IRRITABLE HIP

Transient synovitis (irritable hip)

• Transient synovitis is the most common cause of acute hip pain in children aged 3-8 years.

• The disease causes arthralgia and arthritis secondary to a transient inflammation of the synovium of the hip.

• Affects boys twice as often as girls.• Usually it is a diagnosis of exclusion, once

trauma and infection are excluded

Transient synovitis (irritable hip)

Symptoms

• Unilateral hip or groin pain is the most common symptom.

• Limp.• Recent history of an upper respiratory tract

infection in 50% of patients.

• Usually afebrile or have a mildly elevated temperature.

• Very young children with transient synovitis may have no symptoms other than crying at night.

Symptoms

Signs

• Hip kept in flexion with slight abduction and external rotation.

• some may have mild restriction of motion, especially to abduction and internal rotation

• The hip may be painful with passive movement and tender to palpation.

• The most sensitive test for transient synovitis is the log roll, in which the patient lies supine and the examiner gently rolls the involved limb from side to side. This may detect involuntary muscle guarding of one side when compared to the other side.

Signs

Causes

• No definitive cause of transient synovitis is known, although the following have been suggested:

– Patients with transient synovitis often have histories of trauma, which may be a cause or predisposing factor.

– One study found an increase in viral antibody titers in 67 of 80 patients with transient synovitis.

– Postvaccine or drug-mediated reactions and an allergic disposition have been cited as possible causes.

Differential diagnoses

• Perthes’ disease• Slipped epiphysis• Tuberculous synovitis• Juvenile chronic arthritis• Septic arthritis

Investigations

• Usually to rule out other diagnoses.• WBC, ESR and CRP are usually elevated in

septic arthritis.• XRAYS: can exclude bony lesions.• Ultrasound guided aspiration of the effusion.

Sign of effusion : Widening of the joint space. Note that the space is wider on the left side. Discrepancies greater than 1 mm indicate the presence of fluid.

Management

• Apply heat and massage .• Advise bedrest for 7-10 days, allowing the

patient to rest in a position of comfort.• Advise the patient with transient synovitis not

to bear weight on the affected limb.

• Advise the patient with transient synovitis to avoid full unrestricted activity until the limp and pain have resolved.

• Non-steroidal anti-inflammatory drugs (NSAIDs).

Management

Prognosis

• Usually marked improvement within 24-48 hours.

• Two thirds to three fourths of patients have complete resolution within 2 weeks.

• The remainder may have less severe symptoms for several weeks.

• The recurrence rate is 4-17%; most recurrences develop within 6 months.

Prognosis

Legg-Calvé-Perthes disease -coxa plana

Legg-Calvé-Perthes disease

• Legg-Calvé-Perthes disease (LCPD) is the name given to idiopathic osteonecrosis of the capital femoral epiphysis in a child.

• Usually ages 4-10yo• As early as 2yo, as late as teens• Boys:Girls= 4-5:1• Bilateral 10-12%• No evidence of inheritance

Legg-Calvé-Perthes disease

Pathogenesis

• Up to 4 yearsMetaphyseal vessels,lateral epiphyseal

vessels,scanty vessels from ligamentum teres

• 7 years oldVessels of ligamentum teres has developed

Between 4-7 years,femoral head depends entirely on the lateral

epiphysael vessels.

• Lateral epiphyseal vessels situated in the retinacula makes them susceptible to streching and pressure from an effusion.The precipitating cause is an effusion into the hip joint following:

Pathogenesis

• Idiopathic• Slipped capital femoral epiphysis• Trauma• Steroid use• Sickle-cell crisis• Synovitis• Congenital dislocation of the hip.

Pathogenesis

Stage 1:BONE DEATHEpisodes of ischemia leads to part of bony femoral head dies, x-ray looks normal but it

stops enlarging.

Pathogenesis

Stage 2:REVASCULARIZATION AND REPAIRNew blood vessels enter the necrotic area and

new bone is laid down on the dead trabeculae, x-ray-increased in density.If only

part of the epiphysis is involved & the repair is rapid bony architecture is completely

restored.

Pathogenesis

Stage 3:DISTORTION AND REMODELLINGIf large part of the bony epiphysis is damaged &

the repair process is slow, epiphysis may collapse and growth of the head and neck will

be distortedEpiphysis ends up flattened(coxa plana),flat and

enlarged(coxa magna) and the femoral head will be incompletely covered by the

acetabulum.

Pathogenesis

Clinical Features

• Male• 4-8 years old• Hip pain, may be referred to the medial aspect

of the ipsilateral knee or to the lateral thigh.

• All ROM are limited• The quadriceps muscles and thigh soft tissues

may undergo atrophy• The hip may develop adduction flexion

contracture

Clinical Features

• The patient may have an antalgic gait with limited hip motion.

• Passive range of motion are limited, especially internal rotation and abduction.

• Children can have a trendelenburg gait resulting from pain in the gluteus medius muscle.

Clinical Features

Investigation

• Plain radiograph– Hip radiographs, anteroposterior and frog-leg

lateral views of the pelvis to establish the diagnosis.

– Initial radiographs can be normal,

• Plain radiograph– Early changes-increased density of the bony

epiphysis and widening of the joint space.– Late changes-flattening,fragmentation and lateral

displacement of the epiphysis with rarefraction at the metaphysis.

Investigation

Catterall classification• Group I

– Epiphysis retains its height.– Less then half the nucleus is sclerotic

• Group II– Some collapse of central portion– Upto half the nucleus is sclerotic

• Group III– Most of the nucleus is involved with sclerosis, fragmentation and

collapse of head• Group IV

– Whole head is involved.– Nucleus is flat, dense and metaphyseal resorption is marked

Head at risk signs

• Progressive uncovering of the epiphysis• Calcification in the cartilage lateral to the

ossific nucleus• Radiolucent area at the lateral edge of the

bony epiphysis (Gage’s sign)• Severe metaphyseal resorption.

Herring classification

The herring classification addresses the integrity of the lateral pillar of the femoral head.

• A: there is no loss of height in the lateral one third of the head and there is little density change.

• B: there is a lucency and less than 50% loss of lateral height.

• C: there is a more than 50% loss of lateral height.

• CT scan: allow early diagnosis of bone collapse and also demonstrate subtle changes in the bone trabecular pattern.

• Ultrasonography :preliminary diagnosis of transient synovitis of the hip and the onset of CP.Hip effusion with capsular distension is well depicted on sonographic images.

• MRI: allows more precise localization of the femoral head.

Investigation

Treatment

• Skin traction as long as the hip is painful(usually takes 3 weeks)

• Further treatment is taken by assessment of the prognostic value:

• Good prognosis• 1)Onset under age 6• 2)Partial involvement of

femoral head• 3)Absence of

metaphyseal involvement• 4)Normal femoral head

shape

• No active Tx needed

Good prognosis• Onset under age 6• Partial involvement of

femoral head• Absence of metaphyseal

involvement• Normal femoral head

shape

No active Tx needed

Poor prognosis• Age over 6 years old• Involve the whole

femoral head• Severe metaphyseal

rarefraction• Lateral displacement of

femoral head

Containment

• Containment means keeping the femoral head well seated within the acetabulum

• Can be achieved by:1) Holding the hips widely abducted in plaster

or removable splint.(at least will take a year).2) Varus osteotomy of the femur or innominate

osteotomy of the pelvis.

Treatment

Guidelines to treatment

• Under 6 years:– Symptomatic

• 6 – 8 years:– Bone age at or below 6 years • Lateral pillar group A,B = symptomatic• Lateral pillar group C = Abduction brace.

– Bone age over 6 years• Group A B = abduction brace / osteotomy• Group c = outcome not affected by treatment

Guidelines to treatment

• 9 years and older:– Operative containment

Guidelines to treatment