RESEARCH TACKLES PROPHYLACTIC KNEE BRACING
Biomechanics Lab - Clinical Studies
During the 1997 season, prophylactic brace use by offensive linemen (offensive center, offensive guard, offensive tackle, and offensive tight end) was endorsed by the university coaching and medical team (certified athletic trainers and physicians). Certified athletic trainers instructed the subjects in proper application of the prefabricated prophylactic knee braces (DonJoy PKG-Protective Knee Guard) and compliance was monitored. Subjects used both the manufacturer's neoprene straps and elastic tape to secure braces to the lateral aspect of both lower extremities.
In the 1998 season, it was decided to provide custom-fitted functional knee braces (DonJoy Defiance) to all varsity offensive linemen and those freshmen offensive linemen receiving athletic scholarship aid. As nonscholarship student athletes progressed to their second year of participation in the football program, they were fitted with custom functional knee braces. Lineman positions were selected because anecdotal evidence and observation showed an inordinate number of injuries to offensive linemen due to other players falling across their knees.
Members of the offensive line were fitted bilaterally with custom functional knee braces by a single technician prior to the beginning of preseason conditioning drills. Each player was instructed individually in the proper application of the brace. Braces were worn for all contact practices. During each season, the sports medicine staff, including certified athletic trainers and board-certified orthopedic surgeons, monitored knee injuries. All injuries were recorded in the format of the NCAA's Injury Surveillance. After the season, the knee injuries were extracted and further classified according to the specific pathology involved and the severity of the injury.
In 1997, 20 subjects with a mean age of 249 months (20.75 years), mean body weight of 290 pounds, and average height of 74.9 inches were fitted with prefabricated prophylactic knee braces. Subjects averaged participation in 4.95 games during the study period and had 2.3 years of college football experience. All subjects wore bilateral protective knee braces in contact practice sessions and games (Table 1).
In 1998, 18 players were fitted bilaterally with custom functional knee braces. The average age was 249 months (20.75 years), mean body weight was 290 pounds, and average height was 74.6 inches. The study continued over two consecutive years, and thus many of the subjects were involved in both years' data. The average participation in games during the 1998 study period was 7.4 games with 2.2 years of experience (Table 1).
|Table 2 contains data regarding the
injuries of the 1997 and 1998 seasons. In 1997, the isolated grade II
medial collateral ligament sprain was treated aggressively with
nonsurgical care. The patient returned to activity in 30 days, missing a
total of 21 practice sessions. The grade III ACL tears were treated with
arthroscopic surgical reconstruction using patellar tendon autograft.
Both athletes were withheld from contact practice and conditioning
activities for six months.
In 1998, the two grade I medial collateral ligament sprains were treated aggressively but nonoperatively. Patients were able to return to full activity within two days of the injury.
With more and more effort being placed on controlling medical costs, athletic administrators' concern about reimbursement for professional services continues to grow. This situation must be dealt with at all levels of athletic participation, from high school and college to professional sports. With the cases presented from the 1997 and 1998 seasons, we looked at actual costs of the injuries and the impact of prophylactic bracing as a prevention tool.
Review of Table 2 reveals the economic impact of knee injury and subsequent care to offensive linemen. The actual costs of the 1997 season include two surgical reconstructions of anterior cruciate ligaments totaling $45,795. The cost of care for knee injuries in 1998 fell to $1,630, due primarily to the lack of surgical cases. The cost to provide custom fitted prophylactic knee braces to offensive linemen for this project totaled $16,200 (30 braces at $540 each). Though a significant expenditure (the prefabricated braces had cost $75 each), the staff felt the investment was very prudent-especially in terms of injury prevention, quality of life for student athletes, and further prevention of time lost from activity.
This review of the literature provides evidence of the protective aspects of prophylactic knee braces to capsular structures of the knee. Likewise, functional knee braces are found to effectively control forces of the tibia, which can produce stresses and possibly injure the capsular and/or anterior cruciate ligaments. Regarding the choice of braces, clinicians have felt that custom braces are associated with improved fit and result in less brace migration. Regardless, the chosen brace should be one that can withstand the forces of the activity, especially those selected for contact activity. At this time, I feel it is prudent to recommend bracing for prophylaxis, and this is being done at many institutions with growing popularity.
A comprehensive study of all divisions of football regarding the prophylactic nature of knee bracing needs to be undertaken. The study should track injuries relative to all brace types for prophylaxis-including the lateral protective knee guards and functional knee braces. Many institutions embrace prophylactic concepts, and further information is needed to determine the cost-to-benefit ratio for brace use. If protective knee braces are selected, the different benefits afforded by custom-fitted versus the "off-the-shelf" brace styles need to be assessed.
D. Rod Walters, DA, ATC, is assistant athletic director for sports medicine at the University of South Carolina in Columbia.
Published in Biomechanics, 712: 57-61.
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