Background/Objectives Hallux valgus (HV) is a prevalent three-dimensional foot deformity, yet it is primarily assessed in the anteroposterior plane radiographs. The role of the sagittal plane and specifically the plantar fat pad remains poorly understood. This study aimed to quantitatively explore the relationship between plantar fat-pad geometry and HV progression. Methods In this retrospective study, we analysed 274 feet from 144 patients who underwent HV corrective surgery at Hasharon Hospital, Israel (2014–2024). Using custom Python-based software, we annotated 22 anatomical landmarks on preoperative, weight-bearing lateral radiographs (3 plantar fat pads and 19 plantar bony points). For each fat pad, 19 Distance features were generated (total 57), comprising 19 pairwise standardised distances. Associations between these distances and standard HV angles (HVA, IMA, DMAA, HIA) were assessed using Pearson and Spearman correlations, A subgroup analysis was carried out to compare patients aged below and above 40 years, as well as between male and female patients. Results In the full cohort, no distance feature correlated with standard HV angles at the prespecified threshold (<InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(\:\left|r\right|\)</EquationSource> </InlineEquation> or <InlineEquation ID="IEq2"> <EquationSource Format="TEX">\(\:\left|\rho\:\right|\ge\:0.25\)</EquationSource> </InlineEquation>, two-sided <InlineEquation ID="IEq3"> <EquationSource Format="TEX">\(\:p<0.05\)</EquationSource> </InlineEquation>). Stratified analyses revealed subgroup-specific patterns: females showed three significant relationships (mainly involving the calcaneal fat pad), whereas males showed 29 predominantly negative forefoot–hindfoot correlations (e.g., base of 5th metatarsal fat pad <InlineEquation ID="IEq4"> <EquationSource Format="TEX">\(\:\to\:\)</EquationSource> </InlineEquation> calcaneal fat pad vs. HIA: <InlineEquation ID="IEq5"> <EquationSource Format="TEX">\(\:r=-0.44\)</EquationSource> </InlineEquation>, <InlineEquation ID="IEq6"> <EquationSource Format="TEX">\(\:\rho\:=-0.39\)</EquationSource> </InlineEquation>, both <InlineEquation ID="IEq7"> <EquationSource Format="TEX">\(\:p<0.01\)</EquationSource> </InlineEquation>). The <InlineEquation ID="IEq8"> <EquationSource Format="TEX">\(\:<40\)</EquationSource> </InlineEquation> y group exhibited six significant features (including sesamoid-based positives), while the <InlineEquation ID="IEq9"> <EquationSource Format="TEX">\(\:\ge\:40\)</EquationSource> </InlineEquation> y group showed two first-ray–focused associations. Several effects were stronger on Spearman than Pearson, consistent with nonlinearity, and many between-group differences were significant by Fisher’s <InlineEquation ID="IEq10"> <EquationSource Format="TEX">\(\:r\)</EquationSource> </InlineEquation>-to-<InlineEquation ID="IEq11"> <EquationSource Format="TEX">\(\:z\)</EquationSource> </InlineEquation> (<InlineEquation ID="IEq12"> <EquationSource Format="TEX">\(\:p<0.05\)</EquationSource> </InlineEquation>). Progressive Distance Mapping (PDM) summarized these effects into composite, radiograph-overlaid maps. Conclusions Progressive Distance Mapping (PDM) may suggest subgroup-dependent, progressive associations between plantar fat–pad–anchored distance geometry and hallux valgus (HV) severity. Despite no universal cohort-level correlations, PDM identifies four distinct morphologic subtypes within each subgroup (stratified by age and sex), this may suggest differing pathogenesis and patterns of plantar fat-pad involvement. These subtype-specific signatures are often nonlinear;

Progressive distance mapping of the plantar fat pad in hallux valgus reveals subgroup-specific morphologic subtypes

期刊论文
出版模式：

开放获取
发表日期：

2026年1月6日

查看全文

Hamza Murad,
Muhammad Khatib,
Assil Mahamid,
Feras Qawasmi,
Dror Robinson,
Eitan Lavon,
Loai Abdallah,
Mohamad Eisa,
Mohammad Shehadeh,
Mustafa Yassin

摘要

Background/Objectives

Hallux valgus (HV) is a prevalent three-dimensional foot deformity, yet it is primarily assessed in the anteroposterior plane radiographs. The role of the sagittal plane and specifically the plantar fat pad remains poorly understood. This study aimed to quantitatively explore the relationship between plantar fat-pad geometry and HV progression.

Methods

In this retrospective study, we analysed 274 feet from 144 patients who underwent HV corrective surgery at Hasharon Hospital, Israel (2014–2024). Using custom Python-based software, we annotated 22 anatomical landmarks on preoperative, weight-bearing lateral radiographs (3 plantar fat pads and 19 plantar bony points). For each fat pad, 19 Distance features were generated (total 57), comprising 19 pairwise standardised distances. Associations between these distances and standard HV angles (HVA, IMA, DMAA, HIA) were assessed using Pearson and Spearman correlations, A subgroup analysis was carried out to compare patients aged below and above 40 years, as well as between male and female patients.

Results

In the full cohort, no distance feature correlated with standard HV angles at the prespecified threshold ( \(\:\left|r\right|\) or \(\:\left|\rho\:\right|\ge\:0.25\) , two-sided \(\:p<0.05\) ). Stratified analyses revealed subgroup-specific patterns: females showed three significant relationships (mainly involving the calcaneal fat pad), whereas males showed 29 predominantly negative forefoot–hindfoot correlations (e.g., base of 5th metatarsal fat pad \(\:\to\:\) calcaneal fat pad vs. HIA: \(\:r=-0.44\) , \(\:\rho\:=-0.39\) , both \(\:p<0.01\) ). The \(\:<40\) y group exhibited six significant features (including sesamoid-based positives), while the \(\:\ge\:40\) y group showed two first-ray–focused associations. Several effects were stronger on Spearman than Pearson, consistent with nonlinearity, and many between-group differences were significant by Fisher’s \(\:r\) -to- \(\:z\) ( \(\:p<0.05\) ). Progressive Distance Mapping (PDM) summarized these effects into composite, radiograph-overlaid maps.

Conclusions

Progressive Distance Mapping (PDM) may suggest subgroup-dependent, progressive associations between plantar fat–pad–anchored distance geometry and hallux valgus (HV) severity. Despite no universal cohort-level correlations, PDM identifies four distinct morphologic subtypes within each subgroup (stratified by age and sex), this may suggest differing pathogenesis and patterns of plantar fat-pad involvement. These subtype-specific signatures are often nonlinear;