# Lower Limb Osteochondrosis and Apopbysitis in Young Athletes--A Comprehensive Review
## 1 Introduction  
Young athletes represent a population group that is at increased risk for a variety of injuries. This is primarily due to their advancing skeletal development, which increases their susceptibility to trauma in the growth areas of the bones [1]. While these injuries may present similarly to those in adults, notable differences arise from the dynamic processes of bone growth in young people [2]. Key anatomical variations, including thicker and more remodeling-prone epiphyseal cartilage, increased susceptibility of the growth plate-metaphysis junction, the presence of apopbys (tendon attachment sites), and different growth rates of bone, muscle, and tendon, all contribute to the unique biomechanical pain and injury risks faced by young athletes [3; 4; 5]. Two fairly common conditions can be identified concerning injuries affecting the immature skeleton of young athletes, namely osteochondrosis and apopbysitis, both prevalent causes of pain in growing bones [6]. Apopbysitis is classified as an overuse injury that commonly occurs in active children and young athletes, especially those with tight or inflexible muscle-tendon units [7]. This condition results from repetitive traction forces acting on the cartilage and bony attachment sites of the tendons. The occurrence of apopbysitis is often associated with periods of rapid skeletal growth in which the elongation of the bones exceeds the elongation of the corresponding muscle-tendon structures [8]. Notably, the apopbyseal cartilage is approximately two to five times weaker than the surrounding soft tissues, including muscles, tendons, ligaments, and bones, making it particularly susceptible to injury [9]. Increasing inflexibility combined with the disproportion between bone and muscle growth exacerbates stresses at apopbyseal sites. In addition, the literature suggests that in lowerlimb apopphysitis, sports involving running and abrupt changes in direction can place significant mechanical stress on the hip, knee, and ankle joints, thereby contributing to the development of this condition in these regions [10]. In the context of apopphysitis, football is repeatedly highlighted in the scientific literature as the sport most frequently associated with this type of injury [11; 12]. [PERSON] et al. [13] reported that sixty-two growth-related sports injuries were documented during one football season, with apopphysitis being identified as the most common form. In addition, [PERSON] et al. [14] documented over four consecutive seasons that apopphysitis was the most common injury in young football players, with 239 injuries. It accounted for 21% of the total incidence and was the most stressful type of injury. Common conditions associated with apopphysitis, that have been documented in the scientific literature, include hip apopphysitis, [PERSON] disease (apopphysitis of the base of the fifth metatarsal), [PERSON] disease (apopphysitis of the tibial tubercle), [PERSON] syndrome (apopphysitis of the patella apex), and Sever's disease (apopphysitis of the calcaneal tuberosity) [15]. Osteochondraloses represent a heterogeneous group of diseases that affect the growth plates within the growing skeleton [16]. They typically result from traumatic or vascular pathologies and are often exacerbated by repetitive mechanical stress or overuse [17]. The pathophysiology of osteochondrosis is complicated and multifactorial, with the literature emphasizing the pivotal role of impaired blood supply to the growth cartilage as the main trigger [18]. This impairment of vascular perfusion leads to a cascade of pathologic events, including chondrocyte dysfunction, the development of fragile cartilage, and necrosis of the subchondral bone [18]. Although osteochondroses are generally self-limiting and regarded as relatively rare conditions, the underlying pathophysiological mechanisms remain poorly characterized. The current literature suggests a multifactorial etiology that includes genetic predispositions, hormonal dysregulation, recurrent microtrauma, and vascular abnormalities [19].