5th Metatarsal Fx

 

Stress Fracture:

  1.   Fx distal to the ligaments which firmly bind the 4th and 5th metatarsals together

  2.   May be symptomatic before radiographic evidence of fx

  3.   Atheletic pt may benefit from ORIF  (closed treatment rate of non union is 50%)

  4.   If non union has developed, cast immobilization is unlikely to be successful -- consider bone-grafting & internal fixation w/ compression screw


Jones Fracture:

  1.   Fx at base of fifth MT at metaphyseal-diaphyseal junction

  2. , Extends into the 4-5 intermetatarsal facet.

  3.   Located w/in 1.5 cm distal to tuberosity of 5th metatarsal

  4.   Non Operative Treatment:  reserved only for acute fxs (in most cases);

  5.   Minimally displaced, < 3 months old, no evidence of non-union

  6.   Up to 2/3 of these fractures should heal

  7.   Non-wt-bearing cast for 6-8 wks is necessary for healing;

  8.   Surgical Treatment: not meeting above criteria


Avulsion Fracture:

  1.   Extends to the metatarsal cuboid joint or proximal

  2.   Most common fr of the base of the 5th MT (over 90%);

  3.   May be due to pull of the lateral cord of the plantar aponeurosis

  4.   Operative Treatment indicated only for displaced or very large avulsion fx, which extend into the cuboid-metatarsal joints;