Osteonecrosis of the humeral head
Postoperatively (2020-10), the X-ray findings were initially unremarkable. Just six months later (2021-04), the humeral head was deformed with collapse of the joint sphericity. A localized bright zone was found subchondrally directly adjacent to a joint level. Within a further three months (2021-07), this developed into a classic “crescent sign” on the deformed humeral head. This resulted in the diagnosis of humeral head necrosis.
Pathoanatomy: In humeral head osteonecrosis, there is ischemia with a focus in the peripheral, subchondral bone section. The ischemia is caused by occlusion of the intraosseous nutritial vessels, which are supplied by the anterior and posterior circumflex humeral arteries. Due to the retrograde course of the nutritial vessels, the subchondral zone of the humeral head is a vascular terminal zone (“last meadow”) with a predisposition to osteonecrosis.
An inverse shoulder prosthesis was implanted as treatment.
Further course: Eight months later (2022-03), the patient felt a severe, acute pain on the dorsal side of the right shoulder. This was the cause for a new X-ray diagnosis. What is the cause of the pain now?
