Translation, cross-cultural adaptation and establishment of psychometric properties of the Gujarati version of Kujala patellofemoral score in subjects with anterior knee pain

Translation, cross-cultural adaptation and establishment of psychometric properties of the Gujarati version of Kujala patellofemoral score in subjects with anterior knee pain

Ethical clearance will be obtained from the institutional ethics committee, adhering to the Declaration of Helsinki. Subjects with anterior knee pain, diagnosed by an orthopaedic surgeon, will be included based on specific criteria. All participants will provide written informed consent and demographic information.

Phase 1: Translation and Cross-Cultural Adaptation

The Kujala Patellofemoral Score (KPS) will be translated into Gujarati using a methodical process. Two translations will be performed independently by an orthopaedic surgeon and a professional translator. These will be synthesized into a consensus version, which will then be back-translated into English by two Gujarati-speaking translators. Both the translations and back-translations will be reviewed in consensus meetings. The nearly final Gujarati version will be pre-tested with 30 subjects experiencing anterior knee pain to ensure all items are clear and comprehensible.

Phase 2: Assessment of Psychometric Properties

1. Reliability: The KPS-G’s test-retest reliability will be evaluated with 30 subjects who will complete the questionnaire twice, 48 hours apart.
2. Face Validity: Assessed by asking patients if they find the scale relevant to their condition, with responses recorded as "yes" or "no."
3. Content Validity: Evaluated by experts using a Likert scale (0-6) to assess content equivalence, relevance, and representativeness.
4. Concurrent Validity: Measured by comparing the KPS-G with the WOMAC score.
5. Construct Validity:

• Convergent Validity: Assessed by comparing the KPS-G with the Lysholm knee score.
• Divergent Validity: Assessed by comparing the KPS-G with the SF-12 questionnaire.