Hip Conditions

Developmental Dysplasia of the hip (DDH)

This represents a spectrum of conditions which affect the proximal femur and acetabulum, seen in new-borns

– The junction between femur and acetabulum is not properly formed which results in deformity which can range from mild dysplasia to subluxation and full dislocation of the hip

– It is much more common in females and more common in the left hip

– The biggest risk factor is breech presentation, as well as a positive family history and oligohydramnios

– Therefore, all breech babies born at 36+ weeks gestation require bilateral hip ultrasound scan at 6 weeks

Symptoms:

– Limp or abnormal gate

– Ability to sublax or fully dislocate hip

– Asymmetry of the skinfolds around the hip

– Limited hip abduction

– Shortening of the affected leg

– If left untreated can lead to early onset arthritis

Diagnosis:

There are 2 tests which are done at birth (NIPE) and which screen for DDH

–  If these are positive then do ultrasound scan of the hip (Diagnostic test) or X-ray if child older than 4.5 months

Barlow test:

– This attempts to dislocate an articulated femoral head posteriorly out of the acetabulum

Ortolani test:

– This attempt to relocate a dislocated femoral head back into the acetabulum on abduction

Management:

– If mild dysplasia –> may self-resolve

– If moderate/severe –> Pavlik harness (fixes hip in flexion and abduction)

– For older children or if conservative measures fail –> surgery

Transient Synovitis

This is a condition, known as “irritable hip” which gives transient inflammation of the synovium (inner lining) of the capsule of the hip joint.

– It is the commonest cause of hip pain in children and usually affects children younger than 10 years old.

– It often presents during or following a viral infection giving fever, but the exact cause is unknown

Symptoms:

– Acute-onset hip pain

– May have a grade fever

– Lim with or without pain

– In younger children, may have unexplained crying when changing nappy

– Decreased range of motion (especially internal rotation)

Diagnosis:

It is a diagnosis of exclusion once other more serious causes (e.g., septic arthritis) ruled out

Management:

Rest and anti-inflammatories. The condition usually self-resolves within a few days

Legg-Calve-Perthes’ Disease

This is a condition which is characterised by a disruption of blood supply to the femoral head

– It is classically seen in young boys around the ages of 4-8

– The interrupted blood supply causes avascular necrosis of the capital femoral epiphysis

– Over time, this heals by revascularisation and removal of the necrotic bone, but there is an overall loss of bone mass and a weakening of the femoral head, which can lead to complications later

Symptoms:

– Hip pain (can be bilateral) which may be referred to the knee (can originally be dismissed as growing pains)

– Joint stiffness with reduced range of movement

– Problems with weight bearing giving limping

– Can later lead to osteoarthritis and premature fusion of the growth plates blunting growth

Diagnosis:

– X-ray –> initially shows widening of joint space, increased density in the femoral head

–> in later disease shows small, flattened, fragmented or irregular femoral head

– Bone scan or MRI –> used if normal X-ray but symptoms persist

Management:

The aim is to reduce pressure on the joint till the disease can run its course

– The younger the child the more conservative measures like watching and waiting are preferred

– Options include traction, braces to restore range of motion and physiotherapy

– If irreversible joint damage has occurred –> surgery is required

Symptoms:

– Hip pain –> but can cause isolated groin/knee pain

– Loss of internal rotation of the hip in flexion

– Limp and pain on movement

– If left untreated, can lead to avascular necrosis of the femoral head

Diagnosis:

–  X-ray: AP and lateral (frog-leg) views shows displacement of epiphysis

Management:

Open reduction and fixation with a screw through the centre of the epiphysis