Management of the Failed Arthroplasty for Proximal Humerus Fracture

Djuro Petkovic, MD; David Kovacevic, MD; William N. Levine, MD; Charles M. Jobin, MD

Disclosures

J Am Acad Orthop Surg. 2019;27(2):39-49. 

In This Article

Failure of Reverse Arthroplasty for Fracture

Reverse arthroplasty for acute proximal humerus fracture has become increasingly popular in select patients older than 70 years because of a predictable return to good function without the dependency on tuberosity healing. However, postoperative complication rates are as high as 45% in RTSA, with complication rates for fracture as high as 36%.[1] These complications, which are similar to other diagnoses managed with this prosthesis, include dislocation, baseplate failure, loosening, scapular notching, acromial fracture, deltoid fatigue, nerve palsy from over lengthening or iatrogenic injury, and infection. Unique complications for fracture include higher rates of heterotopic ossification, reflex sympathetic dystrophy, and periprosthetic fracture.[34] Revision of a failed RTSA for fracture is dependent on the mode of failure, but is especially difficult if the glenoid bone stock is deficient. Additionally, clinical outcomes are jeopardized if axillary nerve dysfunction or notable deltoid deficiency is present.[35]

Management of the unstable RTSA usually includes a closed reduction and 6 weeks of immobilization for first time dislocation so long as there are no problems with component version, fixation, or concern for infection. For recurrent dislocation, surgical intervention typically requires increased soft-tissue tension, increasing polyethylene thickness, restoration of the lateral offset of the humerus by increasing the glenosphere diameter, or lengthening by adding a spacer to the humeral stem. Inadequate soft-tissue forces and prosthetic compressive forces are the most important factors to increase stability. Other factors to consider include impingement from heterotopic ossification and liner failure.[36]

Management of baseplate failure may include staged surgery with bone autografting of the glenoid defect, followed by revision baseplate fixation.[37] Single-stage revision of baseplate fixation is also possible when there is a contained defect with intact medial vault or base of the scapular spine for central long peg placement. Single-stage revision requires careful preoperative planning by obtaining a CT with 3D reconstruction to define screw trajectory, baseplate placement, and the need for structural allografting. If inadequate glenoid vault remains for central fixation, then the baseplate may be positioned to have the central post or screw gain fixation in the base of the scapular spine. In cases with more severe glenoid bone loss, experimental glenoid component designs exist similar to hip arthroplasty systems that use multiple points of fixation in the scapula and have had success for revision of the failed RTSA at 3-year follow-up.[38]

Management options for PSI after RTSA are complex as noted previously. One study found improved function and symptomatic relief without component loosening after débridement and polyethylene exchange compared with resection.[39] Although resection is a viable palliative option for failed arthroplasty to reduce shoulder pain, shoulder function will be detrimentally affected. Resection of RTSA has worse outcomes than resection after hemiarthroplasty or anatomic shoulder arthroplasty.[40]

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