| Inbound Relationships | Type | Active | Source | Characteristic | Refinability | Group | 
| Sacral epidural steroid injection | Procedure site | False | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 1 | 
| Therapeutic sacral epidural injection | Procedure site | False | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 3 | 
| Local anesthetic sacral epidural block | Procedure site - Indirect | False | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 1 | 
| Sacral epidural neurolysis | Procedure site - Indirect | False | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 3 | 
| Epidural injection of anesthetic substance, diagnostic, caudal, continuous | Procedure site - Indirect | True | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 1 | 
| Sacral epidural steroid injection | Procedure site - Indirect | True | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 1 | 
| Injection into sacral epidural space | Procedure site - Indirect | False | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 1 | 
| Epidural injection of contrast substance, caudal | Procedure site - Indirect | False | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 1 | 
| Epidural injection of neurolytic solution, caudal | Procedure site - Indirect | False | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 3 | 
| Epidural injection of anesthetic substance, therapeutic, caudal, continuous | Procedure site - Indirect | False | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 2 | 
| Therapeutic sacral epidural injection | Procedure site - Indirect | False | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 1 | 
| Epidural injection of anesthetic substance, therapeutic, caudal, continuous | Procedure site - Direct | False | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 1 | 
| Sacral epidural injection using computed tomography guidance | Procedure site - Indirect | False | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 2 | 
| Epidural injection of contrast substance, caudal | Procedure site - Indirect | True | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 1 | 
| Epidural injection of sacral spine using fluoroscopic guidance | Procedure site - Direct | False | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 1 | 
| Therapeutic sacral epidural injection | Procedure site - Indirect | False | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 1 | 
| Sacral epidural injection using computed tomography guidance | Procedure site - Direct | False | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 1 | 
| Epidural injection of sacral spine using fluoroscopic guidance | Procedure site - Indirect | False | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 2 | 
| Injection into sacral epidural space | Procedure site - Indirect | True | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 1 | 
| Sacral epidural injection using computed tomography guidance | Procedure site - Direct | True | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 1 | 
| Sacral epidural injection using computed tomography guidance | Procedure site - Indirect | True | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 2 | 
| Epidural injection of sacral spine using fluoroscopic guidance | Procedure site - Direct | True | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 1 | 
| Epidural injection of sacral spine using fluoroscopic guidance | Procedure site - Indirect | True | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 2 | 
| Therapeutic sacral epidural injection | Procedure site - Indirect | False | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 1 | 
| Local anesthetic sacral epidural block | Procedure site - Indirect | True | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 1 | 
| Epidural injection of anesthetic substance, therapeutic, caudal, continuous | Procedure site - Indirect | True | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 3 | 
| Entire sacral extradural space | Is a | True | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier |  | 
| Therapeutic sacral epidural injection | Procedure site - Indirect | True | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 2 | 
| Fluoroscopy guided epidural injection of sacral spine | Procedure site - Indirect | False | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 2 | 
| Computerised tomography guided sacral epidural injection (procedure) | Procedure site - Indirect | False | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 3 | 
| Diagnostic caudal epidural bolus injection of anaesthetic substance | Procedure site - Indirect | True | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 1 | 
| Therapeutic caudal epidural bolus injection of anaesthetic substance | Procedure site - Indirect | True | Structure of sacral extradural space | Inferred relationship | Existential restriction modifier | 1 |