2025 ISAKOS Congress in Munich, Germany

2025 ISAKOS Biennial Congress ePoster

 

Preservation of Pre-Arthritic Coronal Knee Phenotype and Pre-Arthritic Coronal Alignment Yielded Improved Kujala Scores Following Ligament-Guided Medial Unicompartmental Knee Arthroplasty

Roderick J.M. Vossen, MD, New York, NY UNITED STATES
Joost Burger, MD, Berlin GERMANY
Gaby Victoria Ten Noever De Brauw, Bsc, Amsterdam NETHERLANDS
Tarik Bayoumi, MD, Amsterdam NETHERLANDS
Jake Fiore, Bsc, New York UNITED STATES
Lindsey Ruderman, BA, New York UNITED STATES
Hendrik Aernout Zuiderbaan, MD PhD, Velsen NETHERLANDS
Andrew D. Pearle, MD, New York, NY UNITED STATES

Hospital for Special Surgery, New York, NY, UNITED STATES

FDA Status Cleared

Summary

preservation of CPAK phenotype and preservation of prearthritic coronal alignment yielded a significantly higher Kujala score. The ligament-guided medial UKA provides equal outcomes for all observed phenotypes and sagittal-tibial-wear patterns in medial compartment OA as long as preoperative CPAK phenotype is preserved postoperatively.

ePosters will be available shortly before Congress

Abstract

Purpose

There is a lack of literature evaluating outcomes of the ligament-guided approach in medial unicompartmental knee arthroplasty (UKA). An improved comprehension of the distribution of coronal plane alignment of the knee (CPAK) phenotypes and sagittal-tibial-wear patterns and their associations with patient-reported outcome measures (PROMs) and implant survivorship could provide insights into its further application in daily practice.

Methods

A registry was reviewed for patients with a minimal two-year follow-up who underwent robotic-assisted, ligament-guided, medial UKA between 2008-2016. Survivorship and postoperative PROMs were collected. CPAK phenotypes and sagittal-tibial-wear patterns were determined. Survivorship, Knee Injury and Osteoarthritis Outcome Score (KOOS), Kujala and patient satisfaction were compared between phenotypes and sagittal-tibial-wear patterns.

Results

A total of 618 knees were included at a mean follow-up of 4.1 [2.0–9.6] years. Four-year conversion to TKA survival rate was 98.9% [98.4%-99.3%] and 94.3% [93.3%-95.3%] for all-cause revision. Patients with preservation of CPAK phenotype (84.5±14.9, 81.8±15.5; p = 0.033) and restoration of prearthritic coronal alignment (84.1±14.9, 81.7±15.9, p = 0.045) had a significantly higher Kujala score. No other significant differences in survivorship or PROMs were observed between phenotypes or sagittal-tibial-wear patterns. Additionally, no difference in survival rates was observed between preserved or altered phenotypes.

Conclusion

This study demonstrated that preservation of CPAK phenotype and preservation of prearthritic coronal alignment yielded a significantly higher Kujala score. No other significant differences in PROMs or implant survivorship were observed, suggesting that robotic-assisted, ligament-guided medial UKA provides equal outcomes for all observed phenotypes and sagittal-tibial-wear patterns in medial compartment OA as long as preoperative CPAK phenotype is preserved postoperatively.