- Discussion:
- least common pediatric femoral neck frx (about 7%);
- capital femoral epiphysis may stay w/in acetabulum but in 50% of cases the capital fragment is dislocated;
- tends to occur in infants and young children;
- this injury may be the result of a difficult delivery;
- look for pseudoparalysis as well as shorteing, flexion, and external rotation of the extremity;
- ultrasound may help make the diagnosis;
- diff dx includes a
septic hip;
- w/ this injury,
blood vessels to femoral head are usually damaged, there is & a high
incidence of avascular necrosis (upto 100 %)
- growth arrest in epiphysis can cause shortening of upto 15% (see
growth deformities);
- valgus or varus angulation of femoral neck can occur from arrest of only one side of the epiphyseal plate;
- Treatment:
- indications for preoperative hip aspiration (or
intra-operative capsulotomy) remain unclear;
-
young children:
- smooth pins are inserted across the epiphysis in most cases;
- problem: smooth pins do not back out with collapse at frx site (as do threaded pins)
and may penetrate into acetabulum;
- thread pins may damage physis and cause partial growth arrest, and therefore are usually avoided;
- one solution is to use pins which are smooth at the tips but are threaded in the midshaft;
-
adolescents:
-
cannulated screws;
Transepiphyseal fractures of the neck of the femur in very young children.
E. Forlin et al. JPO. vol 12(2) 1992. p 164-168.
