Overview
In Legg-Calvé-Perthes disease (LCPD) the blood supply of the capital femoral epiphysis is disrupted to a variable extent, causing epiphyseal osteonecrosis and chondronecrosis with arrest of epiphyseal growth. The necrotic bone is resorbed and replaced. During the resorptive (fragmentation) stage the head is mechanically weak, and heads with more necrosis flatten (coxa plana). The head then reossifies, regrows (often with coxa magna) and remodels until maturity. (Tachdjian)
Differential Diagnosis (Tachdjian)
Consider multiple and spondyloepiphyseal dysplasias, hypothyroidism, mucopolysaccharidoses, osteonecrosis after steroids, sickle cell disease, Gaucher disease, leukemia, traumatic dislocation or septic arthritis, and osteonecrosis after DDH treatment. Epiphyseal dysplasias are bilateral and symmetric at the same time, with short stature and other epiphyses involved, whereas bilateral LCPD is usually sequential, a year or more apart.
Classification (Tachdjian)
Lateral pillar (Herring, modified 2004)
Applied on the AP radiograph in the mid-fragmentation stage (earlier application is inaccurate).
Group | Lateral pillar |
|---|---|
A | No density change, no loss of height |
B | Lucency with height loss not exceeding 50% |
B/C border | Narrow (2 to 3 mm), poorly ossified pillar with more than 50% height, or exactly 50% |
C | More than 50% loss of height |
Group A does best, B intermediate and C worst. An intact lateral pillar shields the central necrotic segment from stress. Compared with Catterall, it has better interobserver reliability and prediction of outcome, but it cannot be used before fragmentation and is less prognostic in children over 12. Perfusion MRI is being used to judge necrosis early.
Stulberg (outcome at skeletal maturity)
I: normal hip. II: spherical head (same concentric circle on AP and frog-leg views) with coxa magna, short neck or steep acetabulum.
III: ovoid head deviating more than 2 mm from a circle. IV: flattened head (the authors use more than 1 cm of flattening in the weight-bearing area), with matching acetabular shape (aspherical congruency).
V: collapsed head with a normal acetabulum (aspherical incongruency).
At about 40 years, groups I and II have a good prognosis, while III to V show arthritis.
Principles of Containment (Tachdjian)
Most treatment is based on containment: if the head is held within the acetabulum, it should heal in the acetabular shape ("biologic plasticity"). However, the modest benefit of containment and the recognized biologic component of deformity have led to questioning of the concept. Finite-element work suggests containment osteotomy offers no mechanical protection once extensive necrosis is present.
Nonoperative Treatment (Tachdjian)
Symptomatic care: avoid running and jumping, protected weight bearing on crutches (or a wheelchair for compliance), short courses of NSAIDs (avoid long-term use, which may impair bone formation), and brief bed rest to relieve synovitis and restore motion early in the disease. Traction is used less often now.
Restore motion first. Before any containment, recover range of motion of the "irritable" hip with rest, reduced weight bearing, traction or Petrie casts, and preserve it throughout treatment.
Petrie (broomstick) casts: about 45 degrees of abduction and 5 to 10 degrees of internal rotation, often applied under anesthesia with arthrography and adductor tenotomy if needed. Results in retrospective studies are comparable to osteotomy. Short (6-week) courses without subsequent containment risk recurrent stiffness and hinge abduction. An A-frame wide abduction brace worn 8 to 12 hours a day (mainly at night) for about 12 months can maintain abduction; in one series of over 200 hips most lateral pillar B hips and many C hips reached modified Stulberg I or II.
Ambulatory braces (Atlanta Scottish Rite): early reports were favorable, but more recent studies show no therapeutic effect, and the authors now brace few children.
Femoral Varus Osteotomy (Tachdjian)
Indications
A containable hip, usually in the initial or fragmentation stage, with at least 20 degrees of abduction in extension. Regain motion beforehand (staged Petrie casts if needed), since stiffness and adduction or flexion contractures may worsen afterward.
Current trend: operate early in children older than 8 at onset, before head collapse. The authors use perfusion MRI and recommend early surgery in this group when more than 50% of the head is hypoperfused.
In a multicenter prospective study, children over 8 at onset who became lateral pillar B or B/C improved with femoral varus or Salter osteotomy compared with nonoperative care. The 6 to 8 age group had similar outcomes with or without surgery, lateral pillar C hips did poorly regardless of treatment, and children under 6 do well (about 80% Stulberg I or II) without surgery.
Technique points
Limit varus to about 15 degrees when operating early; greater varus did not improve Stulberg outcome. More varus may be needed later in the disease to contain a deformed head. Some recommend never going below a neck-shaft angle of 105 degrees.
Blade plate fixation is most common. An opening wedge reduces shortening. Extension-derotation or rotational osteotomy can reposition the head.
Consider trochanteric apophysiodesis (a bone peg is more effective than a screw) at the time of osteotomy or plate removal to prevent trochanteric overgrowth and abductor limp, especially at or before about 8.5 years.
Some authors keep the patient non-weight bearing until the lateral pillar reossifies.
Complications
Excessive or unremodeled varus, persistent external rotation after rotational osteotomy, limb shortening, trochanteric overgrowth with abductor (Trendelenburg) limp, fracture after plate removal, delayed union or nonunion, and occasional further head collapse with loss of motion. Compared with innominate osteotomy, femoral osteotomy causes more shortening and abductor limp. In a 42-year follow-up, 7 of 35 patients had total hip arthroplasty, and about two thirds of the remainder had good Harris hip scores.
Additional Detail from Campbell
Diagnosis (Campbell)
Boys are affected about three times as often as girls; average age is 7 years. Symptoms average about 6 weeks before diagnosis, and radiographic changes (condensation, sclerosis) lag about 6 weeks behind symptoms, so a child with hip pain and normal radiographs should be reimaged at 6 weeks if still symptomatic. MRI (or scintigraphy) shows the disease earlier.
Waldenström stages: initial (small sclerotic epiphysis, medial joint space widening; radiographs may stay occult 3 to 6 months), fragmentation (head appears to fragment; symptoms peak; lateral pillar classified here), reossification (up to 18 months) and healing/remodeling until maturity.
Meyer dysplasia mimics LCPD: more common in boys under 4, often bilateral, with delayed, small, cracked or cystic ossification centers but without condensation, subchondral fracture, fragmentation or subluxation.
Bilateral disease (about 10%) is usually more severe and asynchronous; distinguish from multiple epiphyseal dysplasia with radiographs of other joints and a bone age (delayed in LCPD).
Other classifications: Catterall groups I to IV with head-at-risk signs (Gage sign, lateral calcification, lateral subluxation, horizontal physis, metaphyseal cyst); Salter-Thompson type A (subchondral fracture under 50% of the dome) or B (over 50%), which is visible earlier (about 8 months). In Herring's series, group B did well under 9 years of bone age but less well over 9, and group C did poorly regardless of age or treatment. The pillar group may change from A to C during fragmentation.
Perfusion MRI can predict lateral pillar involvement in early fragmentation, but about 50% of children need sedation and it may not change treatment.
Treatment protocol (Campbell)
Explain the 24- to 36-month natural history. Children 2 to 3 years old can be observed.
From age 4: after synovitis resolves, daily home range-of-motion and stretching. Loss of motion signals a worse prognosis; treat with bed rest, skin traction, therapy, abduction exercises, pool therapy or bracing. If motion does not improve, perform examination under anesthesia with percutaneous adductor longus tenotomy and ambulatory abduction (Petrie) casts for 6 weeks or more.
If containment is at risk with lateral subluxation, operate in the early fragmentation stage, before the head deforms. Timing and indications matter more than the procedure. Older children with lateral pillar B and B/C involvement do better with surgery.
Varus derotational osteotomy versus innominate osteotomy: both have good long-term results and neither accelerates healing. Femoral varus risks persistent excessive varus if the capital physis closes and causes mild shortening; innominate osteotomy gives anterolateral coverage and mild lengthening and avoids plate removal, but may not contain the head in older children and may increase joint pressure. The choice should follow the surgeon's expertise.
Innominate osteotomy (Canale technique): Smith-Petersen approach, release of the psoas tendon, Gigli saw cut through the sciatic notch just above the acetabulum, opening by hip flexion-abduction, and a full-thickness 2 x 3 cm quadrilateral iliac graft impacted into the gap with pin fixation. Salter, Pemberton, Dega, Bernese or Ganz periacetabular osteotomies are alternatives, the latter for the residual phase.
References
Kim HKW, Herring JA. Legg-Calvé-Perthes disease. In: Herring JA, ed. Tachdjian's Pediatric Orthopaedics. Philadelphia: Elsevier. Chapter 14.
Sheffer BW. Osteochondrosis or epiphysitis and other miscellaneous affections. In: Azar FM, Sawyer JR, Throckmorton TW, eds. Campbell's Operative Orthopaedics. 15th ed. Philadelphia: Elsevier; 2026. Chapter 34, Legg-Calvé-Perthes disease.