Meet Our Medical Staff

Minimally Invasive
Spine Institute

300 Exempla Circle
Suite #130
Lafayette, CO 80026

Ph: (303) 539-2533


Jennifer Kenitzer

Clinical Director:
Joe Young, RN

Our Physicians
G. Arends, M.D.
A. Mason, M.D.
S. Rajpal, M.D.
E. L. Nelson, M.D.
C. Van Buskirk, M.D.
A. Villavicencio, M.D.
K. Beasley, DO, MBe

Click on a link below to go the the Physicians' web site

Boulder Neurosurgical Associates

Ph: (303) 938-5700

• Dr. Alan Villavicencio
• Dr. E. Lee Nelson
• Dr. Alexander Mason
• Dr. Sharad Rajpal
• Dr. Kara Beasley, DO, MBe

Alpine Spine Center

Ph: (303) 546-6600

• Dr. Cathleen Van Buskirk

Colorado Center for
Spine Medicine


Ph: (303) 444-2955

• Dr. Gregory Arends

Our Physicians
Alan Thomas Villavicencio, M.D. received his medical degree from Harvard in 1995 and went on to complete a neurosurgical residency at Duke University Medical Center in 2001. He then finished an orthopedic spine surgery fellowship at Cedars-Sinai Medical Center in Los Angeles in 2002 and is one of only a handful of surgeons in the country with dual neurosurgery and orthopedic spine training.

He is board certified and the senior practicing partner in Boulder Neurosurgical Associates, a group of private practice neurosurgeons in Colorado. He specializes in complex spinal reconstructive surgery including scoliosis and other types of deformity as well as minimally invasive spine surgery. He treats almost all types of brain and spinal disorders, performing approximately 500 operative cases annually.

Dr. Villavicencio is the Founder and current Program Chairman for an annual regional neurosurgical symposium entitled Current Techniques in the Treatment of Cranial and Spinal Disorders. This symposium is currently in it’s 6th year and draws approximately 200 physicians and allied health care providers each year. Dr. Villavicencio is also the Founder and Chairman of the Board for the Justin Parker Neurological Institute, a tax-exempt 501 (c)(3) nonprofit organization with an approximate annual budget of $250,000 whose principle purpose is to conduct clinical research and to disseminate this and other information to patients and the medical community.

Dr. Villavicencio's goal as a neurosurgeon is not just to stay at the forefront of neurosurgical care but to actually advance the field through the continued development and application of new and innovative surgical and non-surgical treatment options. He is one of the few neurosurgeons in the country dedicated to improving clinical outcomes and patient safety by promoting and implementing evidence-based medicine into clinical practice.

Dr. Villavicencio is Director of Research and Development for Boulder Neurosurgical Associates in addition to being the senior managing partner. He is also Director of Neurosurgery at Boulder Community and Longmont United Hospitals and Director of Surgery at the Minimally Invasive Spine Institute in Colorado. Dr. Villavicencio has presented hundreds of abstracts at national and international neurosurgical meetings and has published more than 60 peer-reviewed articles and book chapters in leading neurosurgical journals and textbooks. He is also principle investigator for several ongoing FDA IDE (investigational device exemption) prospective randomized trials.

Dr. Villavicencio is a member of the American Association of Neurological Surgeons (AANS), The Congress of Neurological Surgeons (CNS), The North American Spine Society (NASS), The Colorado Neurosurgical Society (CNS), The Colorado Medical Society (CMS) and the AANS/CNS Section on Disorders of the Spine and Peripheral Nerves and the Section on Tumors.

Dr. Villavicencio is a devoted husband and father of two children, including a 3 year-old boy and a 2 year-old girl. He also operates a small organic farm in his free time with about 30 head of cattle, 75 chickens and 5 pigs. He is an avid athlete and runs a sub 3 hour marathon. He has competed in 32 marathons, 28 triathlons and 14 full Ironman events, including the Ironman World Championships in Kona, Hawaii on several occasions.

As such, he has a particular interest in treating athletes and all other patients with the goal of utilizing less invasive techniques for a faster recovery back to peak physical condition.

Cathleen S. Van Buskirk, M.D. of Alpine Spine, is board-certified by the American Board of Orthopaedic Surgery and the American Board of Spine Surgery.

Dr. Van Buskirk graduated from medical school at the Medical College of Wisconsin. She performed her internship and residency in Orthopedic Surgery at the University of New Mexico, where she was awarded Outstanding Resident Publication for Lumbosacral and Sacropelvic Fixation.

Dr. Van Buskirk performed two fellowships – her first fellowship was in Spine Surgery at Thomas Jefferson University in Philadelphia, Pennsylvania. She performed her second fellowship in Pediatric Orthopedic Spine Surgery in Paris, France, at St. Vincent De Paul Hospital.

Dr. Van Buskirk has been published in teaching books such as Surgical Approaches to the Spine and Contemporary Management of Spinal Cord Injury. She is also a member of the Scoliosis Research Society, the North American Spine Society, the American Academy of Orthopaedic Surgeons and the American Association of Orthopaedic Surgeons.

• Click to read article - 10 Female Spine Surgeons to Know
Gregory Arends, M.D. founded the Colorado Center for Spine Medicine in 2010, and is a founding member of the Minimally Invasive Spine Institute in Lafayette, CO.  Dr. Arends is a fully board-certified and fellowship-trained physician with expertise in the diagnosis and treatment of pain of spinal origin.  He treats occupational and sports related injuries, joint, nerve, and musculoskeletal conditions.

Boarded in Physical Medicine and Rehabilitation and specializing in interventional spinal procedures, Dr. Arends is an active lecturer and physician educator speaking and instructing both locally and nationally on the topics of minimally-invasive spinal interventions, injections, and rehabilitative spine care.  He continues to better his field with research and the publishing of scientific articles and textbook chapters.

Dr. Arends is fellowship-trained in interventional procedures including fluoroscopically-guided spinal and peripheral joint injections, minimally-invasive spinal interventions such as radiofrequency neurotomy, intradiscal electrothermal annuloplasty (IDET), and percutaneous discectomies.  He performs interventional diagnostic testing such as discography and selective spinal blocks, as well as electrodiagnostic testing.  He employs a wide range of cutting-edge medical and rehabilitative techniques to reduce pain and promote the long-term healing of his patients.

Dr. Arends earned his medical degree in 1995 from Wayne State University School of Medicine in Detroit, Michigan.  After receiving his degree, Dr. Arends held an internship in Internal Medicine at Northwestern Memorial Hospital / Northwestern University Feinberg School of Medicine and a residency in Physical Medicine and Rehabilitation at the Rehabilitation Institute of Chicago.  Following the completion of his residency in 1999, Dr. Arends continued his specialty training with a fellowship in Interventional Spine and Pain Management at Georgia Pain Physicians in Atlanta, GA. 

Dr. Arends began practice in Chicago at the prestigious Chicago Institute of Neurosurgery and Neuroresearch where he helped found CINN’s Institute for Spine Care.

Dr. Arends moved to Boulder, CO in 2003 working at Boulder Neurosurgical Associates where he helped establish the Boulder Back Institute.

Dr. Arends has worked with the FBI’s Hostage Rescue Team, and currently is a team member of the Denver Bureau’s Special Weapons and Tactics team providing training and operational tactical emergency medicine support, and spine/musculoskeletal care consulting.
E. Lee Nelson, M.D. specializes in the treatment of cranial and spinal disorders with the emphasis on minimally invasive techniques.

He completed his residency at Baylor College of Medicine in Houston in one of the largest and busiest training programs in the country where he received extensive training in the management of both degenerative and oncologic diseases of the spine. 

He spent additional time focusing on spinal oncology under the direction of the renowned spine surgeon Dr. Ziya Gokaslan at the renowned MD Anderson Cancer Center. 

He has practiced locally in the Boulder area since 2004 and continues to focus on delivering state of the art care to his patients.  He is actively involved in education of both the community and other spine surgeons from around the country who travel to the area to hear him speak about image guided spine surgery and minimally invasive techniques.

Alexander Mason, M.D. received his Bachelor’s degree in Microbiology at Miami University in Oxford, Ohio and his M.D. from Ohio State University College of Medicine and Public Health.

He completed his neurosurgical residency at the Cleveland Clinic Foundation in Cleveland, Ohio with interests in complex and minimally invasive spine, neuro-oncology and surgical epilepsy.

During his residency, he was awarded the Charles Plante Public Policy Fellowship and spent a year in Washington D.C. working in neurosurgical and medical public policy on Capital Hill.  After residency, he completed a formal fellowship in Cerebrovascular and Skull Base surgery at Emory University
in Atlanta. 

Dr. Mason works with the Boulder Neurosurgical Associates specializing in the comprehensive treatment of spine and intracranial neurosurgical diseases and disorders.

Sharad Rajpal, M.D. received his Medical Degree from the University of Wisconsin, where he continued his training and residency in Neurological Surgery. After residency, Dr. Rajpal completed a combined Neurosurgical and Orthopedic Spine Surgery Fellowship at Cleveland Clinic Hospital, where he gained specialty training in the latest techniques in treating spinal tumors, minimally invasive surgery and complex spinal deformity.

In addition to being one of the few spine surgeons in the country with dual neurosurgical and orthopedic spine training, Dr. Rajpal has also done extensive research and published more than 30 peer-reviewed papers and book chapters.

Dr. Rajpal’s clinical interests include conditions of the cervical, thoracic and lumbar spine, as well as general neurosurgical conditions, including neuro-oncology, neuro-endoscopy and intra-operative neuro-navigation.

Dr. Rajpal’s goal is to provide personalized, high quality medical care to his patients.
Dr. Kara Beasley, DO, MBe
Movement Disorder Neurosurgeon

Dr. Beasley completed her undergraduate degree at the University of North Carolina. She then completed a dual degree in medicine with a Masters of Arts in Biomedical Ethics at Midwestern University in Glendale, AZ. She went on to complete a general neurosurgery residency at Philadelphia College of Osteopathic Medicine in Philadelphia, PA.

Dr. Beasley has completed fellowships in Stereotactic Radiosurgery at Cooper University Hospital in Camden, NJ, and Functional and Restorative Neurosurgery at the Cleveland Clinic in Cleveland, OH. While at the Cleveland Clinic, Dr. Beasley participated in a special concentration in neuroethics. She has also completed a clinical scholarship in advanced epilepsy surgical techniques.

Dr. Beasley is one of the only dually credentialed neurosurgeon bioethicists in the world. She is fully trained as a general neurosurgeon in cranial and spinal trauma, endoscopic and open tumor surgery, radiosurgery, complex disorders of the spine including tumor and degenerative spinal disease and epilepsy surgery and neuromodulation.

Request a consultation with Dr. Beasley by calling 303-938-5700.

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