Gärtner Type and Outcomes After US PAL Versus Arthroscopic Debridement for Calcific Tendinitis: A Retrospective Cohort Study.

Abstract

To compare the efficacy of US-PAL and AD for calcific tendinitis stratified by Gärtner type, addressing whether calcification morphology influences treatment response-a question prior randomized trials were not designed to answer. This retrospective cohort study analyzed 72 patients with refractory calcific tendinitis who underwent either ultrasound-guided percutaneous aspiration and lavage (US-PAL) or arthroscopic debridement (AD) between June 2022 and June 2024. Propensity score matching was performed to minimize selection bias, yielding 35 patients per group. Subgroup analyses were stratified by Gärtner type (I vs. II). Outcomes included Visual Analog Scale (VAS), American Shoulder and Elbow Surgeons (ASES), and Constant-Murley scores assessed at baseline and 12 months postoperatively. A linear mixed-effects model was used to evaluate the treatment-by-Gärtner-type interaction. Both groups demonstrated significant improvement from baseline to 12 months across all outcome measures (all P < .001). A significant treatment-by-Gärtner-type interaction was observed (coefficient = 16.85; 95% CI: 9.92-23.79; P < .001). In Gärtner Type I calcifications, AD was associated with superior ASES (difference: 12.8 points) and Constant-Murley (difference: 11.6 points) scores compared with US-PAL (both P < .001), with differences exceeding minimal clinically important difference (MCID) thresholds. In Gärtner Type II calcifications, no significant between-group differences were detected (all P > .05), and all differences remained below MCID thresholds. US-PAL was associated with shorter operative time and lower cost (P < .05). The Gärtner classification was associated with differential treatment outcomes in this retrospective cohort. For Type II calcifications, US-PAL demonstrated non-inferior efficacy to AD, with shorter operative time and lower cost. For Type I calcifications, AD was associated with superior functional improvement. These findings suggest that this imaging-based classification may assist in treatment selection, although prospective validation is required.