What's Up With Lisfranc Injuries in the NFL?

EAST RUTHERFORD, NJ - SEPTEMBER 30:  Santonio Holmes #10 of the New York Jets is carted off the field in the second half agai
EAST RUTHERFORD, NJ - SEPTEMBER 30: Santonio Holmes #10 of the New York Jets is carted off the field in the second half against the San Francisco 49ers on September 30, 2012 at MetLife Stadium in East Rutherford, New Jersey.The San Francisco 49ers defeated the New York Jets 34-0. (Photo by Elsa/Getty Images)

Santonio Holmes, Jets wide receiver, Cedric Benson, running back for Green Bay and Carolina center, Ryan Kalil all have something unfortunate in common; they recently suffered Lisfranc injuries. Mike Freeman wrote for the NFL Insider, that though some believe the prevalence of the injury may be increasing due to the ever-increasing speed of the game coupled with the size of the players, he feels, as do others, that it is simply a coincidence.

Freeman quoted Benjamin Wedro, a physician who writes extensively about sports issues, and who referred to the mechanism of Lisfranc injuries as resulting from a "low-energy" trauma where "a twist to the midfoot is added to a fall where the foot is plantar-flexed, or positioned like a ballerina on point." Wedro commented that this often occurs "in a pile-up if the foot is twisted when another player stumbles over top of it." It can also be a result of a foot being stepped on and torqued, particularly as a player tries to free the foot.

What is the Lisfranc Joint?
The midfoot joint complex formed between the metatarsals (the long bones of the midfoot) and the tarsals -- the smaller bones closer to the heel) are also known as Lisfranc's joint. A simple diagram of the area can be viewed here.

So, what exactly is a Lisfranc injury and why is this area particularly vulnerable?
The foot has many unique properties, one of which is that there are no ligaments connecting the base of the first and second metatarsals -- the innermost of the five long bones in the midfoot. The configuration and tight fit of these bones is what substitutes for the ligaments in providing stability, thereby preventing side-to-side movement or dislocation of the bones in this region. That is unless the second metatarsal (which is generally the longest) is fractured -- generally at or near it's base. This is an area where the midfoot is rather vulnerable. With fracture, the other inter-metarsal joints may become dislocated (completely separated from each other).

Though it does not simply connect one bone to another, the primary stabilizer of the joint between the base of the first and second metatarsals is Lisfranc's ligament, which is a strong fibrous tissue that extends from the bottom of the foot at a bone closer to the heel (the medial, or innermost cuneiform -- a tarsal bone) and runs diagonally to the bottom of the inner aspect of the second metatarsal. In addition to also connecting the lateral (outer) metatarsals to the cuneiforms, Lisfranc's ligament contributes to the bony stability of the region at the base of the second metatarsal. Because the dorsal (upper) aspect of Lisfranc's joint lacks this stabilizing support, dislocation often occurs in this direction. However, there are many variations, some with the occurrence of associated injuries to the foot.

Disruption of Lisfranc's ligament may be mild, and therefore treated with immobilization. In the event of fracture with more significant separation, immobilization also follows either closed positioning (reduction) of the bones with percutaneous pinning (from outside the foot to within), or internal fixation with pins placed entirely within the foot. Considerable separation of the bones in the region (greater than 2 mm. of displacement and 15 degrees of tarso-metatarsal separation) requires operative care. See this link for post-operative photos.

It is thought that Lisfranc injuries without fracture are likely to have worse outcomes, with the possibility of later midfoot collapse or metatarsalgia (inflammation of the region)... A reason to be more encouraged by the long-term prospects faced by the player who is out for the season after surgery (like Holmes) than one who escapes the scalpel.

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