Pain in osteochondral lesions.

Pain is the key symptom of patients suffering from osteochondral lesions (OCLs) of the ankle joint. Routine radiographic imaging methods for diagnosis and staging of OCL fail to visualize the pain-inducing focus within the joint. SPECT-CT (Single-photon emission computed tomography-computed tomography) is a new hybrid imaging technique allowing exact digital fusion of scintigraphic and computer tomographic images. This allows precise localization and size determination of an OCL within the joint. Using this novel imaging method, we conducted a study to evaluate the correlation between pathological uptake within an OCL and pain experienced by patients suffering from this condition; 15 patients were assessed in the orthopaedic ambulatory clinic for unilateral OCL of the ankle joint. Pain status was measured with the Visual Analogue Scale (VAS). A SPECT-CT was performed. All patients underwent CT-guided ankle injection with a local anesthetic and iodine contrast medium. The VAS score assessed immediately postinfiltration was compared with the preinterventional VAS score obtained in the outpatient clinic. Pain relief was defined as a reduction of the VAS score to ≤50% of the preinterventional score, if expected immediately after infiltration. Pain relief was found in all 15 patients. The results of our study show that there is a highly significant correlation between pain and pathological uptake seen on SPECT-CT, indicating that pathologically remodeled bone tissue is an important contributor to pain in OCL. Adequate addressing of involved bone tissue needs to be taken into consideration when choosing a surgical treatment method.