Our Teams

Dr. Daniel Laster

Dr. Daniel Laster

Fellow of the American Academy of Orthopaedic Surgeons


Dr. Laster attended college at Pomona College in Claremont, California where he starred as an all-conference linebacker for four years. He received his Bachelor of Arts in Biology. After his undergraduate studies, he traveled to Washington, D.C. to enroll in medical school at Georgetown University. While at Georgetown, Dr. Laster was admitted into the Alpha Omega Alpha Honor Medical Society. He received his Medical Doctorate in 1995 and started his training in orthopaedic surgery at Tulane University in New Orleans, Louisiana. While at Tulane, Dr. Laster received intensive training in all disciplines of orthopaedic surgery. He is extremely well versed in the specialty of trauma, having served several years of his residency at Charity Hospital New Orleans, a level one trauma center. He graduated from Tulane in 2000.

Dr. Laster joined Risser in the year 2000 and has practiced as a board certified orthopaedic surgeon since that time. His interests include trauma and the disorders of the hip and knee. He specializes in total joint replacement including computer navigated surgery as well as total hip arthroplasty through the anterior approach. He has staff privileges at the Huntington Outpatient Surgery Center, Huntington Memorial Hospital and Arcadia Methodist Hospital. He is a member of the California Orthopaedic Association, the Western Orthopaedic Association, Los Angeles County Medical Association and is a Fellow of the American Academy of Orthopaedic Surgeons. Dr. Laster grew up in Palo Alto, California as the youngest of eight children. He has been involved in the Pasadena region of AYSO and is currently in his fourth year as a head coach. Dr. Laster and his wife, live with their two children in Pasadena and enjoy being involved in the Pasadena and Altadena communities.

Dr. Donald Norquist

Dr. Donald Norquist

General Orthopaedic Surgeon


Following in the footsteps of his physician father, Dr. Donald M. Norquist, Dr. Donald J. Norquist completed his undergraduate and medical school training at the University of Southern California. While at the Orthopaedic Hospital in Los Angeles Dr. Norquist began to specialize in orthopaedics. He has also served as the president of the executive committee and member of the board of trustees at St. Luke Hospital. Dr. Norquist was a clinical instructor in Orthopaedics at USC School of Medicine and was the president of the medical alumni association in 1980. For the last 38 years, he has been a dedicated member of the medical community in Pasadena

Dr. Gregory Northrop

Dr. Gregory Northrop

Board Certified Orthopaedic Surgeon

Sports Medicine Subspecialty Board Certified


  • Knee and Shoulder Surgery
  • Arthroscopy and Sports Injuries
  • Knee Replacement (Partial and Total)
  • Shoulder Replacement (Standard and Reverse)

Dr. Northrop is a board certified, sports medicine fellowship-trained orthopaedic surgeon. He graduated from UC Berkeley with a degree in economics. After working in healthcare consulting for 5 years, Dr. Northrop returned to medical school, obtaining his medical degree from Columbia University College of Physicians and Surgeons in New York. He completed a surgical internship at UC San Francisco and subsequently completed his orthopaedic residency at Stanford University. After finishing his residency, Dr. Northrop obtained additional training in sports medicine and arthroscopy at the West Coast Sports Medicine Foundation.

Dr. Northrop’s specialty areas include operative and non-operative management of sports injuries, arthritis and fractures. He performs all types of knee and shoulder surgery from arthroscopy, ACL reconstruction and rotator cuff repair to partial and total joint replacement. He can therefore appropriately address whatever issue you may have with your knee or shoulder. His philosophy is that people of all ages should remain as active as possible, and as such, his goal is to restore injured or hurting patients to their previous level of function. Whenever possible, conservative non-operative approaches are tried first. When surgery is required, Dr. Northrop employs a variety of approaches, including minimally invasive arthroscopic techniques.

Dr. Northrop was raised in Los Angeles and currently lives in Pasadena. In his spare time he enjoys golfing, skiing, mountain biking and spending time with his family.

Dr. Ben Pradhan

Dr. Ben Pradhan

Board Certified And Fellowship Diplomate Spine Surgeon


  • Surgery of the Cervical, Thoracic,and Lumbar Spine
  • Specializing in Minimally Invasive Surgery and Microsurgery of the Spine

Click here for Dr. Pradhan's Curriculum Vitae

Dr. Ben B. Pradhan is a board certified and fellowship trained Orthopaedic Spine Surgeon, whose practice focuses solely on spine problems. He treats cervical, thoracic, and lumbar spinal disorders. As the former Director of Clinical Research, and Spine Surgery Fellowship Coordinator at The Spine Institute of Santa Monica, CA and Cedars-Sinai Medical Center, he has been very involved in research and teaching within the ever changing field of spine surgery. He presently heads the spine surgery department of the Risser in Pasadena, CA. Risser is one of the most established orthopaedic groups in Southern California, established in 1937, and one with a long tradition of spinal care.

Dr. Pradhan is a Princeton graduate. He started his education and career as an aerospace engineer, but was drawn toward the engineering and technological advances being made in the field of spine surgery. After completing high school as valedictorian, he graduated from Princeton with academic honors, was recruited by UCLA for a PhD in aerospace engineering with a UC Chancellor's fellowship where he was nominated for outstanding graduate engineering student, and completed his MD training at UCLA with a Dean's scholar recognition. He completed his orthopaedic surgery residency at UCLA and his spine surgery fellowship with Dr. Rick Delamarter, whom he subsequently joined as a partner at The Spine Institute (Santa Monica, CA - now at Cedars-Sinai) for the next four years. Dr. Pradhan joined Risser on a part time basis for two years following the untimely passing of his predecessor Dr. Charles Prickett there. Dr. Pradhan fully moved his practice to Risser in Pasadena in August 2008.

During the course of his extensive education and training, and subsequently his practice and teaching, Dr. Pradhan has compiled over 300 peer reviewed scientific publications, presentations, abstracts, and posters. He has presented his experience on topics of modern spine surgery in major spine surgery research and medical society meetings internationally as well as nationally. He has also been awarded various honors from major spine surgery societies.

Dr. Amir Mostofi

Dr. Amir Mostofi

Board Certified Orthopaedic Hand Surgeon


Dr. Amir Mostofi attended high school in Bakersfield, California and spent time volunteering in several hospitals. This was when he knew he wanted to pursue a career in medicine. As a pre-medical student at UCLA he graduated Magna Cum Laude and with departmental honors in physiological sciences. Dr. Mostofi then moved to Chicago to attend the Rosalind Franklin University of Medicine and Science. He graduated at the top of his medical school class graduating with Alpha Omega Alpha Honors. He spent the next several years in Connecticut for his orthopaedic surgery training at the University of Connecticut. Over the years, Dr. Mostofi has contributed to several books and peer-review publications. He spent his last year of training at Brown University, specializing in hand, upper extremity, and micro-vascular surgery. Training under the direction of Dr. Edward Akelman and Arnold Peter Weiss, two world renowned leaders in hand surgery, Dr. Mostofi has gained tremendous expertise in complex hand disorders. He has finally returned home to Southern California, and we are very proud to have him with us at Risser.

Dr. Mostofi devotes his practice to complex hand, wrist and elbow injuries. He has expertise in caring for common hand problems such as carpal tunnel syndrome as well as fractures, sports injuries, arthritis, and nerve problems in the hand, wrist and elbow. He holds staff privileges at the Huntington Outpatient Surgery Center, Huntington Memorial Hospital and Arcadia Methodist Hospital.

Dr. Mostofi also dedicates significant time to research and teaching. He spends every Wednesday at Keck Medical Center as an assistant clinical professor at USC department of Orthopaedic surgery. He has a true passion for continued learning and education. He plays an active role in the residency and USC - Joseph H. Boyes Hand Fellowship.

Dr. Mostofi lives in La Canada with his wife and two sons. His favorite weekend activity is going for walks with his family, barbequing and watching football.

Dr. Braden Criswell

Dr. Braden Criswell


Dr. Criswell specializes in treating foot and ankle injuries as well as offering general orthopedic care. Before joining the medical team at Risser he was the Clinical Instructor in Foot and Ankle Surgery at Stanford University Medical Center. Dr. Criswell graduated from UCLA before attending the USC Keck School of Medicine and completed his residency at Vanderbilt University and his fellowship and clinical instructorship at Stanford.

At Risser, Dr. Criswell will use his expertise to treat a range of foot and ankle injuries, specializing in patients with sports injuries. He will also work with primary care providers, rheumatologists, pain specialists neurologists, physical and occupational therapists as well as surgeons and other specialists to optimize patient care before and after foot surgeries. He loves spending time with his growing family where they now live in Pasadena.

Dr. Jared Myers

Dr. Jared Myers

Physical Medicine and Rehabilitation (PM&R) specialist / Physiatrist


  • Physical Medicine and Rehabilitation, Board Certified.
  • Pain Medicine / Interventional Pain Management


  • Electrodiagnostic Medicine (EMG/NCS)
  • Regenerative Medicine (Prolotherapy, Platelet Rich Plasma, and Stem Cell Therapy)
  • Osteopathic Manipulative Medicine
  • Medical Acupuncture

Dr. Myers is a board certified Physical Medicine and Rehabilitation (PM&R) specialist (physiatrist), who is fellowship trained in pain medicine including interventional pain management. He attended California State University of Northridge and double majored in biology and chemistry. Dr Myers gravitated towards medical institutions that embody his long held deep belief in whole person care. He obtained his medical degree from Western University of Health Sciences College of Osteopathic Medicine of the Pacific (COMP), where compassion and a holistic hands-on approach is valued above all else. He was honored to have been elected chief resident (2014-2015) at Loma Linda University Medical Center, where he completed his residency and fellowship training, and where the core integrative principle is encapsulated by organization’s motto, To Make Man Whole. During his pain medicine fellowship Dr Myers obtained additional training and certification in medical acupuncture (at Helms Medical Institute) to widen his already extensive non-operative pain alleviating skill set.

Dr. Myers’ core passion and true satisfaction comes from treating pain and loss of function, the two symptoms he feels are the most devastating to a person’s daily life. As such he employs all non-surgical modalities to treat the full scope of spinal, musculoskeletal, peripheral joint and nerve disorders. He treats high functioning sports athletes to geriatric patients with degenerative arthritic conditions. He performs electrodiagnostic (EMG) evaluations, advanced minimally invasive fluoroscopy and ultrasound guided injections, spinal cord stimulation (neuromodulation) implants, osteopathic manipulative medicine and acupuncture.

Dr. Myers is proud to have joined the Risser family in 2016 and is available at both the Pasadena and Arcadia offices. He additionally holds privileges at Huntington Memorial Hospital and ambulatory surgical center.

Born and raised in Johannesburg, South Africa, Dr Myers and his two younger brothers grew up in a health conscious vegetarian household in which physical fitness was heavily emphasized. He recently moved to Glendale with his wife and daughters and is excited to become an active part of the community.



Board Certified Orthopaedic Surgeon

Sports Medicine Subspecialty Board Certified


  • Shoulder Arthroscopy and Joint Replacement Surgery
  • Knee Arthroscopy and Joint Replacement Surgery
  • Sports Medicine

Fellowship-trained and specializing in Shoulder and Knee Complex Arthroscopy and Joint Replacement Surgery for over two decades, Dr. Gregory T. Heinen, M.D., leads his staff in their commitment of providing high-quality orthopaedic care in his childhood home, the San Gabriel Valley.

Anchoring the Arcadia office, Dr. Heinen and his specialized team are known for their personalized service and ability to address your orthopaedic needs with advanced conservative and surgical techniques. Emphasizing cutting-edge sports medicine care, he performs complex shoulder and knee reconstruction alternatives to optimize function and pain control. As the founder of the California Sports and Cartilage Institute, Dr. Heinen also utilizes advanced techniques including PRP, stem cell lines and cartilage implantation techniques to aid healing and prevent premature arthritic change.

A graduate of Yale Medical School, Dr. Heinen obtained his Orthopaedic training at USC and his Fellowship Specialty Training in Shoulder and Knee Arthroscopy and Sports Medicine at SCOI. Dr. Heinen is Board-Certified in both Orthopaedic Surgery and Orthopaedic Sports Medicine. He has been the team doctor for University of California, Riverside; California State University, San Bernardino; California Baptist University, and Loyola High School. Committed to ongoing education, Dr. Heinen taught nationally as an Associate Master Instructor in Shoulder Arthroscopy and was the Medical Director for the California Baptist University Athletic Training Education Program. He frequently educates upcoming health-care providers locally.
True to his community roots, Dr. Heinen resides with his wife, dogs and visiting adult children locally, calling the San Gabriel Valley his home.

Dr. Swapnil Shah

Dr. Swapnil Shah

Orthopedic Surgeon; Traumatology

Dr. Swapnil Shah is an Orthopaedic Surgeon with extensive training in orthopaedic trauma, acute injury and complications. His areas of expertise include surgery of complex fractures of the extremities and the pelvis, nonunion, malunion/deformity and infection of the bone. His skill set extends beyond trauma, as Dr. Shah is highly proficient in hip replacement through the anterior approach which spares tissues and speeds recovery.

Dr. Shah understands that having an injury is unexpected and overwhelming. His goal is to work together to determine the best treatment plan, be it conservative or surgical. His ultimate mission is to make you feel comfortable and confident as you progress to your optimal outcome.

Dr. Shah went to the University of Southern California Keck School of Medicine, Medical School. He then pursed his Orthopaedic Residency at the esteemed San Francisco Orthopaedic Residency Program. Deciding that fracture care and reconstruction were his true calling, he attended the University of Maryland Shock Trauma Fellowship to gain a special learning experience from one of the world’s best training facilities.

Since 2010, Dr. Shah dedicated himself to the East Bay Community as one of the premier Orthopaedic Trauma Specialists in the area. He has been providing orthopaedic care to all patients regardless of their background or ability to pay. Recently, he has decided to make his way back home to the San Gabriel Valley and join the Risser family to continue to serve the community and dedicate himself to excellent patient care.

Virginia Mabasa, PA-C

Virginia Mabasa, PA-C

PM&R specialist

Virginia Mabasa began her career in medicine when she joined the US Navy in 1989. She was accepted to Hospital Corpsman school shortly after completing boot camp, then applied to Surgical Technologist school where she graduated in 1991.

While working as a scrub tech in the operating room in Okinawa, Japan, she developed an interest in orthopaedics after assisting in several trauma cases. Her motivation and dedication to learning all aspects of the service led her to be selected as the Senior Surgical Tech and First Assistant in Orthopaedic surgery despite her junior rank. For her work she was bestowed with the Navy Achievement Medal upon being honorably discharged from the Navy in 1994.

She decided to return to school and pursue a degree as a Physician Assistant (PA) due to the connection between Corpsman and PA's. In 2001 she graduated with honors from the University of Southern California (USC) with a Bachelors in Physician Assistant Studies.

While working in pain management, she developed a strong interest in geriatrics due to her experience working with a large senior population. She decided to return to USC to pursue a Masters degree in Gerontology and graduated with honors in 2013.

Mrs. Mabasa is a board-certified bilingual (Spanish-English) PA with over 15 years experience in Pain Management. She believes in empowering her patients by arming them with knowledge about their conditions, while following a multidisciplinary approach when formulating a treatment plan.

Mrs. Mabasa specializes in general pain management and is adept in managing various orthopaedic and neuromuscular conditions. She splits her time seeing patients at both the Pasadena and Arcadia offices.

Outside of work she can be found spending time with her family and pets. Her hobbies include lifting weights, Crossfitting, and roller derby.


Laura Martinez

Practice Manager


Sofia Venegas

Administrative Assistant

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Clinical Administrative Assistant to Dr. Laster

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Clinical Administrative Assistant to Dr. Northrop

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Clinical Administrative Assistant to Dr. Mostofi

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Clinical Administrative Assistant to Dr. Criswell

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Angelina Cruz

Clinical Administrative Assistant to Virginia Mabasa PA-C

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Serina Ramirez

Clinical Administrative Assistant to Dr. Shah

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Zayra Montenegro

Clinical Administrative Assistant to Dr. Myers

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Joel Acosta

Clinical Administrative Assistant to Dr. Heinen

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Mariella Martinez

Surgery Scheduler to Dr. Pradhan

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Joshua Pang

MRI Technician in Pasadena

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Jose Ibarra

X-Ray Technician

Logan Wheeler

X-Ray Technician

Jorge Partido

X-Ray Technician


Marie Brock

QME Coordinator

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Liliana Marin

Work Comp Coordinator



Andrea LeDeay

Revenue Cycle Manager



Billing Specialist

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Evelyn Esparza

RSC Surgery Biller

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Frank Apraku

Authorization Coordinator

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Kelly Winters

Surgery Coder

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Lorena Saavedra

Billing Specialist

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Tiffany Tate

Medical Records

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Celeste Escobedo

Injection Scheduler

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Lisa Montoya

Surgery Scheduler

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