Lower Limb Length Discrepancy (LLD) in Children
Conditions
Keywords
EOS imaging, Biomechanics, Lower limb length discrepancy (LLD), Pediatric orthopedics, Force platform, limb length
Brief summary
Lower limb length discrepancy (LLD) is a frequent condition in pediatric orthopedics. Even moderate discrepancies can induce pelvic obliquity and compensatory scoliosis, modifying the distribution of joint loads at the hips and lumbar spine. These biomechanical imbalances are suspected to contribute to early degenerative conditions such as osteoarthritis or chronic low back pain. The aim of this study is to quantify the biomechanical impact of LLD in children aged 10 to 15 years, using a combination of low dose biplanar EOS imaging (EOS Imaging System) and synchronized ground reaction force (GRF) measurements from integrated force platforms. These data will be used in musculoskeletal models developed in collaboration with the Biomechanics and Impact Mechanics Laboratory (LBMC, Laboratoire de Biomécanique et Mécanique des Chocs), enabling the estimation of hip joint and lumbar intervertebral disc loads. This is the first pediatric study integrating EOS imaging, force platforms, and personalized musculoskeletal modeling to explore the mechanical consequences of LLD. The findings are expected to improve clinical reasoning and guide early therapeutic strategies.
Detailed description
Lower limb length discrepancy (LLD) is a frequent condition in pediatric orthopedics. Even moderate discrepancies can induce pelvic obliquity and compensatory scoliosis, modifying the distribution of joint loads at the hips and lumbar spine. These biomechanical imbalances are suspected to contribute to early degenerative conditions such as osteoarthritis or chronic low back pain. The aim of this study is to quantify the biomechanical impact of LLD in children aged 10 to 15 years, using a combination of low dose biplanar EOS imaging (EOS Imaging System) and synchronized ground reaction force (GRF) measurements from integrated force platforms. These data will be used in musculoskeletal models developed in collaboration with the Biomechanics and Impact Mechanics Laboratory (LBMC, Laboratoire de Biomécanique et Mécanique des Chocs), enabling the estimation of hip joint and lumbar intervertebral disc loads. A temporary orthopedic compensation (shoe lift) will also be tested to assess its immediate biomechanical effect. Participants will be evaluated at baseline (two EOS acquisitions: with and without compensation) and at 2 years (without compensation). This is the first pediatric study integrating EOS imaging, force platforms, and personalized musculoskeletal modeling to explore the mechanical consequences of LLD. The findings are expected to improve clinical reasoning and guide early therapeutic strategies.
Interventions
RADIATIONEOS Imaging System
Low-dose biplanar radiographs of the whole body in standing position (EOS Imaging System). At baseline, two EOS acquisitions will be performed in static standing position : one without compensation (natural position) and one with temporary orthopedic compensation (shoe lift under the shorter limb). At 24 months, one EOS acquisition will be performed without compensation. Each acquisition lasts a few seconds, with radiation exposure 5 to 10 times lower than conventional radiographs.
DEVICEForce Platform (Bertec®, integrated into EOS cabin)
Ground reaction force (GRF) measurements obtained from a force platform integrated in the EOS cabin. The platform records weight distribution and center of pressure during static standing posture. Measurements are fully synchronized with EOS acquisitions, without additional time or discomfort for participants. At baseline, GRF measurements will be collected in two conditions (with and without orthopedic compensation). At 24 months, GRF measurements will be collected in the non-compensated condition.
Sponsors
Hospices Civils de Lyon
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
10 Years to 15 Years
Healthy volunteers
No
Inclusion criteria
* Children aged 10-15 years * Anatomical LLD \> 5 mm, clinically measured * EOS imaging indicated by the pediatric orthopedic surgeon in routine care * Ability to stand still for 30 seconds without assistance * Covered by social security * Parental consent and non-opposition obtained
Exclusion criteria
* \- Functional or postural LLD without true anatomical discrepancy * History of major pelvic or spinal surgery * Severe neurological or orthopedic condition preventing standing (e.g. cerebral palsy, progressive myopathy) * Fixed equinus deformity preventing plantar support * Major lower limb deformity (severe genu varum/valgum) * Contraindication or inability to undergo EOS imaging
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Asymmetry of Hip Joint Contact Forces (%) in Static Standing | At baseline (Day 0, without compensation) | Hip joint contact force asymmetry index (%): calculated as AI (%) = 100 × (F\_long - F\_short) / \[(F\_long + F\_short)/2\], where F\_long and F\_short are side-specific resultant hip joint contact forces (estimated by musculoskeletal modeling from EOS imaging and ground reaction force data). Units: percent (%).Higher values indicate greater asymmetry. |
Countries
France
Contacts
CONTACTThierry HAUMONT, MD, PhD
CONTACTDimitri HERRERA-NATIVI
PRINCIPAL_INVESTIGATORThierry HAUMONT, MD
Hospices Civils de Lyon
Outcome results
None listed