# Lower Limb Osteochondrosis and Apopbysitis in Young Athletes--A Comprehensive Review
## 3 Osgood-Schlatter Disease: Presentation, Diagnosis, and Management  
Osgood-Schlatter disease (OSD) is a traction injury at the site where the patellar tendon attaches to the tibial tuberosity [24]. The onset of the disease coincides with the development of the secondary ossification center at the anterior tibial tuberosity (apopphyseal phase). The first symptoms typically occur in girls between the ages of 8 and 12 and in boys between the ages of 12 and 15 [25]. OSD is more common in athletes than non-athletes, with an incidence of approximately one in ten among athletic adolescents [26]. In addition, the prevalence is notably higher in males than in females, with a ratio of 14 to 1 [26]. Figure 1 shows a case of OSD in a young athlete. The image shows an uneven outline of the ossification nucleus of the apoplysis of the tibial tuberosity and increased vascular flow (red and yellow areas) of the patellar ligament. Figure 1: Osgood–Schlatter disease on the ultrasound image. (**a**) Irregular contour of the ossification center of the tibial tuberosity apopphys. (**b**) Increased vascularity at the attachment site of the patellar ligament observed on Power Doppler ultrasound. The literature indicates that OSD is one of the most common overuse injuries affecting the lower limbs, particularly in adolescents involved in sports that entail repetitive jumping or running, such as football [27; 28]. This condition is marked by pain of varying intensity localized to the tibial tuberosity, which is located just below the knee. The pain worsens with activities such as jumping, squatting, and kneeling, while resting usually relieves the discomfort [29]. The development of OSD is influenced by numerous factors, including, but not limited to, mechanical, morphological, functional, environmental, and psychosocial elements [26]. The most important of these factors are listed in Table 1.  
The diagnosis of OSD is primarily clinical and based on the presence of characteristic symptoms [38]. Clinicians typically evaluate the patient's history and physical examination findings, which may include irregularities at the tibial tuberosity, localized pain, tenderness below the knee, swelling, and potential pain exacerbated by physical activity, especially activities such as running, jumping, or kneeling [38]. In addition, a more detailed and functional examination by a physiotherapist may reveal pain that occurs with extension of the knee joint, along with tightness in the quadriceps and hamstring [39]. Importantly, although clinical assessment is essential, confirmation of the diagnosis by imaging studies, such as X-ray, ultrasound, and magnetic resonance imaging (MRI), is crucial to differentiate OSD from other knee pathologies, including fractures, tendinitis, and [PERSON]'s disease [26]. Radiographs can reveal changes in the tibial tuberosity, such as fragmentation or the presence of an ossicle in the patellar tendon [40]. Ultrasound helps to visualize the ossification center, tendon injuries, edema, and reactive bursitis [41; 42], while MRI reveals cartilage damage and early edema [23]. Other diagnostic methods, such as nuclear magnetic resonance (NMR), algometry, and thermography, are also noted in the literature for their potential role in the diagnosis of OSD [43]. The primary approach to treating OSD is conservative management, prioritizing activity modification, and ensuring adequate rest for recovery [40; 44]. These measures are expected to lead to a gradual reduction in pain symptoms and progressive improvement in functional outcomes over time. The available literature identifies several conservative treat