Clinical Outcomes Measures for scKAFO

James A. Haley VA HospitalHSR&D/RR&D Center of Excellence: Maximizing

Rehabilitation OutcomesTampa, FL9/30/2010

James A. Haley VA HospitalHSR&D/RR&D Center of Excellence: Maximizing

Rehabilitation OutcomesTampa, FL9/30/2010

Clinical Outcomes Measures for scKAFO

Sam L Phillips, PhD, CP FAAOPHealth Scientist

Tampa VA Center of Excellence:Maximizing Rehabilitation

Outcomes

• Awarded COE 2009– Expansion of Patient Safety Center of Inquiry

and Falls Clinic– August 2009 to lead study of rehabilitation

outcomes in Prosthetics, Orthotics, and amputee care

Tampa VA Center of Excellence:Maximizing Rehabilitation

Outcomes

• Clinical Staff:– Regional Amputation Center Clinic– Falls Clinic

• Engineers– Biomechanics Computer Science– Ergonomics

• Health Economists• Biostatisticians• Health Care System Researchers• Database Specialists• Affiliated with University of South Florida

The genesis of a research agenda

Tampa has a SCI injury Center of Excellence:“How can we improve outcomes with

KAFOs”“Do Stance Control KAFO’s Work?”

Literature• There is a small, but significant energy

cost savings when using a scKAFO5

Stance Control Knee Orthoses

• Knee Joint is locked in stance

• Free in swing• Stumble recovery

• May be actuated: Mechanically

• Force sensor• Inclinometer

On Left: SCOKJ From Horton Orthotics

Reported Benefits to scKAFO usage

Prevents Damage to ligaments from long term non-use

• Increased Walking Speed• Reduced falls• Improved muscle control

Standard Orthotic Knee Joints

• Drop Lock• Locks in place upon

standing in full extension• Walk with Fully Extended

Knee

• Offset Joint• Flexes during swing• Is stable when ground

reaction force is anterior to knee joint center

Drop Lock1 Offset Joint2

Problems with Knee Ankle Foot Orthoses

• Offset free swing knee joints • Stable when the axis of the joint is posterior to the

ground reaction force. • When the ground reaction force is posterior to the

knee joint, the knee joint can buckle.

• Locked Knee Joints• Very stable• Require Compensatory Motions• Difficult to recover from a stumble

Problems cont.

• Walking with KAFO increases energy expenditure

• Lead to slower walking speeds• Rejection rates among traditional KAFO

users are between 22 - 80%.1

Examples of difficult situations

• Obstacles• Uneven Terrain• Steps• Ramps• Crossing Street

Clinical evidence

• 5 patients have been fit with scKAFOs at the James A. Haley VA

• 2 rejected device• 3 accepted device• 1 was extremely successful, eventually

graduating out of KAFO use• Reviewing charts and interviewing

providers was inconclusive

Database Study

• scKAFO code L2005 was added in 1/1/2005

• Hypothesis: scKAFO utilization over time should fit the technology adoption curve

• Nationwide Data VA data was pulled from the NPPD Database

scKAFO Utilization from 2007-2010

• Approximate 8% of total KAFOs provided

• Utilization has not increased since 2008

0

10

20

30

40

50

60

70

80

90

2007 2008 2009 2010

0%

2%

4%

6%

8%

10%

12%

scKAFO

%scKafo

Database Study

• Where are we on the curve?

• Review for regional differences in use and adoption comparison of utilization for unilateral and bilateral use – No identifiable trends

were seen

MethodsNext Steps

• Capture Cohort of KAFO users in NPPD• Track through DSS

– Understand the Population Mix– Track total healthcare costs– Track adverse events

Functional Balance Measures

Considerations for selections• Ease of Clinical Implementation• Likely to be affected by Knee motionFour Measures:

– Maximum Step Length– Timed Up and Go– Four Square Step Test– Dynamic Gait Index

Maximum Step Length

Requirements:• Tape Measure• Masking TapeMeasure: Length (cm)Repeat: 3 timesTake maximum value*Must return behind

starting line

8 Ft Timed Up and Go

Requirements:• Chair with Arms• Cone• StopwatchMeasure: Time(s)Repeat: 2 times

Four Square Step Test

Requirements:• Four Canes• StopwatchMeasure: Time (s)Repeat: 2 times

Dynamic Gait Index

• Requirements:• Two Cones• One object to step over

• Eight Subtests

• Graded on 4pt scale (0-3)• Subjective Grading

• Walking Normal• Walk Fast –Slow• Walk w/ Pivot Turn• Walk while turning head

left/right• Walk while turning head

up/down• Walk over object• Walk around Object• Up and Down Steps

Methods

• Controls Functional Balance– Two Stance Control KAFO devices were

fabricated for healthy adults.– Subjects were tested in four conditions

• Unbraced • Free Knee • Stance Control • Locked Knee

Motion Analysis

• Markers for– Pelvic Motion– Markers on Both KAFO

and limb– Shoes

• Scanned with Biosculptor Scorpion CAD

Motion Analysis - Measures

• Kinematics• Kinetics• Compensatory

Motions– Hip Hiking (pelvic

obliquity)– Vaulting (contralateral

plantarflexion)– Circumduction

• Minimum Toe Clearance

Preliminary Results - Controls

• Timed up & go and Four Square Step Test show increased times for Locked knee compared to free knee

• Maximum Step Length shows decreased length for locked knee compared to free conditions

• DGI has ability to use stairs step over step

Veterans

• KAFO users• Repeated measures testing, Current

device, Baseline at delivery and three month follow up– Braced and Unbraced– OPUS survey– Telephone Follow-up changes and use– Activity Monitors (compliance)– Interviews

Summary

• Minimum Step Length, Timed Up and Go, and Four Square Step Test may be sensitive to changes in Orthotic Knee Joint Function– More work is needed

References

1. Fillaur Corporation www.fillaur.com2. Becker Orthopedic www.beckerortho.com3. Basford, Jeffrey R, and Sandra J Johnson.

“Form may be as important as function in orthotic acceptance: a case report.” Archives of Physical Medicine and Rehabilitation 83, no. 3 (March 2002): 433-435.

4. Vinci, P, and P Gargiulo. “Poor compliance with ankle-foot-orthoses in Charcot-Marie-Tooth disease.” European Journal of Physical and Rehabilitation Medicine 44, no. 1 (March 2008): 27-31.

5. Fatone, Stefania. “A Review of the Literature Pertaining to KAFOs and HKAFOs for Ambulation Journal of Prosthetics and Orthotics 18, no. 3S (2006): 137-168.

Thank You