2025 ISAKOS Biennial Congress ePoster
Preoperative Knee Cartilage Condition In The Patellofemoral Joint Results In Worse Clinical Outcome Scores 2 Years After Inverted V-Shaped High Tibial Osteotomy
Dai Sato, MD, PhD, Sapporo, Hokkaido JAPAN
Yeonseok Jo, MD JAPAN
Taku Ebata, MD, PhD, Sapporo JAPAN
Yoshiaki Hosokawa, MD, Sapporo, Hokkaido JAPAN
Koji Iwasaki, MD, PhD, Sapporo, Hokkaido JAPAN
Masatake Matsuoka, PhD, Sapporo JAPAN
Tomohiro Onodera, MD, PhD, Sapporo, Hokkaido JAPAN
Eiji Kondo, MD, PhD, Sapporo, Hokkaido JAPAN
Norimasa Iwasaki, MD, PhD, Sapporo, Hokkaido JAPAN
Hokkaido University, Sapporo, Hokkaido, JAPAN
FDA Status Cleared
Summary
The study highlights that preoperative knee cartilage condition in the PF joint, as assessed by WORMS, is significantly associated with postoperative clinical outcomes following iV-HTO.
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Abstract
Background
Inverted V-shaped high tibial osteotomy (iV-HTO) is a surgical intervention used to treat knee osteoarthritis (OA) in patients with varus knee alignment, even combined with patellofemoral (PF) joint OA. While iV-HTO has shown favorable outcomes, the impact of preoperative PF joint cartilage condition on postoperative results remains underexplored. This study aimed to assess the relationship between the preoperative cartilage condition of the PF joint, as evaluated by MRI using the Whole Organ Magnetic Resonance Imaging Score (WORMS), and clinical outcomes two years after iV-HTO.
Methods
The study retrospectively identified patients who underwent iV-HTO for knee OA between 2015 and 2022 by two senior orthopedic surgeons. A total of 48 knees from 39 patients were included after applying inclusion and exclusion criteria, such as the availability of preoperative MRI and a minimum of two years of follow-up. The study utilized WORMS to evaluate preoperative overall knee condition and assessed clinical outcomes using the Lysholm score and Knee Osteoarthritis and Injury Outcome Score (KOOS) both preoperatively and at the two-year follow-up. Radiographic parameters, including hip-knee angle (HKA), percent of mechanical axis (%MA), femorotibial angle (FTA), and medial proximal tibial angle (MPTA), were also measured. Statistical analysis was conducted using Pearson correlation and paired t-tests, with significance set at p = 0.05.
Results
The average age of participants was 55.1 years, with an average BMI of 28.0, and 15 of the 39 patients were male. The study found significant improvements in Lysholm and KOOS scores from preoperative status to two years post-surgery. Radiographic parameters also showed significant changes over the same period. Although there was no significant correlation between the overall WORMS score and the Lysholm score, a significant correlation was found between the WORMS cartilage subscale and the KOOS Symptoms and Stiffness subscale. Specifically, worse cartilage condition in the patella and trochlea correlated with poorer outcomes in multiple KOOS subscales, including Symptoms and Stiffness, Pain, Sports/Recreation, Quality of Life, and overall KOOS scores.
Discussion
The study highlights that preoperative knee cartilage condition in the PF joint, as assessed by WORMS, is significantly associated with postoperative clinical outcomes following iV-HTO. Higher WORMS cartilage scores, particularly in the patella and trochlea, were linked to worse clinical outcomes at the two-year follow-up. This finding suggests that the condition of the PF joint cartilage before surgery is an important factor in predicting the success of iV-HTO. Previous studies have demonstrated that lateral closed wedge high tibial osteotomies, including iV-HTO, are effective even in patients with PF OA, but the current study is the first to establish a direct relationship between preoperative PF joint cartilage condition and postoperative outcomes. This study underscores the importance of evaluating preoperative PF joint cartilage condition as it may predict postoperative outcomes following iV-HTO. Understanding this relationship can guide patient selection and preoperative planning to optimize surgical outcomes.