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.