Association of Children's Prosthetic-Orthotic Clinics…

                 Association of Children's Prosthetic-Orthotic Clinics
                       2006 Annual Meeting, May 17-20, 2006
                Hyatt Regency at Capitol Park, Sacramento, California
                                   Thursday, May 18, 2006

Scientific Paper Session I ­ Lower Extremity
7:30 ­ 9:05 am

7:30 am / Paper #1
      COMPARISON OF TEMPORAL-SPATIAL GAIT PARAMETERS USING AN
  ELECTRONIC WALKWAY SYSTEM FOR CHILDREN WITH CEREBRAL PALSY
   AMBULATING WITH DYNAMIC ANKLE-FOOT ORTHOSIS OR AMBULATING
                                        BAREFOOT
       Valerie C Wondra, PT; Ken Pitetti, PhD, Wichita State University, Wichita, Kansas

Background: Previous studies have compared temporal and spatial gait characteristics in
children with cerebral palsy (CP) with and without ankle-foot orthosis using kinematics 1,2,3.
These studies have reported differences in gait parameters when comparing ambulation with and
without an ankle-foot orthosis (AFO). However, few studies have reported these gait parameters
in children with CP using an electronic walkway system.

Purpose: To compare temporal and spatial gait parameters of children with CP during
ambulation with ankle-foot orthosis (DAFO; Cascade DAFOTM, #3 and #4) with shoes and
barefoot (BF).

Participants: 12 children (2-15 yrs, 6.8+4.1 yrs; 2 males, 10 females) with spastic CP (10
diplegic, 2 hemiplegic) participated in this study.

Method: All participants walked either independently without an assistive device (n=4) or
independently with ambulatory devices (1 quad canes, 6 reverse walkers, 1 forward walker) at
their preferred speed in the middle of the 12-foot long electronic walkway (GAITRite®
Walkway System). Three trials were performed for each condition (DAFO, BF) and the mean of
the three trials was compared for each of the following gait parameters: cadence, cycle time,
stride length, step length, and gait velocity.
Results: No significant differences were seen between DAFO and BF for cadence (steps/min)
and cycle time (sec). However, significant differences (p BF
Conclusion: Results of this study suggest that stride length, step length, and gait velocity are
significantly increased when wearing DAFO versus BF ambulation. When compared to studies
using kinematics, our results are similar for stride and step length 1,2,3 but differ in cadence 1,2 and
gait velocity 1,2,3. That is, the present study did not demonstrate differences in cadence, yet the
DAFO did improve walking speed. However, discrepancies between studies could be due to
differences in participant disability levels (i.e., hemiplegic vs. diplegic, walking with and without
an assistive device) and age.

Clinical Relevance: Determining the functional effect (gait parameters of stride length and
velocity) of DAFO's on children with ambulation deviations will add to the information that is
currently reported and assist therapists and practitioners with determining the benefit of
prescribing and providing DAFO's on those with gait deviations.

1. Radtka et al. (1997)         2. Romkes et al. (2002)         3. Buckon et al. (2004)

7:40 am / Paper #2
    RESIDUAL LIMB END-BEARING PRESSURES IN CHILDREN WITH SYME'S
                      AMPUTATIONS: PRELIMINARY RESULTS
                Janet Walker, MD; Donna Oeffinger, PhD; Hank White, MSPT
                       Shriners Hospital for Children, Lexington, KY

Introduction: Techniques to preserve the heel pad during lower limb amputation were designed
to allow end bearing on the specialized tissues of the heel pad. Studies of adult amputees with
Syme's or Boyd amputations, however, have suggested that few patients walk on the end of their
residual limbs without their prosthesis and that the end bearing pressures in their prostheses are
low [1]. Children with Syme's or Boyd amputations will often walk without their prostheses and
frequently grow out of their prosthetic patellar tendon bar molds with few complaints of pain.
The purpose of this study was to measure the end bearing and patellar tendon pressures of
children with Syme's amputations in their prostheses and to compare those findings with those
previously reported for adults. Information obtained about pressures within a socket may
improve the clinical decision making process and improve the fit of the prosthesis for children
with Syme's/Boyd amputations.

Methods: IRB approval was obtained for this study. To date four children between the ages of 6
and 18 years with unilateral Syme's amputations were recruited from the hospital's Orthotic and
Prosthetic clinic. Pressure measurements in the prostheses were obtained during walking. 4x4cm
socket pressure sensors (Novel Inc) were placed on the patellar tendon region and the terminal
distal end of the residual limb. Data were collected from three trails for each subject. The means
of data from the three trials were calculated for each subject. Measurements were normalized to
body weight (BW) without the prosthesis. The means from each subject were averaged and data
between sensors compared for each of the study parameters using a t-test. Pressure
measurements were obtained with each subject walking on their residual limb across an EMED
pedobarograph.

Results: No differences between the patellar tendon and the distal end were found for contact
area, maximum force, contact time, instant of peak pressure, instant of maximum force, mean
force and mean area. Peak pressures at the distal end (10.84 N/cm2) and the patellar tendon
(12.83 N/cm2) were significantly different (p=0.02) from one another. These data show that the
patellar tendon receives a greater peak pressure than the distal end region. The mean maximum
pressures (average of the peak pressure over entire cycle) neared significance at p =.052 with the
distal end region mean of 6.86 N/cm2 and at the patellar tendon region mean 5.39 N/cm2. The
average maximum force obtained from walking on the residual limb was 127%BW (range 86-
174%BW).

Conclusions: The data from these 4 children with Syme's amputations shows that they do
weight bear at the distal end of the residual limb. These findings are different from those
previously stated in the literature on adults. The pressures at the distal end and at the patellar
tendon area are very similar to one another. The children were able to fully weight bear on their
residual limb as evidenced by full weight bearing on the residual limb when walking without
their prostheses.

Reference: 1Hornby, R., and Harris, R. (1975). JBJS, 57-A(3), 346-349.

Acknowledgments: Sarah Rogers, Wayne Cottle, Chris Burke & Eric Miller for their assistance
with the study. Funding provided by Kosair Charities Inc.

8:00 am / Paper #3
       OXYGEN CONSUMPTION IN CHILDREN WITH LOWER EXTREMITY
                 AMPUTATIONS DURING OVER GROUND WALKING
                              Kelly Jeans, MS; Lori Karol, MD
                   Texas Scottish Rite Hospital for Children, Dallas, Texas

Over the years, amputee gait has been well studied in adult populations. Researchers have found
that as the level of amputation ascends the leg, walking velocity declines, and oxygen
consumption demands are increased. Very few studies have studied the effect different levels of
amputation have on oxygen consumption in children. Herbert et al (1994) found that children
with below knee amputations had higher energy needs than children without amputation. The
current study was designed to compare amputee oxygen consumption across levels in children
between the age of seven and 19 during over ground walking (OG). This paper is a preliminary
report on Symes, trans-tibial (BK), and knee disarticulation (KD) amputees.

Thirty-two unilateral amputees between the ages of seven and 19 were enrolled in this IRB
approved study (24 boys and eight girls). Fifteen had Symes amputations, nine had BK
amputations, and eight had KD. All patients were asked to sit and rest for 5 minutes prior to the
walking test. After the rest period, subjects walked for ten minutes at a self selected speed around
a 40 meter walk-way. Oxygen consumption data was collected using the K4B2 oxygen analysis
telemetry unit (COSMED, Rome, Italy). Data was reduced over a one-minute steady-state
interval and averaged. Velocity was measured during the walk and recorded.
                        VO2     Velo-
Level     N   Age       Cost     city      HR
Symes     15 11.13     0.24     71.52    112.39
                       109%     102%     98%
BK        9    10.89   0.25     74.96    127.11
                       114%     107%     111%
KD        8    14.50   0.25     70.37    114.93
                       139%     96%      119%
Table 1- VO2 Cost= ml/kg/m; velocity= m/min; HR= beats/min. % age matched normal* values
given beneath absolute values for each group. (*Perry, 1992)

Oxygen consumption cost (VO2 cost), velocity and heart rate (HR) are reported in Table 1.
Significant differences were found in age between groups (BK being the youngest and KD being
the oldest); therefore each level was compared to published age-matched normals.

Findings show that compared to normal, HR and VO2 cost increase with level of amputation.
Velocity, however, is maintained. These children do not have to slow down due to energy
requirements and they can tolerate the increase in HR.

This study demonstrates that as the level of amputation ascends the leg, that although the energy
requirement increases, speed is maintained in children. Distal level should be preserved
whenever possible.

Perry: Gait Analysis- Normal and Pathological Function, SLACK Inc, 443-489, 1992.

Herbert, et al.: A Comparison of Oxygen Consumption During Walking Between Children With
and Without Below- Knee Amputations, Physical Therapy, 943-950, vol. 10, 1994.

8:30 am / Paper #5
 EFFECTIVE PREVENTION OF STUMP OVERGROWTH WITH AN AUTOLOGOUS
                             PROXIMAL FIBULAR GRAFT
             Anthony A Scaduto, MD; J Paul Ballesteros, MD; Hugh G Watts, MD
                Shriners Hospitals for Children, Los Angeles. Los Angeles, CA.

Purpose: Terminal overgrowth is a common problem in children with transosseus amputations.
Appositional bone growth produces an elongated tapered bone tip which prevents end-bearing
and proper fit of the prosthesis. It is characterized by distal swelling, tenderness, bursa
formation, and occasional skin perforation. The high incidence of recurrent overgrowth after
resection has been partially controlled by capping the bone with autogenous graft or a synthetic
device. We have modified stump capping as originally described by Marquardt to take
advantage of the ease in harvesting the ipsilateral fibula in a below-knee stump and eliminate the
need for screw or pin fixation of the cap. The purpose of this study was to determine the
effectiveness of this technique in preventing overgrowth and identify any donor site morbidity
associated with fibular head harvest.
Methods: Thirty-three limbs in 31 patients with trans-tibial amputations underwent stump
capping utilizing the ipsilateral proximal fibula. The distal tibia segment was resected, periosteal
flaps were elevated and the distal medullary canal was cleared with a curet. The proximal fibula
including the cartilagenous epiphysis was freed from its soft tissue attachments. The tibia was
then plugged with the reversed proximal. A snug fit was ensured by lightly impacting the graft
so the fibular diaphysis/metaphysis filled the canal of the distal tibia. The periosteal flaps were
then sutured to the periosteum or cartilage of the fibular head. We retrospectively studied all
patients with trans-tibial amputations who underwent this procedure between 1991 and 2002.
Average age at surgery was 8.1 years and mean follow-up was 7.1 years (2.0-13.7 years).
Twenty (61%) were acquired amputations and 13 (39%) were congenital. Eleven (33%) of the
stump cappings were done as part of the index surgery. Survival analysis was performed using
the Kaplan-Meier product-limit method.

Results: Failure defined as revision secondary to bony overgrowth occurred in 4 limbs (12%).
Skin problems unrelated to osseous overgrowth also required revision in one patient. The
estimated survival rate at six years was 92% (± 10%). The mean survival time was greater than
the time needed to reach skeletal maturity (>18 years). There were no infections, fractures, or
graft loosening. No graft harvest site complications were identified. All patients began
prosthetic fabrication 4-6 weeks postoperatively. One patient required a change in the type of
prosthesis used postoperatively.

Conclusion: The proximal fibula is an ideal osteocartilagenous graft to prevent tibial
overgrowth in children with below-knee amputations. It effectively controls overgrowth with a
low rate of morbidity.

Significance: Reported rates of revision for biologic and synthetic capping to prevent
overgrowth vary from 25-75%. In below-knee amputees, plugging the tibia with the ipsilateral
proximal fibula had a very low failure rate. Its advantages over other biologic or synthetic caps
include a well hidden scar, intrinsic graft stability, rapid incorporation, and a low rate of
infection/loosening.

8:50 am / Paper #6
      THE EFFECTIVENESS OF A PHYSICAL THERAPY INTERVENTION FOR
          CHILDREN WITH HYPOTONIA AND FLAT FOOT DYSFUNCTION
 Charmayne Ross, DPTSc; Fernando Villar, PhD; Grenith Zimmerman, PhD; Bonnie Forrester,
                               DPTSc; Everett Lohman, DPTSc
  Dept of Physical Therapy, School of Allied Health Professions, Loma Linda University, Loma
         Linda, CA; Dynamic Therapies, Inc 50 E Foothill Blvd, Suite 100, Arcadia, CA

Purpose: The purpose of this study was to determine the effectiveness of physical therapy using
Cascade soft orthotics and an exercise program for children with hypotonia and flatfeet.

Subjects: Thirty-seven children, aged 18 months to 5 years, who presented developmental
delays and hypotonia with flat foot dysfunction, participated in this study.
Methods & Materials: Three groups (control, orthotic, and orthotic-exercise), were studied.
The orthotic- exercise group practiced bilateral heel lifts besides wearing the orthoses. An arch
index was used to assess the width of the medial longitudinal arch (MLA) pre/post interventions.
Gait parameters (velocity, step-length, single-limb support, and cadence) were assessed four
times in a 6-month period using the GAITRiteTM system.

Analyses: A repeated-measures ANOVA for the dependent variables of arch index, velocity,
step length, single limb support time, and cadence was performed by group, time, and with and
without shoes as appropriate. The significance level for all comparisons was set at P