I-Acute avulsion fracture:
Pelvic apophyseal injuries are common in young football players. Apophyses, bony attachments of the tendons, are a common site of acute avulsion secondary to forceful muscle contraction. This might affect the anterior superior iliac spine, anterior inferior iliac spine (fig.1), ischial tuberosity (fig. 2), iliac crest and pubic bones, as well as the greater and lesser trochanters of the femur. A displaced avulsed bone fragment is diagnostic at plain X-ray or CT images. These injuries are usually managed conservatively with a good deal of rest allowing the muscle and bone to heal. Surgery is usually considered in case of significant displaced avulsion fractures. [5–7]
II-Chronic non-united avulsion:
In chronic non-union avulsion fracture (fig. 3), deformities, pseudoarthrosis and more serious complications like impingement might be encountered necessitating surgical correction.
III-Apophysitis:
Continuous muscle traction exerts stress on the apophyses (growing bone) resulting in chronic forms of injuries like in ischial apophysitis (fig. 4) and osteitis pubis (fig. 5). These chronic injuries are a source of chronic pain that might affect training and become concerning especially in young players seeking a career. X-ray is good at demonstrating bone changes in chronic cases, while MRI is more helpful demonstrating bone edema at the anatomical site of tendon attachment and further revealing aponeurotic, tendon, myotendon injuries. [2, 8–11]
IV-Muscle injuries
Muscle injuries are frequent in football players, mostly at the hamstrings, quadriceps, adductors and calf muscles. Ultrasound is a helpful primary imaging modality (fig.6). MRI remains the mainstay in diagnosis of muscle injuries, identifying precise anatomical location and pattern of injury that might range from interstitial edema without fibers distortion as in case of muscle strain, to more severe injury pattern with fibers and architecture distortion, laceration, gap (fig.7). The injury might be involving one or more of the following components: the muscle fibers, myoaponeurosis/fascia, myotendinous junction, tendon (fig.8) [12, 13].
Intramuscular degloving of the rectus femoris is a pattern of injury associated with kicking where dissociation of the inner (indirect head) and outer (direct head) muscle layers result in bull’s eye appearance at MRI (fig. 9) [14].
V-Heterotopic ossification
Heterotopic Ossification (HO) - Myositis Ossificans Traumatica (MOT) is a post traumatic complication affecting the muscles or tendons, commonly of the pelvic girdle and lower limbs of football players (Fig.10). This might occur following a major trauma or repeated microtraumas, presenting with pain (possibly intense in acute stage), discomfort, restricted muscle function or impingement syndromes. They are classified among the “don’t touch lesions”[15, 16].
VI-Internal hip derangement
Internal hip joint derangement with labrum tear and cartilage damage result in early osteoarthritis (fig. 11) [4, 17].