[Osteochondrosis dissecans and osteochondral lesions of the talus: clinical and biochemical aspects].
BACKGROUND
The natural course of osteochondral lesions of the talus are varied and the disease pattern is not clearly defined. There is an ongoing discussion among clinicians concerning the aethiopathology and the correct treatment.


METHODS
In this article all relevant studies are analysed with regard to aetiology, long-term outcome and the different established treatment options. Against the background of the current biomechanical understanding, an approach is made to this controversially discussed disease pattern utilising our own biomechanical laboratory results.


RESULTS
The available literature deals with longitudinal analyses regarding the natural history of the disease, conservative treatment, surgical options like debridement and anterograde drilling, retrograde drilling, osteochondral transplantation and autologous chondrocyte transplantation (ACT). Biomechanical trials describe high loads in the anterolateral parts of the joint. In most of the published studies the average age of the patients is around 28 years, younger patients have more favourable outcomes compared to older ones. In children the highest rate of spontaneous and advantageous course of the disease can be expected. Around 75% of the published outcomes relating to surgical therapy are satisfactory while 10% of the patients will suffer from osteoarthritis in the long term.


CONCLUSIONS
While the aetiopathology of the disease remains unclear, histopathological studies reveal subcortical bone necrosis. In 90% of the cases there is an ankle sprain in the past medical history although a direct correlation with trauma as exclusive trigger is not obvious. A possible approach is an osteochondral fracture in combination with an already existing osteonecrosis. A staged treatment regime is advised. In asymptomatic cases conservative treatment is advocated independent of the stage. Symptomatic patients with Hepple stages I, II and V and intact cartilage surface should undergo retrograde drilling in combination with a subchondral filling with cancelleous bone. If a cartilage defect is present (Hepple stages III, IV, V), an osteochondral transplantation is reasonable. Only if the defect zone is >2.5 cm2 should a debridement combined with a transplantation of cancellous bone and an ACT be considered. The sole anterograde drilling in our opinion should only be performed as an exception.
Katharinenhospital, Klinikum Stuttgart, Stuttgart. A.Suckel@Klinikum-Stuttgart.de
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Suckel
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Hoyer
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Raab
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Wünschel
D000843:Ankle Joint / Q000503:physiopathology*; D006801:Humans; D010008:Osteochondritis Dissecans / Q000175:diagnosis* / Q000503:physiopathology*; D055034:Osteochondrosis / Q000175:diagnosis* / Q000503:physiopathology*; D013628:Talus / Q000503:physiopathology*