[Study on distribution features of tender points in patients with knee osteoarthritis by cluster analysis]

To observe the distribution features of tender points in knee of patients with knee osteoarthritis in order to provide evidences for the treatment and diagnosis.

From November 2011 to December 2012,86 patients with knee osteoarthritis were recruited, including 21 males and 65 females, ranging in age from 45 to 85 years old, with an average of (59.98 +/- 8.23) years old. The course of disease ranged from 3 months to 15 years. The tender points and its distributions were determined by finger press carefully on their knees. Data of studying was analyzed by frequency statistics and Hierachical cluster analysis.

The distribution of tender points in the knee osteoarthritis was mainly in the interior region and anterior area such as in apex of patella, adductor tubercle and et al. According to the results of hierachical cluster analysis, the tender points could be divided into two categories the first cluster was in the interior region of knee, the second cluster was in the lateral region.

The findings demonstrated that cluster analysis statistical method can be used for classification of the distribution of tender points. The distribution features of tender points in knee osteoarthritis are related to the anatomic site in knee.