Meic H. Schmidt, Frederick A. Boop, Neil A. Martin, and Jonathan R. Slotkin
Jonathan R. Slotkin, Alfred S. Casale, Glenn D. Steele Jr., and Steven A. Toms
Comparative effectiveness research (CER) represents an evolution in clinical decision-making research that allows for the study of heterogeneous groups of patients with complex diseases processes. It has foundations in decision science, reliability science, and health care policy research. Health care finance will increasingly rely on CER for guidance in the coming years. There is increasing awareness of the importance of decreasing unwarranted variation in health care delivery. In the past 7 years, Geisinger Health System has performed broad reengineering of its acute episodic and chronic care delivery models utilizing macrosystem-level application of CER principles. These provider-driven process initiatives have resulted in significant improvement across all segments of care delivery, improved patient outcomes, and notable cost containment. These programs have led to the creation of novel pricing models, and when “hardwired” throughout a care delivery system, they can lead to correct medical decision making by 100% of providers in all patient encounters. Neurosurgery as a specialty faces unique challenges and opportunities with respect to broad adoption and application of CER techniques.
Case report and review of the literature
Patrick J. Codd, Ron I. Riesenburger, Paul Klimo Jr., Jonathan R. Slotkin, and Edward R. Smith
✓ Aneurysmal bone cysts (ABCs) are benign, highly vascular osseous lesions characterized by cystic, blood-filled spaces surrounded by thin perimeters of expanded bone. Children and young adults are most often affected by spinal ABCs; more than 75% of patients are younger than 20 years old at presentation. Although ABCs have been documented in all areas of the axial and appendicular skeleton, ABCs of the spine present unique challenges due to the risk of vertebral destabilization, pathological fracture and vertebral body (VB) collapse, and neurological compromise. The authors describe the case of an 8-year-old child who presented with low-back pain and was subsequently found to have a lumbar ABC causing vertebra plana of the L-3 VB. They also review the literature on ABCs of the spine. This case highlights the importance of considering an ABC in the differential diagnosis when vertebra plana is seen in pediatric patients.
Kevin T. Foley, Eric J. Woodard, Jonathan R. Slotkin, Cassandra K. Mayotte, Abigail C. Baldwin, Michael C. Brown, and Brian J. Hess
The authors’ goal in this study was to investigate the use of a novel, bioresorbable, osteoconductive, wet-field mineral-organic bone adhesive composed of tetracalcium phosphate and phosphoserine (TTCP-PS) for cranial bone flap fixation and compare it with conventional low-profile titanium plates and self-drilling screws.
An ovine craniotomy surgical model was used to evaluate the safety and efficacy of TTCP-PS over 2 years. Bilateral cranial defects were created in 41 sheep and were replaced in their original position. The gaps (kerfs) were completely filled with TTCP-PS (T1 group), half-filled with TTCP-PS (T2 group), or left empty and the flaps fixated by plates and screws as a control (C group). At 12 weeks, 1 year, and 2 years following surgery, the extent of bone healing, local tissue effects, and remodeling of the TTCP-PS were analyzed using macroscopic observations and histopathological and histomorphometric analyses. Flap fixation strength was evaluated by biomechanical testing at 12 weeks and 1 year postoperatively.
No adverse local tissue effects were observed in any group. At 12 weeks, the bone flap fixation strengths in test group 1 (1689 ± 574 N) and test group 2 (1611 ± 501 N) were both statistically greater (p = 0.01) than that in the control group (663 ± 385 N). From 12 weeks to 1 year, the bone flap fixation strengths increased significantly (p < 0.05) for all groups. At 1 year, the flap fixation strength in test group 1 (3240 ± 423 N) and test group 2 (3212 ± 662 N) were both statistically greater (p = 0.04 and p = 0.02, respectively) than that in the control group (2418 ± 1463 N); however, there was no statistically significant difference in the strengths when comparing the test groups at both timepoints. Test group 1 had the best overall performance based on histomorphometric evaluation and biomechanical testing. At 2 years postoperatively, the kerfs filled with TTCP-PS had histological evidence of osteoconduction and replacement of TTCP-PS by bone with nearly complete osteointegration.
TTCP-PS was demonstrated to be safe and effective for cranial flap fixation in an ovine model. In this study, the bioresorbable, osteoconductive bone adhesive appeared to have multiple advantages over standard plate-and-screw bone flap fixation, including biomechanical superiority, more complete and faster bony healing across the flap kerfs without fibrosis, and the minimization of bone flap and/or hardware migration and loosening. These properties of TTCP-PS may improve human cranial bone flap fixation and cranioplasty.
Anthony L. Asher, Panagiotis Kerezoudis, Praveen V. Mummaneni, Erica F. Bisson, Steven D. Glassman, Kevin T. Foley, Jonathan R. Slotkin, Eric A. Potts, Mark E. Shaffrey, Christopher I. Shaffrey, Domagoj Coric, John J. Knightly, Paul Park, Kai-Ming Fu, Clinton J. Devin, Kristin R. Archer, Silky Chotai, Andrew K. Chan, Michael S. Virk, and Mohamad Bydon
Patient-reported outcomes (PROs) play a pivotal role in defining the value of surgical interventions for spinal disease. The concept of minimum clinically important difference (MCID) is considered the new standard for determining the effectiveness of a given treatment and describing patient satisfaction in response to that treatment. The purpose of this study was to determine the MCID associated with surgical treatment for degenerative lumbar spondylolisthesis.
The authors queried the Quality Outcomes Database registry from July 2014 through December 2015 for patients who underwent posterior lumbar surgery for grade I degenerative spondylolisthesis. Recorded PROs included scores on the Oswestry Disability Index (ODI), EQ-5D, and numeric rating scale (NRS) for leg pain (NRS-LP) and back pain (NRS-BP). Anchor-based (using the North American Spine Society satisfaction scale) and distribution-based (half a standard deviation, small Cohen’s effect size, standard error of measurement, and minimum detectable change [MDC]) methods were used to calculate the MCID for each PRO.
A total of 441 patients (80 who underwent laminectomies alone and 361 who underwent fusion procedures) from 11 participating sites were included in the analysis. The changes in functional outcome scores between baseline and the 1-year postoperative evaluation were as follows: 23.5 ± 17.4 points for ODI, 0.24 ± 0.23 for EQ-5D, 4.1 ± 3.5 for NRS-LP, and 3.7 ± 3.2 for NRS-BP. The different calculation methods generated a range of MCID values for each PRO: 3.3–26.5 points for ODI, 0.04–0.3 points for EQ-5D, 0.6–4.5 points for NRS-LP, and 0.5–4.2 points for NRS-BP. The MDC approach appeared to be the most appropriate for calculating MCID because it provided a threshold greater than the measurement error and was closest to the average change difference between the satisfied and not-satisfied patients. On subgroup analysis, the MCID thresholds for laminectomy-alone patients were comparable to those for the patients who underwent arthrodesis as well as for the entire cohort.
The MCID for PROs was highly variable depending on the calculation technique. The MDC seems to be a statistically and clinically sound method for defining the appropriate MCID value for patients with grade I degenerative lumbar spondylolisthesis. Based on this method, the MCID values are 14.3 points for ODI, 0.2 points for EQ-5D, 1.7 points for NRS-LP, and 1.6 points for NRS-BP.
Anthony L. Asher, John Knightly, Praveen V. Mummaneni, Mohammed Ali Alvi, Matthew J. McGirt, Yagiz U. Yolcu, Andrew K. Chan, Steven D. Glassman, Kevin T. Foley, Jonathan R. Slotkin, Eric A. Potts, Mark E. Shaffrey, Christopher I. Shaffrey, Regis W. Haid Jr., Kai-Ming Fu, Michael Y. Wang, Paul Park, Erica F. Bisson, Robert E. Harbaugh, and Mohamad Bydon
The Quality Outcomes Database (QOD), formerly known as the National Neurosurgery Quality Outcomes Database (N2QOD), was established by the NeuroPoint Alliance (NPA) in collaboration with relevant national stakeholders and experts. The overarching goal of this project was to develop a centralized, nationally coordinated effort to allow individual surgeons and practice groups to collect, measure, and analyze practice patterns and neurosurgical outcomes. Specific objectives of this registry program were as follows: “1) to establish risk-adjusted national benchmarks for both the safety and effectiveness of neurosurgical procedures, 2) to allow practice groups and hospitals to analyze their individual morbidity and clinical outcomes in real time, 3) to generate both quality and efficiency data to support claims made to public and private payers and objectively demonstrate the value of care to other stakeholders, 4) to demonstrate the comparative effectiveness of neurosurgical and spine procedures, 5) to develop sophisticated ‘risk models’ to determine which subpopulations of patients are most likely to benefit from specific surgical interventions, and 6) to facilitate essential multicenter trials and other cooperative clinical studies.” The NPA has launched several neurosurgical specialty modules in the QOD program in the 7 years since its inception including lumbar spine, cervical spine, and spinal deformity and cerebrovascular and intracranial tumor. The QOD Spine modules, which are the primary subject of this paper, have evolved into the largest North American spine registries yet created and have resulted in unprecedented cooperative activities within our specialty and among affiliated spine care practitioners. Herein, the authors discuss the experience of QOD Spine programs to date, with a brief description of their inception, some of the key achievements and milestones, as well as the recent transition of the spine modules to the American Spine Registry (ASR), a collaboration between the American Association of Neurological Surgeons and the American Academy of Orthopaedic Surgeons (AAOS).
Praveen V. Mummaneni, Erica F. Bisson, Panagiotis Kerezoudis, Steven Glassman, Kevin Foley, Jonathan R. Slotkin, Eric Potts, Mark Shaffrey, Christopher I. Shaffrey, Domagoj Coric, John Knightly, Paul Park, Kai-Ming Fu, Clinton J. Devin, Silky Chotai, Andrew K. Chan, Michael Virk, Anthony L. Asher, and Mohamad Bydon
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.
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.
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.
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.
Erica F. Bisson, Praveen V. Mummaneni, Michael S. Virk, John Knightly, Mohammed Ali Alvi, Anshit Goyal, Andrew K. Chan, Jian Guan, Steven Glassman, Kevin Foley, Jonathan R. Slotkin, Eric A. Potts, Mark E. Shaffrey, Christopher I. Shaffrey, Regis W. Haid Jr., Kai-Ming Fu, Michael Y. Wang, Paul Park, Anthony L. Asher, and Mohamad Bydon
Lumbar decompression without arthrodesis remains a potential treatment option for cases of low-grade spondylolisthesis (i.e., Meyerding grade I). Minimally invasive surgery (MIS) techniques have recently been increasingly used because of their touted benefits including lower operating time, blood loss, and length of stay. Herein, the authors analyzed patients enrolled in a national surgical registry and compared the baseline characteristics and postoperative clinical and patient-reported outcomes (PROs) between patients undergoing open versus MIS lumbar decompression.
The authors queried the Quality Outcomes Database for patients with grade I lumbar degenerative spondylolisthesis undergoing a surgical intervention between July 2014 and June 2016. Among more than 200 participating sites, the 12 with the highest enrollment of patients into the lumbar spine module came together to initiate a focused project to assess the impact of fusion on PROs in patients undergoing surgery for grade I lumbar spondylolisthesis. For the current study, only patients in this cohort from the 12 highest-enrolling sites who underwent a decompression alone were evaluated and classified as open or MIS (tubular decompression). Outcomes of interest included PROs at 2 years; perioperative outcomes such as blood loss and complications; and postoperative outcomes such as length of stay, discharge disposition, and reoperations.
A total of 140 patients undergoing decompression were selected, of whom 71 (50.7%) underwent MIS and 69 (49.3%) underwent an open decompression. On univariate analysis, the authors observed no significant differences between the 2 groups in terms of PROs at 2-year follow-up, including back pain, leg pain, Oswestry Disability Index score, EQ-5D score, and patient satisfaction. On multivariable analysis, compared to MIS, open decompression was associated with higher satisfaction (OR 7.5, 95% CI 2.41–23.2, p = 0.0005). Patients undergoing MIS decompression had a significantly shorter length of stay compared to the open group (0.68 days [SD 1.18] vs 1.83 days [SD 1.618], p < 0.001).
In this multiinstitutional prospective study, the authors found comparable PROs as well as clinical outcomes at 2 years between groups of patients undergoing open or MIS decompression for low-grade spondylolisthesis.
Praveen V. Mummaneni, Mohamad Bydon, John J. Knightly, Mohammed Ali Alvi, Yagiz U. Yolcu, Andrew K. Chan, Kevin T. Foley, Jonathan R. Slotkin, Eric A. Potts, Mark E. Shaffrey, Christopher I. Shaffrey, Kai-Ming Fu, Michael Y. Wang, Paul Park, Cheerag D. Upadhyaya, Anthony L. Asher, Luis Tumialan, and Erica F. Bisson
Optimizing patient discharge after surgery has been shown to impact patient recovery and hospital/physician workflow and to reduce healthcare costs. In the current study, the authors sought to identify risk factors for nonroutine discharge after surgery for cervical myelopathy by using a national spine registry.
The Quality Outcomes Database cervical module was queried for patients who had undergone surgery for cervical myelopathy between 2016 and 2018. Nonroutine discharge was defined as discharge to postacute care (rehabilitation), nonacute care, or another acute care hospital. A multivariable logistic regression predictive model was created using an array of demographic, clinical, operative, and patient-reported outcome characteristics.
Of the 1114 patients identified, 11.2% (n = 125) had a nonroutine discharge. On univariate analysis, patients with a nonroutine discharge were more likely to be older (age ≥ 65 years, 70.4% vs 35.8%, p < 0.001), African American (24.8% vs 13.9%, p = 0.007), and on Medicare (75.2% vs 35.1%, p < 0.001). Among the patients younger than 65 years of age, those who had a nonroutine discharge were more likely to be unemployed (70.3% vs 36.9%, p < 0.001). Overall, patients with a nonroutine discharge were more likely to present with a motor deficit (73.6% vs 58.7%, p = 0.001) and more likely to have nonindependent ambulation (50.4% vs 14.0%, p < 0.001) at presentation. On multivariable logistic regression, factors associated with higher odds of a nonroutine discharge included African American race (vs White, OR 2.76, 95% CI 1.38–5.51, p = 0.004), Medicare coverage (vs private insurance, OR 2.14, 95% CI 1.00–4.65, p = 0.04), nonindependent ambulation at presentation (OR 2.17, 95% CI 1.17–4.02, p = 0.01), baseline modified Japanese Orthopaedic Association severe myelopathy score (0–11 vs moderate 12–14, OR 2, 95% CI 1.07–3.73, p = 0.01), and posterior surgical approach (OR 11.6, 95% CI 2.12–48, p = 0.004). Factors associated with lower odds of a nonroutine discharge included fewer operated levels (1 vs 2–3 levels, OR 0.3, 95% CI 0.1–0.96, p = 0.009) and a higher quality of life at baseline (EQ-5D score, OR 0.43, 95% CI 0.25–0.73, p = 0.001). On predictor importance analysis, baseline quality of life (EQ-5D score) was identified as the most important predictor (Wald χ2 = 9.8, p = 0.001) of a nonroutine discharge; however, after grouping variables into distinct categories, socioeconomic and demographic characteristics (age, race, gender, insurance status, employment status) were identified as the most significant drivers of nonroutine discharge (28.4% of total predictor importance).
The study results indicate that socioeconomic and demographic characteristics including age, race, gender, insurance, and employment may be the most significant drivers of a nonroutine discharge after surgery for cervical myelopathy.