Legg Calve Perthes

As with most childhood injuries this condition was named after the 2 Doctors that first described it Legg-Calve and Perthes in the early 1900’s. The condition affects the upper part of the thigh bone where it forms the hip joint with the pelvis. Damage occurs to the blood vessels of the head of the Femur causing the shape of the head of the femur to change overtime.

The condition tends to start early in life ranging anything from 2-13. But the most common age of presentation is between 6-9 years old for girls and 7-11 years old for boys. These are the ages where primary ossification of the bone are occurring and the femoral head changing in shape and structure from softer cartilage to firmer bone and the blood supply is at an increased risk of damage.

This condition can also be referred to as: ischaemic necrosis of the hip, osteochondritis or avascular necrosis of the femoral head.

Legg-Calve Perthes (LCP) can present with a number of symptoms:

• Limp where the knee lifts up and out to walk, more noticeable late in the day or after prolonged sitting.

• Pain usually worse later in the day and after activity.

• Reduced ability to move the hip in the same way as the other hip.

There are 2 broad categories of presentation for these patients:

• Child that has had an innocuous contact to the hip (this is not often remembered).

• A very physically active child who has developed hip pain over a period of time.

• The prevalence of this injury is relatively rare. Affecting less than 4 in 100,000 children, with boys 5 times more likely than girls.

• The conditions affect all races but Caucasians more so.

• Children who have poorer nutrition are also more likely to suffer with this condition, particularly around calcium and vitamin D intake.

There are a number of classification systems for LPC but the most broadly used is the Modified Lateral Pillar Classification.

Essentially the greater the loss of lateral pillar height at the time of diagnosis relates well to overall outcome.

A –          Femoral Head affected but lateral Pillar preserved

B –           Upto 50% loss of femoral head height

B/C –      50% or greater loss of lateral pillar or overall height

C –           Greater than 50% overall loss of the femoral head height

The management of LCP depends on 2 main prognostic factors firstly changes that have occurred to the femoral head at diagnosis. Most type A and B will have favourable management outcomes. Type B/C have moderate outcomes so doing well and others less so. Type C generally can expect poorer outcomes.

Secondly the age at diagnosis. Before age 6 usually results in a good outcome, between 6-8 variable outcome but usually respond well to treatment and up to 80% have a favourable outcome. Greater than age 8 is usually associated with a poorer outcome.

Each case is treated individually based on a number of factors including changes of shape in the femoral head, age and prognosis in the longer-term.

In some cases, an Orthopaedic surgeon will need surgically re-align the head of the femur to best fit the cup in the pelvis – this is called an Osteotomy. For the greater majority of patient’s conservative therapy will involve anti-inflammatory medications and after this good rehabilitation from a Physiotherapist will focus on returning normal movement to the hip joint, strengthening the muscles to allow return to daily activities, then finally specific rehabilitation and progressive return to sporting activities.

https://patient.info/doctor/perthes-disease-pro accessed 28/04/2020

https://www.physio-pedia.com/Legg-Calve-Perthes Disease accessed 29/04/2020

Krieg A. Et al (2018) Legg-Calve-Perthes Disease and its Physiotherapy – “if the hip melts away”. HSOA Journal of Orthopaedic Research and Physiotherapy 3:37-41 DOI: 10.24966/ORP-2052/100037