Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2019 Aug;34(8):1617-1625.
doi: 10.1016/j.arth.2019.04.004. Epub 2019 Apr 8.

Unicondylar Knee Arthroplasty Has Fewer Complications but Higher Revision Rates Than Total Knee Arthroplasty in a Study of Large United States Databases

Erik N Hansen  1 , Kevin L Ong  2 , Edmund Lau  3 , Steven M Kurtz  2 , Jess H Lonner  4
Affiliations

Unicondylar Knee Arthroplasty Has Fewer Complications but Higher Revision Rates Than Total Knee Arthroplasty in a Study of Large United States Databases

Erik N Hansen et al. J Arthroplasty. 2019 Aug.

Abstract

Background: Unicondylar knee arthroplasty (UKA) has superior functional outcomes compared to total knee arthroplasty (TKA) with good mid-term and long-term survival data from high-volume institutions. We sought to quantify the risk of complications, re-operation/revision, hospital re-admission for any reason, and mortality of knee arthroplasty patients in the US patient population using 2 large databases.

Methods: UKA and TKA patients who were identified in the 2002-2011, 5% sample of Medicare data and 2004-2012 (June) MarketScan Commercial and Medicare Supplemental Databases were followed to evaluate the risk of complications, hospital re-admission for any reason, and mortality within 90 days of surgery. Survival probability defined by re-operation was calculated using the Kaplan-Meier method at 0.5, 2, 5, 7, and up to 10 years post-operatively.

Results: Compared to UKA, complication rates for TKA patients were significantly higher, including wound complication, pulmonary embolism, stiffness, peri-prosthetic joint infection, myocardial infarction, re-admission, and death. Age was found to be a significant risk factor (P < .05) for all complications in the Medicare cohort, except stiffness (P = .839), and all complications in the MarketScan cohort, except re-admission (P = .418), whereas gender had a variable effect on complications based on age. Survivorship of UKA was lower than TKA at all time points. Additionally, younger age adversely affected implant survival. By 7 years post-surgery, UKA survivorship in the Medicare and MarketScan cohorts was 80.9% and 74.4%, respectively. In contrast, TKA survivorship for the same cohorts was 95.7% and 91.9% by the same time point.

Conclusion: Patients undergoing UKA have fewer post-operative complications and re-admissions than those undergoing TKA. However, patients undergoing UKA have a higher rate of re-operation and revision at up to 10 years of follow-up. It appears that age, as well as surgeon and hospital volume significantly impacts implant survivorship while gender does not have a relation.

Level of evidence: Level III.

Keywords: UKA; complications; re-operation; revision; unicompartmental; unicondylar knee arthroplasty.

PubMed Disclaimer