Clinical and Patient-Reported Outcomes of Medial Stabilized Versus Non-Medial Stabilized Prostheses in Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

J Arthroplasty. 2021 Feb;36(2):767-776.e2. doi: 10.1016/j.arth.2020.07.086. Epub 2020 Aug 8.


Background: The aim of this systematic review and meta-analysis was to compare the clinical and patient-reported outcome measures (PROMs) of medial stabilized total knee arthroplasty (TKA) with non-medial stabilized TKAs.

Methods: A systematic search of multiple databases was conducted in October 2019. A meta-analysis was conducted for the Knee Society Score (KSS), Knee Society Functional Score (KFS), range of motion (ROM), Oxford Knee Score (OKS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Forgotten Joint Score (FJS).

Results: A total of 857 articles yielded 21 studies eligible for inclusion with 13 studies used for quantitative analysis. The meta-analysis revealed that the medial stabilized group had a mean FJS that was 13.8 points higher than that of the non-medial stabilized TKA (mean difference [MD]: 13.83, P ≤ .0001, 95% confidence interval [CI]: 8.90-18.76, I2 = 0%) which was less than the minimal clinically important difference of 14. The medial stabilized group also demonstrated a statistically significant difference in the postoperative ROM (MD = 2.52, P = .05, 95% CI: -0.03 to 5.07, I2 = 85%) and OKS when compared with the non-medial stabilized group (MD = 1.25, P = .02, 95% CI: 0.17-2.33, I2 = 27%), but these were not clinically significant. There was no statistically or clinically significant difference in the KSS, KFS, and WOMAC scores.

Conclusion: Medial stabilized knee prostheses demonstrated no clinically significant differences for the ROM, OKS, WOMAC, KSS, and KFS. The FJS demonstrated the greatest MD and warrants further investigation. Future research is required using patient-reported outcome measures with a lower ceiling effect such as the FJS.

Keywords: Forgotten Joint Score (FJS); medial stabilized knee (MS); non–medial stabilized knee (NMS); patient-reported outcome measures (PROMs); range of motion (ROM); total knee arthroplasty.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Arthroplasty, Replacement, Knee*
  • Humans
  • Knee Joint / surgery
  • Knee Prosthesis*
  • Osteoarthritis, Knee* / surgery
  • Patient Reported Outcome Measures
  • Range of Motion, Articular