Factors Related to Standing Balance in Patients With Knee Osteoarthritis

OBJECTIVE: To assess factors related to standing balance in patients with knee osteoarthritis (OA). METHODS: In total, 37 female patients with painful knee OA were included. Pain, knee alignment, and Kellgren and Lawrence grade were evaluated accordingly. Static standing balance was measured with a force-platform system under two different conditions: static standing with eyes open (EO) and eyes closed (EC) for 30 seconds. The mean speed (mm/s) of movement of the center of pressure in the anteroposterior (AP) and mediolateral directions and the mean velocity moment (mm2/s) were analyzed for assessment of static balance. RESULTS: In the univariate regression analysis, age and knee alignment showed statistically significant relationships with the mean speed in the AP directions with EO. In the multiple linear regression model, age and knee alignment were positively associated and disease severity was negatively associated with mean speed in the AP directions with EO. However, the variables for EC static measurements were not significantly correlated with age, pain, knee alignment, or radiographic severity (p>0.05). CONCLUSION: These findings show that the worse balance was associated with advanced age, less varus knee malalignment, and mild radiographic changes. Pain was not associated with standing balance.

Postpartum Sacral Stress Fracture Mimicking Lumbar Radiculopathy in a Patient With Pregnancy-Associated Osteoporosis

Postpartum sacral fracture is relatively rare, and its diagnosis is often delayed. We herein report such a case of a 28-year-old patient who presented with an insidious-onset lower back pain, left buttock pain, and radicular symptoms mimicking lumbar radiculopathy. Laboratory tests showed a decreased 25-hydroxy vitamin D level, and the bone mineral densitometry of both femurs was below the expected range. Plain radiographs of the lumbar spine and pelvis showed no definite abnormality, but lumbosacral spinal magnetic resonance imaging identified a left sacral fracture. Symptoms were alleviated with rest and oral analgesic treatment.