To determine whether the Osgood-Schlatter lesion (OS) is produced by avulsion fracture or injury to the patellar tendon, all images obtained in 28 cases of OS in 20 patients (16 scintigrams, 34 computed tomographic [CT] scans, and 27 magnetic resonance [MR] images) were retrospectively analyzed. In 21 cases, imaging was performed before and after treatment; in 20 cases, relief from pain was complete at the time of repeat examination. In all patients (100%), abnormal size of the tendon, decreased attenuation, and increase in signal intensity were compatible with the CT and MR imaging appearance of tendinitis. Distended deep infrapatellar bursa was a frequent finding, particularly on MR studies. These abnormalities had partially disappeared at follow-up examination. An ossicle was seen in only nine of 28 cases (32%); in three of seven cases with follow-up, the ossicle remained nonunited to the tibial tuberosity on follow-up studies despite relief from symptoms. This implies that healing of fracture is not essential for relief from symptoms. These results strengthen the argument that in most cases of OS, insult to the tendon and associated soft tissues, rather than avulsion fracture, causes OS.

Magnetic resonance imaging (MRI) was performed in eight patients under the age of 8 years who suffered elbow fractures, to assess possible fracture extension into the distal nonossified epiphysis of the humerus in seven cases and to determine the displacement and location of the radial head in one case. MRI allowed accurate depiction of the fracture line when it extended into the cartilaginous epiphysis. In four cases, MRI findings were confirmed at surgery. In five cases, surgery was obviated because no articular extension of the fracture was seen on MRI (4 cases) or because no displacement was noted (1 case). In one patient, the plain film diagnosis of a Salter type II fracture was changed to Salter type IV on the basis of the MRI findings. It is concluded that MRI might play a role in the preoperative evaluation of pediatric patients presenting with elbow trauma when extension of the fracture cannot be determined with routine radiographic studies. Elbow injuries in children may be difficult to diagnose by routine clinical and radiographic techniques [1, 4, 12, 14]. Diagnostic difficulty is due to the presence of multiple ossification centers of the distal humeral epiphysis and proximal radius and ulna; these are mostly cartilaginous until the age of 11-12 years and therefore invisible on radiographs. Following distal radial and distal tibial physeal fractures, epiphyseal elbow injuries are the most frequent epiphyseal injuries [8, 16]. These fractures tend to be unstable and often require surgical intervention. In addition, lasting sequelae such as cubitus valgus and delayed ulnar nerve palsy can occur if these fractures are not treated properly [8].(ABSTRACT TRUNCATED AT 250 WORDS)