- Avascular Necrosis of Femoral Head:
- Blood Supply to Femoral Head & Neck:
- Non-Union following Femoral Neck Frx;
- when femoral neck frx occurs, intraosseous cervical vessels are disrupted;
- incidence of AVN in undisplaced fractures is 11%;
- only 1/3 of patients with AVN will require additional surgery where as 3/4 patients with non union will require reoperation;
- risk of AVN generally corresponds to degree of displacement of the fracture of the femoral neck on the initial radiographs;
- minimally displaced femoral-neck frx:
- is at low risk (< 10%) for osteonecrosis if displacement of the fracture remains unchanged;
- displaced frx:
- incidence of AVN following hip frx is may be > 80% in displaced frx;
- most of retinacular vessels are disrupted;
- femoral head nutrition is then dependent on remaining retinacular vessels and those functioning vessels in the ligamentum teres;
- positioned achieved at reduction is significant factor in development of AVN & subsequent late segmental collapse;
- valgus & rotatory malposition are known to affect foveal blood supply;
- nails in superior (or lateral) aspect of femoral head can inadvertently interrupt lateral epiphyseal vessels that supply most of blood to the femoral head;
- whether early hip joint capsulotomy might reduce the incidence of AVN remains controverisal;
- timing of surgical fixation:
- it remains controversial as to whether early fixation of femoral neck frx will decrease risk of AVN;
- Avoidance of avascular necrosis of the femoral head, following fractures of the femoral neck, by early reduction and internal fixation.
- Delayed internal fixation of fractures of the neck of the femur in young adults. A prospective, randimsed study comparing closed and open reduction.
- Delayed fixation of displaced femoral neck fractures in younger adults.
Avascular Necrosis of the Femoral Head After Osteosynthesis of Femoral Neck Fracture
Avascular femoral head necrosis following fracture fixation.
The effect of femoral neck fractures on femoral head blood flow.
Fracture of the femoral neck. II. Relative importance of primary vascular damage and surgical procedure for the development of necrosis of the femoral head.
Femoral head preservation following subcapital fracture of the femur.
The effect of age on bone composition and viability in the femoral head.
Long-term outcome of patients with avascular necrosis, after internal fixation of femoral neck fractures.
Operative treatment of femoral neck fractures in patients between the ages of fifteen and fifty years.
Avascular necrosis after internal fixation of intracapsular hip fractures; a study of the outcome for 1023 patients.