Robot-assisted and augmented reality-assisted spinal instrumentation: a systematic review and meta-analysis of screw accuracy and outcomes over the last decade

OBJECTIVE: The use of technology-enhanced methods in spine surgery has increased immensely over the past decade. Here, the authors present the largest systematic review and meta-analysis to date that specifically addresses patient-centered outcomes, including the risk of inaccurate screw placement and perioperative outcomes in spinal surgeries using robotic instrumentation and/or augmented reality surgical navigation (ARSN). METHODS: A systematic review of the literature in the PubMed, EMBASE, Web of Science, and Cochrane Library databases spanning the last decade (January 2011-November 2021) was performed to present all clinical studies comparing robot-assisted instrumentation and ARSN with conventional instrumentation techniques in lumbar spine surgery. The authors compared these two technologies as they relate to screw accuracy, estimated blood loss (EBL), intraoperative time, length of stay (LOS), perioperative complications, radiation dose and time, and the rate of reoperation. RESULTS: A total of 64 studies were analyzed that included 11,113 patients receiving 20,547 screws. Robot-assisted instrumentation was associated with less risk of inaccurate screw placement (p \u3c 0.0001) regardless of control arm approach (freehand, fluoroscopy guided, or navigation guided), fewer reoperations (p \u3c 0.0001), fewer perioperative complications (p \u3c 0.0001), lower EBL (p = 0.0005), decreased LOS (p \u3c 0.0001), and increased intraoperative time (p = 0.0003). ARSN was associated with decreased radiation exposure compared with robotic instrumentation (p = 0.0091) and fluoroscopy-guided (p \u3c 0.0001) techniques. CONCLUSIONS: Altogether, the pooled data suggest that technology-enhanced thoracolumbar instrumentation is advantageous for both patients and surgeons. As the technology progresses and indications expand, it remains essential to continue investigations of both robotic instrumentation and ARSN to validate meaningful benefit over conventional instrumentation techniques in spine surgery

Long-Term Outcomes Following Conventionally Fractionated Stereotactic Boost for High-Grade Gliomas in Close Proximity to Critical Organs at Risk

Purpose/Objective: High-grade glioma is the most common primary malignant tumor of the CNS, with death often resulting from uncontrollable intracranial disease. Radiation dose may be limited by the tolerance of critical structures, such as the brainstem and optic apparatus. In this report, long-term outcomes in patients treated with conventionally fractionated stereotactic boost for tumors in close proximity to critical structures are presented.Materials/Methods: Patients eligible for inclusion in this single institution retrospective review had a pathologically confirmed high-grade glioma status post-surgical resection. Inclusion criteria required tumor location within one centimeter of a critical structure, including the optic chiasm, optic nerve, and brainstem. Radiation therapy consisted of external beam radiation followed by a conventionally fractionated stereotactic boost. Oncologic outcomes and toxicity were assessed.Results: Thirty patients eligible for study inclusion underwent resection of a high-grade glioma. The median initial adjuvant EBRT dose was 50 Gy with a median conventionally fractionated stereotactic boost of 10 Gy. All stereotactic treatments were given in 2 Gy daily fractions. Median follow-up time for the entire cohort was 38 months with a median overall survival of 45 months and 5-year overall survival of 32.5%. The median freedom from local progression was 45 months, and the 5-year freedom from local progression was 29.7%. Two cases of radiation retinopathy were identified following treatment. No patient experienced toxicity attributable to the optic chiasm, optic nerve, or brainstem and no grade 3+ radionecrosis was observed.Conclusions: Oncologic and toxicity outcomes in high-grade glioma patients with tumors in unfavorable locations treated with conventionally fractionated stereotactic boost are comparable to those reported in the literature. This treatment strategy is appropriate for those patients with resected high-grade glioma in close proximity to critical structures

Diagnostic, Surgical, and Technical Considerations for Lumbar Interbody Fusion in Patients with Osteopenia and Osteoporosis: A Systematic Review

Objective: Osteoporosis is increasing in incidence as the ageing population continues to grow. Decreased bone mineral density poses a challenge for the spine surgeon. In patients requiring lumbar interbody fusion, differences in diagnostics and surgical approaches may be warranted. In this systematic review, the authors examine studies performing lumbar interbody fusion in patients with osteopenia or osteoporosis and suggest avenues for future study. Methods: A systematic literature review of the PubMed and MEDLINE databases was performed for studies published between 1986 and 2020. Studies evaluating diagnostics, surgical approaches, and other technical considerations were included. Results: A total of 13 articles were ultimately selected for qualitative analysis. This includes studies demonstrating the utility of Hounsfield units in diagnosis, a survey of surgical approaches, as well as exploring the use of vertebral augmentation and cortical bone screw trajectory. Conclusions: This systematic review provides a summary of preliminary findings with respect to the use of Hounsfield units as a diagnostic tool, the benefit or lack thereof with respect to minimally invasive approaches, and the question of whether or not cement augmentation or cortical bone trajectory confers benefit in osteoporotic patients undergoing lumbar interbody fusion. While the findings of these studies are promising, the current state of the literature is limited in scope and, for this reason, definitive conclusions cannot be drawn from these data. The authors highlight gaps in the literature and the need for further exploration and study of lumbar interbody fusion in the osteoporotic spine

Fiducial-free CyberKnife stereotactic body radiation therapy (SBRT) for single vertebral body metastases: acceptable local control and normal tissue tolerance with 5 fraction approach

This retrospective analysis examines the local control and toxicity of 5 fraction fiducial-free CyberKnife stereotactic body radiation therapy (SBRT) for single vertebral body metastases. All patients had favorable performance status (ECOG 0-1), oligometastatic disease and no prior spine irradiation. A prescribed dose of 30 to 35 Gy was delivered in 5 fractions to the planning treatment volume (PTV) using the CyberKnife with X-sight spine tracking. Suggested maximum spinal cord and esophagus point doses were 30 Gy and 40 Gy, respectively. A median 30 Gy (range, 30 - 35 Gy) dose was delivered to a median prescription isodose line of 70% (range, 60 - 80%) to 20 patients. At 34 months median follow-up (range, 12-62 months) for surviving patients, the 1- and 2-year Kaplan-Meier local control estimates were 80% and 73%, respectively. Two of the 5 local failures were infield in patients who had received partial vertebral body irradiation and 3 were paravertebral failures just outside the PTV in patients with prior corpectomy. No local failures occurred in patients who completed total vertebral body radiation alone. The 1- and 2-year Kaplan-Meier overall survival estimates were 80% and 57%, respectively. Most deaths were attributed to metastatic disease; one death was attributed to local recurrence. The mean maximum point doses were 26.4 Gy (range, 16.3 - 31.8 Gy) to the spinal cord and 30.7 Gy (15.4- 40.0 Gy) to the esophagus. Patients receiving maximum esophagus point doses greater than 35 Gy experienced acute dysphagia (Grade I/II). No spinal cord toxicity was documented. Five fraction fiducial-free CyberKnife SBRT is an acceptable treatment option for newly diagnosed vertebral body metastases with promising local control rates and minimal toxicity despite the close proximity of such tumors to the spinal cord and esophagus. A prospective study aimed at further enhancing local control by targeting the entire intact vertebral body and escalating the total dose is planne