2025 ISAKOS Biennial Congress Paper
Achieving Sufficient Valgus Alignment is Essential to Ensure Low Residual Pain in Short to Mid-term Follow-up After High Tibial Osteotomy in K-L Grade 4 Osteoarthritis Patients
Byeong-Hun Jeon, MD, Seoul KOREA, REPUBLIC OF
Se-Han Jung, MD, Seoul KOREA, REPUBLIC OF
Min Jung, MD, PhD, Seoul KOREA, REPUBLIC OF
Kwangho Chung, MD, Seoul KOREA, REPUBLIC OF
Hyun-Soo Moon, MD, PhD, Seoul KOREA, REPUBLIC OF
Sung-Hwan Kim, MD, PhD, Seoul KOREA, REPUBLIC OF
Severance Hospital, Yonsei University College of Medicine, Seoul, Seoul, KOREA, REPUBLIC OF
FDA Status Cleared
Summary
High tibial osteotomy with sufficient valgus alignment (weight-bearing line ratio >62.2–67.3%) can yield comparable clinical outcomes in Kellgren-Lawrence grade 4 osteoarthritis patients as in those with lower-grade osteoarthritis.
Abstract
Background
Severe osteoarthritis has been identified as a risk factor for inferior outcomes following high tibial osteotomy (HTO).
Purpose
This study investigates the effectiveness of HTO in patients with advanced osteoarthritis, particularly those with Kellgren-Lawrence (KL) grade 4 (KL4). It aims to compare clinical outcomes based on osteoarthritis severity and the impact of postoperative alignment in each group.
Study design: Retrospective cohort study; level of evidence III.
Methods
A retrospective review was conducted on patients who underwent medial opening-wedge HTO from 2010 to 2022, with a follow-up period of 2 to 5 years. Patients were divided into two groups based on preoperative KL grades: non-KL4 and KL4. Extreme under-correction and over-correction cases were excluded. Clinical outcomes were compared using patient-reported outcome measures (PROs): pain visual analogue scale (VAS), Lysholm knee score, and Knee injury and Osteoarthritis Outcome score (KOOS) between the groups. Subgroup analyses were conducted whether outcomes differed based on postoperative weight-bearing line (WBL) ratio within each group.
Results
Out of total 324 patients, 141 were selected: 110 in the non-KL4 group and 31 in the KL4 group, with a mean follow-up of 37.5 months. Baseline demographics were similar between groups. The KL4 group had more severe preoperative conditions (larger defect size, more varus). However, both groups showed significant improvements in PROs (p<0.001), with no significant difference be-tween them. In the KL4 group, patients with a postoperative WBL ratio ≥62.5% showed better PROs (VAS: 17.1±19.1 vs. 33.9±18.3, p=0.032; KOOS-ADL: 78.7±9.9 vs. 69.3±13.8, p=0.041). In contrast, the non-KL4 group showed no PRO difference based on WBL ratio. In the KL4 group, final VAS was most correlated with WBL ratio (r=-0.545, p=0.002). a WBL ratio of 62.2–67.3% was the cut-off value to predict the achievement of low residual pain (VAS <18, median of KL4 group) in KL4 patients.
Conclusion
HTO can yield comparable clinical outcomes in KL4 osteoarthritis patients as in those with lower-grade osteoarthritis. However, achieving sufficient valgus alignment (WBL ratio >62.2–67.3%) is essential to minimize residual pain in the short to mid-term follow-up.