7
Elbow
General Knowledge
Anatomy
| 1. | What is the normal elbow carrying angle for males? Females? | 1. | Males: 7 degrees valgus Females: 13 degrees valgus |
| 2. | Through what two anatomic landmarks does the elbow center of rotation pass? | 2. | Centers of trochlea and capitellum Anteroinferior medial epicondyle |
| 3. | Relative to the coronoid, how far distal does the elbow capsule extend? | 3. | 6 mm distal |
| 4. | … does the brachialis insert? | 4. | 11 mm distal |
| 5. | … does the anterior branch of the medial collateral ligament (MCL) insert? | 5. | 18 mm distal |
| 6. | What is the relative distribution of load between the radius and ulna at the wrist? | 6. | 80% radius 20% ulna |
| 7. | … at the elbow? | 7. | 60% radius 40% ulna |
| 8. | Why is there a difference? | 8. | Interosseous membrane |
| 9. | What are the three components of the clinical significance of the anconeus muscle? | 9. | Kocher approach Ulnar nerve compression Posterolateral rotatory instability |
Surgical Approaches to the Elbow
| 10. | For the medial approach to the elbow, what is the proximal interval? | 10. | Brachialis Triceps |
| 11. | What is the distal interval? | 11. | Brachialis Pronator teres |
| 12. | For the anterior approach, what is the interval? | 12. | Brachialis Pronator teres |
| 13. | For what clinical situation is the anterior approach most commonly used? | 13. | Pulseless type III supracondylar fracture |
| 14. | For the anterolateral approach, what is the proximal interval? | 14. | Brachialis Brachioradialis |
| 15. | What is the distal interval? | 15. | Brachioradialis Pronator teres |
| 16. | With this approach, how can the posterior interosseous nerve (PIN) be best protected? | 16. | Supinate the forearm |
| 17. | For the posterolateral approach, what is the interval? | 17. | Anconeus Extensor carpi ulnaris (ECU) |
| 18. | How can the PIN be protected with this approach? | 18. | Pronate the forearm |
| 19. | What approach is best for addressing a capitellar shear fracture? | 19. | Kocher |
Trauma and Instability
Elbow Dislocation and Instability
Elbow Dislocation
| 20. | To reduce a dislocated elbow, in what position should the forearm be held? | 20. | Supination |
| 21. | To maintain postreduction stability, in what position should the forearm be placed? | 21. | Pronated |
| 22. | For how long should the reduced elbow be immobilized? | 22. | Several days |
| 23. | What is the most common complication of a simple elbow dislocation? | 23. | Loss of terminal extension |
Posterolateral Rotatory Instability (PLRI)
| 24. | To test for PLRI, in what position should the elbow be held? | 24. | Hold the elbow supinated |
| 25. | What two loads should be applied? | 25. | Axial Valgus |
| 26. | In an unstable elbow, what happens with extension? With flexion? | 26. | Extension dislocates Flexion reduces |
| 27. | What muscle provides a secondary restraint against PLRI? | 27. | Anconeus |
Complications of Dislocation
| 28. | What percent of simple dislocations develop heterotopic ossification (HO)? | 28. | 3% |
| 29. | What percent of fracture dislocations develop HO? | 29. | 20% |
| 30. | Maximal recovery of motion is expected by what time? | 30. | 6 months |
| 31. | What is the functional elbow flexion-extension range of motion (ROM)? | 31. | 30 to 130 degrees |
| 32. | Indications for elbow contracture release include an elbow ROM of less than ________. | 32. | 40 to 105 degrees |
| 33. | What structure is at risk with contracture release? | 33. | Ulnar nerve |
| 34. | What is the recommended timing of elbow HO resection? | 34. | Within 6 months of fracture |
| 35. | What is the radiographic marker indicating when it is acceptable to excise the HO? | 35. | HO appears mature on plain radiographs |
| 36. | Are additional tests necessary? | 36. | No |
Hinged Elbow Fixators for Instability
| 37. | What are the three indications for applying a hinged fixator to an unstable elbow? | 37. | Persistently unstable despite ligamentous repair Delayed treatment of stiff/dislocated elbow Protect bony open reduction with internal fixation (ORIF) of coronoid, radial head, capitellum |
Elbow Fractures
Distal Humerus
| 38. | In ORIF for diaphyseal distal humeral fractures, in what two ways can the construct torsional stiffness be increased? | 38. | Longer plates and screws Bicortical fixation |
| 39. | What is the treatment for a nondisplaced lateral column distal humerus fracture? | 39. | Cast in supination |
| 40. |
