AIM:To conduct the relevance analysis of serum Dickkopf-1 (Dkk-1) and bone mineral density (BMD) in the different ages of female populations.METHODS: The women volunteers (n=100, 20~80 years old) were selected and divided into young group (20~39 years old), middle age group (40~59 years old) and elderly group (60~80 years old).The serum levels of Dkk-1 in the 3 groups of volunteers were detected by ELISA.In the middle age group, 25 people of 45~55 years old were selected and divided into postmenopausal group and premenopausal group to de-tect the serum level of Dkk-1 in the 2 groups of volunteers by ELISA.The BMD was measured by the method of dual energy X-ray absorptiometry.The differences of Dkk-1 expression levels among different ages of female populations, and the rele-vance with BMD were compared.RESULTS:With the increase in age, the serum Dkk-1 expression level increased ( P<0.05), and BMD were reduced (P<0.05).The blood level of Dkk-1 and BMD negatively correlated (P<0.05) in the 3 groups of volunteers.The serum levels of Dkk-1 and BMD had stronger negative correlation in postmenopausal women group than that in premenopausal women group.CONCLUSION:With the increase in age, the expression level of serum Dkk-1 increases and the BMD level decreases, which contribute to a risk of osteoporosis.In the same age range, the postmeno-pausal women express higher level of Dkk-1, and the decreased BMD is more obvious, which contribute to a greater risk of osteoporosis.The increased level of Dkk-1 also inhibits bone formation and promotes bone resorption.It may become a new target for preventing and treating osteoporosis.

Objective To investigate gait characteristics of both lower limbs in female patients before and after unilateral total knee arthroplasty (TKA). Methods Based on three-dimensional (3D) motion capture system and independent-sample t test, gait parameters of 10 female patients were compared in both lower limbs and compared with those of 10 healthy subjects before and after TKA. Results The preoperative stance phase, peak adduction angle, adduction-abduction range of motion (ROM) and peak flexion moment of the unoperated knee were significantly higher than those of the operated knee (P<0.05), while postoperative gait parameters were similar in both sides. Compared with the control group, the patients had significantly lower speed and stride length, longer double support time before TKA (P<0.05). Moreover, the operated knee demonstrated significantly lower peak extension and adduction angles, adduction-abduction ROM, peak flexion and abduction moments, higher peak adduction moment, and the unoperated knee revealed significantly lower peak extension angle, higher peak flexion and adduction moments than the control group before TKA (P<0.05). The greater differences of peak knee extension angles and adduction moments of both sides still existed in the two groups after TKA (P<0.05). Conclusions Unilateral TKA could ease pain and reduce gait deviations in both lower limbs of patients. However, there were still gait differences compared with the control group. Patients still suffered deficits in joint function, such as muscle strength and proprioception, and revealed pathological gait and posture. It’s advised that patients should enhance muscle strength of the operated limb, and take gait correction exercises. Female patients should also control walking speed to avoid increasing pressure on the knee after TKA.