Hip

Key points 

• Hip problems can cause pain in the groin, thigh or knee (called referred pain).
• Hernia and testes problems can cause pain in the groin / hip area.
• Pain in the hip can be referred from the lower back (so check the spine, especially sacroiliac joints), the pelvis or abdomen. 
• Hip pathology covers red flag conditions (infections and rarely malignancy), inflammatory arthritis and other orthopaedic conditions (Slipped Upper [Capital] Femoral Epiphysis, Legg-Calve-Perthes disease and Developmental Dysplasia of the Hip). 

Slipped Upper Femoral [or Capital] Epiphysis - SUFE (or SCFE) - results in displacement of the epiphysis of the femoral head.  SUFE is most common at 10–15 years of age during the adolescent growth spurt and can associate with being overweight or hypothyroid.  The presentation can be acute, non-weight bearing or be a more gradual presentation with pain, limp and limited hip movement. SUFE usually affects one side but can involve both hips.  SUFE / SCFE can occur in children with other conditions such as Juvenile Idiopathic Arthritis (beware the child with JIA and acute limp and hip restriction).  The diagnosis can be confirmed by hip radiograph. Prompt referral to orthopaedics is needed as treatment is surgical. Delayed treatment increases the likelihood of avascular necrosis, secondary osteoarthritis and disability.

Legg-Calve-Perthes ('Perthes disease') is most often seen in young boys (age range 4-8 years) with acute limp, often non-weight bearing but can also be more gradual onset. Interruption of the blood supply causes avascular necrosis of the capital femoral epiphysis of the femoral head.  Urgent referral to orthopaedics is necessary. Treatment is rest and splinting in abduction. Delay in treatment can result in secondary osteoarthritis. 

Developmental Dysplasia of the Hip (DDH), replaces the term Congenital Dislocation of the hip and results from abnormal development of the pelvis and hip anatomy. The hip may have potential to dislocate. DDH may be detectable as part of the newborn check, as well as at the 6 week baby check. DDH can affect one or both hips. The diagnosis is confirmed by ultrasound. Babies at high risk are those with a family history of hip problems in early life, breech presentations and should be referred for ultrasound scan of the hips regardless. DDH may present in toddlers or even later in life with limp, hip pain or referred pain to the knee or thigh. Clues may be a short leg, asymmetrical skin folds, walking with the affected leg held in external rotation or tip-toe walking on the affected side. Early diagnosis and referral to orthopaedics is important.