History

Fact Explanation
Age of presentation - 4 to 12 years This is the commonest age of presentation: between the ages of 4 to 12 years.[1] With the mean age of onset being 7 years of age. More common among boys, with a male to female ratio of 5:1.[1] The most significant prognostic factor is the age of onset; with a later onset (>8years) having a poorer prognosis.[2] It is also relatively more common among Caucasians and Asians and African populations show lower prevalence. The reason is thought to be due to anatomical differences in the blood supply to the head of the femur. Other risk factors are trauma during childhood and lower socio-economic class. [3]
Limping Likely to be the first symptom noticed by the care-giver. [4] Usually not incapacitating. [5] Occurs due the pain that is caused by avascular necrosis of the femoral head. May rarely present as bilateral disease.
Groin pain Usually noticed during the child's active play. The child will not be able to recount an instance where he/she got hurt. Though the pain originates in the hip it can also be felt in the groin and knee due to a phenomenon known as referred pain. [4]
Hip pain Occurs due to the ischemic necrosis of the femoral head. Children suffering from this disease have reduced blood flow and a reduction in the velocity of blood which is independent of vessel calibre.[6]
Anterior thigh pain Occurs as result of referred pain from the hip.[4]
References
  1. Pediatrics Clerkship. The University of Chicago. 2103 [viewed on 17 March 2014]. Available from: http://pedclerk.bsd.uchicago.edu/page/legg-calve-perthes-disease
  2. MAZDA K, PENNECOT GF, ZELLER R, TAUSSIG G. Perthes’ disease after the age of twelve years: Role of remaining growth. Journal of Bone and Joint Surgery (Br). 1999 vol-81-B:696-9 [viewed 17 March 2014]. Available from: http://www.boneandjoint.org.uk/highwire/filestream/16775/field_highwire_article_pdf/0/696.full-text.pdf
  3. ROWE SM, JUNG ST, LEE Lee, BAE BH et al. The incidence of Perthes’ disease in Korea, a focus on differences among races. Journal of Bone Joint Surgery (Br) December 2005 vol. 87-B no. 12 1666-1668 [viewed 17 March 2014]. Available from : doi: 10.1302/0301-620X.87B12.16808
  4. Legg-Calve'-Perthes Disease. National Osteonecrosis Foundation, Johns Hopkins University, 2000 [viewed 17 March 2014]. Available from: http://nonf.org/perthesbrochure/perthes-brochure.htm
  5. EVANS Donald L. Legg-Calve-Perthes’ Disease: A Study of Late Results. Journal of Bone and Joint Surgery (Br). May 1958 VOL. 40B, NO. 2 [viewed 17 March 2104]. Available from: http://boneandjoint.org.uk/highwire/filestream/20004/field_highwire_article_pdf/0/168.full-text.pdf
  6. PERRY Daniel C, GREEN Daniel J, BRUCE Colin E et al. Abnormalities of Vascular Structure and Function in Children With Perthes Disease. PEDIATRICS, July 1, 2012 Vol. 130 No. 1 e126 -e131 [viewed 17 March 2014]. Available from: 10.1542/peds.2011-3269

Examination

Fact Explanation
Reduced range of motion at the hip Occurs as a result of muscle spasm and pain. Markedly reduced range of motion especially in abduction and internal rotation. However when children are examined under anesthesia which oblivates pain, a normal range of motion is found. [1] During re-ossification the range of movement will improve.
Leg length discrepency Due to collapse of the femoral head after it undergoes avascular necrosis. [2]
Reduced muscle bulk of thigh, calf and buttocks Occurs due to disuse atrophy due to the pain and reduced range of movement at the hip, may have Trendelenberg's (waddling) gait. [3] Children with long-standing unresolved disease may even develop adduction contractures.
Irritability of the hip [4] Gentle rotation of the affected hip with the leg extended often demonstrates restriction to the rolling maneuver. [4]
References
  1. STANITSKI Carl L. Hip range of motion in Perthes’ disease: comparison of pre-operative and intra-operative values. J Child Orthop. Mar 2007; 1(1): 33–35.[viewed 17 March 2104] Available from doi: 10.1007/s11832-007-0009-5
  2. KARIMI Mohammad Taghi and MCGARRY Tony. A Comparison of the Effectiveness of Surgical and Nonsurgical Treatment of Legg-Calve-Perthes Disease: A Review of the Literature. Advances in Orthopedics Volume 2012 (2012), 7 pages. [viewed 17 March 2014]. Available from: http://dx.doi.org/10.1155/2012/490806
  3. KIM Harry KW. Legg-Calvé-Perthes Disease. J Am Acad Orthop Surg November 2010 ; 18:676-686. [viewed on 17 March 2104.] Available from: doi: 10.2106/JBJS.J.01725.
  4. BERRY Daniel J and LIEBERMAN Jay R. Surgery of the Hip. 1st edition. 2011. Elsevier.

Differential Diagnoses

Fact Explanation
Transient synovitis of the hip [1] May present with an acute limp in a child. Log rolling test will demonstrate a certain degree of irritability of hip. Will cause a transient self limiting irritability of the hip. While this is similar to Perthe's disease though it is of a shorter duration. Ultra sound and X-ray findings will help in differentiation. [2]
Slipped upper femoral epiphyses (SUFE) [1] Shows an older age of onset when compared to Pethes disease, usually between 9 to 15 years. Prefers to keep hip joint in flexion and external rotation. X-Ray radiograph will show 'Klein line.'[3]
Overuse syndromes [1] Pain and limping may occur due to inflammation of the hip joint. Overuse syndromes are common among children due to the softness of the growing bones and tightness of ligaments during growth spurts. Often seen in extremely active children and the pain is predominant on hip flexion. [3]
Non accidental injury (NAI) [1] May be caused by a fracture or due to malingering or Munchausen syndrome by proxy. Detailed information about the child's social background and a history of incompatible illnesses a pointer to this diagnosis. [3]
Septic arthritis [1] Child will be extremely toxic with high fever accompanied by chills and a loss of appetite. Movements will be grossly restricted at the affected joint. C- reactive protein (CRP) level will be extremely high, blood cultures may be positive while culture of joint aspirate is diagnostic. [3]
Acute lymphoblastic leukemia (ALL) [1] Bone pain occurs due to expansion of the bone marrow. Child will have other features of organ infiltration, anemia, leucopenia and thrombocytopenia. [3]
Bone tumour [1] Pain is usually described as being dull and achy. There is no change in the intensity of pain with activity and may often keep the patient awake at night. Tumor common in this age group is Ewing's sarcoma that occurs in the femur, pelvis, upper arm and ribs. [3]
Juvenile idiopathic arthritis (JIA) [1] Multiple joints may be affected with a long insidious course of the illness. A positive family history of joint disease and a raised ESR/CRP is pointer towards the diagnosis.
Functional limp [1] Is idiopathic and the child has no other limitation in activity. [3]
Appendicits [1] An inflamed appendix when in close contact with the psoas muscle or due to formation of a psoas abscess may cause limping. Right iliac fossa tenderness, migratory pain and other signs such as Rovsing's sign etc should be elicited. [3]
References
  1. Limping or non weight bearing child. Clinical Practice Guidelines, Royal Children's Hospital Melbourne, December 2012 [viewed 17 March 2014]. Available from: http://www.rch.org.au/clinicalguide/guideline_index/Child_with_limp/
  2. SAWYER Jeffrey R, KAPOOR Mukesh. The Limping Child: A Systematic Approach to Diagnosis. American Family Physician. February 2009. 1;79(3):215-224. [viewed 17 March] Available from: http://www.aafp.org/afp/2009/0201/p215.html
  3. ed CAMERON Peter, JELINEK George,EVERITT Ian. Textbook of Paediatric Emergency Medicine. 1st edition. Elsevier. 2006.

Investigations - for Diagnosis

Fact Explanation
X-Ray of the pelvis Anteroposterior view and Frog's leg lateral view should be sought.[1] Can be used to determine the radiographic stage of the disease. Four clinical stages have been described( by Waldenstrom) during the active phase of the disease: stage of increased radiodensity, the stage of fragmentation, the stage of reossification, and the healed stage. [2]
Bone scintigraphy Can detect changes in bone perfusion in early stages of the disease. [1] Changes can be seen X-ray changes and are also useful in assessing re-perfusion.
Magnetic resonance imaging (MRI) Gadolinium enhanced MRI may be used to quantify the extent of avascularity at the initial stage of the disease, while it may also be useful in understanding the degree of revascularisation As such this may be used as prognostic indicator of possible deformity. [1]
References
  1. BERRY Daniel J and LIEBERMAN Jay R. Surgery of the Hip. 1st edition. 2011. Elsevier.
  2. EVANS Donald L. Legg-Calve-Perthes’ Disease: A Study of Late Results. Journal of Bone and Joint Surgery (Br). May 1958 VOL. 40B, NO. 2 [viewed 17 March 2104]. Available from: http://boneandjoint.org.uk/highwire/filestream/20004/field_highwire_article_pdf/0/168.full-text.pdf

Management - General Measures

Fact Explanation
Bed rest with Bucks traction [1] This form treatment is recommended if passive hip abduction of 30 degrees or more can be achieved. [2] Goals of treatment is to splint the limb to reduce pain while containing the hip joint.
Ischial leg brace [1] Allows for ambulatory containment treatment of the patient. [3]
Snyder Sling [1] Good results can be obtained if treatment is instituted early. Principles are minimal weight bearing and immobilization of the joint. A sling can be used in uni-lateral disease. [4]
Containment approach Assumes that the most important aspect in treatment of Pethes disease is prevention of deformity of the femoral head. [1] With containment the femoral head is protected within the acetabulum. Containment position is defined as abduction and internal rotation of the extremity until the femoral epiphysis is well inside Perkins line. Several orthotic devices such as Newington brace, Toronto brace, Scottish rite brace, Broomstick plaster and Birmingham splint can be used in this method. [1]
References
  1. KARIMI Mohammad Taghi and MCGARRY Tony. A Comparison of the Effectiveness of Surgical and Nonsurgical Treatment of Legg-Calve-Perthes Disease: A Review of the Literature. Advances in Orthopedics Volume 2012 (2012), 7 pages. [viewed 17 March 2014]. Available from: http://dx.doi.org/10.1155/2012/490806
  2. CARNEY BT, MINTER CL. Nonsurgical treatment to regain hip abduction motion in Perthes disease: a retrospective review. South Med J. 2004 May;97(5):485-8.[viewed 17 March 2014]. Available from: http://www.ncbi.nlm.nih.gov/pubmed/15180025
  3. O'HARA JP et al. Long-term follow-up of Perthes' disease treated nonoperatively. Clin Orthop Relat Res. 1977 Jun;(125):49-56. [viewed on 17 March 2014]. Available from: http://www.ncbi.nlm.nih.gov/pubmed/880779
  4. SNYDER Clarence H. A sling for use in Legg-Perthes Disease. J Bone Joint Surg Am, 1947 Apr 01;29(2):524-526 [viewed 17 March 2014]. Available from : http://jbjs.org/article.aspx?articleid=10451

Management - Specific Treatments

Fact Explanation
Innominate osteotomy [1] Used to correct deficiencies in the alignment between the head of the femur and the acetabulum. The bones of the pelvis are reshaped or partially removed in order to realign the load-bearing surfaces of the joint.
Femoral osteotomy [1] The femoral head is reshaped in order to maintain alignment at the hip joint.
References
  1. KARIMI Mohammad Taghi and MCGARRY Tony. A Comparison of the Effectiveness of Surgical and Nonsurgical Treatment of Legg-Calve-Perthes Disease: A Review of the Literature. Advances in Orthopedics Volume 2012 (2012), 7 pages. [viewed 17 March 2014]. Available from: http://dx.doi.org/10.1155/2012/490806