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Hip and Femur
Hip: General Knowledge
Anatomy
Femoral Head Blood Supply
| 1. | What three vessels comprise the main femoral head blood supply from birth to 4 years? | 1. | Medial femoral circumflex Lateral femoral circumflex Posterior branch of obturator artery (ligamentum teres) |
| 2. | What two vessels comprise the main femoral head blood supply from 4 years to adulthood? What surgical technique may potentially compromise this supply? | 2. | Medial femoral circumflex to lateral epiphyseal artery Piriformis nail may injure blood supply |
| 3. | What vessel comprises the main femoral head blood supply in the adult? | 3. | Medial femoral circumflex to posterosuperior/posteroinferior retinacular arteries |
| 4. | The medial and lateral femoral circumflex vessels are branches of what vessel? | 4. | Profunda femoris |
| 5. | What four vessels contribute to the cruciate anastomosis? Where is the anastomosis found? | 5. | First perforating artery Inferior gluteal artery Medial femoral circumflex Lateral femoral circumflex At inferior edge of quadratus femoris |
Lumbosacral Plexus
| 6. | The lumbosacral plexus is composed of the ventral rami of which roots? | 6. | T12 to S3 |
| 7. | The lumbosacral plexus lies posterior to what structure? | 7. | Psoas |
| 8. | The lumbosacral plexus lies on the surface of what structure? | 8. | Quadratus lumborum |
| 9. | What nerve roots contribute to the femoral nerve? | 9. | L2 to L4 |
| 10. | What nerve roots contribute to the superior gluteal nerve? | 10. | L4 to S1 |
| 11. | What nerve roots contribute to the inferior gluteal nerve? | 11. | L5 to S2 |
| 12. | What nerve roots contribute to the sciatic nerve? | 12. | L4 to S3 |
| 13. | What division of the sciatic nerve is lateral? Why is this important? | 13. | The peroneal division is lateral Most commonly injured |
| 14. | What is the only peroneal division innervated muscle above the knee? | 14. | Short head of biceps |
| 15. | The peroneal nerve runs under what muscle in the thigh? | 15. | Long head of biceps |
| 16. | What two structures exit the greater sciatic foramen (GSF) above the piriformis? | 16. | Superior gluteal artery Superior gluteal nerve |
| 17. | What is the mnemonic for the six structures that exit the GSF below the piriformis? | 17. | POPS IQ Pudendal nerve Nerve to obturator internus Posterior femoral cutaneous nerve Sciatic nerve Inferior gluteal artery and nerve Nerve to quadratus femoris |
| 18. | What three muscles contribute to hip flexion? What is their innervation? | 18. | Iliopsoas Rectus femoris Sartorius Innervation: femoral nerve |
| 19. | What two muscles extend the hip? What is their innervation? | 19. | Gluteus maximus (innervation: inferior gluteal nerve) Hamstrings (innervation: sciatic) |
| 20. | What two muscles abduct the hip? What is their innervation? | 20. | Gluteus medius Gluteus minimus Innervation: superior gluteal nerve |
| 21. | What four muscles adduct the hip? What is their innervation? | 21. | Adductor magnus (innervation: sciatic, posterior branch obturator) Adductor brevis (innervation: posterior branch obturator) Adductor longus (innervation: anterior branch obturator) Gracilis (innervation: anterior branch obturator) |
| 22. | What three nerves supply the external rotators of the hip? | 22. | Nerve to obturator internus Nerve to quadratus femoris Nerve to piriformis |
| 23. | What two structures does the nerve to the obturator internus innervate? | 23. | Obturator internus Superior gemellus |
| 24. | What two structures does the nerve to the quadratus femoris innervate? | 24. | Quadratus femoris Inferior gemellus |
| 25. | What structure does the nerve to the piriformis innervate? | 25. | Piriformis |
| 26. | What innervates the obturator externus? | 26. | Nerve to obturator externus |
| 27. | What muscle is the primary internal rotator of the hip? | 27. | Gluteus medius |
| 28. | Where does the long head of the biceps originate? | 28. | Ischial tuberosity |
| 29. | What is the origin of the short head of the biceps? | 29. | Linea aspera |
| 30. | Between what two structures does the sciatic nerve exit the GSF? | 30. | Piriformis Superior gemellus |
| 31. | What three muscles attach to the anterior superior iliac spine (ASIS)? | 31. | Sartorius Transverse abdominal muscle Internal abdominal muscle |
| 32. | What two structures are attached to the anterior inferior iliac spine (AIIS)? | 32. | Rectus femoris Y ligament of Bigelow |
| 33. | What is the origin of the obturator internus muscle? Through what foramen does it pass? Where does it insert? What vessels lie underneath? | 33. | Origin: internal pelvic wall Passes through lesser sciatic foramen Insertion: medial greater trochanter Obturator artery and nerve underneath |
| 34. | How does the nerve to the obturator internus exit the pelvis? How does it reenter? What else travels this way? | 34. | Exits through greater sciatic foramen Reenters lesser sciatic foramen Pudendal nerve and internal pudendal artery also travel out GSF and in lesser sciatic foramen (LSF) |
| 35. | What separates the greater and lesser sciatic foramina? | 35. | Sacrospinous ligament |
| 36. | How does the obturator nerve exit the pelvis? | 36. | Through the obturator foramen |
| 37. | Between what two structures does the femoral nerve lie? | 37. | Iliacus Psoas |
| 38. | How might a psoas abscess present? What position generally provides relief? | 38. | Psoas abscess may cause femoral or sciatic symptoms Hip flexion may provide temporary relief |
| 39. | What nerve is associated with hip pain referred to the knee? | 39. | Anterior branch of obturator nerve |
Surgical Approaches
Smith-Petersen (Anterior)
| 40. | What is the interval for dissection? | 40. | Sartorius/tensor fascia lata (TFL) |
| 41. | What two structures are at risk? | 41. | Lateral femoral cutaneous nerve Lateral femoral circumflex artery (ascending branch, ligate) |
| 42. | What are two common uses for the Smith-Petersen approach? | 42. | Congenital hip dislocation Hemiarthroplasty |
Watson-Jones (Anterolateral)
| 43. | What is the interval for dissection? | 43. | TFL/gluteus medius |
| 44. | What three structures are at risk? | 44. | Femoral nerve with excessive traction Superior gluteal nerve if >5 cm above acetabulum Lateral femoral circumflex artery (descending branch) |
| 45. | What is the most common use for the Watson-Jones approach? | 45. | Total hip arthroplasty |
Hardinge (Lateral)
| 46. | What is the interval for dissection? | 46. | Split vastus lateralis and gluteus medius (no true plane) |
| 47. | What two structures are at risk? | 47. | Femoral nerve Superior gluteal nerve if >5 cm above acetabulum |
| 48. | What is the most common use for the Hardinge approach? | 48. | Total hip arthroplasty |
| 49. | What are the postoperative total hip precautions for a lateral approach? What approach has the same precautions? | 49. | Avoid excess extension and external rotation Same as for anterior approach |
Medial Approach
| 50. | What is the interval for dissection? | 50. | Adductor longus/gracilis |
| 51. | What three structures are at risk? | 51. | Obturator nerve Medial femoral circumflex artery Deep external pudendal artery |
| 52. | What is the most common use for the medial approach? | 52. | Congenital hip dislocation |
Heterotopic Ossification (HO)
| 53. | What hip approach is most often associated with heterotopic ossification? | 53. | Direct lateral approach |
| 54. | What is the prophylactic radiation dose for HO prevention? Within how many hours must it be administered? | 54. | 700 cGy (centigray) Within 48 hours |
| 55. | What is the recommended indomethacin dose for HO prevention? For how long? | 55. | 75 mg daily For 6 weeks |
| 56. | Have bisphosphonates been shown to be effective in preventing HO? | 56. | No |
Hip: Pathologic States
Avascular Necrosis (AVN)
| 57. | What is the first step in the development of AVN? | 57. | Osteocyte death |
| 58. | What are the next three steps? What stage is weakest and thus most likely to result in collapse? | 58. | Inflammation New woven bone laid onto dead trabeculae Dead trabeculae resorbed and remodeled (weakest stage) |
| 59. | What percentage of AVNs are bilateral? | 59. | 50 to 80% |
| 60. | What Ficat/Steinberg stage corresponds to subchondral collapse? | 60. | III |
| 61. | The Association Research Circulation Osseous (ARCO) classification also classifies AVN progression based on what parameter? | 61. | Percentage of head involvement |
| 62. | What is the radiographic sign of subchondral collapse? What does it actually represent? | 62. | Crescent sign Space between articular surface and subchondral bone |
| 63. | What imaging study has the highest sensitivity and specificity for detecting early AVN? | 63. | Magnetic resonance imaging (MRI) |
| 64. | What is the recommended treatment for pre-collapse AVN? Which patients respond poorly? | 64. | Core decompression Poor response in patients with history of taking steroids |
| 65. | Does a history of steroids adversely affect the outcome of vascularized fibular grafting? | 65. | Steroid history does not worsen outcomes |
| 66. | What are the two principal complications of free fibula graft harvest? | 66. | Sensory deficit Valgus instability |
| 67. | What is the 5-year failure rate after vascularized fibular grafting? | 67. | 33% convert to total hip arthroplasty (THA) in 5 years |
| 68. | What is the maximum percentage of head involvement for consideration of osteotomy? | 68. | 50% |
| 69. | What is the preferred treatment for advanced AVN? What two complications are more likely in AVN patients? | 69. | Total hip arthroplasty Loosening Dislocation |
Transient Osteoporosis of Hip
| 70. | What patients have been classically associated with transient hip osteoporosis? | 70. | Pregnant women |
| 71. | What patient population is actually most commonly affected? | 71. | Young males |
| 72. | What diagnostic imaging modality is safe even in pregnancy? | 72. | MRI |
| 73. | How can transient osteoporosis be differentiated from AVN on MRI? | 73. | Not sharply demarcated like AVN |
| 74. | What does the medical treatment of transient osteoporosis consist of? | 74. | Nonsteroidal antiinflammatory drugs (NSAIDs) |
| 75. | What is the weight-bearing status on the affected extremity? | 75. | Non-weight bearing (NWB) |
| 76. | What is the usual natural history? | 76. | Spontaneous resolution |
Acetabular and Femoral Osteotomies: Adults
| 77. | What are the three general causes of excess femoral anteversion in adults? | 77. | Residual developmental dysplasia of the hip (DDH) Total hip replacement with subsequent HO development (pelvis flexed) Miserable malalignment syndrome |
| 78. | What acetabular osteotomy is preferred for adults? What is the effect on the medial/lateral acetabular position? | 78. | Ganz Medializes the acetabulum |
| 79. | What is an indication for femoral varus derotational osteotomy (VRDO) in an adult? | 79. | Dysplasia with coxa valga |
| 80. | With what percentage of head involvement with AVN should one consider intertrochanteric osteotomy? | 80. | <50% head involvement for osteotomy Varus osteotomy if lateral head intact Valgus osteotomy if medial head intact |
| 81. | After Perthes disease, where does the femoral head generally impinge? What is the treatment? | 81. | Impinges laterally (at osteophyte) Treatment: valgus intertrochanteric osteotomy |
| 82. | What osteotomy is preferred after slipped capital femoral epiphysis (SCFE)? Is there a caveat? | 82. | Valgus flexion osteotomy Caveat: no anterior closing wedge for flexion osteotomy |
Hip Arthroscopy and Femoro-Acetabular Impingement
Hip Arthroscopy
| 83. | The anterior portal for hip arthroscopy lies at the intersection of what two landmarks? | 83. | Vertical line from ASIS Horizontal line from the greater trochanter |
| 84. | What two structures are at risk with the anterior portal? | 84. | Lateral femoral cutaneous nerve Femoral vessels |
| 85. | What other two portals are commonly used and where do they lie? | 85. | Anterolateral portal Posterolateral portal On either side of greater trochanter |
| 86. | What two structures are at risk with the anterolateral portal? | 86. | Superior gluteal nerve Lateral femoral cutaneous nerve |
| 87. | What two structures are at risk with the posterolateral portal? | 87. | Sciatic nerve |
| 88. | What patients are at highest risk for developing labral tears? | 88. | Those with acetabular dysplasia |
Femoro-Acetabular Impingement
| 89. | What is the fundamental problem? How does this relate to acetabular version? | 89. | Anterior over-coverage Excess acetabular retroversion |
| 90. | What is the usual location of the corresponding labral injury? | 90. | Anterosuperior labral tear |
