LEG LENGTH DISCREPANCY IN ADOLESCENT IDIOPATHIC SCOLIOSIS

EDUARDO MOREIRA PINTO,ALFREDO MENDES DE CASTRO,SILVA MARCOS,JOSÉ MIRADOURO,ARTUR TEIXEIRA,JORGE ALVES,ANTÓNIO MIRANDA

doi:10.1590/s1808-185120191803208752

Abstract

ABSTRACT Objective The objective of this study is to evaluate leg length discrepancy in adolescent idiopathic scoliosis. Methods A retrospective study of 80 subjects with adolescent idiopathic scoliosis (AIS) was conducted. The inclusion criteria were patients aged 10 to 18 years old with posteroanterior (PA) and lateral full-length radiographs. The exclusion criteria were patients subjected to surgery or orthotic treatment, those with other spinal disease, and those with poor quality x-rays. The parameters evaluated were: age, sex, Risser stage (RS), triradiate cartilage (TC), scoliotic curvatures, differentiated according to Lenke classification, sagittal (SB) and coronal balance (CB), and leg length discrepancy, which was assessed through the difference between the femoral heads (LLD) and through the assessment of pelvic obliquity (PO). Results The majority of patients with AIS demonstrated a mild LLD (<1 cm). The mean LLD was significantly different (p<0.01) between the scoliotic population with a main thoracolumbar curvature and those with a main lumbar curvature. When there was an LLD, it was the left limb that was shortened in most cases. The side of the longer lower limb had a direct influence on the CB (p=0.052). Conclusions This study demonstrates that in an AIS population with small LLD values, the extent of the shortening has a stronger impact on coronal balance and location than on the dimension of the main scoliotic curvature. These results demonstrate the importance of a more in-depth study on the effects of LLD <1 cm in the development of AIS and coronal imbalance. Level of evidence IV; Case Series.

Highlights

Introduction3 to 15% of population has a limb length discrepancy (LLD) of around 1 cm; in 95% of cases, the causes are unknown.[1,2]LLD causes pelvic obliquity in the frontal plane 2 and leads to posture deformation, gait asymmetry, low back pain, discopathy, gonarthrosis, coxarthrosis and hip flexion contracture in the longer extremity or ankle joint contracture in the equinal position in the shorter extremity.[3,4,5,6] In these cases, the LLD is due to asymmetrical load on the lower extremities.[7,8,9,10] Measurement of LLD, and the patient’s age, are the most important factors in the management of this disease.[11]
The posture implemented in the radiographic acquisition mirrors that advocated by the Scoliosis Research Society (SRS) i.e. plain full-length radiographs performed in the orthostatic position, with the anterior superior iliac spine parallel to the cassette and the beam aimed at T10
The initial analysis of this study effectively proves a female majority in the domain of adolescent idiopathic scoliosis

Summary

Introduction

3 to 15% of population has a limb length discrepancy (LLD) of around 1 cm; in 95% of cases, the causes are unknown.[1,2]LLD causes pelvic obliquity in the frontal plane 2 and leads to posture deformation, gait asymmetry, low back pain, discopathy, gonarthrosis, coxarthrosis and hip flexion contracture in the longer extremity or ankle joint contracture in the equinal position in the shorter extremity.[3,4,5,6] In these cases, the LLD is due to asymmetrical load on the lower extremities.[7,8,9,10] Measurement of LLD, and the patient’s age, are the most important factors in the management of this disease.[11]. The progression of the curve and the effectiveness of the treatment are determined by the patient’s age and sex, the magnitude and pattern of the curvature, and skeletal maturity.[13,14,15]

Methods

Results

Discussion

Conclusion