Pedicle Screw Placement Accuracy in Robot-Assisted Spinal Fusion in a Multicenter Study.

Pedicle screw fixation is a spinal fusion technique that involves the implantation of screws into vertebral pedicles to restrict movement between those vertebrae. The objective of this research is to measure pedicle screw placement accuracy using a novel automated measurement system that directly compares the implanted screw location to the planned target in all three anatomical views. Preoperative CT scans were used to plan the screw trajectories in 122 patients across four surgical centers. Postoperative scans were fused to the preoperative plan to quantify placement accuracy using an automated measurement algorithm. The mean medial-lateral and superior-inferior deviations in the pedicle region for 500 screws were 1.75 ± 1.36 mm and 1.52 ± 1.26 mm, respectively. These deviations were measured using an automated system and were statistically different from manually determined values. The uncertainty associated with the fusion of preoperative to postoperative images was also quantified to better understand the screw-to-plan accuracy results. This study uses a novel automated measurement system to quantify screw placement accuracy as it relates directly to the planned target location, instead of analyzing for breaches of the pedicle, to quantify the validity of using of a robotic-guidance system for accurate pedicle screw placement.

Management of Anticoagulation/Antiplatelet Medication and Venous Thromboembolism Prophylaxis in Elective Spine Surgery: Concise Clinical Recommendations Based on a Modified Delphi Process.

STUDY DESIGN: Delphi method. OBJECTIVE: To gain consensus on the following questions: (1) When should anticoagulation/antiplatelet (AC/AP) medication be stopped before elective spine surgery?; (2) When should AC/AP medication be restarted after elective spine surgery?; (3) When, how, and in whom should venous thromboembolism (VTE) chemoprophylaxis be started after elective spinal surgery? SUMMARY OF BACKGROUND DATA: VTE can lead to significant morbidity after adult spine surgery, yet postoperative VTE prophylaxis practices vary considerably. The management of preoperative AC/AP medication is similarly heterogeneous. MATERIALS AND METHODS: Delphi method of consensus development consisting of three rounds (January 26, 2021, to June 21, 2021). RESULTS: Twenty-one spine surgeons were invited, and 20 surgeons completed all rounds of questioning. Consensus (>70% agreement) was achieved in 26/27 items. Group consensus stated that preoperative Direct Oral Anticoagulants should be stopped two days before surgery, warfarin stopped five days before surgery, and all remaining AC/AP medication and aspirin should be stopped seven days before surgery. For restarting AC/AP medication postoperatively, consensus was achieved for low-risk/medium-risk/high-risk patients in 5/5 risk factors (VTE history/cardiac/ambulation status/anterior approach/operation). The low/medium/high thresholds were POD7/POD5/POD2, respectively. For VTE chemoprophylaxis, consensus was achieved for low-risk/medium-risk/high-risk patients in 12/13 risk factors (age/BMI/VTE history/cardiac/cancer/hormone therapy/operation/anterior approach/staged separate days/staged same days/operative time/transfusion). The one area that did not gain consensus was same-day staged surgery. The low-threshold/medium-threshold/high-threshold ranges were postoperative day 5 (POD5) or none/POD3-4/POD1-2, respectively. Additional VTE chemoprophylaxis considerations that gained consensus were POD1 defined as the morning after surgery regardless of operating finishing time, enoxaparin as the medication of choice, and standardized, rather than weight-based, dose given once per day. CONCLUSIONS: In the first known Delphi study to address anticoagulation/antiplatelet recommendations for elective spine surgery (preoperatively and postoperatively); our Delphi consensus recommendations from 20 spine surgeons achieved consensus on 26/27 items. These results will potentially help standardize the management of preoperative AC/AP medication and VTE chemoprophylaxis after adult elective spine surgery.

Medialized, Muscle-Splitting Approach for Posterior Lumbar Interbody Fusion: Technique and Multicenter Perioperative Results.

STUDY DESIGN: Retrospective, multicenter study of perioperative results OBJECTIVE.: The purpose of this study was to describe the surgical technique for medialized posterior lumbar fusion as well as present preliminary complication and treatment results from a multicenter retrospective study. SUMMARY OF BACKGROUND DATA: Posterior exposures remain the most commonly performed approaches for spinal fusion. Conventional open posterior exposures, however, have relatively high exposure-related morbidity and postoperative infection rates. Less invasive exposures for transforaminal and anterior (lateral) interbody fusion have been widely used over the past decade, but the need for bilateral posterior exposure has challenged the development of less invasive exposures for direct posterior approaches for lumbar fusion. METHODS: Consecutive patients treated with minimally invasive spine (MIS) posterior lumbar interbody fusion with medialized cortical bone trajectory pedicle screw and rod fixation were identified from four sites in the United States. Of the 138 patients identified, 61% of patients were treated for degenerative spondylolisthesis at 167 levels, most commonly at L4-5 (62%). Perioperative treatment, complication, and reoperation data were collected to describe early feasibility of the approach. RESULTS: Mean total operative time was 135 minutes with an average of 236  mL of blood loss. Mean total postoperative length of hospital stay was 2.6 days, with 25% of patients discharged on the same day or within 23 hours of surgery. Total perioperative complication rate in 138 patients was 10.1% (14/138) with three related reoperations. Intraoperative complications included five (3.6%) instances of incidental durotomy, without any progression to persistent cerebrospinal fluid leaks. Nine (6.5%) postoperative complications occurred, including one L5 vertebral body fracture, two pulmonary embolisms, one deep vein thrombosis, one urinary tract infection one instance of urinary retention, two superficial surgical site infections, and one patient with persistent pain at 6 months postoperative. Three (2.2%) reoperations were performed, one for revision of the L5 vertebral body fracture, and two for wound debridement. No instances of postoperative radiculitis or neurological injury were observed. CONCLUSION: Medialized, muscle-sparing posterior exposures with specialized instrumentation can be performed in patients with degenerative lumbar pathology with low surgical morbidity and blood loss and a short length of postoperative hospital stay. LEVEL OF EVIDENCE: 4.

Mortality and morbidity associated with correction of severe cervical hyperextension.

STUDY DESIGN: Three case reports of patients with treatment of severe cervical hyperextension. OBJECTIVE: Cervical hyperextension is a rare spine deformity that is associated with myopathies. Previous reports of surgical correction have reported no major operative complications. This report outlines our experience with 3 patients who experienced significant complications. SUMMARY OF BACKGROUND DATA: The limited literature on the treatment of cervical hyperextension has good to excellent outcomes. METHODS: Three case reports are presented. RESULTS: Three cases with severe cervical hyperextension with intraoperative correction had associated morbidity and mortality. One case had a failed intubation requiring tracheotomy. This was followed by a successful posterior release with halo traction for 2 weeks and then an instrumented posterior cervical fusion. This patient died at home 2 weeks after surgery. The second and third cases had an intraoperative spinal cord injury during a posterior release for cervical hyperextension. CONCLUSION: Patients with severe cervical hyperextension have high neurologic perioperative risk.