Eric A. Potts

A comparison of two techniques in image-guided thoracic pedicle screw placement: a retrospective study of 37 patients and 277 pedicle screws

OBJECTnThe goal of this study was to compare the accuracy of thoracic pedicle screw placement aided by two different image-guidance modalities.nnnMETHODSnThe charts of 40 consecutive patients who had undergone stabilization of the thoracic spine between January 2003 and January 2005 were retrospectively reviewed. Three patients were excluded from the study because, on the basis of preoperative findings, small pedicle diameter precluded the use of pedicle screws. Thus, a total of 37 patients had 277 screws placed with the aid of either virtual fluoroscopy or isocentric C-arm 3D navigation. The indications for surgery included trauma, degenerative disease, and tumor, and were similar in both groups. All 37 patients underwent postoperative computed tomography scanning, and an independent reviewer graded all screws based on axial, sagittal, and coronal projections for a full determination of the placement of the screw in the pedicle.nnnRESULTSnThe rate of unintended perforations was found to depend on pedicle diameter (p < 0.0001). There were no statistical differences between groups with regard to rate or grade of cortical perforations. Overall, the rate and grade of perforations was low, and there were no neurological or vascular complications.nnnCONCLUSIONSnThe authors have shown that either image-guidance system may be used with a high degree of accuracy and safety. Because both systems were found to be comparably safe and accurate, the choice of image-guidance modality may be determined by the level of surgeon comfort and/or availability of the system.

Intraoperative cone beam-computed tomography with navigation (O-ARM) versus conventional fluoroscopy (C-ARM): a cadaveric study comparing accuracy, efficiency, and safety for spinal instrumentation.

Study Design. Cadaveric laboratory study. Objective. To compare the accuracy, efficiency, and safety of intraoperative cone beam–computed tomography with navigation (O-ARM) with traditional intraoperative fluoroscopy (C-ARM) for the placement of pedicle screws. Summary of Background Data. Radiation exposure remains a concern with traditional methods of intraoperative imaging in spine surgery. The use of O-ARM has been proposed for more accurate and efficient spinal instrumentation. Understanding radiation imparted to patients and surgeons by O-ARM is important for assessing risks and benefits of this technology, especially in light of evolving indications. Methods. Four surgeons placed 160 pedicle screws on 8 cadavers without deformity. Eighty pedicle screws were placed using O-ARM and C-ARM each. Instrumentation was placed bilaterally in the thoracic (T1–T6) spine and lumbosacral junction (L5–S1) using a standard open technique, whereas minimally invasive surgery technique was used at the lumbar 3 to 4 (L3–L4) level. A “postoperative” computed tomography (CT) scan was performed on cadavers where instrumentation was done using the C-ARM. An independent musculoskeletal radiologist assessed final images for screw position. Time required to set up and instrumentation was recorded. Dosimeters were placed on multiple aspects of cadavers and surgeons to record radiation exposure. Results. There were no differences in breach rate between the O-ARM and C-ARM groups (5 vs. 7, &khgr;2= 0.63, P = 0.4). The setup time for the O-ARM group was longer than that for the C-ARM group (592 vs. 297 s, P < 0.05). However, the average total time was statistically the same (1629 vs. 1639 s, P = 0.96). Radiation exposure was higher for surgeons in the C-ARM group and cadavers in the O-ARM group. When a “postoperative” CT scan was included in the estimation of the total radiation exposure, there was less of difference between the groups, but still more for the O-ARM group. Conclusion. In cadavers without deformity, O-ARM use results in similar breach rates as C-ARM for the placement of pedicle screws. Time for instrumentation is shorter with the O-ARM, but requires a longer setup time. The O-ARM exposes less radiation to the surgeon, but higher doses to the cadaver. Level of Evidence: N/A

Percutaneous pedicle screw instrumentation for temporary internal bracing of nondisplaced bony Chance fractures.

Objective and Importance Although many patients with unstable Chance fractures can heal in an external brace, others will require internal stabilization. Short-segment minimally invasive internal bracing of a Chance fracture offers the rigidity and patient compliance of internal bracing with minimal tissue disruption. This technique has not yet been described. Clinical Presentation A healthy 16-year-old female and 21-year-old male sustained classic nondisplaced Chance fractures. They were both neurologically intact. Technique An image-guided Jamshidi needle was used to percutaneously place K-wires to direct percutaneous pedicle screws. Freehand percutaneous passing of rods to connect the pedicle screw heads on each side created a short-segment construct. Conclusions Minimally invasive internal bracing of nondisplaced bony Chance fractures is an option for selected neurologically intact patients unable to tolerate external bracing.

A Survey-Based Study of Wrong-Level Lumbar Spine Surgery: The Scope of the Problem and Current Practices in Place to Help Avoid These Errors

OBJECTIVEnTo understand better the scope of wrong-level lumbar spine surgery and current practices in place to help avoid such errors.nnnMETHODSnThe Joint Section on Disorders of the Spine and Peripheral Nerves (Spine Section) developed a survey on single-level lumbar spine decompression surgery. Invitations to complete the Web-based survey were sent to all Spine Section members. Respondents were assured of confidentiality.nnnRESULTSnThere were 569 responses from 1045 requests (54%). Most surgeons either routinely (74%) or sometimes (11%) obtain preoperative imaging for incision planning. Most surgeons indicated that they obtained imaging after the incision was performed for localization either routinely before bone removal (73%) or most frequently before bone removal but occasionally after (16%). Almost 50% of reporting surgeons have performed wrong-level lumbar spine surgery at least once, and >10% have performed wrong-side lumbar spine surgery at least once. Nearly 20% of responding surgeons have been the subject of at least one malpractice case relating to these errors. Only 40% of respondents believed that the site marking/time out protocol of The Joint Commission on the Accreditation of Healthcare Organizations has led to a reduction in these errors.nnnCONCLUSIONSnThere is substantial heterogeneity in approaches used to localize operative levels in the lumbar spine. Existing safety protocols may not be mitigating wrong-level surgery to the extent previously thought.

Minimally invasive versus open fusion for Grade I degenerative lumbar spondylolisthesis: analysis of the Quality Outcomes Database

OBJECTIVE Lumbar spondylolisthesis is a degenerative condition that can be surgically treated with either open or minimally invasive decompression and instrumented fusion. Minimally invasive surgery (MIS) approaches may shorten recovery, reduce blood loss, and minimize soft-tissue damage with resultant reduced postoperative pain and disability. METHODS The authors queried the national, multicenter Quality Outcomes Database (QOD) registry for patients undergoing posterior lumbar fusion between July 2014 and December 2015 for Grade I degenerative spondylolisthesis. The authors recorded baseline and 12-month patient-reported outcomes (PROs), including Oswestry Disability Index (ODI), EQ-5D, numeric rating scale (NRS)-back pain (NRS-BP), NRS-leg pain (NRS-LP), and satisfaction (North American Spine Society satisfaction questionnaire). Multivariable regression models were fitted for hospital length of stay (LOS), 12-month PROs, and 90-day return to work, after adjusting for an array of preoperative and surgical variables. RESULTS A total of 345 patients (open surgery, n = 254; MIS, n = 91) from 11 participating sites were identified in the QOD. The follow-up rate at 12 months was 84% (83.5% [open surgery]; 85% [MIS]). Overall, baseline patient demographics, comorbidities, and clinical characteristics were similarly distributed between the cohorts. Two hundred fifty seven patients underwent 1-level fusion (open surgery, n = 181; MIS, n = 76), and 88 patients underwent 2-level fusion (open surgery, n = 73; MIS, n = 15). Patients in both groups reported significant improvement in all primary outcomes (all p < 0.001). MIS was associated with a significantly lower mean intraoperative estimated blood loss and slightly longer operative times in both 1- and 2-level fusion subgroups. Although the LOS was shorter for MIS 1-level cases, this was not significantly different. No difference was detected with regard to the 12-month PROs between the 1-level MIS versus the 1-level open surgical groups. However, change in functional outcome scores for patients undergoing 2-level fusion was notably larger in the MIS cohort for ODI (-27 vs -16, p = 0.1), EQ-5D (0.27 vs 0.15, p = 0.08), and NRS-BP (-3.5 vs -2.7, p = 0.41); statistical significance was shown only for changes in NRS-LP scores (-4.9 vs -2.8, p = 0.02). On risk-adjusted analysis for 1-level fusion, open versus minimally invasive approach was not significant for 12-month PROs, LOS, and 90-day return to work. CONCLUSIONS Significant improvement was found in terms of all functional outcomes in patients undergoing open or MIS fusion for lumbar spondylolisthesis. No difference was detected between the 2 techniques for 1-level fusion in terms of patient-reported outcomes, LOS, and 90-day return to work. However, patients undergoing 2-level MIS fusion reported significantly better improvement in NRS-LP at 12 months than patients undergoing 2-level open surgery. Longer follow-up is needed to provide further insight into the comparative effectiveness of the 2 procedures.

Comparison Perioperative Factors During Minimally Invasive Pre-Psoas Lateral Interbody Fusion of the Lumbar Spine Using Either Navigation or Conventional Fluoroscopy

Study Design: Retrospective clinical study. Objectives: The aim of this study was to compare intraoperative conditions and clinical results of patients undergoing pre-psoas oblique lateral interbody fusion (OLIF) using navigation or conventional fluoroscopy (C-ARM) techniques. Methods: Forty-two patients (22 patients by navigation and 20 by fluoroscopy) underwent the OLIF procedure at 2 medical centers, and records were reviewed. Clinical data was collected and compared between the 2 groups. Patients were followed-up with a range of 6 to 24 months. Results: There were no significant differences on demographic data between groups. The navigation group had zero radiation exposure (RE) to the surgeon and radiation time compared to the C-ARM group, with total RE of 44.59 ± 26.65u2009mGy and radiation time of 88.30 ± 58.28 seconds (P < .05). The RE to the patient was significantly lower in the O-ARM group (9.38u2009mGy) compared to the C-ARM group (44.59 ± 26.65u2009mGy). Operating room time was slightly longer in the navigation group (2.49 ± 1.35u2009hours) compared to the C-ARM group (2.30 ± 1.17u2009hours; P > .05), although not statistically significant. No differences were found in estimated blood loss, length of hospitalization, surgery-related complications, and outcome scores with an average of 8-month follow-up. Conclusions: Compared with C-ARM techniques, using navigation can eliminate RE to surgeon and decrease RE to the patient, and it had no significant effect on operating time, estimated blood loss, length of hospitalization, or perioperative complications in the patients with OLIF procedure. This study shows that navigation is a safe alternative to fluoroscopy during the OLIF procedure in the treatment of degenerative lumbar conditions.

Women fare best following surgery for degenerative lumbar spondylolisthesis: A comparison of the most and least satisfied patients utilizing data from the Quality Outcomes Database

OBJECTIVE The American Association of Neurological Surgeons launched the Quality Outcomes Database (QOD), a prospective longitudinal registry that includes demographic, clinical, and patient-reported outcome (PRO) data, to measure the safety and quality of neurosurgical procedures, including spinal surgery. Differing results from recent randomized controlled trials have established a need to clarify the groups that would most benefit from surgery for degenerative lumbar spondylolisthesis. In the present study, the authors compared patients who were the most and the least satisfied following surgery for degenerative lumbar spondylolisthesis. METHODS This was a retrospective analysis of a prospective, national longitudinal registry including patients who had undergone surgery for grade 1 degenerative lumbar spondylolisthesis. The most and least satisfied patients were identified based on an answer of 1 and 4, respectively, on the North American Spine Society (NASS) Satisfaction Questionnaire 12 months postoperatively. Baseline demographics, clinical variables, surgical parameters, and outcomes were collected. Patient-reported outcome measures, including the Numeric Rating Scale (NRS) for back pain, NRS for leg pain, Oswestry Disability Index (ODI), and EQ-5D (the EuroQol health survey), were administered at baseline and 3 and 12 months after treatment. RESULTS Four hundred seventy-seven patients underwent surgery for grade 1 degenerative lumbar spondylolisthesis in the period from July 2014 through December 2015. Two hundred fifty-five patients (53.5%) were the most satisfied and 26 (5.5%) were the least satisfied. Compared with the most satisfied patients, the least satisfied ones more often had coronary artery disease (CAD; 26.9% vs 12.2%, p = 0.04) and had higher body mass indices (32.9 ± 6.5 vs 30.0 ± 6.0 kg/m2, p = 0.02). In the multivariate analysis, female sex (OR 2.9, p = 0.02) was associated with the most satisfaction. Notably, the American Society of Anesthesiologists (ASA) class, smoking, psychiatric comorbidity, and employment status were not significantly associated with satisfaction. Although there were no significant differences at baseline, the most satisfied patients had significantly lower NRS back and leg pain and ODI scores and a greater EQ-5D score at 3 and 12 months postoperatively (p < 0.001 for all). CONCLUSIONS This study revealed that some patient factors differ between those who report the most and those who report the least satisfaction after surgery for degenerative lumbar spondylolisthesis. Patients reporting the least satisfaction tended to have CAD or were obese. Female sex was associated with the most satisfaction when adjusting for potential covariates. These findings highlight several key factors that could aid in setting expectations for outcomes following surgery for degenerative lumbar spondylolisthesis.

Back pain improves significantly following discectomy for lumbar disc herniation

BACKGROUND CONTEXTnAlthough lumbar disc herniation (LDH) classically presents with lower extremity radiculopathy, there are patients who have substantial associated back pain.nnnPURPOSEnThe present study aims to determine if patients with LDH with substantial back pain improve with decompression alone.nnnSTUDY DESIGNnThis is a longitudinal observational cohort study.nnnPATIENT SAMPLEnPatients enrolled in the Quality and Outcomes Database with LDH and a baseline back pain score of ≥5 of 10 who underwent single- or two-level lumbar discectomy only.nnnOUTCOME MEASURESnBack and leg pain scores (0-10), Oswestry Disability Index (ODI), and EuroQoL 5D were measured.nnnMETHODSnStandard demographic and surgical variables were collected, as well as patient-reported outcomes at baseline and at 3 and 12 months postoperatively.nnnRESULTSnThe mean age of the cohort was 49.8 years and 1,195 (52.8%) were male. Mean body mass index was 30.1u2009kg/m2. About half of the patients (1,103, 48.8%) underwent single-level discectomy and the other half (1,159, 51.2%) had two-level discectomy. Average blood loss was 44u2009cc. Most of the patients (2,217, 98%) were discharged home with routine postoperative care. The average length of stay was 0.53 days. At 3 and 12 months postoperatively, there were statistically significant (p<.000) improvements in back pain (from 7.7 to 2.9 to 3.2), leg pain (from 7.5 to 2.3 to 2.5), and ODI (from 26.2 to 11.6 to 11.2). Patients with a single-level discectomy, compared with patients with a two-level discectomy, had similar improvements in 3- and 12-month back pain, leg pain, and ODI scores.nnnCONCLUSIONSnPatients with LDH who have substantial back pain can be counseled to expect improvement in their back pain scores 12 months after a discectomy.

Anterior Spinal Column Augmentation Techniques

With the aging population, osteoporotic compression fractures have become increasingly common throughout the United States. Many of these patients are not suitable for open surgery, but suffer from substantial pain. It has been found that through the injection of polymethylmethacrylate cement into these fracture sites (vertebroplasty), pain can be alleviated quickly and easily with little recovery time by the patient and low rates of complications. Since the development of vertebroplasty, many other augmentation techniques, including balloon-assisted peek implant-assisted techniques, have been invented. Along with new techniques, new indications for augmentation have come about both in tumor and trauma domains. In this chapter, the expanded indications and techniques involved in vertebral augmentation will be described.