Surgical Complications of Spinal Deformity Surgery

Multidisciplinary approaches to complication reduction in complex spine surgery: a systematic review

BACKGROUND CONTEXT

Complex spine surgery carries a high complication rate that can produce suboptimal outcomes for patients undergoing these extensive operations. However, multidisciplinary pathways introduced at multiple institutions have demonstrated a promising potential toward reducing the burden of complications in patients being treated for spinal deformities. To date, there has been no effort to systematically collate the multidisciplinary approaches in use at various institutions.

PURPOSE

The present study aims to determine effective multidisciplinary strategies for reducing the complication rate in complex spine surgery by analyzing existing institutional multidisciplinary approaches and delineating common themes across multiple practice settings.

STUDY DESIGN

Systematic review.

METHODS

We followed guidelines established under the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The studies reported on data from PubMed, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science and Cochrane. We included articles that described either approaches to, or results from, the implementation of multidisciplinary paradigms during the preoperative, perioperative, and postoperative phases of care for patients undergoing complex spine surgery. We excluded studies that only targeted one complication unless such an approach was in coordination with more extensive multidisciplinary planning at the same institution.

RESULTS

A total of 406 unique articles were identified. Following an initial determination based on title and abstract, 22 articles met criteria for full-text review, and 10 met the inclusion criteria to be included in the review. Key aspects of multidisciplinary approaches to complex spine surgery included extensive preoperative workup and interdisciplinary conferencing, intraoperative communication and monitoring, and postoperative floor management and discharge planning. These strategies produced decreases in surgical duration and complication rates.

CONCLUSIONS

This study represents the first to systematically analyze multidisciplinary approaches to reduce complications in complex spine surgery. This review provides a roadmap toward reducing the elevated complication rate for patients undergoing complex spine surgery.

The Arrival of Robotics in Spine Surgery: A Review of the Literature

STUDY DESIGN

Systematic review.

OBJECTIVE

The authors aim to review comparative outcome measures between robotic and free-hand spine surgical procedures including: accuracy of spinal instrumentation, radiation exposure, operative time, hospital stay, and complication rates.

SUMMARY OF BACKGROUND DATA

Misplacement of pedicle screws in conventional open as well as minimally invasive surgical procedures has prompted the need for innovation and allowed the emergence of robotics in spine surgery. Before incorporation of robotic surgery in routine practice, demonstration of improved instrumentation accuracy, operative efficiency, and patient safety are required.

METHODS

A systematic search of the PubMed, OVID-MEDLINE, and Cochrane databases was performed for articles relevant to robotic assistance of pedicle screw placement. Inclusion criteria were constituted by English written randomized control trials, prospective and retrospective cohort studies involving robotic instrumentation in the spine. Following abstract, title, and full-text review, 32 articles were selected for study inclusion.

RESULTS

Intrapedicular accuracy in screw placement and subsequent complications were at least comparable if not superior in the robotic surgery cohort. There is evidence supporting that total operative time is prolonged in robot-assisted surgery compared to conventional free-hand. Radiation exposure appeared to be variable between studies; radiation time did decrease in the robot arm as the total number of robotic cases ascended, suggesting a learning curve effect. Multilevel procedures appeared to tend toward earlier discharge in patients undergoing robotic spine surgery.

CONCLUSION

The implementation of robotic technology for pedicle screw placement yields an acceptable level of accuracy on a highly consistent basis. Surgeons should remain vigilant about confirmation of robotic-assisted screw trajectory, as drilling pathways have been shown to be altered by soft tissue pressures, forceful surgical application, and bony surface skiving. However, the effective consequence of robot-assistance on radiation exposure, length of stay, and operative time remains unclear and requires meticulous examination in future studies.

LEVEL OF EVIDENCE

4.

Sagittal imbalance treated with L5 pedicle subtraction osteotomy with short lumbar fusion from L4 to sacrum using four screws into L4 for enhanced fixation two additional vertebral screws: a technical note

PURPOSE

To report on suggested technique with four screws in a single vertebra (two pedicle screws and two direct vertebral body screws) for enhanced fixation with just one level cranially to a pedicle subtraction osteotomy (PSO).

METHODS

A 60-year-old woman underwent L4/5 fusion surgery for degenerative spondylolisthesis. Two years later, she was unable to stand upright even for a short time because of lumbar kyphosis caused by subsidence of the fusion cage and of Baastrup syndrome in the upper lumbar spine [sagittal vertical axis (SVA) of 114 mm, pelvic incidence of 75°, and lumbar lordosis (LL) of 41°]. She underwent short-segment fusion from L4 to the sacrum with L5 pedicle subtraction osteotomy. We reinforced the construct with two vertebral screws at L4 in addition to the conventional L4 pedicle screws.

RESULTS

After the surgery, her sagittal parameters were improved (SVA, 36 mm; LL, 54°). Two years after the corrective surgery, she maintained a low sagittal vertical axis though high residual pelvic tilt indicated that the patient was still compensating for residual sagittal misalignment.

CONCLUSION

PSO surgery for sagittal imbalance usually requires a long fusion at least two levels above and below the osteotomy site to achieve adequate stability and better global alignment. However, longer fixation may decrease the patients' quality of life and cause a proximal junctional failure. Our novel technique may shorten the fixation area after osteotomy surgery. These slides can be retrieved under Electronic Supplementary Material.

Forces in spinal cannulation and breaches ex vivo

BACKGROUND

Pedicle screw insertion, to stabilize or correct the spine, relies on creating a probe path with the correct trajectory to prevent unsafe breaching of the cortical wall. Safe pedicle cannulation is aided when the surgeon can feel the difference between a safe and unsafe path. Pedicle probe forces and torques are currently unknown. The purpose of this study was to investigate the forces and torques encountered while cannulating the pedicle tract in both correct and incorrect cannulations.

METHODS

Two experienced surgeons used a standard lumbar probe modified to incorporate a 6 degree-of-freedom load cell to cannulate and breach the T12 to S1 vertebrae of six fresh frozen cadavers (3 males, 3 females, ages 65 to 92). A total of 76 pedicles were tested.

FINDINGS

Cannulation axial forces averaged 48 N (standard deviation = 13 N), medial breach 129 N (standard deviation = 25 N), and lateral breach 86 N (standard deviation = 27 N). Cannulation values were significantly lower than the breach values in all 6 degrees of freedom (p < 0.001). There were significant differences between specimens, including males and females, and between degrees of freedom, but no significant right and left differences or by vertebral level.

CONCLUSION

A large range of cannulation and breach forces and torques were measured due to variations in bone quality and geometry, as experienced clinically. This is the first time that the absolute and relative force and torque levels have been reported, to our knowledge.

Clinical acceptance and accuracy assessment of spinal implants guided with SpineAssist surgical robot: retrospective study

STUDY DESIGN

Retrospective, multicenter study of robotically-guided spinal implant insertions. Clinical acceptance of the implants was assessed by intraoperative radiograph, and when available, postoperative computed tomography (CT) scans were used to determine placement accuracy.

OBJECTIVE

To verify the clinical acceptance and accuracy of robotically-guided spinal implants and compare to those of unguided free-hand procedures.

SUMMARY OF BACKGROUND DATA

SpineAssist surgical robot has been used to guide implants and guide-wires to predefined locations in the spine. SpineAssist which, to the best of the authors' knowledge, is currently the sole robot providing surgical assistance in positioning tools in the spine, guided over 840 cases in 14 hospitals, between June 2005 and June 2009.

METHODS

Clinical acceptance of 3271 pedicle screws and guide-wires inserted in 635 reported cases was assessed by intraoperative fluoroscopy, where placement accuracy of 646 pedicle screws inserted in 139 patients was measured using postoperative CT scans.

RESULTS

Screw placements were found to be clinically acceptable in 98% of the cases when intraoperatively assessed by fluoroscopic images. Measurements derived from postoperative CT scans demonstrated that 98.3% of the screws fell within the safe zone, where 89.3% were completely within the pedicle and 9% breached the pedicle by up to 2 mm. The remaining 1.4% of the screws breached between 2 and 4 mm, while only 2 screws (0.3%) deviated by more than 4 mm from the pedicle wall. Neurologic deficits were observed in 4 cases yet, following revisions, no permanent nerve damage was encountered, in contrast to the 0.6% to 5% of neurologic damage reported in the literature.

CONCLUSION

SpineAssist offers enhanced performance in spinal surgery when compared to free-hand surgeries, by increasing placement accuracy and reducing neurologic risks. In addition, 49% of the cases reported herein used a percutaneous approach, highlighting the contribution of SpineAssist in procedures without anatomic landmarks.