Page 161 - Athletic Health Handbook
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Bracing of ACL injuries and in athletic performance with the use third of ACL failure loads.10
reconstructions is habit for many of braces, including measures such The question does remain, however,
surgeons and should be investigated as energy consumption,5 muscular if the brace would continue to provide
from several angles as the clinical fatigue6 as well as speed and agility.7 similar protection as forces rise
question is not completely In a position statement written to levels approaching tissue failure.
straightforward. These decisions in 1997 and retired in 2008 by The
include prophylactic bracing American Academy of Orthopaedic Proprioception is another aspect
for high risk activities, functional Surgeons, prophylactic braces were of bracing that has been well studied
bracing of the ACL deficient knee, not endorsed for routine use.8 with the premise that improved
immediate post-operative bracing, In the role of team physician, position sense would decrease recurrent
and ultimately functional bracing the recommendation for brace wear injury episodes. Wu and colleagues
during rehabilitation and return to may depend on the player’s position, investigated the sensorimotor
sport. Each is a specialized area of the level of competition, and the performance of the knee after
physician and patient concern and preferences of the player, however ACL reconstruction by comparing
one answer may not fit all patients empiric bracing is not indicated subjects treated with functional
or situations. This review attempts for prophylaxis in an otherwise knee brace, placebo knee brace, and
to assess data surrounding empiric healthy population. no brace after ACL reconstruction.
knee bracing for ACL injury and Proprioception improvements were
reconstruction to determine if any Scientific Rationale found in the brace and placebo
benefit for the patient is realized with for ACL Brace Use brace groups, which suggest that the
the continuation of this practice. benefit was not attributable to the
The biomechanical rationale for mechanical action of the functional
Prophylactic Knee Bracing functional bracing of ACL injuries brace.11 Proprioception has also been
should be understood prior to described as being improved with
Prophylactic bracing has been discussion of clinical efficacy. Does application of a simple neoprene
advocated to reduce injuries the brace perform the function that sleeve in normal subjects supporting
during activities at high risk for knee the physician anticipates when they this theory.12 In a study of ACL
ligamentous injury. The primary prescribe its use? The desired goal in reconstruction subjects a neoprene
designs of prophylactic braces include simplest terms is limitation of anterior sleeve was found to improve the
hinged single or dual uprights with translation of the tibia relative to the threshold for detection of passive
the primary goal of limiting valgus femur at the knee joint to decrease knee motion in the first year
stress to prevent the characteristic strain on the reconstructed ACL. post-operatively, however at 2 years
sequence of injury to the MCL, ACL, In turn it should allow restoration of there was no deficit in this measure
and PCL.2 Clinical studies have a symmetric gait pattern to improve regardless of bracing.13 Thus,
supported the use of prophylactic patient function. Several studies have proprioception does appear to be
bracing, including a 1990 study of been reported to help answer these affected by bracing in the short term,
1,396 West Point cadet intramural questions. A cadaver study of strain however there is likely no difference
tackle football players where the rate on collateral ligaments in an ACL in this measure between a costly
of injury in the unbraced group was deficient knee in braced and unbraced brace and simple sleeve.
more than double that of the braced conditions demonstrated decreased
group (3.4 vs. 1.5 injuries/1000 forces on the collateral ligaments With restoration of symmetric
exposures).3 A similar study of in the braced condition, indicating gait being a goal of bracing, walking
987 Big Ten varsity football players that application of a brace may add kinematics have also been investigated.
stratified by position and playing mechanical protection to the collateral Bracing has been supported on a
condition showed a trend towards ligaments and counteract anterior comparison of normal subjects, ACL
decreased MCL injuries with knee laxity.9 An in vivo study of ACL deficient, and ACL reconstructed
prophylactic bracing at all positions strain utilizing transducers implanted patients in a level ground environment,
during practice and among linemen, during arthroscopy compared braced where brace wear was found to
linebackers, and tight ends in games.4 and unbraced stresses across the knee. decrease gait asymmetry in ACL
This data is balanced by studies that This study demonstrated a protective reconstructed patients in both the
demonstrate a significant decrease effect of the brace at loads up to one sagital and coronal planes.14 Further
evaluations, including use of EMG

ACL BRACING UPDATE 161
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