Laura Acuna
Front Office Coordinator

Laura first joined the Joint Replacement Institute in 2002 as a Patient Relations Coordinator.  During the transition to St. Vincent Medical Center, Laura assumed the duties of Front Office Coordinator.  She is responsible for overseeing the daily operations of the front office at JRI.  Laura ensures that the front office personnel strive to meet the patients’ needs and provide excellent service.  In addition to this, Laura coordinates surgery scheduling for Dr. Amstutz.


Laura was born and raised in Los Angeles and graduated from UCLA in 1994 with a B.S. degree in Psychobiology.  During her spare time, she enjoys spending time with her husband and family.

Carol Aldana
Administrative Assistant

Carol has worked in healthcare since 1997.  She first joined the Joint Replacement Institute in 1996 as a Patient Relations Coordinator.  During transition to St. Vincent Medical Center, Carol assumed the duties of Administrative Assistant to both Drs. Schmalzried and Mynatt.
Carol is responsible for the daily administrative operations for both doctors. In addition, to this, Carol coordinates surgery scheduling for Dr. Schmalzried.

Carol was born and raised in Los Angeles, obtained her A.A. degree in Liberal Arts and currently in the process in obtaining her B.A. in Health Care Administration.   Carol has two girls whom she loves deeply.  When not at JRI, she can either be found on the soccer field watching her daughter play or signing karaoke with her husband, Jimmy.

Neal Cook
Radiology Technician

Radiology Technician Neal Cook is the “bone photographer” at the JRI and has worked with the doctors for many years, perfecting the X-ray views that help them evaluate their patients.

After his graduation from the U.S. Air Force Radiology Program with honors, he worked at Orthopaedic Hospital as part of the team that helped doctors diagnose and treat the many children and adults with bone disorders.


An avid bicycle rider, he enjoys cooking, camping and hiking in the mountains, and spending time with family and friends.

Michel Le Duff

Michel is a native of France where he completed his undergraduate studies in kinesiology in 1983. After moving to the United States Michel continued his study of human movement at California State University in Northridge. In 1997, he completed with distinction his Masters degree in Kinesiology, with a specialization in Biomechanics.


As Research Lead, Michel is responsible for database development, statistical analysis, preparation of presentations and writing of the materials, methods and results sections of manuscripts related to Dr. Amstutz’s practice.


When not preparing reports regarding ongoing research at the Joint Replacement Institute, Michel enjoys spending time with his wife, Kim, and daughter, Cécile. He also enjoys skiing and rock climbing in the local southern California mountains or the Sierra Nevada.


View the Curricula Vitae of Michel Le Duff
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Candy Escalante
Certified Medical Assistant

Candy has 15 years of experience in the medical field and spent seven of those working as a Medical Assistant in orthopedics prior to joining the JRI.  After obtaining her certification as a Medical Assistant, she went back to school and graduated as a Surgical Technologist, trained for year and decided that assisting the physician in the clinic is what she enjoys best.

Candy always has a smile, enjoys working with the JRI team and is always available to lend a helping hand to patients and co-workers.
In her spare time she likes doing family activities with husband Eduardo and their children, Peter and Tori. She also is an active member of her parish.

LaVonda Hodge
Medical Assistant

LaVonda has worked as a Medical Assistant since 1998.  She Joined the Joint Replacement Institute in 2004 after working in podiatry for three years.  She works primarily with Dr. Schmalzried and is responsible for assisting him in the clinic and submitting authorization requests for surgery. LaVonda assists the Surgery Scheduler with paperwork for surgical patients.

She also assists Dr. Amstutz and all JRI surgeons in the clinic.

LaVonda enjoys working with the JRI because she feels she is part of a large family.  When not working, she enjoys spending time with her daughter, family and friends.

Evelyn J. Morales
Medical Receptionist

Evelyn Morales has more than 10 years of experience as a Medical Receptionist.  She joined the Joint Replacement Institute team at the time of its transition to St. Vincent Medical Center.

You may see Evelyn at the front window when you arrive for your appointment with one of the JRI physicians.  Evelyn answers the main line, schedules patient appointments and takes the necessary information required to ensure documents are organized and prepared in a timely fashion for each patient.

Evelyn loves to spend time with her family going to the park and the beach. She especially enjoys drawing and coloring with her three kids.

Patti O’Brien
Administrator of Orthopedic Services

Patti O’Brien is the Administrator of Orthopedic Services at St. Vincent Medical Center and oversees the administrative operations of the Joint Replacement Institute.  She is a licensed Physical Therapist and has practiced in the physical therapy field since 1983.

Patti earned her B.S. in Health Science/Physical Therapy at California State University Northridge in 1996.  Her clinical background includes Orthopedics, Joint Replacement, Trauma, Neurological Impairments, Wound Care, Cardio-thoracic surgical patients, Pulmonary Rehab, Work Hardening and Chronic Pain Management.

Patti managed the Arthritis and Spine Institutes at Hollywood Presbyterian Medical Center for two years prior to joining the Joint Replacement Institute at St. Vincent Medical Center in March, 2007.  She enjoys camping with her husband, family and friends, hiking, and dirt bike riding.

Jovita Bautista-Ortega
Administrative Assistant

Jovita Ortega is a native of the Philippines. She graduated from California State University, Los Angeles in 1990 with a B.S. degree in Health Science and from National University, Los Angeles in 1998 with an M.B.A. in Health Care Administration.

As an Administrative Assistant, Jovita is responsible for the daily administrative operations to Dr. Amstutz’s practice, organizing his outside clinics, coordinating the fellowship program (both clinical and research), and monitoring the JRI website e-mails.

In her spare time, Jovita transports her three children Andrew, Brandon, and Sidney around town to baseball and softball practices and/or games, hula, and piano. In her spare time, she enjoys taking salsa classes and salsa dancing.

Martha Tijerino-Ortega

Martha is a native of Nicaragua where she lived until the age of eight. One of the earlier JRI staff members, she joined JRI in 1991 and worked originally as a patient coordinator for Dr. Amstutz before dedicating some time to her own business.  She is now back as a research assistant in charge of data entry, correspondence with study sponsors, and handling of the numerous outside clinics for Dr. Amstutz’s patients.  Martha is also currently pursuing her education to become a Registered Nurse.

Mother of 2 children, she spends most of her free time with her kids Mark and Brittney. You can find Martha on Saturday afternoon cheering her son on the football field.

Lisa Price
Health Information Management Technician

Lisa Price is the Health Information Management (Medical Records) Tech. She is in charge of maintaining all medical records for the JRI and has been in the medical records industry for more than 15 years.

Lisa’s hobbies are family outings, such as watching her son play football at Purdue University and her nephew play semi-pro football with the Long Beach Lions. She also likes listening to jazz, watching old karate movies and watching NASCAR Racing.

Blanca Rivas
Surgery Coordinator

Blanca Rivas joined the Joint Replacement Institute as a Surgical Coordinator in April 2007.  Prior to joining the JRI, Blanca was the Surgical Coordinator at the Arthritis and Spine Institutes at Hollywood Presbyterian Medical Center.  She has been in the medical field for nearly 10 years.
Blanca is a Certified Programmer Analyst and Technical Computer Operator.  She obtained her certification in El Salvador, Central America.  She has completed one year toward a Psychology major at Fullerton College and one year of Medical Assistant education.
Blanca is responsible for coordinating the surgical process for Dr. Mynatt’s patients, as well as tracking the JRI surgeries for our surgeons and the Administrator.

One of her hobbies is enjoying outdoor activities with her husband and their three children.

Mylene dela Rosa

Mylene is a native of the Philippines.  She graduated from the University of Southern California in 1993 with a B.S. degree in Biomedical and Mechanical Engineering.  She is a Certified Clinical Research Professional and a member of the Society of Clinical Research Associates.


As Clinical Research Coordinator, Mylene is responsible for various aspects of Dr. Schmalzried’s clinical study trials.  She maintains relations with study sponsors and with the Institutional Review Board.  She is responsible for data collection and database management related to Dr. Schmalzried’s patients. Mylene originally joined the staff of the Joint Replacement Institute in 1993 as a Research Technician in the Implant Retrieval Lab.

Mylene enjoys her spare time with her husband, Cruz Rivas, and their daughters, Olivia and Beatriz.  She volunteers with her daughters’ soccer and softball teams.  She has a second-degree black belt in Gosoku Ryu karate.

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Millisa C. Thomas
Medical Assistant Supervisor/Clinical Research Coordinator

Millisa Thomas is the Medical Assistant Supervisor for the Joint Replacement Institute and the Clinical Research Coordinator for Dr. H. Michael Mynatt.  Millisa obtained her Medical Assistant diploma at Watterson College in West Covina, CA where she graduated with a 4.0 GPA and as class salutatorian.

Millisa has been a Medical Assistant for 20 years and has been a Clinical Research Coordinator for the past year. Millisa was instrumental in obtaining the IRB approval for the Ceramic on Metal IDE study that is being conducted currently at SVMC and nine other sites in the U.S. 
Millisa is currently enrolled at Colorado Technical University where she is studying to obtain her B.S. in Healthcare Management.  She enjoys traveling and spending time with her children and friends.

Lauren Wisk
Clinical Research Coordinator

Lauren Wisk is a recent graduate of the University of California, Los Angeles (UCLA) with a B.S. in Molecular, Cell and Developmental Biology. While at UCLA, Lauren was a Research Assistant for the UCLA Stroke Team and earned an internship with the American Heart Association (AHA), conducting research on a novel MRI sequence used for diagnostic imaging of the carotid arteries.


As a new member of the staff at JRI, Lauren works a Clinical Research Coordinator for Dr. Amstutz. She is responsible for managing data for various clinical trials and contributing to manuscripts on the subject of Dr. Amstutz’s research.


In her spare time, Lauren enjoys swimming, surfing and snowboarding.