Correlation Between the Severity of Pain and Radiographic Findings in Hip Osteoarthritis

Abstract

AIM: To analyze the association between the severity of pain and individual radiographic features and global radiographic indexes in hip osteoarthritis (OA). Materials and Methods: Forty-five consecutive patients who attended to our outpatient clinic with hip pain diagnosed as hip OA according to American College of Rheumatology (ACR) criteria were recruited for the study. Anteroposterior pelvic radiographs were obtained in all patients. Radiographs were read blindly and evaluated using Croft index, Lane index, individual radiographic features (IRF) of Lane index and Croft’s measurement of the “minimal joint space” (MJS) and Kellgren-Lawrence grading by a radiologist. After radiographic evaluation Kellgren Lawrence grade 1 patients were excluded from the study and 38 patients with Kelgren Lawrence grade 2-4 hip OA patients were statistically analyzed. Correlation between the severity of pain evaluated by visual analog scale (VAS) and radiographic findings were statistically analyzed with Spearman correlation test. Linear regression analyses (stepwise method) were used to investigate associations between severity of pain and radiographic findings. JSN and osteophyte grading according to Lane index, MJS, MJS<2.5 mm and global indexes (KL,Croft,Lane) were chosen as independent variables in linear regression analyses. Results: Mean age of patients was 60.76+13 years. 38 patients had Kellgren Lawrence grade 2-4 hip osteoarthritis. Joint space narrowing (JSN) grading according to Lane index (r =0.32 and p=0.05) and minimal joint space measurement <2.5 mm according to Croft index (r = -0.33 and p=0.04) showed correlation with severity of pain. No correlation was observed between osteophyte grading, sclerosis, cyst, deformity and global indexes and severity of pain (p> 0.05). Applying logistic regression analyses, only reduced minimum joint space (MJS) (cut off value set at 2.5 mm) was found to be significantly associated to the severity of pain (p=0.002.) Conclusion: Quantitative measurement and grading of joint space narrowing showed correlation with severity of pain in hip osteoarthritis patients. It is observed that the radiographic finding that is related to the severity of pain in hip OA was MJS< 2.5 mm. This finding should be confirmed with further studies of larger sample size of patients with different radiographic severity.