Legg-Calve´-Perthes’ disease Prof. J. Sahoo

Deffination Perthes’ disease is shelf limited condition of capital femoral epiphysis due to lack of adequate blood supply with sharp limitation of age as well as sex. Incidence: Age 5-10 (3-12) Sex M:f (4:1) Bilateral rare about 10%.

Synonyms: Coxaplana Osteochondritis deformans coxajuvenitis Pseudocoxalgia

This condition was found out by three important Orthopedics surgeons synchronously Arthur Legg Jacques Calve’ George Perthes

BLOOD SUPPLY TO FEMORAL HEAD Anatomy Medial and lateral femoral circumflex arteries. Lateral ascending cervical artery- After penetrating the lateral capsul in posterior trochanteric fossa. Intracapsular ring has been found to be incomplete more often in boys than girls. Minimal blood is supplied through the ligamentum teres. (5-7 years) the supply from the lateral epiphysial artery is receding and from midial side arterial supply is yet to be developed.

Legg-Calve´-Perthes disease Aseptic, idiopathic osteonecrosis of the femoral epiphysis Growth of the ossific nucleus stops and the bone becomes dense It is subsequently resorbed and replaced by new bone

Legg-Calve´-Perthes’ disease Etiology Trauma Hereditary factors Coagulopathy Idiopathic Altered arterial status of femoral head Abnormal venous drainage Abnormal growth and development As a sequelae to synovitis.

Level of affection according to possible pre disposing factors.

Pathogenesis Articular cartilage becomes thick getting nutrition from synovial fluid where as deeper zone of epiphysis is under nurished thus it become thin, wide and cyst formation in metaphsis (Ischaemia). Impaired and uneven revascularation following repeated infarction being aggravated by mechanical forces following subluxed head- deformed head (Resorption, repair and remodel).

Thus Waldenstorm staged the pathological process into 4 stages: Initial or Ischemic stage Resorption or fragmentation stage Reparative stage Remodelling stage

Legg-Calve´-Perthes disease Pathologic Anatomy Stage of increased density Fragmentation phase Healing phase

Legg-Calve´-Perthes disease Stage of increased density Areas of necrotic bone Subchondral fracture -Collapsed trabeculae Thickened articular cartilage

Legg-Calve´-Perthes disease Fragmentation phase Signs of repair are found “creeping substitution” Loss of height of the femoral head Growth plate is irregular and disrupted

Legg-Calve´-Perthes disease Healing phase Both woven and lamellar, predominates Trabeculae and marrow spaces regain a normal architecture

Legg-Calve´-Perthes disease Changes soft tissue of the hip joint Synovitis Articular cartilage hypertrophy Irreversible femoral head deformation Stresses of weight‑bearing pass across the acetabular margin Incapable of withstanding physiological stresses

Classification of Perthes disease According to stage of disease – Waldenstrom classification According to Prgnosticate outcome- Catterall classification Salter and Thompson classification Herring lateral pillar classification According to definning outcome- Stulberg classification

Waldenström Classification Stage-I: Stage of increased density Stage-II: Fragmentation stage Stage-III: Healing or reossification stage Stage-IV: Healed or remodeling stage Catterall classification Group-I Group-II Group-III Group-IV

Group-I Group-II Group-III Group-IV Affection of only a small part of the anterior epiphysis Group-II More of the anterior segment is involved Central sequestrum is present Epiphyseal height is preserved. Group-III Most of the epiphysis is “sequestrated” Unaffected portions located medial and lateral to the central segment Group-IV The whole epiphysis is sequestrated

Herring Lateral Pillar Classification A- Minimal density change, no loss of height B- Some density change, Height ≥50%, Central pillar collapse C- Height < 50% The Stulberg Classification System Group-I: Femoral head normal Group-II: Femoral head round, within 2 mm of circle, same circle both views Group-III: Femoral head ovoid, acetabulum matches head

Group-IV: Femoral head flattened more than 1 cm on weight-bearing areas, acetabulum also flattened Group-V: Femoral head collapsed, acetabulum not flattened

Clinical Features Painless limp leads to painful limp Pain in the groin very often refer to knee Antalgic & trendelenburg gait Decrease range of motion especially abd, internal rotation, to some extent flexion Atrophy of thigh muscle Short limb

Investigation required X-ray-AP & frog lateral view Crescent sign Salters sign Caffey’s sign USG Arthrography Bone scan MRI

Co-relation between clinico, radio & pathological state First stage Clin.- Pain, complain around knee or almost normal. Rad.- Dense head Path.- Interrupted blood vessels, more venous obstruction with few bone cell deat Second stage: Clin.- Restriction of abd, internal rotation at times flexion. (abd in flex.) Mild atrophy Rad.- Increased density and flattening. Path.- collapse of trabecular bone.

Third stage: Fourth stage: Clin.- Pain and stiff hip Rad.- Fragmentation(ant, sup & lateral aspect of epiphysis) Path.- Osteoclast invasion. Fourth stage: Clin.- Recovery of some movements of hip with reduction of pain. Rad.- Mushroom head, coxa plana. Path.- Revascularization & recanalisation.

Changes of Neck First Stage- Normal Second Stage- Some cystic change & wide Third Stage- Looks bend. Fourth Stage- Short & Bent (Coxa vara) Changes of acetabular cavity Ist- Increased ( Thick articular cartilage) Iind & IIIrd- More increased ( Hypertrophy of ligamentum Teres).

CHANGES OF ACETABULUM In late stage ( III & IV) becomes irregular and coveted, secondary to changes of head. CHANGES OF ARTICULAR CARTILAGE OF HEAD Hypertrophy in IInd and IIIrd stage CHANGES IN SYNOVIAL MEMBRANE Hyper plasia in IInd & IIIrd stage CHANGES IN CAPSULE & MUSCLE Contracted & atrophy in IIIrd & IVth stage

Cateral “ Head at Risk” Signs Clinical: Progressive loss of hip motion more so abduction Obese child Radiological: Gage sign Calcification lateral to epiphysis Diffuse metaphyseal rarefaction Lateral extrusion of femoral head Growth disturbance of physis

DIFFERENTIAL DIAGNOSIS Transient synovitis Coxavara (ICV & ACV) Tuber culosis of hip Limp (Clinical high suspicious index) 0 to 1year CDH 1 To 5years ICV 5 to 10years LCP 10 to 15years TB

Treatment : AIM Objectives Restoration and full mobility of hip Active containment of femural head Resumption of weight bearing and full activity as soon as possible. Objectives To produce a normal femoral head and neck To produce a normal acetabulum A congruous hip which is fully mobile To prevent degenerative arthiritis of the hip later in life

Factors influencing the prognosis Younger the age of onset better is the prognosis. > 9- Poor Extent of involvement of head Male- Good prognosis Catterall “head at risk” signs Passive containment Type of treatment render

TREATMENT PROTOCOL Initial phase- Restoration of normal looking head and maintain mobility. Active phase- Active containment and maintenance of full mobility. Reconstructive phase- Correction of residual deformities

Types of treatment adopted Conservative Surgical Traction Inominate osteotomy Plaster cast Femoral varus osteotomy Orthosis Combination of both Valgus osteotomy Arthroplasty

TREATMENT ACCORDING TO AGE < 5yrs: Traction in 20 degree abduction followed by weight relieving caliper > 5yrs: Without head at risk sign conservative treatment (Plaster spica followed by caliper) > 5yrs: With head at risk- varus osteotomy ( inominate osteotomy of salter does not give gratifying result alone)

Treatment according to the stage of perthes’ disease Initial phase - Physiotherapy - Active and passive ROM exercises to restore motion Traction - B/L skin traction and gradually abducting over 1-2 weeks till full abduction is regained Weight relieving caliper Active phase Aim is to have containment Conservative Ambulatory - wt relieving caliper (Toronto orthosis, Newington orthosis. Birmingham brace etc) Non-ambulatory - Abduction Broomstick, plaster cast ,Hip spica cast Surgical – different osteotomies

Utility of brace Keep head in acetabulum Pressure of acetabular rim on head is avoided Head is equally pressurized Maintain good range of movement Perpetuate formation of spherical head

Indication of different osteotomy procedures Passive abduction leading to full containment – subtrochanteric adduction osteotomy With hinged acetabulum, (Deformed head is obstructed to enter into acetabular cavity – valgus osteotomy) Inominate osteotomy is indicated with flat head (usually is combined with axer) Chilectomy is indicated to relive the prominent lateral part to achieve containment

Total hip joint replacement is the gold standard for neglected perthes’ disease with degenerative changes found in both components of hip joint in elderly patients

Critical biomechanical observation of different deformities observed with perthes’ disease Head - Flat, irregular, deformed with loss of spherocity Neck – wide, short and in varus position Trochanter – broad, prominent (beaking) Limb as a hole is short All these deformities could be explained with one preposition and i.e.,………………..

Biomechanical analysis of different changes in prox femur Add Force >>>> ABD Force Capital femoral epiphysis pushed laterally Horizontal position of metaphyseal plate Lateral subluxation of capital femoral epiphysis Irregular growth of head in relation to normal growth of trochanter-thus beaking Lilfting of abductor attachment Weakening of abductor force Vicious Cycle revolves

Thus its seems that the hole pathological deformities scenario could be changed tackling the disparity between adductor and abductor force at the outset to nip the problem in bud