Spine Service, spine, vertebra, cervical spine, Han Jo Kim MD,C1-2 fusion, atlantoaxial fusion, atlantoaxial instability, C1 and C2 fixation techniques, HSS, HSS education Institute, Orthopaedics, hospital for special surgery, orthopedic hospital, education institute, orthopedic medical education, free orthopedic education, HSS orthopedic education, HSS resident education, online orthopedic education, orthopedic continuing education, orthopaedic online education, modern fixation
