Ultrasonographic Evaluation of Distal Femoral Cartilage Thickness in Patients with Lower Extremity Lymphedema

<b><i>Background:</i></b> Cartilage thickness has been evaluated in many diseases, and its relationship with osteoarthritis has been investigated. However, the effect of lower extremity lymphedema on knee joint cartilage has not been well investigated. This study aimed to evaluate the distal femoral cartilage thickness ultrasonographically in patients with unilateral lower extremity lymphedema and to investigate its relationship with clinical features. <b><i>Methods and Results:</i></b> This cross-sectional study included 27 patients (mean age: 49.56 ± 12.06 years; 92.6% female) with unilateral lower extremity lymphedema. Distal femoral cartilage thickness of both knees was measured at the medial condyle, lateral condyle, and intercondylar notch by using ultrasound. Functional status and quality of life were assessed with the Lower Extremity Functional Scale and Lymphedema Quality of Life Questionnaire, respectively. The mean intercondylar notch cartilage was significantly thinner on the lymphedema side compared to the contralateral side (2.03 ± 0.41 mm vs. 2.24 ± 0.58 mm, <i>p</i> < 0.05). Although the medial (1.96 ± 0.36 mm vs. 2.04 ± 0.42 mm) and lateral (1.90 ± 0.37 mm vs. 2.03 ± 0.41 mm) condyles were also thinner on the affected side, they were not statistically significant (<i>p</i> > 0.05). No significant correlations were identified between distal femoral cartilage thickness at the intercondylar notch and clinical features, functionality, and quality of life (<i>p</i> > 0.05). <b><i>Conclusions:</i></b> This study showed that distal femoral cartilage thickness, particularly at the intercondylar notch, is thinner in the affected limbs of patients with unilateral lower extremity lymphedema. These findings suggest that knee joint cartilage integrity may be affected in patients with lower extremity lymphedema and that ultrasonographic evaluation may be useful in this regard.