OSTEOCHONDRAL LESIONS ASSOCIATED WITH ANKLE FRACTURES: A Literature Review

Ankle fractures are among the most commonly encountered types of injuries in the lower extremity. Depending on the type of injury and its mechanism, open reduction with internal fi xation may be necessary. Typically, the main concerns with surgically repaired ankle fractures are restoration of fi bular length, restoration of joint congruity, and the stabilization of any concomitant syndesmotic injury. By meeting those objectives, the surgeon intends on maintaining long-term function primarily by reducing the possibility of post-traumatic arthritis. It is well understood that post-traumatic arthritis is a likely possibility given any intra-articular injury. Indeed, the literature supports this notion-post-traumatic arthritis is associated with approximately 12% of all encountered knee, hip, and ankle arthritis (1). Within the ankle joint alone, 7080% of arthritic joints may be attributed to post-traumatic etiology (2, 3), with post-traumatic arthritis resulting in 14-50% of all fractured ankles (4-7). This may be linked with multiple etiologies including malunion (potentially the most signifi cant), suboptimal reduction/alignment, ligamentous instability, and/or the development of arthrofi brosis (8-19). The treatment protocol for ankle fractures is relatively well agreed upon, with the above-mentioned variables also well agreed upon in considering the prevention of post-traumatic ankle arthritis. Interestingly, one etiology of post-traumatic ankle arthritis that has been somewhat overlooked in foot and ankle literature is the osteochondral lesion (OCL). A signifi cant amount of effort has been placed on researching OCLs of the ankle, including staging and surgical treatment. However, not as much focus has been placed on the etiology and the appropriate workup of such lesions. Bernt and Hardy’s original landmark publication outlined a basic rationale for the correlation between the mechanism of ankle injury and the type of OCL likely to be encountered (20), with anterolateral lesions linked to dorsifl exion-inversion injuries and posteromedial lesions linked to plantarfl exion-inversion injuries. This was a somewhat simplifi ed perspective, had a small cohort of only 24 patients (of which 9 of 24 [38%] had lesions), and the diagnosis of OCL was delayed. Typically, the thorough foot and ankle surgeon may initially consider the OCL as potential sequelae of ankle injury. There are a number of potential reasons, however, for this to be overlooked even for the experienced physician. To begin with, the clinical diagnosis of OCL can be diffi cult, especially when considering the presenting symptomology may not be easily distinguishable from that of the acute ankle fracture. The ordering physician does not usually obtain anything more than standard ankle radiographs in the workup of an ankle fracture, as this is usually enough to devise a treatment plan. Unfortunately, with the exception of larger lesions, standard radiographs are not inherently sensitive modalities for the diagnosis of OCLs and this can easily lead to an initial failure in identifi cation. Furthermore, magnetic resonance imaging and computed tomography, which are both much more sensitive and specifi c in their identifi cation of OCLs, are not typically ordered in the acute ankle fracture setting. Given the high incidence of post-traumatic osteoarthritis of the ankle, it is imperative that consideration be given to OCLs as a potential causative factor in poor longterm outcomes. Based on the literature, an ankle that has undergone ORIF may still experience a worse functional outcome in the long-term if a concomitant OCL goes undiagnosed at the time of injury.