As per a recent study conducted by the investigators of Sidney Kimmel Medical College, bone marrow oedema (BME) at an os styloideum or the carpal boss is a consistent MRI finding among individuals with the dorsal wrist. The MRI is proven to be an ideal approach to validate BME. The primary aim of this study was to assess patterns of MRI findings linking carpal boss and extensor carpi radialis brevis (ECRB) tendon insertion within people with post-traumatic or overuse-related wrist pain.

A total of 84 MRI cases with carpal bossing from December 2006 to June 2015 were selected and reviewed for MRI findings associated with the type of carpal bossing, BME, insertion site, tenosynovitis/tendinosis of ECRB tendon, and insertion of ECRB tendon. Sixty-eight participants displayed clinical data on wrist pain.

The 21 per cent of participants found with fused carpal bossing, 35% with the partial coalition, and 44% with os styloideum. Sixty-four per cent of patients exhibited regional BME, 50% of unstable and 78% of stable bosses showed BME. In 20% of the cases ECRB tendon inserted on carpal boss, in 35% it was inserted on the 3rd metacarpal and in 45% on both the sites. BME was found at the corresponding insertion sites in 35%, 66% and 71% patients. Dorsal wrist pain correlated with BME as indicated by the presence of BME in carpal boss 75% of the participants. MRI findings suggested the presence of bone marrow oedema.