Perthes disease is a rare disorder whose most serious consequences can compromise the mobility of the hip. “The hip plays a pivotal role in providing mobility for our everyday life activities. Hip Disorders in children, such as Legg-Calvé-Perthes disease (LCPD), can adversely affect a child’s mobility and activity level. LCPD is a hip disorder that involves a vascular necrosis of the proximal femoral head. It is a relatively self-limiting disorder, in that some activities may need to be modified to ensure that excessive forces are not placed on the femoral head; however, failure to treat the condition may adversely affect regeneration of the femoral head. Because the etiology of LCPD is not completely understood, the best way to treat the condition is debated. Limitation of high-impact activities and rehabilitation that focuses on restoration of range of motion (ROM) is usually recommended.”1
“Legg-Calvé-Perthes disease (LCPD) is a childhood form of ischemic osteonecrosis of the femoral head, which afflicts 1 in 740 boys and 1 in 3500 girls between the ages of 2 to 14 years. The hip disorder can produce a permanent deformity of the femoral head and early osteoarthritis. The disruption of the blood supply to the femoral head produces the femoral head necrosis, but the etiology of the vascular disruption and the pathophysiology of the condition remain unclear. Interestingly, synovitis of the affected hip joint is a common feature of LCPD, which produces pain, loss of hip joint motion, and is associated with a poor clinical outcome. Very little research, however, has been geared toward delineating the mechanisms and the nature of the hip joint synovitis. The current clinical paradigm is that the synovitis is due to joint irritation from daily activities and overuse of the affected hip. As a result, the treatment strategy for the synovitis is nonspecific, focusing on decreasing activities and performing operative procedures that may not address the pathophysiology of the disease.”2
“As Legg-Calve-Perthes disease progresses, various deformities of the femoral head can develop. The most common are coxa magna (widening of the femoral head) and coxa plana (flattening). If the femoral head is damaged, it can result in premature physeal arrest which can lead to leg length discrepancy. A poorly formed femoral head can also lead to acetabular dysplasia and resultant hip incongruency. This can lead to altered mechanics and subsequent labral tears. Lateral hip subluxation or extrusion is a complication associated with a poor outcome and can lead to lifelong problems for the patient. A late complication of this childhood disease is hip arthritis.”3
Sometimes, surgical treatment is the best option. It occurs in children aged 4 to 12 years old when the head of the femur stops receiving blood. When there is no adequate blood supply, the bone goes through necrosis, a fancy word for tissue death, causing osseous fragility. As a result, pain and lameness in the child comes about. If Perthes disease progresses without treatment, the head of the femur regenerates again (the deteriorating bone gets absorbed by the body as it dies) with two possible results. On one hand, it could recover a rounded shape, or, the bone ends up deformed.
Evolution of Perthes Disease
- Phase 1: in the initial phase, there is a lack of blood flow in the femoral head and a consequent death of the bone. There is inflammation, stiffness and pain (but not always) in the joints of the hip and when viewing x-rays, the head of the femur looks irregular.
- Phase 2: this phase is known as the fragmentation phase, where the dead cells are reabsorbed and replaced by healthy new cells. It begins to regenerate and to acquire a rounded shape. This phase can last between 12 to 18 months.
- Phase 3: also called re-ossification phase, the head of the femur continues to recover an adequate shape and can take between 24 to 36 months.
- Phase 4: in the healing phase, normal bone cells replace those that went through fragmentation.
“The prevalence is four times more in boys and nearly 10-15% are affected bilaterally. The first presenting complaint is limping that is usually notice by parents. The second common complaint is pain mostly in the anterior hip and medial thigh, which may lead to antalgic gait. Range of hip motion may be affected with abduction and internal rotation being limited first, followed by a trendelenburg gait. In severe cases, adduction contracture may form. However, hip flexion and extension are rarely affected.”4
The causes of Perthes disease are unknown, although some researches point to a vascular origin. In addition, it is known that the probability of boys to suffer it is four times higher than girls. In most cases, only one hip is affected.
“Although described more than 100 years ago by four independent studies, the aetiology of Perthes’ disease remains poorly understood. LCP is between four and five times more common in boys than in girls, and children with this disease have delayed skeletal development of between one and two years. Approximately 90% of LCP cases are unilateral. In the most severe cases, LCP can lead to the permanent flattening of the femoral head, articular cartilage degeneration and early osteoarthritis.
An impairment or obstruction of the blood supply to the developing femoral head is thought to be the most likely mechanism for the disease. Factors leading to this vascular obstruction are unclear and are the subject to debate. During development, the epiphyseal blood supply is almost exclusively provided by the deep branch of the medial femoral circumflex artery (MFCA). Both imaging and histological studies have shown a partial or complete loss of blood flow and the development of ischaemic necrosi of the femoral head in Perthes’ disease. Furthermore, there is evidence of abnormal peripheral vasculature in children with LCP.”5
Generally, the child suffering from Perthes disease complains of hip pain but it is also possible that the pain occurs in the thigh and knee. The pain intensifies physical activity is performed and can disappear when resting. Most of the time, the child will have pronounced limpness.
“Clinical presentation can range from a painless limp to an “irritable hip.” Children may complain of knee pain that is referred from the hip. Limited range of motion, especially abduction and internal rotation, is present, occasionally with a Trendelenburg gait. Initial workup should include basic labs: CBC, ESR, and CRP, at a minimum. Additionally, an anteroposterior (AP) pelvic radiograph including both femoral heads, along with a frog lateral of the affected side, should be performed.
The differential diagnosis includes many conditions. The painful synovitis causing early symptoms in LCP can be clinically indistinguishable from transient synovitis, and initial radiographs can be negative. Distinct characteristics are described (Table 1), but follow-up radiographs are indicated to check for LCP even after symptomatic improvement. More important is the distinction between the irritable hip and a septic joint since the latter requires emergent treatment. Infectious etiology must be ruled out with reasonable confidence before attributing symptoms to synovitis.
One clue to the diagnosis of LCP is that bilateral involvement almost always demonstrates hips to be in different stages of disease. Symmetric involvement suggests other conditions, such as epiphyseal dysplasia, while atypical presentations should prompt consideration for osteonecrotic conditions, such as hypothyroidism, Gaucher’s Disease,21 glycogen storage defects, sickle cell anemia, and Meyer’s dysplasia. A skeletal survey can detect additional epiphyseal involvement. A hand radiograph for bone age determination assists in the differential as well, as LCP patients often have delayed bone age.”6
“Clinically, LCPD usually presents with limping and localized pain in the thigh and/or knee, occurring after sustained physical activity in a healthy child, and/or deficits in abduction and internal rotation, and Trendelenburg gait in advanced stages.
Plain X-ray is the most current additional diagnostic procedure in order to assess the stage of the disease, the containment of the femoral head in the acetabulum and the extent of capital involvement. The methods of treatment evolved during numerous decades, since the abduction casts and tractions until the advanced methods of surgical containment in order to obtain a spherical congruity of the hip joint, to restore range of motion and to prevent osteoarthritic deformity of the femoral head.
Indications for invasive treatment depend mostly on prognosis, which can be assessed during childhood or adulthood. Numerous factors have been studied in order to determine their involvement in the prognosis of LCPD.”7
The diagnosis of Perthes disease begins with a physical examination and a complete study of the child’s medical history. To confirm the diagnosis the doctor or specialist may suggest the following procedures: X-rays, magnetic resonance imaging (MRI) and a bone scan.
“MRI is a valuable tool in the evaluation of LCP disease that may be used to guide both nonsurgical and surgical management of the condition. This imaging technique can be used to document the presence of femoral head necrosis, accurately stage the disease process, provide important prognostic information, and diagnose a variety of associated complications. Contrast-enhanced MRI may prove to be particularly beneficial in the evaluation of suspected early (radiographically occult) proximal femoral epiphyseal necrosis and in the appraisal of femoral head revascularization. Radiologists should be aware of the various MRI findings of LCP disease, including the condition’s different stages. Early detection and treatment of LCP disease are imperative because they may prevent femoral head deformity, articular surface incongruity, and loss of containment, all of which adversely affect overall outcome. Finally, MRI may identify other causes of hip pain in the setting of suspected early LCP disease.”8
The treatment of Perthes disease varies depending on the severity of each case. Its main objective is to preserve the rounded shape of the head of the femur during the illness, while also controlling the pain suffered by the patient. In the initial phase, the treatment is based on analgesics. Among the main recommendations are bed rest, restriction of physical activity, avoiding the use of the affected limb and rehabilitation therapy.
“The goal of treatment is to avoid severe degenerative arthritis. Traditional treatment involves periods of bed rest, mobilization using walking aids, non-weight-bearing, abduction bracing, and surgical containment. Children under the age of 6 years usually have good results without major treatment interventions. Surgical containment involves a femoral, pelvic osteotomy, or shelf procedure that provides adequate coverage for the femoral head. The aim of treatment is to preserve and restore the femoral head and to relieve pain. There is debate regarding when surgical containment should be performed. It is difficult to predict the duration of the disease and the time at which revascularization of the capital femoral epiphysis occurs.”9
During advanced stages, the objective is to reshape the head of the femur so that the joint retains its ability to move. To achieve this, the doctor or specialist may suggest different methods. A more traditional treatment consists of using orthopedic splints to limit certain movements. This way, the head of the femur will be kept in a position that allows the bone to be properly accommodated. On the other hand, you can opt for surgical treatment to allow the head of the femur to be positioned correctly.
“The objective of treatment for Legg-Calvé-Perthes (LCP) is to prevent joint incongruity so as to delay osteoarthritic degeneration, the most dreaded complication of this disease. Over the past few years, the indications for treatment have been modified. Orthopedic treatment has not proven its efficacy and certain surgical treatments may have been ineffective or even worsened the condition.
The most current treatments, proximal femoral varus osteotomies or pelvic osteotomies, have long demonstrated their efficacy for recentering the femoral head within the acetabulum, the principle of LCP treatment. Nevertheless, these are interventions that are not without complications and inconvenience for the patient, with a long postoperative immobilization and the need for a second surgery to remove the material. Moreover, consensus has not been reached on the indications for these treatments.
Given these observations, it is logical to seek treatment that minimizes the risks of complication while reducing the side effects, which could be provided by augmentation acetabuloplasty using the shelf acetabuloplasty technique.”10
It is the orthopedic doctor who must decide which treatment is the most appropriate. You can also opt for physiotherapy to strengthen the muscles of the hip to stimulate movement.
(1) Wise, S. L., & Binkley, H. M. (2010). Current Management and Rehabilitation in Legg-Calvé Perthes Disease. Athletic Therapy Today, 15(4), 30-35. Available online at https://journals.humankinetics.com/doi/pdf/10.1123/att.15.4.30
(2) Kamiya, N., Yamaguchi, R., Adapala, N. S., Chen, E., Neal, D., Jack, O., … & Drissi, H. (2015). Legg‐Calvé‐Perthes Disease Produces Chronic Hip Synovitis and Elevation of Interleukin‐6 in the Synovial Fluid. Journal of Bone and Mineral Research, 30(6), 1009-1013. Available online at https://onlinelibrary.wiley.com/doi/pdf/10.1002/jbmr.2435
(3) Mills, S., Burroughs, K. E. (2019) Available online at https://www.ncbi.nlm.nih.gov/books/NBK513230/
(4) Mazloumi, S. M., Ebrahimzadeh, M. H., & Kachooei, A. R. (2014). Evolution in diagnosis and treatment of Legg-Calve-Perthes disease. Archives of bone and joint surgery, 2(2), 86. Available online at http://abjs.mums.ac.ir/article_3071_ce09c70b9dd0517343986d72549d0359.pdf
(5) Pinheiro, M., Dobson, C. A., Perry, D., & Fagan, M. J. (2018). New insights into the biomechanics of Legg-Calvé-Perthes’ disease: the role of epiphyseal skeletal immaturity in vascular obstruction. Bone & joint research, 7(2), 148-156. Available online at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5895949/
(6) Chaudhry, S., Phillips, D., & Feldman, D. (2014). Legg-Calvé-Perthes disease: an overview with recent literature. Bulletin of the NYU Hospital for Joint Diseases, 72(1), 18. Available online at https://pdfs.semanticscholar.org/3b11/5642511590eb9aafba4de6c69d087865c499.pdf
(7) Dillman, J. R., & Hernandez, R. J. (2009). MRI of Legg-Calve-Perthes disease. American Journal of Roentgenology, 193(5), 1394-1407. Available online at https://www.ajronline.org/doi/10.2214/AJR.09.2444
(8) Rampal, V., Clément, J. L., & Solla, F. (2017). Legg-Calvé-Perthes disease: classifications and prognostic factors. Clinical Cases in Mineral and Bone Metabolism, 14(1), 74. Available online at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5505718/
(9) Islam, Q. T., Siddiqui, M. R., Mustafa, E., Hossain, A., Rahman, M. Y. U., & Sina, H. (2013). Legg-Calve-Perthes Disease: A Rare Cause of Bilateral Avascular Necrosis of the Hip Joints. Anwer Khan Modern Medical College Journal, 4(1), 40-41. Available online at http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.873.3144&rep=rep1&type=pdf
(10) Pecquery, R., Laville, J. M., & Salmeron, F. (2010). Legg-Calve-Perthes disease treatment by augmentation acetabuloplasty. Orthopaedics & Traumatology: Surgery & Research, 96(2), 166-174. Available online at https://www.em-consulte.com/en/article/249717