This patient presented with an 18 month history of right elbow pain following an injury whilst sailing. He recalled a jarring injury, where the elbow was hyperextended. There had also been some episodes of true locking of the joint. He had no complaints with any joints prior to this. There was no other significant past medical history. He had previously received an x-ray , but the results were not available at the time of his initial consultation. The patient reported that there was no indication of a fracture.
The elbow presented with a fixed flexion deformity, and no visible effusion on observation. There was full pronation and supination, and resisted tests were unremarkable. The patient reported a particular weakness when trying to extend the elbow. This appeared to primarily due to the disuse weakness and reduced range of movement.
On musculoskeletal ultrasound, the triceps muscle, musculotendinous junction and insertion onto the olecranon process appeared to be intact. Deep to the triceps muscle was a significant effusion within the posterior olecranon fossa of the elbow (Figure 1).
On moving the transducer medial and lateral but remaining in a longitudinal plane, I was able to identify small hyperechoic foci within the effusion visible in Figures 2 and 3. These appeared to move, with dynamic scanning during flexion and extension of the elbow.
The patient was referred for a right elbow MRI to clarify the condition of the joint. The report is as follows...
MRI report: Numerous ossified loose bodies are seen throughout the elbow joint highly suggestive of synovial osteochondromatosis. Mild osteoarthritis is also seen with some marginal osteophytes seen arising from the medial and lateral compartments. The joint space however, is reasonably well-preserved. No erosions are seen. There is a large joint effusion. The common flexor and extensor tendons are normal as are the biceps and triceps tendons.
Figures 4 and 5 demonstrate the loose bodies on the MRI images.
Synovial osteochondromatosis (SOC) is characterized by synovial membrane proliferation and metaplasia. Can also be termed synovial chondromatosis. The synovial lining of a joint, bursa or tendon sheath undergoes nodular proliferation, and fragments may break off from the synovial surface into the joint where they can ossify and enlarge.
I was also able to obtain the x-ray image retrospectively (Figure 6).
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