Sung Jk

Feasibility of C2 translaminar screw as an alternative or salvage of C2 pedicle screws in atlantoaxial instability.

Study Design A retrospective outcome study. Objective The purpose of this study was to analyze the clinical outcomes of our experience with the C2 translaminar screw technique and evaluate its feasibility as an alternative or salvage of the pedicle screw. Summary of Background Data Pedicle screws are the most biomechanically stable screws for use in atlantoaxial fixation. However, in cases with elevated risk of neurovascular complications or failure of screw insertion attempts, a reliable alternative technique is required. Methods Fourteen patients with atlantoaxial instability underwent posterior fixation with C2 translaminar screws. Indications included traumatic instability, atlantoaxial subluxation, os odontoideum, and fusion failure after anterior fixation of a type II odontoid process fracture. A total of 26 screws were inserted and all patients were assessed both clinically and radiographically. Results No procedure-related complications or hardware failures were observed during the follow-up. Postoperative computed tomographic scans revealed laminar breach in 3 patients and none of these resulted in neurological symptoms. Radiographically demonstrated bony fusion was established in 11 patients (91.7%) at follow-up over 6 months, and 5 patients with initial neurological deficit demonstrated at least 1 grade improvement by Frankel grade. Conclusions C2 translaminar screws provide surgeons with an expanded option for posterior fusion in high cervical lesions. This technique is safe and easy to adopt with a favorable rate of successful fusion. We believe that preoperative planning using computed tomographic scan is mandatory and use of an additional connector may reduce the stress and strain of the screws.

The Neuroprotective Effect of Treatment of Valproic Acid in Acute Spinal Cord Injury

Objective Valproic acid (VPA), as known as histone deacetylase inhibitor, has neuroprotective effects. This study investigated the histological changes and functional recovery from spinal cord injury (SCI) associated with VPA treatment in a rat model. Methods Locomotor function was assessed according to the Basso-Beattie-Bresnahan scale for 2 weeks in rats after receiving twice daily intraperitoneal injections of 200 mg/kg VPA or the equivalent volume of normal saline for 7 days following SCI. The injured spinal cord was then examined histologically, including quantification of cavitation. Results Basso-Beattie-Bresnahan scale scores in rats receiving VPA were significantly higher than in the saline group (p<0.05). The cavity volume in the VPA group was significantly reduced compared with the control (saline-injected) group (p<0.05). The level of histone acetylation recovered in the VPA group, while it was significantly decreased in the control rats (p<0.05). The macrophage level was significantly decreased in the VPA group (p<0.05). Conclusion VPA influences the restoration of hyperacetylation and reduction of the inflammatory reaction resulting from SCI, and is effective for histology and motor function recovery.

Risk Factors and Incidence for Peripheral Arterial Disease in Patients with Typical Lumbar Spinal Stenosis

Objective Intermittent claudication (IC) is a typical symptom of peripheral arterial disease (PAD) and lumbar spinal stenosis (LSS). In order to prevent misdiagnosis of vascular disease, it is important to know the incidence of and risk factors for PAD in patients with LSS. Therefore, the aim of our study was to evaluate the incidence of and risk factors for PAD in patients with typical and severe LSS who underwent spinal surgical treatment. Methods The occurrence of PAD was examined retrospectively in 171 consecutive patients with LSS and severe IC who underwent surgical treatment at our hospital from June 2012 to June 2013. Data were collected on background characteristics (sex, age) and known risk factors for PAD, such as hypertension, diabetes mellitus, smoking, hyperlipidemia, stroke, and ischemic heart disease. Results Of the 171 patients enrolled, 7 had an abnormal ankle-brachial index (ABI). Computed tomography angiography (CTA) was performed in these patients, and a final diagnosis of PAD was established for all 7 patients. The incidence of PAD in all patients with LSS was 4.1%(7 of 171). Stroke and ischemic heart disease were significantly more common in the LSSPAD group compared with the LSS group. Multiple logistic regression analyses with a forced-entry method revealed that age and stroke (p<0.05) were independent risk factors for PAD. Conclusion To prevent misdiagnosis of fatal PAD, we recommend ABI be assessed in patients with LSS and history of stroke.

Predictable Factors for Dural Tears in Lumbar Burst Fractures with Vertical Laminar Fractures

OBJECTIVEnThe purpose of the present study was to determine the incidence of dural tears and predictable factors suggesting dural tears in patients who had lumbar burst fractures with vertical laminar fractures.nnnMETHODSnA retrospective review was done on thirty-one patients who underwent operative treatment for lumbar burst fractures with vertical laminar fractures between January 2003 and December 2008. All patients were divided into two groups according to existence of dural tears, which were surgically confirmed; 21 patients with dural tears and 10 patients without dural tears. Clinical and radiographic findings were analyzed for their association with dural tears.nnnRESULTSnAmong a total of 31 patients, dural tears were detected in 21 (67%) patients. A preoperative neurological deficits and mean separation distances of the edges in laminar fractures were found to be the reliable factors of dural tears (p=0.001 and 0.002, respectively). Decreased ratio of the central canal diameter and interpedicular distance were also the reliable factors suggesting dural tears (p=0.006 and 0.015, respectively). However, dural tears showed no significant association with age, sex, level of injury, absence of a posterior fat pad signal, the angle of retropulsed segment, or site of laminar fracture.nnnCONCLUSIONnOur study of lumbar burst fracture combined laminar fracture revealed that dural tears should be ruled out in cases of a preoperative neurological deficits, wide separation of the laminar fracture, severe canal encroachment, and wider interpedicular distance.