Does changes in unicompartmental knee arthroplasty practice pattern influence reasons for revision?

Area of Science:

• Orthopedic Surgery
• Arthroplasty Research
• Biostatistics in Medical Research

Background:

• Knee arthroplasty, including unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA), is a common procedure for osteoarthritis.
• Understanding revision indications and trends is crucial for improving long-term outcomes and surgical practices.
• Previous studies have established general revision patterns, but recent changes require updated analysis.

Purpose of the Study:

• To delineate the revision indication patterns for UKA and TKA over a 20-year period (1997-2017).
• To identify and analyze changes in UKA revision indications over the last decade.
• To explore potential associations between observed changes and evolving surgical practices.

Main Methods:

• Analysis of primary knee arthroplasty surgeries and revisions from the Danish Knee Arthroplasty Register (1997-2017).
• Exclusion of complex surgeries; linkage with national registers for patient data (comorbidity, mortality, emigration).
• Propensity score matching (4:1 ratio) for TKAs to UKAs; competing risk Cox proportional hazard regression with shared frailty for revision risk comparison.

Main Results:

• Aseptic loosening was the leading revision cause for both UKA (26.7%) and TKA (29.5%).
• Pain and disease progression constituted 54.6% of remaining UKA revisions; infections and instability 56.1% of TKA revisions.
• Revision incidence for loosening or pain decreased significantly in the last decade, associated with cementless fixation and high UKA usage.

Conclusions:

• Overall revision patterns for UKA and TKA over 20 years align with previously published data.
• Significant shifts in UKA revision patterns were observed in the last decade.
• Current surgical practices appear to reduce the likelihood of UKA revision due to pain or loosening.