Retrospective Cohort Study
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Apr 18, 2023; 14(4): 218-230
Published online Apr 18, 2023. doi: 10.5312/wjo.v14.i4.218
Clinical outcomes of cemented distal femur replacements with all-polyethylene tibial components for oncologic indications
Alexander B Christ, Brian C Chung, Matthew Urness, Lucas W Mayer, Brandon S Gettleman, Nathanael D Heckmann, Lawrence R Menendez
Alexander B Christ, Brian C Chung, Matthew Urness, Lucas W Mayer, Nathanael D Heckmann, Lawrence R Menendez, Department of Orthopedic Surgery, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, United States
Brandon S Gettleman, University of South Carolina School of Medicine, Columbia, SC 29209, United States
Author contributions: Christ AB, Menendez LR, and Heckmann ND generated the idea, provided guidance throughout, were heavily involved in copy-editing, and oversaw execution of the project; Chung BC, Urness M, Mayer L, and Gettleman BS were responsible for data collection, literature review, statistical analysis, and drafting the manuscript; All authors listed read and approved the final manuscript.
Institutional review board statement: Proposal #HS-20-00396 indicates that this study is determined to be IRB exempt.
Informed consent statement: The study is IRB-exempt at our institution because we did not employ the use of humans and the use of their protected health information for this study was deemed minimal risk. Thus, an Informed Consent form is not applicable for this study.
Conflict-of-interest statement: One of the authors (N.D.H.) is a paid consultant for Intellijoint Surgical and MicroPort Orthopedics, has stock options from Intellijoint Surgical, and is a committee member of AAOS and AJRR. One of the authors (L.R.M.) is a paid consultant for Onkos Surgical and receives IP royalties from TeDan Surgical. Each author certifies that he has no commercial associations that might pose a conflict of interest in connection with the submitted article. One of the authors (A.B.C) is a board member for AAOS, Musculoskeletal Tumor Society, Orthopaedic Society. (A.B.C) is also a paid consultant for Smith and Nephew, Intellijoint Surgical, and Enovis.
Data sharing statement: No additional data are available.
STROBE statement: The authors have read the STROBE Statement – checklist of items, and the manuscript was prepared and revised according to the STROBE Statement – checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Alexander B Christ, MD, Doctor, Department of Orthopedic Surgery, Keck School of Medicine of University of Southern California, 1500 San Pablo Street, Los Angeles, CA 90033, United States. alexander.b.christ@gmail.com
Received: January 13, 2023
Peer-review started: January 13, 2023
First decision: February 2, 2023
Revised: February 10, 2023
Accepted: April 4, 2023
Article in press: April 4, 2023
Published online: April 18, 2023
Abstract
BACKGROUND

Endoprosthetic distal femoral replacement (DFR) is a well-established salvage procedure following resection of malignant tumors within the distal femur. Use of an all-polyethylene tibial (APT) component is cost-effective and avoids failure due to locking-mechanism issues and backside wear, but limits modularity and the option for late liner exchange. Due to a paucity of literature we sought to answer three questions: (1) What are the most common modes of implant failure for patients undergoing cemented DFR with APT for oncologic indications? (2) What is the survivorship, rate of all-cause reoperation, and rate of revision for aseptic loosening of these implants? And (3) Is there a difference in implant survivorship or patient demographics between cemented DFRs with APT performed as a primary reconstruction vs those performed as a revision procedure?

AIM

To assess outcomes of cemented DFRs with APT components used for oncologic indications.

METHODS

After Institutional Review Board approval, a retrospective review of consecutive patients who underwent DFR between December 2000 to September 2020 was performed using a single-institutional database. Inclusion criteria consisted of all patients who underwent DFR with a GMRS® (Global Modular Replacement System, Stryker, Kalamazoo, MI, United States) cemented distal femoral endoprosthesis and APT component for an oncologic indication. Patients undergoing DFR for non-oncologic indications and patients with metal-backed tibial components were excluded. Implant failure was recorded using Henderson's classification and survivorship was reported using a competing risks analysis.

RESULTS

55 DFRs (55 patients) with an average age of 50.9 ± 20.7 years and average body mass index of 29.7 ± 8.3 kg/m2 were followed for 38.8 ± 54.9 mo (range 0.2-208.4). Of these, 60.0% were female and 52.7% were white. The majority of DFRs with APT in this cohort were indicated for oncologic diagnoses of osteogenic sarcoma (n = 22, 40.0%), giant cell tumor (n = 9, 16.4%), and metastatic carcinoma (n = 8, 14.6%). DFR with APT implantation was performed as a primary procedure in 29 patients (52.7%) and a revision procedure in 26 patients (47.3%). Overall, twenty patients (36.4%) experienced a postoperative complication requiring reoperation. The primary modes of implant failure included Henderson Type 1 (soft tissue failure, n = 6, 10.9%), Type 2 (aseptic loosening, n = 5, 9.1%), and Type 4 (infection, n = 6, 10.9%). There were no significant differences in patient demographics or rates of postoperative complications between the primary procedure and revision procedure subgroups. In total, 12 patients (21.8%) required a revision while 20 patients (36.4%) required a reoperation, resulting in three-year cumulative incidences of 24.0% (95%CI 9.9%-41.4%) and 47.2% (95%CI 27.5%-64.5%), respectively.

CONCLUSION

This study demonstrates modest short-term survivorship following cemented DFR with APT components for oncologic indications. Soft tissue failure and endoprosthetic infection were the most common postoperative complications in our cohort.

Keywords: Distal femoral replacement, Modular, Revision, Dislocation, Oncologic

Core Tip: The current study demonstrates modest short-term survivorship following cemented distal femoral replacement with all-polyethylene tibial components for oncologic indications. Approximately one third of patients experienced a postoperative complication. The most common modes of implant failure were soft tissue failure and endoprosthetic infection.