Umesh Metkar

The Effect of Platelet-Rich Plasma and Bone Marrow on Murine Posterolateral Lumbar Spine Arthrodesis with Bone Morphogenetic Protein

BACKGROUND Recombinant human bone morphogenetic protein-2 (rhBMP-2) has had limited success in stimulating osteogenesis at the site of posterolateral lumbar spine arthrodesis when used at the currently approved human dose for anterior lumbar interbody arthrodesis. The objective of the present study was to investigate the effect of co-administration of fresh harvested autologous bone marrow aspirate and platelet-rich plasma on rhBMP-2-mediated in vivo murine posterolateral lumbar spine arthrodesis. METHODS Forty adult male mice underwent posterolateral intertransverse process arthrodesis from L4 to L6. In three experimental groups, a collagen sponge was placed on each side, overlaying the decorticated transverse processes. Each collagen sponge was presoaked for fifteen minutes with 31 microg of rhBMP-2 in a 100-microL solution containing either saline solution (n = 10), platelet-rich plasma (n = 10), or donor bone-marrow cells (n = 10). Control mice underwent decortication alone (n = 10). The lumbar spine was harvested four weeks after surgery, and spinal fusion was evaluated on the basis of radiographs, computed tomography, and histological analysis. RESULTS Control mice showed no evidence of spinal fusion. The rate of fusion was radiographically and histologically similar in all three experimental groups. The area, volume, and density of the fusion mass were significantly greater (p < 0.05) for the group treated with rhBMP-2 and bone marrow as compared with the group treated with rhBMP-2 alone. The group treated with rhBMP-2 and platelet-rich plasma had intermediate fusion area and density. Histologically, the spines treated with rhBMP-2 alone consistently showed the presence of cortical bone between the two transverse processes but fewer trabeculae within the fusion mass; bone marrow co-augmentation resulted in more trabeculae within the fusion mass and a thicker cortical perimeter. CONCLUSIONS The present study quantitatively confirmed a synergistic effect of bone marrow cells when added to rhBMP-2 in an in vivo mouse posterolateral lumbar spine fusion model. The volume, area, and density of the fusion mass were significantly increased by augmentation with bone marrow cells.

Vertebral artery injury associated with blunt cervical spine trauma: a multivariate regression analysis.

Study Design. Retrospective analysis of prospective registry data. Objective. To determine the patient characteristics, risk factors, and fracture patterns associated with vertebral artery injury (VAI) in patients with blunt cervical spine injury. Summary of Background Data. VAI associated with cervical spine trauma has the potential for catastrophical clinical sequelae. The patterns of cervical spine injury and patient characteristics associated with VAI remain to be determined. Methods. A retrospective review of prospectively collected data from the American College of Surgeons trauma registries at 3 level-1 trauma centers identified all patients with a cervical spine injury on multidetector computed tomographic scan during a 3-year period (January 1, 2007, to January 1, 2010). Fracture pattern and patient characteristics were recorded. Logistic multivariate regression analysis of independent predictors for VAI and subgroup analysis of neurological events related to VAI was performed. Results. Twenty-one percent of 1204 patients with cervical injuries (n = 253) underwent screening for VAI by multidetector computed tomography angiogram. VAI was diagnosed in 17% (42 of 253), unilateral in 15% (38 of 253), and bilateral in 1.6% (4 of 253) and was associated with a lower Glasgow coma scale (P < 0.001), a higher injury severity score (P < 0.01), and a higher mortality (P < 0.001). VAI was associated with ankylosing spondylitis/diffuse idiopathic skeletal hyperosteosis (crude odds ratio [OR] = 8.04; 95% confidence interval [CI], 1.30–49.68; P= 0.034), and occipitocervical dissociation (P < 0.001) by univariate analysis and fracture displacement into the transverse foramen 1 mm or more (adjusted OR = 3.29; 95% CI, 1.15–9.41; P= 0.026), and basilar skull fracture (adjusted OR = 4.25; 95% CI, 1.25–14.47; P= 0.021), by multivariate regression model. Subgroup analyses of neurological events secondary to VAI occurred in 14% (6 of 42) and the stroke-related mortality rate was 4.8% (2 of 42). Neurological events were associated with male sex (P= 0.024), facet subluxation/dislocation (crude OR = 9.00; 95% CI, 1.51–53.74; P= 0.004) and the diagnosis of ankylosing spondylitis/diffuse idiopathic skeletal hyperosteosis (OR = 40.67; 95% CI, 5.27–313.96; P < 0.001). Conclusion. VAI associated with blunt cervical spine injury is a marker for more severely injured patients. High-risk patients with basilar skull fractures, occipitocervical dissociation, fracture displacement into the transverse foramen more than 1 mm, ankylosing spondylitis/diffuse idiopathic skeletal hyperosteosis, and facet subluxation/dislocation deserve focused consideration for VAI screening. Level of Evidence: 2

Femoroacetabular impingement in adolescents and young adults.

Femoroacetabular impingement (FAI) is a recently described hip disorder resulting from an abnormal morphology between the proximal femur and acetabulum (socket). It is now recognized as a cause of hip pain in adolescents and young adults, and research has shown that it may also lead to early degenerative changes and osteoarthritis. Femoroacetabular impingement as a cause of precocious hip arthrosis was originally described by Ganz et al. in 2001, and a quick literature search on this topic will confirm that it has become a topic of cutting edge research within the orthopaedic community. The abnormal morphology in FAI results in increased hip contact forces with hip motion, especially flexion. This results in abnormal contact that can lead to acetabular labral tears and cartilaginous injury. Early diagnosis and treatment may possibly delay the future onset of hip arthritis. Although the precise cause of FAI is not well understood, the condition has become increasingly recognized as a cause of hip pain in active adolescents and young adults. The purpose of this article is to outline the history, physical examination and radiographic findings, and current conservative and surgical treatment modalities for FAI.

Posterior atlantoaxial dislocation without odontoid fracture.

We report a case of posterior atlantoaxial dislocation without a fracture of the odontoid in a 35-year-old woman. There have been nine reported cases of similar injury in the English literature. The integrity of the transverse ligament following posterior atlantoaxial dislocations has not been well documented in these reports. In the present case, MRI revealed an intact transverse ligament, which probably contributed to the stability of the C1–C2 complex following closed reduction.

Giant cell tumor of a lumbar vertebra in a 7-year-old child: a case report.

Study Design: This case provides a rare occurrence of a giant cell tumor (GCT) in posterior elements of a lumbar vertebra in a 7-year-old child with successful outcome after surgical excision and regular follow-ups. Objective: To present a unique case report of a pediatric GCT in the vertebral column and results. Summary of Background Data: GCT is a rare bone tumor seen in 3% to 5% of primary bone neoplasm. Approximately 7% of GCTs are found in the vertebral column. GCT of the spine is found in only 5% to 7% of cases and can occur in any region of the spine but are believed to be predominantly in the sacrum. Despite its benign nature, expansion in a confined space makes early detection of spinal GCTs important to prevent occurrence of compressive myelopathy/radiculopathy. The presence of a GCT in a child younger than 10 years of age, in posterior elements of a lumbar vertebral body, has not been reported earlier. Methods: On the basis of the clinical history, radiograph of the thoracolumbar spine, computed tomography of lumbar spine, and magnetic resonance imaging, a preliminary diagnosis of osteoblastoma was made. Results: The patient presented with a lytic lesion with involvement of posterior elements, 1 side the pedicle extending into the body of a lumbar vertebra (L3) and had extension into the paraspinal muscles. Intraoperative exploration and frozen section showed the presence of a typical histologic picture of a GCT. Ipsilateral pedicle, posterior elements, and the superior articular facet were excised. En bloc resection was found not to be feasible due to the friable nature of the tumor and involvement of the soft tissues. In addition, fusion was avoided with consideration of the young age of the patient. Conclusions: The patient has been free of any recurrence as of his last follow-up visit.

Bioabsorbable anterior cervical plate fixation for single-level degenerative disorders: early clinical and radiographic experience

BACKGROUND CONTEXT Increased fusion rates have been reported with the addition of an anterior cervical plate (ACP) to anterior cervical discectomy and fusion (ACDF). Bioabsorbable implants have become increasingly used in orthopedic and spine surgical procedures. There are limited data regarding the outcomes of bioabsorbable ACP (bACP) with ACDF. PURPOSE To compare the clinical and radiographic outcomes of patients undergoing ACDF for single-level degenerative disorders with a bACP versus a conventional metal ACP (mACP). STUDY DESIGN Retrospective comparative cohort study. PATIENT SAMPLE Thirty-one patients undergoing ACDF for a single-level degenerative disorder (ie, disc herniation or spondylotic neural compression). OUTCOME MEASURES Incidence of early (within 2 weeks) complications, postoperative sagittal alignment, Odoms criteria, and pseudarthrosis rate. METHODS The authors retrospectively reviewed the results of a consecutive series of patients undergoing ACDF for symptomatic single-level disc herniation or spondylotic neural compression with either a bACP or an mACP over a 3-year period. Operative notes, clinical charts, and radiographs were analyzed. Radiographic outcomes were assessed for intersegmental alignment, graft subsidence, fusion rate, prevertebral soft-tissue shadow, and graft containment. Clinical outcome was evaluated by Odoms criteria. RESULTS Fourteen patients underwent ACDF with a bACP and 15 with an mACP. Radiographic outcomes at the most recent follow-up demonstrated pseudarthrosis in 4 of 14 patients (29%) in the bACP group and 0 of 15 patients in the mACP group. Graft extrusion and anterior displacement was present in three of four pseudarthroses (75%). Comparing preoperative and final radiographs, cervical lordosis was maintained at the operative segment in only 3 of 14 bACP patients (21%) compared with 8 of 15 patients (53%) in the mACP group. The mean Cobb angle was 2.4°±1.9° lordosis in the mACP group and -2.7°±2.5° kyphosis in the bACP group (p=.12). In the mACP group, 14 of 15 patients had good or excellent results. In the bACP group, only 7 of 14 patients had good or excellent results. CONCLUSIONS Bioabsorbable ACP fixation was associated with a high rate of graft extrusion and early loss of intersegmental cervical alignment. Inferior clinical outcomes were observed in patients in the bACP group compared with the mACP group. Based on these findings, continued use of the bACP used in this study cannot be recommended.

Location of the transverse foramen in the subaxial cervical spine in a young asymptomatic population.

Study Design. Computerized tomography of the subaxial cervical spine in 98 young, asymptomatic North American volunteers. Objective. To provide normative data on subaxial transverse foramen dimensions and location in relation to surgical landmarks routinely used during operative intervention in the anterior cervical spine. Summary of Background Data. Vertebral artery injury during anterior cervical spinal surgery is a rare but potentially catastrophic injury. There have been no prior studies in a large group of young, asymptomatic subjects without pathology and where the age, weight, and gender are known. There are no published computerized tomography data evaluating distances between the tip of the uncovertebral joint and the medial margin of the uncovertebral joint, 2 commonly used surgical landmarks. Methods. Axial and reconstructed coronal computerized tomography images of cervical vertebrae from C3 to C7 in 98 asymptomatic young volunteers were analyzed to measure interforaminal distance, transverse foramen distance from anterior and posterior vertebral body margins, transverse foramen dimensions, and transverse foramen medial margin distance from the uncus tip and medial margin. Results. All measurements were significantly different between males and females, with smaller female dimensions. Interforaminal distance gradually increased from C3 to C7. Transverse foramen anterior margin in relation to the anterior vertebral body was significantly more posterior at C7 compared with the C3–C6 levels. Transverse foramen posterior margin in relation to the vertebral body posterior margin gradually moved anteriorly from C3 to C6 and then posterior again at C7. The vertebral uncus tip and medial margin in relation to the medial transverse foramen averaged 2.8 mm and 5.7 mm for males and 2.7 mm and 5.3 mm for females from C3 to C6. Conclusion. Useful morphometric data are provided that may assist the operating surgeon to avoid vertebral artery injury during anterior surgical approaches to the cervical spine. The medial margin of the uncovertebral joint may be the safest landmark to avoid vertebral artery injury during anterior cervical disc surgery. The vertebral artery is at increased risk of injury during neural decompression at more cephalad levels.

Epidural varix at the cervicothoracic junction: unusual cause of quadriplegia: a case report.

Study Design. A case report describing an unusual incident of quadriplegia in a young adult male caused by an epidural varix at the cervicothoracic junction. Objective. To report an unusual case of quadriplegia caused by an epidural varix at the cervicothoracic junction. Summary of Background Data. Epidural varices are dilated tortuous elongated veins inside the central canal. In degenerative spinal stenosis, these varices are a result of venous stagnation and contribute to the pathogenesis of radicular pain. In the absence of stenosis, primary varicosities develop as a result of dynamic obstruction to venous outflow during spinal movements. A primary epidural varix can produce neurologic deficit similar to a space occupying lesion within the spinal canal. The myeloradiculopathy is of a slow progressive nature. Material and Methods. A young man presented with an acute onset flaccid quadriplegia in the absence of significant trauma. Magnetic resonance imaging revealed an extradural space occupying lesion at the cervicothoracic junction that was diagnosed as an isolated epidural varix during surgery. Results. No neurologic recovery occurred. Postoperative magnetic resonance imaging revealed a syrinx in the cervicothoracic cord. Conclusion. In the absence of other precipitating factors, the cord injury was attributed to the epidural varix. A temporary impedance to the venous outflow with the increase in the venous pressure has been hypothesized as the mechanism of cord injury.

The Effect of Kyphoplasty on Mortality in Symptomatic Vertebral Compression Fractures: A Review

ABSTRACT Background: Vertebral compression fractures (VCFs) are common comorbidities encountered in the elderly, and they are on the rise. Kyphoplasty may be superior in VCF management compared with conservative management. A comprehensive review of literature was conducted, focusing on the effect of kyphoplasty on mortality and overall survivorship in patients with a diagnosis of symptomatic VCFs. Methods: A comprehensive literature search was conducted to find recently published literature on kyphoplasty effects on mortality using the following keywords: “kyphoplasty,” “mortality,” “morbidity,” “vertebral compression fractures,” and “survivorship.” We only included articles that listed one of their primary or secondary outcomes as morbidity and mortality after a kyphoplasty procedure in VCF patients. Results: Of 27 articles, only 6 articles met the inclusion criteria. Studies have reported that surgical procedures have decreased the mortality rate in symptomatic VCF patients. Four studies concluded that the mortality rate was lower after kyphoplasty compared with vertebroplasty and nonoperative treatments. One study reported there was no significant difference between kyphoplasty and nonoperative management. One study summarized that the mortality rate was not significantly different between kyphoplasty and vertebroplasty. Conclusions: Multicenter prospective and randomized control studies are required to fully evaluate the decreasing trend of mortality rates after a kyphoplasty procedure.

Assessment of Coronal Spinal Alignment for Adult Spine Deformity Cases After Intraoperative T Square Shaped Use

STUDY DESIGN Retrospectively reviewed surgeries between 2011 and 2015 of patients who underwent posterior spinal deformity instrumentation with constructs involving fusions to pelvis and encompassing at least five levels. OBJECTIVE Measure the radiographic outcomes of coronal malalignment (CM) after use of an intraoperative T square shaped instrument in posterior spinal deformity surgeries with at least five levels of fusion and extension to pelvis. BACKGROUND Neuromuscular children found to benefit from intraoperative T square technique to help achieve proper coronal spinal balance with extensive fusions. This intraoperative technique used in our posterior spine deformity instrumentation surgeries with the aforementioned parameters. METHODS There were 50 patients: n = 16 with intraoperative T square and n = 34 no-T square shaped device. Subgroups divided based on greater than 20 mm displacement and greater than 40 mm displacement of the C7 plumb line to the central sacral vertical line on either side in preoperative radiographs. We analyzed the demographics and the pre- and postoperative radiographic parameters of standing films: standing CM (displacement of C7 plumb line to central sacral vertical line), and major coronal Cobb angles in total sample and subgroups and compared T square shaped device with no-T square shaped device use by analysis of variance. A p value ≤.05 is statistically significant. RESULTS In the total sample, though postoperative CM mean was not statistically different, we observed greater CM corrections in patients where a T square shaped device was used (70%) versus no-T square shaped device used (18%). In >20 mm and >40 mm subgroups, the postoperative mean CM values were statistically lower for the patients where a T square shaped device was used, p = .016 and p = .003, respectively. Cobb corrections were statistically higher for T square shaped device use in both >20 mm and >40 mm subgroups, 68%, respectively. CONCLUSION The intraoperative T square shaped device technique had a positive effect on the amount of spine coronal malalignment correction after its use and for lumbar and thoracic coronal Cobb angles. LEVEL OF EVIDENCE Level III.STUDY DESIGN Retrospectively reviewed surgeries between 2011 and 2015 of patients who underwent posterior spinal deformity instrumentation with constructs involving fusions to pelvis and encompassing at least five levels. OBJECTIVE Measure the radiographic outcomes of coronal malalignment (CM) after use of an intraoperative T square shaped instrument in posterior spinal deformity surgeries with at least five levels of fusion and extension to pelvis. BACKGROUND Neuromuscular children found to benefit from intraoperative T square technique to help achieve proper coronal spinal balance with extensive fusions. This intraoperative technique used in our posterior spine deformity instrumentation surgeries with the aforementioned parameters. METHODS There were 50 patients: n = 16 with intraoperative T square and n = 34 no-T square shaped device. Subgroups divided based on greater than 20 mm displacement and greater than 40 mm displacement of the C7 plumb line to the central sacral vertical line on either side in preoperative radiographs. We analyzed the demographics and the pre- and postoperative radiographic parameters of standing films: standing CM (displacement of C7 plumb line to central sacral vertical line), and major coronal Cobb angles in total sample and subgroups and compared T square shaped device with no-T square shaped device use by analysis of variance. A p value ≤.05 is statistically significant. RESULTS In the total sample, though postoperative CM mean was not statistically different, we observed greater CM corrections in patients where a T square shaped device was used (70%) versus no-T square shaped device used (18%). In >20 mm and >40 mm subgroups, the postoperative mean CM values were statistically lower for the patients where a T square shaped device was used, p = .016 and p = .003, respectively. Cobb corrections were statistically higher for T square shaped device use in both >20 mm and >40 mm subgroups, 68%, respectively. CONCLUSION The intraoperative T square shaped device technique had a positive effect on the amount of spine coronal malalignment correction after its use and for lumbar and thoracic coronal Cobb angles. LEVEL OF EVIDENCE Level III.