2026 · Knee Surgery, Sports Traumatology, Arthroscopy
JLCA and coronal alignment progression: a longitudinal analysis of 10,841 knees
Rapid varus progression occurred in 34.0% (95% CI 32.8–35.1%), and rapid valgus progression in 25.7% (95% CI 21.2–30.7%).
Original Figure 2
Enlarge FigureOriginal standing long-leg radiographs illustrate alignment measurements, including the whole-leg axis and joint line.
Knee Surgery, Sports Traumatology, Arthroscopy (2026). DOI: 10.1002/ksa.70293 · Original Figure 2
Original Figure 3
Enlarge FigureThe original graph separates progression direction and rate by baseline alignment. Annual progression of at least 0.50° in the same direction occurred in 34.0% of the varus group and 25.7% of the valgus group.
Knee Surgery, Sports Traumatology, Arthroscopy (2026). DOI: 10.1002/ksa.70293 · Original Figure 3
Original Figure 9
Enlarge FigureROC curves for rapid varus and valgus progression, with AUCs of 0.823 and 0.756, respectively.
Knee Surgery, Sports Traumatology, Arthroscopy (2026). DOI: 10.1002/ksa.70293 · Original Figure 9
The research question
Participants and Methods
Main Findings
Implications for clinical and surgical practice
Limitations
Let's put it briefly.
Which clinical question does this address?
The study supports evaluating alignment progression alongside JLCA in OA follow-up. It does not directly prescribe target angles for HTO or TKA.
Keywords
- coronal alignment
- functional knee phenotypes
- hip‐knee‐ankle angle
- joint line convergence angle
- knee osteoarthritis
- alignment
- JLCA
- OA progression
Abstract · Original text
Kee Soo Kang, Sang Yoon Kim, Byung Sun Choi, Hyuk-Soo Han, Chong Bum Chang, Du Hyun Ro. Large joint line convergence angle is associated with accelerated coronal alignment progression in osteoarthritic knees: A longitudinal analysis of 10,841 knees. Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA. 2026. doi:10.1002/ksa.70293.
PURPOSE
Coronal knee alignment, determined by both joint line orientation and morphology of femur and tibia, alters with osteoarthritic progression, but its rate of change has not been systematically evaluated. This study aimed to categorise limbs according to the rate of hip-knee-ankle angle (HKAA) alteration and identify factors associated with accelerated alignment progression.
METHODS
10,841 limbs from a tertiary hospital were analysed. Alignment parameters and Kellgren-Lawrence (K-L) grades were measured on standing long-leg radiographs. Limbs were grouped by baseline HKAA as varus (HKAA ≤ 177°), neutral (177° < HKAA < 183°), or valgus (HKAA ≥ 183°). Accelerated and mild progression were defined as ≥ 0.50°/year and < 0.50°/year, respectively. Factors associated with accelerated coronal alignment progression were analysed using multivariable logistic regression.
RESULTS
Accelerated varus and valgus progression occurred in 34.0% (95% CI: 32.8%-35.1%) of the varus and 25.7% (21.2%-30.7%) of the valgus category, respectively. After adjustment for age, sex, and body mass index, greater baseline varus alignment, medial proximal tibial angle, and joint line convergence angle (JLCA) were associated with increased odds of accelerated varus progression by 4.9% (4.8%-5.0%), 10.8% (10.6%-10.9%), and 12.9% (12.7%-13.1%), respectively, in the varus category (n = 6519; AUC = 0.823). Higher K-L grade was associated with increased risk of accelerated varus progression compared with Grade 0 (I: 44.8% [44.5%-45.0%], II: 88.9% [88.6%-89.2%], III: 391.8% [346.1%-443.5%], and IV: 378.0% [305.0%-468.5%]; all p < 0.001). In the valgus category (n = 343), greater baseline HKAA and medially-opened JLCA increased the risk of accelerated valgus progression by 17.4% (3.6%-33.5%) and 19.4% (9.2%-28.8%), respectively (AUC = 0.756).
CONCLUSIONS
Approximately one-third of limbs with baseline HKAA ≤ 177° and about one-quarter of those with HKAA ≥ 183° exhibited ≥0.50° progression toward varus and valgus, respectively. Accelerated alignment change was associated with greater baseline HKAA, JLCA and higher baseline K-L grade, suggesting characteristics of this potential phenotype.
LEVEL OF EVIDENCE
Level III.
The original paper.
Large joint line convergence angle is associated with accelerated coronal alignment progression in osteoarthritic knees: A longitudinal analysis of 10,841 knees
Kee Soo Kang, Sang Yoon Kim, Byung Sun Choi, Hyuk-Soo Han, Chong Bum Chang, Du Hyun Ro
Knee Surgery, Sports Traumatology, Arthroscopy · 2026