Transverse incisions improve scar outcomes in anterolateral supine approach total hip arthroplasty: a patient observer scar assessment scale-based study

BACKGROUND: This study compared transverse and longitudinal skin incisions in anterolateral supine (ALS) total hip arthroplasty (THA), focusing on cosmetic and sensory outcomes using the Patient Observer Scar Assessment Scale (POSAS). METHODS: A retrospective analysis was conducted on 132 hips that underwent primary ALS THA performed by a single surgeon between 2019 and 2024. Longitudinal incisions were used until December 2022, and transverse incisions aligned with relaxed skin tension lines were used thereafter. POSAS 3.0 was used to evaluate scar quality across satisfaction, appearance, and sensory domains. RESULTS: Baseline characteristics were similar between groups, except for follow-up duration and incision length. No significant differences were found in POSAS scores. However, regression analysis revealed that transverse incision significantly improved satisfaction (P = 0.04) and appearance (P < 0.05). Sensory scores were significantly affected by follow-up duration (P < 0.001). CONCLUSION: Transverse incisions in ALS THA may enhance cosmetic satisfaction without compromising sensory outcomes. These findings support the potential role of personalized incision planning for improving patient-reported outcomes following THA. Video Abstract.