Improving Striae Distensae With Combined Hyperdiluted Calcium Hydroxylapatite Injection and Fractional Microneedling Radiofrequency: A Pilot Study.

Striae distensae (SD), or stretch marks, are dermal scars resulting from disrupted collagen and elastin because of mechanical stress. Effective treatments, particularly for chronic striae alba, remain limited. Calcium hydroxylapatite (CaHA), a biostimulatory dermal filler, and fractional microneedling radiofrequency (RF) have individually demonstrated regenerative effects. This pilot study investigates the safety and efficacy of combining CaHA and fractional microneedling RF in improving SD. Eight female patients with abdominal SD (rubra or alba) underwent 1 session of hyperdiluted CaHA injection (1:4 dilution, 3 mL), followed by 3 monthly sessions of RF microneedling. Outcomes were evaluated 6 months after the final session using the Manchester Scar Scale (MSS), patient satisfaction scores, and adverse event monitoring. All participants (mean age 36.6 ± 7.3 years) completed the protocol. Mean MSS scores improved significantly from 14 ± 0.93 at baseline to 6.88 ± 1.64 posttreatment (P < .0001). The mean satisfaction score was 8.12 ± 1.72. Mild, transient erythema occurred in 2 cases; no serious adverse events were observed. This pilot study suggests that combining hyperdiluted CaHA with RF microneedling is a safe and effective approach for treating SD, yielding both clinical and patient-reported improvements. Larger controlled studies are warranted. Level of Evidence: 4 (Therapeutic) For image description, please refer to the figure legend and surrounding text.