| Inbound Relationships | Type | Active | Source | Characteristic | Refinability | Group | 
| Entire axis vertebra | Is a | False | Bone structure of axis | Inferred relationship | Existential restriction modifier |  | 
| Entire body of axis | Is a | False | Bone structure of axis | Inferred relationship | Existential restriction modifier |  | 
| Structure of lamina of axis | Is a | False | Bone structure of axis | Inferred relationship | Existential restriction modifier |  | 
| Structure of dorsal arch of axis | Is a | True | Bone structure of axis | Inferred relationship | Existential restriction modifier |  | 
| Structure of pedicle of axis | Is a | False | Bone structure of axis | Inferred relationship | Existential restriction modifier |  | 
| Structure of articular facet of axis | Is a | False | Bone structure of axis | Inferred relationship | Existential restriction modifier |  | 
| Structure of process of axis | Is a | True | Bone structure of axis | Inferred relationship | Existential restriction modifier |  | 
| Structure of foramen of axis | Is a | True | Bone structure of axis | Inferred relationship | Existential restriction modifier |  | 
| Structure of articular process of axis | Is a | False | Bone structure of axis | Inferred relationship | Existential restriction modifier |  | 
| Closed fracture axis, posterior arch | Finding site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 2 | 
| Closed fracture axis, tricolumnar | Finding site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Open fracture axis, tricolumnar | Finding site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Closed fracture axis | Finding site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Open fracture axis | Finding site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Spinal fusion of atlas-axis for pseudoarthrosis | Procedure site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Closed fracture of second cervical vertebra without spinal cord injury | Finding site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Arthrodesis by posterior technique of atlas-axis with internal fixation | Procedure site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 3 | 
| Open fracture of second cervical vertebra without spinal cord injury | Finding site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Spinal fusion of atlas-axis | Procedure site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 2 | 
| Open dislocation of second cervical vertebra | Finding site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier |  | 
| Closed traumatic dislocation of second cervical vertebra | Finding site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Arthrodesis by posterior technique of atlas-axis with bone graft | Procedure site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Fracture of second cervical vertebra | Finding site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Closed fracture of axis without spinal cord lesion | Finding site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Open fracture of axis without spinal cord lesion | Finding site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Closed fracture axis, transverse process | Finding site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 2 | 
| Closed fracture axis, spondylolysis | Finding site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Open fracture axis, spondylolysis | Finding site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Arthrodesis by posterior technique of atlas-axis with bone graft | Procedure site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 2 | 
| Arthrodesis by posterior technique of atlas-axis with bone graft | Procedure site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 2 | 
| Arthrodesis by anterior transoral technique, clivus-C1-C2, with bone graft and excision of odontoid process | Procedure site - Indirect | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 2 | 
| Arthrodesis by anterior extraoral technique, clivus-C1-C2, with bone graft and excision of odontoid process | Procedure site - Indirect | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 2 | 
| Arthrodesis by posterior technique of atlas-axis with bone graft | Procedure site - Indirect | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 2 | 
| Structure of body of axis | Is a | True | Bone structure of axis | Inferred relationship | Existential restriction modifier |  | 
| Transoral fusion of atlantoaxial joint | Procedure site - Direct | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 3 | 
| Posterior fusion of atlantoaxial joint | Procedure site - Direct | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 3 | 
| Spinal fusion of atlas-axis for pseudoarthrosis | Procedure site - Direct | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 2 | 
| Arthrodesis by posterior technique of atlas-axis with internal fixation | Procedure site - Direct | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 2 | 
| Spinal fusion of atlas-axis | Procedure site - Direct | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 2 | 
| Arthrodesis by posterior technique of atlas-axis with bone graft | Procedure site - Direct | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 2 | 
| Fusion of atlantoaxial joint NEC | Procedure site - Direct | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 2 | 
| Open fracture axis, spondylolysis | Finding site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Fracture of second cervical vertebra | Finding site | True | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Closed fracture axis, tricolumnar | Finding site | True | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Open fracture axis, tricolumnar | Finding site | True | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Open fracture of second cervical vertebra without spinal cord injury | Finding site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Closed fracture of second cervical vertebra without spinal cord injury | Finding site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Open fracture axis | Finding site | True | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Closed fracture axis, spondylolysis | Finding site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Closed fracture of axis without spinal cord lesion | Finding site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Open fracture of axis without spinal cord lesion | Finding site | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Closed fracture axis | Finding site | True | Bone structure of axis | Inferred relationship | Existential restriction modifier | 1 | 
| Entire bone of axis | Is a | True | Bone structure of axis | Inferred relationship | Existential restriction modifier |  | 
| Posterior fusion of atlantoaxial joint NEC | Procedure site - Direct | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 3 | 
| Posterior fusion of atlantoaxial joint using transarticular screw | Procedure site - Direct | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 3 | 
| Posterior fusion of atlantoaxial joint using pedicle screw | Procedure site - Direct | False | Bone structure of axis | Inferred relationship | Existential restriction modifier | 3 |