No difference in functional outcomes, quality of life and survivorship between metal-backed and all-polyethylene tibial components in unicompartmental knee arthroplasty: a 10-year follow-up study

Abstract

PurposeThe purpose of this study was to compare functional outcomes, quality of life and survivorship at a minimum of 10 years postoperatively, between MB and AP tibial components in fixed‐bearing UKAs. MethodsA retrospective cohort study of 146 Query ID="Q3" Text="Author names: Please confirm if the author names are presented accurately and in the correct sequence (Lo Ngai Nung, Yeo Seng Jin). Also, kindly confirm the details in the metadata are correct." UKAs performed between 2004 and 2007 by a single fellowship‐trained arthroplasty surgeon was carried out. 27 UKAs received MB tibial components and 119 UKAs received AP tibial components. The cohort was followed up prospectively for 10 years. Functional outcomes were compared using the Knee Society Functional Score (KSFS), Knee Society Knee Score (KSKS) and Oxford Knee Score (OKS). Quality of life measures were obtained from the Physical Component Summary (PCS) and Mental Component Summary (MCS), derived from the Short Form 36 Health Survey (SF‐36). Propensity score matching was performed in a 1:3 ratio of MB versus AP tibial components to account for possible confounding variables. Thereafter, outcomes between the two groups were compared. The proportion of patients who had attained the minimum clinically important difference (MCID) for the abovementioned scores was recorded as well. ResultsAfter propensity score matching, there were 28 UKAs with MB tibial components and 76 UKAs with AP tibial components. There was no significant difference between the two groups in functional outcomes (KSFS, KSKS and OKS), quality of life (PCS and MCS) and survivorship (92.3% vs 91.1%, respectively) at a minimum of 10 years postoperatively. However, a significantly higher proportion of patients in the group with AP tibial components attained the MCID for PCS at 10 years postoperatively, compared to those with MB tibial components (p = 0.031). ConclusionIn conclusion, there were no significant differences in functional outcomes measures, quality of life and survivorship between MP and AP tibial components at a minimum of 10 years postoperatively. Level of evidenceIII.

First Italian Experience with the Oxinium Metal-Backed Fixed-Bearing Medial Journey II Unicompartmental Knee System: Promising Short-Term Outcomes of 145 Cases

“…As regards the FJS-12, we compared the values collected at 12 and 24 months ( p = 0.401). Our data are comparable to those of other mUKA studies and better in some cases [ 57 , 58 , 59 , 60 , 61 ]. The mean satisfaction, rated from 1 to 10, was 9.32 ± 0.74.…”

Metal-backed or all-poly tibial components: which are better for medial unicompartmental knee arthroplasty? A propensity-score-matching retrospective study at the 5-year follow-up

“…Another study found better KSSs and KOOSs and lower pain in MB-UKA than in AP-UKA patients at a follow-up of more than 10 years as well as no significant differences in knee range of motion [ 65 ]. Lee et al, employing PSM, did not report any statistically significant differences between MB-UKA and AP-UKA patients in terms of outcomes, quality of life, or 10-year implant survival [ 27 ].…”

“…Data analysis was performed using Microsoft Excel (2019) in conjunction with the XLSTAT resource pack (XLSTAT Premium, Addinsoft, New York, NY, USA). A propensity-score-matching (PSM) analysis was employed to minimize variations in known covariates between the cohorts [ 49 ], since several retrospective arthroplasty studies have used this type of analysis to minimize selection bias [ 8 , 27 , 50 – 57 ]. The two patient groups were matched one-to-one by an optimal matching algorithm [ 58 ].…”

Image‐based robotic‐arm assisted unicompartmental knee arthroplasty provides high survival and good‐to‐excellent clinical outcomes at minimum 10 years follow‐up

“…When considering specifically conventional medial fixed‐bearing implants, literature has reported survivorship rates ranging from 89.5% to 96.0% at 10 years [15, 28]. A prospective, comparative study between all‐polyethylene versus metal‐backed tibial components, reported a survivorship of 92.3% and 91.1%, respectively [16]. The main reason for UKA revision reported by Lee et al was progression of OA, regardless of bearing design.…”