Transpars approach for L5-S1 foraminal and extra-foraminal lumbar disc herniations: technical note.

BACKGROUND: The short pars and the narrowed surgical corridor for far lateral L5S1 herniation make the transpars approach challenging. The aim of this study is to determine the feasibility, efficacy, and safety of the transpars microscopic approach for the treatment of L5-S1 foraminal and extraforaminal lumbar disc herniation. METHODS: From 2015 to 2019, patients with L5-S1 far lateral lumbar disc herniation were prospectively recruited. Drug intake, working days lost, NRS-leg, NRS-back, nerve-root palsy, Oswestry disability-index, Macnab criteria were recorded before surgery and at follow-up. Patients were seen at 1-6-12 months after surgery. Lumbar dynamic X-rays were performed at 6-12 months after surgery and again at 2-4 years after surgery. Key-steps of surgery are described. RESULTS: Fourteen patients were enrolled. NRS-leg and NRS-back scores significantly improved (from 7.93 to 1.43 and from 3.2 to 0.6, respectively; P<0.0001). Oswestry Score significantly decreased (from 63.14 to 19.36 at 12 months; P<0.0001). L5 Root palsy improved in all cases (from 3.72/5 to 5/5; P<0.0001). At 12-months, excellent or good outcome (Macnab criteria) was achieved in 12 (85.7%) and 2 (14.3%) patients, respectively. All patients who were not retired returned to work within 30 days after surgery. No recurrence, instability or re-operations occurred. CONCLUSIONS: The trans pars microscopic approach is feasible, safe, and effective for L5-S1 foraminal and extraforaminal disc herniation. During surgery, the key-point is the oblique working angle, directed caudally, parallel to L5 pedicle. The iliac crest does not seem to constitute an obstacle.

Evolution of Complex Spine Surgery in Neurosurgery: From Big to Minimally Invasive Surgery for the Treatment of Spinal Deformity.

Spinal instrumentation for adult spinal deformity dates back to the surgical correction of secondary complications from infectious processes, such as Pott's disease and poliomyelitis [1]. With the population aging at a longer life expectancy today, advanced degenerative spinal diseases and idiopathic scoliosis supersede as the most common causes of adult spinal deformity. Correction of the thoracolumbar malignment, specifically, has rapidly evolved with the burgeoning success of spinal instrumentation. The objective of this chapter is to review the metamorphosis of operative principles for adult thoracolumbar deformity, from aggressive osteotomies in the posterior bony elements to minimally invasive surgery (MIS) at the intervertebral disc space.

Occipital condyle screws: indications and technique.

Occipitocervical instability is a life threatening and disabling disorder caused by a myriad of pathologies. Restoring the anatomical integrity and stability of the occipitocervical junction (OCJ) is essential to achieve optimal clinical outcomes. Surgical stabilization of the OCJ is challenging and technically demanding. There is a paucity of options available for anchorage in the cephalad part of the construct in occipitocervical fixation systems due to the intricate topography of the craniocervical junction combined with the risk of injury to the surrounding anatomical structures. Surgical techniques and instrumentation for stabilizing the unstable OCJ have undergone several modifications over the years and have primarily depended on occipital squama-based fixations. At present, the occipital-plate-screw-rod construct is the most commonly adopted technique of stabilizing the OCJ. In certain distinct scenarios like posterior fossa craniectomy (absence of occipital squama for screw placement), malignancy and infection of occipital squama (poor screw purchase in the diseased occipital bone) and in revision surgery for failed occipitocervical stabilization, occipital plate-based instrumentation is not feasible. To overcome these difficulties, recently, a novel technique of occipitocervical stabilization, using the occipital condyle (OC) as the cephalad anchor, namely the direct occipital condyle screw (OCS) fixation was described. Several cadaveric and biomechanical studies have suggested that OCSs are feasible options as additional augmentative anchors in a standard occipital plate-screw-rod construct or as salvage cephalad anchors in previous failed occipital-plate-screw-rod constructs. The OCS placement technique has a steep learning curve. We have done a review of the techniques of OCS fixation and have described the indications, biomechanical and technical considerations, preoperative planning, surgical technique, complications, advantages and limitations of OCS based occipitocervical fixation.

Treatment of the Fractional Curve of Adult Scoliosis With Circumferential Minimally Invasive Surgery Versus Traditional, Open Surgery: An Analysis of Surgical Outcomes.

STUDY DESIGN: Retrospective, multicenter review of adult scoliosis patients with minimum 2-year follow-up. OBJECTIVE: Because the fractional curve (FC) of adult scoliosis can cause radiculopathy, we evaluated patients treated with either circumferential minimally invasive surgery (cMIS) or open surgery. METHODS: A multicenter retrospective adult deformity review was performed. Patients included: age >18 years with FC >10°, ≥3 levels of instrumentation, 2-year follow-up, and one of the following: coronal Cobb angle (CCA) > 20°, pelvic incidence and lumbar lordosis (PI-LL) > 10°, pelvic tilt (PT) > 20°, and sagittal vertical axis (SVA) > 5 cm. RESULTS: The FC was treated in 118 patients, 79 open and 39 cMIS. The FCs had similar coronal Cobb angles preoperative (17° cMIS, 19.6° open) and postoperative (7° cMIS, 8.1° open), but open had more levels treated (12.1 vs 5.7). cMIS patients had greater reduction in VAS leg (6.4 to 1.8) than open (4.3 to 2.5). With propensity matching 40 patients for levels treated (cMIS: 6.6 levels, N = 20; open: 7.3 levels, N = 20), both groups had similar FC correction (18° in both preoperative, 6.9° in cMIS and 8.5° postoperative). Open had more posterior decompressions (80% vs 22.2%, P < .001). Both groups had similar preoperative (Visual Analogue Scale [VAS] leg 6.1 cMIS and 5.4 open) and postoperative (VAS leg 1.6 cMIS and 3.1 open) leg pain. All cMIS patients had interbody grafts; 35% of open did. There was no difference in change of primary CCA, PI-LL, LL, Oswestry Disability Index, or VAS Back. CONCLUSION: Patients' FCs treated with cMIS had comparable reduction of leg pain compared with those treated with open surgery, despite significantly fewer cMIS patients undergoing direct decompression.

Home Versus Rehabilitation: Factors that Influence Disposition After Minimally Invasive Surgery in Adult Spinal Deformity Surgery.

BACKGROUND: Minimally invasive surgery (MIS) correction for adult spinal deformity (ASD) may reduce the need the need for postoperative skilled nursing facility (SNF) or inpatient rehabilitation (IR) placement following surgery. The likelihood of requiring placement in a facility rather than home disposition may be influenced by various factors. In addition, the associations between discharge location and outcomes and complication rates have not been elucidated in these patients. In this study, we aimed to define factors predicting disposition to an SNF/IR and to elucidate the rates of complications occurring in patients sent to home versus to a facility. METHODS: A retrospective review of a multicenter ASD database, which included patients who underwent surgery between 2009 and 2014. Inclusion criteria were age >18 years, MIS as part of index surgery, location of discharge, and at least 1 of the following: pelvic tilt >20°, sagittal vertical axis >5 cm, pelvic incidence-lumbar lordosis mismatch >10, or lumbar scoliosis >20°. Patients with a 2-year follow-up were included. Preoperative demographic and radiographic data, postoperative (<30 day) complications, and health-related quality of life were analyzed. RESULTS: A total of 182 patients met our inclusion criteria, including 113 who were discharged to home and 69 who were discharged to an SNF/IR. Older patients (>50 years) were more likely to be discharged to an SNF/IR (P = 0.043). Those aged >70 years were 6-fold more likely to go to an SNF/IR. No association was identified between discharge to an SNF/IR and any radiographic parameters except preoperative pelvic tilt (odds ratio [OR], 1.11; P = 0.009). Staged cases were more likely to be discharged to an SNF/IR (OR, 3.24; 95% confidence interval, 1.11-9.46; P = 0.032); otherwise, there was no difference in levels treated, operating time, estimated blood loss, osteotomy, or length of hospital stay. Patients requiring discharge to an SNF/IR had a higher rate of complications (58% vs. 39.8%; P = 0.017), including major complications (19.5% vs. 42%; P = 0.001), perioperative complications (14.2% vs. 31.9%; P = 0.004) and infections (3.5% vs. 13%; P = 0.016). Patients discharged to an SNF/IR had a higher rate of revision (19.5% vs. 33%; P = 0.035). Health-related quality of life measures were similar regardless of disposition. CONCLUSIONS: Older patients and those undergoing staged MIS deformity correction have a higher likelihood of postoperative disposition to an SNF/IR. Complications occurred more commonly in those patients requiring transfer to an SNF/IR after hospitalization.

Patients with High Pelvic Tilt Achieve the Same Clinical Success as Those with Low Pelvic Tilt After Minimally Invasive Adult Deformity Surgery.

BACKGROUND: Pelvic tilt (PT) is a compensatory mechanism for adult spinal deformity patients to mitigate sagittal imbalance. The association between preop PT and postop clinical and radiographic outcomes has not been well studied in patients undergoing minimally invasive adult deformity surgery. OBJECTIVE: To evaluate clinical and radiographic outcomes in adult spinal deformity patients with high and low preoperative PT treated surgically using less invasive techniques. METHODS: Retrospective case-control, institutional review board-approved study. A multicenter, minimally invasive surgery spinal deformity patient database was queried for 2-yr follow-up with complete radiographic and health-related quality of life (HRQOL) data. Hybrid surgery patients were excluded. Inclusion criteria were as follows: age > 18 and either coronal Cobb angle > 20, sagittal vertical axis > 5 cm, pelvic incidence-lumbar lordosis (PI-LL) > 10 or PT > 20. Patients were stratified by preop PT as per Schwab classification: low (PT< 20), mid (PT 20-30), or high (>30). Postoperative radiographic alignment parameters (PT, PI, LL, Cobb angle, sagittal vertical axis) and HRQOL data (Visual Analog Scale Back/Leg, Oswestry Disability Index) were evaluated and analyzed. RESULTS: One hundred sixty-five patients had complete 2-yr outcomes data, and 64 patients met inclusion criteria (25 low, 21 mid, 18 high PT). High PT group had higher preop PI-LL mismatch (32.1 vs 4.7; P < .001). At last follow-up, 76.5% of patients in the high PT group had continued PI-LL mismatch compared to 34.8% in the low PT group (P < .006). There was a difference between groups in terms of postop changes of PT (-3.9 vs 1.9), LL (8.7 vs 0.5), and PI-LL (-9.5 vs 0.1). Postoperatively, HRQOL data (Oswestry Disability Index and Visual Analog Scale) were significantly improved in both groups (P < .001). CONCLUSION: Adult deformity patients with high preoperative PT treated with minimally invasive surgical techniques had less radiographic success but equivalent clinical outcomes as patients with low PT.

Radiosurgery for Treatment of Renal Cell Metastases to Spine: A Systematic Review of the Literature.

BACKGROUND: The incidence of renal cell carcinoma (RCC) continues to increase, and the spine is the most common site for bony metastasis. Radiation therapy is one treatment for spinal RCC metastasis. Stereotactic body radiotherapy (SBRT) is a newer treatment that reportedly has benefits over conventional external beam radiotherapy. This study systematically reviewed the current literature on SBRT for metastatic RCC to spine. METHODS: A search of PubMed, Embase, and Scopus databases was conducted in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Clinical articles evaluating SBRT for RCC metastases were identified. After inclusion and exclusion criteria were applied, the search resulted in 9 articles. Data including pain outcomes, local control, survival outcomes, vertebral compression fracture (VCF), and toxicity were extracted and evaluated. RESULTS: The studies analyzed showed an improvement in pain in 41%-95% of patients. Local control rates after SBRT ranged 71.2%-85.7% at 1 year, a significant improvement when compared with conventional external beam radiotherapy. The rate of VCF after treatment with SBRT ranged 16%-27.5%, with single-fraction therapy being a risk factor for increased incidence. Overall toxicity rates ranged 23%-38.5%, with only 3 cases of grade 3 toxicity (nausea) and no cases of radiation myelitis. CONCLUSIONS: Use of SBRT for spinal metastasis from RCC resulted in significant local control and pain outcomes. There is a risk of VCF with SBRT; however, treatment seems to be well tolerated with few serious side effects. There is continued need for long-term prospective studies investigating the optimal role of SBRT in the treatment algorithm of RCC spinal metastases.

Complication rates associated with open versus percutaneous pedicle screw instrumentation among patients undergoing minimally invasive interbody fusion for adult spinal deformity.

OBJECTIVE High-quality studies that compare outcomes of open and minimally invasively placed pedicle screws for adult spinal deformity are needed. Therefore, the authors compared differences in complications from a circumferential minimally invasive spine (MIS) surgery and those from a hybrid surgery. METHODS A retrospective review of a multicenter database of patients with spinal deformity who were treated with an MIS surgery was performed. Database inclusion criteria included an age of ≥ 18 years and at least 1 of the following: a coronal Cobb angle of > 20°, a sagittal vertical axis of > 5 cm, a pelvic incidence-lumbar lordosis angle of > 10°, and/or a pelvic tilt of > 20°. Patients were propensity matched according to the levels instrumented. RESULTS In this database, a complete data set was available for 165 patients, and after those who underwent 3-column osteotomy were excluded, 137 patients were available for analysis; 76 patients remained after propensity matching (MIS surgery group 38 patients, hybrid surgery group 38 patients). The authors found no difference in demographics, number of levels instrumented, or preoperative and postoperative radiographic results. At least 1 complication was suffered by 55.3% of patients in the hybrid surgery group and 44.7% of those in the MIS surgery group (p = 0.359). Patients in the MIS surgery group had significantly fewer neurological, operative, and minor complications than those in the hybrid surgery group. The reoperation rates in both groups were similar. The most common complication category for the MIS surgery group was radiographic and for the hybrid surgery group was neurological. Patients in both groups experienced postoperative improvement in their Oswestry Disability Index and visual analog scale (VAS) back and leg pain scores (all p < 0.05); however, MIS surgery provided a greater reduction in leg pain according to VAS scores. CONCLUSIONS Overall complication rates in the MIS and hybrid surgery groups were similar. MIS surgery resulted in significantly fewer neurological, operative, and minor complications. Reoperation rates in the 2 groups were similar, and despite complications, the patients reported significant improvement in their pain and function.

Utility of the Surgical Apgar Score for Patients Who Undergo Surgery for Spinal Metastasis.

STUDY DESIGN: Retrospective review of patients who underwent surgery for spinal metastasis between 2005 and 2011. OBJECTIVE: To assess the utility of the surgical Apgar score (SAS) in patients who underwent surgery for spinal metastasis. SUMMARY OF BACKGROUND DATA: Surgery for spinal metastasis can be associated with relatively high morbidity and mortality. Consequently, identifying patients at risk for major postoperative complications is important. Several studies have validated SAS for predicting 30-day complication risk. METHODS: SASs were calculated and patients stratified into 5 groups: scores 0-2, 3-4, 5-6, 7-8, 9-10 points. Multivariate logistic regression assessed whether SAS was an independent predictor of major complication 30 days after surgery. Multivariate analysis of covariance assessed whether SAS was independently associated with length of stay. RESULTS: Ninety-seven patients with a variety of metastatic tumors were analyzed. There was no obvious trend in complication rates, or significant association between SAS and complication rate (P=0.413). Complication rates were 25.0% for SASs 0-2, 33.3% for 3-4, 18.4% for 5-6, 10.0% for 7-8, and 33.3% for 9-10 points. On multivariate analysis, SAS was not independently associated with complications; age above 65 years (odds ratio 4.19; 95% confidence interval, 1.31-52.27; P=0.028) and preoperative Karnofsky Performance Score of 10-40 (odds ratio 9.13; 95% confidence interval, 1.42-58.63; P=0.020) were associated with higher odds of complication. SASs 0-2 were an independent predictor of longer hospital stay (P=0.004). CONCLUSIONS: Our findings suggest that SAS is not a significant predictor of major perioperative complications after spinal metastasis surgery; preoperative functional status and age are stronger predictors. The need continues for a preoperative scoring system to reliably predict risk for perioperative complications after spinal metastasis surgery.

Biomechanical Investigation of a Novel Revision Device in an Osteoporotic Model: Pullout Strength of Pedicle Screw Anchor Versus Larger Screw Diameter.

STUDY DESIGN: In vitro cadaveric biomechanical study. OBJECTIVE: To assess revision pullout strength of novel anchored screws (AS) versus conventional larger diameter traditional pedicle screws (TPS) in an osteoporotic model. SUMMARY OF BACKGROUND DATA: Pedicle screws are the most ubiquitous method of treating spinal pathologies requiring lumbar fusion. Although these screws are effective in providing 3-column stabilization of the spine, revision surgeries are occasionally necessary, particularly for geriatric and osteoporotic populations. Innovative technologies should be tested to ensure continued improvement in revision techniques. METHODS: For 4 specimens at L2-L5 (T-score=-3.6±0.54), 6.5-mm-diameter TPS were inserted into left and right pedicles and were pulled out; revision screws were then inserted. Polyether-ether-ketone anchors, designed to expand around a 6.5-mm screw, were inserted into all left pedicles. On the contralateral side, 7.5-mm-diameter TPS were inserted at L2-L3, and 8.5-mm-diameter TPS at L4-L5. Pullout testing was performed at 10 mm/min. The maximum pullout strength and insertion forces were recorded. RESULTS: The initial average pullout force (6.5-mm screw) was 837 N (±329 N) and 642 N (±318 N) in L2-L3 and L4-L5 left pedicles, and 705 N (±451 N) and 779 N (±378 N) in L2-L3 and L4-L5 right pedicles, respectively. Comparison of revision pullout forces versus initial pullout forces revealed the following: 87% and 63% for AS in L2-L3 and L4-L5 left pedicles, respectively; 56% for 7.5-mm and 93% for 8.5-mm TPS in L2-L3 and L4-L5 right pedicles, respectively. CONCLUSIONS: Anchor sleeves with 6.5-mm-diameter pedicle screws provided markedly higher resistance to screw pullout than 7.5-mm-diameter revision screws and fixation statistically equivalent to 8.5-mm-diameter screws, possibly because of medial-lateral expansion within the vertebral space and/or convex filling of the pedicle. AS results had the lowest SD, indicating minimal variability in bone-screw purchase.

Does clinical improvement of symptomatic degenerative lumbar disease impact obesity?

OBJECTIVE Obesity and low-back pain associated with degenerative spondylosis or spondylolisthesis are common comorbid conditions. Many patients report that the pain and disability associated with degenerative lumbar disease are key factors in their inability to lose weight. The aim of this retrospective study was to determine if there is an association between improved functional status and weight loss following a successful transforaminal lumbar interbody fusion (TLIF) procedure. METHODS A retrospective cohort study of patients who underwent single-level TLIF was performed. Inclusion criteria were preoperative body mass index (BMI) greater than 30 kg/m2, achievement of minimum clinically important difference in the Oswestry Disability Index (ODI, defined as improvement of 15 points), and minimum 1-year postoperative followup BMI. Preoperative and postoperative BMI, ODI, and visual analog scale (VAS) scores were compared. A subgroup analysis of patients who achieved substantial clinical benefit (SCB, defined as a net improvement of 18.8 points on the ODI) was also performed. RESULTS A total of 56 patients met the inclusion criteria. The mean age of the study population was 55.6 ± 13.7 years. The mean preoperative BMI was 34.8 ± 4.6 kg/m2, the mean preoperative ODI was 66.2 ± 10.1, and the mean preoperative VAS score was 7.1 ± 1.7. The mean change in ODI was -33.1 ± 13.5 (p < 0.01) and the mean change in the VAS score was -4.1 ± 2.1 (p < 0.01). The mean change in BMI was +0.15 ± 2.1 kg/m2 (range -4.2 to +6.5 kg/m2; p = 0.6). SCB was achieved in 46 patients on the ODI. The mean preoperative BMI for patients with SCB was 34.8 ± 4.8 kg/m2, and the mean postoperative BMI was 34.7 ± 5.0 kg/m2. The mean change in BMI was -0.03 ± 1.9 kg/m2 (p = 0.9). CONCLUSIONS Despite successful surgical intervention via TLIF with achievement of improved function and pain, obese patients did not have significant change in weight postoperatively.

Postoperative dysphagia correlates with increased morbidity, mortality, and costs in anterior cervical fusion.

Anterior cervical fusion (ACF) after discectomy and/or corpectomy is a common procedure with traditionally good patient outcomes. Though typically mild, postoperative dysphagia can result in significant patient morbidity. In this study, we examine the relationship between postoperative dysphagia and in-hospital outcomes, readmissions, and overall costs. The University HealthSystem Consortium (UHC) database was utilized to perform a retrospective cohort study of all adults who underwent a principal procedure of ACF of the anterior column (International Classification of Diseases, Ninth Revision [ICD-9] procedure code 81.02) between 2013 and 2015. Patients with a diagnosis of dysphagia (ICD-9 78720-78729) were compared to those without. Patient demographics, length of stay, in-hospital mortality, 30-day readmissions, and direct costs were recorded. A total of 49,300 patients who underwent ACF were identified. Mean age was 54.5years and 50.2% were male. Dysphagia was documented in 3,137 patients (6.4%) during their hospital stay. Patients with dysphagia had an average 2.1 comorbidities, while patients without dysphagia had 1.5 (p<0.01). Mean length of stay was 6.38days in patients with dysphagia, and 2.13days in those without (p<0.01). In-hospital mortality was 0.10% in patients without dysphagia, and 0.61% in those with dysphagia (p<0.01). Direct costs were $13,099 in patients without dysphagia, and $21,245 in those with dysphagia (p<0.01). Thirty-day readmission rate was 2.9% in patients without dysphagia, and 5.3% in those with dysphagia (p=0.01). In summary, dysphagia in patients who undergo ACF correlates with significantly increased length of stay, 30-day readmissions, and in-hospital mortality. Direct costs are similarly increased as a result.

Clinical and radiographic parameters associated with best versus worst clinical outcomes in minimally invasive spinal deformity surgery.

OBJECTIVE Minimally invasive surgery (MIS) techniques are increasingly used to treat adult spinal deformity. However, standard minimally invasive spinal deformity techniques have a more limited ability to restore sagittal balance and match the pelvic incidence-lumbar lordosis (PI-LL) than traditional open surgery. This study sought to compare "best" versus "worst" outcomes of MIS to identify variables that may predispose patients to postoperative success. METHODS A retrospective review of minimally invasive spinal deformity surgery cases was performed to identify parameters in the 20% of patients who had the greatest improvement in Oswestry Disability Index (ODI) scores versus those in the 20% of patients who had the least improvement in ODI scores at 2 years' follow-up. RESULTS One hundred four patients met the inclusion criteria, and the top 20% of patients in terms of ODI improvement at 2 years (best group, 22 patients) were compared with the bottom 20% (worst group, 21 patients). There were no statistically significant differences in age, body mass index, pre- and postoperative Cobb angles, pelvic tilt, pelvic incidence, levels fused, operating room time, and blood loss between the best and worst groups. However, the mean preoperative ODI score was significantly higher (worse disability) at baseline in the group that had the greatest improvement in ODI score (58.2 vs 39.7, p < 0.001). There was no difference in preoperative PI-LL mismatch (12.8° best vs 19.5° worst, p = 0.298). The best group had significantly less postoperative sagittal vertical axis (SVA; 3.4 vs 6.9 cm, p = 0.043) and postoperative PI-LL mismatch (10.4° vs 19.4°, p = 0.027) than the worst group. The best group also had better postoperative visual analog scale back and leg pain scores (p = 0.001 and p = 0.046, respectively). CONCLUSIONS The authors recommend that spinal deformity surgeons using MIS techniques focus on correcting a patient's PI-LL mismatch to within 10° and restoring SVA to < 5 cm. Restoration of these parameters seems to impact which patients will attain the greatest degree of improvement in ODI outcomes, while the spines of patients who do the worst are not appropriately corrected and may be fused into a fixed sagittal plane deformity.

Neurosurgery and Telemedicine in the United States: Assessment of the Risks and Opportunities.

BACKGROUND: Telemedicine has seen substantial growth in the past 20 years, related to technologic advancements and evolving reimbursement policies. The risks and opportunities of neurosurgical telemedicine are nuanced. METHODS: We reviewed general and peer-reviewed literature as it relates to telemedicine and neurosurgery, with particular attention to best practices, relevant state and federal policy conditions, economic evaluations, and prospective clinical studies. RESULTS: Despite technologic development, growing interest, and increasing reimbursement opportunities, telemedicine's utilization remains limited because of concerns regarding an apparent lack of need for telemedicine services, lack of widespread reimbursement, lack of interstate licensure reciprocity, lack of universal access to necessary technology, concerns about maintaining patient confidentiality, and concerns and limited precedent regarding liability issues. The Veterans Health Administration, a component of the U.S. Department of Veterans Affairs, represents a setting in which these concerns can be largely obviated and is a model for telemedicine best practices. Results from the VA demonstrate substantial cost savings and patient satisfaction with remote care for chronic neurologic conditions. Overall, the economic and clinical benefits of telemedicine will likely come from 1) diminished travel times and lost work time for patients; 2) remote consultation of subspecialty experts, such as neurosurgeons; and 3) remote consultation to assist with triage and care in time-sensitive scenarios, including acute stroke care and "teletrauma." CONCLUSIONS: Telemedicine is effective in many health care scenarios and will become more relevant to neurosurgical patient care. We favor proceeding with legislation to reduce barriers to telemedicine's growth.

Reoperation rates in minimally invasive, hybrid and open surgical treatment for adult spinal deformity with minimum 2-year follow-up.

INTRODUCTION: Minimally invasive surgical (MIS) techniques are gaining popularity in the treatment of adult spinal deformity (ASD). The premise is that MIS techniques will lead to equivalent outcomes and a reduction in perioperative complications when compared with open techniques. Potential issues with MIS techniques are a limited capacity to correct lumbar lordosis, unknown long-term efficacy, and the potential need for revision surgery. This study compares reoperation rates and reasons for reoperation following MIS, hybrid, and open surgery for ASD through multicenter database analysis. METHODS: We retrospectively analyzed a prospective multicenter ASD database comparing open and MIS correction techniques. Inclusion criteria were: age > 18 years with minimum 20° coronal lumbar Cobb angle, a minimum of three levels fused, and minimum 2-year follow-up. Patients were propensity matched for preoperative sagittal vertebral axis (SVA), pelvic incidence-lumbar lordosis (PI-LL), and number of levels fused. We included 189 patients from three propensity-matched subgroups of 63 patients each: (1) MIS: lateral or transforaminal lumbar interbody fusion (LIF) and percutaneous pedicle instrumentation, (2) Hybrid: MIS LIF with open posterior segmental fixation (PSF), and (3) OPEN: open posterior fixation ± osteotomies. RESULTS: With propensity matching, there were significant differences between groups in pre-op SVA or PI-LL (p > 0.05). The MIS group had significantly fewer levels fused (5.4) (0-14) than the OPEN group (7.4) (p = 0.002) (0-17). The rate of revision surgery was significantly different between the groups with a higher rate of revision (27 %) amongst the HYB group versus MIS = 11.1 %, and OPEN = 12.0 %. The most common reason for reoperation in the OPEN and HYB groups was a postoperative neurological deficit (7.9 and 11.1 %), respectively. The most common reason for reoperation in the MIS group was pseudoarthrosis (7.9 %). CONCLUSIONS: Reoperation rates were not statistically different among the MIS, and OPEN surgical groups, but differed significantly on multivariate analysis with HYB group. The incidence of reoperations was twice as high in the Hybrid group compared to OPEN and MIS.

Comparison of Complications and Clinical and Radiographic Outcomes Between Nonobese and Obese Patients with Adult Spinal Deformity Undergoing Minimally Invasive Surgery.

OBJECTIVE: Obesity can be associated with increased complications and potentially worse outcomes. We aimed to evaluate the impact of obesity on complications and outcomes in patients with adult spinal deformity (ASD) who underwent minimally invasive surgery (MIS). METHODS: A multicenter database of patients with ASD treated via MIS was queried. Of 190 patients in the database, 77 fit the inclusion criteria of 3 or more spinal levels treated minimally invasively. Patients were divided by body mass index (BMI) <30 (nonobese; n = 59) and BMI ≥ 30 (obese; n = 18). RESULTS: Mean BMI was 24.6 nonobese and 35.0 obese (P < 0.001). There were mean 3.8 interbody fusions nonobese and 4.7 obese (P = 0.065). Levels treated posteriorly averaged 5.8 nonobese and 5.9 obese (P = 0.502). Mean follow-up was 34.4 months nonobese and 35.3 months obese (P = 0.976). Baseline radiographic parameters were similar between groups. Postoperatively, SVA averaged 83.9 mm obese and 20.4 mm nonobese (P = 0.002). Postoperative lumbar lordosis-pelvic incidence mismatch averaged 17.9° obese and 9.9° nonobese (P = 0.028). Both groups had improvement in Oswestry Disability Index (ODI) scores with no difference in postoperative ODI scores between groups (P = 0.090). Similarly, both groups had decreased VAS scores for back and leg pain with no difference between groups postoperatively. Twenty (33.9%) nonobese patients versus 7 (38.9%) obese patients had complications (P = 0.452). CONCLUSIONS: Our results suggest that obesity does not negatively impact complication rate or clinical outcomes in patients with ASD treated via MIS approaches.

Can a Minimal Clinically Important Difference Be Achieved in Elderly Patients with Adult Spinal Deformity Who Undergo Minimally Invasive Spinal Surgery?

BACKGROUND: Older age has been considered a relative contraindication to complex spinal procedures. Minimally invasive surgery (MIS) techniques to treat patients with adult spinal deformity (ASD) have emerged with the potential benefit of decreased approach-related morbidity. OBJECTIVE: To determine whether a minimal clinically important difference (MCID) could be achieved in patients ages ≥ 65 years with ASD who underwent MIS. METHODS: Multicenter database of patients who underwent MIS for ASD was queried. Outcome metrics assessed were Oswestry Disability Index (ODI) and visual analog scale (VAS) scores for back and leg pain. On the basis of published reports, MCID was defined as a positive change of 12.8 ODI, 1.2 VAS back pain, and 1.6 VAS leg pain. RESULTS: Forty-two patients were identified. Mean age was 70.3 years; 31 (73.8%) were women. Preoperatively, mean coronal curve, pelvic tilt, pelvic incidence to lumbar lordosis mismatch, and sagittal vertical axis were 35°, 24.6°, 14.2°, and 4.7 cm, respectively. Postoperatively, mean coronal curve, pelvic tilt, pelvic incidence to lumbar lordosis, and sagittal vertical axis were 18°, 25.4°, 11.9°, and 4.9 cm, respectively. A mean of 5.0 levels was treated posteriorly, and a mean of 4.0 interbody fusions was performed. Mean ODI improved from 47.1 to 25.1. Mean VAS back and leg pain scores improved from 6.8 and 5.9 to 2.7 and 2.7, respectively. Mean follow-up was 32.1 months. For ODI, 64.3% of patients achieved MCID. For VAS back and leg pain, 82.9% and 72.2%, respectively, reached MCID. CONCLUSIONS: MCID represents the threshold at which patients feel a meaningful clinical improvement has occurred. Our study results suggest that the majority of elderly patients with modest ASD can achieve MCID with MIS.

Comparison of complication rates of minimally invasive transforaminal lumbar interbody fusion and lateral lumbar interbody fusion: a systematic review of the literature.

OBJECT Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) and lateral lumbar interbody fusion (LLIF) are 2 currently popular techniques for lumbar arthrodesis. The authors compare the total risk of each procedure, along with other important complication outcomes. METHODS This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Relevant studies (up to May 2015) that reported complications of either MI-TLIF or LLIF were identified from a search in the PubMed database. The primary outcome was overall risk of complication per patient. Secondary outcomes included risks of sensory deficits, temporary neurological deficit, permanent neurological deficit, intraoperative complications, medical complications, wound complications, hardware failure, subsidence, and reoperation. RESULTS Fifty-four studies were included for analysis of MI-TLIF, and 42 studies were included for analysis of LLIF. Overall, there were 9714 patients (5454 in the MI-TLIF group and 4260 in the LLIF group) with 13,230 levels fused (6040 in the MI-TLIF group and 7190 in the LLIF group). A total of 1045 complications in the MI-TLIF group and 1339 complications in the LLIF group were reported. The total complication rate per patient was 19.2% in the MI-TLIF group and 31.4% in the LLIF group (p < 0.0001). The rate of sensory deficits and temporary neurological deficits, and permanent neurological deficits was 20.16%, 2.22%, and 1.01% for MI-TLIF versus 27.08%, 9.40%, and 2.46% for LLIF, respectively (p < 0.0001, p < 0.0001, p = 0.002, respectively). Rates of intraoperative and wound complications were 3.57% and 1.63% for MI-TLIF compared with 1.93% and 0.80% for LLIF, respectively (p = 0.0003 and p = 0.034, respectively). No significant differences were noted for medical complications or reoperation. CONCLUSIONS While there was a higher overall complication rate with LLIF, MI-TLIF and LLIF both have acceptable complication profiles. LLIF had higher rates of sensory as well as temporary and permanent neurological symptoms, although rates of intraoperative and wound complications were less than MI-TLIF. Larger, prospective comparative studies are needed to confirm these findings as the current literature is of relative poor quality.

Comparison of two minimally invasive surgery strategies to treat adult spinal deformity.

OBJECT: Minimally invasive surgery (MIS) techniques are becoming a more common means of treating adult spinal deformity (ASD). The aim of this study was to compare the hybrid (HYB) surgical approach, involving minimally invasive lateral interbody fusion with open posterior instrumented fusion, to the circumferential MIS (cMIS) approach to treat ASD. METHODS: The authors performed a retrospective, multicenter study utilizing data collected in 105 patients with ASD who were treated via MIS techniques. Criteria for inclusion were age older than 45 years, coronal Cobb angle greater than 20°, and a minimum of 1 year of follow-up. Patients were stratified into 2 groups: HYB (n = 62) and cMIS (n = 43). RESULTS: The mean age was 60.7 years in the HYB group and 61.0 years in the cMIS group (p = 0.910). A mean of 3.6 interbody fusions were performed in the HYB group compared with a mean of 4.0 interbody fusions in the cMIS group (p = 0.086). Posterior fusion involved a mean of 6.9 levels in the HYB group and a mean of 5.1 levels in the cMIS group (p = 0.003). The mean follow-up was 31.3 months for the HYB group and 38.3 months for the cMIS group. The mean Oswestry Disability Index (ODI) score improved by 30.6 and 25.7, and the mean visual analog scale (VAS) scores for back/leg pain improved by 2.4/2.5 and 3.8/4.2 for the HYB and cMIS groups, respectively. There was no significant difference between groups with regard to ODI or VAS scores. For the HYB group, the lumbar coronal Cobb angle decreased by 13.5°, lumbar lordosis (LL) increased by 8.2°, sagittal vertical axis (SVA) decreased by 2.2 mm, and LL-pelvic incidence (LL-PI) mismatch decreased by 8.6°. For the cMIS group, the lumbar coronal Cobb angle decreased by 10.3°, LL improved by 3.0°, SVA increased by 2.1 mm, and LL-PI decreased by 2.2°. There were no significant differences in these radiographic parameters between groups. The complication rate, however, was higher in the HYB group (55%) than in the cMIS group (33%) (p = 0.024). CONCLUSIONS: Both HYB and cMIS approaches resulted in clinical improvement, as evidenced by decreased ODI and VAS pain scores. While there was no significant difference in degree of radiographic correction between groups, the HYB group had greater absolute improvement in degree of lumbar coronal Cobb angle correction, increased LL, decreased SVA, and decreased LL-PI. The complication rate, however, was higher with the HYB approach than with the cMIS approach.

BMP-2 inhibits tumor-initiating ability in human renal cancer stem cells and induces bone formation.

PURPOSE: We have previously shown that BMP-2 induces bone formation and inhibits tumorigenicity of cancer stem cells (CSCs) in a human osteosarcoma OS99-1 cell line. In this study, we sought to determine whether BMP-2 can similarly induce bone formation and inhibit the tumorigenicity of renal CSCs identified based on aldehyde dehydrogenase (ALDH) activity in renal cell carcinoma (RCC) cell lines and primary tumors. METHODS: Using a xenograft model in which cells from human RCC cell lines ACHN, Caki-2, and primary tumors were grown in NOD/SCID mice, renal CSCs were identified as a subset of ALDH(br) cells. The ALDH(br) cells possessed a greater colony-forming efficiency, higher proliferative output, increased expression of stem cell marker genes Oct3/4A, Nanog, renal embryonic marker Pax-2, and greater tumorigenicity compared to cells with low ALDH activity (ALDH(lo) cells), generating new tumors with as few as 25 cells in mice. RESULTS: In vitro, BMP-2 was found to inhibit the ALDH(br) cell growth, down-regulate the expression of embryonic stem cell markers, and up-regulate the transcription of osteogenic markers. In vivo, all animals receiving a low number of ALDH(br) cells (5 × 10(3)) from ACHN, Caki-2, and primary tumor xenografts treated with 30 µg BMP-2 per animal showed limited tumor growth with significant bone formation, while untreated cells developed large tumor masses without bone formation. CONCLUSIONS: These results suggest that BMP-2 inhibits the tumor-initiating ability of renal CSCs and induces osseous bone formation. BMP-2 may therefore provide a beneficial strategy for human RCC treatment by targeting the CSC-enriched population.