A 51-year-old male initially presented with a posterior fracture-dislocation of the left glenohumeral joint following episodes of seizures and a fall (Figure 1a and 1b). He underwent a shoulder hemiarthroplasty and presented two weeks after discharge, with pain and tense swelling of the upper left arm with a cutaneous haemorrhagic discharge with no significant history of trauma.
Ultrasound scans [Figure 2a and 2b] revealed a large haematoma deep to the deltoid. Spontaneous echo contrast with arterial flow was seen within. Given the above findings, we organised for an urgent CT angiography but it could not help with exact delineation of the pseudoaneurysm due to significant metal related artefact.
Repeat ultrasound ruled out possible spontaneous thrombosis and showed the haematoma with a liquefied 4 cm diameter component which demonstrated arterial flow. Imaging findings were suggestive of a pseudoaneurysm-, and a catheter angiogram was performed for confirmation and further management.
Upper limb angiogram confirmed a 37x32 mm pseudoaneurysm (Fig 3) arising from inferior circumflex humeral arterial branch. This branch was selectively embolised with Onyx 18. Post embolization angiograms demonstrated complete exclusion of the aneurysm (Fig 4).
The patient was followed up 2 weeks later by ultrasound which showed no arterial flow suggesting successful endovascular occlusion.
Shoulder hemiarthroplasty has several complications including instability, infection, implant loosening, and neurological deficits,[1] whilst vascular complications are extremely rare. On the other hand, a pseudoaneurysm is known to occur in 0.1% of cases of knee arthroplasty [2] and hip arthroplasty[3] as acute complications after arthroplasty, presumed to be due to direct injury or damage to the vessel wall by traction injury during arthroplasty.[3]
In the present case, a pseudoaneurysm of the posterior circumflex humeral artery occurred after shoulder hemiarthroplasty. The circumflex humeral artery arises medially from the axillary artery at the lower border of subscapularis and then travels posteriorly with the axillary nerve and circles the surgical neck of humerus. Pseudoaneurysms of the axillary artery after direct trauma [4] glenohumeral dislocation,[5] and pseudoaneurysms of the thoracoacromial artery after small incisions for an arthroscopic portal [6] and a loosened humeral resurfacing head [7] have been reported. Pseudoaneurysms of the posterior humeral circumflex artery have been reported in overhead throwing athletes [8], and the initial damage from compression of the vessels in the throwing position is believed to be the cause of the pseudoaneurysm.
The association between the development of the pseudoaneurysm and joint replacement remains hypothetical. We present, to our knowledge, the only reported case of a circumflex humeral artery pseudoaneurysm following shoulder hemiarthroplasty. A case of axillary artery injury secondary to shoulder dislocation has been described in literature,[9] where tension on the axillary artery due to dislocation and the artery being relatively fixed at the lateral margin causes the pectoralis minor to act as a fulcrum over which the artery is deformed.[10,11] For this case, the postulated mechanisms could be traction or repeated compression of the artery between loose components of arthroplasty over a protracted period. During the time of surgery, the patient may not have bled due to the prolonged compression and thrombosis/vasospasm.
The present case highlights a rare vascular complication of shoulder hemiarthroplasty which clinicians should be aware of, when a patient presents with a postoperative soft tissue swelling., Appropriate imaging with ultrasound and Doppler can help identify this complication when clinical signs and symptoms are nonspecific. Delayed recognition can lead to life-threatening bleeding due to rupture of psuedoaneurysm, infection as well as neurological deficits.
Circumflex artery pseudoaneurysm following shoulder hemiarthroplasty
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Based on the provided images (shoulder X-ray, postoperative upper arm color Doppler ultrasound, and angiography), the following main characteristics are observed:
Combining the patient’s medical history (posterior shoulder fracture-dislocation, postoperative hemi-shoulder replacement) with imaging findings, the possible diagnoses or differential diagnoses include:
Considering the patient’s age, medical history (shoulder fracture-dislocation and hemi-shoulder arthroplasty), onset of pain and bleeding skin exudate two weeks after surgery, and imaging findings (both Doppler ultrasound and angiography suggesting an arterial sac), the most likely diagnosis is a posterior circumflex humeral artery pseudoaneurysm.
Treatment Strategy Overview:
Rehabilitation/Exercise Prescription Recommendations:
After vascular management is completed and the risk of major bleeding is excluded, an individualized shoulder and upper limb functional exercise program can be formulated. It is recommended to perform these under the guidance of a professional rehabilitation physician, following the FITT-VP principles (Frequency, Intensity, Time, Type, Volume, Progression), in phases:
During the entire rehabilitation process, if there is any worsening pain, swelling, or signs of bleeding, activities should be reduced immediately, and re-evaluation should be performed to ensure safety.
Disclaimer: This report is a reference-based medical analysis derived from provided medical history and imaging data. It cannot replace necessary in-person consultations or professional medical advice. Clinical management should be tailored to the patient’s actual condition and carried out under the guidance of a specialist doctor.
Circumflex artery pseudoaneurysm following shoulder hemiarthroplasty
