An orthopedic surgeon deals with issues related to your musculoskeletal systems which include your muscles, ligaments, bones, joints, nerves, and tendons. Fractures, osteoarthritis, rheumatoid arthritis, joint dislocation, stiffness, cervical spondylosis, lumbar spondylosis, gout, sprains, sacroiliitis, infections, tumors, osteoporosis, rickets, osteomalacia and musculoskeletal deformities which may be from birth or after birth are some of the common problems which affect the musculoskeletal system. Any illness which affects your musculoskeletal system affects your ability to move i.e. mobility.