Department of Family Medicine, Boston University School of Medicine (Dr. Roman); Department of Orthopedics, St. Elizabeth’s Medical Center and Harvard Medical School, Boston (Dr. Van Lancker) aileen.roman@bmc.org
Dr. Roman reported no potential conflict of interest relevant to this article. Dr. Van Lancker is a consultant to Conventus Orthopaedics, Globus Medical, and Stryker.
Other frequently missed types of ankle fracture are shown in FIGURE 3.22 These are relatively uncommon injuries that can be missed for a number of reasons, alone or in combination, including their subtlety on radiography, their often vague clinical presentation, and providers’ lack of awareness of these types. Identification or strong suspicion of fracture at any of these sites (ie, in a patient who is persistently unable to bear weight) should prompt orthopedic referral.
IMAGES COURTESY OF HANS P. VAN LANCKER, MD, FRCSC
Lisfranc injury
The tarsometatarsal joint comprises 3 cuneiforms, the cuboid, and 5 metatarsals. Stability is maintained by an intricate ligamentous complex. Lisfranc injury comprises a spectrum of midfoot injuries in which 1 or more metatarsals are displaced from the tarsus. These injuries are both rare and notoriously difficult to diagnose: As many as 20% of cases are missed on initial assessment. Without proper treatment, long-term disability and deformity, such as pes planus, can result.22-24 Lisfranc injuries typically result from a direct blow to the midfoot or excessive pronation or supination in a plantarflexed foot.23
Presentation. A historical clue to Lisfranc injury is a report of pain while walking down stairs. Patients can present with pain, swelling, and tenderness to palpation over the dorsal aspect of the Lisfranc joint. Weight-bearing on the injured foot frequently cannot be tolerated but is occasionally possible in some patients, especially those who have diabetes or other baseline neuropathy.23
Examination. Physical examination can also reveal plantar ecchymosis, which is considered pathognomonic. Another highly supportive maneuver is passive abduction and pronation of the forefoot, which can elicit pain.25,26
Imaging. Lisfranc injury can be diagnosed on weight-bearing x-rays; as many as one-half of cases are missed when only non-weight-bearing films are obtained. If initial weight-bearing cannot be tolerated by the patient, another attempt at imaging can be made after 1 week of rest.24