Diagnostic Accuracy of a Self-report Measure of Patellar Tendinopathy in Youth Basketball

Background: To engage clinicians in diagnosing patellar tendinopathy in large surveillance studies is often impracticable. The Oslo Sports Trauma Research Centre-patellar tendinopathy (OSTRC-P) questionnaire, a self-report measure adapted from the OSTRC questionnaire, may provide a viable alternative.

Objectives: To evaluate the diagnostic accuracy of the OSTRC-P questionnaire in detecting patellar tendinopathy in youth basketball players when compared to clinical evaluation.

Methods: Following the STAndards for Reporting of Diagnostic accuracy studies guidelines, the researchers recruited 208 youth basketball players (13-18 years of age) for this prospective diagnostic accuracy validation study. Participants completed the OSTRC-P questionnaire (index test) prior to a clinical evaluation (reference standard) by a physical therapist blinded to OSTRC-P questionnaire results. Sensitivity, specificity, predictive value, likelihood ratio, and posttest probability were calculated. Linear regression was used to examine the association between the OSTRC-P questionnaire severity score and the patellar tendinopathy severity rating during a single-leg decline squat.

Results: The final analysis included 169 players. The OSTRC-P questionnaire had a sensitivity of 79% (95% confidence interval [CI]: 65%, 90%), specificity of 98% (95% CI: 94%, 100%), positive predictive value of 95% (95% CI: 83%, 99%), negative predictive value of 92% (95% CI: 86%, 96%), positive likelihood ratio of 48 (95% CI: 12, 191), and negative likelihood ratio of 0.21 (95% CI: 0.12, 0.37). The posttest probabilities were 95% and 8%, given positive and negative results, respectively. A positive association was found between OSTRC-P questionnaire severity score and single-leg decline squat rating (β = 0.08; 95% CI: 0.03, 0.12; P = .001).

Conclusion: The OSTRC-P questionnaire is an acceptable alternative to clinical evaluation for self-reporting patellar tendinopathy and grading its severity in settings involving youth basketball players.

Level of evidence: Diagnosis, level 1b. J Orthop Sports Phys Ther 2018;48(10):758-766. Epub 27 Apr 2018. doi:10.2519/jospt.2018.8088.