[Objectification of Skin Quality in Flap Reconstructions using the Cuto-, Mexa-, and Tewameter: A Comparative Analysis of Sural and ALT Flap Techniques].

The reconstruction of full-thickness soft tissue injuries on the distal lower extremity depends on the defect size, the patient's risk profile and comorbidities. A pedicled sural flap or a free ALT flap are standard procedures for restoring the tissue. To compare the skin and scar quality of the two reconstructive options, subjective patient perception and satisfaction as well as the objective skin properties were examined using the Patient and Observer Scar Assessment Scale (POSAS), Cuto-, Mexa-, and Tewameter.This retrospective study included 40 patients who received a pedicled sural flap or a free ALT flap for tissue reconstruction on the distal lower extremity between 2013 and 2018. A subjective assessment of skin quality was conducted using the POSAS and a visual analogue scale to determine patients' perception and satisfaction with the surgical results. Skin quality was analysed using a Cuto-, Mexa-, and Tewameter in the flap area, the area surrounding the flap, the healthy contralateral side, the donor site, and the corresponding contralateral side of the donor site.The examination of the subjectively perceived skin and scar quality showed a significantly higher level of satisfaction among patients with ALT flaps than among patients with sural flaps. The POSAS evaluation showed better skin quality at the ALT donor site compared with the sural donor site. The melanin and erythema values recorded by the Mexameter revealed a positive correlation with the POSAS data. In an intra-individual skin comparison, the objective measurements demonstrated that both flaps exhibit reduced elasticity, while both donor sites show increased elasticity compared with the healthy contralateral side. In addition, an increased erythema value was found at the flaps and donor sites compared with the healthy opposite side.The instrument-based measurement methods exhibited objective differences in the skin properties of the examined skin areas. A correlation analysis between subjective perception and objective measurement data demonstrated that visual properties, such as melanin content and erythema, showed a stronger correlation with subjective perception than mechanical properties. Overall, patients with an ALT flap were more satisfied than patients with a sural flap, which can be attributed to a lower morbidity of the donor site.