Osteochondroses

Introduction

Osteochondroses are a group of 'diseases' of children and adolescents (typically) in which localized tissue death (necrosis) occurs, usually followed by full regeneration of healthy bone tissue. The singular term is osteochondrosis. (1) Osteochondroses are disorders of primary and secondary growth centres, or lesions at the apophyseal or epiphyseal growth areas of bones. (2)


During the years of rapid bone growth, blood supply to the growing ends of bones (epiphyses) may become insufficient, resulting in necrotic bone, usually near joints. Since bone is normally undergoing a continuous rebuilding process, the necrotic areas are most often self-repaired over a period of weeks or months.

Osteochondroses can affect different areas of the body and are often categorized by one of three locations: articular, non-articular, and physeal. (3)

Osteochondritis dissecans is a form of osteochondrosis in which loose bone fragments may form in a joint.

Aetiology

Many theories have been advanced to account for osteochondrosis, but none has proven fully satisfactory. Stress and ischemia (reduced blood supply) are two of the most commonly cited factors. Athletic young children are often affected when they overstress their developing limbs with a particular repetitive motion. Many cases are idiopathic.

The Eponyms

Most of the sites of osteochondrosis are known by eponyms. Amongst the Osteochondroses are the following.

Name	Site	Notes
Kienböck's Disease	lunate
Legg-Calvé-Perthes disease	hip- femoral head	commonly known as Perthes Disease
Scheuermann's disease	spine (thoracic)
Köhler's disease	tarsal navicular
Freiberg's Disease	Second metatarsal head	Commonly referred to as Freiberg's infraction because it was thought to relate to trauma
Osgood-Schlatter Disease	tibial tubercle	- 10 and 15 yr and is usually unilateral - related to sports activity
Panner's disease	capitellum of the elbow
Osteochondritis dissecans of the femoral condyle	femoral condyle- usually medial condyle
Sever's disease	calcaneum
Sinding-Larsen-Johansson syndrome	inferior tip of patella

Freiberg's Infraction

syn: Freidberg's Infarction, Freidberg's Disease

This condition was first described by Freiburg in 1914 as an infarction of the second metatarsal head. Freidburg's has the potential to affect any of the metatarsal heads. Radiographically a characteristic flattening of the head of the metatarsal can be viewed. This characteristic feature is known as the 'egg crush' appearance. Furthermore, the metatarsal head is prone to flaring and a trumpet like appearance.

5 Stage Classification

• Stage 1 Epiphyseal fissure fracture
• Stage 2 Central portion of bone re-absorption
• Stage 3 Metatarsal head begins to flatten
• Stage 4 Intra- articular loose body
• Stage 5 Complete flattening of the metatarsal head (4)

Typical osteonecrosis of the head of the second metatarsal seen in Freiberg's infraction	Note that central bone has undergone re-absorption.

Osteochondritis Dissecans of the Femoral Condyle (OCD)

- OCD is a defect in the subchondral bone of a joint with partial or complete separation of the bone fragment;
- most often seen in the medial femoral condyle (about 80% of cases), and less often seen in posterior aspect of lateral condyle;
- is usually unilateral (74%)
- relatively common source of loose bodies in the knee or even an incongruous joint if the separated fragment is large;
- twice as common in males;
- classically occurs below the age of 18 (range: 6 to 53 years) (5)

OCD of the medial femoral condyle. Note the subchondral bone defect (arrowed) in the medial femoral condyle and the associated loose bodies (arrowed)

Kienbock's Disease

- disease which involves collapse of the lunate due to vascular insufficiency and avascular necrosis;
- first described in 1910 by Kienbock (republished article in CORR 1980, Vol 149);
- disease occurs most often in young adults between 15 and 40 years;
- is usually unilateral;

<a class="external" href="http://www.wheelessonline.com/ortho/kienbocks_disease_lunatomalacia" rel="nofollow" target="_blank">Wheeless' Textbook of Orthopaedics</a>

Case 1

	This 27 year old male presented to the Emergency Department following a reinjury of his right wrist. His previous wrist injury was 2 weeks prior. There is evidence of a lunate fracture (arrowed). There is also evidence of sclerosis of the lunate suggesting that the patient has developed Kienbock's disease.
	The patient's injury was followed up 2 weeks later. The lunate showed little change in the previously noted sclerosis (left)
	Further imaging after a month suggested a possible increase in the previously noted lunate sclerosis (left)

Kohler's Disease of the Tarsal Navicular

Osteochondrosis of the tarsal navicular was described by Köhler in 1908. It is defined as a clinical condition consisting of:
1) pain in the region of the tarsal navicular, and
2) radiographic changes consisting of increased radiodensity, fragmentation and eventual narrowing of the tarsal navicular. .


Clinical features:
- child younger than 6 presenting with midtarsal pain
- Boys & girls, 4:1 in most reported series
- Pain with weight bearing / relieved by rest
- palpable tenderness over navicular (6)

This 3 year old girl presented with a spontaneous right sided limp. This comparison view was performed after the right foot image was reviewed.	The navicular appears small and abnormally dense. The pain and limp spontaneously resolved

Osgood-Schlatters Disease

- type of juvenile traction osteochondritis;
- refers to partial avulsion of the tibial tuberosity (anterior surface of apophysis) which has no
involvement of tibial physis;
- usually occurs in late childhood or early adolescence;
- more common in boys;
- may represent an over use disease;
- condition occurs at a time when increasing demands are made on a still immature skeleton;
- repetitive stress on tuberosity may cause partial avulsion;
- a painful non union will develop, if intervening gap fills with fibrous tissue rather than bone; (7)

Note the prominence, irregularity and fragmentation of the tibial tuberosity (arrowed).	Same patient- condition is bilateral.

Legg-Calvé-Perthes disease (LCPD)

Legg-Calvé-Perthes disease (LCPD) is the name given to idiopathic osteonecrosis of the capital femoral epiphysis of the femoral head.

Radiography

It is useful to produce comparable serial films. If you are not sure what views to do, check old imaging

• Initial investigation

AP Pelvis

• True AP
• Symmetrical internal rotation of femora
• gonad protection

Frogleg lateral

• a symmetrical positioning will facilitate comparison
• gonad protection

• Follow up

AP Pelvis or AP Hip

• True AP
• Symmetrical internal rotation of femora
• gonad protection

Lateral hip

• gonad protection

One of the earliest plain film features of Perthes disease is a subchondral fracture of the anterolateral aspect of the femoral capital epiphysis. This finding is best demonstrated on the frog-leg lateral projection.

Prognosis for the disease relates to the "ABC of Perthes"

A. Age of Onset	<5 Years: almost all do well. > 9 years: only 10-15% do well
B. Bone Growth	<a class="external" href="http://www.bgf.asn.au/textbook/structure_fuction/macro_bone/physis/physis.html" rel="nofollow" target="_blank">Physeal</a> involvement increases the chance of a poor sphericity at maturity.
C. Classification of extent of disease:	>50% of head involved have a poor prognosis. (8)

Classification Systems

A number of classification systems have been used in Perthes disease, and these have largely been based on plain film appearances

• Catterall
• Herring
• Salter-Thompson
• Stulberg

Mortality/Morbidity

• LCPD is a self-limited disease if not treated.
• Outcome is extremely variable.

Prevalence/Incidence/Sex Distribution

Sex

• Males are affected 4-5 times more often than females.

Age

• LCPD most commonly is seen in persons aged 3-12 years, with a median age of 7 years.

Plain Film Appearances

Five radiographic stages can be seen by plain x-ray. In sequence, they are as follows:

• Cessation of growth at the capital femoral epiphysis; smaller femoral head epiphysis and widening of articular space on affected side
• Subchondral fracture; linear radiolucency within the femoral head epiphysis (Crescent, Salter's or Caffey's sign)
• Resorption of bone
• Re-ossification of new bone
• Healed stage (9)

Note Sclerosis of left femoral capital epiphysis Decreased size of left femoral capital epiphysis linear radiolucency within the left femoral capital epiphysis. The focal area of resorption in the supero-lateral area of the femoral head is known as Gages sign and is thought to be an indicator of poor prognosis Acetabular changes widening of the articular space on the left side Alteration of pericapsular soft tissue outlines due to atrophy of ipsilateral periarticular soft tissues is seen in 73% of cases. (10)

Frogleg lateral small left femoral capital epiphysis linear radiolucency within the left femoral capital epiphysis Wide femoral neck widening of the articular space on the left side

Note later stage of disease right acetabulum changes widened right femoral neck smaller, sclerotic, flattened femoral subcapital epiphysis flattening of the femoral head predisposes the head to 'hinging' during movement

Scheuermann's Disease

• most common type of kyphotic deformity seen in adolescents
• deformity first described by Scheuermann in 1921
• Characterised by wedged vertebral bodies, irregular vertebral body endplates and increased thoracic kyphosis
• aetiology unclear- mechanical factors (lifting) have been implicated
• herniation of disc into vertebral bodies (Schmorl's nodes)
• narrowing of disc spaces

<a class="external" href="http://www.ajronline.org/cgi/content-nw/full/183/4/949/FIG12" rel="nofollow" target="_blank">http://www.ajronline.org/cgi/content-nw/full/183/4/949/FIG12</a>

Obeneba Boachie-Adjei and Vishal Sarwahi in Ronald L. Dewald., Spinal Deformities: The Comprehensive Text. Thieme, 2003

Wikiradiography Links

Osgood Schlatter disease

References

1. <a class="external" href="http://medical-dictionary.thefreedictionary.com/Osteochondroses" rel="nofollow" target="_blank">http://medical-dictionary.thefreedictionary.com/Osteochondroses</a>
2. S Orava and K Virtanen Osteochondroses in athletes, British Journal of Sports Medicine, Vol 16, Issue 3 161-168
<a class="external" href="http://www.healthofchildren.com/N-O/Osteochondroses.html" rel="nofollow" target="_blank">3. http://www.healthofchildren.com/N-O/Osteochondroses.html</a>
4 <a class="external" href="http://www.latrobe.edu.au/podiatry/Radiology/osteochondrosis.html" rel="nofollow" target="_blank">http://www.latrobe.edu.au/podiatry/Radiology/osteochondrosis.html</a>
5. <a class="external" href="http://www.wheelessonline.com/ortho/osteochondritis_dissecans_of_the_knee" rel="nofollow" target="_blank">http://www.wheelessonline.com/ortho/osteochondritis_dissecans_of_the_knee</a>

6. [MASON, MD, MILAN S. MOORE, MD Irregular Ossification of the Tarsal Navicular and Traumatic Midfoot Pain Presenting as Kohler's Disease of the Tarsal Navicular]
<a class="external" href="http://www.wheelessonline.com/ortho/osgood_schlatter_lesion" rel="nofollow" target="_blank">7. Osgood Schlatter Lesion, Wheeless' Textbook of Orthopaedics</a>
8. <a class="external" href="http://www.bgf.asn.au/textbook/diseases/perthes/perthes.html" rel="nofollow" target="_blank">BK Foster, EW Johnstone, Perthes Disease</a>
9. <a class="external" href="http://www.emedicine.com/emerg/topic294.htm" rel="nofollow" target="_blank">Geofrey Nochimson, MD Legg-Calve-Perthes Disease "emedicine"</a>
10. Dr Rajesh Sharma <a class="external" href="http://www.dograrad.com/?p=195" rel="nofollow" target="_blank">http://www.dograrad.com/?p=195</a>

Further Reading

• Waugh, W., The Ossification and Vascularisation of the Tarsal Navicular and Their Relation to Kohler's Disease, J Bone Joint Surg, 1958; 40-B:765-777.
• Williams, G.A. and Cowell, H.R., Köhler's Disease of the Tarsal Navicular, CORR, 1981; 158:53-58.