Metatarsals 1

Metatarsals 1
Metatarsals

Reference: Heckmann, James, in Rockwood and Green, 1996, Chapter 32

Main Message

The first MT is the most important, and needs to be treated with some caution. Lookout for sagittal deformity – these can cause pressure problems on the sole of the foot..

Points of Interest

– be careful to look at the entire foot!
– nondisplaced and minimally displaced shaft and neck fractures can be treated in a walking cast 2-4 weeks, with emphasis on early ambulation as soon as tolerated.
* if walking cast is chosen, the patient should be kept in a cast for as short a time as possible (2-3 weeks) and then encouraged to ambulate in a well padded shoe
– displacement in the frontal plane of the 2nd, 3rd, and 4th MTs is well tolerated. In the 1st and 5th there may be bony prominences that give problems, so this needs to be watched for. Sagittal plane displacement, however , is not well tolerated.
– reduction of sagittal plane deformity can be achieved closed with traction, and if unstable percutaneous pinning can be done
– for 1st MT fractures, these are probably best treated with ORIF and rigid internal fixation – it is more important to get this one perfect and mobilize the patient
– Metatarsal head fractures are often angulated plantarly, and can be fixed with K-wires after reduction

Base of 5th MT Fractures

– the “Jones” Fracture is a fracture of the proximal shaft of the 5th, described by him to be “approximately three quarters of an inch from the fifth metatarsal base”.
– much confusion about what actually constitutes a Jones fracture!

Dameron, Lawrence, Botte – 3 zones:
1. avulsion fractures
2. fracture at the metaphyseal/diaphyseal junction – these are probably representative of the Jones fracture
3. fracture through the proximal 1.5 cm of the shaft

Basically, the Zone 1 injuries give no long term problems; the Zone 2 injuries are similar but take longer to heal, and the Zone 3 injuries are stress fractures that are a major pain in the ass.

Zone 1 – avulsion fracture; interestingly, the avulsion is from the lateral cord of the plantar aponeurosis, not the peroneus brevis, which inserts a bit more distally.
– “regardless of size or degree of displacement, and for all nondisplaced intra-articular fractures, there are few long-term complications, and in most cases, symptomatic treatment alone is indicated.” Treat with 2-3 weeks immobilization in walking cast, then supportive shoe. If persistently symptomatic after nonunion, you can excise it. They do comment that if significant displacement at the cuboid-MT joint exists (in an unusually large fragment), these can be fixed.

Zone 2 – similar to zone 1, but take longer to heal; thus, treat with 6 weeks non-weightbearing cast.

Zone 3 – generally speaking, these are stress fractures
– treat initially with 6 weeks non-weightbearing cast if there is no sclerosis; if
– can be bone grafted and then fixed with compression screw fixation
– for obvious nonunion with sclerosis – bone graft

Metatarsophalangeal Joint Injuries

First MTP – significant soft tissue restraints
– capsule, lateral/medial collateral ligaments
– EHL expansion dorsally
– volar plate, FHL, FHB, conjoined tendon of FHB and Abductor Hallucis, conjoined tendon of FHB and adductor.

Sprains are “turf toe” from persistent hyperextension
– Dislocations are rare, and may be “complex” in that the reduction is blocked by the FHB tendons and the capsule, where traction causes a “Chinese Finger Trap” scenario;
– seeing unfractured sesamoids should alert to the potential of being irreducible
– these can be reduced through a dorsal incision

Sesamoid Fractures

– the medial is more commonly fractured than the lateral
– initial treatment is in walking cast for 3-4 weeks, then a stiff soled shoe
– excision only if persistently symptomatic.
– the medial one is approached from the medial aspect of the 1st ray; the lateral is excised through a dorsal first web space incision

Fractures of the Great Toe

– nondisplaced