Background: Haglund’s deformity, which is characterized by a bony prominence of the posterosuperior aspect of the calcaneus, causes posterior heel pain. To date, there is no standard radiographic parameter to diagnose symptomatic Haglund’s deformity. Herein, we proposed novel radiographic measurements to distinguish between patients with and without symptomatic Haglund’s deformity. Methods: We retrospectively evaluated ankle radiographs of 43 patients who underwent surgery for symptomatic Haglund’s deformity (Haglund group) and 41 healthy individuals (control group) free of heel complaints. Fowler–Phillip angle (FPA), Heneghan–Pavlov parallel pitch lines (PPL), Haglund’s deformity height, bump height, and bump-calcaneus ratio were measured and compared between the groups. Furthermore, the reliability and cut-off value of each parameter were validated via ICC and ROC curve analysis, respectively. Results: The bump height (p < 0.001) and the bump-calcaneus ratio (p < 0.001) showed significant differences between the control and Haglund groups, unlike FPA, PPL, and Haglund’s deformity height. ROC curve analysis revealed that the AUC of bump-calcaneus ratio was larger than that of bump height. The optimal threshold was 4 mm or higher for bump height and 7.5% or higher for bump-calcaneus ratio. The intra- and inter- observer ICCs were, respectively, 0.965 and 0.898 for bump height and 0.930 and 0.889 for bump-calcaneus ratio. Conclusions: This study proposes two novel radiographic parameters to identify operatively treated Haglund’s deformity, namely bump height and bump-calcaneus ratio. They are easy to measure and intuitive. Both of them are effective diagnostic parameters for Haglund’s deformity. Furthermore, bump-calcaneus ratio is more reliable diagnostic parameter than bump height.

This study investigated the differences in ankle alignment changes after TKA in patients with varying preexisting ankle deformities. We retrospectively examined 90 knees with osteoarthritis and varus deformity in 78 patients who underwent TKA. Preoperative and postoperative radiographic parameters were analyzed. According to their preexisting ankle deformity, patients were assigned to the valgus or varus group. Overall, 14 (15.6%) cases were of preoperative valgus ankle deformity; the remainder were of preoperative varus ankle deformity. Hip–knee–ankle angle (HKA), tibial plafond–ground angle (PGA), and talus–ground angle (TGA) all exhibited significant correction in both groups; however, tibial plafond–talus angle (PTA) and superior space of ankle joint (SS) only changed in the varus group. The median PTA and SS significantly decreased from 1.2° to 0.3° (p < 0.001) and increased from 2.5 to 2.6 mm (p = 0.013), respectively. Notably, ∆PTA positively correlated with ∆HKA in the varus group (r = 0.247, p = 0.032) but not in the valgus group. Between-group differences in postoperative PTA (p < 0.001) and ∆PTA (p < 0.001) were significant. The degree of ankle alignment correction after TKA differed between patients with preexisting varus and valgus ankle deformities. TKA could not effectively correct the preexisting ankle valgus malalignment.

Purpose: Maintaining gap balance is critical for total knee arthroplasty (TKA). This study aimed to elucidate if the extension–flexion gaps would be changed with posterior cruciate ligament (PCL) intact (PI) and PCL resection (PR) during TKA. The flexion gaps were measured using two methods, open-(Fo) and closed-chain position (Fc), based on the definition of kinetic chain position, respectively. Methods: This retrospective study enrolled a total of 33 patients who underwent posterior-stabilized (PS) TKA for symptomatic advanced osteoarthritis of knees. After bone cuts were completed, the extension–flexion gaps before and after PCL resection during TKA were measured using a calibrated tensioning device set at a 100 Nm distraction force. To further differentiate the effect of thigh weight on the 90° flexion gap, two varied methods of examination, either in closed chain (Fc) or open chain (Fo) were performed. Results: The increases in the 90° knee flexion gap after PCL resection were measured by both methods, i.e., ΔFc (PR-Fc—PI-Fc): 2.04 ± 2.06 mm, p < 0.001; and mean ΔFo (PR-Fo—PI-Fo): 1.64 ± 1.36 mm, p < 0.001. However, there were no differences between ΔFc and ΔFo before and after PCL resection. A greater amount of flexion gap was identified in open chain than in closed chain after PCL resection, and the PR-Fo and PR-Fc were 14.36 ± 3.13 and 11.40 ± 3.47 (p < 0.001), respectively. Conclusions: The resection of PCL during TKA distinctly increased the flexion gap, but not the extension gap. This disproportionate increase of the gap will cause a gap balance mismatch. The tensioning maneuver in open-chain was more effective to detect the gap differences than in closed-chain before and after PCL resection during TKA.

Introduction: Hallux valgus (HV) is a common foot deformity, with metatarsus adductus (MA) identified as a potential predisposing factor. MA has been shown to negatively affect surgical outcomes for HV, particularly in severe cases. This study aims to clarify the prevalence of MA in the HV population using different metatarsus adductus angle (MAA) measurement methods and assess whether MAAs are influenced by HV severity.Materials and Methods: This retrospective study included 294 feet from 147 participants. Patients were classified into non‐HV (normal) and HV subgroups, with HV severity graded as mild, moderate, or severe based on the hallux valgus angle (HVA) measured on dorsoplantar weight‐bearing radiographs. The prevalence of MA was assessed using four radiographic measurements: Sgarlato's MAA (MAA4), modified Sgarlato's MAA (MAA5), modified Engel's angle, and the calcaneo‐second metatarsal angle (rearfoot‐MT2). The interclass correlation coefficient was used to evaluate the reliability of the measurements. The correlation between HVA and MAA was analyzed using Spearman's Rho coefficient, and the prevalence of MA was compared using various measures.Results: After excluding 87 feet, 207 feet (146 HV and 61 non‐HV) from 147 participants were analyzed. All four MAA measurements showed excellent reliability, with the modified Engel's angle demonstrating the highest interobserver reliability and strongest correlation with HVA. HVA was significantly higher in the MA (+) group compared to the MA (−) group (32.21 vs. 24.78° and p = 0.001). The overall prevalence of MA in the cohort was 19.3% (MAA4), 24.2% (MAA5), 18.4% (modified Engel's angle), and 8.2% (rearfoot‐MT2). MA was significantly more prevalent in the HV group compared to the normal group (24.0% vs. 4.9%) when using the modified Engel's angle, with MA prevalence increasing as HV severity worsened.Conclusions: MA is common among patients with HV, with its prevalence increasing in parallel with HV severity. The modified Engel's angle is a reliable and sensitive method for detecting MA associated with HV, particularly in severe cases, and its use can help tailor surgical plans to improve outcomes. Surgeons should be mindful of the presence of concomitant MA when planning HV surgery, as it may negatively affect surgical outcomes and increase the risk of recurrence.