VIMSVIMS LabsLabs• Functional anatomyFunctional anatomy• Muscle & joint mechanicsMuscle & joint mechanics• Bone/cement/stem stressesBone/cement/stem stresses• EF adjustability & rigidity EF adjustability & rigidity • Implant design & testingImplant design & testing• Operative planningOperative planning

Biomechanics of Biomechanics of TOSTOS

• Neurogenic thoracic outlet syndrome Neurogenic thoracic outlet syndrome (nTOS) is controversial(nTOS) is controversial

• TO Area (TOA) has yet to be defined TO Area (TOA) has yet to be defined and measured in 3Dand measured in 3D

• Objectives:Objectives:- DEFINE TOA in 3D- DEFINE TOA in 3D- VISUALIZE and QUANTIFY - VISUALIZE and QUANTIFY TOA change in 3 TOA change in 3 provocative maneuversprovocative maneuvers

(Dr. Kato of (Dr. Kato of Iwate Uni.)Iwate Uni.)

CostoclavicuCostoclavicular Spacelar Space

• Between first rib, Between first rib, clavicle(subclavius), clavicle(subclavius), first rib and scapulafirst rib and scapula

• Compression of Compression of subclavian artery, vein subclavian artery, vein and brachial plexusand brachial plexus

Pectoralis Pectoralis Minor SpaceMinor Space

InterscalenInterscalene Trianglee Triangle

Costoclavicular Costoclavicular SpaceSpace

Sternum

1st Rib

2nd Rib

Clavicle

Scapula

Wright’s TestWright’s TestLoss of Pulse with Loss of Pulse with

Inspiration Inspiration

Military Brace or Military Brace or Eden TestEden Test

Drooping testDrooping test

Provocative maneuver for TOSProvocative maneuver for TOS

Thoracic Outlet Thoracic Outlet SyndromeSyndromeDrooping TestDrooping Test Eden TestEden Test

Wright TestWright Test

2D DEA of Carpal Contact Stress2D DEA of Carpal Contact Stress

Dr. Iwasaki, Hokaido Uni.Dr. Iwasaki, Hokaido Uni.

Radial-Ulnar-Carpal & Radial-Ulnar-Carpal & Intercarpal Contact ForceIntercarpal Contact Force

InvolvedInvolved NormNormalal

Kienböck Disease Kienböck Disease 3B3B

Carpal Carpal Contact Contact Stress Stress

using DEA using DEA SimulationSimulation

VIMS -VIMS - ModelModel The carpal skeletal complexThe carpal skeletal complex

Dr. Iwasaki & Dr. GendaDr. Iwasaki & Dr. Genda

3D Contact Area for DEA3D Contact Area for DEARadioulnar/Carpal; Carpal/MetacarpatRadioulnar/Carpal; Carpal/Metacarpat

Wrist LigamentsWrist Ligaments

RSRLTFC

Palmar

A. B.

C. D. 0

5

10

MPa

3D Contact 3D Contact Area/Stress of Distal Area/Stress of Distal

Radius & UlnaRadius & Ulna

IntactIntact STTSTT

SSCC

CCHH

Validation of Carpal Validation of Carpal Contact Area & Contact Area &

PressurePressure

Prof. Hara, Niigata U; Dr. Ide, Yamanashi UProf. Hara, Niigata U; Dr. Ide, Yamanashi U

Fracture reduction & Fracture reduction & planning usingplanning using VIMSVIMS

Dr. Kim of Korea, Dr. Kim of Korea, J. Lim J. Lim & R. Armiger& R. Armiger

Fracture reduction, joint Fracture reduction, joint contact & ligament contact & ligament stress under EFstress under EF

Glenohumeral & ScapulothoracicGlenohumeral & Scapulothoracic Motion RhythmMotion Rhythm

0

5

10

15

20

25

30

35

40

45

50

55

0 30 60 90 120 150

HUMERAL ELEVATION (degrees)

SC

AP

UL

AR

EL

EV

AT

ION

(d

eg

ree

s) CORONAL PLANE

SAGITTAL PLANE

Sagittal & Coronal Plane ElevationSagittal & Coronal Plane Elevation

M. Fung & Dr. KatoM. Fung & Dr. Kato

DEA DEA (Discrete Element Analysis)(Discrete Element Analysis)

• Rigid body Rigid body spring model spring model

• Spring deformity Spring deformity determines joint determines joint contact pressure contact pressure and ligaments and ligaments tensiontension

Concept Concept

DEADEA Model DevelopmentModel Development