MRI of isolated cuboid stress fractures in adults.

OBJECTIVE: Isolated cuboid stress fractures are rare. The purpose of this study was to evaluate the MRI appearance of this condition.

MATERIALS AND METHODS: A retrospective search for patients with the diagnosis of a cuboid stress fracture was performed for a 19-year period. All patients underwent an initial three-view radiographic foot series for pain. MRI was performed because symptoms persisted beyond 4 weeks.

RESULTS: Ten patients, nine of whom were women, were diagnosed with isolated cuboid stress fractures. These patients were divided into an athletic group (mean age, 36.3 years) and nonathletic group (mean age, 55.0 years). In the athletic group, there were five runners, one ballet dancer, and one gymnast, and in the nonathletic group, there was one with osteoporosis, one with a plantar fascia rupture, and one who recently underwent a fasciotomy. Eight stress fractures were linear and two were stellate and all were surrounded by marrow edema. Six fractures were located inferolaterally, one superolaterally, one laterally, one medially, and one was subchondral in location. All but one involved the peroneal sulcus and cuboid crest region. Nine of 10 feet showed pathology in the plantar fascia, seven in the peroneal tendons, and four in the posterior tibial tendon.

CONCLUSION: An isolated stress fracture of the cuboid is most likely to occur in the lateral aspect of the cuboid. The cause is likely multifactorial and may include compressive and tensile forces, but plantar fascia dysfunction and age-related bone loss, which are more prevalent in women, may be additional contributing factors.