Metatarsal Bone Marrow Edema on Magnetic Resonance Imaging and Its Correlation to Bone Stress Injuries in Male Collegiate Basketball Players

Abstract

Background: The presence of bone marrow edema (BME) on magnetic resonance imaging (MRI) has been used to evaluate for bone stress injuries in athletes. Purpose: To examine the prevalence of MRI findings, including BME, in a single male collegiate basketball team before and after a single season and to assess its association with clinically symptomatic metatarsal bone stress injuries. Study Design: Cohort Study; Level of evidence, 3. Methods: A total of 16 men on a single collegiate basketball team (mean age, 20.0 ± 1.8 years) underwent 1.5-T MRI focused on both midfeet during the preseason, and 13 underwent repeat MRI during the postseason. MRI findings included the presence of BME and the radiographic classification of the bone stress injury (grades 1-4). Injury surveillance performed by athletic trainers was used to identify metatarsal bone stress injuries over the course of the season. Results: Preseason MRI demonstrated metatarsal BME in 5 of the 16 participants, and postseason MRI demonstrated metatarsal BME in 4 of the 13 participants. All 4 of the participants with postseason BME had MRI findings of BME in the same metatarsals. Compared to those without BME, participants with metatarsal BME had a shorter history of basketball exposure (preseason: 10.4 ± 4.1 vs 14.2 ± 1.9 years, respectively [ P = .023]; postseason: 9.6 ± 4.1 vs 14.0 ± 2.1 years, respectively [ P = .024]), and those with postseason BME had started playing at an older age (9.8 ± 4.3 vs 6.2 ± 1.6 years, respectively; P = .050). The preseason MRI classification for metatarsals included grade 1 (n = 3), followed by grades 2 and 3 (n = 2 each). In the 4 participants with postseason MRI findings, the grade increased from 1 to 4 in 1 participant and was stable in the other 3. No participants were diagnosed clinically with a metatarsal bone stress injury during the season. BME of the sesamoids was identified in 6 participants, who trended toward being older (21.0 ± 2.2 vs 19.4 ± 1.3 years, respectively; P < .10), with the abnormalities persisting on postseason MRI in all players. Conclusion: Collegiate male basketball players may have a high prevalence of BME, often without associated symptoms. The absence of foot pain or a corresponding diagnosis of a metatarsal bone stress injury in this study suggests that MRI findings of BME in asymptomatic athletes should be interpreted with caution.

Asymptomatic Bone Marrow Edema in Weight-bearing Bones in Athletes and Military Trainees: A Systematic Literature Review

“…All of the included studies reported evidence of pelvic or lower extremity aBME in their cohorts at the time of first MRI analysis. Tenforde et al found evidence of BME in seven metatarsals from five of the 16 athletes at the beginning of the athletic season, with three metatarsals having Grade 1 lesions (mild marrow edema exclusively on STIR images), two metatarsals having Grade 2 lesions (moderate marrow edema exclusively on STIR images), and two metatarsals having Grade 3 lesions (severe marrow edema or severe periosteal edema on both T1-weighted images and STIR without a fracture line); the first four metatarsals were affected, with BME seen mostly in the first and third metatarsals 6 . Kornaat et al reported that 88% of athletes in their cohort had evidence of BME before the start of the season, with 69% of these lesions localized to the ankle joint and foot 15 .…”

“…Eight of 26 recruits (30.8 %) who had positive results at time 0 showed full resolution after 4 months of training, while four recruits (15.4 %) experienced worsening of their BME [19]. Tenforde et al showed that of the 13 participants who completed the season, six (46 %) had aBME that included two new cases since the initial pre-season imaging [6]. Notably, of the four subjects with previously identified aBME, the grade improved in one, worsened in one, and was stable in the remaining two [6].…”

“…Tenforde et al showed that of the 13 participants who completed the season, six (46 %) had aBME that included two new cases since the initial pre-season imaging [6]. Notably, of the four subjects with previously identified aBME, the grade improved in one, worsened in one, and was stable in the remaining two [6]. Kornaat et al found that during the course of the season, 26 out of the 45 (58 %) assessed lesions had fluctuations in the T2weighted signal intensity, with old lesions disappearing in 10 cases (22 %) [15].…”

“…BME that is associated with pain and disability may represent a bone stress injury driven by a biomechanical overload of joints, bone turnover, and trabecular fracture [5,6]. Thus, BME is often detected in patients who are physically active such as athletes and military recruits due to the required and consistent axial loading on the lower extremities [6,7]. BME from stress injury on MRI is generally described as a low-signal on T1-weighted MRI and a highsignal on fat-suppressed T2-weighted or short tau inversion recov-ery sequences.…”

“…Current classification systems for grading bone stress injuries such as the system described by Fredericson et al [8] have been expanded to assist with further characterizing the presence of BME on fluid-sensitive MRI to identify the location of bone stress injuries. [6,9]. These may become true stress fractures when identified on MRI as having linear high-signal on fluid-sensitive sequences or linear low-signal on T1.…”