Ali Nourbakhsh

Operative versus nonoperative management of acute odontoid Type II fractures: a meta-analysis

OBJECT The purpose of this study was to evaluate the feasibility of the criteria described in the literature as the indications for surgery for acute Type II odontoid fractures. METHODS The authors searched the PubMed database for studies in which the fusion rate of acute Type II odontoid fractures following external immobilization (halo vest or collar) or surgery (posterior C1-2 fusion or anterior screw fixation) was reported. The only studies included reported the fusion rate for either 1) groups of patients whose age was either more or less than a certain age range (45-55 years); or 2) groups of patients with a fracture displacement of either more or less than a certain odontoid fracture displacement (4-6 mm) or the direction of displacement (see Methods section of text for more details). A meta-analysis in which the random effect model was used was conducted to analyze the data. RESULTS There was a statistically significantly higher fusion rate for operative management compared with external immobilization (85 vs 60%, p = 0.01) for the patients > 45-55 years. However, the overall fusion rate was > 80% for the patients whose age was < 45-55 years, regardless of treatment modality, and no significant differences were observed between surgically and nonsurgically treated patients (89 and 81%, respectively; p = 0.29). The result of operation (overall fusion rate 89%) was superior to external immobilization (44%) when the fracture was posteriorly displaced (p < 0.001), but for anteriorly displaced fractures, the results of operative and nonoperative management were identical (p = 0.15). The overall fusion rate of operative management of both anteriorly and posteriorly displaced fractures proved to be > 85%, and no statistically significant difference was observed (p = 0.50). For all degrees of displacement (either > or < 4-6 mm) the operation proved to provide significantly better results than conservative treatment. The fusion rate of conservatively treated fractures with < 4-6 mm displacement was significantly better than in fractures with > 4-6 mm displacement (76 vs 41%, p = 0.002). CONCLUSIONS Operative treatment (posterior C1-2 fixation or anterior screw fixation) provides a better fusion rate than external immobilization for acute odontoid Type II fractures, although in certain situations, such as anterior displacement of the fracture and for younger (< 45-55 years of age) patients, conservative management (halo vest or collar immobilization) can be as effective as surgery. Operative management is recommended in older patients, in cases of posterior displacement of the fracture, and when there is displacement of > 4-6 mm.

Percutaneous spine biopsy: a meta-analysis

BACKGROUND Percutaneous spine biopsy has widely replaced open biopsy. We conducted a meta-analysis to evaluate the effect of the inner diameter of the biopsy needle and the method of imaging guidance on the adequacy and accuracy of tissue samples and to evaluate the complication rates associated with the different needle diameters and imaging guidance methods. METHODS We searched MEDLINE for studies that evaluated either the adequacy (whether or not a diagnosis could be made on the basis of pathologic examination) or the accuracy (whether or not the primary diagnosis was correct) of samples obtained by means of percutaneous spine biopsy. These articles and their relevant references subsequently were reviewed twice and were evaluated against the inclusion criteria, yielding twenty-five studies. The inclusion criterion was the use of a biopsy instrument (a fine needle or trephine with an identifiable inner diameter) under the guidance of imaging (fluoroscopy or computed tomography) for the evaluation of an identified spine lesion, with the report of either adequacy or accuracy. Meta-analysis with use of the random-effects model was used to analyze the data. RESULTS The adequacy, accuracy, and complication rates increased with the inner diameter of the needles, but, with the numbers available, only the complication rate increased significantly (p = 0.01). Although the use of a computed tomography scan slightly increased the adequacy and accuracy of the samples, these increases were not significant. The complication rate associated with the use of computed tomography was 3.3%, compared with 5.3% for fluoroscopy. CONCLUSIONS As the outcomes associated with computed tomography were not significantly different from those associated with fluoroscopy, the decision to use one or the other requires the consideration of other factors, such as the type, level, and vertebral location of the lesion as well as the expertise of the physician. In situations in which the use of a needle with a small inner diameter is highly effective (for example, in cases of metastatic lesions), the clinician should first consider using a needle with a smaller inner diameter to obtain the biopsy specimen because of the higher complication rate associated with large-bore needles. However, in cases of sclerotic lesions, in which obtaining an adequate sample can be difficult, the use of a needle with a larger inner diameter is desirable.

Esophageal perforation with a locking screw: a case report and review of the literature.

Study Design. A case report with a review of the literature. Objectives. Anterior cervical spine surgery (ACS) has received widespread acceptance, and as a result, a variety of complications have been reported. Several cases of esophageal complications, arising from the use of various implants and grafts, have been described. The purpose of this article is to provide insight into the clinical presentation, diagnosis, types of involved implants, and the treatment of this entity. Summary of Background Data. Previous reports of esophageal complications (esophageal perforation, diverticula, and stricture) after ACS are reviewed. Methods. Retrospective case study and literature review. Results. Redundant locking screws should be removed due to the potential for extrusion into the esophagus. Conclusions. Regular, long-term follow-up of the patient undergoing anterior spine surgery is crucial. The wide range of possible complications mandates thorough workup. Early surgical treatment is imperative in the majority of esophageal complications.

Lumbar synovial joint hematoma in a patient on anticoagulation treatment.

Study Design. Case report. Objective. To describe a case of spinal epidural hematoma arising from the synovial joint due to anticoagulation therapy. Summary of Background Data. Spontaneous spinal epidural hematoma is a rarity in the literature with a variety of etiologies. In 1 study, it was reported to originate from a synovial joint due to osteoarthritis of the joint. Methods. A case of hematoma of the lumber synovial joint is presented. Results. A 67-year-old man who was on anticoagulation therapy presented with progressive neurologic symptoms in the right lower limb. Magnetic resonance imaging scan revealed what was thought to be a L4–L5 synovial joint cyst. During surgery, it was proven to be an epidural hematoma originating from the synovial joint. Microscopic examination confirmed the diagnosis and excluded the possibility of spinal synovial cyst. After spinal decompression, neurologic symptoms improved completely in 2 weeks. Conclusions. This is the first report of a synovial cyst hematoma due to anticoagulation therapy. Its magnetic resonance imaging features can be similar to synovial cyst, especially when it is hemorrhagic. Spinal decompression was the definitive treatment.

A Comparison of the Torsional Stiffness of the Lumbar Spine in Flexion and Extension

OBJECTIVE The main mechanism of injury to the spine is torsion especially when coupled with compression. In this study, the in vitro torsional stiffness of the lumbar spine segments is compared in flexion and extension positions by cyclic and failure testing. METHODS Fifteen lumbar spines were sectioned from fresh cadavers into 15 L2/3 and 15 L45 motion segments. Each vertebral segment was then potted superiorly and inferiorly in polymethylmethacrylate, effectively creating a bone-disk-bone construct. The potted spinal segments were mounted in a mechanical testing system, preloaded in compression to 300 N, and axially rotated to 3 degrees in both directions at a load rate of 1 degrees /s. This was done over 3 cycles for each motion segment in the flexion and extension positions. Each specimen was then tested to torsional failure in either flexion or extension. Stiffness, torque, and energy were determined from cyclic and failure testing. RESULTS The results showed that in all cases of cyclic testing, the higher segment extension resulted in higher torsional stiffness. In relative extension, the lumbar specimens were stiffer, generated higher torque values, and generally absorbed more energy than the relative flexion condition. There were no differences found in loading direction or failure testing. CONCLUSIONS Increasing the effective torsional stiffness of the lumbar spine in extension could provide a protective mechanism against interverbral disk injury. Restoration of segmental extension through increasing the lumbar lordosis may decrease the strain and reinjury of the joints, which can help reduce the extent of pain in the lumbar spine.

Readmission Rates, Reasons, and Risk Factors in Elderly Patients Treated With Lumbar Fusion for Degenerative Pathology

Study Design. Retrospective database review. Objective. To determine readmission rates after 1 to 2 level, primary, elective lumbar spinal fusion surgery for degenerative pathology and elucidate risk factors that predict increased risk of 30-day readmission Summary of Background Data. Early postoperative readmissions after spine surgery represent a significant source of increased cost and morbidity. As the elderly population represents a demographic with a growing need for spine surgery, readmissions within this population are of significant interest. Methods. Medicare data (2005–2012) from an insurance database was queried for patients who underwent primary 1 to 2 level posterolateral lumbar spine fusion surgeries for degenerative lumbar pathology. After applying specific exclusion criteria to select for elderly patients (65–84 yr) undergoing mostly elective procedures, 52,567 patients formed the final study population. Readmission rates for medical, surgical, and all reasons were calculated within 30 days, 90 days, and 1 year postoperatively. Risk factors for medical, surgical, and all 30-day readmissions were also determined. Results. Within 30 days, 90 days, and 1 year, 1510 (2.9%), 2776 (5.3%), and 6574 (12.5%) patients were readmitted, respectively. At 30 days, surgical diagnoses constituted 50.1% of all readmissions. Wound infection was the reason for readmission in 25.8% of all readmissions within 30 days. Diagnoses of chronic pulmonary disease (OR 1.41 95% CI 1.22–1.63), obesity (OR 2.20 95% CI 1.90–2.54), and positive smoking history (OR 1.33 95% CI 1.15–1.54) were associated with increased risk of surgical readmission. Conclusion. Elderly patients undergoing lumbar spine fusion experience 30-day, 90-day, and 1-year readmission rates of 2.9, 5.3, and 12.5% for both medical and surgical reasons. Surgical site infection and wound complications are the most common surgery-related reasons for readmission. Medical diagnoses are more predominant during later readmissions, highlighting the comorbidity burden present in elderly patients. Level of Evidence: 4

Intracerebral metastasis of a sinonasal teratocarcinosarcoma: a case report.

Sinonasal teratocarcinosarcoma (SNTCS) is a rare, malignant neoplasm that contains both mesenchymal and epithelial components. The mortality rate for this tumor is ∼60% within 3 years, with the average survival rate being 1.7 years. Usually, this neoplasm presents with symptoms of nasal obstruction and epistaxis. Neurological symptoms from intracranial extension and dural invasion are rare presentations for this neoplasm. We present the first known case of an intracerebral metastasis of a previously resected SNTCS.

The use of bioabsorbable screws to fix Type II odontoid fractures: a biomechanical study

OBJECT Anterior screw fixation of the Type II odontoid fracture stabilizes the odontoid without restricting the motion of the cervical spine. The metal screw may limit bone remodeling because of stress shielding (if not placed properly) and limit imaging of the fracture. The use of bioabsorbable screws can overcome such shortcomings of the metal screws. The purpose of this study was to compare the strength of a 5-mm bioabsorbable screw with single 4-mm metal and double 3.5-mm lag screw fixation for Type II fractures of the odontoid process. METHODS Three different modalities of anterior screw fixation were used in 19 C-2 vertebrae. These fixation methods consisted of a single 5-mm cannulated bioabsorbable lag screw (Group A), a single 4-mm cannulated titanium lag screw (Group B), and two 3.5-mm cannulated titanium lag screws (Group C). Anteroposterior (AP) stiffness and rotational stiffness were evaluated in all constructs. RESULTS There was no statistical difference among the ages of the cadavers in each group (p = 0.52). The AP bending stiffness in Groups A, B, and C was 117 ± 86, 66 ± 43, and 305 ± 130 Nm/mm, respectively. The AP bending stiffness in Group C was significantly higher than that in Groups A and B (p = 0.01 and p = 0.001, respectively). The difference in AP bending stiffness values of bioabsorbable and 4-mm metal screws was not statistically significant (p = 0.23). The rotational stiffness of the double 3.5-mm metal screws was significantly greater than that of the 5-mm bioabsorbable and the 4-mm titanium screws. CONCLUSIONS Double screw fixation with 3.5-mm screws provides the stiffest construct in Type II odontoid fractures. Bioabsorbable lag screws (5 mm) have the same AP bending and rotational stiffness as the single titanium lag screw (4 mm) in odontoid fractures.

Feasibility of thoracic nerve root preservation in posterior transpedicular vertebrectomy with anterior column cage insertion: a cadaveric study.

OBJECT Transpedicular thoracic vertebrectomy (TTV) is a safe alternative to the more standard transthoracic approach. A TTV is most commonly used to address vertebral body fractures due to tumor or trauma. Transpedicular reconstruction of the anterior column with cage/bone traditionally requires unilateral thoracic nerve root sacrifice. In a cadaveric model, the authors evaluated the feasibility of transpedicular anterior column reconstruction without nerve root sacrifice. If feasible, this may be a reasonable approach that could be extended to the lumbar spine where nerve root sacrifice is not an option. METHODS A TTV was performed in 8 fixed cadaveric specimens. In each specimen, an alternate vertebra (either odd or even) was removed so that single-level reconstruction could be evaluated. The vertebrectomy included facetectomy, adjacent discectomies, and laminectomy; however, the nerve roots were preserved. The authors then evaluated the feasibility of inserting a titanium mesh cage (Medtronic Sofamor Danek) without neural sacrifice. RESULTS Transpedicular anterior cage reconstruction could be safely performed at all levels of the thoracic spine without nerve root sacrifice. The internerve root space varied from 18 mm at T2-3 to 27 mm at T11-12; thus, the size of the cage that was used also varied with level. CONCLUSIONS Cage reconstruction of the anterior column could be safely performed via the transpedicular approach without nerve root sacrifice in this cadaveric study. Removal of the proximal part of the rib in addition to a standard laminectomy with transpedicular vertebrectomy provided an excellent corridor for anterior cage reconstruction at all levels of the thoracic spine without nerve root sacrifice.

Spontaneous Cervical Epidural Hematoma Masquerading as an Abscess on Magnetic Resonance Imaging Scan

OBJECTIVE The aims of the study are to describe a case of spontaneous spinal epidural hematoma (SSEH) without any predisposing factors and magnetic resonance imaging (MRI) features of epidural abscess and to highlight the importance of high clinical suspicion. CLINICAL FEATURES A 75-year-old male presented to the emergency department after a severe neck pain. He progressively showed sensory and upper motor signs on the left side of the body. The MRI scans were suggestive of cervical epidural abscess with peripheral enhancement of the lesion. INTERVENTIONS AND OUTCOMES He underwent a multiple level (C3-T1) laminectomy when he was found to have an SSEH. There has been no history of trauma or other predisposing factor, and presence of arteriovenous malformation was ruled out by MR angiography. CONCLUSIONS The MRI features of SSEH may be misleading and mimic other spinal lesions such as abscess. Presence of tapering superior and inferior margins, spotty Gadolinium enhancement in the mass, along with abrupt clinical onset of pain and neurologic deficit, should raise the suspicion toward epidural hematoma. Enhancement in the hyperacute stage of the hematoma itself might indicate continued bleeding and, in the case of deteriorating neurologic status, will necessitate decompression.