Ankle osteoarthritis affects 1% of the population and, unlike gonarthrosis or coxarthrosis, is secondary to previous trauma in more than 75% of cases. Another peculiarity of this disease is that it affects a younger and active population, with socio-occupational implications. Mechanical factors, such as incongruity, instability, malalignment, and impacts, which increase stress on isolated areas of the ankle cartilage, have been clearly associated with the development of osteoarthritis. However, we cannot ignore the importance of pro-inflammatory mediators present from the moment of fracture as triggers of the cascade that eventually causes chondrocyte cell death, ultimately responsible for ankle osteoarthritis.

The aim of this study is to systematically review the literature on clinical outcomes of patients who have undergone autologous matrix-induced chondrogenesis (AMIC) for treatment of osteochondral lesions of the talus (OCL) and compare the studies' outcomes. Pubmed and Embase were searched in January 2020 for articles concerning OCL surgery. Studies were included if they had a minimum 1-year follow-up and the primary measures were functional outcomes. The meta-analysis compared the Visual Analogic Score (VAS), the American Orthopedic Foot and Ankle Score (AOFAS), and the Foot Function Index (FFI) between baseline and follow-up of 1-2years, and 3-5years. A random effects model was used to evaluate outcome changes. The search returned 15 studies, with a total of 492 patients. The VAS improved 4.45 and 4.6 points from baseline to the 1-2year and 3-5yearfollow-up, respectively (p<0.001). AOFAS improved 31.59 and 32.47 points from baseline to the 1-2year and 3-5yearfollow-up, respectively (p<0.001). The FFI showed a significant improvement of 30.93 points from baseline to year 3-5 (p<0.001). A total of 6 patients with revision surgeries have been reported within the follow up period. It was not possible to correlate clinical features like lesion size, surgical approach, and bone marrow stimulation technique to the reported outcome. Surgical treatment of OCL via the AMIC procedure provided significant improvement in the functional outcome and pain scores when compared to the pre-operative values. Improvements were observed up to 5years post-operatively.

Despite the disabling nature of ankle osteoarthritis (OA), there is poor scientific evidence for a conservative treatment compared to the hip and knee OA. In this regard, most of the treatment options in use are not based on clinical studies of the ankle, and they are extracted from evidence obtained from clinical studies of other lower limb joints. However, this does not seem to be a good idea, since the aetiology of ankle OA is quite different from that of the hip or knee. Nonpharmacological and pharmacological treatments such as nonsteroidal anti-inflammatory drugs, hyaluronic acid, corticosteroid, platelet-rich plasma injection and mesenchymal stem cells injections have been reported. However, further research is required in this field to obtain a specific clinical practice guideline for the conservative treatment of ankle OA.