Polish Validation and Language Adaptation of the Banff Patellofemoral Instability Instrument 2.0

The importance of patient-reported outcome measures (PROMs) is becoming increasingly recognized in the orthopaedic field. The Banff Patellofemoral Instability Instrument 2.0 (BPII 2.0) is a disease-specific tool designed for patients with patellofemoral instability.

To adapt, translate, and validate the BPII 2.0 into Polish, to enable its use by Polish-speaking professionals for the evaluation of patients who present with patellofemoral instability.

Cohort study (Diagnosis); Level of evidence, 3.

The final Polish version of the BPII 2.0 was investigated in patients with a confirmed diagnosis of recurrent patellofemoral joint (PFJ) instability. Patients completed 2 sets of PROMs, the BPII 2.0, Anterior Knee Pain Scale (Kujala), Norwich Patellar Instability (NPI) score, Lysholm knee score, and International Knee Documentation Committee [IKDC] Subjective Knee Form, at the clinic visit and 7 to 14 days later. The following psychometric properties were assessed: face validity, floor and ceiling effects, test-retest reliability, internal consistency, construct validity, standard error of measurement (SEM), and minimal clinically important difference (MCID). The reliability was evaluated by measuring the internal consistency (Cronbach alpha) and test-retest reliability (intraclass correlation coefficient). Pearson correlation coefficients were used to examine the validity.

The study population consisted of 80 postoperative patients (29 males, 51 females) aged 12 to 37 years with a confirmed diagnosis of recurrent PFJ instability. Face validity was assessed with an expert clinician group and an expert-patient group. No floor or ceiling effects were observed. The test-retest reliability of the BPII was 0.995 (P < .01). The BPII 2.0 score demonstrated excellent internal consistency, with a Cronbach alpha of 0.95 at baseline and 0.96 at the retest.The correlations of the BPII with the other PROMs were statistically significant and classified as moderate to strong: IKDC Subjective Knee Form (Pearson rho = 0.725; P < .001), Lysholm score (rho = 0.58; P < .001), and Kujala score (rho = 0.533; P < .001). A significant negative correlation of moderate strength between the BPII and NPI score (rho = -0.615; P < .001) was calculated. The SEM was estimated at 1.329 and the MCID was 3.028.

This study demonstrated that the Polish version of the BPII 2.0 is a reliable and valid instrument for Polish-speaking patients with recurrent patellofemoral instability. It will enable multicenter, international studies through uniform application of the functional assessment of patients with PFJ instability.