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Treatment team

All of us at The Stone Clinic share a core philosophy: a dedication to your well-being.

You’ll find that each of us brings a unique skill set to your treatment. We always take the time to listen, understand and explain carefully.



Ann W. Walgenbach, RN, FNP, MSN, RNFA, ONAnn W. Walgenbach, RN, FNP, MSN, RNFA, ON

Nurse Practitioner

Ann has worked with Dr. Stone since April 1992 as a nurse practitioner, surgical assistant, and clinical researcher. She attended the UCLA Graduate School of Nursing and has been a registered nurse for more than 30 years. Prior to joining The Stone Clinic, Ann worked at the UCLA Medical Center where she experienced a wide range of medicine including five years in critical care. Ann has two rough-and-tumble sons, Jake and Joe, a funny husband, and lots of animals.

Hope Horton, RNHope Horton, RN, BSN

Director of Patient Care

Hope has an extensive orthopedic background which began in 1993 when she worked at the Steadman-Hawkins Clinic in Vail, CO. She then went on to run the clinical aspect of a private sports medicine practice based in Greenwich, CT and Manhattan, NY. She lived and worked outside of Chicago for two years during which time she did clinical drug trials for an orthopedic and rheutmatology group. Hope is an avid road cyclist and also teaches spin classes. She is excited to be in an area which offers such amazing outdoor activities and enjoys helping others recover from injuries and ailments so they can return to the endeavors they enjoy.

Physical Therapy

Stephanie Adams Gleason, DPT, OCS

Physical Therapist

Stephanie completed her graduate degrees at UCSF for both a Masters and Doctorate of Physical Therapy. She did her undergraduate studies at UCLA achieving a Bachelor of Science degree in Physiological Sciences and a minor in Art History. While at UCLA, she completed their three-year Sports Medicine Program and sailed on the collegiate varsity team.

Stephanie continues to take continued education courses to stay on top of the manual therapy field with Maitland-specific training. She enjoys motivating and challenging her patients to improve physically, while supporting their personal growth as they return to an elevated quality of life.

Stephanie is an animal lover and enjoys staying active with rock climbing, sailing, soccer, snowboarding, hiking and running. She is proficient in Mandarin and Spanish. Stephanie is an active member of the Treasure Island Sailing Club and plays in a competitive adult soccer league.

Susanne DeCosterd, MPTSusanne DeCosterd, MPT

Physical Therapist

We recruited Susanne to The Stone Clinic because of her excellence in working with complex shoulder, knee, ankle and spine problems. She previously managed an outpatient orthopedic physical therapy clinic. Susanne has implemented and directed aqua therapy programs and ski conditioning classes, as well as core-strengthening classes emphasizing proper body mechanics, ergonomics and return-to-work programs. She has completed the Folsom Long-Term Advanced Manual Therapy Course and received her undergraduate degree in exercise physiology from Chico State and her master’s in physical therapy from Western University in Pomona, CA. Susanne enjoys all outdoor activities including skiing, snowboarding, mountain biking, triathlons, tennis and camping. She has been featured on Living Well television for her expertise on osteoarthritis and exercise programs for people living with knee pain.

Natalie Mar, PT, DPTNatalie Mar, PT, DPT

Physical Therapist

Natalie earned her Doctorate of Physical Therapy from the University of the Pacific, in Stockton, California, after her undergrad studies in Kinesiology at Sonoma State. Her background includes lymphedema therapy, craniosacral therapy, myofascial decompresion, and osteopathic manual therapies. Natalie excels at combining physical therapy with fitness training, and she is focused on helping her patients exceed their expectations.

On her days off, you might find Natalie relaxing at Ocean Beach, dropping in on a yoga class, snowboarding, running, or catching a Frisbee. Natalie is often out with her four-legged friends whom she volunteers with at Northern California Family Dog Rescue.

Jake Bagley, DPT

Physical Therapist

Degrees: B.S. in Exercise Science, University of Montana, Doctor of Physiotherapy, Bond University, Australia

Additional qualifications & courses: DMS Pilates level 1 certification

Jake enjoys: Surfing, Snowboarding, Backcountry Skiing

Diagnostic imaging

Mark Coleman, CRT, AARTMark Coleman, R.T. (R)

Radiology Technician

As head of our X-Ray and MRI Departments since 1994, Mark is responsible for all of the images taken at The Stone Clinic, and he consistently obtains high-quality images to aid in the proper diagnosis of our patients. Mark handles all of the shipping and receiving for the Clinic as well. Mark graduated in 1993 from City College of San Francisco with an AS degree in diagnostic medical imaging. In addition, Mark is a talented artist, and his work is proudly displayed at The Stone Clinic.

John V Crues, III, MDJohn V. Crues, III, MD


John V Crues, III, MD, is a world-renowned radiologist, and he plays a significant role as a musculoskeletal specialist for many of The Stone Clinic’s patients. Dr. Crues received his MD at Harvard University, completed his internship at the University of Southern California in Internal Medicine, and completed a residency at Cedars-Sinai Medical Center in Internal Medicine and Radiology. He has authored numerous publications while continuing to actively participate in radiological societies such as the Radiological Society of North America, American College of Radiology, California Radiological Society, the International Society for Magnetic Resonance Medicine and the International Skeletal Society. Dr. Crues currently has ongoing research projects in orthopedic and rheumatologic MRI. He has published over 100 articles, 20 textbook chapters, and eight textbooks in the medical literature.


Jaime RobinsonJamie Gibeaut, NRCMA, LXT, ABOC, NCLC

Senior Practice Administrator and Billing Manager

Jamie has an extensive background with medical insurance billing and coding within a surgical private practice, in addition to having clinical experience as a certified medical assistant. She serves as a liaison between our patients and their health insurance companies. She assists patients with obtaining reimbursement from their insurance companies and counsels patients on the financial aspects of their care at The Stone Clinic. She studied Business Management at Trident Technical College and received her Medical Assistant Degree from Centura College, both in Charleston, SC. Jamie spent eight years in Charleston working with ophthalmic surgeons and optometrists, but she is very excited about the transition to the field of sports medicine. As a newcomer to the Bay Area, Jamie loves exploring the city, traveling, surfing, and enjoying all of the outdoor activities that San Francisco has to offer.

Cristina Villanueva

Surgical Coordinator and Patient Concierge

Before joining The Stone Clinic, Cristina was the Office Manager for a busy Podiatric surgical practice in downtown Chicago for five years. As a native Californian, she endured all of the challenges of the brutal Chicago winters before returning to her home state. She has a degree in General Studies and brings her organizational talents, people skills, and positive attitude to The Stone Clinic team of respected professionals.  Cristina is eager to expand her medical administrative knowledge and experience to service the exciting field of Orthopedic sports medicine.  She enjoys traveling,  running and exploring new places in The Bay area.

Hali Klamm, EMT, CNA

Consultation Coordinator

Hali coordinates patient consultations and provides nursing support at The Stone Clinic. She attended Colorado State University where she obtained her Bachelor of Science in Food Science and Human Nutrition with a concentration in Exercise Physiology in addition to becoming a Nurse’s Assistant and Registered Emergency Medical Technician. She has previous nursing experience working on a Medical/Surgical Floor, Emergency Room, and Pediatric Emergency Room. Hali plans to pursue a career as a Physician Assistant.

Amanda Lam

Front Office Coordinator

Amanda is a San Francisco native who attended the University of California, Santa Cruz where she obtained her Bachelor of Science in Biology and a Minor in Education. Growing up, she has always enjoyed being active and playing sports.  It was during her younger years that Amanda gained a passion for volleyball and track and field.  She enjoys caring for others and is excited to be working at a medical office where she can gain more knowledge about Orthopedics.   In the future, Amanda plans to pursue a career in Nursing in order to continue her devotion to ensure patients receive high quality care. Amanda loves embarking on new experiences and traveling with friends.

Ella Corpuz, Associate Surgical Coordinator at The Stone Clinic in San FranciscoElla Corpuz

Associate Surgical Coordinator

Ella works with patients to facilitate their surgical scheduling. She graduated from UC Davis with a BS in Psychology. She volunteers with homeless communities in both education and health care.  As a California native and active sports enthusiast, Ella is enthusiastic about applying her knowledge to assist patients in every facet of their health care.  Ella plans to one day attend medical school; for now, she enjoys traveling, snowboarding, and exploring the fine eateries of San Francisco.


Jonathan Pelsis, MHSJonathan Pelsis, MHS

Director of Research & Operations

Jonathan graduated from Syracuse University in 2005 with a BS in Computer Science and from the Johns Hopkins Bloomberg School of Public Health in 2007 with a MHS in Biostatistics. He has been staff researcher at Stone Research Foundation since 2008 and rose to his role as the senior research coordinator for the Foundation in 2010. Jonathan oversees all research programs including meniscus allograft transplantation, articular cartilage paste grafting, cartilage restoration and outcome assessment tool creation and validation. Additionally, he coordinates the Foundation’s educational programs, annual meetings and communication efforts. Jonathan is originally from Baltimore and is an avid cyclist.

Thomas TurekThomas Turek

Senior Scientist

Thomas focuses his research on orthopedics, biomaterials and product development. Prior to his affiliation with The Stone Clinic, he served with Genetics Institute of Cambridge Massachusetts and Massachusetts Institute of Technology’s Department of Chemical Engineering. Research publications include bone graft substitutes and advanced research into growth factor delivery for orthopedic, oral and maxillofacial indications. Thomas is also contracted to Stone Research Foundation where he directs a cartilage shell graft + stem cells study which may offer the world’s first minimally-invasive total biologic joint replacement.

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Kevin R. Stone · Jonathan R. Pelsis · Scott T. Surrette · Ann W. Walgenbach · Thomas J. Turek 

Stone, K.R., A. Freyer, T. Turek, A.W. Walgenbach, S. Wadhwa, and J. Crues. 2007.

Stone, K.R., A.W. Walgenbach, T.J. Turek, A. Freyer, and M.D. Hill. 2006.