The Irritable Hip

Musculoskeletal Education ProgramRCSI Professorial Unit Cappagh National Orthopaedic Hospital

The Irritable HipTerm used to describe a syndrome which is seen in children, particularly 4 8 age group

Main feature is the presence of a limp

Onset is insidious often no pain

Most outstanding clinical feature is loss of internal rotation in the affected hip

The Irritable HipConditions that may be responsible

Transient Synovitis of the hip

Perthes Disease

Infection

It is common practice to admit children with irritable hips for symptomatic treatment until the diagnosis has been firmly established

Transient Synovitis of the Hip

Transient Synovitis of the HipMost common cause of irritable hip syndromeChild presents with a limp

No accompanying systemic upsetESR and FBC normal

Main pathological feature is excess synovial fluid

Radiological findings are either completely normal or show a slight joint spaceEffusion may be visible on hip ultrasound

Transient Synovitis of the HipRelatively short lived acute inflammatory process

Usually seen in boys aged 2 to 10 years

Frequently follows an upper respiratory tract infection

Most common cause of painful hips in childhood

Diagnosis of exclusion

Transient Synovitis of the HipTreatmentAspiration of hip is not routinely performedIf carried out, synovial fluid will be sterile and have a clear appearance

Joint is rested by confining the child to bed

It is usual to apply a little light skin traction to the affected limb

Hip is kept under observation weight bearing permitted when movement fully recovered ( 6 weeks)

Treatment

Perthes Disease

Perthes DiseaseChild usually presents with a limp of insidious onset

No systemic upset

M > F, 5:1; age 2 6 years

Can appear as late as 9 years of age

Pathological Features of Perthes DiseaseResult of a disturbance of the blood supply to the femoral epiphysisCause is unknown ? an error in the re-organisation of blood vessels in the proximal femurBoth hips may be involvedEither simultaneously or with an intervalWhen condition is in the active phase Bone becomes quite softIf a significant proportion of the femoral epiphysis is affected, the pressure of weight bearing will lead to deformity of the femoral headAcetabulum adapts to this change and becomes misshapen

Perthes Disease

Clinical Features of Perthes DiseaseFrequently presents with a limp (may be painless)

Often, child complains of vague pain / discomfort in the region of the hips, thighs or knees

Always some internal rotation in affected hipMain cause id protective muscle spasm

Usually loss of extensionDue to excess synovial fluid

Clinical Features of Perthes DiseaseNatural tendency is toward spontaneous resolutionOccurs by revascularisation of avascular areas of bone

Slow process can take 18 monthsWhen complete, protective muscle spasm resolvesMovement in hip improves

If permanent deformity of femoral head, recovery will be incompleteAltered shape of femoral head / acetabulum predisposes to development of secondary OA

DiagnosisInitially, radiographs of hips may show signs of a joint effusion

By the time pt becomes symptomatic, specific diagnostic features are invariably presentApparent increase in the density of the epiphysis which is smaller than normal

Radiographs can also be used to Grade the severity of the caseSuggest a prognosisAct as a guide to treatment

Perthes Disease

Perthes DiseaseMRI can unequivocally identify how much of the femoral head has become avascular

Catterall Grading of Perthes DiseaseGrade 1Cyst formation in anterolateral aspect of epiphysis onlyArea involved may successfully revascularise without deformity

Grade 2More of the femoral head involvedSome bony collapse will occur

Grade 3Most of head is affected

Grade 4All of head is involvedPoor prognosis

TreatmentIn the initial stages, if discomfort and painAdmission for bed rest and skin traction If severity is established as Grade 1, once acute symptoms have settled no other tx required

Grade 2-4Bedrest and splintage (avoids weight bearing)Osteotomy of femoral neckMay help acetabulum contain femoral head during revascularisationAfter revascularisation it is usually possible to give a reasonably accurate prognosis

Splints

Acute Pyogenic Arthritis of the Hip (Septic Arthritis)

Acute Pyogenic Arthritis of the HipSerious condition which must be dealt with promptly and efficientlyUnless promptly treated the hip is rapidly and irreversibly destroyed

Cause is usually a blood borne staphylococcus

Onset is rapid and accompanied by a profound systemic disturbanceUnable to weight bearToxic high fever, rigors, sweating, deliriousGreat pain in joint muscle spasm and movementMovement of joint is feared!!!

Acute Pyogenic Arthritis of the HipKocher criteria (for child with painful hip)Includes: non-weight bearing on affect side, ESR > 40 mm/hr, fever, and a WBC count of >12,000 mm3

4/4 criteria are met, there is a 99% chance that the child has septic arthritis3/4 criteria are met, there is a 93% chance of septic arthritis2/4 criteria are met, there is a 40% chance of septic arthritis1/4 criteria are met, there is a 3% chance of septic arthritis

Acute Pyogenic Arthritis of the HipTreatmentTraction is applied to the hipBlood cultures performedHip may require aspirationReduces intra-articular pressure, relieves pain and obtain pus samples for bacteriology

Antibiotic treatment should be started immediatelyIV broad spectrum until sensitivity results known

With prompt treatment the infection can be abortedIf significant delay, much joint destruction arthrodesis may be required

Acute Pyogenic Arthritis of the Hip