The Predictive Value of Ultrasonographic Quadriceps Muscle Parameters for Genicular Nerve Block Outcomes in Knee Osteoarthritis

The Role of Quadriceps Muscle Architecture Parameters in Predicting the Success of Genicular Nerve Block in Patients With Chronic Knee Osteoarthritis Pain

The goal of this observational study is to learn whether thigh muscle structure can help predict pain relief after a genicular nerve block in people with knee osteoarthritis. A genicular nerve block is an injection used to reduce pain signals from the knee.

The main questions are:

• Are muscle thickness, fiber length, and fiber angle linked to pain relief after the procedure?
• Are these muscle measurements linked to changes in physical function and quality of life?

Participants are adults aged 50 to 80 with long-term pain from osteoarthritis in one knee. They are already scheduled to receive a genicular nerve block as part of their regular medical care. The study does not assign participants to receive this procedure.

Before the procedure, researchers will use ultrasound to measure the vastus lateralis muscle in the thigh. Participants will also answer questions about pain, daily function, and quality of life. Researchers will repeat these assessments after 1 hour, 3 weeks, and 3 months. Pain relief will be considered successful when pain is at least half as severe as it was before the procedure.

Inclusion Criteria:

• Age between 50 and 80 years
• Unilateral symptomatic knee osteoarthritis
• Chronic knee pain for at least 3 months
• Clinical and radiographic confirmation of knee osteoarthritis
• Kellgren-Lawrence grade 3 or 4 knee osteoarthritis
• Inadequate clinical response despite analgesic therapy and physical therapy
• Clinical indication for genicular nerve block

Exclusion Criteria:

• History of surgery involving the knee region
• Bilateral symptomatic knee osteoarthritis
• Intra-articular knee injection within the previous 3 months
• Systemic disease that could affect study assessments
• Systemic or local infection
• Coagulation disorder
• Failure to provide written informed consent