Investigation of the relationships of severity of tenderness in knee anatomic points measured by algometry in patients with knee osteoarthritis and radiographic changes of osteoarthritis and global patient complaints

Background The aim of this study was to compare the pain/tenderness severity of some determined anatomic points of knee region measured by using a pressure algometry in patients with knee OA with the patient's radiographic findings and global complaints. In this way, it is aimed to better understand the relationship between pain, radiological status and complaints during activities of daily living. Material and Methods The study was conducted on 67 patients (47 women, 20 men) who had symptomatic knee OA, and met the inclusion criteria of ACR. Algometric measurements were applied to determined anatomic points in the dominant knee. Knee pain and functional status of patients were evaluated with the Knee Injury and Osteoarthritis Outcome Score (KOOS). Knee radiographs were evaluated according to the Osteoarthritis Radiological Grading Classification by Kellgren-Lawrence and atlas of Altman and Gold as well. Joint space narrowing and osteophytic progression were graded in both tibiofemoral compartments and patellofemoral compartment. The relationships were analyzed statistically. Results In the study, the number of patients according to KL 2-4 grading groups were 13, 41 and 13, respectively. The mean age of the patients was 65.0±8.0. As the KL grade progressed, age and BMI increased, and the applied pressure force that triggering pain decreased with TPMed and TPLat increases. There was a negative correlation between KOOSFUNC score and TFEMedDar, PFELatDar, PFEMedOs and PFELatOs grading. A negative correlation was found between KOOSPAIN score and TFEMedDar and PFELatDar grading. There was a negative correlation between the TFESclerosis grade and the pressure causing pain in PM, and the TFELatDar grading and the pain triggering pressure threshold in TPMed, between the TFEMedDar grade and the pain triggering pressure threshold in the TPLat, and between the TFELatDar grade and the pain triggering pressure threshold in the TPLat. Conclusions Standard radiographic evaluation of knee may not fully reflect the clinical condition of the patient in OA. Examining the effects of compartment specific joint space narrowing and osteophytic progression on pain and functional status may provide a better understanding of the relationship between knee pain due to OA and radiographical status and activities of daily living. While evaluating the patients with knee OA, it might be useful to measure the pain severity and sensitivity with an algometer, in addition to patient reported knee pain questionnaires, as it standardizes assessment with palpation and pressing during physical examination. Key words: Joint; knee; osteoarthritis; pain