Definition

1. Legg-Calve-Perthes Disease(coxa plana, osteochondrosis capitis femorisavascular necrosis of the femoral head)

2. Definition Idiopathic osteonecrosis of the capital femoral epiphysis of the femoral head of unknown aetiology. It is a self-limited disease.

3. Etiology • Infection, trauma, synovitis • Disruption of blood flow to capital femoral epiphysis (CFE)‏ • Systemic disorder (delayed skeletal maturation, abnormalities of thyroid hormone and insulin like growth factor • Hereditary influence, environmental influence, hyperactivity

4. Blood flow to CFE

5. Epidemiology • One in 1200 children younger than 15 years is affected by LCPD • Males are affected 4-5 times more often than females • LCPD most commonly is seen in persons aged 4-8 (2-12) years, with a average age of 7 years • Bilateral involvment 10 -15%

6. Pathology • The blood supply to the capital femoral epiphysis is interrupted (arteries and veins). • 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. • Changes to the epiphyseal growth plate occur secondary to the subchondral fracture.

7. Symptoms • Painless limp • Hip or groin pain, which may be referred to the thigh • Mild or intermittent pain in anterior thigh or knee • Usually no history of trauma

8. Symptoms • Decreased range of motion (ROM), particularly with internal rotation and abduction • Painful gait • Atrophy of thigh muscles secondary to disuse • Muscle spasm- mild hip contracture of 10-20 degrees may be present

9. Symptoms • Leg length inequality due to collapse • Thigh atrophy: Thigh circumference on the involved side will be smaller than on the unaffected side secondary to disuse (Trendelenburg sign)‏

10. Trendelenburg sign

11. Diagnosis • Clinical presentation, physical examination • RTG- A-P, frog-leg lateral views (every 6 weeks at the beginning, every 3-6 months later)‏ • USG- synovitis • MRI, artrography

12. Stages – radiographic presentation • Ischaemia / Necrosis • Fragmentation / Resorption • Reossification / Healing • Residual stage

13. Initial stage- necrosis • Decreased size of ossification center • Lateralization of femoral head • Subchondral fracture • Physeal irregularity

14. Fragmetation- resorption • Fragmented epiphysis • More irregular acetabular contour

15. Reossification- healing • New bone formation- the bone density returns

16. Residual stage • Reossified femoral head • Remodeling of the head shape • Remodeling of the acetabulum

17. Catterall classification Stage 1: • Antero-medial portion of head involved and no collapse, metaphyseal changes do not occur and the epiphyseal plate is not involved • Heal without significant sequelae Stage 2: • More head involved and may - fragmentation of the involved segment • The involved segment shows increased density and uninvolved pillars of normal bone prevent significant collapse - regeneration without much loss of height and the end result is usually good. Metaphyseal reaction localised

18. Catterall classification Stage 3: • More of the head involved - collapse as uninvolved pillars not large enough t prevent collapse • May show head within a head • The metaphysis is usually diffusely involved - broad neck and the epiphyseal plate is unprotected and also usually involved - results poorer Stage 4: • Whole head involvement and severe collapse occurs early and restoration of the femoral head usually less complete • The metaphyseal changes may be extensive • The epiphyseal plate is often involved - abnormal growth (coxa magna, coxa breva, coxa vara and coxa valga)

19. Herring classification • Lateral pillar clasification • Detrmine treatment and prognosis

20. Salter - Thompson Classification • Stage A: - Lateral portion of femoral capital epiphysis present - less than 50% head involved • Stage B: - Lateral portion of femoral capital epiphysis absent - more than 50% head involved (Lateral margin of epiphysis protects epiphysis from stress)‏

21. Differential diagnosis

22. Mose method • If head conforms to a single ring in both X-Ray planes - good prognosis • If head varies from perfect circle by no more than 2mm - fair results • If head varies by more than 2mm in any plane - poor results

23. Neck-shaft angle

24. Centre-edge angle (Wiberg`s angle)

25. Centre-edge angle • 5-8 years ~19 degrees • 9-12 years ~25 degrees • 13-20 years 26-30 degrees

30. Goal of treatment • Preservation of the roundness of the femoral head and prevention of deformity while the condition runs its course.

31. Conservative treatment • Relieve weight bearing • Achieve and maintain ROM • Containment of the femoral epiphysis within the confines of the acetabulum (Petrie-style casts, Atlanta /Scottish Rite/ brace, Toronto braceand other orthotic devices)‏

32. Conservative treatment

33. Conservative treatment

34. Conservative treatment

35. Surgical treatment • Femoral osteotomy = varus +/- derotation to reduce the degree of anteversion & extension. • Pelvic osteotomy (Salter, Chiari, Shelf) or Femoral osteotomy have similar results

36. Surgical treatment Shelf acebuloplasty

37. Surgical treatment • Salter osteotomy

38. Very good radiographic resultsbefrore surgery (7 years 2 months)‏

39. Very good radiographic results3 years after surgery

40. Very good radiographic results6 years after surgery

41. Poor radiographic resultbefore surgery (7 years 8 months)‏

42. Poor radiographic result6 months after surgery

43. Poor radiographic result 8 years after surgery