Our Team

Advanced-Practice Providers

All of our doctors work with physician assistants (referred to as PAs) and nurse practitioners (referred to as NPs) in order to provide the best possible care for their patients. PAs and NPs are an integral part of our orthopaedic team, as they help to treat and diagnose patients in our office and in the hospital. This team assists our orthopaedic doctors in performing surgeries and with these responsibilities:

  • Recording patients' medical history
  • Performing physical exams
  • Performing and ordering tests
  • Educating patients on musculoskeletal health
  • Administering injections to minimize joint pain
  • Prescribing medications

Training: To become a PA or an NP, one needs to complete six years of combined undergraduate and graduate education. Some complete an additional year of training to specialize in a specific area of medicine. After their training, PAs and NPs must pass a board certification exam prior to entering a practice. They also carry their own malpractice insurance as well as their own license to prescribe medications.

Our PAs and NPs have trained on the intricacies of musculoskeletal health for many years. They are highly skilled professionals who exercise autonomy in diagnosing and treating illnesses the same as their physician counterparts. They evaluate and treat more orthopaedic patients in a year than all of the local urgent cares and emergency rooms combined. Hence, they are more experienced in the management of orthopaedic conditions than many non-orthopedic medical doctors.

Our Physician Assistants

Vaz Galstjan, P.A.-C

Galstian YazVaz Galstjan is a Board Certified Physician Assistant (PA-C) in the state of California. He has many years of experience as an Orthopaedic PA starting his career in 2004, as well as many years of experience in the operating room prior to becoming a PA-C.

He graduated from Charles Drew University of Medicine and immediately went into the field of orthopaedics where he trained and worked with many orthopaedists in the San Fernando Valley. Mr. Galstjan is a member of California Academy of Physician Assistants and American Academy of Physician Assistants.


Omar Duenes, P.A.-C

Duenes OmarOmar Duenes is a Board Certified Physician Assistant (PA-C) in the state of California. He completed his undergraduate degree at California State Polytechnic University, Pomona. He then went onto Western University to complete a two-year Masters Degree at Western University, followed by a one-year postgraduate residency program in Orthopaedics at Arrowhead Regional Medical Center.

Mr. Duenes received his license as an Orthopaedic PA In 2005. After his training, Mr. Duenes immediately went into the field of orthopedics where he worked with many orthopedic doctors in the Inland Empire. Mr. Duenes is a member of California Academy of Physician Assistants and American Academy of Physician Assistants.


Cynthia Pezeshgian, RN

Throughout her education, Ms. Pezeshgian was on her school’s academic dean’s list, and she was awarded numerous scholarships (Honor Student Scholarship Recipient, Alumni Scholarship Recipient).  Having prior work experience in musculoskeletal care at another health facility, Ms. Pezeshgian understands the patients’ educational needs in orthopaedics and pain management.  She is your advocate – guiding you, the patient, to the right resources as you seek and get care at OSS.  She wants each patient to be better informed so each can make the best decision.

She enjoys volunteering at community health events.

Favorite hobby:  Going on hikes to put her mind at ease and enjoy the beauty of nature.