Osteochondritis dissecans (OCD) is the end result of the aseptic separation of an osteochondral fragment with the gradual fragmentation of the articular surface. It is often associated with intraarticular loose bodies.
Onset is between childhood and middle age, with the majority of patients being between 10 and 40 years of age, with approximately a 2:1 male to female ratio 3.
- repetitive throwing / valgus stress and gymnastics / weight bearing on upper extremity
- valgus stress / compressive force on the vulnerable chondroepiphysis of the radiocapitellar joint in skeletally immature patients is supported as the etiology for OCD of the capitellum 8
- ankle sprain / instability
- In the talus, 96% of lateral lesions and 62% of medial lesions were associated with direct trauma 9
- competitive athletics 10
- family history: epiphyseal dysplasia has been postulated as a subset of OCD 11
Symptoms are variable and range from asymptomatic to significant pain and locking (suggesting loose body formation). Joint effusions and synovitis are often present.
The exact etiology is uncertain, with the majority of cases thought to be the result of trauma 4. In up to 40% of cases, patients give a history of trauma as the inciting event 3. Other postulated causes include 4:
- avascular necrosis (AVN)
- fat emboli
- familial dysplasia
Many joints can be affected, but typical locations include:
- knee: femoral condyles are most common site accounting for ~95% of all cases: see osteochondritis dissecans of the knee
- ankle (talus): see osteochondritis dissecans of the ankle
- elbow (capitellum): see osteochondritis dissecans of the elbow
- shoulder (glenoid) 7
Plain radiographs should be the first step in the evaluation of knee pain, however, unless advanced changes are present and/or a meticulous technique employed, early findings of osteochondritis dissecans may be occult. The intercondylar "notch" view is very helpful.
Early findings include subtle flattening or indistinct radiolucency about the cortical surface. As the process progresses, more pronounced contour abnormalities, fragmentation and density changes (both lucency and sclerosis) become evident. If an osteochondral fragment becomes unstable and displaced, then donor site and intra-articular fragment may be seen.
CT has the advantage of sectional imaging through the joint and multiplanar reformats. Findings are similar to those seen on plain film.
MRI is the test of choice, with high sensitivity (92%) and specificity (90%) 4 in the detection of separation of the osteochondral fragment. This is essential in determining management.
- variable signal overall with intermediate to low signal adjacent to fragment and variable fragment signal
- the high signal line demarcating fragment from bone usually indicates an unstable lesion however false positives can result from edema 6
- low signal loose bodies, outlined by high signal fluid
- donor defect filled with high signal fluid
- high signal subchondral cysts
The four classic signs of instability described at MRI include14 :
(a) a high-signal-intensity rim at the interface between the fragment and the adjacent bone on T2-weighted MR image
(b) fluid-filled cysts beneath the lesion
(c) a high-signal-intensity lineextending through the articular cartilage over
lying the lesion
d) a focal osteochondral defect filled with joint fluid, indicating complete
detachment of the fragment.
- persistent pain with activity: ~ 2/3 following surgical management of knee and 40% following surgical management of elbow 12,13
- articular incongruity 13
- early degenerative joint disease 13
Treatment and prognosis
Spontaneous healing is usual unless there is an unstable fragment, and treatment revolves around rest and immobilization for up to a year 5.
When the fragment is unstable or displaced, without treatment patients are susceptible to premature secondary osteoarthritis. Numerous surgical approaches have been tried, including drilling, bone grafting, replacement of bone fragment and pinning 5.
When surgery is performed, the results in most cases are only "fair". 35-70% of patients achieve a "good to excellent" clinical outcome 3 but even in these cases, the majority develop osteoarthritis.
History and etymology
It was first described by the German surgeon Franz Konig in 1888.
- normal irregular distal femoral epiphyseal ossification
- avascular necrosis
- osteochondral impaction fracture
- stress/insufficiency fracture
- 1. Dähnert W. Radiology review manual. Lippincott Williams & Wilkins. (2003) ISBN:0781738954. Read it at Google Books - Find it at Amazon
- 2. Resnick D, Kransdorf MJ. Bone and joint imaging. W B Saunders Co. (2005) ISBN:0721602703. Read it at Google Books - Find it at Amazon
- 3. Michael JW, Wurth A, Eysel P et-al. Long-term results after operative treatment of osteochondritis dissecans of the knee joint-30 year results. Int Orthop. 2008;32 (2): 217-21. doi:10.1007/s00264-006-0292-7 - Free text at pubmed - Pubmed citation
- 4. Maeurer J. Imaging strategies for the knee. Thieme Publishing Group. (2006) ISBN:3131405619. Read it at Google Books - Find it at Amazon
- 5. Sailors ME. Recognition and Treatment of Osteochondritis Dissecans of the Femoral Condyles. J Athl Train. 1994;29 (4): 302-306. Free text at pubmed - Pubmed citation
- 6. De smet AA, Fisher DR, Graf BK et-al. Osteochondritis dissecans of the knee: value of MR imaging in determining lesion stability and the presence of articular cartilage defects. AJR Am J Roentgenol. 1990;155 (3): 549-53. AJR Am J Roentgenol (abstract) - Pubmed citation
- 7. Kevin E. Wilk, Michael M. Reinold, James Rheuben Andrews. The Athlete's Shoulder. (2018) ISBN: 9780443067013
- 8. The Extraosseous and Intraosseous Arterial Anatomy of the Adult Elbow *(dagger). (1997) The Journal of Bone and Joint Surgery (american Volume). 79 (11): 1653. Pubmed
- 9. Tol JL, Struijs PA, Bossuyt PM, Verhagen RA, van Dijk CN. Treatment strategies in osteochondral defects of the talar dome: a systematic review. (2000) Foot & ankle international. 21 (2): 119-26. Pubmed
- 10. Kocher MS, Tucker R, Ganley TJ, Flynn JM. Management of osteochondritis dissecans of the knee: current concepts review. (2006) The American journal of sports medicine. 34 (7): 1181-91. doi:10.1177/0363546506290127 - Pubmed
- 11. RIBBING S. The hereditary multiple epiphyseal disturbance and its consequences for the aetiogenesis of local malacias--particularly the osteochondrosis dissecans. (1955) Acta orthopaedica Scandinavica. 24 (4): 286-99. Pubmed
- 12. Steadman JR, Briggs KK, Rodrigo JJ, Kocher MS, Gill TJ, Rodkey WG. Outcomes of microfracture for traumatic chondral defects of the knee: average 11-year follow-up. (2003) Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association. 19 (5): 477-84. doi:10.1053/jars.2003.50112 - Pubmed
- 13. Bauer M, Jonsson K, Josefsson PO, Lindén B. Osteochondritis dissecans of the elbow. A long-term follow-up study. (1992) Clinical orthopaedics and related research. Pubmed
- 14. Tetyana Gorbachova, Yulia Melenevsky, Micah Cohen, Brett W. Cerniglia. Osteochondral Lesions of the Knee: Differentiating the Most Common Entities at MRI. (2018) RadioGraphics. 38 (5): 1478-1495. doi:10.1148/rg.2018180044 - Pubmed