Treats injuries, diseases, and disorders related to the bones, joints, and musculoskeletal system, including fractures, arthritis, and musculoskeletal pain. What are the most common diseases in orthopedics? Common Orthopedic Disorders Osteoarthritis. Rheumatoid Arthritis. Treatment for Arthritis. Cubital Tunnel Syndrome. Lateral Epicondylitis (Tennis Elbow) Medial Epicondylitis (Golfer's or Baseball Elbow) Carpal Tunnel Syndrome. Ligament Injuries to the Knee. Torn Meniscus.