老年膝骨关节炎患者膝关节肌力与骨密度相关性分析

目的探讨老年膝骨关节炎(knee osteoarthritis,KOA)患者膝关节肌力与骨密度(bone mineral density,BMD)的相关关系。方法采用多关节等速力量测试与训练系统测试老年KOA患者膝关节肌力;采用双能X线骨密度仪检测老年KOA患者BMD,并分析两者之间的关系。结果 (1)老年KOA患者主患侧伸膝肌群峰力矩、相对峰力矩均显著低于对侧。(2)老年KOA患者双侧膝关节肌力部分指标与BMD相关,在等长等速模式下,伸膝肌群峰力矩与髋关节以及L1-L4 BMD呈正相关;屈膝肌群峰力矩与股骨颈、髋关节以及L1-L4 BMD呈正相关。(3)老年KOA患者主患侧膝关节肌力部分指标与BMD有一定相关性,在等速模式下,屈膝肌群峰力矩以及相对峰力矩与主患侧髋关节以及股骨颈BMD呈正相关;在等长等速模式下,伸膝以及屈膝肌群峰力矩与L1-L4 BMD呈正相关。结论老年KOA患者膝关节肌力与骨密度之间存在相关性。加强膝关节肌力锻炼,特别要加强主患侧屈膝肌群肌力锻炼,可能会提高髋关节、股骨颈以及腰椎BMD,从而预防骨质疏松。

The correlation between knee muscle strength and bone mineral density in elderly patients with knee osteoarthritis

Objective To study the correlation between knee muscle strength and bone mineral density (BMD) in elderly knee osteoarthritis (KOA) patients. Methods The knee muscle strength and BMD of elderly KOA patients were measured respectively by multi-joint isokinetic force test and training system and dual-energy X-ray bone densitometer. Then the relationship between them were analyzed. Results (1) The peak torque (PT) and PT/body weight (BW) of the extensor knee muscle on the main affected side of elderly KOA patients were significantly lower than those on the opposite side. (2) Some indexes of bilateral knee muscle strength in elderly KOA patients were correlated with BMD. In the isokinetic and constant speed mode, the PT of knee extension muscle was positively correlated with total hip and L1-L4 BMD. The PT of knee flexion muscle was positively correlated with femoral neck, total hip and L1-L4 BMD. (3) There was certain correlation between the muscle strength of the main affected knee joint side and BMD in elderly KOA patients. In the isokinetic mode, the PT and PT/BW of flexion muscle were positively correlated with hip and femoral neck BMD at the main affected side. In the isokinetic and constant speed mode, the PT of knee extension and flexion muscles was positively correlated with L1-L4 BMD. Conclusion There were correlations between knee muscle strength and bone mineral density in elderly KOA patients. Exercises that strengthen knee muscle strength, especially knee muscle of the main affected side, may improve hip, femoral neck and lumbar spine BMD, therefore preventing osteoporosis.