1501 Waldron Road, Suite 202, Fort Smith, AR 72903 map. Call for an Appointment. Johnson Regional Medical Center. 1000 E Poplar Street, Clarksville, AR 72830 map. Call for an Appointment. Dr. Russell Branum is a rheumatologist in Fort Smith, AR. He treats disorders affecting the joints, muscles and bones (and may also involve other organ systems)..