# Legg-Calve-Perthes disease - Category: chronic - Review status: reviewed (every claim checked against a document named on this page) - Sources: Legg-Calve-Perthes Disease - StatPearls (NCBI Bookshelf NBK513230) - https://www.ncbi.nlm.nih.gov/books/NBK513230/ · Legg-Calve-Perthes disease - disease-level clinical article (perthes-disease-full.txt) · Legg-Calve-Perthes disease - disease-level clinical article (perthes-disease-clinical.txt) - Verified date: 2026-08 ## Verified against - Legg-Calve-Perthes Disease - StatPearls (NCBI Bookshelf NBK513230) - https://www.ncbi.nlm.nih.gov/books/NBK513230/ - Legg-Calve-Perthes disease - disease-level clinical article (perthes-disease-full.txt) - Legg-Calve-Perthes disease - disease-level clinical article (perthes-disease-clinical.txt) ## Treatment metadata - Referral & safety-netting (no drug therapy) ## Complete treatment card ```text LEGG-CALVE-PERTHES DISEASE Sources: Legg-Calve-Perthes Disease - StatPearls (NCBI Bookshelf NBK513230) - https://www.ncbi.nlm.nih.gov/books/NBK513230/ · Legg-Calve-Perthes disease - disease-level clinical article (perthes-disease-full.txt) · Legg-Calve-Perthes disease - disease-level clinical article (perthes-disease-clinical.txt) Review status: REVIEWED against 3 sources listed above (2026-08) IS IT THIS? - reference only, to read alongside your own examination SYMPTOMS - what the patient reports (5) - A painless or mildly painful limp in a 4 to 10 year old that worsens with activity and eases with rest is typical [limp] - Hip or groin pain that refers to the knee can misdirect the initial evaluation toward the knee [groin pain · hip pain] - The absence of fever or systemic illness helps separate this from an infectious cause of hip pain [groin pain · hip pain] - It is an avascular necrosis of the growing femoral head, with no cause ever found [necrosis] - Boys are affected far more often than girls SIGNS - what you find (5) - An antalgic or Trendelenburg gait with restricted hip abduction and internal rotation is characteristic - A shortened leg on the affected side can result from femoral head collapse [collapse] - Both hips are affected in 15% to 20% of cases, sometimes with subtle early findings - The head of the femur can deform if it is not kept contained inside the socket - Red flag: a head that does not heal round and congruent risks femoroacetabular impingement and osteoarthritis early in life TESTS (4) - Early radiographs may look normal or show subtle epiphyseal density change, while later films show fragmentation and lateral pillar collapse - A crescent sign on X-ray marks a subchondral fracture - MRI can pick up marrow changes and lost blood supply earlier than plain X-rays can - Blood tests are typically normal and are mainly used to rule out infection or inflammatory arthritis IF NOT THIS - what else fits (3) - Fever or elevated inflammatory markers point away from Perthes toward septic arthritis, osteomyelitis, or inflammatory arthritis - Age at onset, the pattern of femoral head involvement, and systemic symptoms help separate Perthes from slipped epiphysis, transient synovitis, septic arthritis, or JIA - MRI is particularly useful to tell Perthes apart from transient synovitis, early slipped epiphysis, or infection Source Legg-Calve-Perthes disease - disease-level clinical article (perthes-disease-full.txt) Status traced to the source above 1. REFERRAL & SAFETY-NETTING (NO DRUG THERAPY) [1st line] Adult Source Legg-Calve-Perthes Disease - StatPearls (NCBI Bookshelf NBK513230) - https://www.ncbi.nlm.nih.gov/books/NBK513230/ Why Legg-Calve-Perthes disease is a slow, painless-to-mildly-painful limp in a young child that ends in a deformed femoral head if containment is lost. Primary care recognises it and X-rays the hips; the containment decisions belong to paediatric orthopaedics. No drug is offered below because no medicine changes the course. Caution THE PICTURE IS A YOUNG CHILD WHO LIMPS WITHOUT COMPLAINING MUCH - Perthes creeps up rather than announcing itself. What parents describe is a limp in a child of 4 to 10 years with little or no pain in it, worse after activity and better with rest. AND THE PAIN IS OFTEN IN THE KNEE - where it hurts is usually the hip or the groin, and it commonly refers down to the knee, which is what sends the assessment off in the wrong direction. The history to take: pain in the hip, the groin, the thigh or the knee that comes on with activity - and sometimes knee pain and nothing else. NO FEVER, NO ILLNESS - AND IF THERE IS, IT IS NOT PERTHES - there are no systemic signs in Perthes: no fever, no redness, no raised inflammatory markers. Find any of those and look instead for septic arthritis, for osteomyelitis, or for an inflammatory arthropathy. WHAT TO FIND ON EXAMINATION - a gait that is antalgic or Trendelenburg. Hip movement restricted, abduction and internal rotation worst of all, with a flexion contracture and loss of full extension developing in time. Pain at the ends of the range, abduction and internal rotation again. And, once it has run a while, wasting of the thigh and the buttock. X-RAY BOTH HIPS, AND ACCEPT THAT EARLY FILMS CAN BE NORMAL - the standard pair is an AP view of the pelvis and a frog-leg lateral. At the very earliest stage all there may be is a capital femoral epiphysis that looks slightly denser or smaller than its fellow, or an effusion in the joint - and the films can be entirely normal. MRI picks up early disease more readily than plain radiography does. REFER EARLY, BECAUSE THE WINDOW IS THE SHAPE OF THE HEAD - parents, and whoever sees the child first in primary care, need telling that a limp which persists, or hip, groin, thigh or knee pain brought on by activity, warrants assessment without delay, hip films included. Diagnose it early and the containment strategies can start before the head has deformed badly. WHAT THE SPECIALIST IS TRYING TO ACHIEVE - what decides the outcome years later is how round the femoral head is at skeletal maturity, and how well it fits the acetabulum. So the management aims to keep the femoral head contained within the acetabulum, or to get it back there, and to preserve the range of hip movement - abduction and internal rotation above all. AGE AT ONSET IS THE BIGGEST PROGNOSTIC LEVER - a child under 6 years, and especially one whose disease is mild (Herring A, and some B), usually does well without an operation. A child over 8 years, and one whose head is more extensively involved (Catterall III-IV; Herring B, B-C or C), is at greater risk of a poor result and is likelier to gain from surgical containment, provided the hip still moves adequately. TELL THE FAMILY HOW LONG IT TAKES BEFORE THEY ASK - explain that the natural history is a long one, typically 2 to 4 years, and that it means repeated films and repeated examinations. The family should grasp that the aim is a hip that is well shaped and lasts, not symptoms gone quickly. IT IS NOT A BENIGN LIMP THAT WEARS OFF - Perthes heals itself, but that is not the same as harmless. What deformity remains shows as coxa magna, the femoral head enlarged; coxa plana, the head flattened; and a head no longer spherical on a shortened femoral neck with the offset reduced. CHECK THE OTHER HIP TOO - both hips are involved in 10% to 24% of patients, though not necessarily at the same time. Where it is bilateral, the two sides may look alike or may follow one another, and early on the changes can be very slight. THE OTHER LIMPING-CHILD DIAGNOSES TO HOLD BESIDE IT - the article's own differential is transient synovitis, septic arthritis, juvenile idiopathic arthritis, and a slipped capital femoral epiphysis. Age is the first sorter: Perthes belongs to the 4-to-10-year- old, a slipped capital femoral epiphysis to the heavier adolescent. Both send their pain to the knee. SMOKE IS THE ONE RISK A FAMILY CAN ACT ON - counsel families firmly to keep the child away from tobacco smoke, in pregnancy and through childhood. Prices are indicative (dataset snapshot 2026-06); verify with the pharmacy. ``` --- Dawaa Reference is a reference for prescribers, not a medical device, and does not replace clinical judgement. [Privacy policy](/privacy)