100 Complex posterior spinal fusion cases performed with robotic instrumentation.

Robotic navigation has been shown to increase precision, accuracy, and safety during spinal reconstructive procedures. There is a paucity of literature describing the best techniques for robotic-assisted spine surgery for complex, multilevel cases or in cases of significant deformity correction. We present a case series of 100 consecutive multilevel posterior spinal fusion procedures performed for multilevel spinal disease and/or deformity correction. 100 consecutive posterior spinal fusions were performed for multilevel disease and/or deformity correction utilizing robotic-assisted placement of pedicle screws. The primary outcome was surgery-related failure, which was defined as hardware breakage or reoperation with removal of hardware. A total of 100 consecutive patients met inclusion criteria. Among cases included, 31 were revision surgeries with existing hardware in place. The mean number of levels fused was 5.6, the mean operative time was 303 min, and the mean estimated blood loss was 469 mL. 28 cases included robotic-assisted placement of S2 alar-iliac (S2AI) screws. In total, 1043 pedicle screws and 53 S2AI screws were placed with robotic-assistance. The failure rate using survivorship analysis was 18/1043 (1.7%) and the failure rate of S2AI screws using survivorship analysis was 3/53 (5.7%). Four patients developed postoperative wound infections requiring irrigation and debridement procedures. None of the 1043 pedicle screws nor the 53 S2AI screws required reoperation due to malpositioning or suboptimal placement. This case series of 100 multilevel posterior spinal fusion procedures demonstrates promising results with low failure rates. With 1043 pedicle screws and 53 S2AI screws, we report low failure rates of 1.7% and 5.7%, respectively with zero cases of screw malpositioning. Robotic screw placement allows for accurate screw placement with no increased rate of postoperative infection compared to historical controls. Level of evidence: IV, Retrospective review.

Augmented Reality Spine Surgery Navigation: Increasing Pedicle Screw Insertion Accuracy for Both Open and Minimally Invasive Spine Surgeries.

STUDY DESIGN: Collectively, seven cadavers were instrumented with 124 thoracolumbar pedicle screws using VisAR augmented reality/guidance. Sixty-five screws were inserted into four donors using open dissection spine surgery. Fifty-nine screws were positioned in three donors with a minimally invasive spine surgery (MISS) procedure. For both open and MISS, VisAR was used exclusively for pedicle screw navigation. OBJECTIVE: The objective of this study was to determine the accuracy of pedicle screw placement using VisAR for open spine and MISS procedures. SUMMARY OF BACKGROUND DATA: Pedicle screw placement can be challenging depending on anatomical location and a surgeon's experience. AR may minimize fluoroscopy use and speed screw insertion. METHODS: Prior to computed tomography (CT) a series of four image visible April Tag optical fiducials were attached to the backs' of the donors. Resulting images were used preoperatively for planned virtual pedicle screw pathways including entry point, trajectory, and depth. The study link was encrypted on a quick response (QR) code, printed, and viewed in the operating room (OR) by the surgeon using VisAR (HoloLens 2 headset). Viewing the code wirelessly uploads and launches the study, converting the DICOM data to holographic images which register to the fiducials on the donor's back. The annotated pathways for each pedicle were called up by voice command and the surgeon positioned each screw by aligning with the virtual guidance hologram. RESULTS: Overall, 124 pedicle screws were inserted with VisAR navigation with 96% accuracy (Gertzbein-Robbins grades A and B). The combined angle of error was 2.4° and the distance error was 1.9 mm. CONCLUSION: Augmented reality is a highly accurate, emerging technology for navigating both open and minimally invasive spine surgery techniques with off-the-shelf headset hardware. LEVEL OF EVIDENCE: N/A.

Prospective comparison of dysphagia following anterior cervical discectomy and fusion (ACDF) with and without rhBMP-2.

BACKGROUND CONTEXT: Previous studies have called into question the safety of using rhBMP-2 in anterior cervical fusion due to the possibility of airway compromise and dysphagia. A retrospective chart review identified a significant increase in the severity of dysphagia after II-level ACDF with rhBMP-2 compared to patients who did not receive rhBMP-2. To date, this topic has not been studied prospectively. PURPOSE: Compare the incidence of dysphagia following anterior cervical discectomy and fusion (ACDF) when recombinant human bone morphogenetic protein-2 (rhBMP-2) is used with allograft compared to allograft alone. STUDY DESIGN: Prospective cohort study. PATIENT SAMPLE: A total of 114 patients completed a baseline SWAL-QOL survey and met the inclusion criteria. Thirty-nine patients underwent I- or II-level ACDF with allograft plus 0.5mg rhBMP-2/level. 44 patients underwent ACDF with allograft alone. Thirty-one patients undergoing a lumbar decompression were enrolled in a third cohort to control for dysphagia secondary to intubation. OUTCOME MEASURES: The primary outcome measure was the 14-point SWAL-QOL dysphagia questionnaire. Other patient factors obtained from anesthesia and operative records were examined to evaluate their potential relationship to postoperative dysphagia. METHODS: The 14-point SWAL-QOL questionnaire was administered at multiple time points (pre-op, post-op 7 days, 6 weeks, 6 months, and at least 1 year). Multivariable repeated-measures analysis was applied to data. RESULTS: Baseline adjusted SWAL-QOL means 7 days after surgery were significantly different between the three study groups. These differences resolved by 6 weeks postoperative, beyond which point there were no differences. At final follow-up, baseline adjusted SWAL-QOL means at 1 year were similar for the three study groups. CONCLUSIONS: This single-center study of anterior cervical surgery demonstrated that the addition of rhBMP-2 to an ACDF increased postoperative dysphagia at 7 days after surgery, but these patients recover to levels comparable to those who underwent ACDF without rhBMP-2 or lumbar surgery within 6 weeks.

Cadaver training module for teaching thoracic pedicle screw placement to residents.

Surgical training using simulators has been shown to be highly effective but is not available for some applications and is too expensive for many programs. The authors piloted a cadaver-based module with the goal of objectively measuring and significantly improving orthopedic residents' surgical skills in placing thoracic pedicle screws, an advanced procedure. An experienced spine surgeon placed thoracic pedicle screws in 7 cadavers (T1-T12) to establish the skilled accuracy rate. For this pilot study, 3 orthopedic residents unfamiliar with the procedure were given didactic training for safe thoracic pedicle screw insertion. Each resident instrumented alternating sides of 5 consecutive cadavers (T1-T12). Screw positions were graded by computed tomography in a blinded fashion, with accuracy defined as no shank breach of the pedicle or vertebral body. Results were reviewed with the residents, instruction was repeated, and alternating sides of 5 cadavers were instrumented by the residents. The experienced surgeon accurately placed 67 (82%) of 82 pedicle screws. Residents accurately placed 80 (44%) of 180 pedicle screws in the initial set of specimens and 105 (58%) of 180 pedicle screws in the second set of specimens (P=.01). Accuracy varied significantly among residents before but not after computed tomography review. The study's results show that a cadaver-based training module that resembles the clinical setting can be used to teach complex surgical skills to orthopedic residents.

Transforaminal lumbar interbody fusion and posterior lumbar interbody fusion utilizing BMP-2 in treatment of degenerative spondylolisthesis: neither safe nor cost effective.

BACKGROUND: With the rise of health care costs, there is increased emphasis on evaluating the cost of a particular surgical procedure for quality adjusted life year (QALY) gained. Recent data have shown that surgical intervention for the treatment of degenerative spondylolisthesis (DS) is as cost-effective as total joint arthroplasty. Despite these excellent outcomes, some argue that the addition of interbody fusion supplemented with bone morphogenetic protein (BMP) enhances the value of this procedure. METHODS: This review examines the current research regarding the cost-effectiveness of the surgical management of lumbar DS utilizing interbody fusion along with BMP. RESULTS: Posterolateral spinal fusion with instrumentation for focal lumbar spinal stenosis with DS can provide and maintain improvement in self-reported quality of life. Based on the available literature, including nonrandomized comparative studies and case series, the addition of interbody fusion along with BMP does not lead to significantly better clinical outcomes and increases costs when compared with more routine posterolateral fusion techniques. CONCLUSIONS: To enhance the value of the surgical management for DS, costs must decrease or there should be substantial improvement in effectiveness as measured by clinical outcomes. To date, there is insufficient evidence to support the use of interbody fusion devices along with BMP to treat routine cases of focal stenosis accompanied by DS, which are routinely adequately treated utilizing posterolateral fusion techniques.

Cervical disc arthroplasty: Pros and cons.

BACKGROUND: Cervical disc arthroplasty has emerged as a promising potential alternative to anterior cervical discectomy and fusion (ACDF) in appropriately selected patients. Despite a history of excellent outcomes after ACDF, the question as to whether a fusion leads to adjacent segment degeneration remains unanswered. Numerous US investigational device exemption trials comparing cervical arthroplasty to fusion have been conducted to answer this question. METHODS: This study reviews the current research regarding cervical athroplasty, and emphasizes both the pros and cons of arthroplasty as compared with ACDF. RESULTS: Early clinical outcomes show that cervical arthroplasty is as effective as the standard ACDF. However, this new technology is also associated with an expanding list of novel complications. CONCLUSION: Although there is no definitive evidence that cervical disc replacement reduces the incidence of adjacent segment degeneration, it does show other advantages; for example, faster return to work, and reduced need for postoperative bracing.