This study will observe patients with lower limb varicose veins who also have knee pain. Many patients with varicose veins experience swelling, heaviness, or aching in the legs, and some also report pain in or around the knee. Previous studies suggest that venous reflux and poor circulation may increase discomfort in the knee, especially when knee osteoarthritis is present.

The purpose of this study is to evaluate whether treatment of varicose veins with standard endovenous procedures can improve knee pain and function. Participants will undergo standard vein treatment as part of their clinical care. We will follow them for changes in knee pain, quality of life, and leg symptoms over time.

This study does not assign patients to experimental interventions. Instead, it collects information before and after treatment to better understand the relationship between varicose veins and knee pain relief. Findings from this study may help doctors identify which patients are most likely to benefit from venous treatment in terms of both leg and knee symptoms.

Inclusion Criteria:

Adults aged ≥18 years. Clinical diagnosis of lower limb varicose veins with documented venous reflux on duplex ultrasound (CEAP C2-C4).

Presence of knee pain lasting ≥4 weeks prior to enrollment, confirmed by patient-reported VAS/NRS ≥3 at baseline.

Planned to undergo standard endovenous treatment (radiofrequency ablation, endovenous laser ablation, or equivalent).

Ability to provide informed consent and complete study questionnaires.

Exclusion Criteria:

Prior surgery or endovenous ablation for varicose veins in the same limb. History of inflammatory arthritis (e.g., rheumatoid arthritis, gout) or other systemic rheumatologic disease.

Recent acute knee injury (ligament, meniscus, fracture) within 6 months. Prior knee replacement or major knee surgery. Recent intra-articular injection or arthroscopy (<3 months). Known deep vein thrombosis or history of pulmonary embolism within the past 6 months.

Severe peripheral arterial disease (ABI <0.8). Pregnancy or breastfeeding. Inability to comply with follow-up schedule or complete questionnaires.

This study will include adult patients with clinically significant lower limb varicose veins (CEAP C2-C4) who also report knee pain. Participants are recruited from vascular surgery outpatient clinics and will undergo standard endovenous treatment as part of their clinical care. The study will observe changes in knee pain, function, and venous symptoms before and after treatment. Patients with advanced joint disease, systemic inflammatory disorders, or recent knee surgery are excluded to minimize confounding factors.

Plan Description: Individual participant data (IPD) will not be shared because the study is observational, single-center, and involves limited sample size. Data will be used only for the purpose of this research project and protected according to institutional regulations.