F. Hegazy1, E. Aboelnasr2, P. Kumar3, A. Almaz2, I.-J. Kim4
1University of Sharjah, Physiotherapy, Sharjah, United Arab Emirates, 2Cairo University, Physical Therapy, Cairo, Egypt, 3Gulf Medical University, Physiotherapy, Ajman, United Arab Emirates, 4University of Sharjah, College of Engineering, Sharjah, United Arab Emirates
Background: Clinical diagnosis of Paediatric flexible flatfoot is still a challenging issue for the healthcare professionals. Clark’s Angle (CA) is frequently used clinically for assessing foot posture; however there is still a debate about its validity and diagnostic accuracy in evaluation of static foot posture especially in Paediatric population with some previous studies supporting, while the others are refuting its validity.
Purpose: To investigate validity and diagnostic accuracy of CA using radiographic findings as a criterion standard measure to determine Paediatric flexible flatfoot between ages of 6-18 years.
Methods: A cross-sectional study conducted on 612 participants (1224 feet) with flexible flatfoot aged 6-18 years (13.64 ±3.50) was recruited. The clinical measures results were compared to the criterion standard radiographic measures and displayed on the receiver operating characteristic curve (ROC) and the area under ROC curve (AUC) was computed. Intra-rater reliability, sensitivity, specificity, predictive values, and likelihood ratios were calculated for CA. Fagan nomogram was used to detect the posttest probability of flatfoot.
Results: Clarke’s angle (CA) demonstrated higher intra-rater reliability (ICC=0.99). CA showed a high sensitivity (98.4%), specificity (98.8), positive predictive value (97.3) and negative predictive value (99.3).The positive likelihood ratio was 82 and the negative likelihood ratio was 0.02. AUC was 0.98[95%CI= 0.95-1.00]. The positive likelihood ratio (LR+) yielded a posttest probability of 97%, while the negative likelihood ratio (LR−) yielded a posttest probability of 1%.
Conclusion(s): CA is a valid and diagnostically accurate clinical measure in assessment of Paediatric flexible flatfoot between ages of 6-18 years.
Implications: flatfoot is found to be associated with the development of various lower limbs musculoskeletal disorders, so, finding the most accurate clinical measure for quantifying static foot posture in Paediatric populations is valuable either to the clinical practitioners or researchers. the current study provide a proof about the validity, predictive capacity and diagnostic accuracy of CA in Paediatric population, that will help clinicians to be more confident about diagnosis and to detect static foot posture pathology without a need for further radiographic investigation with the risk of irradiation exposure. Consequently, that will have a positive effect on improving and upgrading the evidence-based clinical practice.
Funding, acknowledgements: N/A
Keywords: Validity, Diagnostic Accuracy, Clarke’s angle, Paediatric Flatfoot
Topic: Paediatrics
Did this work require ethics approval? Yes
Institution: Cairo University
Committee: The Research Ethical Committee
Ethics number: No: P.T.REC/10/002366
All authors, affiliations and abstracts have been published as submitted.
