Clinical outcomes of hyaluronic acid–sorbitol injection in athletes with patellofemoral pain: Evaluation of the potential influence of body mass index

Background Patellofemoral pain (PFP) is a frequent cause of activity-related knee pain and functional limitation in athletic populations. Elevated body mass index (BMI) may contribute to patellofemoral joint loading, but evidence on hyaluronic acid–sorbitol injection outcomes in athletes with elevated BMI remains limited. Objective To describe longitudinal changes in knee function and symptoms over 6 months after intra-articular hyaluronic acid–sorbitol injection in athletes with PFP, and to explore whether baseline BMI was associated with post-injection improvement. Methods This prospective, single-arm, non-randomized interventional study included 60 athletes aged 30–55 years who received a single 4 mL intra-articular hyaluronic acid–sorbitol injection. IKDC and KOOS scores were assessed at baseline, 15 days, 3 months, and 6 months. Longitudinal changes were evaluated using linear mixed models, with generalized estimating equations as a sensitivity analysis; exploratory regression and subgroup analyses assessed the association between BMI and improvement. Results Mean IKDC and KOOS scores increased from baseline to 6 months, with estimated changes of +18.58 points for IKDC (95% CI 16.81–20.36) and +19.28 points for KOOS (95% CI 17.52–21.04; both p < 0.001). At 6 months, 75.0% of participants reached the predefined IKDC threshold for clinically meaningful improvement and 83.3% reached the KOOS threshold. Participants with BMI ≥ 25 kg/m 2 also showed within-group improvement. BMI was not independently associated with improvement rate after adjustment for baseline score; however, the small elevated-BMI subgroup ( n = 22) limited these exploratory comparisons, and a clinically relevant difference could not be excluded. Minor local adverse events occurred in 4 of 60 participants and resolved with cryotherapy. Conclusion Athletes with PFP, including those with elevated BMI, showed consistent improvement in knee function and symptoms over 6 months following hyaluronic acid–sorbitol injection. These findings support intra-articular hyaluronic acid–sorbitol as a feasible, well-tolerated option for athletes with PFP, regardless of body weight. Controlled trials are needed to confirm the treatment’s contribution, given the single-arm design. Trial Registration CEI/0504/PI/2022; ClinicalTrials.gov NCT05450458 .