Osteochondritis dissecans

MRI classification of juvenile osteochondritis dissecans lesions[33]Hefti F, Beguiristain J, Krauspe R, et al. Osteochondritis dissecans: a multicenter study of the European Pediatric Orthopedic Society. J Pediatr Orthop B. 1999;8:231-45. http://www.ncbi.nlm.nih.gov/pubmed/10513356?tool=bestpractice.com

Stage description:

1. Small change of signal without clear margins of fragment

2. Osteochondral fragment with clear margins but without fluid between fragment and underlying bone

3. Fluid is visible partially between fragment and underlying bone

4. Fluid is completely surrounding the fragment, but the fragment is still in situ

5. Fragment is completely detached and displaced (loose body).[Figure caption and citation for the preceding image starts]: Sagittal magnetic resonance image (MRI) of the talus, showing an osteochondral lesion on the posterior aspect of the talar domeGupta RK, Kansay R, Aggarwal V, et al. Osteochondritis dessicans of the talus in a 26-year-old woman. BMJ Case Reports 2009; doi:10.1136/bcr.06.2008.0091 [Citation ends].

Transchondral fracture of the talus[34]Berndt AL, Harty M. Transchondral fracture (osteochondritis dissicans) of the talus. J Bone Joint Surg Am. 1959;41:988-1029. http://www.ncbi.nlm.nih.gov/pubmed/13849029?tool=bestpractice.com

Stage description:

1. Small area of compression of subchondral bone

2. Partially detached osteochondral fragment

3. Completely detached osteochondral fragment remaining in the crater

4. Displaced osteochondral fragment.

Classification of osteochondritis dissecans of the capitellum[35]Difelice GS, Meunier MJ, Paletta GA Jr. Elbow injury in the adolescent athlete. In: Altchek DW, Andrews JR, eds. The athlete's elbow. Philadelphia, PA: Lippincott Williams & Wilkins; 2001:231-48.

Stage description:

• Ia-intact/stable: intact articular cartilage/no loss of subchondral stability

• Ib-intact/unstable: intact articular cartilage/loss of subchondral stability with impending collapse

• II-open/unstable: cartilage fracture/collapse or partial displacement of subchondral bone

• III-detached: loose cartilaginous fragment within the joint.

Classification of osteochondritis dissecans severity and stability of the osteochondritis dissecans fragment using arthroscopic and MRI findings[28]Guhl JF. Arthroscopic treatment of osteochondritis dissecans. Clin Orthop Relat Res. 1982 Jul;(167):65-74. http://www.ncbi.nlm.nih.gov/pubmed/7047040?tool=bestpractice.com ​​[29]Dipaola J, Nelson DW, Colville MR. Characterising osteochondral lesions by magnetic resonance imaging. Arthroscopy. 1991;7(1):101-4. http://www.ncbi.nlm.nih.gov/pubmed/2009106?tool=bestpractice.com

Stage description

• Stage I

  • Arthroscopic finding: irregularity and softening of cartilage. No fissure. No definable fragment.

  • MRI finding: no break, but thickening in articular cartilage.

• Stage II

  • Arthroscopic finding: articular cartilage breached but not displaceable.

  • MRI finding: articular cartilage breached, low signal rim behind fragment indicating fibrous attachment.

• Stage III

  • Arthroscopic finding: definable fragment, displaceable, but still attached partially by some cartilage (i.e., a flap lesion).

  • MRI finding: articular cartilage breached with high T2 signal changes behind fragment suggesting fluid behind the lesion.

• Stage IV

  • Arthroscopic finding: loose body and defect of the articular surface.

  • MRI finding: loose body with defect of articular surface.