Tarsometatarsal dislocation may also occur in the diabetic neuropathic joint (Charcot). Plain radiograph/CT These injuries are well demonstrated on the standard views of the foot, but subtle injuries may be missed and require further imaging such as CT, MRI or radiographic stress views with forefoot abduction.
The key finding is misalignment of the second tarsometatarsal joint, such as lateral displacement of the second metatarsal base on AP view and/or dorsal step-off sign on lateral view 10. An additional abnormality is diastase >2 mm between the first and second metatarsal bases 10.
Associated fractures most often occur at the base of the second metatarsal, seen as the fleck sign. MRI Again may be useful for assessing ligamentous injury especially when there is a high clinical concern with routine radiographs being inconclusive 7.
Although conventional radiography can usually demonstrate the features of these complications, CT is the better technique for delineating their details. History and etymology It is named after Jacques Franc De Saint Martin (1790-1847), the chief of surgery at the Hospital de la Pixie in Paris 2.
Gonna RC, Connell DG, Nichols DM. Woodward S, Jacobson JA, Amino JE et-al. Sonographic evaluation of Franc ligament injuries.
McMahon PJ, Deer S, Rankin SM et-al. MRI of injuries to the first interosseous cuneometatarsal (Franc) ligament. Realer KW, Grossman J, Darren B et-al. MR imaging of the tarsometatarsal joint: analysis of injuries in 11 patients.
Jones EA, Man aster BJ, May DA et-al. Neuropathic osteoarthropathy: diagnostic dilemmas and differential diagnosis. Haapamaki VS, Kirk MJ, Tolkien SK.
Sivakumaran BS, An AVG, Ointment C, Myers on M. Subtle Franc Injuries: A Topical Review and Modification of the Classification System. The severity of the injury can vary from simple to complex, involving many joints and bones in the midfoot.
However, injury to the Franc joint is not a simple sprain that should be simply “walked off.” It is a severe injury that may take many months to heal and may require surgery to treat.
The bones are held in place by connective tissues (ligaments) that stretch both across and down the foot. A twisting fall can break or shift (dislocate) these bones out of place.
During walking, the midfoot transfers the forces generated by the calf muscles to the front of the foot. It is named after French surgeon Jacques Franc de St. Martin, who served in the Napoleonic army in the 1800s.
The midfoot will be affected if the bones are broken (fractured) or the ligaments are torn (ruptured). Franc injuries tend to damage the cartilage of the midfoot joints.
If severe midfoot injuries are not treated with surgery, then damage to the cartilage and increased stress at the midfoot joints will result in both collapse of the arch and arthritis, which require complex surgery to correct. Even with successful surgery for the Franc injury, arthritis can still develop in later life.
More severe injuries occur from direct trauma, such as a fall from a height. Bruising on the bottom of the foot is highly suggestive of a Franc injury.
Pain that worsens with standing, walking or attempting to push off on the affected foot. If standard treatment for a sprain (rest, ice, elevation) does not relieve pain and swelling, you should seek care from an orthopedic surgeon.
After talking with you about your symptoms and discussing your concerns, your doctor will examine your foot and ankle. Although some physical tests the doctor will perform may be painful, none of them will make the injury worse.
The doctor may grasp your heel and twist the front of your foot to determine whether there is pain at the midfoot. In this case, the doctor is looking for a ligament injury, especially if the bones are not expected to be broken.
Because a CT scan will help evaluate the exact extent of the injury and the number of joints that have been injured, a surgeon may order this test to help plan surgery. If there are no fractures or dislocations in the joint and the ligaments are not completely torn, nonsurgical treatment may be all that is necessary for healing.
A nonsurgical treatment plan includes wearing a non-weightbearing cast or boot for 6 weeks. Your doctor will want to follow up with you regularly and take additional x -rays to make sure your foot is healing well.
The goal of surgical treatment is to realign the joints and return the broken (fractured) bone fragments to a normal position. In this procedure, the bones are positioned correctly (reduced) and held in place with plates or screws.
Because the plates or screws will be placed across joints that normally have some motion, some or all of this hardware may be removed at a later date. If the injury is severe and has damage that cannot be repaired, fusion may be recommended as the initial surgical procedure.
The basic idea is to fuse together the damaged bones so that they heal into a single, solid piece. The joints in the midfoot have very little motion and mainly transfer stress to the front of the foot.
Franc injuries that may require fusion include joints that cannot be repaired with screws or plates or when the ligaments are severely ruptured. The hardware will not need to be removed because the joints are fused and will not move after they heal.
If the patient has had internal fixation (not a fusion), impact activities, such as running and jumping, should be avoided until the hardware has been removed. Despite excellent surgical reduction and fixation, arthritis may occur from the damage to the cartilage.
(England 1995) The Franc (or Oblique) ligament secures the second metatarsal to the medial cuneiform, serving as a mortise joint anchoring the entire complex and preventing medio-lateral or plantar displacement. In elderly patients and athletes, Franc injuries may occur after low-energy rotational events.
No validated formal classification scheme exists for assessing the severity or management of a Franc injury In cases of complete ligamentous tear, ecchymosis discoloration of the plantar midfoot is common; however, findings on inspection may be subtle or absent.
The “Piano Key” test: Exacerbation of pain with dorsal and plantar flexion of each digit (Wed more 2015) Single limb heel raise: Exacerbation of pain when patient stands on one leg and then on tip toes (places significant strain on injured area) Franc Joint Normal Alignment (Case courtesy of Dr Wall Nemattalla, Radiopaedia.org.