Outcomes Forum: Clinical Outcomes of an Orthopedic Ankle-Stabilizing Boot

[Guest guest]

(Note: my orthotist co-authored this. I do not have the boots, nor do I

have any financial interest in them. This is just for your information if you

need ankle stabilization. Stefan, my orthotist is at http://swissbalance.com

~ Gretchen

Outcomes Forum: Clinical Outcomes of an Orthopedic Ankle-Stabilizing Boot

A. Polliack, PhD, MIPEM

Stefan Moser, CPed, CPO

ABSTRACT

The emphasis for orthotic treatment of the foot and ankle following injury

has shifted from complete immobilization to allowing functional activity to

occur in stable planes. The literature supports this concept of orthotic

treatment where tolerable flexibility and normal function with conservative

intervention will best lead to a favorable clinical outcome. Specifically, the

use of orthopedic ankle-support boots in treating acute and chronic ankle injury

has not been studied adequately to date.

In a retrospective study, 180 patients were surveyed who had been fitted

with orthopedic ankle-support boots between 1991-1996 following acute and

chronic foot and ankle injury. The boots comprise unique features, including

medial and lateral stabilizers, firm reinforced heel cups, a patented lacing

system, and torsion-resistant sole design. Clinical outcomes were obtained from

a survey mailed to patients. An 18% return rate (33 patients) was achieved.

Results indicated that 42% of patients were prescribed the boots to replace an

existing orthosis, while 29% claimed that the boots were prescribed to avoid

surgery. Eighty-six percent of subjects were able to resume their normal

activities immediately once fitted. Only 13% of all subjects had surgical

intervention following use of the boots. A high level of compliance was

achieved; 86% were still wearing the boots at the time of survey and 77% would

prefer the same treatment again.

The study indicated positive clinical outcomes with the use of orthopedic

ankle-support boots as demonstrated by a speedy return to normal activities;

reduced time on disability; its application in acute, chronic, and prophylactic

stages; its favorable response over other commonly used modalities; and a high

level of compliance.

Key Words: Ankle-Support Boots; Ankle Bracing; Ankle Immobilization;

Orthosis; Ankle Injury; Talofibular Injury.

Introduction

Talofibular joint injuries are the most frequent injuries to the foot

mechanism. However, there are no commonly accepted parameters in treating such

injuries (1,2). In recent years, the emphasis for the use of foot and ankle

bracing has shifted from complete immobilization to providing support in only

the unstable planes while allowing functional activity to occur in stable

planes. Research has demonstrated that proprioception can be impaired after

immobilization of the ankle (3,4), and atrophy of the leg muscles may occur (5).

Buschbacher (1) stated that immobilization is seldom necessary and useful.

Rather, stable mobilization of the unstable joint is desired. and Frenyo

(2) observed the advantages of flexibility and normal function with conservative

versus surgical intervention and immobilization of foot ligament injuries.

Specifically, the use of orthopedic ankle-stabilizing boots to treat acute

foot ankle injury, chronic foot and ankle instability, and foot and ankle

fractures, and to prevent foot and ankle reinjury has not been studied

adequately to date (1). The single publication in this area was that by

Hintermann et al. (6), who performed a prospective study on 46 patients with

fresh ruptures of the lateral ligaments of the ankle. Twenty-eight patients were

fitted with the Ortho Rehab ankle-stabilizing boot (Künzli & Co., Windisch,

Switzerland) in lieu of casting. Surgical intervention was performed on 18

patients whose lateral varus subluxation tilt exceeded 12 degrees. Treatment

consisted of six weeks of taping and concurrent use of the Ortho Rehab

ankle-stabilizing boot. Range-of-motion tests were performed at two and 12

months postinjury. Results at two months and 12 months postinjury showed

excellent mechanical and functional stability. Patients returned to routine

activities sooner than was achieved with either a plaster of Paris cast or an

Aircast Stirrup®(7,8).

This study presents findings of a retrospective study to assess clinical

outcomes following the use of orthopedic ankle-stabilizing boots with 180

patients who presented with instabilities and other symptomatic disorders of the

foot and ankle.

Methodology

A 16-question survey was sent to 180 patients who were fitted with Künzli

Orthopedic Ankle-Support boots (Künzli & Co., Windisch, Switzerland) between

1991-1996 (Figure 1) . All patients were referred by orthopedic surgeons or

primary care physicians. Clinical outcomes were obtained in the survey by

obtaining information on mechanical and functional stability, compliance, injury

sustained, and time to resume normal activity, among other questions (Figure 1)

.. Patients were fitted with one of eight boot models. All of the eight models

fitted are comprised of the following four generic features (Figure 2) :

1.. " A-Principle " dual medial and lateral removable stabilizers or stays

that maintain stability in the ML plane while allowing dorsi- and

plantarflexion. The plastic stabilizers are comprised of two types of stiffness

grades: polyester (rigid) and nylon (semi-rigid). Both grades of stays are

thermomoldable and are easily interchangeable.

2.. A firm, reinforced heel cup of cardboard-leather combination that

has been solidified with a bonding solution.

3.. A lacing system (patented in 1959) with nylon webbing that inserts

distally at the plantar aspect of the boot, providing an even distribution of

instep pressure over the entire dorsal aspect of the foot. At the proximal end

are " D-shaped " eyelets made from one-piece, punched-out, sheath metal.

4.. " Sandwich construction " intermediate sole design that is

torsion-resistant in the medial-lateral plane with flexibility in the

anterior-posterior plane.

All patients were fitted with one of eight Künzli boot models. The Ortho

White, Ortho Black, Ortho Rehab, Ortho Rehab Air, and Ortho Open models have

waffle soles (Figure 3) . Safari Plus, Rocky Plus, and Rocky High have

perforated soles indicated for industrial and outdoor activities (Figures 4 , 5

). Ortho White differs from the Ortho Black in color only.

The Ortho Rehab and Ortho Rehab Air model differ only inasmuch as the

Ortho Rehab Air comprises dorsal perforations for better heat dissipation. The

Ortho Rehab and Ortho Rehab Air models are the most rigid of the eight models

fitted. They feature an additional and extended heel cup reinforcement with

longer medial and lateral stabilizers. Both were designed initially to be used

in lieu of a cast. The Ortho Rehab was also the model used in the study

performed by Hintermann et al. (6).

The Ortho Open is similar to the Ortho White and Black models but has

Velcro closures. This is indicated for patients who cannot fit into the other

models as a result of foot deformities such as hammer toes, a large instep area,

or the inability to plantarflex their feet for insertion.

The Safari Plus and Rocky Plus models are similar except for their

cosmetic designs and are indicated for industrial and outdoor use. The Rocky

High is four inches higher over the lower calf section, but is otherwise similar

to the Rocky Plus and Safari Plus models.

Results

The survey return rate achieved was 18% or 33 patients (67% male, 33%

female; mean age 51.6 ± 16.7 years). Only surveys that were completed in full

were counted as a return. Of the type of model used, 51% of patients were fitted

with the waffle-type sole while 49% were fitted with the perforated sole (Figure

6) . At the time of the study, 50% of patients had been using their orthopedic

ankle-support boots longer than two years, 19% longer than three years.

Twenty-three percent of respondents utilized the boots exclusively for work, 25%

exclusively for sport, and 52% for everyday activities, including work and

sport. Etiology of injury showed that 31% of subjects sustained falls, 19%

twisted their ankle, 7% slipped, and the remaining 43% had other reasons, e.g.,

due to Charcot Marie Tooth disease, polio, traumatic compression injuries, or

rheumatoid arthritis. The orthopedic ankle-support boots were prescribed

following ankle sprain and strain (20%), rupture of ankle tendons or ligaments

(43%) or following open reduction, internal fixation of fractures (23%) (Figure

7) . Fifty-four percent of the subjects found wearing the boots " very

comfortable, " 33% found them " comfortable, " while 13% found them

" uncomfortable. " Forty-two percent of respondents stated that the boots were

prescribed to replace an orthosis (Figure 8) . Twenty-seven percent of all

subjects had full recovery or healing from their foot and ankle injury as a

result of wearing the boot, although most continued to wear them as a

prophylactic measure. Thirty percent of respondents claimed the boots were

prescribed in lieu of foot and ankle surgery. Only 13% of subjects underwent

surgical intervention after being fitted with the boots. Of the 87% of subjects

who did not undergo surgery while utilizing the boots, 44% felt that the boots

directly aided in preventing surgery. Other results showed that 86% of the

subjects were able to resume their usual activities immediately following use of

the boots. At the time of the survey, 87% of respondents were still wearing the

boots daily. Seventy-seven percent of the subjects would prefer the same

treatment again.

Discussion

This study of 33 subjects indicates positive clinical outcomes with

utilization of the orthopedic ankle-support boots. Most boots were indicated for

chronic use. More than half of all subjects had used their boots for over two

years, and a fifth of all subjects for over three years. This result indicates

that the boots are durable; they usually require resoling or other leather work

on an as-needed basis only. This is more impressive in light of the fact that

most of these patients were fitted with only one pair of boots, for which they

performed all daily activities of work and recreation. The authors postulate

that there was good patient compliance, a claim substantiated by the finding

that 87% of respondents still utilize their boots daily, and that 77% would

prefer the same treatment again. At the end of the survey, patients had the

option of commenting on positive and negative aspects of the Künzli Orthopedic

Ankle-Support boots. Positive aspects included ankle stability, excellent

comfort, boot quality construction, cosmetic appearance, style options, support

on uneven terrain, and the ability to accommodate custom-made foot orthoses.

Negative aspects included weight, stiffness, the lack of a model with a steel

toe, only one width option, and donning time.

About two-thirds of injuries were soft-tissue related, with the remaining

patients sustaining bone or joint fractures. Of the soft tissue injuries,

two-thirds involved a rupture of ligaments or tendons. It is evident that most

patients in this study sustained significant trauma to the foot and ankle.

Forty-two percent of the subjects stated they were prescribed the orthopedic

ankle-support boots to replace other orthoses that were being used at that time

(Figure 8) .

The results of the study demonstrate that use of the Künzli Orthopedic

Support boots met with high patient compliance, provided support and comfort

adequate enough for patients to resume immediately their usual activities

(barring sports activities), and subsequently led to a very low proportion of

patients requiring foot and ankle surgery. The retail cost of the eight models

ranges from $300-$500. In light of the results of the study, the Künzli

Orthopedic Ankle-Support boot has demonstrated its ability to provide an

improvement in patients' quality-of-life and a cost-effective orthotic option

for foot and ankle injuries.

Indications

Indications for using the orthopedic ankle-support boots include:

a.. semi- and complicated cases of soft tissue injuries of the foot and

ankle (muscle, tendon, and ligament);

b.. in lieu of casting and other commonly used orthotic/orthopedic

modalities;

c.. following operative treatments of strains, sprains, ruptures, and

fractures of the foot and ankle.

Conclusion

This retrospective study on 33 subjects reported clinical outcomes with

the use of an orthopedic ankle-support boot. Examination of the results showed

that patients achieved the following with the use of Künzli Orthopedic

Ankle-Support boots:

a.. a speedy recovery to normal activities

b.. reduced time on disability

c.. a cost-effective form of treatment

d.. continuous use in acute, chronic, and prophylactic stages

e.. a favorable response over other commonly used modalities

f.. sufficient mechanical and functional stability

g.. a high degree of compliance.

Disclosure: Künzli Orthopedic Ankle-Support boots are manufactured by

Künzli & Co. (Windisch, Switzerland) and distributed in North America and the

Caribbean by Swiss International, Inc. (Hollywood, Florida). Swiss Balance, Inc.

has no business or financial interest with either Künzli & Co. or Swiss

International.

References:

1.. Buschbacher RM. 1994. Ankle sprain evaluation and bracing. In Sports

medicine and rehabilitation: a sports-specific approach, Eds. Buschbacher RM and

Braddom RL. Philadelphia: Hanley & Belfus, Inc.

2.. G, Frenyo A. Acute rupture of the lateral ligaments of the

ankle-to suture or not to suture? Journal of Bone and Joint Surgery 1984; 66B:

209-212.

3.. Freeman MAR, Dean MRE, Hanham IWF. The etiology and prevention of

functional instability of the foot. Journal of Bone and Joint Surgery 1965; 47B:

678-685.

4.. Kannus P, Renstrom P. Treatment for acute tears of the lateral

ligaments of the ankle; operation, cast, or early controlled mobilization.

Journal of Bone and Joint Surgery 1991; 73A: 305-312.

5.. JA, Strizak AM, Veras G. A study of thigh muscle weakness

in different pathological states of the lower extremity. American Journal of

Sports Medicine 1976;13:1:241-248.

6.. Hintermann B, Holzach P, Matter P. Treatment of fibular ligament

rupture with the Ortho Rehab shoe. Swiss Sports Medicine Journal 1990;38:87-93.

7.. Fritschy D, Junet C, Bonvin J. Funktionelle Behandlung von

Aussenbandlasionen am oberen Sprunggelenk. Journal of Traumatology in Sport

1987;4:131-136.

8.. Raemy H, Jakob R. Die Funktionelle Behandlung der frischen fibularen

Bandlasion mit der Aircast-Schiene. Swiss Sports Medicine Journal 1983;31:53-57.

JPO 1998 Vol. 10, Num. 2 pp. 37-41