Meet the SOS Medical team

Jeffrey VonderHaar — President & Chief Executive Officer

Jeffrey VonderHaar is the President and CEO of Specialized Orthopedic Solutions, Inc. and creator of the eCommerce Division. Jeffrey founded Specialized Orthopedic Solutions, Inc. (SOS Medical) in 2003 on the principles of providing quality Durable Medical Equipment with exceptional Customer Service. Working from the ground up, Jeffrey has assembled an experienced sales force though out Central & Southern California, a patient care division with years of experience collectively and an administrative team with exemplary skills. Today, SOS MEDICAL is an industry leading DME Company and has established a reputation of professionalism and integrity with the Surgeons they assist and the Patient’s they care for.

In his years prior to Specialized Orthopedic Solutions, Inc., Jeffrey worked as a Sales Manager for various Medical Device and Supply Companies including TEAM POST-OP where he grew his territory at staggering 177% in the first year and exceeded 1.9 million in annual sales in the years following.

Jeffrey is also Co-Founder of Sending out an ( — a non-profit organization assisting low income amputees around the world. His Organization was founded with a genuine desire to assist and provide those less fortunate with a better quality of life. Mr. VonderHaar is also on the Board of Directors of Ayuda ( a non-profit organization assisting Orphaned Children throughout Latin America with basic needs and provisions. Additionally, Jeffrey is proud supporter of Centro De Miembros Artificiales, a non-profit, prosthesis center, based in La Paz, Bolivia.

Jeffrey is married to Elizabeth Bress, has a wonderful little boy, and resides in Calabasas, California.

Jeffrey's Accreditations:
AAOP Accredited

Elizabeth Bress — Vice President

Elizabeth Bress is a Managing Partner of Specialized Orthopedic Solutions, Inc. Elizabeth is a graduate of UPSA in Santa Cruz, Bolivia obtaining degrees in Business Administration and English with a Masters in Marketing.

As a Managing Partner, Elizabeth is responsible for overseeing new business/product development. Since her arrival in 2008, growth has increased by an average of 42% annually. Elizabeth began her career with Specialized Orthopedic Solutions, Inc. as a Territory Manager and quickly proved to be a Top Producer and Leader while exceeding sales expectations year after year.

In her years prior to SOS Medical and following graduation; Elizabeth moved to New York City to work as a Production Manager with Pachamama Films. Soon thereafter, she found herself pursuing a career of acting and modeling in addition to her being crown Mrs. Bolivia International 2004. Eventually her acting career brought her to Los Angeles where she would experience yet another career change that would take on a more meaningful new direction.

In 2006, Elizabeth began a career in the medical field with Team Surgical working as a Sales Representative in Surgical/Capital Equipment Division. She quickly ‘cut her teeth’ in the Medical Field and developed strong and lasting relationships with the Orthopedic Surgeons in her respected Territory. That experience, coupled with her personal experiences, vast education, tenacious work ethic and the strong desire to succeed, only made her the ideal Managing Partner for Jeffrey VonderHaar and Specialized Orthopedic Solutions, later in her career.

Elizabeth is a Co-Founder of the non-profit organization Sending out an (; she is also on the Board of Directors of the non-profit organization Ayuda ( helping orphan children in Latin America and a key supporter of Centro De Miembros Artificiales-Bolivia ( helping amputees to get back on their feet.

It is relative to point out that Elizabeth was born with a ‘Congenital Physical Abnormality’ of her lower right leg; subsequently, she had 7 additional unsuccessful surgeries to correct the aliment that resulted in an amputation just below her right knee at age 11. Though what may seem as a deterrent for success or an obstacle in the pursuit of dreams has only fueled Elizabeth’s desire and need to assist others with similar predicaments.

Elizabeth has been the motivating factor and key initiative for the development of Specialized Orthopedic Solution’s — Prosthetic Division.

Dimitri Yagdjis — CPO

Dimitri Yagdjis began in the industry at the age of seven in his father’s custom shoe fabrication facility, Valley Oaks Orthopedic, Inc. As his position involved exposure with more orthotic and prosthetic devices and components, Dimitri began to seek out the education required. In 1991, he graduated from C.S.U., Dominguez Hills with a B.S. in Health Science, Orthotics and Prosthetics.

Dimitri spent the following ten years gaining experience through employment at various public and private institutions before rejoining his family business full time in 2001, and starting up a new division, American Medical Prosthetics and Orthotics, Inc. In 2012, after the passing of his father, the family businesses were sold.

Dimitri joined SOS in 2012 as their head CPO, enabling him to continue providing effective modes of treatment for all disorders requiring prosthetic and/or orthotic intervention. Dimitri is especially fond of the implementation of rehabilitative technology towards enhancing the quality of life for his past and present patients.

Stefan Knauss — Specialist in Aesthetic Restoration

Stefan Knauss has been fascinated by prosthetics since he created a wooden mechanical hand for a high school competition. Stefan has a Masters of Associated Medical Sciences from the University of Illinois at Chicago’s Craniofacial Center in the Department of Maxillofacial Prosthetics. He also studied prosthetics and orthotics (bracing) at Northwestern University's School of Prosthetics and Orthotics in Chicago, and art at Occidental College and the Art Center College of Design. He is a member of the American Anaplastology Association and is certified in Prosthetics and Orthotics by the American Board of Certification for Prosthetics and Orthotics. Trained as an Orthotist and Prosthetist but also as an Artist, Stefan started his career in 1988 as an apprentice to other professionals.

With 25 years of experience; Stefan Joins the Specialized Orthopedic Solutions team to bring the functionalist issues to bear on his artwork and vice versa. By bringing together techniques from several traditionally-distinct disciplines; Stefan has been able to bridge the functionality aspect of prosthetic limbs and the aesthetics allowing our clients to guide him in where the tradeoffs need to be, if there are any.