Ligamentous Augmentation to Prevent Proximal Junctional Kyphosis and Failure: A Biomechanical Cadaveric Study.

STUDY DESIGN: Biomechanical cadaveric study (level V). OBJECTIVE: To evaluate the effectiveness of polyethylene bands looped around the supra-adjacent spinous process (SP) or spinal lamina (SL) in providing strength to the cephalad unfused segment and reducing junctional stress. BACKGROUND: Proximal junctional kyphosis (PJK) is a pathologic kyphotic deformity adjacent to posterior spinal instrumentation after fusion constructs. Recent studies demonstrate a mismatch in stiffness between the instrumented construct and nonfused adjacent levels to be a causative factor in the development of PJK and proximal junction failure. To our knowledge, no biomechanical studies have addressed the effect of different methods of polyethylene band placement at the proximal junction. MATERIALS AND METHODS: Twelve fresh frozen cadavers were divided into 3 groups of 4: pedicle screw-based instrumentation from T10 to L5 ("control"), T10-L5 instrumentation with a polyethylene band to the T9 "SP," T10-L5 instrumentation with 2 polyethylene bands to the T9 "SL." Specimens were tested with an eccentric (10 mm anterior) load at 5 mm/min for 15 mm or until failure occurred. Failure was defined by the inflection point on the load versus deformation curves. Linear regression was utilized to evaluate the effect of augmentation on the load-to-failure. Significance was set at 0.05. RESULTS: Fractures occurred in all specimens tested. The mean peak load to failure was 2148 N (974-3322) for the SP group, and 1248 N (742-1754) for the control group (P > 0.05) and 1390 N (1080-2004) for the SL group. No difference existed between the control group and the SP group in terms of fracture level (P > 0.05). Net kyphotic angulation shows no differences among these 3 groups (P > 0.05). CONCLUSION: Although statistical significance was not achieved, ligament augmentation to the SP increased mean peak load-to-failure in a cadaveric PJK model.

Traumatic Lumbosacral Dislocation: Current Concepts in Diagnosis and Management.

Traumatic lumbosacral dislocation is a rare, high-energy mechanism injury characterized by displacement of the fifth lumbar vertebra in relation to the sacrum. Due to the violent trauma typically associated with this lesion, there are often severe, coexisting injuries. High-quality radiographic studies, in addition to appropriate utilization of CT scan and MRI, are essential for proper evaluation and diagnosis. Although reports in the literature include nonoperative and operative management, most authors advocate for surgical treatment with open reduction and decompression with instrumentation and fusion. Despite advances in early diagnosis and management, this injury type is associated with significant morbidity and mortality, and long-term patient outcomes remain unclear.

The Significance of Upper Extremity Neuromonitoring Changes During Thoracolumbar Spine Surgery.

STUDY DESIGN: This is a retrospective matched-pair cohort study. OBJECTIVE: To investigate the significance of upper extremity (UE) neuromonitoring changes in patients undergoing thoracolumbar surgery in prone position. SUMMARY OF BACKGROUND DATA: Peripheral nerve injuries in the UEs due to the prone positioning during prolonged thoracolumbar spinal procedures can cause diminished postsurgical outcomes. Intraoperative neuromonitoring has been utilized to alert the surgeon of the development of such injuries. MATERIALS AND METHODS: Patients who developed intraoperative ulnar somatosensory-evoked potential (SSEP) signal changes during posterior thoracolumbar surgery were identified and compared with a group of patients who did not develop such signal changes. The patients in 2 groups were pair-matched on the number of vertebral levels undergoing surgery. Data regarding intraoperative attempts to resolve signal changes and outcomes were collected. RESULTS: In total, 843 patients underwent thoracic, lumbar, or thoracolumbar spine surgeries in the prone position with intraoperative ulnar SSEPs neuromonitoring data available. Of these, 37 patients (4.4%) had intraoperative signal changes in the UEs. An equal number of patients without signal changes were also selected. In each group, 6 patients underwent thoracic, 20 patients underwent lumbar, and 11 patients underwent thoracolumbar procedures. In 8 patients (21.6%), there was no resolution of SSEP signal changes despite intraoperative attempts. The 2 groups were similar with respect to age and comorbidities. There was no significant difference in the mean body mass index (P=0.22). The mean duration of the procedures was 324 minutes in the SSEP signal change patients and 260 minutes in the patients without SSEP signal changes (P=0.03). No patient with UE SSEP changes had a clinically detectable neurological deficit postoperatively. CONCLUSIONS: UE SSEP signal changes during multilevel posterior thoracolumbar procedures are more likely to occur as the duration of the operation increases. The presence of UE signal changes does not coincide with clinically significant peripheral neuropathies. LEVEL OF EVIDENCE: Level III.

Type III odontoid fractures: A subgroup analysis of complex, high-energy fractures treated with external immobilization.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Type III odontoid fractures are classically treated nonoperatively, yet, the current literature on Type III odontoid fractures includes fractures of multiple etiologies and fracture morphologies. We hypothesize that a subgroup of complex, Type III fractures caused by high-energy mechanisms are more likely to fail nonoperative treatment. MATERIALS AND METHODS: Acute Type III odontoid fractures were identified at a single institution from 2008 to 2015. Fractures were categorized as high- or low-energy fracture with high-energy fractures defined as those with lateral mass comminution (>50%) or secondary fracture lines into the pars interarticularis or vertebral body. Patients were treated in either a hard collar orthosis or halo vest and were followed for fracture union and stability. RESULTS: One hundred and twenty-five Type III odontoid fractures were identified with 51% classified as complex fractures. Thirty-three patients met the inclusion and exclusion criteria including 15 patients treated in a halo vest and 18 in a hard collar orthosis. Mean follow-up was 32 (±44) weeks. Seven patients demonstrated progressive displacement of either 2 mm of translation or 5° of angulation and underwent delayed surgical stabilization. Two additional patients required delayed surgery for nonunion and myelopathy. Initial fracture displacement and angulation were not correlative with final outcome. No statistical advantage of halo vest versus hard collar orthosis was observed. CONCLUSIONS: Complex Type III odontoid fractures are distinctly different from low-energy injuries. In the current study, 21% of patients were unsuccessfully treated nonoperatively with external immobilization and required surgery. For complex Type III fractures, we recommend initial conservative treatment, while maintaining close monitoring throughout patient recovery and fracture union.

Unstable C1 Fracture Managed with Internal Fixation Using Lateral Mass Screws: A Case Report.

CASE: A 47-year-old woman presented with an unstable C1 fracture after falling down several stairs. She was found to have a sagittal split fracture of the right C1 lateral mass extending into the posterior arch. The fracture was treated with a direct posterior osteosynthesis of C1 using lateral mass screws. CONCLUSION: Surgical management of unstable C1 fractures has traditionally involved posterior fusion of C1 to C2 or fusion from the occiput to C2. These fusion procedures can be quite functionally limiting. Recently, direct osteosynthesis of C1 has been shown to be an effective, motion-preserving alternative.

Clinical and Radiologic Outcomes After Fenestration and Partial Wall Excision of Idiopathic Intradural Spinal Arachnoid Cysts Presenting with Myelopathy.

BACKGROUND: Intradural spinal arachnoid cysts (ISACs) with associated neurologic deficits are encountered infrequently. Various management strategies have been proposed with minimal data on comparative outcomes. OBJECTIVE: We describe the clinical and radiologic presentation as well as the outcomes of 14 surgically managed patients who presented with an ISAC and associated myelopathy. METHODS: We retrospectively reviewed the clinical course of consecutive patients presenting with neurologic deficits associated with idiopathic ISACs at our institution. The diagnoses were based on preoperative magnetic resonance imaging studies followed by intraoperative and histopathological confirmation. RESULTS: A total of 14 consecutive patients with ISACs (1 cervicothoracic, 12 thoracic, and 1 thoracolumbar) and associated myelopathy were identified. Syringomyelia was noted in 8 patients. All ISACs were treated with cyst fenestration and partial wall resection through a posterior approach. Preoperative neurologic symptoms were noted to be stable or improved in all patients starting at 6-week postoperative follow-up. The median (interquartile range) preoperative mJOA score was 13 (12.0-14.8), whereas the postoperative median score at a mean follow-up of 22 months (range 6-50 months) was 16 (14.0-17.0), which represents a median improvement (ΔmJOA) of 2.0 (1.3-3.0) (P < 0.001). Comparison of ΔmJOA scores between cases without and with associated syrinxes did not reveal a significant difference (P = 0.23). Postoperative magnetic resonance imaging scans revealed spinal cord re-expansion at the level of the ISAC in all cases and either complete or partial syrinx resolution in 7 of 8 cases. CONCLUSIONS: Early treatment with fenestration and partial wall resection allows for cord decompression, syrinx resolution, and gradual resolution of myelopathic symptoms in most cases.

Early, reliable, utilitarian predictive factors for fat embolism syndrome in polytrauma patients.

BACKGROUND: Fat embolism is one of the apocalyptic pulmonary complications following high energy trauma situations. Since delay in diagnosis may have devastating consequences, early, easily accessible and relatively inexpensive investigations for risk stratification may prove useful, especially in developing nations. MATERIALS AND METHODS: This prospective trial included a total of 67 young polytrauma patients, in whom the role of nine easily available, rapidly performable clinical or laboratory investigations (or observations noted at admission) in predicting the later occurrence of fat embolism syndrome were assessed. All the patients also underwent continuous monitoring of oxygen saturation with pulsoximetry. RESULTS: The correlation between initial serum lactate (within 12 hours of injury) and hypoxia was statistically significant. There was a trend towards correlation with FES(by Gurd's criteria) (P=0.07), Sensitivity of 24-hour monitoring of oxygen saturation in predicting later pulmonary deterioration approached 100%. CONCLUSIONS: The combination of three factors including polytrauma (with NISS >17), serum lactate >22 mmol/l at admission (within 12 hours of injury) fall in oxygen saturation (SaO2 below 90% in the initial 24 hours) predict the development of post-traumatic pulmonary complications, especially the fat embolism syndrome.

Risk of postoperative venous thromboembolism in Indian patients sustaining pelvi-acetabular injury.

Most surgeons believe that Asians have a low risk of developing venous thromboembolism (VTE) and routine thromboprophylaxis therapy is not required after major orthopaedic trauma. This study evaluates the postoperative risk of VTE in Indian patients sustaining pelvi-acetabular injury. Fifty-six patients with pelvi-acetabular injury, who underwent open reduction and internal fixation, were prospectively evaluated for VTE in the postoperative period. They were evaluated, both clinically and radiologically (pulmonary CT angiography and indirect venography of lower limb and pelvis veins), until six weeks after surgery. A total of 16 patients developed VTE, of which 12 had proximal deep vein thrombosis (DVT), ten had pulmonary embolism (PE) and only two had distal DVT. Six patients with proximal DVT had associated PE. The risk of development of VTE among Indian patients after pelvi-acetabular injury is high (28.6%) with increasing chances of proximal DVT and PE; hence, administration of routine thromboprophylaxis is fully justified in them.