Metal-Free Cortico-Pedicular Device for Supplemental Fixation in Lumbar Interbody Fusion.

OBJECTIVE: Pedicle screw fixation is a commonly utilized adjunct for lumbar interbody fusion, yet risks include screw malposition, pullout, loosening, neurovascular injury, and stress transfers leading to adjacent segment degeneration. This report describes the preclinical and initial clinical results of a minimally invasive, metal-free cortico-pedicular fixation device used for supplemental posterior fixation in lumbar interbody fusion. METHODS: Safety of arcuate tunnel creation was evaluated in cadaveric lumbar (L1-S1) specimens. A finite element analysis study evaluated clinical stability of the device to pedicular screw-rod fixation at L4-L5. Preliminary clinical results were assessed by analysis of Manufacturer and User Facility Device Experience database complications, and 6-month outcomes in 13 patients treated with the device. RESULTS: Among 35 curved drill holes in 5 lumbar specimens, no breaches of the anterior cortex were identified. The mean minimum distance from the anterior surface of the hole to the spinal canal ranged from 5.1 mm at L1-L2 to 9.8 mm at L5-S1. In the finite element analysis study, the polyetheretherketone strap provided comparable clinical stability and reduced anterior stress shielding compared to the conventional screw-rod construct. The Manufacturer and User Facility Device Experience database identified 1 device fracture with no clinical sequelae among 227 procedures. Initial clinical experience showed a 53% decrease in pain severity (P = 0.009), a 50% decrease in Oswestry Disability Index (P < 0.001), and no device-related complications. CONCLUSIONS: Cortico-pedicular fixation is a safe and reproducible procedure that may address limitations of pedicle screw fixation. Longer term clinical data in large clinical studies are recommended to confirm these promising early results.

Decreased incidence of venous thromboembolism after spine surgery with early multimodal prophylaxis: Clinical article.

OBJECT: Venous thromboembolism (VTE) represents a significant complication after spine surgery, with reported rates as high as 2%-4%. Published institutional practices for VTE prophylaxis are highly variable. In 2008, the authors implemented a departmental protocol for early VTE prophylaxis consisting of combined compressive devices and subcutaneous heparin initiated either preoperatively or on the same day of surgery. In this study, the authors compared the incidence of VTE in spine surgery patients before and after implementing this protocol. METHODS: An institutional review board-approved retrospective review of outcomes in patients undergoing spine surgery 2 years before protocol implementation (representing the preprotocol group) and of outcomes in patients treated 2 years thereafter (the postprotocol group) was conducted. Inclusion criteria were that patients were 18 years or older and had been admitted for 1 or more days. Before 2008 (preprotocol), VTE prophylaxis was variable and provider dependent without any uniform protocol. Since 2008 (postprotocol), a new VTE-prophylaxis protocol was administered, starting either preoperatively or on the same day of surgery and continuing throughout hospitalization. The new protocol consisted of 5000 U heparin administered subcutaneously 3 times daily, except in patients older than 75 years or weighing less than 50 kg, who received this dose twice daily. All patients also received sequential compression devices (SCDs). The incidence of VTE in the 2 protocol phases was identified by codes of the International Classification of Diseases, Ninth Revision (ICD-9) codes for deep vein thrombosis (DVT) and pulmonary embolus (PE). Bleeding complications arising from anticoagulation treatments were evaluated by the Current Procedural Terminology (CPT) code for postoperative epidural hematoma (EDH) requiring evacuation. RESULTS: In total, 941 patients in the preprotocol group met the inclusion criteria: 25 had DVT (2.7%), 6 had PE (0.6%), and 6 had postoperative EDH (0.6%). In the postprotocol group, 992 patients met the criteria: 10 had DVT (1.0%), 5 had PE (0.5%), and 4 had postoperative EDH (0.4%). This reduction in DVT after the protocol's implementation was statistically significant (p = 0.009). Despite early aggressive prophylaxis, the incidence of postoperative EDH did not increase and compared favorably to the published literature. CONCLUSIONS: At a high-volume tertiary center, an aggressive protocol for early VTE prophylaxis after spine surgery decreases VTE incidence without increasing morbidity.

Readmissions in neurosurgery: a qualitative inquiry.

OBJECTIVE: To identify deficiencies leading to readmissions to the University of Florida Neurosurgery Service by using the Institute for Healthcare Improvement STate Action on Avoidable Rehospitalizations Readmissions diagnostic tool and to report the opinions of patients, their families, and health care providers. METHODS: A retrospective review of hospital admission and discharge data was conducted. All patients who met eligibility criteria and who were discharged from the neurosurgery service between January 1 and March 31, 2012, and readmitted within 30 days after discharge (n=74; 66 patients; 7 multiple readmissions) were included. A chart review revealed potential precipitating factors. Health care providers, patients, and family members were also interviewed. Median values and frequencies were used to summarize the data. RESULTS: The 30-day readmission rate on the neurosurgery service was 14%. Problems associated with wound care accounted for 24% of readmissions, neurologic conditions accounted for 50%, and other medical conditions accounted for 26%. Patients and providers agreed on the medical diagnoses resulting in readmission, but providers also often named "patient noncompliance" as a factor leading to readmission, whereas patients often thought they either were "sent home too early" or had a "general decline with no improvement." CONCLUSIONS: Systematic patterns and common themes associated with patient readmissions were identified for a neurosurgical service. These findings are now being used to implement changes in discharge planning.

Temporary percutaneous pedicle screw fixation for treatment of thoracolumbar injuries in young adults.

OBJECTIVE: Bone-only injuries of the spine, including Chance fractures, are commonly managed nonoperatively. However, selected patients may benefit from surgical stabilization. In this report, the authors describe a method of temporary internal fixation with percutaneous pedicle screws for patients with intractable pain and thoracolumbar fractures. METHODS: We reviewed the medical records and imaging studies of three patients 17 to 21 years old with thoracolumbar fractures that were treated with temporary internal fixation. The patients had bone-only injuries without a major deformity. Additionally, they had severe pain that was uncontrolled with parenteral pain medications and prevented mobilization with traditional external bracing. For fixation, pedicle screws were placed percutaneously in the level above and below the fracture. No arthrodesis was performed. After 6 months, fracture healing was evaluated radiographically. Once confirmed, the instrumentation was removed. Outcomes examined include length of stay, pain control, time to ambulation, and fracture healing. RESULTS: Three patients were included in the review, ages 17 to 21 (mean 18.7) years. Two patients had classic Chance fractures, and the third had bilateral pars fractures with a compression fracture at the same level. All patients had severe pain despite bracing. Postoperatively, all patients had significant pain reduction that facilitated rapid mobilization. At 6 months after surgery, fracture healing was verified with radiographic imaging and the instrumentation was removed. There were no complications. CONCLUSIONS: Temporary internal bracing of bone-only thoracolumbar fractures in young adults is a safe and effective treatment strategy in selected patients. This procedure provides rapid pain control and early mobilization without sacrificing any spinal motion segments.

Does ossification of the posterior longitudinal ligament progress after laminoplasty? Radiographic and clinical evidence of ossification of the posterior longitudinal ligament lesion growth and the risk factors for late neurologic deterioration.

Ossification of the posterior longitudinal ligament (OPLL) is a disease process characterized by progressive growth and calcification resulting in spinal canal compromise and serious neurological sequelae in advanced cases. Historically, OPLL has most commonly been treated with posterior surgical decompression. Although this procedure indirectly decompresses the spinal cord, it does not address the offending pathological entity, and further growth of the lesion may result in delayed neurological deterioration. This fact is particularly relevant because a number of long-term studies have revealed both longitudinal and transverse disease progression in individuals treated both surgically and conservatively. Despite these high rates of radiographically documented progression, however, the rate of neurological decline in patients undergoing posterior surgery with laminoplasty is low. In this article, the authors review the pathophysiology of OPLL, evidence of disease progression, and outcome data addressing conservative and surgical treatments.

Radiographic response of brain metastasis after linear accelerator radiosurgery.

BACKGROUND: Radiographic response of brain metastasis to stereotactic radiosurgery (SRS) over time has not been well characterized. Being able to predict SRS-induced changes in tumor size over time may allow improved counseling of patients and potentially earlier recognition of poor response to SRS. OBJECTIVE: To quantify the rate of change in size of metastatic brain tumors after treatment with a linear accelerator (LINAC) SRS. METHODS: We performed a retrospective analysis of patients with single metastatic brain tumors treated with LINAC SRS at the University of Florida between 1992 and 2009 who had at least one MRI after treatment. A total of 218 patients with 406 follow-up MRI scans were included in the study. Tumor area was calculated by measuring the largest tumor area on axial imaging and using the equation for area of an ellipse. Primary outcome was percent change in tumor size. The contribution of several factors including gender, primary tumor histology, synchronous or asynchronous presentation, prior treatment, primary tumor control, and SRS dose were examined using multivariate analysis. RESULTS: Mean patient age was 58.3 years (range 4-86), and 48.6% of patients were female. Sixty-three percent of patients had primary tumor control and 70.6% had asynchronous presentation of their brain metastases. SRS peripheral dose range was 1,000-2,250 cGy with a median of 1,750 cGy. The mean percent size change was -22.6% with a mean rate of change of -7.0% per month. The median percent change was -49.7% with a median rate of change of -8.8% per month. The median follow-up was 4.8 months (range 0.3-52.5). Female gender and melanoma histology were found to be significant predictors of an increase in tumor size. Lack of previous surgical resection was a significant predictor of a decrease in tumor size after SRS. Other factors tested with multivariate analysis, including age, synchronicity of presentation, dose, dose volume, Karnofsky performance score, and primary tumor control, were not significant in predicting tumor size change after SRS. CONCLUSION: In this study, brain metastases decreased in size by a median of 50% for a median follow-up of 4.8 months after SRS. The overall rate of decrease was 9% per month after treatment with SRS. Melanoma histology was a predictor of poor tumor control.

Recombinant human bone morphogenetic protein-2 as an adjunct for spine fusion in a pediatric population.

BACKGROUND/AIMS: Recombinant human bone morphogenetic protein-2 (rhBMP-2) is responsible for multiple different signaling processes including positive effects on bone formation and fusion. In 2002, rhBMP-2 was approved for use in anterior lumbar spinal fusion by the Food and Drug Administration. Since that time, rhBMP-2 use for spinal fusion has become widespread. The use of rh-BMP2 for pediatric spinal fusion, however, has not been widely reported. We report the experience of the use of rhBMP-2 for pediatric spinal fusion at the University of Florida. METHODS: Data on patients under the age of 18 years who underwent spinal fusion with rhBMP-2 as an adjunct were retrospectively collected. Of these, 17 met the inclusion criteria and were reviewed. Two patients did not have adequate postoperative imaging. Fifteen patients were included in the final review. RESULTS: All 15 patients showed osseous fusion. Complications included one CSF leak and one wound infection, one misplaced screw requiring revision, and one case of adjacent segment kyphosis requiring extension of the original construct. CONCLUSION: rhBMP-2 is a successful adjunct for fusion in pediatric patients. Many of these patients had congenital defects that historically decrease fusion rates. rhBMP-2 appears safe and has an associated high rate of osseous fusion.