Local Control in Patients with Metastatic Renal Cell Carcinoma to the Spine: The Experience of an Institution with a Multidisciplinary Spine Oncology Program.

BACKGROUND: The outcomes for patients with metastatic renal cell carcinoma (RCC) to the spine who underwent stereotactic body radiotherapy (SBRT) through a multidisciplinary spine oncology program are not well described. We sought to describe the clinical course and local control rates at 1 and 2 years for these patients. METHODS: A retrospective analysis of a prospectively maintained database of adult oncologic patients receiving SBRT to the spine through a multidisciplinary spine oncology program at a single institution from 2010 to 2021 was performed. Patients with a pathologic diagnosis of RCC were included. RESULTS: A total of 75 spinal sites were treated in 60 patients. Of the 60 patients, 75.0% were men, and the mean patient age was 59.2 ± 11.3 years. At 1 year after treatment, 6 of the 60 patients were lost to follow-up. Of the remaining 54 patients, 18 were censored by death and 7 treatment sites showed local recurrence, for 37 of 44 treatment sites with local control (87.8%). At 2 years, 1 additional local recurrence had developed, 15 patients were censored by death, and no additional patients had been lost to follow-up, resulting in 28 of 36 treatment sites with local control (83.2%). None of the patients who had undergone repeat SBRT had local recurrence at 1 or 2 years. For those with local recurrence, the average time from treatment to progression was 6.6 ± 6.5 months. CONCLUSIONS: In this cohort, one of the largest reported studies of spine SBRT for metastatic RCC, local control was high at 1 and 2 years. Our findings support the role of coordinated, algorithmic treatment for these patients.

Lateral mass screw placement in the atlas: description of a novel surgical technique, radiographic parameters, and review of the literature.

BACKGROUND: Numerous techniques of C1 lateral mass screw placement have been described. We sought to delineate the radiographic angle of safety medially and laterally and describe a novel surgical technique of C1 lateral mass screw placement. We sought to (I) determine the angle of safety medially and laterally of the C1 lateral mass; (II) assess the size available of the lateral mass in the AP and coronal planes; (III) describe novel technique of insertion of a C1 lateral mass screw utilizing navigation and a novel start point. METHODS: We retrospectively reviewed cervical computed tomography (CT) images of normal adults. Radiographic measurements were then obtained using these images including the angle (degrees) of safety medially and lateral of the C1 lateral mass bilaterally, as well as the length and width (mm) of the C1 lateral masses. A novel surgical technique was used by identifying the confluence of the medial aspect of the posterior arch and the lateral mass. This confluence is then marked out as the C1 screw start point. Under navigation guidance, lateral mass screws were placed with 0 degrees of medial-lateral angulation from posterior to anterior. RESULTS: Forty-five patients with a mean age of 52.6±25.6 years (33% female) were included. The mean medial and lateral angle of safety of the C1 lateral mass bilaterally was 23±3.8 degrees and 32±5 degrees, respectively. Average length and width of the lateral mass was 17.7 and 13.3 mm respectively. CONCLUSIONS: This study describes the radiographic window of safety medially and laterally for safe and reproducible placement of C1 lateral mass screws. Further, a novel technique using a medial start point and navigation guidance with 0 degrees of angulation in the coronal plane is described. Further research is required to assess outcomes of patients utilizing this method as well as biomechanical studies to assess this construct strength compared to others that are frequently used.

Congenital defect of the posterior arch of C1: a case report.

Odontoid fractures are one of the most common injuries to the cervical spine in geriatric patients. Congenital C1 arch absence, however, is a very rare anomaly found in the population. We describe the first reported case of a congenital C1 posterior arch absence and C1 anterior cleft presenting with odontoid fracture. We present the case of a 58-year-old male who was found to have a comminuted type III odontoid fracture with significant angulation and displacement. CT scan demonstrated this fracture and also demonstrated congenital cleft of his left anterior arch and absence of left C1 posterior arch. Given his anatomic anomaly, we elected to perform occipitocervical fusion. The patient underwent occipito-cervical fusion to avoid iatrogenic vertebral artery injury. He was also immobilized in a halo vest given patient-specific social factors and compromised bone quality. The patient had no intra- or post-operative complications, but a prolonged hospital stay due to alcohol withdrawal. At 3-month postoperatively the patient had no neck pain and return to baseline function. This case highlights the importance of obtaining a CT scan preoperatively to not only to further characterize the fracture but also for surgical planning and recognition of anatomic anomalies as this may significantly impact the operative strategy.

Humeral Head Ossification Growth Prediction: Can This Method Be Reproduced?

BACKGROUND: Radiographically assessing skeletal maturity is of paramount importance to guide appropriate management for patients with adolescent idiopathic scoliosis. The reported advantages of the Humeral Head Ossification System (HHOS) are an even distribution around peak growth age (PGA), the presence of an optimal view of the humeral head in most scoliosis radiographs, and an interobserver and intraobserver reliability of 0.95 and 0.96, respectively. The goal of this study was to determine whether similar reliability could be achieved at an institution other than the one at which the HHOS was originally described. METHODS: Six raters used the HHOS to stage the humeral head on 30 deidentified posteroanterior spine radiographs. This process was repeated 2 weeks later. All raters were provided with a document demonstrating the radiographic parameters of each stage, as well as annotations to aid with classification. Intraclass coefficients were calculated. A secondary analysis was then performed grouping stages 1-2 as "pre-PGA" and 3-5 as "post-PGA." RESULTS: Fair to moderate interobserver and intraobserver reliability was achieved when determining each individual HHOS stage. This improved to good to excellent when the humeral was classified as pre-PGA or post-PGA. Subanalysis did not show any correlation between intraobserver reliability and level of orthopaedic experience. CONCLUSIONS: We found fair to moderate interobserver and intraobserver reliability with the HHOS and this was independent of level of orthopaedic experience. This is much lower than reported by the authors who developed the system, and suggests that the HHOS might not be as easy to incorporate into a scoliosis management algorithm as previously noted. The improved reliability achieved when staging the humeral head as pre-PGA or post-PGA might be the true benefit of this system. LEVEL OF EVIDENCE: Level III-diagnostic.

Analysis of the Effect of the Size and Grade of Soft Tissue Sarcoma on Rates of Unplanned Resection, Metastatic Disease, Mortality, and Morbid Re-Resection Over 20 Years.

Soft tissue sarcomas are rare malignancies that are often presumed to be benign and are resected without the typical preoperative workup, such as imaging or biopsy. These unplanned resections occur in approximately 30% of all cases and frequently require further morbid treatments, resulting in worse oncologic outcomes. A retrospective review was performed of all patients who presented to a tertiary sarcoma center with a diagnosis of sarcoma between 1996 and 2017. In-depth chart reviews were performed for the 2600 patients who were identified, with 836 having a primary diagnosis of soft tissue sarcoma in an upper or lower extremity. Data collected included histologic features, grade, size, resection status, demographic features, referral information, metastatic disease, morbid procedures, and mortality rate. Patients were divided into 2 groups based on whether the tumor size was greater or less than 5 cm. This classification was in keeping with the guideline of referring patients to a tertiary sarcoma center for workup for tumors "larger than a golf ball." The difference in the rate of unplanned resection for tumors measuring less than 5 cm (41.6%) and those measuring 5 cm or greater (18.8%) was statistically significant (P<.001), with smaller tumors more likely to undergo unplanned resection, in keeping with the success of the "golf ball rule." The rate of metastatic disease for unplanned resection for tumors measuring 5 cm or greater (50.7%) was significantly greater than that for tumors measuring less than 5 cm (19.7%) (P<.001). The authors found a great deal of morbidity associated with unplanned resection, regardless of tumor size. Before resection is planned, delineation is required beyond tumor size. [Orthopedics. 2021;44(3):166-171.].

Stereotactic navigation in anterior cervical spine surgery: surgical setup and technique.

Intraoperative stereotactic navigation in spine surgery is quickly becoming popularized for accurate placement of spinal instrumentation as well as assisting in the verification of anatomic landmarks. Navigation is less commonly utilized in anterior cervical spine surgery due to instrumentation being able to be placed under direct visualization. The utility of navigation in anterior cervical spine surgery is its ability to aid in the verification of anatomic location, particularly when anatomy is distorted or pathology comes close to critical neurovascular structures. We present a technique guide for anterior cervical spine navigation that we have applied at our institution and have found to be very beneficial in select patients, particularly those with complex anatomy, large body mass index, undergoing revision surgery, sustained spinal trauma and those patients with severe anterior ossification where depth or medial-lateral landmarks are difficult to visualize. We describe utilization of the technique using a case examples and specifically in a patient with significant ossification of the posterior longitudinal ligament and severe spinal cord compression that underwent multilevel cervical corpectomy. The described technique was found to be reproducible and effective, allowing cervical spine surgeons to perform more complex or minimally invasive procedures with safety and accuracy. We emphasize that navigation does not replace knowledge of anatomy or technical aspects of the procedure.

Surgical correction of rigid cervicothoracic deformity in a transgender patient: case report.

A number of spinal pathologies result in fusion of the spine, including ankylosing spondylitis, diffuse idiopathic skeletal hyperostosis (DISH), as well as severe degenerative arthropathies. This fusion of spinal elements may result in spinal deformity affecting any region of the spine. Cervicothoracic deformity resulting in chin on chest deformity is poorly tolerated due to inability to maintain a horizontal gaze. Surgical treatment options for this condition are complex and require extensive discussion between the patient and surgical team. Here we present a case report of a 26-year-old transgender female (male to female) patient with severe chin on chest deformity and a unique pattern of spinal fusion involving only the posterior elements. She underwent C2-T8 posterior spinal fusion with thoracic pedicle subtraction osteotomy and multiple cervical facet osteotomies with good functional result. She did have severe dysphagia and required feeding tube for several weeks but did very well by 1 year postoperatively. While posterior elements of the spine are normally affected first in spondyloarthropathies such as ankylosing spondylitis, the lack of anterior spinal involvement is unique and could be attributed to hormonal therapy in this patient. This case describes a unique pattern of spondyloarthropathy and highlights the importance of a having a multi-disciplinary team for the treatment of patients with complex spinal pathologies.

Spondylolysis and spondylolisthesis: A review of the literature.

Spondylolysis is a common diagnosis with a high prevalence in children and adolescents complaining of low back pain. It may be caused by either a defect or fracture of the pars interarticularis due to mechanical stress. Depending on the severity of the spondylolysis and symptoms associated it may be treated either conservatively or surgically, both of which have shown significant success. Conservative treatments such as bracing and decreased activity have been shown to be most effective with patients who have early diagnosis and treatment. Low-intensity pulsed ultrasound (LIPUS) in addition to conservative treatment appears to be very promising for achieving a higher rate of bony union. LIPUS requires more supporting studies, but may prove to become a standard of care in the future. Surgery may be required if conservative treatment, for at least six months, failed to give sustained pain relief for the activities of daily living. Based on studies performed on each of the major surgical treatments we suggest the use of the pedicle screw hook technique and the pedicle screw rod technique due to low rates of hardware failure, increased maintenance of mobility, and lack of a postoperative bracing requirement.

Allogeneic Platelet Releasate Preparations Derived via a Novel Rapid Thrombin Activation Process Promote Rapid Growth and Increased BMP-2 and BMP-4 Expression in Human Adipose-Derived Stem Cells.

The administration of human adipose-derived stem cells (ASCs) represents a promising regenerative therapy for the treatment of orthopedic injuries. While ASCs can be easily isolated from liposuction-derived adipose tissue, most clinical applications will likely require in vitro culture expansion of these cells using nonxenogeneic components. In this study, platelet releasate was generated using a novel rapid thrombin activation method (tPR). ASCs grown in media supplemented with tPR proliferated much faster than ASCs grown in media supplemented with 10% fetal bovine serum. The cells also retained the ability to differentiate along chondrogenic, adipogenic, and osteogenic lineages. The tPR cultured ASCs displayed elevated expression of BMP-4 (5.7 ± 0.97-fold increase) and BMP-2 (4.7 ± 1.3-fold increase) and decreased expression of PDGF-B (4.0 ± 1.4-fold decrease) and FGF-2 (33 ± 9.0-fold decrease). No significant changes in expression were seen with TGF-ß and VEGF. This pattern of gene expression was consistent across different allogeneic tPR samples and different ASC lines. The use of allogeneic rapidly activated tPR to culture ASCs is associated with both an increased cell yield and a defined gene expression profile making it an attractive option for cell expansion prior to cell-based therapy for orthopedic applications.