anatomy
Last reviewed 01/2018
Femoral neck fractures are intracapsular and may threaten any or all of the three sources of blood to the femoral head:
- the cervical vessels in the retinaculum of the joint capsule - usually damaged if the fracture is displaced
- intramedullary vessels - always torn
- from the ligamentum teres - usually contributes minimally in the elderly and not uncommonly, may be non-existent
In addition to the damage to the blood supply, the intracapsular nature of the fracture hinders recovery from the injury:
- intra-articular bone has only a thin periosteum and has no contact with soft tissues - the response to injury - callus formation - is weak
- blood remains inside the joint capsule, increasing intracapsular pressure and further damaging the femoral head; synovial fluid hinders clotting