- See:
-
x-rays for femoral neck fractures:
-
technique of closed reduction:
- Acceptable Reduction:
- poor reduction of femoral neck frx interferes w/
blood supply to femoral head
& decreases apposition of bone between bone fragments;
- reduction should leave neck-shaft angle between 130-150 degrees;
- radiographic outline of femoral head & neck junction will have convex outline of
femoral head meeting concave outline of femoral neck regardless on all views;
- this outline produces image of S or reversed S curve;
- hence, if outline reveals an unbroken C curve, then frx is not reduced;
- posterior comminution: have higher occurance of
non-union;
-
garden's alignment index:
-
valgus reduction:
- reduction should leave neck-shaft angle between 130-150 degrees;
- acceptable reduction may have up to 15 deg of valgus angulation;
- valgus reduction will increase bony stability, esp in pts w/ posterior comminution;
- excessive valgus (
> 185 deg - Garden angle ) may increase rate of
AVN (due to tethering of lateral epiphyseal vessels);
- valgus position can be reduced by decreasing traction;
-
varus reduction:
- results in an increased
non-union rate;
- if reduction is in varus, more traction must be applied, & greater trochanter is pushed medially w/
heel of hand to adduct shaft in relation to head;
- this will increase valgus position & impact frx at same time;
- as noted by Weinrobe et al (Jan 1998), major relative risk of redisplacement of femoral neck
fractures correlates with initial inferior fracture offset and varus angulation;
- the take home message is that a non anatomic reduction will often lead to postoperative displacement;
- similar findings were published by Chua et al 1998, who noted that varus angulation was the biggest predictor
of early fixation failure;
-
angulation: (anteversion)
- reduction should be between
0 - 15 degrees of anteversion;
- anterior or posterior angulation of > than 10 degrees should not be accepted, particularly in osteoporotic bone;
-
apex anterior angulation: (retroversion)
- internal rotation & adduction oppose fracture surfaces & correct apex anterior angulation on lateral view;
- posterior angulation or retroversion can be corrected by posterior directed force applied to anterior aspect of femoral shaft;
Predictors of early failure of fixation in the treatment of displaced subcapital hip fractures.
D Chua et al.
J Orthop Trauma.
Vol 12. No 4. p 230-234. 1998.
