Transient Hip Synovitis, 146 Cases, Origin and Duration.

Transient hip synovitis is one of the most common paediatric orthopaedic diseases. This non-controlled interventional study investigated the origin, clinical findings, imaging and the duration of symptoms. 146 affected patients out of the total of 27659 patients under 18 years result in an incidence of 0.53%. 76.7% boys outweighed 23.3% girls (1.8-12.9 years [Ø 6.3 y, boys Ø 6.5 y, girls Ø 6.2 y]). Diagnoses were defined by ultrasound and the absence of concurrent diseases. In 60.5% of patients, the right hip was affected, in 39.5% the left. A single patient had CF on both sides but not at the same time. No simultaneous incidence was recorded. There were two singular recurrences. Within the study period, we counted 11 cases of Perthes' disease, 2 juvenile hip arthritis and one septic hip. Patients' history showed 41.0% viral infections, 21.6% physical exertion and 15.1% singular trauma. In 22.3% no origin could be named. Clinical aspects included pain in inward rotation (51.5%), in hip flexion (49.3%) and limping (37.5%). Ultrasound depicted medium joint effusion in 53.4%, marked effusion in 46.6% and synovial thickening in 17.1% of patients. 119 patients could be followed up weekly. Joint effusion vanished after 3-36 days (Ø 13.3 d), clinical symptoms Ø 1.6 days earlier. Total duration in terms of sonographic appearance of effusion was 3 to 37 days (Ø 19.1 d).