Presentation
Fall at the races. Tender patella.
Patient Data
Age: 55 years
Gender: Male
From the case:
Fabella
{"study":{"id":25940,"case_slug":"fabella-1","modality":"X-ray","series":[{"id":5049206,"content_type":"image/jpeg","frames":[{"id":5049206,"width":972,"height":1529,"current":true}],"annotations":[],"encodings":{"original_dicom":null,"video":null,"thumbnailed_files":[{"tiny":"2573a5d9981480833cb8ca29a512fb_tiny.JPG","jumbo":"2573a5d9981480833cb8ca29a512fb_jumbo.JPG","small":"2573a5d9981480833cb8ca29a512fb_small.JPG","thumb":"2573a5d9981480833cb8ca29a512fb_thumb.JPG","medium":"2573a5d9981480833cb8ca29a512fb_medium.JPG","gallery":"2573a5d9981480833cb8ca29a512fb_gallery.JPG","big_gallery":"2573a5d9981480833cb8ca29a512fb_big_gallery.JPG","original":"2573a5d9981480833cb8ca29a512fb.JPG"}]},"perspective":null,"specifics":null}],"caption":{"us":null,"gb":null},"findings":{"us":"","gb":""},"contributor_login":"henryknipe","case_id":25793,"case_key_image_id":null,"case_featured_at":null},"current_user":null,"access":{"can_edit":false,"can_download":true,"can_feature":false,"can_pin":true}}
No fracture or malalignment. No definite knee joint effusion. Pre-patella soft tissue swelling consistent with bruising/hematoma given recent history of trauma. Incidental note of a fabella.
From the case:
Fabella
{"study":{"id":25941,"case_slug":"fabella-1","modality":"Annotated image","series":[{"id":5049214,"content_type":"image/jpeg","frames":[{"id":5049214,"width":972,"height":1529,"current":true}],"annotations":[],"encodings":{"original_dicom":null,"video":null,"thumbnailed_files":[{"tiny":"c26731f44d15a609aa0024589ca155_tiny.jpg","jumbo":"c26731f44d15a609aa0024589ca155_jumbo.jpg","small":"c26731f44d15a609aa0024589ca155_small.jpg","thumb":"c26731f44d15a609aa0024589ca155_thumb.jpg","medium":"c26731f44d15a609aa0024589ca155_medium.jpg","gallery":"c26731f44d15a609aa0024589ca155_gallery.jpg","big_gallery":"c26731f44d15a609aa0024589ca155_big_gallery.jpg","original":"c26731f44d15a609aa0024589ca155.jpg"}]},"perspective":null,"specifics":null}],"caption":{"us":null,"gb":null},"findings":{"us":"","gb":""},"contributor_login":"henryknipe","case_id":25793,"case_key_image_id":null,"case_featured_at":null},"current_user":null,"access":{"can_edit":false,"can_download":true,"can_feature":false,"can_pin":true}}
Red circle highlights the fabella.
Case Discussion
A fabella is a common accessory ossicle found in the lateral tendon of the gastrocnemius. It should not be confused for a fracture or an ossified intra-articular body.
Pre-patella soft tissue swelling is well seen on lateral knee radiographs and important to comment on as it is often clinically confused for a joint effusion.