Myosite ossifiante circonscrite de l’avant-bras

[Circumscribed myositis ossificans of the elbow: about a case]

Circumscribed myositis ossificans (CMO) is a heterotopic ossification of the striated muscles. Its location at the level of the elbow is rare. It occurs in young patients, often following trauma as it can also develop without experiencing any traumatic event. Its predominant location is at the level of the larger muscles limbs root (gluteus, deltoid) or of the areas which are most exposed to direct shocks (the quadriceps in more than 40% of post-traumatic cases). Our study aims to highlight the aspects of a circumscribed myositis ossificans in conventional radiology and tomodensitometry to avoid potential diagnostic confusion with a malignant bone tumor.

Post traumatic myositis ossificans: Sonographic findings

PURPOSE

The aim of this paper is to describe the sonographic (US) features of post traumatic myositis ossificans (PTMO).

METHODS

Fifteen patients with histopathological diagnosis of PTMO were included. The following US parameters were evaluated: presence of a mass, calcifications, power Doppler signals, and relationship with adjacent structures.

RESULTS

Five patients (33.3%) were diagnosed as early PTMO and 10 (66.6%) as mature PTMO. In both early and mature PTMO, US showed an oval hypoechoic mass, without infiltrative borders, located in a muscular belly. In the early phase, a center of less echogenicity was observed, associated with an outer sheet-like hyperechoic peripheral rim, while, in the mature phase, peripheral calcification created more reflections and distal acoustic shadowing was observed.

CONCLUSIONS

US is highly sensitive in the detection of PTMO, helps differentiate between PTMO and malignant soft tissue tumors, and can be used for follow-up of the lesions.