Makindo Medical Notes

Always consider if there is any Non accidental injury and safeguarding issues

About

• A not uncommon presentation in children

Aetiology

Causes

• Septic arthritis: Untreated intra-articular infection can lead to a permanent loss of hip function making it extremely important to differentiate possible infection from benign cases of transient synovitis
• Perthes disease, an idiopathic avascular necrosis/osteonecrosis of the femoral epiphysis, usually affects 4 to 10 year olds, peaking between 5 and 7 years. It affects about four boys x 4 and is bilateral in 10%.
• Slipped Upper Femoral Epiphyses (SUFE), displacement of the proximal femoral epiphysis off the femoral neck, usually affects 11 to 14 year olds, is more common in obese children and boys and is bilateral in 20–40%.
• Transient synovitis and septic arthritis: A young child with an irritable hip poses a diagnostic challenge. Transient synovitis and septic arthritis have similar early symptoms with the spontaneous onset of progressive hip, groin, or thigh pain; limp or inability to bear weight; fever; and irritability
• Osteomyelitis: Proximal femur or pelvic osteomyelitis presents similar to septic arthritis of the hip with fever and pain but children may have some passive range of motion if there is no extension of the infection into the joint.
• Juvenile idiopathic arthritis (JIA)Hip disease develops in 30-50% of children with JIA and is usually bilateral

Clinical

• Hip pathology may cause groin pain, referred thigh or knee pain
• Refusal to use legs and limping gait
• Refusal to weight bear
• Inability to walk, red and swollen joint
• Change in gait pattern

Movement

• Movement Active movements. Hip flexion (most children can bring their knee to touch their chest; 120(135°), hip extension(30°), abduction (45-50°), adduction (20-30°).
• Passive movements. Rotation measured with hip and knee flexed to 90°. Total internal and external rotation should equal 90°, internal rotation is greater with femoral anteversion and external rotation is greater with femoral retroversion. Femoral anteversion decreases with age (30°)

Red flags

• Pain in joint in an infant under 3 years old
• Fever, Night sweats, Weight loss and anorexia
• Night time joint pain, fatigue, Stiffness, swelling, red joint

Investigations

• FBC, U&E, CRP, Ca, Mg
• Raised CRP/EST - septic arthritis or juvenile idiopathic arthritis
• Blood cultures if infection possible
• X-ray as needed: may need to exclude fracture. Anterior posterior (AP) plain films of both hips, preferably taken with the patient standing and "frog leg" view are standard
• Ultrasound
• MRI for osteomyelitis
• Technetium bone scan identifies areas of increased osteoblastic activity and can help localize infection and subtle areas of bone injury such as early stress fracture.

Management

• Urgent referral: those children under 3 years and those over 9 years

References

• Review for the generalist: Evaluation of paediatric hip pain