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Publication
Featured researches published by Marcus Stone.
JAMA Surgery | 2014
Jared D. Ament; Zhuo Yang; Pierce D. Nunley; Marcus Stone; Kee D. Kim
IMPORTANCE Cervical total disc replacement (CTDR) was developed to treat cervical spondylosis, while preserving motion. While anterior cervical discectomy and fusion (ACDF) has been the standard of care for 2-level disease, a randomized clinical trial (RCT) suggested similar outcomes. Cost-effectiveness of this intervention has never been elucidated. OBJECTIVE To determine the cost-effectiveness of CTDR compared with ACDF. DESIGN, SETTING, AND PARTICIPANTS Data were derived from an RCT that followed up 330 patients over 24 months. The original RCT consisted of multi-institutional data including private and academic institutions. Using linear regression for the current study, health states were constructed based on the stratification of the Neck Disability Index and a visual analog scale. Data from the 12-item Short-Form Health Survey questionnaires were transformed into utilities values using the SF-6D mapping algorithm. Costs were calculated by extracting Diagnosis-Related Group codes from institutional billing data and then applying 2012 Medicare reimbursement rates. The costs of complications and return-to-work data were also calculated. A Markov model was built to evaluate quality-adjusted life-years (QALYs) for both treatment groups. The model adopted a third-party payer perspective and applied a 3% annual discount rate. Patients included in the original RCT had to be diagnosed as having radiculopathy or myeloradiculopathy at 2 contiguous levels from C3-C7 that was unresponsive to conservative treatment for at least 6 weeks or demonstrated progressive symptoms. MAIN OUTCOMES AND MEASURES Incremental cost-effectiveness ratio of CTDR compared with ACDF. RESULTS A strong correlation (R2 = 0.6864; P < .001) was found by projecting a visual analog scale onto the Neck Disability Index. Cervical total disc replacement had an average of 1.58 QALYs after 24 months compared with 1.50 QALYs for ACDF recipients. Cervical total disc replacement was associated with
Neurosurgery | 2016
Jared D. Ament; Zhuo Yang; Pierce D. Nunley; Marcus Stone; Darrin J. Lee; Kee D. Kim
2139 greater average cost. The incremental cost-effectiveness ratio of CTDR compared with ACDF was
BioMed Research International | 2016
Pierce D. Nunley; Faheem Sandhu; Kelly Frank; Marcus Stone
24,594 per QALY at 2 years. Despite varying input parameters in the sensitivity analysis, the incremental cost-effectiveness ratio value stays below the threshold of
Neurosurgical Focus | 2018
Peter G. Campbell; Pierce D. Nunley; David A. Cavanaugh; Eubulus J. Kerr; Philip Andrew Utter; Kelly Frank; Marcus Stone
50,000 per QALY in most scenarios (range, -
The International Journal of Spine Surgery | 2018
Pierce D. Nunley; David A. Cavanaugh; Eubulus J. Kerr; Phillip Andrew Utter; Peter G. Campbell; Kelly Frank; Kyle E. Marshall; Marcus Stone
58,194 to
Neurosurgery | 2018
Pierce D. Nunley; Domagoj Coric; Kelly Frank; Marcus Stone
147,862 per QALY). CONCLUSIONS AND RELEVANCE The incremental cost-effectiveness ratio of CTDR compared with traditional ACDF is lower than the commonly accepted threshold of
Neurosurgical Focus | 2017
Pierce D. Nunley; Gregory M. Mundis; Richard G. Fessler; Paul Park; Joseph M. Zavatsky; Juan S. Uribe; Robert K. Eastlack; Dean Chou; Michael Y. Wang; Neel Anand; Kelly Frank; Marcus Stone; Adam S. Kanter; Christopher I. Shaffrey; Praveen V. Mummaneni
50,000 per QALY. This remains true with varying input parameters in a robust sensitivity analysis, reaffirming the stability of the model and the sustainability of this intervention.
The International Journal of Spine Surgery | 2016
Pierce D. Nunley; Eubulus J. Kerr; Philip Andrew Utter; David A. Cavanaugh; Kelly Frank; Devan Moody; Brian McManus; Marcus Stone
Supplemental Digital Content is Available in the Text.
Journal of Neurosurgery | 2015
Reginald J. Davis; Pierce D. Nunley; Kee D. Kim; Michael S. Hisey; Robert J. Jackson; Hyun W. Bae; Gregory Hoffman; Steven E. Gaede; Guy O. Danielson; Charles Gordon; Marcus Stone
Introduction. The lateral lumbar interbody fusion (LLIF) surgical approach has potential advantages over other approaches but is associated with some unique neurologic risks due to the proximity of the lumbosacral plexus. The present study analyzed complications following LLIF surgical approach using a novel single flat-blade retractor system. Methods. A retrospective data collection of patients receiving LLIF using a novel single flat-blade retractor system at two institutions in the US. Inclusion criteria were all patients receiving an LLIF procedure with the RAVINE® Lateral Access System (K2M, Inc., Leesburg, VA, USA). There was no restriction on preoperative diagnosis or number of levels treated. Approach-related neurologic complications were collected and analyzed postoperatively through a minimum of one year. Results. Analysis included 253 patients with one to four treated lateral levels. Immediate postoperative neurologic complications were present in 11.1% (28/253) of patients. At one-year follow-up the approach-related neurologic complications resolved in all except 5 patients (2.0%). Conclusion. We observed an 11.1% neurologic complication rate in LLIF procedures. There was resolution of symptoms for most patients by 12-month follow-up, with only 2% of patients with residual symptoms. This supports the hypothesis that the vast majority of approach-related neurologic symptoms are transient.
The Spine Journal | 2017
Pierce D. Nunley; David A. Cavanaugh; Eubulus J. Kerr; Andrew Utter; Peter G. Campbell; Kelly Frank; Marcus Stone
OBJECTIVE Recently, authors have called into question the utility and complication index of the lateral lumbar interbody fusion procedure at the L4-5 level. Furthermore, the need for direct decompression has also been debated. Here, the authors report the clinical and radiographic outcomes of transpsoas lumbar interbody fusion, relying only on indirect decompression to treat patients with neurogenic claudication secondary to Grade 1 and 2 spondylolisthesis at the L4-5 level. METHODS The authors conducted a retrospective evaluation of 18 consecutive patients with Grade 1 or 2 spondylolisthesis from a prospectively maintained database. All patients underwent a transpsoas approach, followed by posterior percutaneous instrumentation without decompression. The Oswestry Disability Index (ODI) and SF-12 were administered during the clinical evaluations. Radiographic evaluation was also performed. The mean follow-up was 6.2 months. RESULTS Fifteen patients with Grade 1 and 3 patients with Grade 2 spondylolisthesis were identified and underwent fusion at a total of 20 levels. The mean operative time was 165 minutes for the combined anterior and posterior phases of the operation. The estimated blood loss was 113 ml. The most common cage width in the anteroposterior dimension was 22 mm (78%). Anterior thigh dysesthesia was identified on detailed sensory evaluation in 6 of 18 patients (33%); all patients experienced resolution within 6 months postoperatively. No patient had lasting sensory loss or motor deficit. The average ODI score improved 26 points by the 6-month follow-up. At the 6-month follow-up, the SF-12 mean Physical and Mental Component Summary scores improved by 11.9% and 9.6%, respectively. No patient required additional decompression postoperatively. CONCLUSIONS This study offers clinical results to establish lateral lumbar interbody fusion as an effective technique for the treatment of Grade 1 or 2 degenerative spondylolisthesis at L4-5. The use of this surgical approach provides a minimally invasive solution that offers excellent arthrodesis rates as well as favorable clinical and radiological outcomes, with low rates of postoperative complications. However, adhering to the techniques of transpsoas lateral surgery, such as minimal table break, an initial look-and-see approach to the psoas, clear identification of the plexus, minimal cranial caudal expansion of the retractor, mobilization of any traversing sensory nerves, and total psoas dilation times less than 20 minutes, ensures the lowest possible complication profile for both visceral and neural injuries even in the narrow safe zones when accessing the L4-5 disc space in patients with degenerative spondylolisthesis.