Table 3. .
Knee-Sprain Counts and Rates by Specific Diagnosis in Youth, High School, and Collegiate Football Players, 2012 Through 2014 Seasons
| Level of Play |
Injuries, No. (%) |
Injury Rate per 1000 Athlete-Exposures (95% Confidence Interval) |
Injuries Requiring Surgery, %c |
Recurrent Injuries, %c |
||
| All Injuries |
Time-Loss Injuriesa |
Severe Injuriesb |
||||
| Youth | ||||||
| MCL | 15 (45.5) | 0.07 (0.04, 0.11) | 0.03 (0.01, 0.06) | 0.01 (0.00, 0.03) | 0.0 | 6.7 |
| LCL | 12 (36.4) | 0.06 (0.02, 0.09) | 0.03 (0.01, 0.05) | 0.00 | 0.0 | 0.0 |
| ACL | 2 (6.1) | 0.01 (0.00, 0.02) | <0.01 (0.00, 0.01) | <0.01 (0.00, 0.01) | — | — |
| PCL | 1 (3.0) | <0.01 (0.00, 0.01) | <0.01 (0.00, 0.01) | 0.00 | — | — |
| Cap | 3 (9.1) | 0.01 (0.00, 0.03) | 0.01 (0.00, 0.02) | 0.00 | — | — |
| Total | 33 (100.0) | 0.16 (0.10, 0.21) | 0.08 (0.04, 0.12) | 0.02 (0.00, 0.04) | 3.0 | 3.0 |
| High school | ||||||
| MCL | 144 (46.0) | 0.12 (0.10, 0.14) | 0.09 (0.07, 0.11)d | 0.03 (0.02, 0.04) | 3.5 | 3.5 |
| LCL | 45 (14.4) | 0.04 (0.03, 0.05) | 0.02 (0.01, 0.03) | <0.01 (0.00, 0.01) | 4.4 | 8.9 |
| ACL | 98 (31.3) | 0.08 (0.06, 0.10)d | 0.05 (0.04, 0.06)d | 0.04 (0.03, 0.06)d | 33.7 | 4.1 |
| PCL | 19 (6.1) | 0.02 (0.01, 0.02) | 0.01 (0.00, 0.01) | 0.00 | 5.3 | 0.0 |
| Cap | 7 (2.2) | 0.01 (0.00, 0.01) | 0.01 (0.00, 0.01) | 0.00 | 0.0 | 14.3 |
| Total | 313 (100.0) | 0.25 (0.23, 0.28)d | 0.18 (0.15, 0.20)d | 0.08 (0.07, 0.10)d | 13.1 | 4.5 |
| Collegiate | ||||||
| MCL | 230 (61.5) | 0.43 (0.37, 0.48)e,f | 0.27 (0.23, 0.32)e,f | 0.09 (0.06, 0.11)e,f | 4.8 | 8.3 |
| LCL | 21 (5.6) | 0.04 (0.02, 0.06) | 0.03 (0.02, 0.04) | 0.01 (0.00, 0.02) | 9.5 | 4.8 |
| ACL | 83 (22.2) | 0.15 (0.12, 0.19)e,f | 0.14 (0.11, 0.17)e,f | 0.13 (0.10, 0.16)e,f | 85.5e | 7.2 |
| PCL | 26 (7.0) | 0.05 (0.03, 0.07)e,f | 0.04 (0.03, 0.06)e,f | 0.02 (0.01, 0.03)e | 7.7 | 11.5 |
| Cap | 14 (3.7) | 0.03 (0.01, 0.04)e | 0.02 (0.01, 0.03)e | <0.01 (0.00, 0.01) | 7.1 | 0.0 |
| Total | 374 (100.0) | 0.69 (0.62, 0.76)e,f | 0.51 (0.45, 0.57)e,f | 0.26 (0.21, 0.30)e,f | 23.3e,f | 7.8 |
Abbreviations: ACL, anterior cruciate ligament; Cap, capsular sprain; LCL, lateral collateral ligament; MCL, medial collateral ligament; PCL, posterior cruciate ligament.
Defined as resulting in participation-restriction time of at least 24 hours.
Defined as resulting in participation-restriction time of more than 21 days.
Not computed for counts <5.
High school estimate greater than youth estimate (injury rate ratio [IRR] > 1.00 for rates, injury proportion ratio [IPR] > 1.00 for percentages).
Collegiate estimate greater than high school estimate (IRR > 1.00 for rates, IPR > 1.00 for percentages).
Collegiate estimate greater than youth estimate (IRR > 1.00 for rates, IPR > 1.00 for percentages).