In patients with suspected osteoarthritis, start with a thorough histo
ry aimed at finding the mechanical component of the condition. Ask abo
ut past and current activities that may be loading or stressing a pain
ful joint. Conditions to consider in the differential diagnosis are th
ose affecting soft tissues-muscles, tendons, ligaments, and bursae. In
jecting the tender area with lidocaine will help identify a separate o
r coexisting soft tissue disorder. Before considering drug therapy, at
tempt to correct any mechanical factors that may be contributing to th
e problem. Modify the patient's exercise routine, if necessary, and be
gin patients on a walking aid if a weight-bearing joint is affected.