What is a Midfoot Sprain?
A midfoot sprain is an injury to the ligaments of the central region of the foot, known as the midfoot. It is a common injury that occurs during athletics, in particular those sports where there is cutting and twisting that can lead to this injury. It can cause an athlete to miss considerable time from his or her season.
Who gets a midfoot sprain?
Midfoot sprains can occur in many sports, but typically occur in those that risk the athlete’s foot to a twisting injury. The most common sport for this to occur in would be football, however athletes in soccer, basketball, field hockey and many others can sustain these injuries. Also, those unique sports in which the foot is locked into a position place the midfoot at risk of an injury. As noted above, these can equestrian sports, windsurfing, and pedaling sports.
What is the relevant anatomy of a midfoot sprain?
The human foot is a highly complex structure made up of 26 separate bones and 33 joints to go along with numerous muscles, tendons, nerves and blood vessels. The structure of the foot is such that there are 2 different arches: a longitudinal (lengthways) and transverse (across the middle of the foot). They are formed by the shapes of the bones themselves and are held in place by the plantar fascia, a tough ligament on the bottom of the foot which attaches to the heel bone (calcaneus) on one end and the toes on the other. The plantar fascia maintains the shape of the arch with a “windlass mechanism” like that of a sail where each end is fixed and the sail itself forms an arch shape in the wind.
The foot is divided into 3 regions a forefoot (front- toes), a midfoot (middle) and a hindfoot (back – ankle and heel regions). The midfoot is comprised of five small bones including the 3 cuneiforms, navicular and cuboid. There is a highly complex system of ligaments attaching each of these bones to one another and also to the forefoot and hindfoot. The midfoot is located in the middle of both the transverse and longitudinal arches and forms the apex of each arch. A midfoot sprain can refer to a stretch injury to any of these ligaments.
How do you diagnose a midfoot sprain?
An athlete with a midfoot sprain will have sustained a twisting or pivoting injury to his or her foot. They will develop immediate pain and later swelling in the central region of their foot. The swelling often can lead to bruising on either the top or bottom or the foot. How much swelling and subsequent bruising occurs is related to how severe the injury is. The athlete will also complain of pain with bearing weight. In milder injuries they will be able to walk without too much pain, but the higher demands on the foot in athletics will be painful. On the other end of the spectrum, in more severe injuries, the injured athlete may not be able to bear any weight even to walk.
On physical examination, the injured foot will look swollen and be tender over the injured joints. It’s important that the examining physician localize the injury to the specific joints involved. The tendons of the foot should remain intact in a midfoot sprain, however their motion may produce pain in the foot if they place stress on the injured joints with motion.
When is advanced imaging needed for a midfoot sprain?
As in most acute injuries, plain radiographs are important to obtain of the foot in different planes. The xrays should be taken with the patient standing and bearing weight if possible. In an injury where a ligament, or ligaments, rupture completely the athlete’s body weight may cause certain bones of the foot to space further apart on the weight-bearing radiographs which not be apart on the xrays without any pressure. This would be indicative of a more severe injury where the injured ligaments are no longer tethered to different bones on either end, therefore the person’s weight can separate them apart. The integrity of the arches of the foot can also be evaluated on these xrays. Sometimes in more severe injuries, the athlete may be too painful to stand for the xrays. In these circumstances, stress xrays where the examiner gently turns the foot to recreate the initial injury can be taken to see if the bones separate.
If there is a suspicion for a more severe injury, an MRI, ultrasound or CT scan may be obtained. The MRI gives the greatest detail of the injured ligaments as it is a good test to evaluate soft-tissues. The ultrasound is an easy test to evaluate the amount of separation between the bones and therefore the integrity of the injured ligaments, but is only available when a specially trained musculoskeletal radiologist is present. The CT scan is useful if there is a suspicion that the injured ligament may have pulled off a small piece of bone at one of its ends as in a Lisfranc injury. The CT scan is the best test to see bone in great detail.
How do you classify a midfoot sprain?
Midfoot sprains are most commonly a momentary stretch of a ligament that subsequently recoils to its original length and is therefore a grade 1 injury. More severe, and less common, injuries may cause a partial (grade 2) or complete (grade 3) ligament rupture. In these cases, the injury is more severe as the ligament does not return to its original length, and the bones it holds together can separate. This is the definition of an unstable injury that usually requires a surgery to repair.
How is a midfoot sprain treated?
A mild, grade 1, midfoot sprain can be managed non-operatively with a short period of immobilization in a hard-soled shoe or a removable boot. A short period of limited weight-bearing may be necessary to allow the ligament to heal and therefore the swelling and pain to subside. Regular icing, elevation and non-steroidal anti-inflammatory medications (NSAIDS) are both important to treat the swelling along with the pain. In most of these cases, the athlete will be able to return to participating in their sport in anywhere from a week to a few months.
More Information: Read about sports injury treatment using the P.R.I.C.E. principle - Protection, Rest, Icing, Compression, Elevation.
When is surgery necessary for a midfoot sprain?
Rarely, a more severe injury will be unstable and the injured ligament will not be able to hold together the bones as it normally does. In this situation, a surgical repair of the injured ligaments is necessary to avoid chronic pain, swelling and the later development of arthritis. A Lisfranc ligament tear is an example of this type of injury.
Surgery in most cases involves a small incision on the top of the foot over the region between the two bones held together by the injured ligament. This is often necessary to be sure the bones are appropriately together (reduced) by direct visualization. The bones are then held together by metal screws or wires in their original position as they were prior to injury. This allows the injured ligament to heal to its original length. Because the bones of the midfoot have a lot of force transmitted through them during walking and even more during athletics, there is small repetitive motion between them with every step. Therefore, the treating surgeon may elect to remove the screws or wires months after surgery to avoid their breaking in the same mechanism as a paperclip that is bent back and forth repetitively.
What happens after surgery for a midfoot sprain?
After surgery for a severe midfoot sprain, the patient will need to have their foot immobilized for a period of time in a splint, cast or boot. They will also, in most cases, need to be limited in the weight-bearing through their foot. The usual time to recovery from this type of injury can take 4 to 6 months, or longer, till an athlete is back to full sports participation.
If you suspect that you have a midfoot sprain, it is critical to seek the urgent consultation of a local sports injuries doctor for appropriate care. To locate a top doctor or physical therapist in your area, please visit our Find a Sports Medicine Doctor or Physical Therapist Near You section.
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