[Ischiopubic osteochondrosis revealed by an atypical "acute transient synovitis of the hip": A case report].

We report here the case of a 3-year-old patient, who presented a left limp and a total refusal of walking, without any traumatism. Clinical examination revealed a significant pain in the left leg with a limit to the limiting mobilization. Acute phase reactants were slightly elevated. Based on the hip ultrasound, acute transient synovitis of the hip was diagnosed. Following persistent complaints, a hip plain radiography was performed, showing a discreet reshuffle at the right ischiopubic branch. The MRI of the hip revealed a discrete T2 high intensity centered on the right ischiopubic synchondrosis (IPS), corresponding to a Van Neck-Odelberg osteochondrosis. Non-steroidal anti-inflammatory drugs and limited weight bearing enabled significant clinical improvement. The ischiopubic osteochondrosis is a physiological phenomenon, frequent and mostly asymptomatic. However, when associated with pain, it could easily be mistaken for another musculoskeletal or rheumatological disorder. Therefore, it is important to continue investigating more thoroughly any limping that does not have a typical evolution from the presumed diagnosis.