Multiple Concussions Increase Odds and Rate of Lower Extremity Injury in National Collegiate Athletic Association Athletes After Return to Play

Abstract

Background: Concussion in collegiate athletics is one of the most prevalent sport-related injuries in the United States, with recent studies suggesting persistent deficits in neuromuscular control after a concussion and an associated increase in risk of lower extremity injury. Purpose: To expand on the relationship between concussion and lower extremity injury by examining the effect of multiple concussions (MC) on rate and odds of future lower extremity injury in collegiate athletes after return to play (RTP) compared with matched controls. Study Design: Cohort study; Level of evidence, 3. Methods: From 2001 to 2016, 48 National Collegiate Athletic Association Division I athletes sustaining multiple concussions at a single institution were identified. Athletes with multiple concussions (MC) were matched directly to athletes with a single concussion (SC) and to athletes with no concussion history (NC) by sex, sport, position, and games played. Incidence of, time to, and location of lower extremity injury were recorded for each group after RTP from their first reported concussion until completion of their collegiate career. Logistic regression was used to analyze odds ratios (ORs) for sustaining lower extremity injury, whereas time to injury was summarized by use of Kaplan-Meier curves and log rank test analysis. Results: The incidence of lower extremity injury after RTP was significantly greater ( P = .049) in the MC cohort (36/48, 75%) than in SC athletes (25/48 = 52%) and NC athletes (27/48 = 56%). Similarly, odds of lower extremity injury were significantly greater in the MC cohort than in SC athletes (OR, 3.00; 95% CI, 1.26-7.12; P = .01) and NC athletes (OR, 1.66; 95% CI, 1.07-2.56; P = .02). Time to lower extremity injury was significantly shorter in the MC group compared with matched controls ( P = .01). No difference was found in odds of lower extremity injury or time to lower extremity injury between SC and NC athletes. Conclusion: Collegiate athletes with MC were more likely to sustain a lower extremity injury after RTP in a shorter time frame than were the matched SC and NC athletes. This may suggest the presence of a cohort more susceptible to neuromuscular deficits after concussion or more injury prone due to player behavior, and it may imply the need for more stringent RTP protocols for athletes experiencing MC.

<p>Evaluation of Musculoskeletal Re-Injury Occurrence in Previously Concussed National Football League Athletes</p>

“…Although there is previous research suggesting greater risk of MSK injury when an athlete returns to play after sustaining a SRC, 6,8,11 the current study provides insight into the conditional occurrence of MSK injury acutely following SRC in a professional athlete cohort. These results are consistent with previous studies in collegiate populations.…”

“…Previous research has examined the impact of SRC on risk of re-injury in collegiate athletics, [6][7][8] yet few have examined the potential for this risk in NFL athletes. 11 Our findings suggest NFL athletes are more likely to sustain a MSK injury within the 12-week period following RTP from an SRC, relative to a non-injured control.…”

“…These results are consistent with previous studies in collegiate populations. [6][7][8] Brooks et al reported a 2.48-fold increased risk of acute lower extremity MSK injury among recently concussed collegiate athletes across seven different sports compared to controls. 6 Further, Herman et al reported collegiate athletes, across numerous sports, were at a 3.79 times greater risk of lower extremity MSK injury in the 90-days following RTP from SRC.…”

“…5 More recent investigations have suggested secondary sports-related concussion (SRC) effects, including increased musculoskeletal (MSK) injury risk following acute SRC resolution. [6][7][8] The biological underpinnings of increased injury rates post-SRC are not clear, but collegiate athletes, across numerous sports, had an increased odds of MSK injury in the 90-day period after return to play from a SRC compared to matched controls. 6,7 Recently, Harada et al investigated the relationship between SRC and lower extremity injury risk over a 16-year timeframe in Division I collegiate athletes.…”

“…Researchers concluded those who sustained multiple SRCs were three times more likely to sustain lower extremity injuries compared to those who sustained a single concussion and healthy controls. 8 Despite previous work suggesting an increased risk for MSK injury following SRC in collegiate athlete populations, [6][7][8] how these effects may influence professional football athletes is less clear. Since National Football League (NFL) athletes participate in a longer competitive season compared to their collegiate counterparts (17 weeks versus 10-13 weeks, respectively) it follows that the number of athlete exposures also increases for professional athletes.…”