Wearable ultrasound patches can revolutionize traditional ultrasound medical applications by offering the capability for hands-free, long-term, and continuous diagnostics and treatment. However, current flexible ultrasound transducers have no control over the curvature and face challenges of low throughput and limited design space due to manual manufacturing. Here, we show flexible ultrasound transducers with flex-to-rigid statically adjustable curvature, which are fabricated using a hybrid wafer-scale microfabrication. The transducer exhibits excellent electrical and acoustic performances at a center frequency of 1.5 MHz and 3.4 MHz in immersion. To effectively utilize these characteristics, ultrasound was administered to the spleen of mice with arthritis. This treatment was conducted periodically over a two-week duration to evaluate its efficacy in alleviating symptoms of arthritis. The efficacy of the treatment was verified through continuous measurements of ankle swelling and gait analysis. We demonstrate the potential of continuous therapeutic interventions using a wearable ultrasound patch for anti-inflammatory treatment.