In Vivo Quantification of Hip Arthrokinematics during Dynamic Weight-bearing Activities using Dual Fluoroscopy

Summary

Dual fluoroscopy accurately captures in vivo dynamic motion of human joints, which can be visualized relative to reconstructed anatomy (e.g., arthrokinematics). Herein, a detailed protocol to quantify hip arthrokinematics during weight-bearing activities of daily living is presented, including the integration of dual fluoroscopy with traditional skin marker motion capture.

Abstract

Several hip pathologies have been attributed to abnormal morphology with an underlying assumption of aberrant biomechanics. However, structure-function relationships at the joint level remain challenging to quantify due to difficulties in accurately measuring dynamic joint motion. The soft tissue artifact errors inherent in optical skin marker motion capture are exacerbated by the depth of the hip joint within the body and the large mass of soft tissue surrounding the joint. Thus, the complex relationship between bone shape and hip joint kinematics is more difficult to study accurately than in other joints. Herein, a protocol incorporating computed tomography (CT) arthrography, three-dimensional (3D) reconstruction of volumetric images, dual fluoroscopy, and optical motion capture to accurately measure the dynamic motion of the hip joint is presented. The technical and clinical studies that have applied dual fluoroscopy to study form-function relationships of the hip using this protocol are summarized, and the specific steps and future considerations for data acquisition, processing, and analysis are described.

Introduction

The number of total hip arthroplasty (THA) procedures performed on adults aged 45-64 years suffering from hip osteoarthritis (OA) more than doubled between 2000 and 2010¹. Based on the increases in THA procedures from 2000 to 2014, a recent study predicted that the overall number of yearly procedures may triple over the next twenty years². These large increases in THA procedures are alarming considering that current treatment costs exceed $18 billion annually in the United States alone³.

Developmental dysplasia of the hip (DDH) and femoroacetabular impingement syndrome ....

Protocol

Procedures outlined in this protocol were approved by the University of Utah Institutional Review Board.

1. CT arthrogram imaging

1. Arthrogram¹⁸
   1. Schedule a trained musculoskeletal radiologist to perform the arthrogram directly prior to the scheduled CT imaging.
   2. Position the participant on the table with the hip of interest in the field of view of a clinical fluoroscope. Place sandbags on either side of the ankle to prevent rotation of th.......

Discussion

Dual fluoroscopy is a powerful tool for the investigation of in vivo kinematics, especially for the hip, which is difficult to accurately measure using traditional optical motion capture. However, fluoroscopy equipment is specialized, wherein a unique system setup may be required when imaging other joints of the human body. For example, several modifications were made to the mounting of the image intensifiers, positioning of the system, and settings of the beam energy in the application of dual fluoroscopy to th.......

Materials

Name	Company	Catalog Number	Comments
Amira Software	ThermoFisher Scientific	Version 6.0
Calibration Cube		Custom	36 steel beads (3 mm diameter, spacing 6.35 cm, uncertainty 0.0036 mm)
Calibration Wand	Vicon	Active Wand
CT Scanner	Siemens AG	SOMATOM Definition 128 CT
Distortion Correction Grid		Custom	Acrylic plate with a grid of steel beads spaced 10 mm and 31 beads across the diameter (2 mm diameter)
Dynamic Calibration Plate		Custom	Acrylic plate with 3 steel beads spaced 30 mm (2 mm diameter, uncertainty 0.0013 mm)
Emitter (2)	Varian Interay; remanufactured by Radiological Imaging Services	Housing B-100/Tube A-142
Epinephrine	Hospira	Injection, USP 10 mg/mL
FEBioStudio Software	FEBio.org	Version 1.3	Mesh processing and kinematic visualization
Graphical Processing Unit	Nvidia	Tesla
Hare Traction Splint	DynaMed	Trac-III, Model No. 95201
High-speed Camera (2)	Vision Research, Inc.	Phantom Micro 3
Image Intensifier (2)	Dunlee, Inc.; remanufactured by Radiological Imaging Services	T12964P/S
Iohexol injection	GE Healthcare	Omnipaque 240 mgI/mL	517.7 mg iohexol, 1.21 mg tromethamine, 0.1 mg edetate calcium disodium per mL
ImageJ	National Institutes of Health and Laboratory for Optical and Computational Instrumentation
Lidocaine HCl	Hospira	Injection, USP 10 mg/mL
Laser and Mirror Alignment System		Custom	Three lasers adhered to acrylic plate that attaches to emitter, mirror attaches to face of image intensifier
Markless Tracking Workbench	Henry Ford Hospital, Custom Software	Custom
MATLAB Software	Mathworks, Inc.	Version R2017b
Motion Capture Camera (10)	Vicon	Vantage
Nexus Software	Vicon	Version 2.8	Motion capture
Phantom Camera Control (PCC) Software	Vision Research, Inc.	Version 1.3
Pre-tape Spray Glue	Mueller Sport Care	Tuffner
Retroreflective Spherical Skin Markers			14 mm
Split Belt Fully Instrumented Treadmill	Bertec Corporation	Custom
Visual3D Software	C-Motion Inc.	Version 6.01	Kinematic processing