The Lis Franc's
joint is a combination of joints in the middle of the foot. At the point where
the long bones behind the toes, called metatarsals, connect with a grouping of
small cube shaped bones, called cuneiform bones, there are several joints the
move together in an interlocking fashion. This grouping of interlocking joints
is referred to as the Lis Franc's joint. The Lis Francís joint are bound
together by a series of transverse ligaments on the top and bottom of the joint,
as well as an intermetatarsal ligament. This grouping of joints is clinically
called the tarsometatarsal joints. Fracture-dislocations of the tarsometatarsal
joint are named for Lis Franc who was a field surgeon in the Napoleonic army.
Fracture-dislocations of the tarsometatarsal joint (Lis Francís) is extremely
significant in that it is a commonly missed diagnoses with a great potential
for long term disability.
fracture-dislocations can occur in many different ways. It can be caused by both
a direct crushing type injury or a force applied to the metatarsal heads (ball
of the foot) which both can result in displacement of the Lis Francís joint or
fractures that in involve the joint. Common causes are motor vehicle accidents,
falls from heights, severe foot and ankle sprains, crushing force to the top of
the foot. These injuries can occur during strenuous and competitive athletic
activities. The athlete who complains of sudden onset of pain, in the middle of
the foot during the course of an athletic event should be carefully evaluated
for a possible Lis Franc's injury.
extremely important following the injury. Early diagnosis and treatment can
prevent long-term chronic pain and other sequalae. Diagnosis is made by both clinical
and X-ray modalities. On physical examination there is marked tenderness across
the tarsometatarsal joint usually with pinpoint tenderness at the articulation
of the second metatarsal base and the medial and intermediate cuneiforms.
Global forefoot and midfoot swelling is commonly seen from several minutes to
several hours following injury. In severe dislocations it is very easy to
visualize a change in shape of the foot as compared to the other foot. X-rays
may reveal either a partial or total dislocation at the tarsometatarsal joint.
The difficult cases to diagnosis are those when the joint dislocates and then
relocates on its own. When this occurs there may be little evidence of the
injury on an x-ray. If there are no X-ray changes and clinical diagnosis makes
the doctor suspicious of injury, they may order stress X-ray, bone scan or MRI.
In all acute injuries circulation must be monitored to assess the possibility
of compartment syndrome (increase in pressures within the foot which can shut
off circulation). This could result in loss of oxygen to the tissues, which
might result in loss of the foot.
should always be attempted in an acute fracture-dislocation. Treatment involves
general anesthesia to relax the patient and an attempted reduction of the
second metatarsal base into its anatomic position is attempted. If the second
metatarsal can be reduced then metatarsals two through five may reduce without
much manipulation. If closed reduction is successful then reduction of the
first metatarsal cuneiform joint is performed and pins are inserted to allow
for stability during healing. If closed reduction fails it is usually due to
one of the foot tendons, which may be caught in the dislocated joint. If closed
reduction fails in an acute injury or the injury is old then open reduction
must be performed to reduce long-term problems. If vascular compromise is
evident this also constitutes a need for immediate surgery. There are usually
two to three incisions placed on the top of the foot to allow for adequate
visualization and manipulation of the bones. Once the foot has been placed back
into anatomic position the tarsometatarsal joint is stabilized with either pins
or screws to allow for stability during the healing process. If pins are used
they are usually removed in six to eight weeks. Whether pins or screws are used
doesnít really matter as he patient is non-weight bearing for six weeks and is
usually casted for at least eight to twelve weeks. Following bony healing and
return to ambulation the patient will need a good functional foot orthotic to
provide support and relieve stress from the tarsometatarsal joints and assist
in pain free ambulation. Long-term prognosis for this injury is guarded. When
any injury involves a joint the likelihood of an on-going arthritic process is
likely. In sever cases fusion of the joints may be necessary. In the athlete
this injury can be devastating. Rehabilitation to return to the same level of
performance can takes several months or longer.