A retrospective review of revision proximal humeral allograft-prosthetic composite procedures: an analysis of proximal humeral bone stock restoration

Abstract

Background: Allograft-prosthetic composite (APC) reconstruction of the proximal humerus is a technique for reconstruction of large bone deficits, provides improvement in pain and function, and is thought to restore bone if revision surgery is needed. The purpose of this study was to evaluate the ability of proximal humeral APCs to restore usable bone at the time of revision surgery.

Methods: Two institutional electronic medical records were reviewed to evaluate proximal humeral APC procedures performed between 1970 and 2018. We identified 115 cases, of which 14 underwent revision for aseptic causes. The indications for revision included nonunion (n = 7), glenohumeral instability (n = 5), and allograft fracture (n = 2). Three categories were used to classify the amount of usable allograft retained at revision surgery: type A, complete allograft retention; type B, partial retention; and type C, no retention.

Results: A total of 14 patients (6 male and 8 female patients) underwent revision of the APC reconstruction at a mean of 22.8 months. At revision, allograft retention was classified as type A in 6 shoulders, type B in 3, and type C in 5. Type A cases were associated with nonunion with a well-fixed stem, type B cases were associated with instability and were converted from a hemiarthroplasty to a reverse total shoulder arthroplasty, and type C cases were associated with an allograft fracture or nonunion with a loose humeral component.

Conclusion: A substantial number of revisions of proximal humeral APC reconstructions maintain a portion of the allograft bone (64.3%). This study supports the ongoing use of the APC reconstruction technique for large bone deficits.

Keywords: APC; Shoulder arthroplasty; allograft; allograft-prosthetic composite; reconstruction; revision.