Glenohumeral hemiarthroplasty failure - overstuffing, glenoiditis, heterotopic ossification
Presentation
Pain and loss of range of motion.
Patient Data
Postoperative hemiarthroplasty. In the axillary region, there is a fragment at the lesser tubercle.
One year later
One year later high position of the prosthesis in the humerus, the residual neck, and the resulting lateralization of the tuberosity with “overstuffing”. New glenoid osteoarthritis with joint space narrowing.
Positioning a prosthetic head too far superiorly with joint space narrowing
Nine months later
Radiograph shows superior migration of the humeral head with decreased (< 2 mm) acromiohumeral distance due to overstuffing of the humeral component with rotator cuff massive tear, mainly involving supraspinatus and infraspinatus tendon. There is also an evident early glenoid erosion, superiorly, with coarse heterotopic ossification occurring at the infra-glenoid neck area.
Case Discussion
The superior margin of the humeral head is physiologically superior to the top of the greater tuberosity by 8-10 mm. The lateral humeral offset is the distance from the lateral base of the coracoid process to the lateral margin of the greater tuberosity. This distance is important because a significant decrease reduces the range of motion of the deltoid and supraspinatus muscles and the same, a significant increase causes excessive tension on the soft tissues (“overstuffing” of the joint), always with loss of motion. Also, a larger humeral component can lead to restriction of range of motion by increasing tension in the supraspinatus tendon. Glenoiditis is the most common complication of shoulder endoprosthesis with an erosion of the glenoid cartilage. Heterotopic ossification most frequently after trauma, neurological injury, burn, or previous surgery. The most common sites are in the anterior and posterior lower soft tissues and around the armpit.
Radiographer: TSRM Fabio Imola.