Fractures and dislocations of the foot 2
base of the second metatarsal. Note that there lacks such strong reinforcement between the first and second metatarsal bases, making this an area of instability.
– the key radiographic landmarks are: congruity from the medial border of the 2nd metatarsal and the medial border of the middle cuneiform; and congruity from the medial border of the 4th metatarsal and the medial border of the cuboid.
Classification (Quenu, Kuss)
Homolateral – all five metatarsals going in one direction
Isolated – one or two metatarsals
Divergent – usually between the first and second metatarsals
– needs careful clinical examination: these dislocations may reduce and look okay on xray, so you may overlook the severity of the injury
– look for pain on passive supination/pronation of the foot.
– on xray, fractures of the navicular, cuboid, cuneiforms, or of the metatarsal bases (particularly the second metatarsal) should make your suspicion increase.
– some authors have recommended cast treatment if the joint is reduced. Others suggest that the reduction can be lost when the swelling subsides and recommend fixing them
– it would appear that the most reliable way to treat these is to fix them; certainly, any displacement warrants reduction and stabilization
– Myerson’s guidelines – ORIF if >2mm displacement or a talometatarsal angle of > 15o.
– ORIF can be done through a dorsal longitudinal incision over the 1st/2nd interspace – this gives access to the 2nd metatarsal head which is usually the tough one to get reduced. Be aware that an entrapped anterior tibial tendon can block the reduction of the 2nd metatarsal.
– Fixation either with stout K-wires (0.062) or interfrag screw