Management of Chronic Lateral Ankle
Instability for the Athlete
William J. Barringer, C.O.
Gary S. Trexier, C.O.
Richard V. Lux, C.O.
Introduction
Chronic lateral ankle instability is a common problem with many athletes. This injury occurs in athletes of all ages and levels of
competition. A review of current orthopedic
literature indicates there is much discussion
of the conservative, non-operative treatment
of acute ankle sprains, but alternatives for
conservative management of chronic instability are almost non-existent.2,3,4,7,8
Although scientific studies demonstrating
the efficacy of non-operative treatment for
chronic instability are not available, there
are suggestions for conservative treatment of
acute instability. These methods include:
taping techniques, the Boston Ankle Stabilizer (Physical Support Systems, Boston,
MA), several types of canvas or elastic ankle
supports, the Air-Stirrup (Aircast Corp.,
Summit, NJ), the orthoplast stirrup advocated by Stover and combining casting material
and a plastic heel as described by Henning.
As noted above, the studies that describe
these orthotic techniques have demonstrated
their usefulness for the athlete with an acute
ankle injury.1 Good results were reported in
returning the athlete to competition after
proper rehabilitation and orthotic intervention.
This study concerns itself with the patient
disabled by chronic lateral ankle instability.
The ankle stabilizing orthosis was designed
to treat chronic instability for the athlete
who is not a surgical candidate, has failed in
one of the aforementioned orthoses or does
not want to retire from sports because of
recurring injury (Figure 1)
.
This method of treatment was designed to
provide a definitive orthosis that would protect against extremes of inversion and eversion yet permit free plantarflexion and dorsiflexion during competition (Figure 2)
. Consideration was given to comfort, the fit of the
orthosis in the shoe and the restriction of
mobility for the sake of stability.
Methods and Materials
From 1982 through 1987, 81 patients with
87 lateral ankle injuries were seen at The
University of Oklahoma Health Sciences
Center, section on orthotics. Of these patients, 68 were referred because of ankle
sprain (chronic and acute) and 13 were seen
for post-ankle reconstruction for management and rehabilitation. It was recommended that these 81 patients be treated with the
polypropylene ankle stabilizing orthosis, but
for the purposes of this study, only the 68
non-surgical patients were included. These
68 patients later had 74 ankle sprains.
All 68 patients were involved in athletic
competition when their injury occurred, and
they planned to resume coming upon successful treatment (Figure 3)
. Fifty-seven, or
77 percent, were chronic sprains where patients had experienced several episodes of
ankle sprain which prevented them from active participation in their sport. Seventeen or
23 percent were acute sprains. The group of
patients with acute injuries was fitted with
the ankle stabilizing orthosis after the acute
symptoms subsided.
Those patients with one time only, acute
sprains were eliminated from the study;
however, all 81 patients were sent a questionnaire. Of the 81 patients in the group, 52
responded: 30 patients with chronic instability, 15 patients with acute sprains and seven
post-operative patients. For this study, 30
out of 52, or 58 percent, who returned their
questionnaire had chronic ankle sprains and
were eligible to be included in the study. The
authors felt the most efficient method to determine the efficacy of treatment would be to
elicit the testimony of patients as to how well
the orthosis performed under competitive
conditions.
The study group consisted of 22 males and
eight females, ranging in age from 10 to 46
years (average age 19.7 years). Follow-up
ranged from three months to five years. To
be included in the study, the athlete needed
only to complete one full season of his or her
particular sport.
Results
A good result was defined as utilization of
the orthosis throughout one complete season
without any new episodes of ankle sprain or
mechanical problems with the orthosis
(breakage, severe discomfort, or restriction
of mobility). Poor results were those not
meeting the above criteria. For the purposes
of this study, all three subgroups (chronic,
acute, post-operative) were evaluated separately.
In the chronic group, 23 patients out of the
30, or 77 percent, had a good result. These
patients did not suffer further ankle sprains
and were able to participate at their maximum ability. Many in this group utilized the
orthosis for other sports and recreational activities. The athletes were seen for minor
adjustments (replacement of Velcro or padding) and modification for minor skin irritations.
Seven of the 30, or 23 percent, had poor
results. Four of the 7 did not return after the
initial fitting for fine adjustment. Our protocol dictates that after usage at one practice or
session the athlete should return for necessary modifications. Game conditions are certainly different than office conditions. Two
patients experienced severe discomfort, and
the orthosis was deemed a failure. Repeated
attempts were made at modification and refitting and all were unsuccessful. One patient, a defensive back for a local college,
stated the orthosis was protective; however,
he felt too restricted while making the necessary cuts demanded by his position. Although there were seven failures, the
authors feel that the group of four who did
not return for adjustment of the orthosis immediately after fitting and practice could
have been successful if these patients had
followed the suggested protocol.
Fabrication
The ankle stabilizing orthosis utilizes 4
mm polypropylene plastic for fabrication. It
is vacuum-formed over a cast that has two
special modifications.
The area over the lateral malleolus is modified to allow clearance and incorporates the
use of an articulated ankle joint. This step is
completed by using a concave plastic wheelchair hubcap. Next, the medial side is modified with plaster to the height of the medial
malleolus. The modification extends slightly
anterior and posterior of the apex of the medial malleolus.
The final step involves the vacuum-forming process. Since an overlapping articulated
ankle joint is needed, it is necessary to vacuum form the orthosis twice, once for the foot
section, and once for the lateral extension
and ankle joint.
Discussion
How often athletes participating in organized sport or recreational sport experience
chronic lateral ankle instability is unknown.
As our involvement in sports medicine progressed, we realized that this group of patients was larger than expected.
It became our problem to develop an orthosis that met the needs of the athlete, yet
provided a functional and reliable method of
orthotic treatment (Figure 4)
. The development of the ankle stabilizer grew out of this
need.
The authors believe that this orthotic alternative has demonstrated its efficacy as a
treatment protocol and can be an integral
part of a sports medicine program with an
attending orthotist. This orthosis cannot be
successful without the services of a certified
orthotist since others lack the technical and
clinical expertise for successful evaluation,
fabrication and fitting (Figure 5)
.
In our hands, the ankle stabilizer has been
successful and versatile; however, more in-depth study needs to follow our experience.
William J. Barringer, C.O., is the Chief Orthotist at the University of Oklahoma Health Science
Center. He is also an Assistant Professor in the
Department of Orthopaedic Surgery and Rehabilitation.
Gary S. Trexler, C.O., is the Senior Clinical
Orthotist at the University of Oklahoma Health
Science Center. He is also a Clinical Instructor in
the Department of Orthopaedic Surgery and Rehabilitation.
Richard V. Lux, C.O., is in private practice in
Springfield, Missouri. He previously was an Orthotic Resident at the University of Oklahoma
Health Science Center.
References:
- Garrick, J.G. and R.K. Requa, "Role of External Support in the Prevention of Ankle
Sprains," Medical Science and Sports, 5,1973, pp.
200-203.
- Henning, C.E. and L.N. Egge, "Cast Brace
Treatment of Acute Unstable Lateral Ankle
Sprains," American Journal of Sports Medicine,
5, 1977, pp. 252-255.
- Jackson, J.P. and M. A. Hutson, "Cast-Brace
Treatment of Ankle Sprains," Injury, 17, 1986,
pp. 251-255.
- MacCartee, C.C., "Taping Treatment of Severe Inversion Sprains of the Ankle," American
Journal of Sports Medicine, 5, 1977, pp. 246-247.
- Polakoff, D.R., S.M. Pearch, D.P. Grogan
and W.Z. Burkhead, "The Orthotic Treatment of
Stable Ankle Fractures," Orthopedics, 7, 1984,
pp. 1712-1715.
- Schuberth, J.M., et al., "A Semirigid Ankle
Brace for Chronic Ankle Instability," Journal of
American Podiatry Association, 72, 1982, pp. 611616.
- Stover, C.N., "The Air Stirrup Management
of Ankle Injuries in the Athlete," American Journal of Sports Medicine, 8,1980, 360-365.
- Stover, C.N., "A Functional Semirigid Support System for Ankle Injuries," Physician Sports
Medicine, 7, 1979, pp. 71-78.
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