The Comparison between Spinal Facet Joint Toothed Plate and Traditional Pedicle Screw-rod on Reduction of Thoracolumbar Fracture.

OBJECTIVE: Thoracolumbar fractures are one of the most common fractures in clinical practice. Surgical intervention is recommended to restore spinal alignment or decompress the nerves when there are unstable fractures or neurological injuries. However, after excessive forward thrust force restoration, facet joint dislocation often occurs between the upper vertebra and the fractured vertebra, which usually leads to unsatisfactory reduction outcomes. Herein, we propose a novel spinal facet joint toothed plate to assist in fracture reduction. The purpose of this study is to evaluate the effectiveness of the new spinal facet joint toothed plate in preventing facet joint dislocation, and its advantages compared to traditional pedicle screw-rod decompression. METHODS: A total of 26 patients in the toothed plate group and 93 patients in the traditional group who experienced thoracolumbar fracture with reduction were retrospectively included. Relevant patients' information and clinical parameters were collected. Furthermore, visual analogue scores (VAS) scores and Oswestry disability index (ODI) scores were also collected. Moreover, imaging parameters were calculated based on radiographs. Correlated data were analyzed by χ2 test and t test. RESULTS: All patients in this study had no postoperative complications. Postoperative VAS scores and ODI scores (p < 0.001) were statistically significant (p < 0.001) in both groups compared with preoperative scores and further decreased (p < 0.001) at final follow-up. In addition, the postoperative vertebral margin ratio (VMR) (p < 0.001) and vertebral angle of the injured vertebrae (p < 0.001) were significantly improved compared with the preoperative period. There were no significant differences in postoperative VAS scores and ODI scores between the two groups. However, toothed plate reduction significantly improved the VMR (p < 0.05) and vertebral angle (p < 0.05) compared with conventional reduction. Ultimately, the total screw accuracy was 98.72% (sum of levels 0 and I), with 100% screw accuracy in the segment related to the tooth plate in the tooth plate group. The dislocation rate was higher in the conventional group (6.45%) than in the new serrated plate repositioning group (0.00%). CONCLUSION: The facet toothed plate assisted reduction method prevents facet joint dislocation and improves fracture reduction compared to traditional reduction technique, hence it could be considered as a novel surgical strategy for thoracolumbar fracture reduction.

The surgical treatment of subaxial acute cervical spine facet dislocations in adults: a systematic review and meta-analysis.

Adult cervical spine traumatic facet joint dislocations occur when excessive traumatic forces displace the vertebrae's facets, leading to loss of joint congruence. Reduction requires either cranial traction or open surgical procedures. This study aims to appraise the effects of different surgical techniques in the treatment of subaxial cervical spine acute traumatic facet blocks in adults. This study was based on a systematic literature review and meta-analysis, registered in Prospero (CRD42021279249). The PICO question was composed of adults with acute cervical spine traumatic facet dislocations submitted to anterior or posterior surgical approaches, associated or not with cranial traction for reduction. Each surgical technique was compared to the other. The primary clinical outcomes included neurological improvement or worsening and surgical success/failure rates. The anterior approach without cranial traction was efficient in reducing facet displacements. Skull traction was an efficient and immediate method to achieve spine dislocation reductions. Differences were not present among techniques regarding neurological improvement. There were no surgical failures in patients operated on via the posterior approach. The need to decompress and stabilize the cervical spine can be achieved by anterior or posterior surgical approaches, and there is no clear answer as to which initial approach is superior to the other.

Classification of unilateral cervical locked facet with or without lateral mass-facet fractures and a retrospective observational study of 55 cases.

This study describes a morphology-based unilateral cervical facet interlocking classification in an attempt to clarify the injury mechanism, instability, neurological deficits, radiological features, and determine optimum management strategies for these injuries. A total of 55 patients with unilateral cervical locked facet (UCLF) involving C3 to C7 were identified between January 1, 2012 and December 1, 2019. The injuries were classified into three types, and they were further divided into six subtypes using three-dimensional computed tomography. The injury mechanism, clinical features, neurological deficits, and imaging characteristics were analyzed, and the appropriate treatment strategies for UCLF were discussed. UCLFs were divided into the following six subtypes: UCLF without lateral mass-facet fracture (type I) in nine cases, with superior articular process fracture (type II A) in 22, with inferior articular process fracture (type II B) in seven, both superior and inferior articular process fractures (type II C) in four, with lateral mass splitting fracture (type III A) in three, and with lateral mass comminution fractures (type III B) in ten. A total of 22 (40.0%) of the 55 patients presented with radiculopathy, and 23 patients (41.8%) had spinal cord injuries. The subtype analyses showed high rates of radiculopathy in types II A (68.2%) and II C (75.0%), as well as significant spinal cord injury in types I (77.8%) and III (61.5%). Destruction of the facet capsule was observed in all patients, but the injury of disc, ligamentous complex, and vertebra had a significant difference among the types or subtypes. The instability parameters of the axial rotation angle, segmental kyphosis, and sagittal displacement showed significant differences in various types of UCLF. Closed reduction by preoperative and intraoperative general anesthesia traction was achieved in 27 patients (49.1%), and successful rate of closed reduction in type I (22.2%) was significantly lower than that in type II (51.5%) and type III (61.5%). A total of 35 of 55 patients underwent a single anterior fixation and fusion, 10 patients were treated with posterior pedicle and (or) lateral mass fixation, and combined surgery was performed in ten patients. Ten patients (18.2%) with a poor outcome were observed after first surgery. Among them, 3 patients treated with a single anterior surgery had persistent or aggravated radiculopathy and posterior approach surgery with ipsilateral facet resection, foramen enlargement, and pedicle and (or) lateral mass screw fixation was performed immediately, 5 patients treated with a short-segment posterior surgery showed mild late kyphosis deformity, and 2 patients with vertebral malalignment were encountered after anterior single-level fusion during the follow-up. This retrospective study indicated that UCLF is a rotationally unstable cervical spine injury. The classification proposed in this study will contribute to understanding the injury mechanism, radiological characteristics, and neurological deficits in various types of UCLF, which will help the surgeons to evaluate the preoperative closed reduction and guide the selection of surgical approach and fusion segment.

Posterior Ligament-Bone Injury Classification and Severity Score: A Novel Approach to Predict the Failure of Anterior-only Surgery for Subaxial Cervical Facet Dislocations.

STUDY DESIGN: Clinical case series. OBJECTIVE: The aim of this study was to propose a novel posterior ligament-bone injury classification and severity (PLICS) score system that can be used to reflect the severity of subaxial cervical fracture dislocations (SCFDs) and predict the failure of anterior-only surgery; and to measure the intraobserver and interobserver reliability of this system. SUMMARY OF BACKGROUND DATA: The approach selection for SCFDs is controversial. Although the anterior approach is familiar for most surgeons, postoperative hardware failure and/or delayed cervical deformity is a nonnegligible complication. METHODS: Ten patients were randomly selected for intraobserver reliability evaluation on two separate occasions, one month apart. Another 30 patients were randomly selected, and the interobserver reliability was measured by comparing results of each case between each reviewer and averaging. To analyze the difference in the PLICS score, 354 patients fulfilled the follow-up were divided into stable and unstable groups according to whether radiologically stable was observed during follow-up. RESULTS: For the intraobserver reliability, the mean intraclass correlation coefficient for the 10 reviewers was 0.931. For the interobserver reliability, the mean interobserver correlation coefficient for the three elements was 0.863. Among 16 patients with PLICS score ≥7, two patients in the stable group manifested with severe injury of the posterior ligamentous complex (PLC); extremely unstable lateral mass fractures with or without severe injury of PLC were detected in the 14 patients of the unstable group. CONCLUSION: The proposed PLICS score system showed excellent intraobserver and interobserver reliability. When a PLICS score is >7 or 7 accompanied by extremely unstable lateral mass fractures, the risk of postoperative failure after an anterior-only reconstruction is high and supplemental posterior strengthening can be considered.Level of Evidence: 4.

Emergency surgical management of cervical spine fracture-dislocation with acute paraplegia in COVID-19 (Coronavirus disease 2019)-suspected patient: first experience from a German spine centre.

PURPOSE: We present an organized hospital plan for the management of Coronavirus disease (COVID-19) patients requiring emergency surgical interventions. To introduce a multidisciplinary approach for the management of COVID-19-infected patients and to report the first operated patient in the Corona unit. METHODS: A detailed presentation of the hospital plan for a separate Corona unit with its intensive care unit and operating rooms. Description of the management of the first spine surgery case treated in this unit. RESULTS: The Corona unit showed a practical approach for the management of an emergency cervical spine fracture-dislocation with acute paralysis. The patient is 92-year-old female. The mechanism of injury was a simple fall during the stay in the internal medicine department where the patient was treated in the referring hospital. The patient had no other injuries and was awake and oriented. The patient did not have the clinical symptom of COVID-19, and the test result of COVID-19 done in the referring hospital was not available on admission in our emergency room. Education of the medical staff and organization of the operating theatre facilitated the management of the patient without an increased risk of spreading the infection. CONCLUSIONS: The current COVID-19 pandemic requires an extra-ordinary organization of the medical and surgical care of the patients. It is possible to manage an infected or a potentially infected patient surgically, but a multidisciplinary plan is necessary to protect other patients and the medical staff.

Management of Neglected Post-traumatic Bilateral Facet Dislocation of Sub-axial Cervical Spine: A Case Series.

Neglected bilateral facet dislocation of the lower cervical spine is a rare condition and found mostly in developing countries like Nepal. Delayed presentation makes treatment more challenging concerning decompression, reduction, neurological recovery, and overall outcome. We managed three cases of bilateral facet dislocations of the fifth-sixth-seventh cervical vertebra level presented after three months of injury. All of those were treated surgically by combined anterior-posterioranterior approaches with the same principle. One patient had a complete neurological recovery, the second one recovered partially with few long-term complications and the third one did not improve at all.

An Experimental Study on the Safety and Mechanism of Reduction of Subaxial Cervical Facet Dislocation Using Z-Shape Elevating-Pulling Reduction Technique.

OBJECTIVE: We sought to clarify the safety and unlocking mechanism of the Z-shape elevating-pulling closed reduction (ZR) technique and to analyze the differences in facet contact force and intraspinal pressure during subaxial facet dislocation reduction using the ZR technique and traditional skull traction closed reduction (SR). METHODS: In 15 human cadaveric skull-neck-thorax specimens, reproducible unilateral and bilateral facet dislocations (UFDs/BFDs) were created at the C5-C6 level and then reduced by applying the ZR and SR techniques, respectively. Tekscan FlexiForce A-201 pressure sensors were used to measure the anterior and posterior intraspinal pressure and injured facet contact force under physiological conditions and before and after reduction. The maximum pressures during the reduction process were recorded. RESULTS: After creation of the facet dislocation, the anterior and posterior intraspinal pressure and facet contact force were significantly increased relative to normal (P < 0.001). The UFDs and BFDs of all specimens were successfully reduced by both ZR and SR, and the intraspinal pressure and facet contact force were significantly reduced compared with before reduction (P < 0.001). Compared with SR, the maximum posterior intraspinal pressure during BFD reduction (P = 0.027) and the maximum facet contact force during UFD reduction (P < 0.001) were lower when ZR was used for closed reduction. CONCLUSIONS: Our findings suggest that ZR and SR can both be used to reduce subaxial facet dislocation and decompress the spinal cord. However, the ZR technique appears to safer and more effective than the SR technique for closed reduction of subaxial facet dislocations.

Acute traumatic unilateral cervical C4-C5 facet dislocation in pediatric toddlers.

BACKGROUND: The present study is to highlight the challenges in managing cervical spine injuries in toddlers (less than 4 years of age) without neurological deficit. Cases of unilateral cervical C4-C5 facet dislocation in toddlers are very rare. CASE PRESENTATION: A 3-year-old girl suffered cervical spine injury after a motor vehicle collision with unilateral C4-C5 facet dislocation without neurological deficit. Magnetic resonance imaging (MRI) showed no spinal cord injury, Frankel grade E. Initial management was cervical spine protection. Definite treatment and complication were discussed with the patient's parents before closed reduction maneuver with minerva cast was applied under sedation. The patient showed no complication after closed reduction and the cervical spine had aligned well in radiographs. The minerva cast was removed at 8 weeks, at which point neck muscle stretching rehabilitation program started. At one-year follow up, the child was asymptomatic, had full active cervical motion and good function. In radiographs, the cervical spine had normal alignment and was healed. CONCLUSIONS: Unilateral cervical facet dislocation in toddlers is very rare. Closed reduction maneuver and the minerva cast applied were optional in this case. The parents were highly satisfied with the effective treatment and outcome.

Shear stiffness in the lower cervical spine: Effect of sequential posterior element injury.

The aim of this study was to determine the effect of the posterior ligaments and facet joints on the shear stiffness of lower cervical functional spinal units in anterior, posterior, and lateral shear. Five functional spinal units were loaded in anterior, posterior, and right lateral shear up to 100 N using a custom-designed apparatus in a materials testing machine. Specimens were tested in three conditions: intact, with the posterior ligaments severed, and with the facet joints removed. There was a significant decrease in anterior stiffness in the 20-100 N load range from 186 (range: 98-327) N/mm in the intact condition to 105 (range: 78-142) N/mm in the disc-only condition (p = 0.03). Posterior stiffness between these condition decreased significantly from 134 (range: 92-182) N/mm to 119 (range: 83-181) N/mm (p = 0.03). There was no significant effect of posterior ligament removal on shear stiffness. No significant differences were found in the lateral direction or in the 0-20 N range for any direction. Under a 100-N shear load, the facet joints played a significant role in the stiffness of the cervical spine in the anterior-posterior direction, but not in the lateral direction.

Rate and Risk Factors of Superior Facet Joint Violation during Cortical Bone Trajectory Screw Placement: A Comparison of Robot-Assisted Approach with a Conventional Technique.

OBJECTIVE: To compare the incidence and risk factors of superior facet joint violation (FJV) during cortical bone trajectory screw placement in robot-assisted approach versus conventional technique. METHODS: A retrospective study, including 69 patients having cortical bone trajectory (CBT) screw instrumentation for symptomatic degenerated diseases or trauma, was conducted between June 2015 to January 2019. All patients underwent CBT surgery performed by the same team of experienced surgeons. Patients were randomly divided into two groups: a conventional group (CG, 46 cases) and a robot group (RG, 23 cases). The surgical robotic system was used for screw instrumentation in the robot group and the traditional screw instrumentation with fluoroscopic guidance was used in the conventional group. Cortical screws followed a medio-to-lateral path in the transverse plane and a caudal-to-cephalad path in the sagittal plane. Preoperative and postoperative computed tomography (CT) scans were obtained to determine the degree and incidence of FJV. The violation status of facet joint was evaluated according to the modified classification: grade 0, no violation; grade 1, screw shaft, screw head or rod within 1 mm of or abutting the facet joint, but did not enter the articular facet joint; grade 2, screw shaft, screw head or rod clearly in the facet joint. The following factors that may contribute to the occurrence of FJV were analyzed: age, sex, body mass index (BMI), proximal fusion level, fusion length, the side of screw, preoperative vertebral slip, superior facet angle, and degenerative scoliosis. The chi-squared test and Student's t-test were used for analysis of the variables for significance (P < 0.05). RESULTS: FJV occurred in 41.3% of patients in CG and 17.3% of patients in RG. A chi-squared analysis revealed a significantly lower rate of FJV for RG compared with CG (P = 0.04). In the CG, 17 of the 109 cephalad screws were grade 1 (15.6%), and five were grade 2 (4.6%). In the RG, three of the 46 cephalad screws were grade 1 (6.5%), and three were grade 2 (6.5%). There was a statistically significant difference in the incidence of FJV between the left and right screw with fluoroscopy-assisted CBT screw instrumentation (P < 0.05). A significant correlation between scoliosis with the FJV was found in CG (P < 0.05) and in RG (P < 0.05). With regard to superior facet angle, a measurement ≥45° was a significant risk factor of FJV in CG (P < 0.05) and in RG (P < 0.05). CONCLUSIONS: A robot-assisted approach could reduce the incidence of FJV compared with the conventional approach in CBT technique.

A Novel Anterior-Only Surgical Approach for Reduction and Fixation of Cervical Facet Dislocation.

BACKGROUND: The anterior-only surgical procedure, including discectomy, open reduction, fusion, and fixation, is a recommended approach in the treatment of cervical facet dislocations. This approach has a reduction failure rate of up to 40%. When it fails, a posterior approach is usually required. OBJECTIVE: To report a novel anterior-only surgical approach for reduction and fixation in patients with cervical facet dislocation, even for severe vertebral fracture, articular process fracture, and delayed surgical management. METHODS: Sixty-three consecutive patients with unilateral/bilateral facet dislocation of the subaxial cervical spine were treated with this anterior-only procedure. After discectomy, kyphotic paramedian distraction reduction with Caspar pins plus vertebral screw plate fixation was performed. If the reduction failed, anterior facetectomy reduction plus anterior cervical pedicle screw plate fixation was introduced. RESULTS: Among the 63 patients treated, 52 patients achieved successful reduction with the technique of kyphotic paramedian distraction with Caspar pins; the remaining 11 patients with failure of the former technique experienced successful reduction with the anterior facetectomy technique. No supplemental posterior approach surgery was performed. The American Spinal Injury Association grade was improved by at least 1 grade in 23 patients after this procedure, and no neurologic deterioration occurred in any of the patients. After at least 12 months of follow-up, all patients achieved satisfactory fusion, and there was no implant failure. CONCLUSIONS: An anterior-only surgical procedure including kyphotic paramedian distraction with Caspar pins, anterior facetectomy, and anterior pedicle screw plate fixation is safe and effective for subaxial cervical facet dislocations.

Maintenance of Integrity of Upper Facet Joints during Simulated Percutaneous Pedicle Screw Insertion Using 2D versus 3D Planning.

BACKGROUND: No studies have directly and quantitatively compared two-dimensional (2D) and three-dimensional (3D) planning as applied during conventional percutaneous or navigated percutaneous pedicle screw placement. STUDY AIMS: This lumbar pedicle-based stabilization simulation study aimed to investigate the risk of upper facet joint violation (FJV) during posterior percutaneous pedicle screw placement with conventional 2D planning of screw implantation (as a model for fluoroscopically guided screws) compared with 3D planning (as used with navigation techniques). METHODS: The placement of monosegmental lumbar pedicle screws using the data sets of 250 consecutive patients was simulated. Conventional surgery (using 2D fluoroscopic images anteroposterior and lateral view) was compared with screw placement using the 3D reconstruction of the planning mode of the same software. RESULTS: The 2D planning resulted in 140 upper FJVs (28% of cases), whereas 3D planning resulted in only 24 upper FJVs (4.8% of cases) (p < 0.05). Among those spinal segments with severe facet joint arthropathy, Pathria grades 3 and 4, FJV was significantly higher (p < 0.05) in the 2D-planned screws (64.7%) than in the 3D-planned screws (11.2%). A more lateral (mean distance: 3.5 mm) and inferior (mean distance: 2.5 mm) offset of the pedicle entry point and a larger medial angulation of the trajectory (mean angle: 9 degrees) were observed for the 3D-planned screws at all levels. CONCLUSION: This study demonstrates that the use of 2D planning is associated with a higher risk of upper FJV than when a 3D imaging data set is used. Using a more lateral and inferior entry point for fluoroscopically guided pedicle screws could reduce the rate of FJV in percutaneous pedicle screw placement.

There has to be an easier way: facet fracture characteristics that reliably differentiate AOSpine F1 and F2 injuries.

PURPOSE: To identify morphologic features of isolated cervical spine facet fractures that can reliably differentiate AOSpine F1 and F2 injuries. MATERIALS AND METHODS: Retrospective review of cervical spine CTs on all patients who sustained isolated cervical fractures of the facets presenting to our level 1 trauma center from August 2012 through December 2015. CTs were reviewed for facet fracture characteristics and AOSpine facet fracture classification. Association between facet fracture characteristics and AOSpine classification was assessed through multivariable logistic regression models. RESULTS: Fifty-six patients with cervical spine fractures isolated to the facets were included in the study. The mean age was 36 (range 9-90) years with 55.4% (n = 31) males. A significant correlation was found between subtype F1 and subtype F2 in laterality (left- or right-sided) (p = 0.004), interfacetal fracture involvement (p < 0.0001), transverse process involvement (p < 0.001), displacement of fracture fragment (p < 0.001), comminution of fracture (p < 0.0001), and vertebral arch disruption (p = 0.001). After multivariable analysis, left side laterality (p = 0.03), transverse process involvement (p = 0.01), and fracture comminution (p = 0.003) were associated with F2 fractures. CONCLUSION: Facet fractures with transverse process involvement or comminution have a higher probability of being an F2 fracture. These characteristics may be helpful when categorizing facet fractures using the AOSpine classification.

Anterior Reduction and Fusion of Cervical Facet Dislocations.

BACKGROUND: Cervical facet dislocations are among the most common traumatic spinal injuries. Posterior, anterior, and combined surgical approaches have been described and are widely debated. OBJECTIVE: To demonstrate efficacy in anterior-only surgical management for subaxial cervical facet dislocations. METHODS: A consistent surgical algorithm for cervical facet dislocation was applied over a 19-yr period and analyzed retrospectively in adults with acute unilateral or bilateral facet dislocation of the subaxial cervical spine. The primary endpoint was maintenance of early cervical alignment. The need for additional posterior instrumented fusion was determined. RESULTS: A database search identified 96 patients (mean age = 37.9, range = 14-74 yr, 68 (70%) male. The most common affected levels were C4-C5 (30), C5-C6 (29), and C6-C7 (30). Bilateral dislocation occurred in 51 patients (53%). Seventy-eight (81%) patients had neurological deficits, 31 (32%) being complete (Abbreviated Injury Score A) spinal cord injuries. Preoperative closed reduction was attempted in 60 (63%) patients, with 33 (55%) achieving satisfactory alignment. After anterior cervical discectomy, reduction, allograft placement, and instrumentation, a total of 92 (96%) patients had achieved satisfactory realignment. Median time to surgery was 13.27 h. Eight (8%) patients required posterior fixation due to intraoperative determination of incomplete realignment (4; 4%) and development of early progressive deformity (4; 4%). Mean follow-up was 4.5 mo (range 0.5-24 mo) with 33 (34%) patients lost to follow-up. CONCLUSION: Anterior approaches are viable for reduction and stabilization of cervical facet dislocations. Further prospective studies are required to evaluate clinical and long-term success.

Multicentre comparative study of Z-shape elevating-pulling reduction and skull traction reduction for treatment of lower cervical locked facets.

PURPOSE: The aim of this study was to assess the clinical efficacy and safety of Z-shape elevating-pulling reduction as compared to that of conventional skull traction in the treatment of lower cervical locked facet. METHODS: Patients with cervical locked facet (n = 63) were retrospectively enrolled from four medical centers and divided into two groups according to the pre-operative reduction method used: Z-shape elevating-pulling reduction (Z-shape elevating group; n = 20) or traditional skull traction reduction (skull traction group; n = 43). RESULTS: The success rates, efficacy of reduction, and safety were compared between the two groups. The success rates were significantly better in the Z-shape elevating group than in the skull traction group: 87.5% (7/8) vs. 35.3% (6/17) for unilateral locked facet reduction (P = 0.03) and 100% (12/12) vs. 69.2% (18/26) for bilateral locked facet reduction (P = 0.04). There was no obvious change in American Spinal Injury Association (ASIA) grade after the reduction in either group. Combined surgery was necessary in 5% in the Z-shape elevating group vs. 27.9% in the skull traction group. Imaging showed that the segment angle and horizontal displacement were significantly improved after surgery in both groups, with no significant difference between the groups. Follow-up with radiography showed good recovery of the cervical spine sequence; all internal fixation sites were stable, with no loosening, prolapse, or breakage of internal fixators. CONCLUSIONS: Halo vest-assisted Z-shape elevating-pulling reduction appears to be a simple, safe, and effective technique for pre-operative reduction of lower cervical locked facets.

Delayed bilateral facet dislocation at L4-5: A case report.

RATIONALE: Traumatic bilateral facet dislocation in the lumbar (L) spine has rarely been reported. All reported cases were presented with acute facet dislocation. However, we present the first case of delayed bilateral facet dislocation at L4-5. PATIENT CONCERNS: A 34-year-old woman presented with back pain after a head-on collision. The patient was treated conservatively for 3 months with rigid orthosis and activity restriction. Even after this conservative treatment, she continued to suffer from persistent back pain that radiated down her left leg and a progressively kyphotic posture. DIAGNOSES: Initial imaging studies revealed a fracture of the left L5 superior articular process with a posterior ligament complex (PLC) injury. Subsequent radiographs showed the locked facet dislocation with kyphotic changes. INTERVENTIONS: The patient underwent surgical reduction and fusion, and the operative findings revealed the L4-5 bilateral facet dislocation and rupture of the PLC at the index level. OUTCOMES: After surgical reduction and fusion at L4-5 by posterior interbody fusion, we achieved a satisfactory clinical outcome. LESSONS: Injury of the PLC in the lower lumbar region deserves careful attention for the development of sequelae. The anatomic transition from lordosis to kyphosis, in the lumbosacral region may be related to this type of injury.

CT for thoracic and lumbar spine fractures: Can CT findings accurately predict posterior ligament complex injury?

PURPOSE: This study aims to determine whether secondary CT findings can predict posterior ligament complex (PLC) injury in patients with acute thoracic (T) or lumbar (L) spine fractures. METHODS: This is a retrospective study of 105 patients with acute thoracic and lumbar spine fractures on CT, with MRI as the reference standard for PLC injury. Three readers graded CT for facet joint alignment (FJA), widening (FJW), pedicle or lamina fracture (PLF), spinous fracture (SPF), interspinous widening (ISW), vertebral translation (VBT), and posterior endplate fracture (PEF). Univariate and multivariate logistic regression analyses were performed separately for each reader to test for associations between CT and PLC injury, and diagnostic performance of CT was calculated. RESULTS: Fifty-three of 105 patients had PLC injury by MRI. Statistically significant predictors of PLC injury were VBT, PLF, ISW, and SPF. Using these four CT findings, odds of PLC injury ranged from 3.8 to 5.6 for one positive finding, but increased to 13.6-25.1 for two or more. At least one positive CT finding was found to yield average sensitivity of 82% and specificity 59%, while two or more yielded sensitivity 46% and specificity 88%. CONCLUSION: While no individual CT finding is sufficiently accurate to diagnose or exclude PLC injury, greater the number of positive CT findings (VBT, PLF, ISW, and SPF), the higher the odds of PLC injury. The presence of a single abnormal CT finding may warrant confirmatory MRI for PLC injury, while two or more CT findings may have adequate specificity to avoid need for MRI prior to surgical intervention. These slides can be retrieved under Electronic Supplementary Material.

Incidence and Risk Factors for Facet Joint Violation in Open Versus Minimally Invasive Procedures During Pedicle Screw Placement in Patients with Trauma.

OBJECTIVE: A possible risk factor for premature facet joint degeneration or adjacent segment degeneration after surgical treatment of spine fractures is facet joint violation (FV) during insertion of pedicle screws. The aim of this study was to determine risk factors for FV in the thoracic and lumbar spine after minimally invasive screw insertion or open instrumentation (OI). METHODS: A retrospective analysis of all patients with spine fractures requiring posterior stabilization was performed. After patients were allocated to the thoracic/lumbar group, FV was defined as an involvement caused by the positioning of a pedicle screw and its severity as determined by computed tomography was assessed by using a customized scoring system. Gender, age, and body mass index as well as segmental facet joint angle and the instrumentation system used (side-loading [SL] vs. top-loading) were considered as individual factors. RESULTS: In total, 1099 pedicle screws were evaluated and an FV was identified in 433 instrumentations (39.0%). OI was used in 61.1% (n = 671) and an SL system was inserted in 45.0% (n = 494). In both, the thoracic (odds ratio [OR], 1.663; 95% confidence interval [CI], 1.119-2.472; P = 0.012) and the lumbar spine (OR, 0.494; 95% CI, 0.317-0.771; P = 0.002), OI was associated with a lower risk of FV. The violation rate was significantly higher when using a SL system (thoracic spine: OR, 1.822; 95% CI, 1.163-2.854; P = 0.009; lumbar spine: OR, 0.311; 95% CI, 0.203-0.477; P ≤ 0.001). CONCLUSIONS: FV is a common complication after thoracic and lumbar spine surgery. Although both, the SL instrumentation and a minimally invasive procedure increases its occurrence, the patient characteristics do not affect the rate of FV.

New reduction technique for the treatment of unilateral locked facet joints of the lower cervical spine : A retrospective analysis of 12 cases.

BACKGROUND: Closed reduction of bilateral locked facet joints of the lower cervical spine is possible, but reduction of unilateral locked facet joints of the lower cervical spine (ULFJLCS) is challenging. We explored a new, simple, safe, and effective closed reduction method for the treatment of ULFJLCS. METHODS: A retrospective analysis was done on 12 consecutive cases with traumatic ULFJLCS that underwent closed reduction by Z­shape elevating-pulling reduction through a halo-vest. After reduction, only anterior cervical decompression and internal fixation were performed. The success of reduction and nerve function was assessed, and follow-up data analyzed. RESULTS: All patients using our new reduction technique underwent successful closed reduction; the shortest time of reduction was 40 min and the longest 110 (mean, 65) min. No aggravation of neurological damage was observed, nor were other complications. All patients were followed-up from 28 to 72 (mean, 44) months after surgery. The improvement in Frankel's score (on average) was two levels in most patients. CONCLUSION: These data demonstrate that our new reduction technique is a simple, safe, and effective treatment for ULFJLCS.