Placement of C1 Pedicle Screws Using Minimal Exposure: Radiographic, Clinical, and Literature Validation.

BACKGROUND: Traditional C1-2 fixation involves placement of C1 lateral mass screws. Evolving techniques have led to the placement of C1 pedicle screws to avoid exposure of the C1-C2 joint capsule. Our minimal dissection technique utilizes anatomical landmarks with isolated exposure of C2 and the inferior posterior arch of C1. We evaluate this procedure clinically and radiographically through a technical report. METHODS: Consecutive cases of cranial-vertebral junction surgery were reviewed for one fellowship trained spinal surgeon from 2008-2014. Information regarding sex, age, indication for surgery, private or public hospital, intra-operative complications, post-operative neurological deterioration, death, and failure of fusion was extracted. Measurement of pre-operative axial and sagittal CT scans were performed for C1 pedicle width and C1 posterior arch height respectively. RESULTS: 64 patients underwent posterior cranio-vertebral junction fixation surgery. 40 of these patients underwent occipital-cervical fusion procedures. 7/9 (77.8%) C1 instrumentation cases were from trauma with the remaining two (22.2%) from oncologic lesions. The average blood loss among isolated C1-C2 fixation was 160cc. 1/9 patients (11.1%) suffered pedicle breech requiring sub-laminar wiring at the C1 level. On radiographic measurement, the average height of the C1 posterior arch was noted at 4.3mm (range 3.8mm to 5.7mm). The average width of the C1 pedicle measured at 5.3mm (range 2.8 to 8.7mm). The patient with C1 pedicle screw failure had a pedicle width of 2.78mm on pre-operative axial CT imaging. CONCLUSION: Our study directly adds to the literature with level four evidence supporting a minimal dissection of C1 arch in the placement of C1 pedicle screws with both radiographic and clinical validation. CLINICAL RELEVANCE: Justification of this technique avoids C2 nerve root manipulation or sacrifice, reduces bleeding associated with the venous plexus, and leaves the third segment of the vertebral artery unexplored. Pre-operative review of imaging is critical in the placement of C1-C2 instrumentation.

Complications of Anterior Cervical Fusion using a Low-dose Recombinant Human Bone Morphogenetic Protein-2.

OBJECTIVE: There are several reports, which documented a high incidence of complications following the use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in anterior cervical fusions (ACFs). The objective of this study is to share our experience with low-dose rhBMP-2 in anterior cervical spine. METHODS: We performed a retrospective analysis of 197 patients who underwent anterior cervical fusion (ACF) with the use of recombinant human bone morphogenetic protein-2 (rhBMP-2) during 2007-2012. A low-dose rhBMP-2 (0.7mg/level) sponge was placed exclusively within the cage. In 102 patients demineralized bone matrix (DBM) was filled around the BMP sponge. Incidence and severity of dysphagia was determined by 5 points SWAL-QOL scale. RESULTS: Two patients had prolonged hospitalization due to BMP unrelated causes. Following the discharge, 13.2%(n=26) patients developed dysphagia and 8.6%(n=17) patients complained of neck swelling. More than half of the patients (52.9%, n=9) with neck swelling also had associated dysphagia; however, only 2 of these patients necessitated readmission. Both of these patients responded well to the intravenous dexamethasone. The use of DBM did not affect the incidence and severity of complications (p>0.05). Clinico-radiological evidence of fusion was not observed in 2 patients. CONCLUSION: A low-dose rhBMP-2 in ACFs is not without risk. However, the incidence and severity of complications seem to be lower with low-dose BMP placed exclusively inside the cage. Packing DBM putty around the BMP sponge does not affect the safety profile of rhBMP-2 in ACFs.

Impact of body habitus on fluoroscopic radiation emission during minimally invasive spine surgery.

OBJECT: Minimally invasive spine surgeries (MISSs) have gained immense popularity in the last few years. Concern about the radiation exposure has also been raised. The purpose of this study was to demonstrate the impact of body habitus on the radiation emission during various MISS procedures. The authors also aim to evaluate the effect the surgeon's experience has on the amount of radiation exposure during MISS especially with regard to patient size. METHODS: The authors conducted a retrospective analysis of 332 patients who underwent 387 MISS procedures performed at their institution from January 2010 to August 2013 by a single surgeon. The dose of radiation emission available from the fluoroscopic equipment was recorded from the electronic database. The authors analyzed mainly 3 procedure groups: microdiscectomy/decompression (MiDD, n=211) and transforaminal lumbar interbody fusion (TLIF) either with unilateral instrumentation (UnTLIF, n=106) or bilateral instrumentation (BiTLIF, n=70). The patients in each procedure group were divided into 6 categories based on the WHO criteria for obesity: underweight (body mass index [BMI]<18.50), normal (18.50-24.99), overweight (25.00-29.99), Class 1 obese (30.00-34.99), Class 2 obese (35.00- 39.99), and Class 3 obese (>40.00). RESULTS: Patients who underwent BiTLIF had the highest median radiation exposure (113 mGy, SD 9.44), whereas microdiscectomy required minimal exposure (12.62 mGy, SD 2.75 mGy). There was a significant correlation between radiation emission and BMI of the patients during all MISS procedures (p<0.05). The median radiation exposure was substantially greater with larger patients (p≤0.001). In the analyses within the procedure groups, radiation exposure was found to be significantly high in patients who were severely obese (Class 2 and Class 3 obesity). The radiation emission was lower during the surgeries performed in 2013 than during those performed in 2010 especially in obese patients; however, this observation was not statistically significant. CONCLUSIONS: Body habitus of the patients has a substantial impact on radiation emission during MISS. Severe obesity (BMI≥35) is associated with a significantly greater risk of radiation exposure compared with other weight categories. Surgical experience seems to be associated with lower radiation emission especially in cases in which patients have a higher BMI; however, further studies should be performed to examine this effect.

Spine and spinal cord trauma: diagnosis and management.

Spine trauma is a devastating clinical condition that affects many people annually on a worldwide basis. Management of spinal trauma has become much more surgically oriented with advances in stabilization techniques over the past two decades. The degree of injury to the spinal cord dictates the prognosis of the patient in cervical and thoracolumbar trauma. Traumatic spinal cord injury is a major area of socioeconomic burden and, as such, is a burgeoning area of ongoing research interest.

Metastatic prostate mass to the intradural foramen magnum region: a case report.

Intradural metastatic tumors of the foramen magnum region are extremely rare tumors. We report a 73-year-old patient that presented with right hemiparesis and a recent history of prostate biopsy for an enlarged prostate. Imaging revealed an anterolateral intradural foramen magnum mass with compression of the medulla. A right far lateral approach with condyle preservation was used to resect the mass. Pathological examination revealed the tumor as a metastatic prostate mass. The patient had a significant recovery of motor function and was given adjuvant external beam radiation. At the time of last follow-up, the patient had good clinical relief from the preoperative symptoms. To our knowledge, this is the first reported case of an intradural foramen magnum prostate tumor metastasis. We report on multimodal management of this rare, yet morbid presentation of a common tumor.

The role of flexion and extension computed tomography with reconstruction in clearing the cervical spine in trauma patients: a pilot study.

OBJECT: As a result of spinal trauma, approximately 12,000 individuals become quadriplegic or paraplegic each year in the US. The cervical spine is the most frequently injured part of the spinal column, and approximately 60% of spinal cord injuries involve the cervical region. The cervical collar remains the best method of prehospital spinal stabilization. Following trauma, difficulty securing an airway, the shielding of life-threatening injuries, and pressure ulcers are just a few of the serious problems that may be encountered in patients placed in cervical collars. The authors' goal was to develop an efficient method of clearing the cervical spine, by incorporating flexion and extension CT scanning with reconstruction (FECTR) into a trauma protocol. METHODS: This prospective study reviewed consecutive patients evaluated by the neurosurgery and trauma services who underwent FECTR. Imaging studies were reviewed using the Picture Activating and Communication System. The incidence of injury detection was recorded, and detection of otherwise-missed cervical spinal injuries using FECTR and CT scanning were also recorded. This technique was also applied, without causing any new neurological complications, for comatose patients if the original CT showed no suspicion of unstable injury. The study end point was determination of the presence of cervical spinal column injury that would pose a threat of instability or injury to the patient. RESULTS: Seventy-seven consecutive patients who underwent FECTR were identified. Far superior visualization of the cervicothoracic junction was achieved compared with flexion-extension cervical spine radiographs. In this case series, the sensitivity and specificity, respectively, of both FECTR and CT were 80% and 98.6% for all radiographic abnormalities. More importantly, for clinically unstable injuries, FECTR had a sensitivity of 100%. The use of FECTR added approximately 10-12 minutes to the time required for CT scanning. CONCLUSIONS: The authors' initial findings show FECTR to be a safe, effective, and efficient method of posttraumatic cervical spine clearance. In unconscious or obtunded patients, FECTR facilitates cervical spine clearance with a high degree of accuracy. A larger prospective study is needed to confirm these findings.

Papillary tumor of pineal region: prolonged control rate after gamma knife radiosurgery - a case report and review of literature.

Papillary tumors of the pineal region (PTPR) are very rare. We describe the first report of a PTPR empirically managed with gamma knife radiosurgery. The patient was initially shunted and referred for empirical gamma knife radiosurgery. After initially showing some improvement, he had recurrence of tumor after 7 years. For recurrence he underwent a gross total resection and the biopsy established the diagnosis of PTPR. Further research needs to be done as to the efficacy of gamma knife surgery for PTPR. In addition, the role of stereotactic biopsy for eligible patients should be considered as the initial step to direct the treatment of choice.