Limping is a common complaint among children presenting in the Pediatric ED the evaluation of a limp among infants and toddlers is challenging doe to the lack of specific history and the difficulty in locating the pain - therefore hip sonography is frequently used in the clinical evaluation of these children.

Sonographic examination for the diagnosis of hip effusion is routinely performed by the radiologist, however, since the integration of Point of care Ultrasound (POCUS) as part of the clinical evaluation of children in the ED in many application - Hip pocus is frequently performed by pediatric Emergency Medicine physicians.

The existing data on hip POCUS is scarce and comprised of small uncontrolled studies.

We aimed to examine the specificity and sensitivity of hip Pocus performed by pediatric emergency physicians by comparing it to the scan performed by the radiologist.

the primary outcome measurement is the ability of the POCUS exam to identify or rule out the existence of hip effusion as demonstrated in the formal radiological Ultrasound scan.

Children (0-18 years) presenting to the PED in Meir medical center with limp pain (not due to trauma) or a limp are recruited After consenting to participate in the study and completing the registration process the primary physician who is an approved researcher by the institutes IRB will perform hip POCUS as part of the clinical evaluation and will record his interpretation in the medical file. A formal ultrasound scan will be perfumed additionally by the radiologist. Both examination will be reviewed by POCUS lead physician and the Pediatric radiologist.

The patient's clinical and epidemiological data will be extracted from the electronic chart.

Inclusion Criteria: pediatric patients presenting to the PED with the complaint of a limp or a lower limb pain

-

Exclusion Criteria:

• trauma patients
• patients with an obvious diagnosis other than pain resulting from the hip joint on their physical examination.

• pediatric patients (age 0-18 years) presenting to the PED with the complaint of a limp or a lower limb pain