The Limp family arrive at the emergency department with two of their children. Katie is a 10-year-old complaining of right foot pain. The pain has been getting worse over the past month, and she is now beginning to develop some stiffness. She is a keen athlete and trains five times per week. Her younger brother Michael is a six-year-old attending with progressive left hip pain.  Both children’s injuries were atraumatic, and they are systemically well.
Introduction
Osteochondrosis is a disorder of bone growth primarily involving the ossification centres at the epiphysis. It commonly begins in childhood and results in osteonecrosis of the growth plate, which can lead to altered bone and cartilage formation beyond the growth plate.
Although often confused with apophysitis, which is more clearly due to traction overuse injuries, osteochondrosis is often described as idiopathic osteonecrosis as no definite cause has been found. Some links show that genetic factors and high activity levels can increase a person’s risk of developing osteochondrosis.
History and examination
Osteochondrosis presents in a similar fashion independent of location. The symptoms will have a subacute onset with one or more of; joint pain, swelling or dysfunction. The patient may comment on symptoms worsening while stressing the site during activity. This is typical in throwing or gymnastics for Panner disease and weight-bearing activities such as running and jumping in lower limb osteochondrosis.
The joint involved may have mild swelling and tenderness. Other common findings are stiffness and a reduced range of motion. Active children will often seek medical attention once their pain and stiffness affect their sporting performance.
Important points to establish on history and exam are no sudden pain, absence of temperature, and no systemic complaints. This will help you consider important differentials, including osteomyelitis, malignancy, and stress fractures.
Investigations
X-ray is the diagnostic tool of choice. Findings depend on anatomical location and the stage of disease. Each location has its own radiological criteria, which can be quickly referenced online. MRI may be required in certain cases if the diagnosis remains unclear following initial imaging. Early typical X-ray findings are potentially normal. Radiological findings tend to show:
Initial findings
- Irregular epiphyseal growth
- Flattening of the epiphysis
- Soft tissue swelling
As disease progresses
- Sclerosis
- Fragmentation
- Joint destruction
Blood tests have no role in the diagnosis of osteochondrosis but will aid the work-up of possible differentials, including infection and malignancy.
Perthes Disease
A 10-year-old boy presents to the ED with progressive left leg pain. It has been progressing over the past few months with normal knee x-ray. The pain is now becoming localised to the hip. He has a hip x-ray performed which shows flattening of the femoral head with widening of the femoral neck. There is increased joint space and sclerosis at the physis. His x-ray shows advanced Perthes disease.
Panner Disease
A 13-year-old cricket player attends with elbow pain. The pain started gradually while bowling. He is now complaining of stiffness and pain, which is affecting his performance. His x-ray shows irregularity of the capitellum with associated sclerosis. These findings are consistent with a diagnosis of Panner disease.
Freiberg’s Disease
A 15-year-old female runner presents complaining of progressive forefoot pain while training.
Her x-ray shows a widening of the metatarsophalangeal joint. There is a flattening of the metatarsal head with cystic lesions. These findings are seen in Freiberg disease. Progressive disease will show sclerosis and increased cortical thickening.
Kohler Disease
A 9-year-old presents with worsening left foot pain. An X-ray revealed thinning and sclerosis of the navicular bone. This is typical for Kohler disease. You may see fragmentation in advanced cases.
Treatment
Osteochondrosis is self-limiting, and the bone will eventually revascularize to a certain extent. The goal of therapy is to facilitate maximal revascularisation while minimising long-term symptoms.
An appropriate treatment plan should be decided on a case-by-case basis and in conjunction with orthopaedics, physiotherapists, and the patients themselves. Although there is limited evidence to guide the type and length of treatment, some factors can help guide clinicians.
- Radiological stage: Each form of osteochondrosis has unique radiological staging criteria, which categorize disease progression on X-ray.
- Joint function: Patients range of motion and stiffness should be assessed. If there is a significant loss of joint function the patient should be treated more aggressively to prevent progression
- Patient symptoms: If the patient’s pain is significant, they may need some immobilisation to aid with pain prior to progression of their rehabilitation.
- Age at presentation: as a rough rule of thumb, the younger the patient’s bone age, the more likely they are to respond to conservative management.
Three broad treatment strategies exist.
Conservative: This will involve modified activity to ensure no further stress is placed on the area involved. A physiotherapy programme can help to strengthen the area and improve joint function. This approach is suitable for patients with minimal symptoms and early changes of disease progression on x-rays.
Immobilisation: Immobilisation can benefit patients with significant pain or more advanced changes on x-rays.  Depending on the area involved, this may be in the form of a cast, walking boot or splint. This needs to be weighed up against the risk of worsening joint stiffness.
Surgery: It is very rare, if ever, that patients will require surgery. It is only used in advanced stages of disease and when appropriate conservative management has proved ineffective. Surgical options include osteotomy, arthroplasty, and physeal drilling.
Prognosis
Osteochondrosis is a self-limiting pathological process. Patients usually show full clinical and radiological recovery if diagnosed and treated early. Despite this, some patients will continue to have long-term pain and stiffness; this can occur despite appropriate treatment plans.
This is especially true for Perthes Disease patients, who are at a high risk of arthritis and subsequently require a total hip replacement. One case series found that >50% of all Perthes Disease patients will require total hip replacement, with the mean age of initial total hip replacement being 37.8 years.
Bone age of <6 years and <50% femoral head involvement have been shown to be good prognosticating factors for Perthes.
The Limps are delighted with your assessment. Katie has been diagnosed with Kohler’s Disease. You placed her in a boot for four weeks to manage her symptoms. Following this, she underwent a specific return-to-activity regime to manage her training load and recovery. She is totally symptom-free at six months.
Michael is lucky that his diagnosis of Perthes was made early. His x-ray shows he is in the early stages with minimal femoral head involvement and good femoral head coverage. He is started on a physio programme with closely monitored clinical and radiographic assessment until full recovery.
Take homes
- Osteochondrosis is an idiopathic osteonecrosis affecting children
- It is diagnosed with a combination of accurate history and typical radiograph findings
- Early diagnosis and treatment can aid a complete recovery
- Bone age <6 years, <50% of femoral head involved and good femoral head coverage are good prognosticating factors for Perthes disease
Not to miss bits
- Differential diagnoses, including malignancy and infection, may present similarly
- Common systemic causes of osteonecrosis, such as haematological (sickle cell, malignancy) and rheumatological (SLE) causes, should not be overlooked.
- Although the pathophysiology of osteochondrosis is self-limited. If not treated promptly, it can result in long-term morbidity.
Controversies
- Potential causative factors include genetic links and repetitive activity.
- There are no firm directives regarding the length of treatments, including immobilisation.
- The benefits of surgery are variable and need to be considered on a case-by-case basis.
Selected references
Achar, S., & Yamanaka, J. (2019). Apophysitis and Osteochondrosis: Common Causes of Pain in Growing Bones. American Family Physician, 99(10), 610–618.
Claessen, F. M. A. P., Louwerens, J. K. G., Doornberg, J. N., van Dijk, C. N., Eygendaal, D., & van den Bekerom, M. P. J. (2015). Panner’s disease: literature review and treatment recommendations. Journal of Children’s Orthopaedics, 9(1), 9–17.
Terjesen, T., Wiig, O., & Svenningsen, S. (2010). The natural history of Perthes’ disease. Acta Orthopaedica, 81(6), 708–714.
Talusan, P. G., Diaz-Collado, P. J., & Reach, J. S. (2013). Freiberg’s Infraction: Diagnosis and Treatment. Foot & Ankle Specialist, 7(1), 52–56.
Olstad, K., Ekman, S., & Carlson, C. S. (2015). An Update on the Pathogenesis of Osteochondrosis. Veterinary Pathology, 52(5), 785–802.
Joseph, B. (2015). Management of Perthes’ disease. Indian Journal of Orthopaedics, 49(1), 10–16.
Masrouha, K. Z., Callaghan, J. J., & Morcuende, J. A. (2018). Primary Total Hip Arthroplasty for Legg-Calvé-Perthes Syndrome: 20 Year Follow-Up Study. The Iowa Orthopaedic Journal, 38, 197–202.
Chan, J. Y., & Young, J. L. (2019). Köhler Disease: Avascular Necrosis in the Child. Foot and Ankle Clinics, 24(1), 83–88.
