What is the “Kujala Score”?
The “Kujala Score” is the eponymous name for the Anterior Knee Pain Scale (AKPS). It is a patient-reported outcome survey and diagnostic tool that aims to assess the severity of symptoms and physical limitations in patients with patellofemoral pain syndrome (PFPS). It was initially derived due to the diagnostic inconsistency among other tools that were used with PFPS patients (1).
The Kujala Score was developed and reported in 1993 by Dr. Urho Kujala and associates (2). Since its introduction, multiple studies have evaluated its clinimetric properties and have established it as the preferred measure for PFPS (3,4). As a result, a systematic review in 2018 found that 72% of studies evaluating PFPS used the Kujala Score (5).
The Kujala Score has been translated and validated in many languages including Spanish, German, and Indonesian, among others (1,5).
Structure and Scoring
The Kujala Score is a self-administered questionnaire for PFPS patients consisting of 13 questions that relate to specified activities, pain severity, and clinical symptoms (1). It is scored out of 100 points, which represents the summation of the scores for each individual question. The questions, answers, and scores are detailed below:
Strengths
The Kujala Score demonstrates relatively high sensitivity and specificity at 80% and 90%, respectively, for PFPS (6). It demonstrates validity, reliability, and responsiveness in multiple languages (1). Crossley et al. found a moderate intraclass correlation coefficient (ICC) of 0.81 and a large effect size of 0.98 (4). They also reported a minimum clinically important difference (MCID) of 10. Watson et al. found an ICC of 0.95 and a satisfactory receiver-operating characteristic (ROC) curve of 0.69 (3). It is widely used and could potentially standardize the evaluation of PFPS outcomes.
Considerations
The Kujala Score could be limited by patient understanding and level of education given its self-administration. The tool is mostly used for PFPS but still lacks generalizability to other knee pathologies.
Licensing
The Kujala Score is free to use and does not have any licensing requirements. To view the Kujala scores, please visit this website.
Resources
(1) Validity and reliability of the indonesian version of the kujala score for patients with patellofemoral pain syndrome | (2) Scoring of patellofemoral disorders | (3) Reliability and responsiveness of the lower extremity functional scale and the anterior knee pain scale in patients with anterior knee pain | (4) Analysis of outcome measures for persons with patellofemoral pain: which are reliable and valid? | (5) Validation of the German version of the Kujala score in patients with patellofemoral instability: a prospective multi-centre study | (6) Analysis of patient-reported anterior knee pain scale: implications for scale development in children and adolescents
