Novel use of robotics and navigation for anterior lumbar total disc replacement surgery.

The ability to navigate the anterior lumbar disc space may improve clinical outcomes and implant longevity. However, no robotic navigation systems are presently authorized by the U.S. Food and Drug Administration to assist with anterior retroperitoneal lumbar interbody surgery. Furthermore, no studies to date have investigated such an application of this technology. This study examines the application of robotic navigation to anterior lumbar total disc replacement surgery to improve retroperitoneal exposure and orientation of the anterior lumbar spine, enhance coronal plane centralization of the implant, optimize surgical trajectory, and mitigate radiologic exposure. Postoperative outcomes of a small cohort of patients undergoing anterior lumbar total disc replacement surgery using robotic navigation were analyzed. The results of the study revealed that a modified use of the aforementioned robot-assisted surgical technology enhances coronal plane centralization and trajectory, all while mitigating radiologic exposure, resulting in more accurate placement of the implant within the intervertebral space at each level.

Outpatient Versus Inpatient Anterior Lumbar Spine Surgery: A Multisite, Comparative Analysis of Patient Safety Measures.

BACKGROUND: The frequency and complexity of spinal surgery performed in an ambulatory surgery center (ASC) is increasing. However, safety and efficacy data of most spinal procedures adapted to the ASC are sparse and have focused on anterior cervical surgery. The purpose of this study was to compare the 90-day complication and readmission rates of anterior lumbar spine surgery performed in an ASC or inpatient setting. METHODS: We performed a retrospective comparative analysis of 226 consecutive anterior lumbar surgeries (283 levels treated) completed in an ASC (n = 124) or in an inpatient tertiary care hospital (n = 102) over a 3-year period. These included anterior lumbar interbody fusion (ALIF), artificial disc replacement (ADR), and hybrids. Patients undergoing simultaneous or staged posterior procedures within 3 months were excluded. Patient demographics and surgical parameters between the two surgical settings were compared. Ninety-day medical complications and readmission rates were assessed. One-way analysis of variance and Chi-square analysis were used. A P value of less than .05 was considered statistically significant. RESULTS: The two study groups had similar baseline characteristics. While there was a trend toward fewer complications, reoperations, and readmissions for the ASC cohort, the differences were not statistically significant. There were 7 intraoperative complications (5.6% minor vascular injury) in the inpatient cohort and 0 in the ASC cohort. The overall 90-day postoperative complication rate was 5.6% for the inpatient cohort and 0.9% for the ASC cohort. The 90-day readmission rate was 1.9% in the ASC cohort and 1.6% in the inpatient cohort. The 90-day reoperation rate was 0.8% for the inpatient cohort and 0% in the ASC cohort. The average hospital stay was 2.3 ± 1.5 days for the inpatient cohort. CONCLUSION: The 90-day readmission rates were lower for outpatients than for inpatients, while the complication and reoperation rates were similar. Our results demonstrate that anterior lumbar procedures, including single-level and multilevel ALIF, ADR, and hybrid procedures, can be performed safely in an ASC. This has significant cost savings implications for the ASC setting.

Thoracic cord herniation through a dural defect: description of a case and review of the literature.

BACKGROUND: Spinal cord herniation through a dural defect is a cause of myelopathy and BSS that may be underdiagnosed. It may occur spontaneously, after trauma, or after surgery. CASE DESCRIPTION: We present the case of a 47-year-old woman who presented with low back pain, progressive myelopathy, right proximal LEW, several episodes of falling, sensory changes below the lower part of the chest wall, and pathologic reflexes. Magnetic resonance imaging of the thoracic spine showed kinking of the spinal cord anteriorly at the level of T6-7. Posterior laminoplasty and intradural exploration revealed an anteriorly displaced spinal cord that was herniating through a ventral dural fold. The defect was repaired, and the spinal cord abnormality was reduced. Postoperatively, the patient's strength, gait, and sensation improved immediately. CONCLUSIONS: We discuss the successful surgical treatment of a thoracic spinal cord tethering from herniation through a ventral dural defect and review the literature regarding the proposed pathogenesis, surgical repair options, and reported outcomes.

Determination of Whole-Body and Lens Dose Conversion Factors for Japanese Field Mice, Apodemus Speciosus.

The 11 March 2011 Fukushima nuclear accident in Japan resulted in widespread radioactive contamination within the 20 km evacuation zone. Japanese field mice (Apodemus speciosus) living within the contaminated region received radiation doses from external environmental contamination as well as internally deposited radionuclides. Cataract formation in the lens of eyes of these mice is a possible deterministic effect of ionizing radiation; however, determination of actual doses is difficult. Since no dose conversion factors currently exist for the lens of the eyes of Japanese field mice, lens dose conversion factors were created using a Monte Carlo N-Particle simulation and compared to the International Commission on Radiological Protection Publication 108 reference rat whole-body dose conversion factors. Monte Carlo N-Particle simulations included doses to the lens of the eyes from external sources (received while both above and below ground), as well as doses from internal contamination. Although the Publication 108 reference rat is almost twice the average mass of the Japanese field mouse, all dose conversion factor calculations using Monte Carlo N-Particle methods were within approximately 37% of the Publication 108 values for the reference rat.

Complications of the spine in ankylosing spondylitis with a focus on deformity correction.

Ankylosing spondylitis (AS) is a systemic inflammatory disorder with frequent spinal axis symptoms. In this paper, the authors explored the spinal manifestations of AS and its characteristic anatomical lesions, radiological findings, and complications. They also offer a comprehensive report of the medical and surgical treatments with a focus on deformity correction.

Adverse swelling associated with use of rh-BMP-2 in anterior cervical discectomy and fusion: a case study.

BACKGROUND CONTEXT: The use of recombinant bone morphogenetic protein-2 (rh-BMP-2) is effective in augmenting lumbar spinal fusions. A safe, effective dosage of rh-BMP-2 in the cervical spine has yet to be determined. Use of rh-BMP-2 is currently being evaluated and is only indicated for use in the cervical spine on Investigational Device Exempt cases. PURPOSE: To present a potentially serious adverse event that may occur when using rh-BMP-2 in cervical spine surgery. STUDY DESIGN: An emergent sequence of events including physical examination, radiographic studies, intubation, and surgical exploration were performed upon arrival to the emergency department. METHODS: We report a case of a 54-year-old male patient presenting with neck swelling and difficulty swallowing 5 days after anterior cervical discectomy and fusion (ACDF) using rh-BMP-2. RESULTS: The patient was found to have massive neck swelling including the pharyngeal tissue. The patient was admitted to the intensive care unit where parenteral steroids were administered for 24 hours during monitored intubation. The patient was extubated on the second hospital day and discharged home on the fourth hospital day after swelling subsided. CONCLUSIONS: Caution should be exercised with rh-BMP-2 use in ACDF surgery as the correct dose and technique for application is not yet determined. Respiratory distress and dysphagia may result secondary to rh-BMP-2 induced anterior neck swelling.

Use of the video telescope operating monitor (VITOM) as an alternative to the operating microscope in spine surgery.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To evaluate the efficacy of video telescope operating monitor (VITOM) as an alternative to operative microscope (OM) in spinal surgery. SUMMARY OF BACKGROUND DATA: The surgical operating microscope can be expensive, cumbersome, and ergonomically disadvantageous. VITOM is a novel telescope-based exoscope system that can be used as an alternative or supplement to OM. METHODS: Patients undergoing spinal surgery were enrolled in a prospective cohort study between December 2008 and March 2011. Age, sex, and operation-matched patients undergoing surgery using the standard OM served as the control group. During surgery, the VITOM system was used in place of the OM in 24 patients. Operative time, length of postoperative hospital stay, and intraoperative complications were assessed. RESULTS.: A total of 48 patients were studied in 2 equal cohorts of 24 patients each. Within each cohort, patients underwent single-level (n = 4) and 2-level (n = 7) posterior decompression as well as single-level (n = 11) and 2-level (n = 2) transforaminal lumbar interbody fusions via VITOM, with an equal number of controls using OM. There were no significant differences in age (P = 0.79) or sex (P = 0.77) between cohorts.There were no statistically significant differences in mean operative room time for single-level decompressions (P = 0.38), 2-level decompressions (P = 0.12), single-level transforaminal lumbar interbody fusions (P = 0.13), or 2-level transforaminal lumbar interbody fusions (P = 0.15). Postoperative hospital length of stay averaged 2.9 days for the VITOM group versus 2.8 days for the traditional OM group (P = 0.75). There were no intraoperative complications in either group. Subjectively, surgeons rated the image quality as very high and equal to the OM. CONCLUSION: The VITOM system for spinal surgery provides outstanding image quality and an ease of manipulation rivaling the OM. There were no statistically significant differences in mean operative room time, intraoperative complications, or total hospital length of stay when using this novel system in several common spinal procedures relative to the OM.

Cantilever TLIF with structural allograft and RhBMP2 for correction and maintenance of segmental sagittal lordosis: long-term clinical, radiographic, and functional outcome.

STUDY DESIGN/SETTING: Prospective cohort study in a tertiary care spine center. OBJECTIVE: The effectiveness of the cantilever transforaminal lumbar interbody fusion (C-TLIF) technique in creating and maintaining lordosis, avoiding nerve problems, and obtaining fusion was studied. SUMMARY OF BACKGROUND DATA: C-TLIF is a microscope-assisted transforaminal lumbar interbody fusion technique, emphasizing no dural retraction with placement of structural allograft and RhBMP2 anteriorly under the cortical apophyseal ring, followed by middle column cancellous autograft placed under compression with posterior pedicle spinal instrumentation. METHODS: A total of 100 consecutive patients studied with an average of 30 months of follow-up. A total of 48 had prior surgery at the index level; 16 had the procedure done at an adjacent level to a previous fusion; 32 at L5-S1 with 42 at L4-L5 and 26 at L3-L4. There were 76 single-level and 24 two-level fusions. One patient was a smoker with one other patient a compensation case. Outcome was prospectively documented with self-administered Visual Analog Pain Scale, Oswestry Disability Questionnaire, Treatment Intensity Questionnaire, and SF-36 Health Survey. Patients rated the surgery as excellent, good, fair, or poor and whether they would recommend the surgery. Student t test was used for statistical analysis with significance set at P = 0.05. RESULTS: Blood loss and hospital stay averaged 300 mL and 2.2 days, respectively. There was significant reduction (P < 0.05) in pain scores from 9 to 3, Oswestry Disability Index scores from 35 to 12, and Treatment Intensity Score from 21/25 to 2/25 at final follow-up. The SF-36 PCS and MCS scores showed an increasing trend to improvement. A total of 69 rated the surgery as excellent, 23 good, 7 fair, and 1 poor. A total of 97% were satisfied and would recommend the surgery. All had improvement in radicular pain with no dural tears, neural injury, or neuropathic pain. There was significant improvement (P < 0.05) in segmental sagittal lordosis from 2 degrees to 9 degrees, anterior disc height from 6 to 14 mm, and posterior disc height from 4 to 8 mm. There was no subsidence, misplaced screws, or instrumentation failure. Solid fusion was obtained in 99 of 100 patients. CONCLUSIONS: The C-TLIF allows for creation and maintenance of sagittal lordosis while avoiding subsidence and neurologic problems with a 99% fusion rate and 97% patient satisfaction.