Object The increasing incidence of spinal metastasis, a result of improved systemic therapies for cancer, has spurred a search for an alternative method for the surgical treatment of lumbar metastases. The authors report a single-stage posterior-only approach for resecting any pathological lumbar vertebral segment and reconstructing with a medium to large expandable cage while preserving all neurological structures. Methods The authors conducted a retrospective consecutive case review of 11 patients (5 women, 6 men) with spinal metastases treated at 1 institution with single-stage posterior-only vertebral column resection and reconstruction with an expandable cage and pedicle screw fixation. For all patients, the indications for operative intervention were spinal cord compression, cauda equina compression, and/or spinal instability. Neurological status was classified according to the American Spinal Injury Association impairment scale, and functional outcomes were analyzed by using a visual analog scale for pain. Results For all patients, a circumferential vertebral column resection was achieved, and full decompression was performed with a posterior-only approach. Each cage was augmented by posterior pedicle screw fixation extending 2 levels above and below the resected level. No patient required a separate anterior procedure. Average estimated blood loss and duration of each surgery were 1618 ml (range 900-4000 ml) and 6.6 hours (range 4.5-9 hours), respectively. The mean follow-up time was 14 months (range 10-24 months). The median survival time after surgery was 17.7 months. Delayed hardware failure occurred for 1 patient. Preoperatively, 2 patients had intractable pain with intact lower-extremity strength and 8 patients had severe intractable pain, lower-extremity paresis, and were unable to walk; 4 of whom regained the ability to walk after surgery. Two patients who were paraplegic before decompression recovered substantial function but remained wheelchair bound, and 2 patients remained paraparetic after the surgery. No patients had lasting intraoperative neuromonitoring changes, and none died. Complications included 2 reoperations, 1 delayed hardware failure (cage subsidence that did not require revision), and 3 incidental durotomies (none of which required reoperation). No postoperative pneumonia, ileus, or deep venous thrombosis developed in any patient. Conclusions A posterior-only approach for vertebral segment resection with preservation of spinal nerve roots is a viable technique that can be used throughout the entire lumbar spine. Extensive mobilization of the nerve roots is of utmost importance and allows for insertion and expansion of medium-sized, in situ expandable cages in the midline. This approach, although technically challenging, might reduce the morbidity associated with an anterior approach.

Object Surgery of intramedullary tumors is established as the treatment of choice for these challenging lesions. This study presents a detailed analysis of risk factors for surgical morbidity and data on long-term results for intramedullary tumors. Methods Among 1317 patients with tumors of the spinal canal treated between 1980 and 2012, 278 patients with intramedullary tumors are presented. A total of 225 of these patients underwent 246 operations for treatment of 250 tumors. The mean patient age was 41 ± 17 years (range 3 weeks to 83 years). Patients underwent follow-up through outpatient visits and questionnaires with a mean follow-up of 41 ± 53 months. Tumors were subdivided into 3 groups: displacing tumors (Type A, n = 162), infiltrating tumors (Type B, n = 80), and nonproliferating tumors (Type C, n = 8). A gross-total resection (GTR) was attempted for every tumor except for Type C lipomas. Participating surgeons were divided into 3 groups according to the number of operations they performed. Short-term results were determined for individual symptoms and the modified McCormick Scale, whereas tumor recurrence rates were calculated with Kaplan-Meier statistics. Results Overall, 83.3% of Type A tumors underwent GTR compared with 22.5% of Type B and none in Type C. Gross-total resection rates increased throughout the study period and correlated significantly with surgical experience. A worsened neurological state after surgery was seen in 61% of patients. This deterioration was transient in 41.5% and was a common observation after GTR. Permanent morbidity (19.5%) was lowest after GTR and correlated significantly with surgical experience and the preoperative neurological state. Further analysis showed that patients with tumors of thoracic levels, tumor hemorrhages, and malignant and recurrent tumors were at a higher risk for permanent morbidity. In the long term, tumor recurrence rates for ependymomas and benign astrocytomas correlated significantly with the amount of resection. Long-term morbidity affected 3.7% with a postoperative myelopathy related to cord tethering at the level of surgery and 21.9% in form of neuropathic pain syndromes. The rate of postsurgical cord tethering could be lowered significantly by using pia sutures after tumor resection. Neuropathic pain syndromes were more common after surgery for tumors with associated syringomyelia or those located in the cervical cord. Conclusions Intramedullary tumors should be surgically treated as soon as neurological symptoms appear. Gross-total resection is possible for the majority of benign pathologies. Cervical tumors are associated with higher GTR and lower permanent morbidity rates compared with thoracic tumors. Surgery on intramedullary tumors should be performed by neurosurgeons who deal with these lesions on a regular basis as considerable experience is required to achieve high GTR rates and to limit rates of permanent morbidity.

Object The authors describe the clinical presentation, imaging features, and management of patients presenting with filum terminale arteriovenous fistulas (FTAVFs) and the role of transarterial treatment in their management. Methods The authors retrospectively reviewed data obtained in 10 patients with FTAVFs diagnosed between January 1990 and December 2011. Results Most patients (70%) were male, and the age of the population ranged from 31 to 72 years (mean 58.2 years). Clinical presentation was progressive paraparesis and sensory loss in the lower extremities in 9 cases, back pain in 7, radicular pain in 3, bowel/bladder disturbance in 5, and impotence in 1. The duration of symptoms varied between 2 and 24 months. Initial MRI studies showed intramedullary increased T2 signal, swollen cord, and dilated perimedullary veins in all patients. One patient had syringomyelia, presumably caused by venous hypertension transmitted by the perimedullary venous system. Embolization was attempted in 7 patients and was curative in 6 patients. Surgery was performed in the other 4 patients in whom embolization was unsuccessful or deemed not feasible. There was no treatment-related complication in either group. Symptoms, venous congestion in the cord, and syringomyelia improved on follow-up in all patients. Conclusions Embolization should be considered the treatment of choice for FTAVFs and can effectively treat the majority of patients presenting with an FTAVF. In a smaller group of patients in whom the angioarchitecture is unfavorable, open surgery is recommended.

Study Design. Retrospective analysis of kinetic magnetic resonance images (kMRIs).

Objective.

To define the prevalence of degenerative cervical spondylolisthesis in symptomatic patients and to analyze the motion characteristics and influence on the spinal canal at the affected level.Summary of Background Data. When compared to lumbar spondylolisthesis, there are few studies evaluating cervical spondylolisthesis, and the prevalence and motion characteristics of cervical spondylolisthesis are not well defined.Methods. Four hundred and sixty-eight symptomatic patients underwent upright cervical kMRI in neutral, flexion, and extension positions. Segmental displacement and intervertebral angles were measured in three positions using computer analysis software. Spondylolisthesis was defined as the vertebral displacement more than 2mm, and graded based on the magnitude into two groups at each level: Grade 1 (2-3 mm), Grade 2 (>3 mm). Instability was defined as segmental translational motion exceeding 3 mm.

Results.

Grade 1and 2 spondylolisthesis at a minimum of one level were observed with a prevalence of 16.4 and 3.4% of all patients, respectively. The most affected levels were C4/5 (6.2%) and C5/6 (6.0%) followed by C3/4 (3.6%) and C6/7 (3.0%). Translational motion was greater in levels with Grade 1 as compared with segments without spondylolisthesis, but there was no difference in angular motion between the three groups. Translational instability was observed with a prevalence of 16.7% in Grade 2, 4.3% in Grade 1, and 3.4% in segments without spondylolisthesis. Space available for the cord at the affected level was decreased and spinal cord compression grade was higher in Grade 1 and Grade 2 as compared to levels without spondylolisthesis.

Conclusion.

Cervical spondylolisthesis of at least 2 mm was observed in 20% of patients and was most common at C4/5 and C5/6. The presence of spondylolisthesis was associated with increased translational motion and decreased segmental spinal canal diameter.

Study Design. Retrospective

Objective.

To critically assess if cross-links are necessary adjuvants in posterior spinal-constructs.Summary of Background Data. Although numerous biomechanical studies are available in the literature, there has been no clinical study that has evaluated the need for cross-links in clinical situations.Methods. The spinal-constructs of patients of varied etiology that underwent surgery between July-2007 and July-2011 without the usage of cross-links were evaluated. The immediate post-operative erect-radiographs were compared with the erect-radiographs at the last follow-up by two independent observers (spine fellows not involved in the management of the patients) critically for any rotational instability using the Nash-Moe technique of assessment of vertebral rotation as well as for any 'parallelogram effect'. The intra-observer and inter-observer reliability was analyzed.

Results.

There were 208 cases included in the study, during the study period; satisfying the criteria. The total number of motion segments fused was 707 ranging from one to 15 involving various etiologies. The average follow-up was 15 months (12 months to 36 months). Barring one patient with a thoraco-lumbar fracture with rotational instability (AO Type C) that had undergone a short-segment fixation, none of the cases demonstrated any rotational instability in the follow-up radiographs. Interestingly, the rotational instability (parallelogram-effect) in that patient got corrected spontaneously once anterior reconstruction was performed. The intra-observer reliability was 100% and the inter-observer reliability was 92.83%. This variability was in assessing the grade of vertebral rotation only; none of the levels had a change in rotation irrespective of variation in grade assessment in the final post-op radiograph.

Conclusion.

This study concludes that utilization of cross-links in clinical practice may be avoidable. The derivations from biomechanical studies do not translate into clinical advantages. Eliminating the usage of cross-links reduces the operative time as well as the over-all total hospital costs (a single cross-link may cost anywhere between $1500 to $2000 and surgeons tend to use single or multiple cross-links). Additionally, prominence of implants, corrosion, infection, implant failure and pseudarthrosis are the other complications attributed to cross-links in the literature that can be eliminated by preventing their incorporation in spinal constructs.

Study Design. Retrospective chart review.

Objective.

To evaluate the outcomes of anterior exposure of the thoracic and lumbar spine by an acute care surgery service.Summary of Background Data. Spine surgeons typically require an "approach surgeon" to provide anterior exposure of the thoracic and lumbar spine. We hypothesized that a dedicated acute care surgery service can perform those operations with acceptable morbidity and mortality.Methods. A retrospective review of 161 trauma and non-trauma patients was performed. All cases were performed at a Level I trauma center with a dedicated acute care surgery service. In-hospital morbidity and mortality were evaluated. The sum of relative value units (RVU) earned by performing those operations was determined. A brief description of the operative techniques used by our group is also provided.

Results.

Of the 161 patients 59 (37%) were trauma patients. Ninety three patients (58%) had anterolateral retroperitoneal exposure of the thoracic and lumbar spine. Sixty eight patients (42%) had anterior retroperitoneal midline exposure of the lumbar and lumbosacral spine. Total morbidity was 9.3% (7.4% for trauma patients and 1.8% for non-trauma patients). Morbidity was highest in patients who had anterolateral exposure of the thoracic and lumbar spine (6.8%). Morbidity in patients who had midline exposure of L4 to S1 was 0%. Total mortality was 1.2% (3.3% for trauma patients and 0% for non-trauma patients). The acute care surgery service gained 3141 physician work RVU's by performing those operations.

Conclusion.

Anterior exposure of the thoracic and lumbar spine both for trauma and non-trauma related indications can be performed with acceptable morbidity and mortality by a dedicated acute care surgery service. Morbidity and mortality were higher in trauma patients and in those who underwent thoracolumbar procedures. Patients who had midline exposure of L4 to S1 for degenerative disc disease had the least morbidity.

Study Design. Retrospective clinical analysis

Objective.

To study proper discontinuation date of aspirin in spinal fusion surgerySummary of Background Data. It is thought that excess bleeding can be normalized if aspirin intake is discontinued approximately 7 days before surgery; however, the average life span of a platelet is generally regarded to be 7 to 10 days.Methods. From January, 2004 to December, 2009, a single surgeon performed 182 cases of one- or two-level lumbar fusion surgeries. Patients who were aspirin users (n = 86) were divided into two groups according to the number of days prior to surgery that they discontinued their aspirin use: the Aspirin1 group discontinued their aspirin use 3 to 7 days before surgery and the Aspirin2 group discontinued their aspirin use 7 to 10 days before surgery. Ninety-six patients who did not use aspirin before surgery were selected for the control group. We retrospectively compared the several hematologic parameters among the two aspirin groups and the control group.

Results.

Both the total amount of drained blood (DB) and the duration of indwelling of the drainage catheter (DD) were significantly less in the control group than in the Aspirin1 groups in patients that underwent either type of one-level fusion surgery. However, those were not significantly different between Aspirin 2 and control group in patients that underwent either type of one-level fusion surgery. Only DD was significantly less in the control group than in the Aspirin1 groups in patients that underwent two-level fusion surgery.

Conclusion.

Only the Aspirin1 group, wherein patients discontinued aspirin use 3 to 7 days before surgery, showed a greater DB and DD than the control group. If aspirin was discontinued 7 days or longer before surgery, there was no difference in the study parameters, compared to the control group.

STRUCTURED

ABSTRACT:

: Study Design. Case report.

Objective.

To present a case of primary hydatid cyst in the lombar subcutaneous tissue affecting posterior paravertebral muscle and mimicking disc herniation.Summary of Background Data. Cystic Hydatid Disease is a rare but significant parasitic disease in endemic areas. Musculoskeletal or soft tissue hydatidosis accounts for about 0,5-5% of all echinococcal infections in endemic areas and is almost secondary to the hepatic or pulmonary disease. Primary lomber subcutaneous hydatid cyst affecting paravertebral muscle and extending to neural foramina is a very rare condition even in endemic areas.Methods. A 25 year-old female patient was admitted with swelling and pain in the right lumbar region for three months. The pain was reflecting in the right gluteal region and the right leg. Lumbar extension and right lateral flexion was painful and straight leg raising test was positive at right side. There was a mild hypoesthesia at L5 dermatome. According to the magnetic resonance imaging which the clinician requested for initial diagnosis of lumbar disc herniation we find multi-cystic masses located at the right paravertebral muscle at the level of L3-5 and extends to L4-5 neural foramina and at subcutaneous tissue at the riht gluteal region.

Results.

The patient was operated for the purpose of removal of cysts. Postoperatively, diagnosis of hydatid cyst was confirmed by histopathology.

Conclusion.

By this case, we emphasize that cystic hydatid disease should be taken into consideration in the differential diagnosis of low back pain and could mimic disc herniation.

Study Design. Case report.

Objective.

Present a previously unreported complication of subarachnoid hemorrhage and hydrocephalus after C1 lateral mass screw insertion to inform spine specialists of this potential post-operative complication.Summary of Background Data. Damage to the carotid artery, vertebral artery, hypoglossal nerve and dural tears are all recognized complications. Acute hydrocephalus as a result of subarachnoid hemorrhage is not previously reported.Methods. A 63 year old lady with a traumatic C1 ring and C2 peg fracture underwent C1-C2 fixation. During insertion of the C1 lateral mass screws there was significant hemorrhage from the C1/C2 venous plexus. Three days post-operatively she developed headache, confusion and became drowsy.

Results.

CT brain revealed hydrocephalus and intraventricular blood that was managed with an external ventricular drain.

Conclusion.

The case of acute hydrocephalus due to intraventricular hemorrhage from C1 lateral mass screw placement has not previously been reported. Surgeons performing the procedure should consider the diagnosis if patients display signs of raised intracranial pressure post-operatively.