James Choi

Validation of MRI Classification System for Tibial Stress Injuries

OBJECTIVE The purpose of our study was to compare an MRI classification system for tibial stress injuries with semiquantitative MR features of injury severity and clinical outcome. MATERIALS AND METHODS Two musculoskeletal radiologists retrospectively reviewed in consensus the MR findings of 142 tibial stress injuries to quantify the degree of periosteal and bone marrow edema and grade the injuries using the Fredericson classification system (grade 1 = periosteal edema only, grade 2 = bone marrow edema visible on T2-weighted images, grade 3 = bone marrow edema visible on T1-weighted and T2-weighted images, grade 4a = multiple focal areas of intracortical signal abnormality, and grade 4b = linear areas of intracortical signal abnormality). Kruskal-Wallis tests were used to determine the relationship between the grade of stress injury and the degree of periosteal and bone marrow edema and the time to return to sports activity. RESULTS Grade 4b injuries had significantly (p < 0.002) more severe and grade 1 injuries less severe periosteal and bone marrow edema than grades 2, 3, and 4a injuries. Grade 4b injuries had significantly (p < 0.002) longer time and grade 1 injuries shorter time to return to sports activity than grades 2, 3, and 4a injuries. There was no significant difference (p = 0.06-0.79) among grades 2, 3, and 4a injuries in the degree of periosteal and bone marrow edema and the time to return to sports activity. CONCLUSION Grades 2, 3, and 4a stress injuries had similar degrees of periosteal and bone marrow edema and similar time to return to sports activity, which suggests that these three grades can be combined into a single category in an abbreviated Fredericson classification system.

Intensity of signal contacting meniscal surface in recurrent tears on MR arthrography compared with that of contrast material.

OBJECTIVE Several previous studies reported that the signal contacting the meniscal surface in a recurrent tear on MR arthrography had intensity equal to that of intraarticular contrast material. Because we failed to diagnose recurrent tears using this criterion, we reviewed our knee MR arthrograms in patients who had prior meniscal surgery. CONCLUSION On knee MR arthrograms, the signal contacting the surface of a recurrent meniscal tear may be equal to or less than that of adjacent intraarticular gadolinium contrast material.

Posterior Subtalar Facet Coalition with Calcaneal Stress Fracture

2Present address: Hawkes Bay Hospital New Zealand, Private Bag 9014, Hastings, New Zealand. Address correspondence to D. C. Moe. arsal coalition is an abnormal union (fibrous, cartilaginous, or osseous) between two tarsal bones, with a reported incidence of 1–2%. Most (90%) occur at the calcaneonavicular and talocalcaneal joints [1]. Talocalcaneal coalition usually involves the middle subtalar facet. It rarely occurs at the anterior or posterior facet [2]. Diagnosis of talocalcaneal coalition can be made by radiographs, CT, or MRI. CT classically is held as the gold standard for imaging this entity [3]. However, MRI has been reported to be equally efficacious and often is the choice when other diagnoses are considerations [3]. In this article, we present a novel case of MRI-proven partial posterior subtalar facet coalition with associated medial and lateral calcaneal stress fractures. To our knowledge, this has never been reported. Case Report A 48-year-old woman presented to the Sports Medicine Clinic with 3 months of worsening left heel pain, without preceding accident or injury. Initially she had tenderness at the origin of the plantar fascia. Stretching and arch supports were prescribed for the treatment of presumed plantar fasciitis. However, over several months she continued to suffer from chronic medial calcaneal pain, at times severe. Initial hindfoot radiographs, consisting of lateral and Harris (axial) views, were interpreted as normal. In retrospect, the lateral radiograph of the foot shows a subtle osseous protuberance at the superior margin of the calcaneal tuberosity, creating an abnormal “humpback” appearance (Fig. 1A), which is readily apparent when compared with a lateral radiograph of a normal foot (Fig. 1B). The Harris view of the T

Magnetic resonance imaging findings in patients with fibular stress injuries

ObjectiveThe objective was to evaluate magnetic resonance imaging (MRI) findings in patients with fibular stress injuries.Materials and MethodsThe study group consisted of 20 patients with clinically diagnosed fibular stress injuries who were evaluated with MRI. Radiographs were performed in 14 of the 20 patients. The MRI examinations and radiographs were retrospectively reviewed in consensus by two musculoskeletal radiologists.ResultsAll 20 patients with clinically diagnosed fibular stress injuries had periosteal edema and bone marrow edema within the fibula on MRI. The periosteal reaction and bone marrow edema were present within the distal fibula in 14 patients, the middle fibula in 1 patient, and the proximal fibula in 5 patients. The periosteal reaction was located on the anterior cortex in 1 patient, the posterior cortex in 4 patients, the lateral cortex in 11 patients, and circumferentially distributed throughout the cortex in 4 patients. Nine patients had abnormal T1 and T2 signal intensity within the fibular cortex. Initial and follow-up radiographs showed periosteal reaction in 15% and 50% of patients with fibular stress injuries respectively.ConclusionsThe majority of fibular stress injuries involve the lateral cortex of the distal fibula.

Case of the season

A 20-YEAR-OLD healthy woman presented with a 6-week history of gradually enlarging left posterior shoulder mass. She denied pain or functional problems associated with the mass. She denied history of trauma or of any other lesions. On physical examination, there was a large, nontender, mobile soft-tissue mass measuring 5 × 2 cm in size lateral to the upper thoracic spine and just medial to the superior scapula. The overlying skin was normal without erythema or warmth. No lymphadenopathy was appreciated. The neurovascular examination in the left upper extremity was normal. Shoulder had full range of motion. Ultrasound examination is shown in Figure 1, and magnetic resonance imaging (MR1) is shown in Figure 2.

A 36-year-old Woman With Posterior Shoulder Pain

A 36-year-old woman presented with posterior right shoulder pain. She was referred after imaging studies revealed a proximal humerus lesion. She reported slowly progressive pain in the right shoulder for the past 15 years. The pain was aggravated by activity. Her work as a manual laborer in a factory increased her pain. She denied any constitutional symptoms such as fevers, chills, or weight loss. Physical examination of the right shoulder revealed no skin abnormalities and no palpable masses or lymphadenopathy. There was some mild posterior shoulder tenderness. She maintained full, nonirritable range of motion in the shoulder. She had full strength throughout the right upper extremity with the exception of 4/5 strength in shoulder external rotation. There were no sensory deficits in the right upper extremity. Imaging studies included plain radiographs (Fig. 1), computed tomography (CT) imaging (Fig. 2), and magnetic resonance imaging (MRI) (Fig. 3). Based on the history, physical examination, and imaging studies, what is the differential diagnosis?