sumit blood supply of head of femur.pptx

femur

1. Blood supply of head of femur in adults and in children Presenter Dr Sumit Moderator Prof Rajiv Kapila

2. Importance of blood supply to femoral head Femoral head relies on a delicate blood supply for viability Disruption of blood supply can lead to Avascular necrosis

3. Blood supply of head of femur in adults

4. Medial femoral circumflex (MFCA): Course: between pectineus and psoas, then posterior to femoral neck under quadratus femoris. Major blood supply to adult femoral head. Major contributor to extracapsular ring / anastomosis

5. Lateral femoral circumflex (LFCA): Course:· Deep to sartorius and rectus femoris. · Ascends anterior femoral neck· Across proximal femur to GT. Under rectus femoris. Less significant blood supply in adult femoral head. At risk in anterolateral approach to hip.

6. Extracapsular ring >Formed at the base of femoral neck primarily from branches of MFCA and LFCA. Lateral branch → from ring laterally toward GT → supply greater trochanter. Ascending cervical arteries → along extracapsular femoral neck →branch from extracapsular ring. Retinacular arteries → along intracapsular femoral neck → intracapsular continuation of cervical arteries from a 2nd intracapsular ring at base of head.

7. Sub synovial intracapsular arterial ring: Formed at the base of the femoral head .Epiphyseal arteries and lateral epiphyseal artery :Enter bone at border of articular surface in posterosuperior neck.>Will form intraosseous anastomoses. Lat. Epiphyseal supplies most of WB femoral head.

8. Obturator Artery: Artery of ligamentum teres -→ Through ligamentum teres to fovea → Minimal supply to the adult femoral head. Medial epiphyseal artery → Interosseous terminal branches → Anastomose with lateral epiphyseal arteries.

9. Paediatric femoral head blood supply:· 0-4yr -→ MFCA, LFCA, and ligamentum teres artery; ·4-8yr: mostly MFCA, minimal LFCA and ligamentum teres artery; · 8yrs:MFCA is predominant.

10. Paediatric femoral head blood supply:· At birth, interosseous continuation of branches of the medial and lateral circumflex arteries (metaphyseal vessels) traversing the femoral neck predominately supply the femoral head. These arteries gradually diminish in size as the cartilaginous physis develops and forms a barrier, preventing trans physeal continuity of these vessels into the femoral head. As a result, the metaphyseal blood supply to the femoral head is virtually nonexistent by age 4.

11. Paediatric femoral head blood supply When the metaphyseal vessels diminish, the intracapsular lateral epiphyseal vessels predominate and the femoral head is primarily supplied by these vessels . The lateral epiphyseal vessels extend superiorly on the exterior of the neck, bypassing the physeal barrier, and continuing into the epiphysis.

12. The vessels of the ligamentum teres are of virtually no importance.".A thorough understanding of the vascular anatomy of the femoral head is needed for understanding pediatric hip fractures, The multiple small vessels of the young coalesce with age to a limited number of larger vessels. As a result, damage to a single vessel can have serious consequences; for example, occlusion of the posterosuperior branch of the medial circumflex artery can cause ON of the anterior lateral portion of the femoral head.

13. It is also important for surgeons to recognize where capsulotomy should be performed todecrease iatrogenic injury to existing blood supply. It is suspected that anterior capsulotomy does not damage the blood supply to the femoral head as long as the intertrochanteric notch and the superior lateral ascending cervical vessels are avoided.

14. Paediatric neck femur classification

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16. What causes AVN Direct vascular injury with tearing of retincular vessels # displacement ( causing kinking of vessels ) joint haemarthrosis ( tamponade effect ) # instability ( causes further damage to vasculature )

17. Thank you