Legg-Calve-Perthes Disease

ByDr.AKSHAY

• FIRST DESCRIBED BY LEGG, AND WALDENSTORM IN 1909, AND BY PERTHES AND CALVE IN 1910

BLOOD SUPPLY OF HEAD OF FEMUR

DEFINITION

Legg-Calvé-Perthes disease (LCPD) is the

name given to idiopathic osteonecrosis of the

capital femoral epiphysis in a child.

Definition

• Perthes disease is a syndrome in which an avascular event affects the capital epiphysis (head) of the femur.

• Following the avascular event, growth of the ossific nucleus stopes and the bone become dens.

• Dens bone subsequently resorbed and replaced by new bone, during this the mechanical properties of the femoral head are altered such that the head tends to flatten and enlarge.

• Bilateral in 10-12 percent of the cases.

• Most prevelent in childern ages 4 to 12 years, can be seen in childern from 18 months of age to skeletal maturity.

Increased Joint space

Smaller headDenser head

Normal joint

Epidemiology

• Prevalence:

8.5%5.3% 2.8% 6.0%

77.4%

Transientsynovitis

SCFE

Infection

Perthes'disease

Other

Epidemiology

• Race: Caucasians are affected more frequently than persons of other races.

• Sex: Males are affected 4-5 times more often than females.

• Age: LCPD most commonly is seen in persons aged 3-12 years, with a median age of 7 years.

ETIOLOGY• Coagulation abnormalities involving protein C

and S (abnormal lysis of intravascular clots is likely the primary cause in some cases)

• Arterial status of the femoral head• Abnormal venous drainage of the femoral

head and neck (venous outflow obstruction)• Abnormal growth and development.• Trauma particularly in the predisposed child.• Hyperactivity or attention deficit disorder.

• Hereditary influences(genetic components)• Environmental influences , particularly

nutritional factors.• As a sequela of synovitis (synovitis may be the

first manifestation of the diseas but is rarely, if ever, the cause of the disorder)

Causes

UNIFYING HYPOTHESIS

• State that lack of thrombolysis in the venous drainage of the neck increases pressure in the femoral head circulation , resulting in AVN.

• Antecedent trauma might precipitate the avascular event.

Pathophysiology • The capital femoral epiphysis always is involved. In 15-20% of patients

with LCPD, involvement is bilateral.

• The blood supply to the capital femoral epiphysis is interrupted.

• Bone infarction occurs, especially in the subchondral cortical bone, while articular cartilage continues to grow. (Articular cartilage grows because its nutrients come from the synovial fluid.)

• Revascularization occurs, and new bone ossification starts.

Pathophysiology• At this point, a percentage of patients develop LCPD,

while other patients have normal bone growth and development.

• LCPD is present when a subchondral fracture occurs. This is usually the result of normal physical activity, not direct trauma to the area

• Changes to the epiphyseal growth plate occur secondary to the subchondral fracture.

PathogenesisAvascular necrosis

Temporary cessation of growth

Revascularization from periphery

Resumption of ossification and trauma

Pathological fracture

Resorption of underlying bone

Replacement of biologically plastic bone

Sublaxation

Deformity

CLINICAL PRESENTATION

• Onset:between age 18 months and skeletal maturity(most prevelent between 4 and 12 years of age)

• Boys 4-5 times more likely to develop the disease.

• Bilateral in 10-12% of patients.

SYMPTOMS

• Limp , first noticed by parents. • Limp is exacerbated by sternous activity and

alleviated with rest.• Pain , which may be located in the groin,

anterior hip region, or laterally around the greater trochanter.

• Often there is a reffered pai to knee.• Child may also be smaller in stature than peers.

SIGNS

• Limp is normally a combination of an antalgic and trendelenburg gait.

• Positive trendelenburg test on the involved side.• Atrophy of gluteus, quadriceps, and hamstring.• Muscle spasm.• Loss of motion is noted at maximum abduction and

internal rotation.• Log roll test will be positive.• Severe cases adduction contractures develop.

CLINICAL COURSE

• Waldenstrom defined the stages of the disease:-4 stages

1. Initial 2. Fragmentation 3. Healing (reossification) 4. Residual phase

• Clinical findings correspond to some degree with the radiographic stages of the disease.

1. Early initial stage-radiographs show only increased density of femoral head, and the patient may experience recurrent aggravation and alleviation of symptoms and signs.

2. Later initial stage-a subchondral fracture is frequently noted on radiographs (Salter’s sign)

3. Fragmentation stage- the femoral head starts to collpse and may extrude from the acetabulum. The patients limp and pain will be more pronounced , greater loss of range of motion of the affected limb.Clinical symptoms and signs progressively worsen throughout the fragmentation phase.

4. Healing stage-radiographically there is development of new bone in the subchondral regions of femoral head. Pain and limp usually started to resolve, but there is still some limitation of motion.

Initial Stage

Initial Stage

Fragmentation Stage

Fragmentation Stage

Reossification Stage

Reossification Stage

Workup

Lab Studies: • CBC• Erythrocyte sedimentation rate - May be

elevated if infection present

WorkupImaging Studies: • Plain x-rays of the hip are extremely useful in establishing the

diagnosis.• Frog leg views of the affected hip are very helpful.• Plain radiographs have a sensitivity of 97% and a specificity of 78% in

the detection of LCPD • Multiple radiographic classification systems exist, based on the extent

of abnormality of the capital femoral epiphysis.– Waldenstrom, Catterall, Salter and Thompson, and Herring are the 4

most common classification systems.– No agreement has been reached as to the best classification system.

IMAGING STUDIES

• AP-view pelvis.• Frog leg lateral.• View films sequentially over the course of

disease.• MRI• Scintigraphy• USG• CT

Radiographic Classifications

• Describe extent of epiphyseal disease• Catterall classification= most commonly used

– 4 groups based on amount of femoral head involvement

– Also presence of sequestrum, metaphyseal rxn, subchondral fx

Catterall classification

• Catterall Group I: Involvement only of the anterior epiphysis (therefore seen only on the frog lateral film)

• Catterall Group II: Central segment fragmentation and collapse. However the lateral rim is intact and thus protects the central involved area.

• Catterall Group III: The lateral head is also involved or fragmented and only the medial portion is spared. The loss of lateral support worsens the prognosis.

• Catterall Group IV: The entire head is involved. • Catterall's classification has a significant inter and intra observer error.

Catterall classification

• Groups I and II had a good prognosis (in 90%) and required no intervention.

• Groups III and IV had a poor prognosis (in 90 %) and required treatment.

• The classification is applied to the frog lateral and AP film during the fragmentation phase

Group I

Group II

Group III

Group IV

HEAD AT RISK

• Catterall also described 4 factors that he believed could be used to predict prognosis.

1. Lateral subluxation of femoral head.2. A radioluscent “V” in the lateral aspect of the

epiphysis(Gage’s sign).3. Calcification lateral to the epiphysis.4. Horizontal physeal line. The presence of these signs increased the

chances of a poor outcome.

(Herring) Lateral Pillar Classification

• Lateral Pillar Group A: There is no loss in height of the lateral 1/3 of the head and minimal density change. Fragmentation occurs in the central segment of the head.

• Lateral Pillar Group B: There is lucency and loss of height in the lateral pillar but not more that 50% of the original (contralateral) pillar height. there may be some lateral extrusion of the head.

• Lateral Pillar Group C: There is greater than 50% loss in the height of the lateral pillar. The lateral pillar is lower than the central segment early on.

Lateral Pillar Classification• 3 groups:

– A) no lateral pillar involvment

– B) >50% lat height intact

– C) <50% lat height intact

Salter-Thompson Classification

• Simplification of Catterall• Based on status of lateral margin of capital

femoral epiphysis• Group A (Catterall I & II equivalent)• Group B (Catterall III & IV equivalent)

CLASSIFICATION OF END RESULTS

• Developed to address final outcomes. Are best used to evaluate the skeletally mature patients.

1) The Mose classification:-based on fitting the contour of the healed femoral head to a template of concentric circles.

In good outcomes, the shape of femoral head deviates no more than 1mm from a given circle on both AP and frog-leg lateral radiograph.

• If the shape falls with in 2mm , it is considered a fair outcome.

• If the deviation is more than 2mm, it is a poor outcome.

1) The Stulberg classification:-reproducible system in which hips are seprated into 5 groups.

• Group-1: shape of femoral head is basically normal.• Group-2:loss of head height occurs, but head’s

contour conforms within 2mm to a concentric circle on AP & frog-leg lateral radiographs.

• Group-3:femoral head is more elliptical and deviates from a circle by more than 2mm. Contoure of acetabulum matches that of the femoral head (congruous incongruity).

• Group-4:femoral head is flattened, with the flattened area greater than 1cm in length. Contour of acetabulum matches that of the femoral head.

• Group-5:collapse of femoral head, but acetabular contour does not change (incongruous incongruity). Appearance is similar to that seen in adult avascular necrosis in which there is collapse of central portion of head.

PROGNOSTIC RISK FACTORS ASSOCIATED WITH A POOR OUTCOME

• Lateralization of the femoral head.• Extent of uncovering of femoral head.• The catterall classification. • Lateral calcification.• Lateral head displacement(using head to

teardrop distance).• Widening of the femoral head before

fragmentation.

• Saturn phenomenon (a sclerotic epiphyses surrounded by a ring of lucency).

• Widening of femoral neck in early stage of disease.

DIFFERENTIAL DIAGNOSIS

• Conditions producing AVN, as haemoglobinopathies, leukemia, lymphoma, ITP, or haemophilia.

• Hypothyroidism.• Multiple epiphyseal dysplasia• Spondyloepiphyseal dysplasia, and morquio’s

diseas if there is stronge family history of hip abnormalities.

• Traumatic dislocation of the hip resulting in AVN.• Uncommon conditions in which radiographic

findings are similar to those of perthes disease, among them Maroteaux-lamy syndrome, osteochondroma of femoral neck, multipal osteochondromatosis, synovial osteochondromatosis, schwartz-jampel syndrome, and trichorhinophalangeal syndrome.

TREATMENT

• The lateral pillar classification system coupled with the age of the patient at onset of the disease provides usefull prognostic information.

• Current treatment philosophy is to treat symptomatically those patients with group A hips and group B hips in whome onset of the disease occurred at skeletal age of 6 years or less.

• Group A hips can be spared treatment as they rarely have persistent loss of joint motion or major symptoms.

• Initial management focus on pain relief, with a reduction in activities and use of antiinflammatory medications, and short periods of bedrest for major episodes of pain or loss of joint motion.

• Group B hips in whome disease onset occurred after skeletal age 6 and all with group C hips are treated by containment once joint range of motion has been achieved by symptomatic means.

SYMPTOMATIC THERAPY

• It is by bedrest and traction.• NSAIDs for pain and discomfort and crutches

to reduce weightbearing. • The benefits of bedrest are greatest around

the time of the subchondral fracture.• In child’s home, simple longitudinal traction

using 5 pounds of weight can be attached to bed.

• It may be necessary to use the traction at night or it may be needed to be applied the entire day for several days or weeks until range of motion is regained.

• If the chiled is hospetalised, traction may also be used to gradually abduct the affected leg.

• Elevated intra-articular hip pressure secondary to synovitis has been reported to be highest when traction is applied with the hip fully extended and lowest when the hip is flexed 30-45 degree and rotated slightly externally.

• Partial weight bearing or nonweightbearing can help alleviate pain and increase range of motion. Crutches are used for this purpose.

• It can be difficult to keep a child on crutches from weightbearing-a problem that lead to development of the Snyder sling.

Non surgical containment

Non surgical containment using orthotic devices

• All braces abduct the affected hip, most allow for hip flexion and some control rotation of the limb.

• Before starting containment therapy it is important to restore range of motion to the irritable hip.

• Bedrest, traction and reduced weightbearing are helpful.

• Throughout containment treatment it is vital that range of motion be preserved, it is difficult in sever disease.

• Petrie casts:-placing patients in casts with bars between the legs so that the hips were abducted to 45 degree and rotated internally 5-10 degree.

This treatment program was achieved through traction or bedrest, with adductor tenotomy performed when required.

• Every 3-4 months the casts were changed, with the patient’s knees and ankles mobilized between changes.

• Cast containment continued untill the femoral head is well into the healing stage, average length of treatment being 19 months.

• Cast treatment particularly employed when other treatment are not effective.

• Also usefull in older patients whose range of motion is too restricted and painful to allow proper positioning of the femoral head for brace wear.

PETRIE CAST

Braces for containment

• Toronto brace:- very heavy and complicated, was created to keep the hip abducted while allowing hip and knee flexion.

• The Birmingham brace:- was created with the goal of attaining perfect immobilization.

. The brace incorporated a leather corset that extended from the nipple line to just above the knee of the affected leg.

Toronto brace

• A kneeling bar and a chain kept the foot off the ground, while a specially altered crutche permitted clearance of the abducted, internally rotated limb when the patient walked.

• Tachdjian and jouett created a fairly simple unilateral orthosis with an ischeal seat, but the device lacked enough purchase to maintain the irritable hip in proper position.

• Newington brace:- another unwieldy and complicated device, incorporates a metal A –frame with a central support for the thighs.

It also reproduces the hip position obtained with Petrie casts.

Newington brace

Atlanta Scottish Rite brace

• commonly used today.• Consists of a metal pelvic band, hip hinges, thigh cuffs,

and an extensile bar between the thigh cuffs that permits abduction of the limb but restricts adduction.

• With the hips abducted, the legs are usually flexed and externally rotated when the patient walks.

• With this brace , many patients quickly regain the ability to walk and run, and are able to return to normal physical activities.

• If range of motion of hip is lost during containment treatment, the patient was put back in traction.

• The brace was worn 24hrs a day until there was evidence of new bone formation on both AP and lateral radiographs.

• Weaned from the orthosis, with average length of treatment being 19 months.

Scotish Rite abduction brace

SURGICAL CONTAINMENT• Femoral Osteotomy:varus derotational femoral osteotomy

has been successfully used to contain the femoral head. • 2 most common indications are onset of disease after 6

years of age and a hip with poor prognosis based on radiographic findings.

• Surgery has not been found to improve outcome in children younger than 6 years at onset of disease.

• Femoral osteotomy is recommended for hips that have ‘at-risk’ radiographic signs, even if the head is not severly deformed.

• Before femoral osteotomy is performed, it is important that the patint regain a resonable range of motion.

• Femoral osteotomy should be performed before reossification of the femoral head begins.

• The extent of remodeling of the varus femoral neck depends on the growth of the capital physis, a factor difficult to predict.

• Some patients develop an abductor limp following surgery, and trochantric epiphysiodesis has been recommended when trochantric overgrowth is likely.

• A postoperative neck shaft angle of 100 to 110 degree varus has also been recommended, as femoral neck tends to grow back into valgus.

• The angle should never be less than 105 degree.

• To decrease the amount of trochantric overgrowth, some surgeons performe an epiphysiodesis of the greater trochanter at the time of osteotomy or at plate removal.

Varus Osteotomy

complications

• Excessive postoperative varus.• Failure of the varus to remodel.• Persistent external rotation of the limb.

following rotational osteotomy.• Shortening of the extremity.• Increased abductor lurch resulting in an

abductor limp.• Trochantric overgrowth.

• The need to remove the fixation device.• Fracture after removal of the plate.• Delayed union or non union.• Compared with innominate osteotomy, femoral

osteotomy has been found to cause greater shortening of the limbs and to more frequently result in abductor limp.

• Occasionally collapse of femoral head, with sever loss of range of motion.

• Loss of external rotation and abduction in some cases.• Sometimes a second osteotomy is required when first

operation does not provide adequate containment.

Innominate Osteotomy

• First performed by Salter in1962.• Preoperative prereqisites were minimam

deformity of the femoral head, non irritable hipand no significant restriction of range of motion.

• The hip had to be able to abduct to 45 degree and the femoral head had to be contained in that position.

Indications

• Onset of disease after 6 years of age.• A moderately or severely affected head.• Loss of containment.

• The capsule should not be opned.

• The iliopsoas should always be lengthened.

• If the adductor muscles are tight, they should always be lengthened.

• Postoperative casting is not necessary if the osteotomy is secured with 2 or 3 heavy threaded pins or screws.

• Kalamchi version of the Salter procedure,in this the distal pelvic fragment is repositioned into a notch created posteriorly in the proximal side of the transected ilium.

• By doing so, the acetabulum is repositioned without lengethening the pelvis, preventing increased pressure on femoral head.

Complication

• Loss of fixation with displacement of the distal fragment.

• Lengthening of the leg.• Decreased hip flexion.• Joint stiffness.• Hing abduction can also occur postoperatively.

Combined femoral and innominate osteotomy

• Indicated for severely affected hips at high risk of a poor outcom.

• Indications for the procedure are the presence of lateral subluxation, lateral calcification and considerable changes in metaphyses.

• Provide greater coverage of the femoral head than achieved with either procedure alone.

Valgus osteotomy

• Initially recommended for treating hinge abduction, in which the flattened femoral head interferes with abduction. Operation is performed if the head and acetabulum are congruent when the joint is adducted but are incongruent in a neutral or abduction position.

• Leades to improvement in gait.• Improve roundness of femoral head.

• Healed central head fragmentation.• Improved joint space, joint motion, and leg

length.• Reduced subluxation• Lessened pain.

Shelf Arthroplasty

• Indications for the operation include lateral subluxation of the femoral head, insufficient coverage of the femoral head, or hinge abduction of the hip.

• In this a deep notch is made above the acetabulum to permit the acetabular roof to be ‘pried down’.

Complications

• Loss of hip flexion due to an excessively wide augmentation graft.

• Inadequate hip coverage as the graft is too thin.

• Dysesthesia of the lateral femoral cutaneous nerve.

Chiari Osteotomy

• Pelvic osteotomy• Reserved for surgically treating the healing

femoral head that remains lateralized.• In older childern with painful hip, significant

femoral head deformity, and incongruity between the head and acetabulum.

Cheilectomy

• It surgically removing protruding fragments of femoral head(usually the anterolateral segment)

• Performed in the past.• This procedure weakens the attachment of the

femoral head to the neck, which can result in epiphyseal slippage.

• Postoperative joint stiffness.• Should always be done after closure of capital

physis to avoid a slipped epiphysis.

SUMMARY

• For patients less that 6 years old the prognosis is good for the majority.

• If they are stiff or painful they respond to bed rest, traction and pain relieving anti-inflammatory medication.

• There is no evidence that abduction splints or surgical intervention is warranted in the majority of these younger patients.

SUMMARY• For patients between 6 and 8 years but with a bone age

less than 6 and an intact lateral pillar (Herring A and B) the prognosis is similar to that for the first group and observation is as good as surgical intervention for the majority.

• If they have bone ages greater than 6 years and Herring lateral pillar classification B then "containment" of the head within the acetabulum seems to be warranted.

• This may be done by abduction bracing, femoral varus osteotomy or a pelvic osteotomy.

SUMMARY• If they are between 6 and 8 and are in lateral pillar group

C then the result of intervention are equivocal. • Children presenting with Perthes disease at age 9 or

older often have lateral pillar B or C and a poor prognosis.

• The trend is towards early containment of these hips although stiffness can be a problem following early pelvic (Salter's) osteotomy.

Prognosis

• The younger the age of onset of LCPD, the better the prognosis.

• Children older than 10 years have a very high risk of developing osteoarthritis.

• Most patients have a favorable outcome.• Prognosis is proportional to the degree of

radiologic involvement.