A 7-year old youth soccer player presented with periodic pain and slight swelling of his right elbow since two months, without previous trauma. There was a limited range of motion in the elbow.
Conventional radiography showed joint effusion, irregular contours of the capitellum, increased bone density and a thin radiolucent line in the subchondral bone (Figures 1a and 1b). Follow-up with Cone Beam CT 2 months later depicted a crescent with vacuum phenomenon in the subchondral bone (Figures 2a and 2b), corresponding to the radiolucent line seen on radiographs.
Subsequent MRI revealed intact articular cartilage of the capitellum, predominantly low signal of the capitellum on both T1- and PD weighted images in keeping with sclerosis, and bone marrow edema in the adjacent humeral bone on FS PD weighted images (Figures 3a, 3b, 3c and 3d).
Panner’s disease represents an osteochondrosis of the humeral capitellum. Osteochondroses affect epiphyses or epiphyseal equivalents and their progression ceases with skeletal maturity of the affected part [1]. Panner’s disease occurs most frequently in boys under the age of 11 [2, 3].
Microtraumata from repetitive valgus stress and increased axial load are incriminated as the main pathogenetic factors, typically occurring in throwing sports and gymnastics respectively [2].
This may lead to disruption of vessels that supply the nucleus of the capitellar ossification centre, leading to ischemia, resulting in disturbed endochondral ossification [2].
Clinical presentation consists of pain, stiffness, swelling and a limited range of motion – especially an extension deficit, flexion deficit is less common [2]. The pain is activity-related [2].
Conventional radiographs may show an irregular contour, sclerosis, subchondral radiolucency, fragmentation and flattening of the capitellum [2, 3].
As the radiographical changes may be subtle, a low dose (Cone Beam) CT may be beneficial because of its greater sensitivity for detection of subtle changes and characterization of a subchondral vacuum phenomenon [4].
The radiolucent subchondral crescent represents gas accumulation in a subchondral fissure, which indicates osteonecrosis and impending articular collapse [4, 5]. This vacuum-phenomenon disappears when repair and re-ossification occurs [4].
MRI shows heterogeneous signal intensity due to a variable degree of sclerosis, vacuum phenomenon and bone marrow edema in the ossified part of the capitellum, while the overlying cartilage is normal [2, 4]. The vacuum phenomenon has a similar low signal as the sclerotic changes and is therefore difficult to detect on MRI.
The majority of patients can be successfully treated conservatively, without serious morbidity [2].
The differential diagnosis of Panner’s disease consists of osteochondrosis dissecans (OCD), which is seen in the second decade of life, when the ossification of the capitellum is complete [3, 5]. OCD affects both bone and overlying cartilage and may be complicated by intra-articular loose body formation and has an overall poorer outcome [2, 3]. MRI may detect cartilage defects, therefore it will be useful for distinguishing between Panner’s disease and OCD.
Our patient was treated conservatively, with rest, avoidance of weight bearing and of leaning upon the right arm, promotion of passive movement and antiphlogistic medication. After six months there was a significant clinical improvement and a partial regression of radiological abnormalities.
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Panner’s disease.
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Based on the provided X-ray, CT, and MRI images, the following findings are observed:
Considering the patient’s age (7 years), symptoms (chronic dull pain, restricted range of motion), and imaging features (sclerosis, fragmentation, vacuum sign of the humeral capitellum, and intact cartilage), the primary possible diagnoses include:
Taking into account the patient’s age, clinical symptoms (chronic elbow discomfort, restricted motion, typical history of throwing or weight-bearing activities), and imaging findings (subchondral sclerosis, fragmentation, vacuum sign in the humeral capitellum, with no major cartilage damage), the most likely final diagnosis in this case is:
Osteochondrosis of the Humeral Capitellum (Panner’s Disease).
For Panner’s disease, since the patient’s skeletal system is still developing, most cases can be managed with conservative treatment and a rehabilitation plan as follows:
Disclaimer: This report is a reference-based analysis of the information provided and does not replace an in-person consultation or professional medical diagnosis and prescription. If you have any concerns or worsening symptoms, please seek medical attention promptly.
Panner’s disease.
