RiverRun Ortho North

RiverRun Ortho North provides high-quality surgical orthopaedic care to patients of all ages. Led by one of the top orthopaedic providers in the region, Dr. Mark Sumida, the Ortho North team offers a variety of services, including general and subspecialty orthopaedics, sports medicine, injury care, and more. Our goal is to bring top quality, cutting-edge orthopaedic care to Hixson, treating every patient as if they were our family.



Mark Sumida, MD

Originally from Kentucky, Dr. Mark Sumida entered private practice in Chattanooga in 1995. Dr. Sumida graduated from DePauw University as a prestigious Rector Scholar. He subsequently completed his master's degree in Forensic Science from the University of Alabama in Birmingham. After earning his medical degree from the University of Kentucky in 1988, he completed seven years of surgical training, including one year of general surgery internship and six years of orthopedic surgery residency at the University of Tennessee. He then completed his formal training with a fellowship in orthopedic surgery at Duke University.

Dr. Sumida has been board certified by the American Board of Orthopedic Surgeons since 1996. Nationally, he is a member of numerous professional societies including the American Academy of Orthopedic Surgeons, Piedmont Orthopedic Society, Tennessee Orthopedic Society, and American Academy of Orthopedic Foot and Ankle Surgeons. Throughout his career, he has presented several lectures at national meetings and has published in the orthopedic literature. Dr. Sumida volunteered his time as team physician for the Notre Dame High School football team and served as team doctor for the U.S. National Junior Wildwater Canoe and Kayak Team at the World Championships in the Czech Republic. He has also volunteered his services for every Ironman Triathlon hosted in Chattanooga since its beginnings, including two World Championship Ironman competitions.

For over 15 years he has been a member of the Hamilton County Medical Society. He has served as chairman of numerous committees within the Memorial Healthcare system including Chief of Orthopedic Surgery of Memorial and Memorial Northpark Hospital and currently serves as chairman of the OR Executive Committee of Memorial Northpark Hospital.
In 2021, he joined RiverRun HEALTH. Dr. Sumida's goal is to bring top quality orthopedic surgery to one of Chattanooga's fastest growing communities. He frequently attends national surgical educational meetings. Adhering to the philosophy of treating patients the way we would treat our own family, Dr. Sumida continuously strives to bring cutting-edge technology to the area.


  • Orthopaedic Surgery
  • Specialized Shoulder Surgery
  • Specialized Knee Surgery
  • Joint replacement Surgery [shoulder + knee]
  • Sports Medicine
  • Fracture Care


Joshua Lawson, MD

Dr. Joshua Lawson is a fellowship-trained, board-certified orthopaedic surgeon that treats a variety of adult and pediatric orthopaedic conditions, both operatively and non-operatively, with a special emphasis on hip and knee replacement surgery. He strongly believes in partnering with his patients to develop an individually optimized care plan for each patient.

Dr. Lawson is a native of the Chattanooga area, graduating from Hixson High School in 2005. He attended Lee University on a golf scholarship while earning a bachelor’s degree in Biochemistry. He obtained his medical degree from the University of Tennessee College of Medicine. He completed a 5-year Orthopaedic Surgery residency at the Medical College of Wisconsin in Milwaukee. Prior to starting practice, he completed a fellowship in complex and revision hip and knee replacements under the direction of Dr. Arthur Malkani at the University of Louisville. During his training, he authored nationally published papers and presentations on joint replacement surgery.

During his fellowship year, he received advanced training in MAKO robotic-assisted hip and knee replacements, anterior hip replacements, partial knee replacements, and revision hip and knee replacements. In addition to joint replacements, Dr. Lawson also performs knee arthroscopy as well as fracture care.

Dr. Lawson is an active medical staff member at the Parkridge and Erlanger Health Systems and performs surgery at these locations. He sees patients at both our Riverfront and Hixson clinics.

Dr. Lawson is an active member of several professional organizations, including the American Academy of Orthopaedic Surgeons, American Academy of Hip and Knee Surgeons, International Congress for Joint Reconstruction, and the AO Foundation.

Dr. Lawson and his wife, Haley, who is also a Chattanooga native, are avid golfers and are members at Council Fire Golf Club. They enjoy attending church on Sundays at Calvary Chapel Northside, college football, and spending time with friends and family.


  • Orthopaedic Surgery
  • Hip and Knee Replacement
  • Complex Revision Surgery
  • Specialized Anterior Approach to Hip Replacement
  • Robotic Assisted Knee Replacement
  • Rapid Recovery Outpatient Joint Replacement Surgery


Our Specialties



ACL tears, MCL tears, PCL tears,
meniscus injuries, and degenerative
conditions such as arthritis.



Rotator cuff tears, labral tears,
shoulder impingement, biceps
tears, fractures, and arthritis.



UCL reconstruction (Tommy John
Surgery), ulnar collateral nerve
decompression, elbow fracture repair,
bicep tendon repair (rupture), triceps
tendon repair (rupture), and other surgical
and non-surgical treatment of the elbow.



Fractures, ligament tears, tendonitis,
carpal tunnel syndrome, nerve
compression, tendonitis, and more.



Labral tears, hip impingement,
trochanteric bursitis, arthritis, hip
replacement (arthritis), and



Achilles repair (rupture), ankle joint
instability, bunionectomy, tendon repairs
and transposition, joint replacement, and
fusion (arthritis).


Patient Resources

For your convenience, we include online access to our appointment forms and secure portal, where you can pay your bill, communicate with your provider, access appointment notes, and more.

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