Factors associated with non-fusion after direct pars repair of lumbar spondylolysis with pedicle screw and lamina hook: a clinical and CT-assessed study.

BACKGROUND: Pedicle screw and lamina hook (PSLH) technique is an effective and popular method for direct pars repair of lumbar spondylolysis. There is a lack of studies to explore factors that may influence the healing of spondylolysis after direct pars repair surgery. The present study aimed to investigate the factors associated with non-fusion after direct pars repair of lumbar spondylolysis with PSLH technique. METHODS: A total of 55 subjects (average age 21.1 ± 6.3 years, a total of 120 pars defects) diagnosed with symptomatic spondylolysis and underwent pars repair surgery with PSLH were followed up and their clinical data were analyzed. Subjects were divided into a non-fusion group and fusion group according to whether the pars defect had bony fusion at last follow-up assessed by CT. Radiographic data, data related to spondylolysis and clinical outcomes were collected and compared between groups. RESULTS: The mean follow-up time of the 55 patients was 24.8 ± 12.0 (12-64) months. Among the 120 pars defects, 101 defects were successfully fused and 19 were not fused according to CT. The fusion rate was 84.2%. Multivariable logistic regression analysis showed the factors correlated with non-fusion after pars repair surgery: whether the spondylolysis segment was associated with spina bifida occulta (SBO) (P = 0.001), stage of the defect (P = 0.047), width of the defect (P = 0.002), and disc degeneration (P = 0.014). CONCLUSION: Direct pars repair by PSHL is a reliable treatment for lumbar spondylolysis with a fusion rate of 84.2%. Association with SBO of the spondylolysis segment, a terminal stage of the defect, a wider defect gap, and grade III disc degeneration may be factors associated with non-fusion after direct pars repair of lumbar spondylolysis with PLSH. Non-fusion patients after pars repair appear to have worse clinical results compared to fusion patients.

The effects of psychological distress after surgery in patients undergoing lumbar spinal fusion.

BACKGROUND: The aim of this study was to evaluate the psychological distress pre-operatively, at 3, 6, and 12 months in patients who underwent lumbar spine fusion surgery. METHODS: A total of 440 patients received instrumented lumbar spine fusion were enrolled. Psychological distress was evaluated using the Modified Somatic Perception Questionnaire (MSPQ) and the Modified Zung Depressive Index (ZDI). The results of lumbar fusion surgery were evaluated using the Oswestry Disability Index (ODI), the Japanese Orthopedic Association (JOA-29), and the visual analog scale (VAS). RESULTS: Psychological distress was reported among 23% of patients and 7, 5.5, and 4.0% of the patients preoperatively, at 3, 6, and 12 months after lumbar surgery, respectively. The mean MSPQ score decreased from 8.78 (before surgery) to 4.30, 3.52, and 3.43 at 3, 6 and 12 months in after surgery, respectively, in patients with psychological distress patients (p < 0.001). The mean ZDI score decreased from 17.78 to 12.48, 10.35, and 9.61 (p < 0.001). The mean ODI score decreased from 22.91 to 11.78, 10.13, and 9.96 (P < 0.001). The mean JOA score increased from 13.65 to 22.30, 23.43, and 23.61 (P < 0.001). The mean low back pain (LBP) VAS score decreased from 4.48 to 1.96, 1.52, and 1.51 (P < 0.001); moreover, the mean leg pain (LP) VAS score decreased from 5.30 to 1.30, 1.04, and 1.03 (P < 0.001). CONCLUSIONS: Patients with psychological distress may experience surgical intervention benefits equal to those of ordinary patients. Moreover, reduced pain and disability after surgical intervention may also alleviate psychological distress. Hence, we highly recommend that patients with psychological distress undergo surgical intervention as normal patients do, but appropriate screening measures and interventions are necessary.

Banner cloud sign: a novel method for the diagnosis of dural ossification in patients with thoracic ossification of the ligamentum flavum.

PURPOSE: Dural ossification (DO) is common in patients with ossification of the ligamentum flavum (OLF) and is the leading cause of dural tears. However, the methods used for DO diagnosis are limited. The purpose of this study was to propose a novel CT-based imaging sign, Banner cloud sign (BCs), and clarify its clinical characteristics and correlations with DO. METHODS: 57 OLF patients who underwent thoracic spine decompression surgery in our single-center between January- and October-2018 were recruited and divided into two groups based on the presence of DO. Patient demographics and radiographic data were analyzed. Hematoxylin-eosin staining and micro-CT were used to detect the micro-morphological changes of DO. The diagnostic value of BCs for DO was assessed by sensitivity and specificity. RESULTS: 12 patients with a total of 19 segments were diagnosed as DO. The incidence of DO was 21.1% (12/57) in OLF patients and 9.5% (19/200) in OLF segments. Patients with DO had a shorter disease duration and a higher incidence of cerebrospinal fluid leakage than those without DO. Hematoxylin-eosin staining and micro-CT showed that the dura mater was ossified and fused with ossified ligamentum flavum, and diffusion along the dura mater, like a banner cloud flying on the mountain. The sensitivity and specificity of BCs in DO diagnosis were 78.9 and 90.6%, respectively. CONCLUSION: BCs can vividly and intuitively describe the imaging features of DO and has high diagnostic accuracy. It could be a promising and valuable method for the diagnosis of DO.

A sheep model of chronic cervical compressive myelopathy via an implantable wireless compression device.

PURPOSE: This study aimed to establish an animal model in which we can precisely displace the spinal cord and therefore mimic the chronic spinal compression of cervical spondylotic myelopathy. METHODS: In vivo intervertebral compression devices (IVCDs) connected with subcutaneous control modules (SCCMs) were implanted into the C2-3 intervertebral disk spaces of sheep and connected by Bluetooth to an in vitro control system. Sixteen sheep were divided into four groups: (Group A) control; (Group B) 10-week progressive compression, then held; (Group C) 20-week progressive compression, then held; and (Group D) 20-week progressive compression, then decompression. Electrophysiological analysis (latency and amplitude of the N1-P1-N2 wave in somatosensory evoked potentials, SEP), behavioral changes (Tarlov score), imaging test (encroachment ratio (ER) of intraspinal invasion determined by X-ray and CT scan), and histological examinations (hematoxylin and eosin, Nissl, and TUNEL staining) were performed to assess the efficacy of our model. RESULTS: Tarlov scores gradually decreased as compression increased with time and partially recovered after decompression. The Pearson correlation coefficient between ER and time was r = 0.993 (p < 0.001) in Group B at 10 weeks and Groups C and D at 20 weeks. And ER was negatively correlated with the Tarlov score (r = -0.878, p < 0.001). As compression progressed, the SEP latency was significantly extended (p < 0.001), and the amplitude significantly decreased (p < 0.001), while they were both partially restored after decompression. The number of abnormal motor neurons and TUNEL-positive cells increased significantly (p < 0.001) with compression. CONCLUSION: Our implantable and wireless intervertebral compression model demonstrated outstanding controllability and reproducibility in simulating chronic cervical spinal cord compression in animals.

Scoliosis in dysplastic spondylolisthesis: a clinical survey of 50 young patients.

BACKGROUND: Dysplastic spondylolisthesis is a rare spinal deformity that occurs mainly in young patients. Although its sagittal parameters had been well stated, coronal abnormalities in these patients were poorly studied. The purposes of this study were: (1) to investigate the prevalence of scoliosis in dysplastic spondylolisthesis;(2) to assess scoliosis resolution or persistence after surgery; and (3) to propose a modified classification of scoliosis associated with dysplastic spondylolisthesis. METHODS: Fifty patients (average age 14.9 ± 5.6 years) diagnosed with dysplastic spondylolisthesis who underwent surgical treatment were followed up and their data were analyzed. Standing posteroanterior and lateral full spine radiographs were used to measure the coronal and sagittal parameters. Patients with scoliosis, which was defined as a coronal Cobb angle greater than 10°, were divided into three groups according to their curve characteristics: "independent" scoliosis (IS) group, spasm scoliosis (SS) group, and olisthetic scoliosis (OS) group. SS and OS were spondylolisthesis-induced scoliosis. The radiographic parameters and patient-reported outcomes were collected before and after surgery and compared between groups. RESULTS: The average slip percentage was 62.8% ± 23.1% and the average follow-up time was 51.5 ± 36.4 months (range 3-168 months). Twenty-eight of the 50 (56%) dysplastic spondylolisthesis patients showed scoliosis, of which 8 were IS (24.7° ± 15.2°), 11 were SS (13.9° ± 3.0°), and 9 were OS (12.9° ± 1.9°). By the last follow-up, no scoliosis resolution was observed in the IS group whereas all SS patients were relieved. Of the nine patients with OS, four (44.4%) had scoliosis resolution after surgery. CONCLUSION: Distinguishing different types of scoliosis in dysplastic spondylolisthesis patients may help surgeons to plan treatment and understand prognosis. For patients with significant scoliosis, whether "independent" or spondylolisthesis-induced, treatment of spondylolisthesis should be performed first and scoliosis should be observed for a period of time and treated according to the corresponding principles.

Imaging signs for preoperative diagnosis of dural ossification in patients with thoracic ossification of the ligamentum flavum: a blind, randomized diagnostic accuracy study.

Background: Dural ossification (DO) is the leading cause of surgery-related dural tear in patients with ossification of the ligamentum flavum (OLF). An accurate preoperative diagnosis of DO is conducive to the selection of appropriate surgical methods. Although several imaging signs, such as Banner cloud sign (BCs), tram-track sign (TTs), and comma sign (Cs) have been proposed for the preoperative diagnosis of DO, their diagnostic value has not been well studied. The aim of this study was to explore the diagnostic value of BCs, TTs, and Cs, and provide evidence-based data for their clinical application. Methods: This is a blind, randomized diagnostic study using retrospectively collected data from 102 consecutive patients who were diagnosed with OLF and underwent decompression surgery between January 2018 and June 2019. A total of 8 surgeons with different qualifications were recruited to read these imaging signs to identify the presence of DO. Surgical records were used as the reference standard. Sensitivity, specificity, and the area under the receiver operating characteristic (ROC) curve (AUC) were used to evaluate the diagnostic accuracy of each imaging sign and their different combinations. Results: Of the 102 patients, 21 were diagnosed with DO. BCs had a significantly higher diagnostic accuracy than TTs and Cs, with the AUC of 0.704, 0.607, and 0.593, respectively. The specificity of BCs, Cs, TTs, and their combination in diagnosing DO was 91.5%, 92.1%, 68.3%, and 62.2%, respectively. In the combined diagnostic test, the results showed that the combined diagnosis accuracy of BCs and Cs was the highest, and the AUC was 0.738. The combination of BCs, Cs, and TTs increased the sensitivity of diagnosing DO (77.5%), but did not improve the diagnostic accuracy, and the AUC was 0.699. Conclusions: BCs had higher diagnostic accuracy than TTs and Cs. BCs and Cs were highly specific for DO, whereas TTs could be confusing due to their non-specific presentations. The combination of BCs, TTs, and Cs improved the sensitivity of DO diagnosis, but not the specificity and accuracy.

Management of Tracheal Perforation following Anterior Cervical Spine Surgery: Report of Two Cases and Review of the Literature.

Background: Tracheal perforation is a complication very rare but challenging that follows anterior cervical spine surgery. This article describes the management of tracheal perforation due to instrument failure after anterior cervical spine surgery performed in two patients because of fracture dislocation of the subaxial cervical spine. Case Presentation. Two patients who suffered from a subaxial cervical fracture and dislocation were subjected to anterior cervical spine surgery for fracture reduction and cervical fusion. However, instrumentation failure occurred in both patients, resulting in implant displacement and penetration into the posterior tracheal wall. Revision surgery consisted of fracture reduction, multilevel posterior fixation, and removal of the displaced anterior cervical implants. Tracheal perforation was bypassed by placing a tracheostomy tube in a caudal position for the diversion of the airflow and tracheal hygiene. The thorough debridement and drainage performed in both patients allowed a complete healing of the anterior wound in both of them, with no sign of infection or subcutaneous emphysema, as confirmed by postoperative CT scan and flexible bronchoscopy. Both patients acquired a solid fusion of the cervical spine at last follow-up (16 months and 24 months). Conclusions: The perforation of the trachea after anterior cervical spine surgery due to the displacement of the implants could be managed using posterior cervical instrumentation and fusion, the removal of the anterior implant, debridement and drainage, and the use of a distal bypassing tracheostomy tube.

Cervical sagittal alignment in adolescent high dysplastic developmental spondylolisthesis: how does the cervical spine respond to the reduction of spondylolisthesis?

BACKGROUND: Although pelvic and related parameters have been well stated in lumbar developmental spondylolisthesis, cervical sagittal alignment in these patients is poorly studied, especially in high dysplastic developmental spondylolisthesis (HDDS). The purpose of this study is to investigate the sagittal alignment of the cervical spine in HDDS and how the cervical spine responds to reduction of spondylolisthesis. METHODS: Thirty-three adolescent patients with lumbar developmental spondylolisthesis who received preoperative and postoperative whole-spine x-rays were reviewed. They were divided into the HDDS group (n = 24, 13.0 ± 2.2 years old) and the low dysplastic developmental spondylolisthesis (LDDS) group (n = 9, 15.6 ± 1.9 years old). Spinal and pelvic sagittal parameters, including cervical lordosis (CL), were measured and compared between groups. In the HDDS group, the postoperative parameters were measured and compared with those before surgery. RESULTS: HDDS group had a higher proportion of cervical kyphosis (70.8% vs. 22.2%, P = 0.019), and there was a significant difference in CL between the two groups (- 8.5° ± 16.1° vs. 10.5° ± 11.8°, P = 0.003). CL was correlated with the Dubousset's lumbosacral angle (Dub-LSA), pelvic tilt (PT), and thoracic kyphosis (TK). In the HDDS group, CL in patients with a kyphotic cervical spine was significantly improved after reduction of spondylolisthesis (- 16.4° ± 5.9° vs. - 3.6° ± 9.9°, P < 0.001). In the HDDS group, 46% (6/13) of the patients with postoperative Dub-LSA < 90° still had sagittal imbalance (sagittal vertical axis, [SVA] > 5 cm), while no sagittal imbalance was observed in patients with postoperative Dub-LSA > 90° (46% [6/13] vs. 0% [0/11], P = 0.016). CONCLUSIONS: HDDS can lead to cervical kyphosis through a series of compensatory mechanisms. Reduction of spondylolisthesis and correction of lumbosacral kyphosis may correct the cervical kyphosis and normalize the overall spinal sagittal profile. Correction of Dub-LSA to above 90° might be used as an objective to better improve the sagittal alignment of the spine.

Comparison between two types of "Scheuermann disease-like people": thoracolumbar disc herniation patients and healthy volunteers with radiological signs of Scheuermann's disease.

BACKGROUND: Scheuermann's disease (SD) is a spinal disorder and includes both a classic form and an atypical form. Interestingly, its existence among the general population as well as the disc disease patients is common. One of our previous studies showed that about 18% of the hospital staff members meet the SD criteria. On the other hand, another study has demonstrated that 95.2% of the symptomatic thoracolumbar disc herniation (STLDH) patients meet the SD criteria, which suggests that STLDH is very likely a special form of SD. The purpose of this study was to discriminate the factors contributing to the development of STLDH by comparing STLDH patients with the healthy SD-like hospital staff members. METHODS: This is a retrospective study including 33 STLDH patients who met the SD criteria and 30 SD-like hospital staff members. The STLDH group was chosen from a group of patients who underwent surgery after a diagnosis of STLDH (T10/11-L1/2) at our hospital between June 2007 and June 2010. SD-like hospital staff members were chosen from a database created in 2007, which contained a lumbar MR and low back pain (LBP) questionnaire of 188 hospital staff members. The demographic and radiologic characteristics were compared between groups. RESULTS: There was no statistical difference in sex, age, and height between the two groups. The STLDH patients had higher body weight, boby mass index, and thoracolumbar kyphotic angle than SD-like hospital staff members. In addition, STLDH patients had more levels of Schmorl's nodes (3.5±1.7 vs. 2.0±1.9, t = 3.364, P = 0.001) and irregular endplateson (4.0±1.9 vs. 2.7±1.9, t = 2.667, P = 0.010) compared to the SD-like hospital staff members. CONCLUSIONS: Higher body weight, higher body mass index, larger thoracolumbar kyphosis, and more Schmorl's nodes and irregular endplates on MR may be associated with the development of STLDH in "SD-like people."

Radiological signs of Scheuermann disease and low back pain: retrospective categorization of 188 hospital staff members with 6-year follow-up.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To investigate the relationship between radiological signs of Scheuermann disease (SD) and low back pain (LBP) in a local population using lumbar magnetic resonance (MR) images. SUMMARY OF BACKGROUND DATA: SD is a spinal disorder, and both its classic and atypical (lumbar) forms are associated with LBP. However, radiological signs of SD are present in 18% to 40% of the general population, in whom the clinical significance of "SD-like" spine remains largely unknown. METHODS: This retrospective cohort study included 188 staff members from a single hospital. Participants' lumbar MR images and self-administered questionnaires concerning demographic information, LBP status, consequences, and functional limitations were collected. Participants were classified into 2 groups according to whether lumbar MR images met SD diagnostic criteria, and LBP status, consequences, and functional limitation were compared. Follow-up interviews were conducted after 6 years to compare LBP progression. RESULTS: Thirty-four participants (18.1%) had SD-like spine. Rates of lifetime, previous 1-year, and point LBP did not significantly differ between groups. However, among participants who had ever had LBP, SD-like spine was associated with higher rates of work absence (42.1% vs. 9.5%, χ = 9.620, P = 0.002) and seeking medical care (68.4% vs. 39.2%, χ = 5.216, P = 0.022) due to LBP, as well as significantly greater intensity of the most severe LBP episode in the past 2 years (6.4 ± 2.5 vs. 4.1 ± 2.5, t = 3.564, P = 0.001). Among the 159 participants who completed the 6-year follow-up, a significantly higher proportion of people with SD-like spine reported aggravated LBP during the follow-up. CONCLUSION: Our results suggest that in the general population, lumbar MR images of many people meet SD diagnostic criteria, and having SD-like spine seemed to be associated with the severity and progressive nature of LBP. Our findings should inspire further research in this field. LEVEL OF EVIDENCE: 3.