Complications and functional outcomes after reconstruction of the proximal humerus with allograft-prosthetic composite: a systematic review of the literature.

Background: Allograft prosthetic composite (APC) reconstruction is performed after resection of proximal humerus tumors or failure of arthroplasty implants. There is limited literature on the postoperative outcomes of this technique. We sought to assess implant survival, failure rates, and postoperative functional outcomes after APC reconstruction of the proximal humerus.
Methods: A systematic review of the PubMed and Embase databases was conducted. The study was registered on PROSPERO (ID: 448,663). The Strengthening of the Reporting of Observational Studies in Epidemiology checklist was used for quality assessment. Implant failure was determined using the Henderson classification for biological reconstruction. Functional outcome was primarily assessed using the Musculoskeletal Tumor Society score at last follow-up.
Results: Twenty-five studies with a total of 488 patients were included. Mean follow-up in reporting studies ranged from 2.5 to 10 years. Five-year revision-free survival for implants ranged from 41% to 92%. Overall implant failure rate ranged from 9% to 54%, and reoperation rate ranged from 0% to 55%. Graft host nonunion (type 2) was the most common mode of failure, with rates ranging from 0% to 75%. The mean Musculoskeletal Tumor Society scores at last follow-up ranged from 57% to 90% across studies. A trend towards better functional outcomes was seen in patients having an APC with a reverse total shoulder arthroplasty (rTSA) compared with those with hemiarthroplasty.
Conclusions: APCs show promise in proximal shoulder reconstruction, with heterogeneous functional outcomes that are noninferior to other reconstruction techniques. Graft host nonunion is a common mode of failure and remains a concern in this type of prosthesis. Future studies should compare rTSA-APCs and rTSA endoprostheses while controlling for potential confounders.
(Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)