Schlatter Disease

Schlatter Disease (Schlatter), is commonly called Osgood-Schlatter disease after the two authors who described it almost simultaneously in 1903 and considered it damage to the epiphyseal apophysis from which the tibial tuberosity develops. Schlatter disease belongs to osteochondropathies of juvenile age (see Perthes' disease), but has its own special features. Its theoretical interest lies in the special conditions of ossification of the epiphyseo-apophyseal cartilages. Its practical significance is evident from the fact that Schlatter disease is often encountered and easily confused with tuberculous or gummatous processes, although young people who are otherwise completely healthy become ill. In the 1890s, French authors described it as 'apophyseal osteitis' or 'osteomyelitis of growth.' Even earlier, in the 1880s, Danish and English authors considered Schlatter disease to be a characteristic traumatic periostitis of young soldiers and young athletes. Clinical picture. In adolescents aged 12-18 years, more often in boys, not only after bruising, falls, or physical exertion, but also without any external cause, pains begin with strong extension or extreme flexion of the knee, and a limited, dense, sharply painful swelling on pressure develops at the tibial tuberosity. The general condition is normal, local inflammatory changes are absent or weakly expressed. Often after one knee becomes ill, the other knee also becomes ill, with the same objective changes on the leg. Painfulness and pains last for months, exacerbating under the influence of mechanical impacts, gradually disappearing within a year, rarely later. The prognosis is entirely favorable. The bony prominence remains, but without any impairment of knee function. The diagnosis of Schlatter disease is based on a comparison of clinical and radiological data. The former have decisive importance, the latter may be absent in the initial stages of the process when only cartilaginous and tendon tissues, which are permeable to X-rays, are changed. The X-ray picture of Schlatter disease is less characteristic and more varied than in other osteochondropathies. First of all, it is necessary to take into account the numerous variants of normal ossification of the tibial tuberosity. From the epiphyseal plate of the upper end of the tibia at the age of 9-13 years, a beak-like process begins to descend downward, which later fuses with the metaphysis and forms a bony tubercle corresponding to the attachment on the leg of the quadriceps muscle. According to Licini, first a center of ossification appears at the posterior surface of the process. Then an independent center forms, sometimes two separate ones, below the apex of the cartilaginous beak-like process. Last of all, a center of ossification develops in the anterior part of the process. Depending on the intensity and direction of growth, on the shape and phase of fusion with each other of these 3 bony nuclei, the X-ray picture appears very diverse, resembling fragmentation, curvature and fractures of the epiphyseal apophysis. Significant separation and displacement of nuclei can be considered pathological; sharp changes in the shape and structure of the already ossified beak-like process; the apex raised forward more than 45° from the diaphysis; the formation of a protruding triangular spur, wedged into the metaphysis. Pathological anatomy. Histologically, the process is characterized by thickening of the cartilagous layer between the tibial metaphysis and the patellar ligament, irregular boundaries of the zones of ossification extending into the tendon tissue and forming a cellular fibrous cartilage, sometimes with a mucoid-type ground substance. The development of osteoid tissue, characteristic of rachitic processes, is not observed. Of particular interest are the findings of Yelenevsky, published by Gavrilenko, speaking in favor of secondary microtraumas. The pathogenesis of Schlatter disease has not been finally clarified. It can be said with certainty that this is a local process, connected with the conditions of epiphyseal-apophyseal development and ossification of the tibial tuberosity at a certain age. It is also beyond doubt that mechanical factors, repeated or excessive strains of the quadriceps muscle, play an essential role, modifying the process of bone formation morphologically and thereby causing functional disorders. The biology of growth cartilage and its specific reactions to ordinary harmful factors are still insufficiently studied. Therefore, the changes in Schlatter disease do not fit into the framework of ordinary inflammatory, degenerative or restorative processes. Rather, this is possible with gross traumas with avulsion or fracture of the tibial tuberosity. Such cases have been described rarely. They have no direct relation to Schlatter disease. Therapeutic and preventive measures. To prevent the development of Schlatter disease, physical education activities of young people should be under medical supervision. At the first appearance of symptoms, it is important to exclude secondary trauma by appropriate regimen and wearing patellar straps. In cases with severe pain, removable-immobilizing bandages are indicated, preferably starch-cardboard ones; along with this, heat procedures (solux) and irradiation with a quartz lamp. Surgical interventions can accelerate recovery and should consist in a longitudinal incision of the patellar ligament with the removal of excess epiphyseal apophysis and displaced centers of ossification.