A proposed three‑dimensional anatomical definition and morphometric quantification of the lateral femoral wall: a reliable CT‑based measurement system validated across two software platforms.

purposeThe lateral femoral wall serves as a critical determinant of intertrochanteric fracture stability, internal fixation strategy, and postoperative clinical outcomes, and has emerged as one of the core research focuses in orthopedic trauma. However, no consensus exists on the anatomical boundaries, standardized measurement criteria, and morphometric parameter system of the lateral femoral wall.

methodsConsecutive individuals aged 18 years and above who had full-length or upper-half CT scans of the femur were included from January 2015 to June 2024. Complete three‑dimensional boundaries and a comprehensive measurement system for the lateral femoral wall were established. All morphometric parameters were independently quantified using two software platforms (Mimics and SuperImage). Statistical analyses were performed to assess inter‑software consistency, intra‑ and inter‑observer reliability, sex‑based morphological differences, and correlations between lateral wall morphology and age as well as body height.

resultsA total of 171 participants were enrolled in this study, consisting of 91 females and 80 males. No statistically significant inter-software differences were detected for any of the morphometric parameters (all P > 0.05). Inter-software measurements showed significant positive correlations (Pearson r = 0.740-0.986, all P < 0.001), and no systematic bias via Bland-Altman analyses. Intra- and inter-observer intraclass correlation coefficients (ICCs) revealed substantial to almost perfect agreement for the central coronal curvature diameter (0.811-0.836, 95% CIs 0.764-0.876), while all other morphometric parameters achieved almost perfect agreement, with intra-observer ICCs of 0.858-0.993 and inter-observer ICCs of 0.841-0.984. Significant sexual dimorphisms were observed: males had greater lateral wall height, segmental width and cortical thickness at most planes (all P < 0.05). Body height was the dominant positive determinant of most morphological parameters (ρ = 0.194 to 0.909, all P < 0.05), whereas age exerted only mild-to-moderate negative effects on segmental width and thickness (ρ = - 0.578 to - 0.174, all P < 0.05). Significant positive width-thickness correlations existed at all transverse planes (all P < 0.001). Notably, the central coronal curvature diameter showed no sex-related difference (P = 0.216) and remained stable across age and height subgroups.

conclusionThis study proposed a reliable 3D measurement system for the lateral femoral wall with complete anatomical boundary definition. The central coronal curvature, independent of sex, age and height, can act as a universal baseline contour for implant design. In contrast, its overall dimensions differ across sex and height, supporting patient‑specific implant sizing.