Differential Radiographic Response of Sagittal Foot Alignment to Early Weight Loss Following Sleeve Gastrectomy

Background and Objectives: We aimed to evaluate early postoperative radiographic changes in sagittal foot alignment following laparoscopic sleeve gastrectomy and to investigate the association between early weight loss and sagittal foot alignment parameters. Materials and Methods: This study included 72 consecutive patients who underwent primary laparoscopic sleeve gastrectomy. Standardized lateral foot radiographs were obtained preoperatively and at the fourth postoperative month. Meary's angle, calcaneal pitch, and talar declination angle were measured on all radiographs. Demographic and clinical variables, including age, sex, height, body weight, and body mass index (BMI), were recorded. Results: Meary's angle demonstrated a significant postoperative decrease from 15° (IQR, 8°) to 11° (IQR, 12°) (p < 0.001), indicating improvement in medial longitudinal arch alignment. In contrast, no significant postoperative changes were observed in the calcaneal pitch (p = 0.227) or talar declination angles (p = 0.751). The proportion of patients within the normal range for all measured sagittal alignment parameters increased postoperatively, without showing statistical significance. Statistical analysis revealed that all postoperative sagittal alignment parameters showed significant correlation with preoperative values. Notably, postoperative Meary's angle demonstrated a very strong positive correlation with preoperative Meary's angle (r = 0.80, p < 0.001), whereas no significant correlation was identified between postoperative Meary's angle and either postoperative weight or weight/BMI loss (p > 0.05). Although BMI loss showed a significant correlation with postoperative calcaneal pitch and talar declination angles, these correlations were weak to moderate (r = -0.403, and r = -0.362, respectively). Conclusions: Early postoperative body weight/BMI loss following sleeve gastrectomy is associated with modest, parameter-specific improvements in sagittal foot alignment, primarily reflected by changes in Meary's angle, suggesting that the medial longitudinal arch may be more responsive to early postoperative unloading than other sagittal alignment parameters. The strong association between preoperative and postoperative measurements underscores the central role of baseline alignment in determining early postoperative outcomes.