Correlation between the Q angle and the patella position: a clinical and axial computed tomography evaluation

• Published in: Archives of orthopaedic and trauma surgery Vol. 121; no. 6; pp. 346 - 349
• Main Authors: BIEDERT, R. M, WARNKE, K
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.06.2001; Springer Nature B.V
• Subjects: Adolescent; Adult; Biological and medical sciences; Bone Malalignment - diagnostic imaging; Child; Female; Humans; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Osteoarticular system. Muscles; Pain; Patella - anatomy & histology; Patella - diagnostic imaging; Prospective Studies; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Tomography, X-Ray Computed; Knee; Human; Radiodiagnosis; Methodology; Diseases of the osteoarticular system; Lower limb; Test reliability; Syndrome; Femoropatellar joint; Knee disease; Angular measurement; Sensitivity; Specificity; Pain; Correlation analysis; Patella; Medical imagery; Clinical investigation; Computerized axial tomography
• ISSN: 0936-8051; 1434-3916
• DOI: 10.1007/s004020000239

The purpose of this study was to evaluate the significance of the Q angle with respect to the patella position. Fifty-six knee joints of 34 patients (15 bilateral) with chronic patellofemoral pain were prospectively evaluated. All patients were examined by the same orthopaedic surgeon (R.M.B.) and the Q angle measured clinically and using long radiographs. Additionally, axial computed tomography (CT) scans were obtained through the center of the patellar articular cartilage in 0 degrees of flexion. Three different patellofemoral indices were measured by the second author (K.W.), who was not involved in the clinical examination: lateral patellar displacement (LPD), lateral patellar tilt (LPT), and patella-lateral condyle index (PLCI). These results were compared with the values of the measured Q angle. For statistical analysis, the Pearson correlation coefficient was calculated and the Statistical Package for Social Science (SPSS) used. A pvalue < 0.05 was considered significant. We could not find a significant correlation between the Q angle values and the patellofemoral indices in all patients (bilateral or only right/left). Within the patients with bilateral patellofemoral pain (n = 15), there was a significant correlation between LPD and PLCI (p = 0.015), LPT and PLCI (p = 0.024) left and LPD and LPT(p = 0.011) right. Similar results were found in patients with pain only on one side. In conclusion, there is no significance between the Q angle and the position of patella. The diagnostic relevance of the Q angle could not be established.