment of degenerative disc disorders. Its long-term outcome remains to be verified.

Evaluation of Coflex interspinous stabilization following decompression compared with decompression and posterior lumbar interbody fusion for the treatment of lumbar degenerative disease: A minimum 5-year follow-up study.

Few studies have compared the clinical and radiological outcomes between Coflex interspinous stabilization and posterior lumbar interbody fusion (PLIF) for degenerative lumbar disease. We compared the at least 5-year clinical and radiological outcomes of Coflex stabilization and PLIF for lumbar degenerative disease. Eighty-seven consecutive patients with lumbar degenerative disease were retrospectively reviewed. Forty-two patients underwent decompression and Coflex interspinous stabilization (Coflex group), 45 patients underwent decompression and PLIF (PLIF group). Clinical and radiological outcomes were evaluated. Coflex subjects experienced less blood loss, shorter hospital stays and shorter operative time than PLIF (all p<0.001). Both groups demonstrated significant improvement in Oswestry Disability Index and visual analogue scale back and leg pain at each follow-up time point. The Coflex group had significantly better clinical outcomes during early follow-up. At final follow-up, the superior and inferior adjacent segments motion had no significant change in the Coflex group, while the superior adjacent segment motion increased significantly in the PLIF group. At final follow-up, the operative level motion was significantly decreased in both groups, but was greater in the Coflex group. The reoperation rate for adjacent segment disease was higher in the PLIF group, but this did not achieve statistical significance (11.1% vs. 4.8%, p=0.277). Both groups provided sustainable improved clinical outcomes for lumbar degenerative disease through at least 5-year follow-up. The Coflex group had significantly better early efficacy than the PLIF group. Coflex interspinous implantation after decompression is safe and effective for lumbar degenerative disease.

Acute pulmonary embolism following adolescent idiopathic scoliosis correction surgery: case report and review of literature.

Pulmonary embolism is a significant complication of surgery. This report presents a case of suspected fatal postoperative acute pulmonary embolism following posterior correction surgery in a 16-year-old female with idiopathic scoliosis. The patient presented with a suspected pulmonary embolism 2 h postoperatively. She lost consciousness quickly, and cardiac respiratory arrest occurred. Cardiopulmonary resuscitation was started immediately. The patient was stabilized but underwent a further suspected pulmonary embolism the following day. Cardiopulmonary resuscitation was performed again, but she lost consciousness and respirator support was required. At 40 days after surgery, a computed tomography scan revealed an area of necrotic brain tissue near the lateral cerebral ventricle. The patient remained in a comatose state for 16 months, after which active management was withdrawn. This case reminds us to be alert to potentially fatal postoperative pulmonary embolism in young patients without any risk factors for thrombosis.

Device related complications of the Coflex interspinous process implant for the lumbar spine.

BACKGROUND: Coflex, a type of interspinous process implant, can provide intervertebral dynamic stability for surgical segments and effectively relieve lumbocrural pain. However, few studies have described therapeutic strategies and the avoidance of Coflex implant complications. METHODS: Coflex implant complications in this study included intraoperative or postoperative spinous process fracture, aggravated postoperative lumbocrural pain, dislodgment and malposition. The complications were analyzed, and therapeutic strategies were applied according to the specific complication. The Visual Analogue Scale and Oswestry Disability Index scores were evaluated by using the paired-samples test from SPSS 12.0. RESULTS: Conservative treatment was provided to seven patients who experienced aggravated lumbocrural pain even though their devices remained in the correct position, and pedicle screw treatment was used as an alternative in four cases. The Visual Analogue Scale and Oswestry Disability Index scores showed evident improvement in these patients. The Visual Analogue Scale and Oswestry Disability Index scores of two patients who underwent revision were also improved. CONCLUSIONS: Coflex implants should be avoided in patients with osteoporosis, a narrow interspinous space and intervertebral coronal spondylolysis, or sagittal instability. Furthermore the device choice, depth of implantation, and clamping intensity should be appropriate. Conservative treatment can be provided to patients with symptoms if the device remains in the correct position; however, revisions and salvages should be undertaken with internal fixation of pedicle screws for patients with device malposition, intraoperative implantation failure, or device intolerance.

Hyperbaric oxygen intervention on expression of hypoxia-inducible factor-1α and vascular endothelial growth factor in spinal cord injury models in rats.

BACKGROUND: Hyperbaric oxygen (HBO) intervention is a main therapeutic method and the curative effect has been certified for spinal cord injury (SCI), but the mechanisms of the neuroprotective effect of HBO on SCI remain elusive. This study aimed to observe the change in expression of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) after SCI at different time points and to investigate the neuroprotective mechanism of HBO on SCI in rats. METHODS: A total of 160 adult Sprague-Dawley rats, weighing between 250 and 300 g, were randomly assigned to four experimental groups (n = 40 per group). SCI group: SCI was created with a special NYU impactor of Allen's by a 25 gramcentimeter impacting energy on T10 of the spinal cord. SCI+HBO group: HBO therapy after SCI model was established. Sham operation (SH) group: only laminectomy of T10 and no impact on the spinal cord was done. SH+HBO group: HBO therapy after sham operation. The hindlimb functional recovery was evaluated using Basso, Beattie, and Bresnahan (BBB) score and the expressions of HIF-1α and VEGF were observed with fluorescent quantitation PCR and Western blotting method of six rats picked randomly from each group at different time points of 1, 3, 7, and 14 days after operation. RESULTS: Rats in the SCI group and SCI+HBO group were paralyzed completely after operation with BBB 0-1 score. Rats in the SH group and SH+HBO group could walk after sham operation with BBB 20-21 score. The BBB score of rats in the SCI+HBO group (4.67±1.97 and 10.83±2.23) was higher than that in the SCI group (1.83±0.75 and 6.67±2.16) at 7 and 14 days time points obviously (P < 0.05). The expressions of HIF-1a and VEGF in the SCI group and SCI+HBO group were higher than in the SH group and SH+HBO group at any time point obviously (P < 0.05), while the SCI+HBO group presented the least expression of HIF-1α mRNA and protein (3.82±0.41 and 0.59±0.06; 2.26±0.41 and 0.37±0.05; 1.58±0.26 and 0.29±0.05) than that in the SCI group (6.36±0.58 and 0.76±0.07; 3.55±0.47 and 0.51±0.07; 2.27±0.39 and 0.40±0.06) respectively at 3, 7, and 14 days time points (P < 0.05) with significant difference and more expression of VEGF mRNA and protein (5.83±0.77 and 0.72±0.06; 4.59±0.51 and 0.63±0.06) than that in the SCI group (3.06±0.30 and 0.48±0.07; 2.25±0.24 and 0.39±0.09) respectively at 7 and 14 days time points (P < 0.05) with significant difference. CONCLUSIONS: HBO could improve the hind limb functional recovery after SCI in rats. The elevation and duration of the expression of VEGF and the reduction of expression of HIF-1α by HBO intervention may be inversely related in the repair of damaged spinal cord and neuroprotective effect.