Although most conditions that cause hip pain are benign and self-limiting, evaluation for pathology and rapid treatment is often very important and needed to prevent significant morbidity and mortality.

Patients presenting with a limp and impaired internal rotation of the hip may have a slipped capital femoral epiphysis. In this condition, the femoral epiphysis is shifted in a posterior position. Importantly, hip pain may be referred to the knee. The mean age of presentation is 12 years old, and risk factors include obesity, hypothyroidism, and growth hormone deficiency. Once the diagnosis is confirmed with plain radiographs, the patient should be placed on crutches, in non–weight-bearing status and referred to orthopedics for possible operative management.

Idiopathic necrosis of the capital femoral epiphysis of the femoral head is known as Legg-Calvé-Perthes disease (LCPD). Peak ages of presentation are between 5 and 7 years of age, and it is more common in boys than girls. Patients may initially present with a limp, as the necrosis progresses they develop hip, thigh, or knee pain. On exam, they have pain during internal rotation and abduction, and typically, plain x-rays (including frog leg views) are sufficient for diagnosis. Therapy for LCPD remains controversial. Indeed, 70% to 90% of patients have good range of motion and are without pain at 20-year follow-up regardless of initial treatment. Thus, if LCPD is suspected, the patient should be placed on non–weight-bearing status and referred to orthopedics for further evaluation and management.

Transient synovitis is a self-limiting inflammation of the synovial lining in hip joint. It occurs in boys twice as often as in girls and is most commonly found in children between 3 and 8 years old. The patient is usually afebrile and presents with a limp and unilateral hip pain. However, a small percentage of children with transient synovitis present with bilateral pain. One study found that 25% of children with transient synovitis had a joint effusion or synovial swelling on the contralateral side. The pain usually lasts for 3 to 10 days and is treated with anti-inflammatory medications and rest.