Applications of SPECT/CT in the Evaluation of Spinal Pathology: A Review.

BACKGROUND: Accurate identification of pain generators in the context of low back and spine-related pain is crucial for effective treatment. This review aims to evaluate the potential usefulness of single photon emission computed tomography with computed tomography (SPECT/CT) as an imaging modality in guiding clinical decision-making. METHODS: A broad scoping literature review was conducted to identify relevant studies evaluating the use of SPECT/CT in patients with spine-related pain. Studies were reviewed for their methodology and results. RESULTS: SPECT/CT appears to have advantages over traditional modalities, such as magnetic resonance imaging and CT, in certain clinical scenarios. It may offer additional information to clinicians and improve the specificity of diagnosis. However, further studies are needed to fully assess its diagnostic accuracy and clinical utility. CONCLUSIONS: SPECT/CT is a promising imaging modality in the evaluation of low back pain, particularly in cases where magnetic resonance imaging and CT are inconclusive or equivocal. However, the current level of evidence is limited, and additional research is needed to determine its overall clinical relevance. CLINICAL RELEVANCE: SPECT/CT may have a significant impact on clinical decision-making, particularly in cases in which traditional imaging modalities fail to provide a clear diagnosis. Its ability to improve specificity could lead to more targeted and effective treatment for patients with spinal pathology.

Complications Have Not Improved With Newer Generation Robots.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The purpose of this study was to see whether upgrades in newer generation robots improve safety and clinical outcomes following spine surgery. METHODS: All patients undergoing robotic-assisted spine surgery with the Mazor X Stealth EditionTM (Medtronic, Minneapolis, MN) from 2019 to 2022 at a combined orthopedic and neurosurgical spine service were retrospectively reviewed. Robot related complications were recorded. RESULTS: 264 consecutive patients (54.1% female; age at time of surgery 63.5 ± 15.3 years) operated on by 14 surgeons were analyzed. The average number of instrumented levels with robotics was 4.2 ± 2.7, while the average number of instrumented screws with robotics was 8.3 ± 5.3. There was a nearly 50/50 split between an open and minimally invasive approach. Six patients (2.2%) had robot related complications. Three patients had temporary nerve root injuries from misplaced screws that required reoperation, one patient had a permanent motor deficit from the tap damaging the L1 and L2 nerve roots, one patient had a durotomy from a misplaced screw that required laminectomy and intra-operative repair, and one patient had a temporary sensory L5 nerve root injury from a drill. Half of these complications (3/6) were due to a reference frame error. In total, four patients (1.5%) required reoperation to fix 10 misplaced screws. CONCLUSION: Despite newer generation robots, robot related complications are not decreasing. As half the robot related complications result from reference frame errors, this is an opportunity for improvement.

A Prospective Study of Lumbar Facet Arthroplasty in the Treatment of Degenerative Spondylolisthesis and Stenosis: Results from the Total Posterior Spine System (TOPS) IDE Study.

STUDY DESIGN: Prospective randomized Food and Drug Administration investigational device exemption clinical trial. OBJECTIVE: The purpose of the present study is to report the 1-year clinical and radiographic outcomes and safety profile of patients who underwent lumbar facet arthroplasty through implantation of the Total Posterior Spine System (TOPS) device. SUMMARY OF BACKGROUND DATA: Lumbar facet arthroplasty is one proposed method of dynamic stabilization to treat grade-1 spondylolisthesis with stenosis; however, there are currently no Food and Drug Administration-approved devices for facet arthroplasty. METHODS: Standard demographic information was collected for each patient. Radiographic parameters and patient-reported outcome measures were assessed preoperatively and at regular postoperative intervals. Complication and reoperation data were also collected for each patient. RESULTS: At the time of this study, 153 patients had undergone implantation of the TOPS device. The mean surgical time was 187.8 minutes and the mean estimated blood loss was 205.7cc. The mean length of hospital stay was 3.0 days. Mean Oswestry Disability Index, Visual Analog Score leg and back, and Zurich Claudication Questionnaire scores improved significantly at all postoperative time points ( P >0.001). There were no clinically significant changes in radiographic parameters, and all operative segments remained mobile at 1-year follow-up. Postoperative complications occurred in 11 patients out of the 153 patients (7.2%) who underwent implantation of the TOPS device. Nine patients (5.9%) underwent a total of 13 reoperations, 1 (0.6%) of which was for device-related failure owing to bilateral L5 pedicle screw loosening. CONCLUSIONS: Lumbar facet arthroplasty with the TOPS device demonstrated a statistically significant improvement in all patient-reported outcome measures and the ability to maintain motion at the index level while limiting sagittal translation with a low complication rate.

Anterior Cervical Foraminotomy for Radiculopathy After Cervical Artificial Disc Replacement: Technique Description and Case Report.

BACKGROUND: Patients may occasionally have persistent or recurrent radicular symptoms after cervical artificial disc replacement (ADR) for cervical spondylotic radiculopathy. We describe our approach using anterior cervical foraminotomy (ACF) to provide symptom relief in such patients without the need to convert to a fusion or remove the ADR implant. METHODS: Our operative technique for ACF after cervical ADR begins by starting at the lateral edge of the ADR at the superior end plate of the inferior vertebral body. The ipsilateral uncovertebral joint is drilled with a combination of a high-speed burr and diamond-coated burr to minimize the risk of injury to the vertebral artery. The neuroforamen is entered after drilling through the posterior aspect of the uncinate process. The exiting cervical nerve root should be directly visualized, and a Kerrison rongeur may be used to trace along the nerve root laterally to remove any remaining uncinate osteophyte or process. We queried our internal database for patients with recurrent or new radicular pain following cervical ADR who underwent ACF. Clinical characteristics and outcomes were reported. RESULTS: Five patients with recurrent radicular symptoms after ADR were reviewed. Two ACFs were performed at C5-6, and 2 were performed at C6-7. Four patients developed ipsilateral recurrent radicular symptoms, and only 1 patient developed contralateral new radicular symptoms. Three patients reported complete resolution of their new or recurrent radicular symptoms following ACF, and 2 patients reported only partial resolution. No patients required conversion to a fusion. CONCLUSIONS: In patients with recurrent symptoms of cervical spondylotic radiculopathy following ADR, ACF with uncovertebral joint resection can be used to provide direct foraminal decompression without the need for implant removal. This approach also preserves motion at the affected level, preserves cervical spinal stability, and prevents the need for spinal fusion. CLINICAL RELEVANCE: Patients with persistent or recurrent radicular symptoms after cervical ADR may achieve resolution of symptoms through a modified ACF technique.

The Influence of Lordotic cages on creating Sagittal Balance in the CMIS treatment of Adult Spinal Deformity.

BACKGROUND: CMIS techniques are heavily dependent on placement of lateral interbody cages. Cages with an increased lordotic angle are being advocated to improve segmental lordosis and SVA. We assessed the segmental lordosis achieved with the individual cages. We further studied three variables and the effect each had on segmental lordosis: the lordosis angle of the cage, the position of the cage in the intervertebral space, and the level that it has been placed. METHODS: This is a retrospective study of 66 consecutive patients who underwent lateral interbody fusion using lordotic cages as part of CMIS correction of scoliosis from June 2012 to January 2016. Standing radiographs at pre op and 6-week follow-up were reviewed to identify the position of the cage in the intervertebral space and the amount of segmental lordosis achieved. RESULTS: A total of 224 cages were placed. The 6°, 10°, 12°, and 20° cages achieved a mean segmental lordosis of 9.00°, 13.09°, 13.23°, and 18.32°, respectively (P < .05). Additionally, cages placed in the anterior, middle, and posterior 3rd of the disk space produced 13.02°, 11.47°, and 8.23° of lordosis, respectively (P < .05). Stratifying by level, cages placed at T12-L1, L1-2, L2-3, L3-4, and L4-5 translated to mean segmental lordotic values of 8.43°, 10.02°, 11.38°, 12.91°, and 14.58°, respectively (P < .05). CONCLUSIONS: The angle of the cage had an impact on segmental lordosis. Achieved segmental lordosis was notably more when the cage was placed in lower lumbar levels. Additionally, cages placed in the posterior 3rd of the intervertebral space had significantly worse segmental lordosis compared to those placed in the anterior or middle 3rd. Our study shows that an average delta change of 8.03° can be achieved with 12° cages and this when done at each subsequent level results in a progressive harmonious creation of lordosis. IRB approval was obtained for this study.

Comparison of a Newer Versus Older Protocol for Circumferential Minimally Invasive Surgical (CMIS) Correction of Adult Spinal Deformity (ASD)-Evolution Over a 10-Year Experience.

STUDY DESIGN: Retrospective. OBJECTIVES: Compare circumferential minimally invasive surgical (CMIS) correction outcomes of patients treated for adult spinal deformity (ASD) with a newer versus older protocol SUMMARY OF BACKGROUND DATA: CMIS techniques have become increasingly popular. Increasing experience and learning curve may help improve outcomes. METHODS: A prospectively collected database was queried for all patients who underwent CMIS correction of ASD (Cobb angle >20° or sagittal vertical axis [SVA] >50 mm or pelvic incidence-lumbar lordosis mismatch >10) at 3+ levels. Those without a full-length radiograph or 2-year follow-up were excluded. Patients were compared based on treatment using our original or newer protocol. RESULTS: The original protocol had 76 patients with an average age of 66.99 years (range 46-81, standard deviation [SD] 9.03), and the new protocol had 53 patients with average age of 65.85 years (range 48-85, SD 8.08). Preoperative and latest visual analog scale (VAS) scores in the original were 6.85 and 3.45 (p = .001) and in the new were 6.19 and 2.27 (p = .004). Delta-VAS scores were 3.27 and 4.27. The Oswestry disability index (ODI) reduced from 45.84 to 32.91 (p = .041) in the original and from 44.21 to 25.39 (p = .017) in the new. Average delta-ODIs were 22.25 and 24.01. Preoperative, latest, and delta-SF physical component scores for the original were 35.38, 42.42, and 10.06 and for the new, 30.89, 39.49, and 11.93. SF mental component scores were 50.96, 55.19, and 12.84 and 50.12, 52.99, and 8.85. The original and new protocols had latest Cobb angles of 11.54° and 11.12° (p = .789), delta-Cobb angles of 14.51° and 20.03° (p < .05), latest SVAs of 42.85 and 30.58 mm (p < .05) and latest PI-LL mismatch of 15.49 and 9.00 mm (p < .05). In the original and the new, the average preoperative SVAs that reliably achieved a postoperative SVA of 50 mm or less were 84 and 119 mm, respectively, and the maximum delta-SVAs were 89 and 120 mm. The new protocol had fewer surgical complications (p < .05). CONCLUSION: Improvements in radiographic scores, functional outcomes, and limits of SVA correction and lower complication rates suggest that the new protocol may help improve outcomes. These findings may be a reflection of our 10-year experience and advances in the learning curve. LEVEL OF EVIDENCE: Level IV.

Thirty-Day Reoperation and Readmission Rates After Correction of Adult Spinal Deformity via Circumferential Minimally Invasive Surgery-Analysis of a 7-Year Experience.

STUDY DESIGN: Single-center retrospective analysis of consecutive patients who have undergone circumferential minimally invasive surgery (cMIS) for correction of adult spinal deformity (ASD). OBJECTIVES: To study the rates of reoperations and readmissions within the first 30 days following cMIS for correction of ASD. BACKGROUND: Hospital readmission and reoperation rates have been emphasized as an important measure of quality and cost-effectiveness of care. However, there is little information about the readmission rates following cMIS correction of ASD. METHODS: This is a retrospective cohort study of 214 consecutive patients with ASD who underwent correction using cMIS involving at least 2 levels. Major complications encountered during surgery or within 30 days following the index procedure that needed reoperation or readmission were recorded. The primary outcomes measured were early readmission, and early reoperation. RESULTS: An average of 4 levels were fused. Nineteen complications were noted in the 30-day period following the index surgery, giving an early complication rate of 8.9%. Twelve of those complications occurred during the initial hospitalization and 7 complications occurred after the patient had been discharged home. Forty-seven percent of the complications occurred within the first 3 years of our experience, 37% in the next 2 years, and only 16% in the following 3 years. The 30-day readmission rate was 3.3%, which showed no statistically significant difference based on the number of levels fused. CONCLUSIONS: Our study delivers significant evidence that efforts to reduce hospital readmissions for ASD patients should begin by concentrating on the postoperative complications. Although minimally invasive approaches will not eliminate all complications, they may have an effect on reducing the rate of major complications, most notably the rate of postoperative infection. This in turn can lead to a substantially lower readmission and reoperation rate as is reported in our study. LEVEL OF EVIDENCE: Level IV, case series.

Resection of spinal column tumors utilizing image-guided navigation: a multicenter analysis.

OBJECTIVE The use of intraoperative stereotactic navigation has become more available in spine surgery. The authors undertook this study to assess the utility of intraoperative CT navigation in the localization of spinal lesions and as an intraoperative tool to guide resection in patients with spinal lesions. METHODS This was a retrospective multicenter study including 50 patients from 2 different institutions who underwent biopsy and/or resection of spinal column tumors using image-guided navigation. Of the 50 cases reviewed, 4 illustrative cases are presented. In addition, the authors provide a description of surgical technique with image guidance. RESULTS The patient group included 27 male patients and 23 female patients. Their average age was 61 ± 17 years (range 14-87 years). The average operative time (incision to closure) was 311 ± 188 minutes (range 62-865 minutes). The average intraoperative blood loss was 882 ± 1194 ml (range 5-7000 ml). The average length of hospitalization was 10 ± 8.9 days (range 1-36 days). The postoperative complications included 2 deaths (4.0%) and 4 radiculopathies (8%) secondary to tumor burden. CONCLUSIONS O-arm 3D imaging with stereotactic navigation may be used to localize lesions intraoperatively with real-time dynamic feedback of tumor resection. Stereotactic guidance may augment resection or biopsy of primary and metastatic spinal tumors. It offers reduced radiation exposure to operating room personnel and the ability to use minimally invasive approaches that limit tissue injury. In addition, acquisition of intraoperative CT scans with real-time tracking allows for precise targeting of spinal lesions with minimal dissection.

Postoperative Cyst Associated with Bone Morphogenetic Protein Use in Posterior and Transforaminal Lumbar Interbody Fusion Managed Conservatively: Report of Two Cases.

Bone morphogenetic protein use in spinal surgery for off-label indications continues to remain popular. One area where its use has known associated radicular complications is posterior or transforaminal lumbar interbody fusion. These complications include radiculitis, cyst development, and heterotopic ossification, amongst others. Typically, cyst development has been treated surgically. We present two cases of bone morphogenetic protein-related cysts treated medically and thus, present medical treatment as an alternative treatment option.

Cost-effectiveness analysis in minimally invasive spine surgery.

OBJECT: Medical care has been evolving with the increased influence of a value-based health care system. As a result, more emphasis is being placed on ensuring cost-effectiveness and utility in the services provided to patients. This study looks at this development in respect to minimally invasive spine surgery (MISS) costs. METHODS: A literature review using PubMed, the Cost-Effectiveness Analysis (CEA) Registry, and the National Health Service Economic Evaluation Database (NHS EED) was performed. Papers were included in the study if they reported costs associated with minimally invasive spine surgery (MISS). If there was no mention of cost, CEA, cost-utility analysis (CUA), quality-adjusted life year (QALY), quality, or outcomes mentioned, then the article was excluded. RESULTS: Fourteen studies reporting costs associated with MISS in 12,425 patients (3675 undergoing minimally invasive procedures and 8750 undergoing open procedures) were identified through PubMed, the CEA Registry, and NHS EED. The percent cost difference between minimally invasive and open approaches ranged from 2.54% to 33.68%-all indicating cost saving with a minimally invasive surgical approach. Average length of stay (LOS) for minimally invasive surgery ranged from 0.93 days to 5.1 days compared with 1.53 days to 12 days for an open approach. All studies reporting EBL reported lower volume loss in an MISS approach (range 10-392.5 ml) than in an open approach (range 55-535.5 ml). CONCLUSIONS: There are currently an insufficient number of studies published reporting the costs of MISS. Of the studies published, none have followed a standardized method of reporting and analyzing cost data. Preliminary findings analyzing the 14 studies showed both cost saving and better outcomes in MISS compared with an open approach. However, more Level I CEA/CUA studies including cost/QALY evaluations with specifics of the techniques utilized need to be reported in a standardized manner to make more accurate conclusions on the cost effectiveness of minimally invasive spine surgery.

Limitations and ceiling effects with circumferential minimally invasive correction techniques for adult scoliosis: analysis of radiological outcomes over a 7-year experience.

OBJECT: Minimally invasive correction of adult scoliosis is a surgical method increasing in popularity. Limited data exist, however, as to how effective these methodologies are in achieving coronal plane and sagittal plane correction in addition to improving spinopelvic parameters. This study serves to quantify how much correction is possible with present circumferential minimally invasive surgical (cMIS) methods. METHODS: Ninety patients were selected from a database of 187 patients who underwent cMIS scoliosis correction. All patients had a Cobb angle greater than 15°, 3 or more levels fused, and availability of preoperative and postoperative 36-inch standing radiographs. The mean duration of follow-up was 37 months. Preoperative and postoperative Cobb angle, sagittal vertical axis (SVA), coronal balance, lumbar lordosis (LL), and pelvic incidence (PI) were measured. Scatter plots were performed comparing the pre- and postoperative radiological parameters to calculate ceiling effects for SVA correction, Cobb angle correction, and PI-LL mismatch correction. RESULTS: The mean preoperative SVA value was 60 mm (range 11.5-151 mm); the mean postoperative value was 31 mm (range 0-84 mm). The maximum SVA correction achieved with cMIS techniques in any of the cases was 89 mm. In terms of coronal Cobb angle, a mean correction of 61% was noted, with a mean preoperative value of 35.8° (range 15°-74.7°) and a mean postoperative value of 13.9° (range 0°-32.5°). A ceiling effect for Cobb angle correction was noted at 42°. The ability to correct the PI-LL mismatch to 10° was limited to cases in which the preoperative PI-LL mismatch was 38° or less. CONCLUSIONS: Circumferential MIS techniques as currently used for the treatment of adult scoliosis have limitations in terms of their ability to achieve SVA correction and lumbar lordosis. When the preoperative SVA is greater than 100 mm and a substantial amount of lumbar lordosis is needed, as determined by spinopelvic parameter calculations, surgeons should consider osteotomies or other techniques that may achieve more lordosis.

Evidence basis/outcomes in minimally invasive spinal scoliosis surgery.

Traditional adult scoliosis surgery is associated with long-term patient improvement in clinical and radiographic outcome measures, significant blood loss, and high likelihood of medical complications. Because the patient population undergoing adult scoliosis surgery is often elderly with medical comorbidities, minimally invasive spinal surgery (MISS) for adult scoliosis is theoretically appealing, because it is associated with less tissue trauma and reduced blood loss. Nevertheless, limitations exist with current techniques as far as the achievable degree of coronal and sagittal plane deformity correction. MISS scoliosis correction is reviewed, specifically regarding outcomes and complications. Limitations of current techniques and future directions are discussed.

Is circumferential minimally invasive surgery effective in the treatment of moderate adult idiopathic scoliosis?

BACKGROUND: Outcomes for minimally invasive scoliosis correction surgery have been reported for mild adult scoliosis. Larger curves historically have been treated with open surgical procedures including facet resections or posterior column osteotomies, which have been associated with high-volume blood loss. Further, minimally invasive techniques have been largely reported in the setting of degenerative scoliosis. QUESTIONS/PURPOSES: We describe the effects of circumferential minimally invasive surgery (cMIS) for moderate to severe scoliosis in terms of (1) operative time and blood loss, (2) overall health and disease-specific patient-reported outcomes, (3) deformity correction and fusion rate, and (4) frequency and types of complications. METHODS: Between January 2007 and January 2012, we performed 50 cMIS adult idiopathic scoliosis corrections in patients with a Cobb angle of greater than 30° but less than 75° who did not have prior thoracolumbar fusion surgery; this series represented all patients we treated surgically during that time meeting those indications. Our general indications for this approach during that period were increasing back pain unresponsive to nonoperative therapy with cosmetic and radiographic worsening of curves. Surgical times and estimated blood loss were recorded. Functional clinical outcomes including VAS pain score, Oswestry Disability Index (ODI), and SF-36 were recorded preoperatively and postoperatively. Patients' deformity correction was assessed on pre- and postoperative 36-inch (91-cm) standing films and fusion was assessed on CT scan. Minimum followup was 24 months (mean, 48 months; range, 24-77 months). RESULTS: Mean blood loss was 613 mL for one-stage surgery and 763 mL for two-stage surgery. Mean operative time was 351 minutes for one-stage surgery and 482 minutes for two-stage surgery. At last followup, mean VAS and ODI scores decreased from 5.7 and 44 preoperatively to 2.9 and 22 (p < 0.001 and 0.03, respectively) and mean SF-36 score increased from 48 preoperatively to 74 (p = 0.026). Mean Cobb angle and sagittal vertical axis decreased from 42° and 51 mm preoperatively to 16° and 27 mm postoperatively (both p < 0.001). An 88% fusion rate was confirmed on CT scan. Perioperative complications occurred in 11 of the 50 patients (22%), with delayed complications needing further surgery in 10 more patients at last followup. CONCLUSIONS: cMIS provides for good clinical and radiographic outcomes for moderate (30°-75°) adult idiopathic scoliosis. Patients undergoing cMIS should be carefully selected to avoid fixed, rigid deformities and a preoperative sagittal vertical axis of greater than 10 cm; surgeons should consider alternative techniques in those patients. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Does minimally invasive transsacral fixation provide anterior column support in adult scoliosis?

BACKGROUND: Spinal fusion to the sacrum, especially in the setting of deformity and long constructs, is associated with high complication and pseudarthrosis rates. Transsacral discectomy, fusion, and fixation is a minimally invasive spine surgery technique that provides very rigid fixation. To date, this has been minimally studied in the setting of spinal deformity correction. QUESTIONS/PURPOSES: We determined (1) the fusion rate of long-segment arthrodeses, (2) heath-related quality-of-life (HRQOL) outcomes (VAS pain score, Oswestry Disability Index [ODI], SF-36), and (3) the common complications and their frequency in adult patients with scoliosis undergoing transsacral fixation without supplemental pelvic fixation. METHODS: Between April 2007 and May 2011, 92 patients had fusion of three or more segments extending to the sacrum for spinal deformity. Transsacral L5-S1 fusion without supplemental pelvic fixation was performed in 56 patients. Of these, 46 with complete data points and a minimum of 2 years of followup (mean, 48 months; range, 24-72 months; 18% of patients lost to followup) were included in this study. Nineteen of the 46 (41%) had fusions extending above the thoracolumbar junction, with one patient having fusion into the proximal thoracic spine (T3-S1). General indications for the use of transsacral fixation were situations where the fusion needed to be extended to the sacrum, such as spondylolisthesis, prior laminectomy, stenosis, oblique take-off, and disc degeneration at L5-S1. Contraindications included anatomic variations in the sacrum, vascular anomalies, prior intrapelvic surgery, and rectal fistulas or abscesses. Fusion rates were assessed by full-length radiographs and CT scanning. HRQOL data, including VAS pain score, ODI, and SF-36 scores, were assessed at all pre- and postoperative visits. Intraoperative and postoperative complications were noted. RESULTS: Forty-one of 46 patients (89%) developed a solid fusion at L5-S1. There were significant improvements in all HRQOL parameters. Eight patients had complications related to the transsacral fusion, including five pseudarthroses and three superficial wound dehiscences. Three patients underwent revision surgery with iliac fixation. There were no bowel injuries, sacral hematomas, or sacral fractures. CONCLUSIONS: Transsacral fixation/fusion may allow for safe lumbosacral fusion without iliac fixation in the setting of long-segment constructs in carefully selected patients. This study was retrospective and suffered from some loss to followup; future prospective trials are called for to compare this technique to other, more established approaches. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Long-term 2- to 5-year clinical and functional outcomes of minimally invasive surgery for adult scoliosis.

STUDY DESIGN: A retrospective study. OBJECTIVE: We assess MIS technique's clinical and functional outcomes during a 2- to 5-year period. SUMMARY OF BACKGROUND DATA: Traditional surgical approaches for adult scoliosis are associated with significant blood loss and morbidity, in a population that is often elderly with multiple medical comorbidities. Minimally invasive surgery (MIS) represents a newer method of achieving similar long-term outcomes but considerably lower morbidity and complication rates. METHODS: We reviewed 71 patients who underwent MIS correction of spinal deformity with fusion of 2 or more levels including: degenerative scoliosis (54), idiopathic scoliosis (11), and iatrogenic scoliosis (6). All underwent a combination of 3 MIS techniques: direct lateral interbody fusion (66), axial lumbar interbody fusion (34), and posterior instrumentation (67). Thirty-six patients were staged with direct lateral interbody fusion done first followed by the posterior instrumentation and fusion including axial lumbar interbody fusion done 3 days later. RESULTS: Mean age was 64 years (20-84 yr). Mean follow-up was 39 months (24-60 mo). Patients with 1-stage same-day surgery had a mean blood loss of 412 mL and a mean surgical time of 291 minutes. Patients with 2-stage surgery had a mean blood loss of 314 mL and surgical time of 183 minutes for direct lateral interbody fusion and 357 mL and 243 minutes, respectively for posterior instrumentation and axial lumbar interbody fusion. Mean hospital stay was 7.6 days (2-26 d). The mean preoperative Cobb angle was 24.7° (8.3°-65°), which corrected to 9.5° (0.6°-28.8°). Mean preoperative Coronal balance was 25.5 mm, which corrected to 11 mm. Mean preoperative sagittal balance was 31.7 mm and corrected to 10.7 mm. The mean preoperative lumbar apical vertebral translation was 24 mm and corrected to 12 mm. Fourteen patients had adverse events requiring intervention: 4 pseudarthrosis, 4 persistent stenosis, 1 osteomyelitis, 1 adjacent segment discitis, 1 late wound infection, 1 proximal junctional kyphosis, 1 screw prominence, 1 idiopathic cerebellar hemorrhage, and 2 wound dehiscence. CONCLUSION: A combination of 3 novel MIS techniques allows comparable correction of adult spinal deformity, with low pseudarthrosis rates, significantly improved functional outcomes, and excellent clinical and radiological improvement, but considerably lowers morbidity and complication rates at early and long-term follow-up.

Surgical management of primary spinal hemangiopericytomas: an institutional case series and review of the literature.

PURPOSE: Hemangiopericytoma (HPC) is a rare tumor of the central nervous system. Primary spinal occurrence of this tumor is extremely uncommon and cases involving the intramedullary spinal cord are even more rare. The purpose of this study was to explore the clinical features, surgical strategies, outcome and pathology in a consecutive series of patients treated at a single institution. METHODS: The authors performed a retrospective review of the clinicopathological characteristics of four patients with a pathological diagnosis of spinal HPC. RESULTS: Four cases with intradural as well as intra/extra-medullary components were identified. Gross total resection with no recurrence at the operative site was achieved in the majority of patients with a spinal HPC. One patient had significant recurrence and eventually, succumbed to the disease. CONCLUSION: Increased awareness of these tumors' capability to occur intradurally and intramedullarly can help surgeons accurately diagnose and choose an effective plan of care. Gross total resection of hemangiopericytomas is the mainstay of treatment and should be pursued if feasible. Histopathology is essential to the diagnosis.

Minimally invasive approaches for the correction of adult spinal deformity.

INTRODUCTION: Spinal deformity surgery is historically associated with significant blood loss and medical complications. Minimally invasive deformity correction is a promising approach to spinal deformity surgery where deformity correction and fusion can be achieved with less tissue trauma, reduced blood loss and potentially less complications. MATERIALS AND METHODS: We discuss technical aspects of minimally invasive deformity correction, review the transpsoas and presacral approaches for discectomy and fusion, and review multilevel posterior percutaneous pedicle instrumentation and rod placement for deformity correction. We also review our results using these techniques and review the literature regarding outcomes in this emerging area of spinal surgery. CONCLUSIONS: Minimally invasive deformity correction is a promising method of spinal deformity correction. Early clinical results are similar to open techniques, with reduced blood loss and less complications than traditional approaches. Meticulous technique and careful patient selection are required for good results and to avoid complications.

Extrusion of expandable stacked interbody device for lumbar fusion: case report of a complication.

STUDY DESIGN: A case report. OBJECTIVE: We report on the device failure of a polyetherether-ketone expandable cage device with posterior migration of one of its components. SUMMARY OF BACKGROUND DATA: Posterior migration of transforaminal lumbar interbody fusion cage devices has been reported with static devices, and ours is the first report of an expandable TLIF device failure and posterior migration of one of its components. METHODS: The patient is a 30-year-old man who had previously failed 3 lumbar surgical procedures and presented for L5-S1 lumbar fusion with pedicle screws and transforaminal interbody fusion. RESULTS: Postoperative imaging demonstrated posterior migration of one of the failed expandable interbody components with eventual revision surgery and placement of static transforaminal lumbar interbody fusion cages. CONCLUSION: This is the first case report to describe such complication, and caution must be warranted when using these devices.

Role of dynesys as pedicle-based nonfusion stabilization for degenerative disc disorders.

Posterior nonfusion pedicle-screw-based stabilization remains a controversial area of spine surgery. To date, the Dynesys system remains the most widely implanted posterior nonfusion pedicle screw system. We review the history of Dynesys and discuss clinical outcome studies and biomechanical evaluations regarding the Dynesys system. Indications for surgery and controversies are discussed. Recommendations are made regarding technical implantation.