## 2 Applications
### Ocd  
ODC are focal areas of damaged articular cartilage and subchondral bone. OCD are common sport-related injuries and can often deeply affect the patient's quality of life [21]. Intra-articular injuries are known to occur more frequently in an athletic population: compared with the general population, athletes place a higher demand on the joint surfaces and, as a result, are more likely to develop pathological conditions. Repetitive high-intensity loading during pivoting and twisting and acute contact trauma, especially in association with joint instability or deformities, can lead to OCD and/or rapid progression of cartilage injury [22]. This might explain why it is reported that osteoarthritis has a higher prevalence in former athletes [23]. Due to its poor restorative capacity, articular cartilage should be preserved in all its components: cells and extracellular matrix, together with subchondral bone. The primary treatment for talar OCD up to 1.5 cm in diameter is surgical [24]: even if well treated, these lesions may require as much as one year to obtain clinical improvement in the symptomatology. PEMFs can support surgical treatment to speed up functional recovery and achieve better outcomes. At the joint level, PEMFs perform a strong anti-inflammatory action and have a chondoprotective effect. In human osteoarthritis synovial fibroblasts, PEMFs inhibit the release of prostaglandin E2 (PGE2) and the pro-inflammatory cytokines interleukin-6 (IL-6) and interleukin-8 (IL-8), while stimulating the release of interleukin-10 (IL-10), an anti-inflammatory cytokine. These effects are mediated by the PEMFs-induced up regulation of adenosine A2A, 3 adenosine receptors [25]. Moreover, PEMFs counteract the interleukin-18 (IL-18) effect, thus increasing the synthesis of proteoglycans and proliferation of chondrocytes acting in concert with insulin-like growth factor-1 (IGF-1) present in both synovial fluid and articular cartilage; this plays a key role among the anabolic growth factors that control articular joint metabolism [26]. In addition, in human articular chondrocytes [27], PEMFs stimulation increase extracellular matrix component synthesis, such as collagen II (COLL II), glycosaminoglycan (Gags), and proteoglycans (PGs) [28]. Several studies have been published specifically reporting the use of PEMFs in surgically treated OCD. [PERSON] et al. reported the results of a prospective comparative study on patients with grade III and IV Outerbridge talar OCD managed with a collagen scaffold seeded with bone marrow-derived cells who randomly received postoperative biophysical stimulation with PEMFs (1.5 mT, 75 Hz, 4 h/day). Only one stimulation regime was used. A superior and significant clinical outcome was found in the PEMF group, with more than 10 points higher AOFAS score at the final follow-up. Authors concluded that PEMFs started soon after surgery-aided patient recovery, leading to pain control and better clinical outcomes [29]. [PERSON] and colleagues in a double-blind, randomized controlled trial evaluated the use of PEMFs (1.5 mT, 75 Hz, 4 h/day) after anthropogenic debridement and microfracture of talar OCD in athlete patients [30]. Although no differences in sport resumption one year after surgery between the treated and control groups were reported, in the PEMF-treated