Influence of bump height and bump–calcaneus ratio on clinical outcomes following calcaneoplasty for Haglund’s deformity: a prospective study

Endoscopic calcaneoplasty has gained increasing popularity in recent years for the treatment of Haglund’s deformity, which is characterized by a posterosuperior calcaneal prominence and associated retrocalcaneal bursitis. However, the relationship between preoperative calcaneal morphological parameters and postoperative clinical outcomes remains unclear. Therefore, the aim of this study was to investigate whether bump height and the bump–calcaneus ratio, measured on preoperative radiographs, are associated with clinical or radiological outcomes following endoscopic calcaneoplasty. A prospective evaluation was conducted on 22 feet in 22 patients who underwent endoscopic calcaneoplasty. Demographic data and radiographic parameters including bump height, bump-to-calcaneus ratio, and various angular measurements were recorded. Clinical outcomes were assessed using the American Orthopaedic Foot & Ankle Society (AOFAS) score and visual analog scale (VAS) preoperatively and at 1, 3, 6, and 12 months postoperatively. Normality was assessed with Shapiro-Wilk test, and non-parametric tests were used for all analyses. Effect sizes (Cohen’s d) were calculated from Wilcoxon Z statistics. Minimal clinically important difference (MCID) was evaluated by comparing AOFAS improvement with literature values. Bonferroni correction was applied for multiple comparisons. The mean patient age was 46.2 ± 13.1 years, and the mean follow-up duration was 14 ± 2 months. The mean operative time was 63 ± 27 min. Both AOFAS and VAS scores demonstrated statistically significant improvement at all time points (p < 0.001), with large effect sizes (d = 1.75 for AOFAS, d = 1.76 for VAS). The mean Δ AOFAS at 12 months (41.1 ± 24.1) exceeded the established MCID range, confirming clinically meaningful improvement. No significant associations were identified between preoperative bump height or bump-to-calcaneus ratio and clinical outcomes (p > 0.05). No surgical complications or infections were observed. Endoscopic calcaneoplasty resulted in significant clinical improvement in patients with Haglund’s deformity, with substantial increases in AOFAS scores and reductions in VAS pain scores. In this cohort, no significant association was observed between preoperative bump height, bump–calcaneus ratio, and postoperative clinical outcomes. However, the relatively small sample size limits the generalizability of these findings, and larger prospective studies are warranted.