Legg-Calvé-Perthes' disease

The prognostic variables include femoral head sphericity, congruence with the acetabulum, age at presentation, and the geometric extent of the femoral head involvement. Congruence is a more important predictor of future arthritis than femoral head sphericity.

The greater the age at onset, the more severe the involvement, with less re-modelling potential, a higher extent of incongruity at the end of the natural history, and a worse prognosis. However, poor outcome has been observed even in patients under 6 years of age with a large necrotic area.[77]Nakamura J, Kamegaya M, Saisu T, et al. Outcome of patients with Legg-Calvé-Perthes onset before 6 years of age. J Pediatr Orthop. 2015 Mar;35(2):144-50. http://www.ncbi.nlm.nih.gov/pubmed/24978122?tool=bestpractice.com In those with bilateral disease, sequential rather than concurrent onset of disease has been shown to be associated with poorer outcome.[78]Wiig O, Huhnstock S, Terjesen T, et al. The outcome and prognostic factors in children with bilateral Perthes' disease: a prospective study of 40 children with follow-up over five years. Bone Joint J. 2016 Apr;98-B(4):569-75. http://www.ncbi.nlm.nih.gov/pubmed/27037442?tool=bestpractice.com In later life, Legg-Calvé-Perthes' (Perthes') disease leads to a painful and poorly functioning hip. More than 50% of patients with Perthes' disease will develop signs of osteoarthritis between their 4th and 5th decades.[79]Heesakkers N, van Kempen R, Feith R, et al. The long-term prognosis of Legg-Calvé-Perthes disease: a historical prospective study with a median follow-up of forty one years. Int Orthop. 2015 May;39(5):859-63. http://www.ncbi.nlm.nih.gov/pubmed/25408489?tool=bestpractice.com Prognosis of future hip arthritis based on congruence and femoral head sphericity can be assessed using the Stulberg criteria which describe 5 different classes ranging from spherical congruency (no risk of arthritis) to aspherical incongruency (onset of severe arthritis before 50 years of age).

When girls are affected, involvement of the femoral head is more severe compared with that in boys of the same age. Females also tend to have a more severe involvement than males at a later age.

• Predictors of poor outcome include recurrent synovitis, lateral subluxation, more than 50% femoral head involvement, and a collapsed lateral pillar.

• Predictors of good outcome include femoral head involvement classified as Catterall group I or II, Salter Thompson group A, Herring sub-types A or B, and children under 7 years of age (See “Criteria” section in this topic for more information).