Pelvic width is not associated with patellofemoral alignment in Asian patients with anterior knee pain: A...

Patellofemoral maltracking is a leading cause of anterior knee pain (AKP), yet current diagnostic paradigms largely focus on distal alignment parameters while the contribution of proximal skeletal morphology remains unclear. Pelvic width (PW) has been hypothesized to influence femoral orientation and extensor mechanism alignment; however, its relationship with patellofemoral alignment is poorly defined, particularly in Asian populations where pelvic morphology differs from Western cohorts. This study aimed to evaluate the association between PW and radiological patellofemoral alignment parameters, and to assess sex-based differences in pelvic morphology and patellofemoral characteristics in patients with AKP.

A cross-sectional study was conducted involving 100 consecutive patients (50 men, 50 women; age 17-65 years) presenting with AKP. Full-length standing scanograms were used to measure PW (distance between bilateral anterior superior iliac spines), and hip-knee-ankle (HKA) angle. Noncontrast 3.0-T knee magnetic resonance imaging (MRI) was performed to assess patellar tilt angle (PTA), sulcus angle (SA), tibial tubercle-trochlear groove (TT-TG) distance, Insall-Salvati (IS) ratio, and bisect offset (BO). Continuous variables were compared between sexes using appropriate parametric or nonparametric tests based on data distribution. Correlations between PW and patellofemoral parameters were assessed using Spearman's rank correlation. Key patellofemoral parameters were additionally analyzed categorically using established clinical thresholds, with between-sex comparisons performed using Fisher's exact test.

Pelvic width did not differ statistically significantly between male and female patients and showed no statistically significant association with patellofemoral alignment or tracking parameters, whether analyzed as continuous variables or categorical groups. No correlations were observed between PW and all patellofemoral parameters group. In contrast, females demonstrated a statistically significant higher prevalence of shallow SA (≥145°) compared with males (P < 0.05). Secondary analyses revealed statistically significant strong correlations among established patellofemoral parameters including between PTA category and BO category, and between TT-TG category and BO category, confirming internal biomechanical coherence.

Pelvic width neither differs by sex nor statistically significantly influences patellofemoral alignment or maltracking in Asian patients with AKP, whereas local patellofemoral morphology-particularly trochlear anatomy-appears to be the primary structural determinant of patellofemoral pain.

III Observational Studies.