601 - The Impact of Pelvic Incidence on Hip Performance during Gait Phases:...

General Session: Pediatric Spine

Presented by: J. Varghese - View Audio/Video Presentation (Members Only)

Author(s):

A. Patel(1), J. Varghese(1,2), H. Bao(1), A. Assi(3), E. Godwin(2), L. Day(2), B. Diebo(1), V. Lafage(1), C. Paulino(1)

(1) Hospital for Special Surgery, Spine Service, New York, NY, United States
(2) SUNY Downstate Medical Center, Department of Orthopaedic Surgery, Brooklyn, NY, United States
(3) University of Saint-Joseph, Beirut, Lebanon

Abstract

Introduction: Pelvic morphology, assessed by pelvic incidence (PI), is a cornerstone of sagittal alignment analysis. However, the extent to which pelvic morphology drives dynamic behavior of the hip during gait remains unclear.

Purpose: To investigate the impact of pelvic incidence on hip range of motion during gait in adolescent idiopathic scoliosis (AIS) patients.

Methods: Prior to surgical treatment, AIS patients underwent gait assessment and full spine radiographs. Gait analysis was performed in a 6-DOF motion analysis laboratory at a sampling frequency of 100 Hz. Thirty-four reflective markers were placed on each patient who then underwent straight-line walking trials. Patients were grouped based on pelvic incidence (Low PI: < 40th percentile of overall mean PI; High PI: > 60th percentile). Groups were matched by global coronal alignment (C7PL, distance between C7 plumbline and sacrum). Demographics, radiographic and gait parameters were compared between PI groups.

Results: 18 patients included (Low PI: mean 43.1°, High PI: mean 60.2°, 9 pts in each). Groups had similar age (13.8-16.5yo), gender (66% female) and BMI (22.1 vs. 25.8). High PI had a greater PT (11.6 vs. 1.7°) and PI-LL (-1.4 vs. -17.8°), all p< 0.05. Absolute coronal curve magnitude, pelvic obliquity, and leg lengths were similar between the groups. Overall, High PI had a greater range of pelvic motion in the sagittal plane (4.5 vs. 3.6°) and the frontal plane (9.4 vs. 5.6°), all p< 0.05. Analysis of the hip joint revealed that High PI had a greater flexion-extension range of motion (16.5 vs. 10.8°), less maximum hip extension during stance (-4 vs. -10.2°), greater flexion at initial contact (33 vs. 26.7°), greater hip abduction/adduction range of motion during overall gait cycle (14 vs. 10.1°), and greater hip abduction during swing (-7.8 vs. -2.1), all p< 0.05.

Conclusions: In addition to its substantial impact on the regulation of sagittal postural alignment, pelvic incidence seems to play a role in the hip range of motion during gait cycles. Though further work is needed, this may suggest the possibility of a more personalized analysis of gait patterns based on pelvic morphology.