a survey of functional knee brace usage...

A SURVEY OF FUNCTIONAL KNEE BRACE USAGE FOLLOWING ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION - A PILOT STUDY

by

Anne E. Rankin

Department of Physical Therapy

Submitted in partial fulfillment of the requirements for the degree of

Master of Science

Faculty of Graduate Studies The University of Western Ontario

May 1997

O Anne E. Rankin 1997

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ABSTRACT

The purposes of this survey were to document compliance of functional knee

brace (FKB) Wear among individuals with anterior cruciate ligament (ACL)

reconstruction, and to look for patterns and issues that may influence brace

Wear. A questionnaire developed by the author was mailed to 140 patients who

had undergone an ACL reconstruction and who had been prescribed a FKB by

one of four surgeons at the Fowler Kennedy Sport Medicine C h i c (London.

Ontario). Seventy-seven questionnaires were returned for a total response rate

of 59%. Results indicate that 26% of respondents did not fiIl their prescription

for a FKB. Those who purchased a FKB wore their brace 78% of the tirne that

they participated in sports that involved quick changes of direction. There were

no significant differences found between young (1 8-35 yrs) and older (36-65 yrs)

age groups or between males and females for any of the items sampled.

Slippage of the brace was a problem 54% of the time the respondents wore their

brace. Skin irritation was considered a problem for 46% of the FKB group. The

number of sports participated in by each respondent decreased by one sport

post-surgically, and their subjective level of performance decreased by 40%.

with 60% of the respondents reporting that they changed how they participated

in their sports. Stepwise linear regression indicated that, at best, 41% of the

variance in brace Wear during sports that require quick changes of direction, was

accounted for by the following three variables in combination: patient perception

iii

of FKB effectiveness, knee buckling while wearing their FKB and brace slippage.

Further investigation is required to determine other predictors of FKB

compliance. Although 84% of the respondents felt that their brace was effective

in allowing them to be active, 26% of the original sample did not purchase a

FKB. The extent to which financial constraints prompted the decision not to

purchase a FKB needs to be determined. Future investigation should also

examine the compliance rates for other knee braces, such as neoprene knee

sleeves as a cheaper alternative to FKB's, and document the changes in

performance with these braces, as well as injury rates with bracing.

Key words: functional knee brace, compliance

DEDICATION

This is dedicated to my mother, and late father, who instilled in al1 their children a thirst for knowledge and a love of books. This is also dedicated to my husband David. and son Evan, whose encouragement, love and support, made this dream possible for me. I love you both.

I would like to thank the many people in my life that helped me to achieve a dream without the sacrifice of my sanity ... ... ... ..

To Dr. John Kramer for the support, advice and sense of humor while doing what, at times, must have seemed pretty humorless. I appreciate al1 your coaching and pushing for a better product.

To Pat Darling and Margaret Lee for their help in getting me through numerous last minute funding deadlines. Their wizardry at the computer. And for allowing me to blow off steam prior to exams.

To Dr. Linda Miller for guiding me through statistics, and allowing me to see numbers in a human Iight.

To my classrnates- especially Trevor Birmingham for the help in statistics and the availability of his computer, but mostly for sharing some good laughs. To Jenn Wuon, for helping me to see that nothing beats the rigors of scientific research a.k.a. "Shoppers Weekly" and the biweekly brownie hostage situation.

To Bev Padfield whose dedication to our profession and life long learning is an inspiration to me and to al1 who know her.

To the faculty of Elbom College who allowed me to TA. and enjoy an environment of support and learning.

To Anna Hale, Betty and Kathy, and Drs. Fowler, Amendola, Litchfield and Kirkley, for al1 their help gathering subjects, and advice in the development of this survey.

To Drs. George Wong and Duncan Mackinlay for their help in pre-testing the survey.

TABLE OF CONTENTS

CERTIFICATE OF EXAMINATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii ... ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . III

DEDICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ACKNOWLEDGEMENTS vi

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TABLE OF CONTENTS vii LIST OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix LIST OF FIGURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi LIST OF APPENDICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xii

CHAPTER ONE: INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 LITERATURE REVIEW . . . . . . . . . . . . . . . . . . . . . . . 4

1.1 FUNCTIONAL KNEE BRACES AND PATIENT OPINIONS ABOUT THElR BRACE . . . . . . . . . . . . . . . . 4

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 COMPLIANCE 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 PURPOSE 10

CHAPTER TVVO: METHOD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . II

2.1 SUBJECTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.2 SAMPLE SlZE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.3 PROCEDURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.3 MEAUSUREMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2.4 DATAANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

CHAPTERTHREE: RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

CHAPTER FOUR: DISCUSSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 4.1 LIMITATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 4.2 FUTURE RESEARCH . . . . . . . . . . . . . . . . . . . . . . . . . . 34 4.3 CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 4.4 CLlNlCAL SlGNlFlCANCE . . . . . . . . . . . . . . . . . . . . . . -36

TABLES AND FIGURES: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - 3 7

APPENDIX A: Sample size calculation and test-retest reliability of questionnaire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

APPENDIX 6:

APPENDIX C:

Letters of information and consent . . . . . . . . . . . . . 60

Ethics Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 vi i

REFERENCES . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 VlTA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

viii

Table

LIST OF TABLES

Description Page

Dernographic characteristics of respondents . . . . . . . . . . . . 38

Frequency of reconstructed knee (WL) . . . . . . . . . . . . . . . . . 39

Frequency of responses to Item 1 : Part a . . . . . . . . . . . . . . 40

Frequency of responses to Item 1 : Part b . . . . . . . . . . . . . . -40

Means and standard deviations of responses to Item 2 . . . . 41

Analysis of variance summary for Item 2 . . . . . . . . . . . . . . . 41


Analysis of variance summary for Item 3 . . . . . . . . . . . . . . . . 43


Analysis of variance summary for Item 4 . . . . . . . . . . . . . . . 45

Frequency of responses to Item 5 . . . . . . . . . . . . . . . . . . . . 47

Frequency of responses to Item 6 . . . . . . . . . . . . . . . . . . . . . 47

Frequency of responses to Items 7 and 8 . . . . . . . . . . . . . . . 48

Frequency of responses to Item 9 . . . . . . . . . . . . . . . . . . . . . 49

Means and standard deviations to Item 10 . . . . . . . . . . . . . . 50

Analysis of variance summary of Item 10 . . . . . . . . . . . . . . . 50

Frequency of responses to Item 11 . . . . . . . . . . . . . . . . . . . . 52

Means and standard deviations of responses to Item 12 . . . 53

Analysis of variance summary fo Item 12 . . . . . . . . . . . . . . . 53

ix

Table

20

Description Page

Response frequency to: What is the brand name of your brace? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Mean and standard deviation to item: How long have you hadyourbrace? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Frequency of response to item: Who paid for your brace? . 56

Frequency of response to item: Do you think you got good value for your money? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Multiple regression of independent variables to criterion: compiiance of FKB during sports that require quick changes of direction.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Figure

LIST OF FIGURES

Description Page

Mailed Questionnaire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Means and standard deviations for response to Item 2 . . . . . 42



. . . Means and standard deviations for response to Item 10 -51

. . . . Means and standard deviations for response to Item 12 54

LIST OF APPENDICES

Appendix Description Page

A Sample size calculation and test-retest reliability of questionnaire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

B Letters of information and consent . . . . . . . . . . . . . . . . . . . 60

C Ethics approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

CHAPTER ONE

INTRODUCTION

During the late 1 9601s, and early 1970's the use of knee bracing in the

treatment of anterior cruciate ligament (ACL) deficient knees became prominent

(Liu and Mirzayan 1995). Over the last three decades, many types of braces

have been designed to stabilize the ACL deficient and reconstructed knee joint.

In 1984 the American Academy of Orthopaedic Surgeons Sports Medicine

Cornmittee classified knee braces into the following categories: (1 ) prophylactic,

(2) rehabilitative, and (3) functional (Wirth and DeLee 1990). Current braces,

however, fit into al1 three categories, in that they are used to prevent injury

during the rehabilitation phase and thereafter. They are thought to permit

individuals to participate in activities that they could not otherwise do.

In Canada, as part of the ACL reconstructed patient's post operative care,

patients are often advised to purchase a functional knee brace (FKB) for use

while engaging in sporting activities. Theoretically, the extemal support

provided by the FKB will protect the knee from further injury while the patient is

participating in high risk sports (sports which require the person to plant their leg

and pivot, and are characterized by quick changes of direction, starts, stops,

and cutting movements) (Walker et al 1988, Rink et al 1989, Wojtys et al 1990,

Wirth and DeLee 1990). Custom FKB's cost approximately $1,000. which is

prohibitive for some people, unless covered partially or wholly by third party

insurance.

In a recent review of FKB prescription practices in the United States.

Decoster et al (1995) surveyed 125 members of the American Orthopedic

Society for Sports Medicine and 80 former fellows of the Kerlan Jobe Orthopedic

Clinic, to gather data on the opinions and practices of these specialists. The

response rate was 56%, with 67% of respondents prescribing FKB1s for at least

75% of their reconstruction patients and 54% bracing al1 their post-

reconstruction patients. The investigators also reported that 17% of respondents

were bracing fewer patients, 4% were bracing for shorter periods of time and

that 5% had changed from custorn to off-the-shelf FKB's (Decoster et al 1995).

Fifty-nine percent of respondents stated that 75% of their prescriptions were for

custom braces, and 61% also reported that they selected the brace themselves.

The respondents preferred custom made braces (77%), and hard shell braces

(69%), basing their bracing decision on the sport andlor level of cornpetition of

their patients. Regarding the brace prescription practices of this group, 64%

reported having made no changes, 17% were bracing fewer patients, 5%

reported changing from custom to off-the-shelf braces and 4% reported that they

are keeping their patients braced for shorter periods post- operatively. The

trend to bracing fewer patients and the usage of off-the-shelf braces versus

custom made may be reflective of a greater cost-consciousness on the part of

the physicians. However, the efficacy of both practices is unclear (Beck et al

1986. Wojtys et al 1990). Decoster et al (1 995) concluded that there were little

objective data available upon which to base a decision regarding which to

choose, an off-the-shelf or custom brace.

In a recent review of FKB's and dynarnic performance. Kramer et al

(1997) questioned the effectiveness of the FKB. They concluded that the

objective, performance based data justiwing the use of FKB's was not

compelling. In addition, a number of problems with these braces has been

identified by FKB usen, namely: skin irritation. slippage of the brace distally,

giving way or buckling of the knee while wearing the brace, weight, size, and

difkulty doffing and donning the brace (Colville et al 1986, Rink et al 1989).

Subjective responses by FKB users and static testing (passive, non-weight

bearing conditions) also suggest that the extent to which these braces control

anterior shear of the tibia on the femur may be limited to low load conditions

(Anderson et al 1992, Bassett and Flemming 1983, Branch et al 1988, Cawley et

al 1989, Krarner et al 1997. Knutzen et al 1987. Liggins and Bowker 1991, Liu et

al 1994, Mishra et al 1989, Wojtys et al 1990). However, there is some

evidence that the ACL deficient and reconstructed patient subjectively feels

more stable, has better performance when braced and experiences fewer

instances of giving way (Kramer et al 1997. Marans et al 1991, Rink et al 1989.

Tegner and Lorentzon 1992). What weighting the subjective opinions of the

patient should be given, relative to the objective performance tests is unclear.

To what extent subjects actually Wear their braces and at what level of

performance they function after surgery are also unclear.

Cornpliance as defined by Mosby's Dictionary, (4th edition) is "the

fulfillment of the care-giver's prescribed course of treatment". Patients however,

may not understand cornpliance in terms of the "medical model", but rather

within the context of their own lifestyle. Factors such as the costs and benefits

of following the doctor's prescription to purchase a FKB, level of sporting

activity, risks that they perceive with continued activity, their post-surgical status

of comfort and strength, their experiences with the brace, and their financial

status may al1 effect the patient's decision to use, or even purchase a FKB

(Donovan and Blake 1992, Kramer et al 1997). Whether the patient

understands exactly when and under what circumstances they are to wear, or

discontinue usage of their FKB, and what proportion of patients actually

purchase and use a FKB are unclear. Whether or not the patient's compliance

with FKB Wear impacts on the long term activity pattern is also unclear.

LITERATU RE REVIEW

Functional Knee Braces and Patient Opinions About Their Brace

Colville et al (1986). as part of a study to determine the effectiveness of

the Lenox Hill brace, questioned 45 patients with ACL deficient knees. The

subjects were asked about their level of athletic ability, and activity before and

after injury, compliance with brace wear, degree and symptoms of instability in

and out of the brace, satisfaction with the brace, and effect of the brace on

athletic performance. They concluded that brace Wear while jogging was

universally unacceptable. While 27 subjects (60%) reported wearing their

braces only for strenuous, twisting sports, 18 (40%) wore their brace for al1

sporting activities except jogging. Functional knee brace Wear compliance was

estimated to be about 57% when the patients felt that they were at risk of re-

their brace at least 75% of the time that

Patients complained of chafing, brace

injury, while 24% claimed that they wore

they were exposed to high risk sports.

slippage and pain, but maintained that they continued to Wear their FKB despite

such problems. Sixty-two percent of these patients continued to experience

symptoms of knee instability while wearing their FKB (versus 89% without the

brace), and yet 91 % reported that they were satisfied with their brace.

Rink et al (1989) also questioned ACL deficient subjects who were

included in their study evaluating the effectiveness of several FKB's. which also

included functional testing (n=14). Each subject was requested to Wear one of

three braces for one month at a time, in a random order and then asked to

evaluate a number of subjective items. The questionnaire evaluated pain,

swelling, weight of the brace, slippage, running speed when braced, and

whether the subject would Wear the brace. The questionnaire used a scale of

eleven points, where zero represented no pain, swelling, etc. Of the 14

subjects, four (29%) experienced five subluxation events during the course of

their study and yet they reported an "excellent subjective response to wearing

braces". All subjects (n=14) reported a decrease in the subjective symptoms of

knee instability, swelling, and pain for each of the three braces that were tested.

Different preferences for the different braces tested were reported by each of

the subjects. The braces were evaluated on the basis of ease of application,

cornfort, weight, level of performance allowed and slippage. The authors

considered it necessary that patients with anterolateral rotary instability who are

using FKB's, also undergo activity modification. There is some question of the

intemal validity of this questionnaire because the grading system that was used

was not scaled consistently from question to question. For example, no pain

was rated at zero points, and no limitation to overall activity level was given ten

points. As a result, the rnost desirable outcome had a score of zero in one case

and a score of ten in another. There was no report of evaluation of cornpliance

within the different bracing periods.

Tegner and Lorentzon (1 991 ) examined the use of prophylactic FKB's by

elite Swedish hockey players. They surveyed 600 players, reporting that 42% of

the group that had previousiy injured their knee and approximately 12% of this

group had a tear of the ACL. Of the 27 players with ACL tears, 18 (66%) had

reconstructive surgery and four (14.8%) continued to play without their FKB. In

order to prevent the over or underestimation of the severity of knee injury, only

injuries diagnosed by a physician were registered. They experienced a non-

response by a number of teams surveyed (response rate was 74.5%).

Kramer et al (1997) reviewed the results of dynamic performance tests

and the effectiveness of FKB's. As evidenced from their review, there was no

advantage to FKB when objective testing was used as the basis for decisions to

brace. However, five of the 12 performance studies reviewed indicated that their

subjects felt subjectively more stable, had fewer instances of giving way, and felt

their performances were enhanced when braced. Despite this, only three of the

studies cited supported these comments with objective evidence of improved

performance during maximal effort tests or altered performance during rnatched

effort tests. As a result, the subjective opinions of the patient may not be

directly linked with performance outcome.

Methods of rneasuring subjective complaints have become more

important in the evaluation of outcome measures with the advent of patient

based care (Mohtadi 1993. Donovan and Blake 1992). The use of an eleven

point scale, such as that used by Rink et al (1989), has several limitations. Most

importantly, the options that are given to the patient to check are limited to those

defined by the researcher. It is possible to phrase questions and responses so

that biases are encouraged by the researcher (Mohtadi 1993, Raj 1972,

Scheaffer et al 1986). In order to elirninate bias, the response options can

become so lengthy that the questionnaire becomes onerous to complete

(Woodward and Chambers 1980). The use of visual analogue scales (VAS)

was successfully ernployed by Mohtadi (1993) in a survey designed to evaluate

the quality of life of patients who had not undergone ACL reconstructive surgery.

The quality of life assessrnent examines the subjective measures of outcome

with regards to the ACL deficient knee in five separate domains using VAS.

These included symptoms and physical complaints, sporürecreational concerns,

work-related concerns, life-style, and sociallemotional concerns.

Flandry et al (1 991) found that the results using a VAS. when measuring

subjective knee complaints, were valid and comparable to other methods that

used scoring scales. In a prospective study, 117 patients who had undergone

knee surgery, and 65 patients at their initial office evaluation for a knee problem

were asked to complete a form that utilized a VAS scale to measure their knee

complaints. The results of the VAS form were compared to three other types of

established knee outcome forms which were completed by the subjects in a

random order. The respondents found the VAS easier to complete (Flandry et al

1991 ) and that by providing for a larger variety of responses, they removed the

examiner's bias (Flandry et al 1991, Mohtadi 1993). The use of a VAS provides

greater sensitivity by allowing a greater range of responses. and greater

statistical power in the interpretation of the respondents' responses.

Compliance

Compliance has been studied extensively in chronic medical conditions

such as rheumatoid arthritis and heart disease. Donovan and Blake (1992)

reported that 8000 English language articles on compliance have been listed on

Medline alone up to 1990. Their study examined the reasoning used by patients

who demonstrated "non-cornpliance". The three main types of non-cornpliance

were: 1) discontinuation of medication, 2) alteration of the dosage or altering

the timing of the dosage and 3) taking a higher dosage than prescribed. The

main reasons listed for non-cornpliance were those of side-effects; the patient

was unsure of why they were to take the medication, or Wear their splints, or that

the patient did not see any benefit to the treatment. The authors maintained that

patients do not consider compliance to be an issue, and that non-cornpliance is

not deviant behavior, but rather reasoned decision making, made after the

patient conducts their own cost-benefit analysis for the treatment offered.

Feinberg (1 988, 1992) examined the effect of patient-practitioner

interaction on compliance in a patient population of rheumatoid arthritis. In the

treatment of chronic illness, treatment effectiveness is determined in part, by the

efficacy of the treatment and therefore patient compliance. Feinberg (1 992)

maintained that the most important factor in compliance was the physician-

patient relationship, and therefore within this study she examined the effect of

patient-practitioner interaction. Forty subjects were randomly assigned to a

standard treatment group or to a cornpliance-enhancement group. The

experimental group was offered a more positive and supportive interaction with

the occupational therapist during the initial wrist splint fitting session. The

emphasis was on patient education, while the control group received

conversation Iimited to sufficient instruction to ensure the correct use of the

splints. Feinberg (1992) found that the experimental group were more likely to

use the resting splints than the control group.

The nature of the instructions given to patients may be clear to

physicians, but the patient's understanding of these directions rnay be quite

different. Presently, the ACL reconstructed patient's understanding about their

brace, when it should be used, and why they should Wear it has not been

documented. What the FKB users compliance rate is during "at risk" activities,

sports that require quick changes of direction, cutting movements and starüstop

activities, has not been determined. There has been no investigation of patients'

long term experiences with their FKB, and their subjective impressions of its

value. Prolonged use of the FKB may produce sweating, discornfort, and

slippage, al1 of which may impact on the patient's desirelcompliance to Wear

their FKB. The effectiveness of FKB's in these circumstances has not been

adequately addressed in objective or subjective terrns. To date, the compliance

rates in AC1 reconstructed patients or possible predictors of brace Wear

cornpliance are undocumented.

PURPOSE

The purposes of this pilot study were to 1) determine compliance scores

for FKB Wear in a group of ACL reconstructed patients, during periods of

sporting activity and during at risk activities (sports requiring quick changes of

direction, frequent stoplstarts and cutting movements); 2) to determine the

sports in which the subjects used their FKB; 3) to determine what the patient's

understanding was of when the FKB was to be used; and to 4) determine issues

that may help predict compliance with FKB use.

CHAPTER TWO

METHOD

SUBJECTS

A list of al1 patients having undergone ACL reconstruction during a six

month period at the London Health Sciences Center, University Campus

(London, Ontario) (n=262) was compiled by the staff of the Fowler Kennedy

Sports Medicine Clinic (University of Western Ontario, London, Ontario). From

this list it was determined that 140 patients met the following inclusionlexclusion

criteria: 12-1 8 months post-reconstruction of their ACL, prescribed a FKB by

their surgeon, greater than 18 years of age, and asymptomatic or with minor

pathology of their contralateral lower extremity. Subjects were excluded if they

reported serious pathology of their contralateral knee, hip. ankle or back

conditions which would preclude normal activity; neurological conditions such as

Parkinson's, stroke, multiple sclerosis or peripheral neuropathies. A variety of

surgical reconstruction methods performed by a total of four surgeons were

included, including: patellar bone-tendon-bone graft, semitendinosus and

ligament augmentation device, and also the use of the semitendinosus/gracilis

tendon graft. Descriptive information on age, sex, type of injury, type of

reconstructionl surgery date, health of opposite knee and type of brace

prescribed was recorded from the medical file of individuals meeting the

inclusionlexclusion criteria.

ACL reconstructed patients at the Fowler Kennedy Sports Medicine Clinic

are prescribed a FKB at six months post surgery. Surgeons discuss the level

and type of activity in which the patient can be engaged. Financing of the brace

is also discussed in order to best detemine what type of brace will be

prescribed, custom or off-the-shelf. Patients are instructed to Wear their brace

during activities (sports or work) that include pivoting, quick changes of

direction, andlor acceleration/deceleration actions. They are also instructed that

they may discontinue brace use at 18 months if they wish. The primary rationale

for FKB use between 6-1 8 months at the Fowler Kennedy Sports Medicine Clinic

is that proprioceptive retraining of the knee should be completed at 18 months.

SAMPLE SlZE

As no standard deviations from previous studies were available on which

to base a sample size, estimates were calculated using a sample error

calculation based on proportions (a, = w n ) ; wwhere p is the proportion of

population that is compliant with FKB Wear, q is the proportion that is non-

compliant and n is the sample size (Babbie 1973, Raj 1972). With a response

of 100 suweys returned and a possible cornpliance rate of 50%. the 95%

confidence interval for sampling error would be t 9.8% (see Appendix A). This

would mean that 95% of the population will be compliant 4060% of the time.

PROCEDURES

Potential subjects (n = 140) were contacted by mail in September, 1996

and asked to complete a self-administered questionnaire (Figure 1) regarding

their FKB Wear habits, problems they may be experiencing while wearing their

brace, and their opinions regarding their level of activity. Four weeks later a

rerninder letter (Appendix B) was sent if the questionnaire had not been

returned. Collection of data was completed in January 1997.

Figure 1 : Mailed questionnaire.

1. When you received your brace you were given instructions as to when you should Wear your brace. Please explain what your understanding is of when you should be wearing your brace.

What is your primary sport?

How often do you Wear your brace when participating in sports that involve quick changes of direction. or require you to plant your leg and twist?

never always

How often do you Wear your brace when parücipating in your primary sport?

never always

Has your level of performance in your primary sport changed from before you injured your knee?

a lot worse same

Please explain:

5. Have you had to change the way you play your primary sport? Y ~ S O NO^ If your answer is yes, is it by limiting your pafücipation, changing the way you perfom certain skills, or avoiding particular activities? 1. Limit 2.Change 3. Avoid Please circle one answer.

Please explain:

6. Overall, do you think your brace has been effective in allowing you to be active? ~ e s n NO^

Please exdain:

7. Please check the boxes beside the sports that you participated in before your knee injury. footballn basketballn volleyballn soccern lacrosseO downhiil sk i ingo cross- country ski ingo hockeyn figurelspeed skatingn rollerblading[7 aerobicso racquet sportsn o thern Please list if other:

8. Please check the boxes beside the spows you participate in now. footballO basketbail vo l leyba l l~ soccern lacrossen downhill sk i ingo cross-country sk i ingo hockey figurelspeed skatingn rollerbladingn aerobicsu racquet sportsn o thern Please

list if other:

9. Have you experienced any giving way or buckling of your knee dunng any activity, while wearing vour brace? ~ e s O NO^ If yes, please explain how often:

10. Do you experience problems with your brace slipping?

always never

1 1. Do you experience discornfort or skin irritation as a result of wearing your brace? ~ e s u

12. Do you continue to cany out knee strengthening exercises, in addition to your other recreational activities?

not at al1 every day

Below are several questions regarding your current brace.

What is the brand name of your brace? Is this brace custom m a d e n or off the shelfO?

About how long have you had your curent brace? Years Months

Who paid for your brace? Please check the most correct answer. oursel la W C B ~ Third paity insurance0 If a combination please check the appropriate boxes. Do you think you got good value for your money when you purchased your knee brace? ~esn NOCI

Thank you for participating in this survey! Please enclose this questionnaire in the stamped, addressed envelope provided, and mail as soon as possible. Would you like the results of this survey? Please check: ~ e s n NO^

MEASUREMENT

The questionnaire was designed by the author and was reviewed by four

orthopedic surgeons at the Fowler Kennedy Sports Medicine Clinic, as well as

six physiotherapists, and an epidemiologist. Modifications were made prior to

testing on six subjects, exclusive of the study, who met with the author. These

individuals completed the questionnaire and discussed its ease of use, their

understanding of the items and length of time for completion. They also

completed the same questionnaire one week later and returned this by mail, in

order to provide some information on the test-retest reliability of the

questionnaire.

The final questionnaire included check boxes, short answer questions

and visual analog scales (VAS). ltem 1 examined the instructions given the

respondents by their surgeon when they received their brace prescription. This

question reflected the patient's understanding of when their FKB should be

worn. ltems 2 and 3 addressed the cornpliance rate for FKB usage in h o

situations: 1 ) participation in traditionally defined "at risk" sports, those involving

quick changes of direction and starüstop activities, and 2) participation in the

respondent's primary sport (as it was not known if this would be considered an

"at risk" sport or not). ltems 4, 5 and 6 examined the respondent's attitudes

towards their brace and extent to which they believed that the brace allowed

them to perform their activities. ltems 7 and 8 examined sport participation

before and after surgical intervention. Items 9, 10 and 11 exarnined problems

previously associated with FKB W e a r (Colville et al 1986, Rink et al 1989). ltem

12 examined compliance with the long term strengthening programs, typically

recommended as home exercises. The remaining items examined brace type.

how long the subjects have owned their current brace, method of payment for

the brace and perceived value of the FKB to the respondent.

The VAS used throughout the questionnaire was based on a 10 cm long

line. across which the respondent made a mark to indicate their response. The

length of line from its start to the point of the subject's mark was used as the

criterion score, measured in centimeters. The scale was chosen such that zero

represented maximum non-compliance and a ten represented maximum

compliance. Other VAS scales were structured so that zero represented worst

performance or most problems and ten optimal performance or no problems with

their brace.

Data Analysis

Descriptive data from the subjects' files and their questionnaires were

entered into a spreadsheet by the author (Excel 7 Microsoft Corporation 1994).

Data were originally grouped on the basis of whether or not the patient's brace

prescription was filled, age, and gender. These groups were further subdivided

by age into groups of 18 to 35 years of age (younger) and 36 to 65 years (older).

Analysis of the data was completed using SPSS 7.0 (SPSS Inc. 1996).

lndependent t-tests (nondirectional) and analysis of variance tests were used to

compare VAS scores.

Multiple linear (stepwise) regression was used to determine the extent to

which the criterion measure of brace Wear compliance (Item 2) could be

predicted from six variables (Pednazur 1982): effectiveness of the brace as

perceived by the client (Item 6), buckling of the knee while wearing the brace

(Item 9), slippage (Item IO), skin irritation (Item 1 l ) , compliance to a long term

strengthening program (Item 12) and patient perception of the value of the brace

in consideration of the cost (brace information) (Colville et ai 1986). The 0.05

level was used to denote statistical significance throughout testing.

CHAPTER THREE

RESULTS

An analysis of the test-retest data (n=6) indicated that the questionnaire

was reliable (Appendix A). The range of Pearson Product Moment Correlations

were from r = 0.89 (Item 12) to r = 1.00 (Items 1, 6, 9, and 11) (p c 0.05).

Responses to Items 2 and 3 were closely related (r = 0.87, p c .01), indicating

that these two items shared about 76% of their variance (? = 0.76).

Of the 140 surveys mailed, nine were returned by the post-office as

undeliverable. Seventy-seven of the patients surveyed (n=131) completed and

returned the questionnaire (a response rate of 58.78%). Descriptive data are

presented in Tables 1 and 2. The No Brace group represented 25.97% of the

total of respondents with the remaining 74.03% purchasing a FKB. The mean

time from surgery for the Braced group was 21 months (3.84). There was no

statistical difference between the time from surgery for the Brace and No Brace

groups. The mean time between injury and surgery was 1 1.73 months (1 0.91 ).

Four respondents were characterized by a mean time of greater than 93 months

and were excluded from this calculation only.

No significant differences were observed between males and females for

the brace and no brace groups on age. Of the braced group (n = 57), Item 1

indicated that 54.4% (31) understood that they should Wear their brace for

pivoting starVstop sport participation (Table 3). Table 4 details the breakdown

of the primary sport as indicated by the respondents.

The compliance

requiring quick changes

score for the total group (n=57) for Item 2 (sports

of direction) was 7.75 (3.33) (with four subjects scoring

zero. and 22 subjects scoring ten) and for item 3 (when participating in their

primary sport), 7.53 (3.77) (with five subjects scoring zero and 28 subjects

scoring ten). The young and old age groups, and males and females.

demonstrated similar levels of compliance for brace use during sports requiring

quick changes of direction, and for their primary sport (p > 0.05) (Tables 5, 6. 7.

8, and Figures 2 and 3).

The mean change for level of performance of the patient's primary sport

for the group was 6.09 (3.17) (with only one subject scoring zero and eight

. subjects scoring ten). The young and old age groups, and males and females

al1 experienced a similar level of performance of their primary sport (p > 0.05)

(Tables 9 and 10, and Figure 4). Correlation between time from injury to surgery

and level of performance of r = -0.33 (p < .05), suggesting a poor relationship.

Nineteen respondents (33.3%) reported that they did not change the way

they performed their primary sport, while 38 respondents (66.7%) said they did

modify their performance (Table 11). Forty-eight respondents (84.2%) felt that

their brace was effective in allowing them to be active, while 7 (12.3%) felt it was

ineffective (Table 12).

The responses to items 7 and 8 were very diverse with al1 respondents

participating in more than one sport prior to injury, and after surgery (see Table

13 for a breakdown of different sport participation). In general, subjects

participated in fewer sports post-surgery.

In response to ltem 9, 24.6% of the respondents reported that they had

experienced buckling while wearing the FKB (Table 14). All stated that it was a

rare occurrence with only one respondent re-injuring their knee while wearing

their brace. ltem 10 examined brace slippage. The slippage score of 4.63

(3.37) (with four subjects scoring zero and five subjects scoring ten) for the total

group (Tables 15 and 16, and Figure 5) indicated that slippage was a problern

53.7% of the time that the brace was worn. The responses to ltem 11, indicated

that 26 (45.6%) of respondents did experience problems with skin irritation or

discornfort while wearing their FKB, while 31 (54.4%) were problem-free (Table

17).

Item 12 examined compliance with long terrn knee strengthening regimes,

and indicated the group score to be 4.93 (3.04) (with six subjects scoring zero

and two subjects scoring ten). Again, young and old, and males and females

had similar levels of compliance with their exercise regirne (p > 0.05) (Tables 18

and 19 and Figure 6)

The remaining questions focused on the FKB itself. The first question in

this section concerned the brand of brace and whether or not it was custorn

made or off-the-shelf (see Table 20). 89.5% (n = 51) of the brace prescriptions

filled (n = 57) were for custom fit braces. The mean length of brace use was

23.04 months (18.93) for females and 22.61 months (18.03) for males (Table

21). Payment was made by insurance companies for 37 (64.9%) of the

respondents (Table 22). Finally, 43 subjects (75.4%) felt that they had received

good value, considering the cost of the brace, while 11 (19.3%) stated the

opposite (3 respondents did not answer this question) (Table 23).

A multiple regression analysis was completad with compliance during

sports that require quick changes of direction as the dependent variable (Item

2). The continuous and dichotomous variables that were thought to be possible

predictors (slippage of the FKB, skin irritation or discomfort, buckling of the knee

while wearing the brace, patient perception of effectiveness, compliance with an

exercise regime, and level of performance) were entered into the regression.

Using a stepwise regression method, 40.7% of variability in FKB compliance

was explained by patient perception of effectiveness, knee buckling while

wearing their FKB, and brace slippage (R = 0.64, F(3.45) = 10.31, p c 0.01) with

effectiveness explaining 27% ( R * ~ = 0.27), knee buckling explaining 7% ( R ~ ~ =

0.07) and slippage 6% ( R ~ ~ = 0.06) (see Table 24). The remaining three

variables (exercise compliance, level of performance and skin irritation or

discomfort) made no significant contribution to the overall prediction and

therefore were discarded from the equation.

CHAPTER FOUR

DISCUSSION

The present sample included a large age spread (18-61 years), with

64.9% in an age group (1 8-35 years) which is typically associated with great

mobility. The response rate in the present study of 58.78% approached the

high limit for the ranges reported by Portney and Watkins (1993) and Babbie

(1 973) for mailed survey response rates (60%). Mohtadi (1 993) reported a 75%

response to his survey examining quality of life as an outcome measure in ACL

reconstnictive surgery, but this questionnaire was completed at the physicians'

office. Tegner and Lorentzen (1991) also had a response rate of 75% for their

mailed questionnaire, although it is unclear who mailed the survey in, the

physician or the hockey player. Other studies evaluating subjective knee

symptoms did not utilize a mail-in questionnaire and therefore had a rnuch

higher rate of return.

The 26% of the respondents that did not fil1 their brace prescription was

unanticipated by the author. as the surgeons at the Fowler Kennedy Sports

Medicine Clinic felt they did a thorough pre-screening of individuals prior to

recommending the purchase of an FKB. Factors such as level of participation in

sports that would put the reconstruction at risk, level of competition, and method

of payment are al1 considered prior to prescribing a brace. It is unclear if the

respondents did not fiIl their prescription because of rnonetary concems, or if

they had not returned to the activities that woulci put their ACL reconstruction at

risk, and therefore did not feel the need of a FKB.

A major requirement for patients to comply with instructions is that they

be able to understand the instructions that are to be carried out. In the present

study it is apparent that 54.4% of the respondents understood that they were to

Wear their FKB when they were participating in sports requiring quick changes of

direction. The remaining 40.4% who received instructions may have been

instructed to Wear their FKB while participating in al1 sports or at work,

depending on the degree of instability present in their post-surgical knee, and

the type of work they engaged in. This is similar to the findings of Colville et al

(1986) who reported that 60% of the patients they tested used their brace for

strenuous, twisting sports only, while the remaining 40% used it for al1 sports

except jogging. In the present study, 5.3% who did flot receive instructions were

either physical therapists or physical therapy students, and their surgeon may

have felt that it was redundant to explain when they were to Wear their FKB.

The total group of respondents had a compliance rate of 77.5% (t33.3%).

This is substantially higher than the rate reported by Colville et al (1986), who

reported that the compliance rate in AC1 deficient knees was 57% when

participating in "at risk" sports. It is unclear if the different compliance rates are

secondary to the improvements made in FKB's over the past decade, or if the

desire to protect their reconstructed knee in the present study was higher than

the group that did not undergo surgery in Colville et al's study (1986). The

strong agreement between the scores of Items 2 and 3 (r = 0.87, p< 0.01), -

compliance with FKB Wear during sports that put the ACL reconstruction at risk

versus the respondent's primary sport may be secondary to the prevalence of "at

risk" primary sporting activity for this specific sample. Typically, surveys do not

utilize questions with such high correlations between items because it is felt that

one item provides nearly as much information as the two items. Although Item 3

may be redundant to the questionnaire for the present study, further testing with

other populations will be required before its elimination from the survey.

Items 4 and 5 examined if the respondents changed the way they

participated in their primary sport and the subjective opinion of the respondent

about their post-surgical level of performance. The mean subjective level of

performance decreased by 40% for the respondents with a FKB. The primary

reason given for the decrease in level of performance was that respondents

feared re-injury, and therefore voluntarily limited their performance. It was

decided that the subjective level of performance would be used as this may be

an indicator of their satisfaction with their knee reconstruction, and also their

FKB. As well, quantifying overall performance was well beyond the scope of the

present study. The responses used in this questionnaire for this item were

"same" for a score of ten and "a lot worse" for a score of zero. Only one subject

scored a zero on this item, while 14.5% (n=8) stated that they were able to

perform at the same level. The low correlation between level of performance

and time from injury to surgery (r = -0.33) would indicate that this was not an

important contributing factor to determine the level of performance achieved.

Colville et al (1986) reported that 22% of ACL deficient patients were able to

achieve the same level of athletic performance without a brace and that 47%

were able to achieve this with the aid of their FKB. It is difficult to objectively

measure post-surgical performance and compare to pre-injury performance,

unless coaches have developed and use functional tests that mimic the activity

(cutting and agility drills, sprinting, figure-of-eight runs etc.), prior to the subject's

injury.

It may be possible to perform at the same level, but the subjects had to

modify the skill set required by their particuiar sport. Only 33.3% of respondents

in this study indicated that they had not changed the way they performed their

primary sport, with the remainder (66.7%) modifying their performance by

changing their method of play (38.6%), limiting their participation (1 5.8%), or

avoiding particular activities (1 2.3%).

Rink et al (1 989) advocated that activity modification as well as FKB Wear

were necessary for the reconstructed knee, however it is not known if on the

field technique modifications increase or decrease the risk of re-injury. Noyes et

al (1989) reported that one of the difficulties in using knee rating systems to

measure activity level is that they often do not detect the "knee abuser", the

patient who returns to sports but continues to experience symptoms that are

harmful to their knee in the long term. Patients rnay modify athletic activity for

many reasons including change of interest, time available for participation,

graduation from school, or limitations from the injury (Noyes et al 1989).

Perhaps the decrease in performance level is an indicator of the subject's

desire to protect their knee from re-injury, or it may be an indication that there

continues to be a subjective feeling of instability in the reconstructed knee when

performing certain activities. Mishra et al (1989) reported that their ACL

deficient patients (n=42) did not switch to a less strenuous sport post-injury, but

rather decreased the amount of time they played at their pre-injury intensity.

Level of performance in team sports is diffÏcult to quantify because of the

difFiculty in objectively measuring the subject's contribution to the team1s own

performance level. It is unclear what the role skill level of the player or their

knowledge of teamwork and strategy have in the sporting activity performance

achieved post-surgically.

Items 7 and 8 suggested that most of the ACL reconstructed patients

decreased their activity level by approximately one sport. The sports that lost the

greatest amount of participation were volleyball (n= l I ) and downhill

skiinglsnowboarding (n=l3). A further breakdown of the data suggested that the

only high risk sports to be taken up post-surgically were racquet sports, hockey,

baseball, and lacrosse. The sports that didnJt involve quick changes of direction

and frequent startlstops, that were taken up after reconstructive surgery were

rollerblading. weightlifting, swimrning, cycling, aerobics. and cross-country

skiing. Rollerblading, cycling and weightlifting were al1 recomrnended as part of

the post-surgical rehabilitation protocol at the Fowler-Kennedy Sports Medicine

C h i c which emphasized closed-kinetic-chain exercise, and they represented

sports with the largest gain in participation.

The majority of the respondents (84.2%) felt that their FKB was effective

in allowing them to be active and that they had received good value considering

the cost (75%). Although value did not represent a significant predictor for

brace compliance in this study, patient perception of effectiveness represented

almost 30% of the explained variance for compliance during sporting activity

requiring quick changes of direction. This agrees with the findings of Donovan

and Blake (1992) who reported that patients complied with medical advice when

it made sense to them and "seemed effectiven. it appears that the respondent

believes to some degree that the FKB is improving their stability, performance or

other subjective feelings that were not measured in this study. and that this

impacts on their decision to Wear their FKB when participating in sports that

could put their AC1 reconstruction "at risk". Although 75% of the respondents

felt that they received good value for their money whec they purchased a FKB,

65% of the FKB's purchased were covered by insurance. Therefore the value

that they place on the FKB's effectiveness may be inflated. It is unknown how

important the satisfaction of the consumer is to the long-term continued usage of

FKB's.

Although the present study did not have adequate statistical power to

detect significant differences between age groups, there appeared to be a trend

for the older age group to be more compliant with brace Wear in sports that

involve quick changes of direction (mean scores 8.51 versus 7-36), in their

primary sport (mean scores 7.76 versus 7.41). and with their long term knee

strengthening exercises (mean scores 5.07 versus 4.71). The older age group

also appeared to experience less slippage (mean scores 5.57 versus 4.15) and

to be able to perform their primary sport at a level that more closely matched

their pre-injury level (mean scores 6.29 versus 5.99). The slightly higher level of

performance for the older age group may also be an indicator that their pre-

injury sport was at a lower cornpetitive level than the younger age group. The

primary factor thought to contribute to the inability to declare these differences

statistically significant, was the srnaIl sample size which resulted in high

standard deviation scores.

Knee buckling while wearing their FKB was reported by 25% of the

respondents, although it was stated that this was a rare occurrence. This value

is much lower than the 62% reported by Colville et al (1986) or the 70% reported

by Basset and Flemming (1983) in their ACL deficient patients. It is unclear

whether the contrasting findings were secondary to improvements made in

brace design in the intervening years, or to the instability associated with the

ACL deficient knee. Tegner and Lorentzon (1991) reported that 171230 (7.4%)

hockey players injured their knee while wearing FKB's, but did not record the

incidence of buckling of the knee without injury. In a study evaluating four

FKB's, Mishra et al (1 989) reported that 14% of the AC1 deficient patients used

in their study complained of giving way of their affected knee. They also

reported that giving way of the knee was the most consistently reported factor in

the subjects deciding whether or not the FKB was effective.

Skin irritation and discomfort were fairly high for al1 groups, with 45.6% of

the respondents reporting that they did have problems in this area. While Rink

et al (1 989) did not inquire specifically about skin irritation, they did report mean

brace comfort as being between eight and nine on their eleven point scale.

Their scoring system indicated that their subjects experienced only mild

discomfort with vigorous activity, to no discomfort at all. The level of skin

irritation reported in the present study rnay be related to the high level of

slippage reported (53.7% of the time that the brace is wom) by these subjects.

Brace slippage may be related to the fluctuations of limb volume associated with

changes in muscle mass associated with contraction and relaxation. FKB

prescription at the Fowler Kennedy Sports Medicine Clinic is provided at

approximately six months post-reconstruction. These patients typically would

have just completed an aggressive rehabilitation program, and may have higher

quadricepslhamstrings bulk at the time of their initial FKB fitting than perhaps at

12 months post-reconstruction (Jennings et al 1995). Rink et al (1 989) reported

the mean slippage score as approximately eight on their scale, indicating that

slippage occurred only occasionally during vigorous activities. In contrast to this

finding Mishra et al (1989) reported that FKB migration was the predominant

complaint when testing four FKBfs with ACL deficient patients. Both skin

irritation and slippage may also be secondary ta the lining of the braces. All

brace companies advise that no sleeve liner be used between the brace and

knee. However, with prolonged activity, sweating could cause problems with

FKB slippage and skin breakdown. Whether a FKB worn over a neoprene

sleeve would be advantageous is unclear, as is whether or not the sleeve would

slip in this situation.

It is interesting to note that the problems of slippage, and skin irritation

that were identified as early as 1986 (Colville et al 1986, Rink et al 1989)

continue to be problems in today's marketplace, despite efforts by brace

companies to elirninate such difficulties. The present study did not examine the

issues of weight of the FKB, or difficulty applying and removing the brace.

Cornpliance with a long term knee strengthening exercise program is

encouraged at the Fowler Kennedy Sports Medicine Clinic, through the use of

special gym passes to the clinic's facilities after discharge from active

rehabilitation and arrangements at other fitness facilities within the imrnediate

area. The compliance score of 4.93 indicated that respondents have carried out

knee strengthening exercises approximately every second day for approxirnately

one and one half years. This compliance with a long term knee strengthening

exercise prograrn rnay not be generalized to non-urban populations, where the

fitness equipment is not as readily available. At present it is unclear what the

importance of compliance with a long terrn knee strengthening exercise program

is to the patient's performance level, and if regular exercise, or what kind of

exercise, is enough to maintain the knee strength in an ACL reconstructed

patient.

As indicated in the survey of orthopedic surgeons (Decoster et al 1995))

there continues to be a high percentage of custom FKB prescriptions (89.5%)

versus off-the-shelf (10.5%), despite a Jack of objective evidence of their

superior effectiveness. The funding of FKB purchase by the insurance

companies (64.9%) rnay make it more attractive for the consumer and the

physician to opt for a custom brace. The present cost of an off-the-shelf brace

is approximately $500 as opposed to about $1,000 for a custom fit brace. This

lower cost of the off-the-shelf FKB may still be prohibitive to patients without

insurance. In the present study it is not known what percentage of respondents

did not fiIl their prescription for a FKB because they were unable to fund a brace

purchase.

Although the multiple regression indicated that patient perception of

effectiveness, knee buckling and slippage were the primary variables affecting

brace use, only 40% of the variance in compliance to brace Wear (Item 2) was

explained by these variables in combination. It appears that there are other

important factors that contribute to the patient's decision to comply with brace

Wear. While the multiple regression was statistically significant (F (3.45) =

10.31, p c 0.01) the clinical applicability of the prediction equation was doubtful

as the 95% confidence interval was i 5.04 on a scale of ten. This result

suggested that the range of scores within the 95% confidence interval was as

great as the 10 point scale itself. Another limitation associated with multiple

regression was that prediction using the formula based on this sample was only

applicable to other samples that have the similar characteristics to the present

sample.

LIMITATIONS

Surveys have certain inherent problems in their administration. The age

group receiving FKB's tends to be very mobile, busy with both schooling,

employment and sporting activities. This high activity profile and mobility, may

help account for the response rate of 59%. A prospective study having patients

fil1 in the survey at their one year check-up may address this problern. However,

patients with good surgical outcornes and activity level satisfaction, may be less

likely to attend the one year check-up, introducing an inherent bias in

respondents.

Response to surveys typically are within the 30-60% range (Portney and

Watkins 1993, Babbie 1973). The issue of systematic non-response makes

generalization to populations at large difficult. The non-responders may be

systematically different from those who respond i.e. those dissatisfied with the

FKB and their surgery (Babbie 1973, Raj 1972) . One follow-up mailing was

used to encourage greater participation in the present survey, however, three or

four follow-up mailings may have been more effective.

Sample size became an issue, not only with non-response, but secondary

to the sensitivity of the study to detect statistically significant differences. The

present study provided the standard deviations that can be used to better

determine sample size in future research, provided that questions and scales

used are comparable to those used in the present study. Unfortunately, for the

purposes of this study, measures of variation were not known to calculate a

sample size a priori.

Currently, clinically significant differences in factors such as slippage,

decrease in level of performance, or cornpliance to brace Wear have not been

quantified or related to actual performances. To date there has been no clinical

trial to determine re-injury rates, with or without a brace. The issue of slippage

has not been extensively addressed, although slippage affects the

biornechanics of the joint during activity (Walker et al 1988). It is not known if

alteration of knee movement subsequent to FKB slippage predisposes to re-

injury or promotes the development of osteoarthritis.

In the present study subjects were not questioned as to what level of

performance was important to them. The difficulties in measuring objective

performance post-surgically in cornparison to pre-injury levels, and the detection

of the "knee abuser (Noyes et al 1989) have not been addressed in the present

study .

The importance of compliance with a long terrn strengthening programs to

the level of activity of the reconstructed ACL patient is unclear. The emphasis

on post-rehabilitation exercise at the Fowler Kennedy Sports Medicine Clinic is

on continued participation in knee strengthening exercise programs. Although

rehabilitation programs have become much more intensive in the past 10 years,

it is not known if continued activity is enough to maintain the strength of the

reconstructed knee, or if supplernental exercises are required, or, to what extent

strength affects performance.

FUTURE RESEARCH

The present study did not examine the compliance rate for use of knee

devices other than FKB's. As objective support for the use of FKB's is not

compelling (Kramer et al 1997), an investigation into the use of splints such as

neoprene knee sleeves versus FKB's (both custom and off-the-shelf) should be

completed. This would help to determine if the subjective reports of increased

stability associated with FKB's is secondary to other variables such as

proprioceptive input, rather than restriction of movement provided by the FKB,

and may provide for inexpensive alternatives. The alteration of knee

biomechanics secondary to the issue of brace slippage needs to be addressed,

as this may well cause further damage to the articular cartilage, or the

reconstructed ligament it is intended to protect. The amount of slippage that is

clinically significant should also be determined. There needs to be further

research done on the lining materials for braces as skin irritation and discornfort

continue to be problems which may affect brace Wear compliance.

CONCLUSIONS

The present study indicated that the FKB Wear compliance patterns of the

ACL reconstructed patients are higher than previously reported in the AC1

deficient knee. The respondents seemed to have a good understanding of when

to Wear their FKB. There continues to be problems associated with this usage,

namely: skin irritation, slippage and buckling of the knee. Skin irritation scores

and slippage rates appear to be unacceptably high. Today's FKB's seem to be

better able to prevent knee buckling, although it is unclear if this is related to

advances in surgical technique, strengthening programs or improved

biomechanics of the brace. Overall, the respondents seemed satisfied with their

FKB and their level of performance. Most respondents decreased their activity

level by one sport after surgery, despite bracing. There were, however, 26% of

respondents who did not fiIl their FKB prescription. Patient perception of FKB

effectiveness, buckling of the knee and brace slippage al1 have an impact on the

patient's decision to Wear an FKB, although these factors independently or

combined are not strong predictions of brace wear.

CLlNlCAL SlGNlFlCANCE

Physicians should feel confident that their ACL reconstructed patients

understand when they are to Wear their FKB, and that they will Wear it 78% of

the time that they are engaged in sports considered to put their reconstruction at

risk. Financing of the FKB needs to be considered in greater detail when

discussing brace usage with patients. Off-the-shelf braces cost approximately

half that of the custom FKB. As there is little evidence supporting custom versus

off-the-shelf, it may be advisable that off-the-shelf braces are used if physicians

feel strongly that their patients adhere to FKB use post-surgically, and third

party insurance is not available. Brace slippage and skin irritation continue to

be problems associated with brace wear. FKB manufacturers need to examine

the linings, and fitting techniques used when designing braces. Patients should

be instructed that slippage may be associated with changing leg volume and

furtherkegular fittings may be required. Generally, patients were satisfied with

their level of activity (despite decreasing their participation in approximately one

sport post-surgically) and the performance of their brace. They remained

motivated to continue with their knee strengthening program on a regular basis

for approximately one and one half years.

TABLES AND FIGURES

Table 1: Mean age and standard deviation for brace and no brace groups.

Gender AGE hm)

1 8-35

FEMALE 36-65

Corn bined 1 8-65

1 8-35

MALE 36-65

Combined 18-65

MALE AND 36-65 FEMALE

Corn bined 18-65

BRACE NO BRACE GROUP

Table 2: Frequency of involved knee (WL) and brace purchase (n=77)

Gender Knee Brace No Brace

Female R 13 4

Male R 18 7

L 13 5

Male and Female R 31 11

Table 3: Frequency of responses to ltem 1 (Part a).

When you received your brace you were given instructions as to when you should Wear your brace. Please explain what your understanding is of when you should be wearing your brace.

Instructions Frequency Percent

None Given 3 5.30

All Sports 16 28.1 O

Pivotingistop-start Activities 31 54.40

Physically Active 5 8.80

Work 2 3.50

Total 57 1 00.00

Table 4: Frequency of response to ltem 1 (Part b).

What is your primary sport? Primary Sport Frequency Percent

Soccer 11 19.30

HockeylField hockey 9 15.80

Other

Volleyball

Basketball

Ski ing

Go If

Baseball 3 5.30

Racquet sports 2 3.50

Rollerblading

Football

Total 57 1 00.00

Table 5: Means and standard deviation (SD) for response to ltem 2 (cm).

How often do you Wear your brace when participating in sports that involve quick changes of direction, or require you to plant your leg and twist?

never always

AGE GENDER 1 8-35 yrs 36-65 yrs 18-65 yrs

FEMALE 6.86 (3.77) 8.71 (3.52) 7.45 (3.72) n = 17 n = 9 n = 26

MALE 7.79 (3.41) 8.36 (2.27) 7.99 (3.02) n = 20 n = l l n = 31

Table 6: Analysis of variance surnmary for ltem 2: FKB cornpliance during sport activity that requires quick changes of direction.

Source Sum of df Mean Square F Ratio Sig. Level Squares

A W 14.12 1 14.72 1.25 0.27 Gender 0.81 1 0.81 0.07 0.79

Age X Gender 7.19 1 7.19 0.64 0.43 Residual 587.65 52 11.30

Male R - - - . - .

Female - YOUNG (18-39 OLD (3ô-65)

Figure 2: Means and standard deviations (1) for FKB cornpliance during sports requiring quick changes of direction.

Table 7: Means and standard deviations (SD) for response to ltem 3 (cm).

How often do you Wear your brace when participating in your primary sport?

never always

AGE GENDER 18-35 yrs 36-65 yrs 1845 yrs

FEMALE 6.85 (3.90) 8.76 (3.38) 7.46 (3.78) n = 1 7 n = 9 n = 26

MALE

Table 8: Analysis of variance summary ltem 3: FKB cornpliance data during primary sport activity.

Source Sums of cif Mean Square F Ratio Sig. Level Squares

A W 1.29 1 1 -29 O. 09 O. 77 Gender 2.39 1 2.39 0.17 0.69

Age X Gender 30.43 1 30.43 2.1 1 0.15 Residual 751.34 52 14.45

Figure 3: Means and standard deviations (1) for FKB cornpliance in subjects primary sport.

l YOUNG (18-35) OLD (3M5)

1

-

1

i

Male m.-- . Female -


Has your level of performance in your primary sport changed from before you injured your knee?

a lot worse same

AGE GENDER 18-35 yrs 36-65 yrs 18-65 yrs

FEMALE 4.76 (3.24) 6.46 (3.63) 5.31 (3.39) n=17 n = 9 n = 26

MALE 7.03 (2.81 ) 5.93 (3.15) 6.72 (2.89) n = 20 n = l l n = 31

Table 10: Analysis of variance summary of ltem 4: performance change.


Age 0.84 1 0.84 0.09 0.77 Gender 9.81 1 9.81 1 .O2 0.32

Age X Gender 24.81 1 24.81 2.57 0.12 Residual 501.74 52 9.65

Figure 4: Means and standard deviations ( L ) for level of performance in subject's primary sport.

Table 1 1 : Frequency of responses to ltem 5.

Have you had to change the way you play your primary sport? Y e s o N o n If your answer is yes, is it by limiting your participation, changing the way you perform certain skills, or avoiding particular activities? 1 . Limit 2. Change 3. Avoid Please circle one answer.

Response Option Frequency Percent

No 19 33.3

Change method 22 38.6

Limit activity 9 15.8

Avoid activity 7 12.3

Total 57 1 O0

Table 12: Frequency of responses to ltem 6.

Overall do you think your brace has been effective in allowing you to be active? ~ e s u N o n


Yes 48 84.2

No 7 12.3

Missing* 2 3.5

Total 57 100

* Two subjects did not complete this item.

Table 13: Frequency of responses to Items 7 and 8 (most subjects participated in two or more sports) (n = 55)

ltem 7: Please check the boxes beside the sports that you participated in before your knee injury. ltem 8: Please check the boxes beside the sporüs you participate in now.

footballn basketballn vo l leyba l l~ s o c c e q lacrossen downhill skiingo cross-country skiingo hockey0 figurelspeed skatingn rollerbladinga aerobicsn racquet sportsn othern Please list if other:

Volleyball Downhill skiinglsnowboarding Racquet sports Basketball Hockey Soccer Rollerblading Aerobics Football Cross-country skiing Baseball Golf Swirnming Cycl ing RunninglHiking Water-ski ing Figure skating Martial arts Weightlifting Track and field Ringette Dance Sailing Gymnastics Rock climbing Wrestling Curling Lacrosse

Sport Participation Before Now Number of New l njury lndividuals Taking Up

Sport 29 18 O

Total 254 212 23

Table 14: Frequency of responses to Item 9.

Have you experienced any giving way or buckling of your knee during any activity, while wearina vour brace? Yeso N o n If yes, please explain how often:


Yes

No

Missing*

Total 57 1 O 0

* Five subjects that did not complete this item.


Do you experience problems with your brace slipping?

always never

AGE GENDER 18-35 yrs 36-65 yrs 18-65 yrs

FEMALE 3.63 (3.34) 5.51 (3.97) 4.23 (3.58) n = 1 7 n = 27 n = 26

MALE 4.59 (3.32) 5.62 (3.04) 4.95 (3.21) n = 20 n = 11 n = 31

Table 16: Analysis of variance summary of ltem 10: brace slippage.


&le 14.81 I 14.81 1.29 0.26 1

Gender 2.37 1 2.37 0.21 0.65 Age X Gender 7.26 1 7.26 0.63 0.43

Residual 596.61 52 1 1.47

AG€ (years)

2.

1 .

Figure 5: Means and standard deviations (1) FKB slippage.

1 Male i

l O

Fernale t------

YOUNG (18-35) OLD (36-65)

Table 17: Frequency of responses to Item 1 1

Do you experience discornfort or skin irritation as a result of wearing your brace? ~ e s n N o n


Yes

No

Total 57 I O 0

Table 18: Means and standard deviation (SD) for response to ltem 12 (cm).

Do you continue to cary out knee strengthening exercises, in addition to your other recreational activities?

not at al1 every day

AGE GENDER 18-35yrs 36-65 yrs 18-65 yrs

FEMALE 4.98 (2.82) 4.80 (3.22) 4.92 (2.89) n=17 n = 9 n = 26

MALE 4.49 (3.07) 5.75 (3.44) 4.94 (3.21) n = 20 n = Il n = 31

Table 19: Analysis of variance summary of ltem 12: compliance to a knee strengthening exercise routine.


Age 1.63 1 1.63 0.17 0.68 Gender O. 54 1 0.54 O. 06 0.81

Age X Gender 3.71 1 3.71 0.38 O. 54 Residual 51 3.26 53 9.68

Figure 6: Means and standard deviations (1) for cornpliance to knee strengthening exercises.

Table 20: Response frequency to : What is the brand name of your brace?

Brace Name* Frequency Percent

~eneration II 13 22.8

C.Ti 2 12 21.1

Don Joy Defiance 14 24.6

Air Townsend 4 7

Custom 8 14

Off-the-shelf 5 8.8

Missing 1 1.8

Total 57 1 O0

* Generation II: Generation II Orthotics, Inc. 1 1091 Hammersrnith Gate, Richmond, British Columbia

Don Joy Defiance: Smith + Nephew, Don Joy Inc. 2777 Locker Ave., Carlsbad, California

c . T ~ ~ : Innovation Sports Inc. 7 Chrysler, Irvine, California

Air Townsend: Townsend Design Inc., 461 5 Shepard St., Bakersfeld, California

Table 21: Means and standard deviations (SD) of response to question: How long have you had your current brace (months)?

Gender Age Brace (SD)

Male 22.61 (1 8.03) n = 31

Male/Female 22.80 (1 8.03) Corn bined n = 57

Table 22: Frequency of response to question: Who paid for your brace? Please check the most correct answer. ~oursel f [7 WCBO Third party insurance0 If a combination of the above, please check the appropriate boxes.


Patient 5 8.8

lnsurance 37 64.9

Patientllnsurance 11 19.3

WCBlmilitary 4 7

Total 57 I O 0

Table 23: Response to: Do you think you got good value for your money when you purchased you knee brace? Yeso NO^


Yes 43 75.4

No Il 19.3

Missing 3 5.3

Total 57 1 O0

Table 24: Prediction of brace usage (Item 2) using the following predictor variables: patient perception of effectiveness (Item 6), buckling of knee while wearing FKB (Item 9). brace slippage (Item 10) (only those items that produced a significant change in R' are shown

Variables R R Square Adjusted Std. Error R Square R Square of the Change

Estimate Effective (Yesf No) 0.52 0.27 0.26 2.79 0.27 Buckle (YeslNo) 0.59 0.35 0.32 2.67 O. 07 Slippage (VAS) 0.64 0.41 0.37 2.57 0.06

Brace use = 16.43 - 5.07(X1) - 2.36 (X2) + .25(&) Where XI = perceived effectiveness by patient (1 = yes, 2 = no)

Xz = knee buckling while wearing a brace (1 = yes, 2 = no) )G = brace slippage (0-1 0)

APPENDIX A: SAMPLE SlZE CALCULATION

AND TEST-RETEST RELIABILIW OF QUESTIONNAIRE

Appendix A: Sarnple size calculation using standard error = Ilpci/n (p = proportion that are compliant, q = proportion that are non-compliant, and n = sample size)

Value of p 0.05 0.25 0.5 0.75 0.95 0.03 0.07 0.07 O. 06 0.03 0.02 O. 04 0.05 0.04 0.02 0.02 0.03 0.04 0.03 O. 02 0.01 0.03 O. 03 0.03 O. 02 0.01 0.03 0.03 0.03 0.01 0.01 0.03 0.03 0.03 0.01 O. 0 1 0.02 0.03 0.02 0.01 0. O 1 0.02 0.03 0.02 0.01 0.01 0.02 0.02 0.02 0.01 0.01 0.02 0.02 0.02 0. O 1

Test-retest reliability of questionnaire using Pearson Product correlations (n = 6)

Item Number Pearson Product r Probability 1 .O0 1 .O0 0.000

APPENDIX B: LETTERS OF INFORMATION AND CONSENT

A Survey of Functional Knee Brace Usage Following Anterior Cruciate Ligament Reconstruction

Dear

Drs. Fowler, Kirkley, Amendola, and Litchfield. in cooperation with Dr. Kramer of the Department of Physiml Therapy, are conduding a survey of people who have had ACL reconstnictive surgery and were given a prescription for a knee brace after surgery. Our main interests are in leaming what patients think of their knee brace, and their ability to play in the sports of their choice. This research will help to study how effective patients find these braces and direct Mure research. Participation in the study is voluntary. You may refuse to participate or withdraw from the study at any time with no effect on your future care.

Did you have your prescription for a knee brace filled? ~ e s O N o n If your answer is "nonI please retum this letter in the stamped addressed envelope as this is still useful information for us. If your answer is "yes" please continue.

All information that you provide is completely confidential. The information will be coded with an identification nurnber and your name will not be released. We have tested the questionnaire and it should take no longer than ten minutes to complete. Please use the stamped, addressecl envelope to retum your questionnaire.

The questionnaire asks you to put a slash across a line indicating how you feel about a certain topic. For example:

I think the Blue Jays will win the World Series?

I no way 100% right

If you put the slash % of the way toward the 100% right side it would indicate to us that you are pretty sure that they will win, but not 100% certain. We are asking for your opinion. It is important to put your slash at either end of the line if the extrerne descriptions reflect your opinion.

If you have any questions regarding this questionnaire please feel free to contact the project co-ordinator, Anne Rankin, at 661 -3360 for help. Your participation in this survey is much appreciated.

S incerel y,

Project Co-ordinator, Anne Rankin BScPT, MSc Candidate UWO

A Suwey of Functional Knee Brace Usage Following Anterior Cruciate Ligament Reconstruction

Dear

This is a follow-up letter to the one you should have received regarding your knee brace. Drs. Fowler, Kirkley, Litchfield, Amendola, and Kramer are close to completing their data collection and still have not received your input. If you would like to have your information included in our study 1 would encourage you to fiIl in your questionnaire as soon as possible. Participation in the study is voluntary. You may refuse to participate or withdraw from the study at any time with no effect on your future care.

Did you have your prescription for a knee brace filled? ~ e s n NO^ If your answer is "no", please retum this letter in the stamped addressed envelope, as this is still useful information for us. If your answer is yes, please continue. We have included another questionnaire in case the first copy has been misplaced.

To complete the questionnaire please place a slash across the line which will best indicate your feelings on the question. For example: Do you think the Blue Jays will win the World Series?

If the slash is put in the middle of the line, this shows us that you think the Blue Jays have a 50150 chance of winning the World Series. It is important to put your slash anywhere on the line that best reflects your feelings, even if it is the extreme description.

no way

If you have any questions regarding this questionnaire please contact the project coordinator Anne Rankin, at 661-3360 for further help. Thank you in advance for taking time from your bust schedule to help in this area of research.

100% right

S incerely,

Project Coord inator Anne Rankin MSc Candidate UWO

APPENDIX C:

NOTICE OF APPROVAL FROM REVIEW BOARD FOR HEALTH SCIENCES

RESEARCH INVOLVING HUMAN SUBJECTS,

UNIVERSITY OF WESTERN ONTARIO

ALL HEALTH SCIENCES RESURCH INVOLVINC üWM SVBJeCPS AT THE UNIVERSITY OP WESTERN OHPARI0 IS CARRKED our IN COHPL~AWCB WITH me ~ D X C A L RESFARCH mutxrt OP CANADA .curomwu ON RESURCH INVOLVING HUHCLN SV&TECT..

1) Dr. 8 . Bonrein, Assis tant Dean-Rueuch - Medicine (Chairman) (Anatomy/ophthrlwlogyi 2 üs. S. Woddinott, Assistant Dirrctor OC Research Services (Epidemiology) 3 ) Dr. R, Richards, St. Joseph's Hospital Representativa (Surgery) 4 ) Dr. P. Rutledqe, Victoria Hospital Representative (Criticil Care - Hedlcine) 5 ) Dr. D. Bocking, University Hospital Representative (Physici u, - Interna1 Hediclne) 61 Dr. L. Haller, Office of the President Representative (French) 7 ) Wrs. E. Jones, Office oE the President Regresentativa (Coaiaiunity) 8) nr. H.E. Fleming, Off ice of the President Representativo (Legal) 9 ) Dr. O. Freeman, Faculty oE Medicina Regrasentitlv8 (Clinicaii 10) Dr. O. Sin, Faculty of Mediciam Reprosentative (Basic) (Epidrriiology) 11) Dr. n. 1. Kavalierr, FacuUy of Durtistry Rapresuitatlvo (üeatirtry-oral' Bioloqy) 12) Dr. M. Laschinger, Faculty of miraing Rtprasantitive (Nursing) 13) Dr. S.J. Spaulding, Faculty of Appllrd Hiilth Sciences Rapresentativr (Occup- Thrrapy 14) Dr. C. Rica, Faculty of Xinesiology Reprerentativm (Kineriology) 1s) D r . W. JChaLil, ~esearch* Institutes Representative (Endocrinology G kietabolfsr) 161 Ws. R. Yohnicki, Administrative Officer

Altemates are appointed for rrch aember.

THE REVIEn BOARD KAS EXAHlHED THZ RESZARCW PROJECP E N T I T U D I 'A survey of functional knee brace usage Lollwing anterior cruciate liqiuuent reconstruction: -

AS SUBHITTED BY: Dr. J . Kramer, Physical Therapy, Elborn Collage

. W b CONSIDERS IT TO BE ACCEPTABLE Ot( ETWICAL CROUNDS FûR R E S W C H INVOLVINC H W SUBJECTS W E R CONDITIONS OF THE UNIVERSITY'S POLICY OH RESEARCH INVOLVINC m N SUBJDCTS.

APPROVAL DATE: 15 October 1996 (ravisPd questionnrlrel

TI TLE: A? a &Y, Bessie Bomeln, Chairman

c .c . Hospital Administration

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IMAGE EVALUATION TEST TARGET (QA-3)

APPLIED A INLAGE . lnc - = 1653 East Main Street - -. - Rochester. NY 14609 USA -- -- ,., Phone: 71 6/42-0300 - = Fax: 7 1 61288-5989

O 1993. Applied Image. lnc.. All Righîs Resewed

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