The purpose of this study is to investigate the relationship between walking ability, pain, and psychological aspects in the early period after knee replacement surgery, with a focus on nighttime sleep.
The subjects of this study were 20 patients who had undergone arthroplasty for osteoarthritis of the knee. The subjects were surveyed about pain and range of motion in the operated knee joint, straight walking at maximum speed (gait speed, cadence), weight-bearing on the operated limb in the standing position corrected for body weight (WB), total sleep time at night (TST), questionnaires (PCS, HADS), and the number of days from surgery to cane-walking independence (DSC). Nighttime sleep was measured for five days from days 2 to 7 after surgery, and other items were measured one week after surgery. Correlations between each factor were examined for statistical analysis.
A positive correlation was found between PCS and knee joint pain (at rest: rs = 0.43, while walking: rs = 0.40). We also found a positive correlation between PCS and HADS (rs = 0.49). A positive correlation was found between TST and knee joint pain (at rest: rs = 0.55, while walking: rs = 0.42). A negative correlation was found between TST and cadence (r = -0.49). Positive correlations were found between gait speed (rs = 0.61) and cadence (rs = 0.50) and knee flexion range of motion. A negative correlation was found between walking speed and DSC (rs = -0.59). A positive correlation was found between WB and walking speed (r = 0.54). A negative correlation was found between WB and knee joint pain at rest (rs = -0.38). A positive correlation was found between WB and stride length (operative side: r = 0.61, nonoperative side: r = 0.62).
It was suggested that the stronger the catastrophic thinking, the greater the tendency for anxiety and depression, and the more pain the patient may experience. In addition, the greater the pain, the longer the patient spent less time moving during the night, which may have delayed improvement in cadence and knee joint range of motion. It was suggested that putting more weight on the operative leg in the early postoperative period may lead to a greater swing of the leg on both the operative and nonoperative side during gait at maximum speed and shortens the number of days until cane walking independence.
Nighttime sleep duration affects subjective perception of pain, and increased sleep duration may lead to improved ambulation. Medical staff performing postoperative rehabilitation should monitor the patient's sleep status and actively load on the operated limb to support the patient achieve better knee joint function and early independent gait.
postoperative acute pain
psychological aspects
