Review Question - QID 5738

This patient has a complex proximal humerus fracture with metaphyseal comminution and poor bone stock. Cemented reverse total shoulder arthroplasty (rTSA) using a long stem prosthesis and tuberosity repair is indicated.

Proximal humerus fragility fractures are hard to treat because of comminution and poor bone stock. AVN is common with glenohumeral fracture-dislocation. Hemiarthroplasty (and standard total shoulder arthroplasty, TSA) is unreliable because of dependence on tuberosity healing. rTSA is recommended for fractures in patients >70 years with severely comminuted fractures, high likelihood of head AVN, and poor tuberosity bone quality (osteoporosis or comminution).

Bufquin et al. retrospectively reviewed the use of rTSA for treatment of 43 patients with 3- and 4-part proximal humerus fractures. They found satisfactory elevation (97°), ER in abduction (30°), constant scores (44) and modified Constant scores (66%). Complications included calcification (90%), tuberosity displacement (53%) and scapular notching (25%). They concluded that rTSA was a good procedure because it provides pain relief and easier functional recovery in spite of failed tuberosity healing.

Anakwenze et al. systematically reviewed acute proximal humerus fractures. Frequency weighted range of motion was flexion 122°, abduction 97°, ER at neutral 18°. Tuberosity repair yielded higher ER compared to no repair. Scapular notching was the most common complication (32%). They concluded that rTSA patients tended to be elderly women with 4-part fractures, had good pain control but residual dysfunction.

Jobin et al. reviewed rTSA for management of proximal humerus 3- and 4-part fractures. They note >50% of cases have tuberosity resorption. They recommend repairing the greater tuberosity to restore infraspinatus/teres minor function which improves external rotation strength. Greater tuberosity malunion is not a result of secondary displacement, but rather, from intraoperative malreduction. Lesser tuberosity repair should be performed if there is significant bone loss or intraoperative anterior instability.

Figures A and B are AP radiograph and 3D reformatted CT scan showing comminuted proximal humerus fracture dislocation. Illustration A shows rTSA performed with distal cementation of a long stem prosthesis and cerclage fixation of the proximal shaft and the tuberosity fragments.

Incorrect Answers:
Answer 1: ORIF has potential complications of screw cut out, AVN, fracture collapse, tuberosity resorption and loss of fixation. The risk of AVN (and resultant screw cut out) is high because of comminuted fracture-dislocation.
Answer 2: Cementing is indicated because metaphyseal fracture bone loss compromises stem fixation.
Answer 3: Greater tuberosity repair improves external rotation strength. Lesser tuberosity repair adds to anterior stability.
Answer 5: Proximal humeral replacement is only necessary for tumor or unreconstructable fractures. They have poorer outcomes because of loss of rotator cuff function.