Measurement of physical activity and prevention of physical inactivity/sedentary behaviors in patients with septic knee arthritis before and after hospital discharge: A case report

Background Patients with septic knee arthritis tend to have prolonged pain, which may lead to a decrease in physical activity (PA). Pain catastrophizing, which is associated with chronic pain, is known to be a limiting factor for PA. An objective measurement of PA in patients with septic knee arthritis has not been reported. Here we describe the accelerometry‐based measurement of the PA of a patient with septic knee arthritis before and after discharge, and we report the ability of follow‐up outpatient physical therapy to increase PA. Methods A 70‐year‐old Japanese woman admitted to the hospital with a diagnosis of left septic knee arthritis presented with prolonged pain and pain catastrophizing in the left knee. We investigated her pre‐ and post‐discharge PA by using an accelerometer. We also investigated her physical function, pain, and pain catastrophizing as a possible influence on PA. Follow‐up outpatient physical therapy (consisting of PA feedback, counseling, and reassurance) was performed to improve the patient's physical function and increase her PA. Results The patient's PA indicated general inactivity from pre‐discharge to 1 month post‐discharge, especially immediately post‐discharge (sedentary behavior [SB]: 540–571.3 min/daytime, light‐intensity PA: 145.8–177.8 min/daytime). The follow‐up outpatient physical therapy was effective in increasing her physical function and PA (a 31‐min decrease in SB, a 32‐min increase in light‐intensity PA) but was not effective in reducing her pain or pain catastrophizing. Discussion Contrary to the general trend, this patient showed a decrease in PA after hospital discharge compared to PA during hospitalization. Follow‐up outpatient physical therapy had the effect of increasing the patient's PA, which was decreased immediately post‐discharge.