Abstract: Recurrent or persistent intractable pain is quite common after surgical intervention, such as joint replacement. However, the biomechanics and biological factors inside and outside the joint make it difficult to identify the potential cause and precise painful sites. Although anatomical images can provide information on the biomechanical and anatomical changes around the prosthesis, it is impossible to identify the site and cause of pain after joint replacement. To show the distribution and identify intra -articular biomechanics and other structural alterations, bone tracers such as ⁹⁹Tc^m-MDP are used. Three-phase ⁹⁹Tc^m-MDP bone scintigraphy and hybrid SPECT/CT images can allow the identification of metabolic alterations caused by changes in metabolic activity and bone reaction. This review presents the clinical indications of artificial joint replacements, etiologies of postoperative pain, and clinical applications of fused SPECT/CT images in pain evaluation after hip or knee joint replacement.