Vladimir Radivojevic, MS, MBA, FACHE, Chief Executive Officer

Vlad brings more than 24 years of healthcare leadership experience to his role as Chief Executive Officer of Rehabilitation Hospital of Northern Indiana. His background spans acute care, surgical, oncology, and rehabilitation services, with a strong track record in hospital operations, physician engagement, and strategic growth.

Before joining the hospital, Vlad served as CEO of a Level I trauma center and teaching hospital, where he led major operational and financial improvements. He also has held multiple executive leadership roles, overseeing hospital operations, strategic service line growth, and quality improvement initiatives.

A licensed physical therapist, Vlad began his career in clinical rehabilitation and has led therapy programs across hospital, outpatient, and long-term care settings.

Vlad is a Fellow of the American College of Healthcare Executives and is board-certified in Executive Healthcare Leadership. He earned a master’s degree in business administration from the University of Phoenix in Ontario, Calif. He earned a master’s degree in physical therapy and a bachelor’s degree in anatomy and physiology from Andrews University in Berrien Springs, Michigan.

A longtime Indiana resident, Vlad is passionate about delivering patient-centered care, serving others, and building strong, collaborative teams. Outside of work, he can be found traveling with his wife and family, enjoying outdoor adventures, rock climbing, and expanding his culinary skills in the kitchen. Vlad is active in his local church and mentorship programs.

Nathaniel V. Zuziak, D.O., Medical Director

Nathaniel is a physiatrist board certified by the American Board of Physical Medicine and Rehabilitation (ABPMR) and American Board of Quality Assurance and Utilization Review Physicians (ABQAURP). He is the Founder and Chief Medical Officer of Transcendent Physiatry & Rehabilitation LLC and previously served as the Medical Director of Indianapolis Rehabilitation Hospital as well as Lafayette Regional Rehabilitation Hospital. As medical director, he was the physician leader accountable for the management of the treatment team and medical staff, quality of care, safety initiatives, and the physician processes.

Dr. Zuziak treats a wide variety of neuromusculoskeletal conditions but holds particular interests in spinal cord injury, spasticity, preventative medicine, healthcare technology and future models of health care delivery. He has authored and co-authored multiple research projects and manual chapters involving spinal cord injury, travel, and accessibility which have been presented at national conferences. As a resident physician, Dr. Zuziak served as the President, Past President, Board of Governors ex-officio member, and Medical Education Committee Liaison for the American Academy of Physical Medicine and Rehabilitation’s Physiatrist in Training Council.

Dr. Zuziak earned both his Bachelor of Science in Exercise Science and Bachelor of Business Administration in Finance from Eastern Michigan University where he graduated Cum Laude. While there, he served as President of the Exercise Science Organization and Chemistry Club while pursuing clinical research within the Sports Medicine Department.

After receiving his Doctor of Osteopathic Medicine from Michigan State University, Dr. Zuziak completed a residency in Physical Medicine and Rehabilitation at Mercy Medical Center in New York. He presided as Chief Resident for two terms, worked to create the programs first medical administration rotation with the Chief Medical Officer and assisted in successfully leading his program through ACGME accreditation and CLER site visits.

Dr. Zuziak is a native of Michigan and in his leisure time enjoys music, travel, cuisine, scuba diving, hockey and hiking with his Siberian Husky.

Elizabeth Kloska Kearney, Chief Nursing Officer

Liz has more than 40 years of experience in nursing and management. She has been the CNO of RHNI since the hospital opened in 2020. Liz is committed to providing excellent outcomes for our patients and high engagement levels for every team member. Liz believes that each member of our team is essential to the success of our patients.

Liz earned her Bachelor of Arts in Psychology and Bachelor of Science in Nursing from Saint Mary’s College, Notre Dame, IN. She received her Master of Nursing degree from Ball State University, Muncie, IN. Liz is certified in both Critical Care nursing and Rehabilitation nursing (CCRN-K, CRRN). She is a member of the American Nurses Association, the Indiana State Nurses Association, the American Association of Critical Care Nurses, and the Association of Rehabilitation Nurses.

Liz loves to spend time with her ever-growing family. She also loves to travel and explore new locations with her husband of 40 years, Kevin. Liz is an active community volunteer, serving those with food insecurity and financial challenges through the Saint Vincent de Paul Society. Her most important title is “Gma-Lizzy” the name her grandchildren call her.

Trenton Shoda, PharmD, Director of Pharmacy

Trenton attended Purdue University earning his Doctor of Pharmacy degree in 2015.  He has 7 years of leadership experience and 10 years of experience within the pharmacy profession including retail, long-term care, and hospital.  His passion for leadership stems from his dedication to providing excellent care for every patient.  He loves spending time with his three boys and wife of 6 years whether that be playing outside or a weekend trip to a favorite destination.

To him there is nothing more important than family.

Renee Spanburg, PT, Director of Case Management and Patient Outcomes

Renee provides on going support and leadership for the case management team during a patient’s stay as they plan toward discharge. Her team’s goal is to discharge all patients back home with the necessary equipment and family training.

Renee earned a Physical Therapy degree from Indiana University and has worked in rehabilitation for the past 28 years. She has a wide variety of clinical and operational experience in both inpatient and outpatient rehabilitation.

Renee and her family recently relocated back to South Bend which is her hometown. She has 2 kids that are college students and a wonderful husband of 22 years. She enjoys watching ND football and spending time with her extended family.

Robert Heritz, DPT, DTO

Robert attended Trine University, Fort Wane IN, earning his Doctorate of Physical Therapy degree in 2018. He has over 5 years experience as a practicing therapist in acute care, subacute rehabilitation, and outpatient care with 4 years of leadership experience. He has a passion for patient care and elevating his team to above and beyond quality of care.

Outside of work, he enjoys spending time with his wife and two kids at their family farm in Michigan.

Kristin Williamson, Director of Marketing and Business Development

Kristin comes to the Rehabilitation Hospital of Northern Indiana with over 15 years of experience in healthcare marketing and business strategy. With a passion for improving patient outcomes and enhancing community engagement, she leads innovative marketing initiatives that highlight the hospitals commitment to excellence in rehabilitation services. Kristin holds a bachelor’s degree in marketing and management from Indiana University and is currently working toward her MBA. Kristin is excited to be a part of leading RHNI in its mission to provide compassionate, high-quality care to individuals on their journey to recovery.

Outside of work, Kristin enjoys spending quality time with her husband, Steven. They love traveling, watching IU basketball, and playing with their adorable puppy, Benny.

Tammy Huyvaert, Director of Compliance

I am a Registered Nurse with nearly four decades of experience in healthcare. I began my nursing education with an Associate Degree in Nursing from Southwestern Michigan College, followed by a Bachelor of Science in Nursing from Ferris State University. I later earned a Master of Science in Nursing Education from Western Governors University.

My career has spanned diverse clinical and administrative roles, including 24 years at a local hospital, working with families in organ and tissue donation, and providing compassionate care in hospice settings. Since joining RHNI in April 2025, I have focused on Quality and Compliance, bringing over three years of experience in this area and completing more than 40 hours of specialized training to earn a Compliance Certificate.

Originally from South Bend, Indiana, I value family deeply. My husband, Dennis, and I enjoy spending time with our two grown, married sons, our grandchild, and exploring wineries throughout Indiana and during our travels. I am passionate about upholding the highest standards of care and integrity—always striving to do the right thing for the right reasons on behalf of our patients.

Melissa Saylor, Human Resources Director

Melissa has been in HR for over 25 years. She comes to RHNI after being an HR Director for over 10 years in Charter Schools all across NE Ohio. She is a new resident of Indiana and is excited to be part of an amazing team and committed to upholding the company’s Guiding Principles. Melissa has been a member of SHRM for over 10 years and loves learning new things related to HR, to help her be the best HR director she can be.

Melissa was born and raised in Canton, Ohio. Melissa became an amputee in 2022 and has not let that stop her in anything she does. Outside of work she loves spending time with her family and friends. She enjoys spending time with her partner Brandi exploring and having new adventures.