Arthritis Care Specialists specializes in rheumatology, which is the study and treatment of diseases that affect the joints and connective tissues, such as arthritis. The practice consists of Dr. Paul A. Gertler and Dr. Thomas J. Lang ,who specialize in adult rheumatology, and Dr. Stephen W. George and Dr. Melissa Hawkins-Holt, who specialize in adult and pediatric rheumatology. Dr. Cathy X. Gao is a pain management and rehabilitation expert who also practices with ACS.