Knee-extension strength, postural control and function are related to fracture type and thigh edema in patients with hip fracture.

Background: Post-surgery thigh edema, loss of knee-extension strength, and reduced physical performance are common following a hip fracture. It is not known if knee-extension strength and physical performance are related to the edema and fracture type. The aim of this study was to examine the influence of fracture type and post-surgery edema on physical performances in patients with hip fracture.

Methods: Fifteen women and five men admitted from their own home to an acute orthopedic hip fracture unit were examined. Ten had cervical and ten had intertrochanteric fractures. Correlations between fracture type and thigh edema in the fractured limb (% non-fractured) to physical performances of basic mobility, postural control (sway), and isometric knee-extension strength were examined. All measures, except those of basic mobility, were conducted at the time of discharge, 8.5 days post-surgery.

Findings: Patients with intertrochanteric fractures had greater edema (111% non-fractured limb) compared with cervical fractures (104% non-fractured, P<0.001). Thigh edema was significantly correlated to lower scores of basic mobility (r=-0.61, P=0.004), reduced postural control (r=0.67, P=0.001), and fractured limb knee-extension strength deficit ([% non-fractured], r=-0.77, P<0.001), explaining between 32% and 59% of the variance (r(2)) in performances.

Interpretation: Our results indicate that fracture type and the corresponding thigh edema are important factors influencing physical performances after hip fracture. These findings have important implications for rehabilitation programs and for further research in patients with hip fracture.