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Updated: Jul 7, 2026
Method and Instrumented Fixture for Femoral Fracture Testing in a Sideways Fall-on-the-Hip Position
Published on: August 17, 2017
Development of the D-FLLIP classification for ipsilateral floating hip and knee injuries
M A Altamirano-Cruz1, F Hernández-Aceves2, S Q Rodríguez-Lara3
1UMAE Centro Médico Nacional de Occidente IMSS, Encargado del Módulo de Politrauma, Pelvis y Acetábulo, Guadalajara, Jalisco, Mexico.
Introduction:
Ipsilateral "floating lower limb" (FLL) -coexisting pelvic/acetabular, femoral, and tibial fractures- presents rare, high-energy trauma with complex limb-threat physiology. A standardized diagnostic framework could improve early triage and operative sequencing.
Objective:
To develop and preliminarily evaluate the diagnostic floating lower limb ipsilateral protocol (D-FLLIP) as an ordinal severity classification and early decision-support tool for FLL.
Methods:
Retrospective, single-center case series at a tertiary trauma referral hospital (January 2018 / December 2023); n=28 consecutive patients meeting FLL criteria. Study design characteristics: retrospective, informal, single-center, consecutive, exposure-based sampling (clinical); level of evidence IV. Patients were graded I-V with D-FLLIP from itemized domains (pelvis, femur, tibia, and soft-tissue/high-risk features). Primary analyses used Kruskal-Wallis and Fisher's exact/χ2 to compare variables across grades. An exploratory univariable logistic regression assessed discrimination of an acute-complication composite (ICU stay >0 days, amputation, early wound infection <30 d, or significant vascular injury) with ROC/AUC estimation. Ethics approval: R-2024-1301-106; Declaration of Helsinki compliant.
Results:
Grade distribution: I=7 (25.0%), II=11 (39.3%), III=6 (21.4%), IV=2 (7.1%), V=2 (7.1%). Across grades, ICU length of stay and peak lactate increased stepwise (P=.0357 and P=.0128); MESS differed by grade (p=0.0264). Vascular injury and amputation were more frequent at higher grades (P≤.01), whereas early wound infection was not significant (P=.0832). The acute-complication composite rose with grade but was not statistically significant (P=.5505). Discrimination was moderate (AUC≈0.69); a pragmatic threshold grade ≥3 yielded sensitivity 0.45 and specificity 0.875.
Conclusions:
D-FLLIP provides a pragmatic, standardized early-severity framework for FLL, aligning with clinical gradients in ICU use, metabolic derangement, and limb-threat events. Given small, unbalanced strata -especially grades IV-V- findings are exploratory/hypothesis-generating. Prospective multicenter validation, interobserver reliability studies, and cut-off calibration are warranted to refine clinical implementation.
