TABLE 4.
MRI Data on the 12 Little League Players With Any Postseason MRI Abnormalitya
| Abnormal MRI Finding | ||||
|---|---|---|---|---|
| Study Data | Study Variables | No (n = 13) | Yes (n = 12) | P Value |
| Preseason | Pitcher/catcher, % | 38 | 58 | .08 |
| Year-round play, % | 54 | 83 | .002b | |
| Private coach, % | 15 | 42 | .07 | |
| In season | Games played, median (range) | 29 (26-29) | 26 (24-29) | .204 |
| Innings pitched, mean ± SD | 12 ± 14 | 20 ± 17 | .252 | |
| No. of pitches, mean ± SD | 230 ± 262 | 377 ± 320 | .231 | |
| Pitchers throwing curveballs/sliders? % | 54 | 64 | .69 | |
| Postseason | Any arm pain self-report, % | 23 | 36 | .66 |
| Shoulder pain self-report, % | 15 | 18 | .9 | |
| Elbow pain self-report, % | 23 | 18 | .99 | |
| ROM (dominant-to-nondominant difference) | Internal rotation postseason (shoulder), mean ± SD, deg | −14 ± 15 | −19 ± 15 | .41 |
| Internal rotation change, mean ± SD, deg | 11 ± 13 | 14 ± 14 | .58 | |
| External rotation postseason (shoulder), mean ± SD, deg | 8 ± 12 | 2.3 ± 10 | .245 | |
| External rotation change, mean ± SD, deg | −4 ± 14 | 3 ± 13 | .266 | |
| Arc of motion postseason (shoulder), mean ± SD, deg | −6 ± 18 | −17 ± 14 | .115 | |
| Arc of motion change, mean ± SD, deg | 7 ± 16 | 17 ± 20 | .21 | |
| Elbow flexion postseason, mean ± SD, deg | −2 ± 5 | −3 ± 4 | .721 | |
| Elbow flexion change, mean ± SD, deg | 2 ± 5 | −1 ± 7 | .37 | |
| Elbow extension postseason, mean ± SD, deg | 2 ± 3 | 0.4 ± 3 | .17 | |
| Elbow extension change, mean ± SD, deg | −2 ± 3 | −1 ± 3 | .418 | |
| Pronation postseason, mean ± SD, deg | −2 ± 5 | 1 ± 8 | .395 | |
| Pronation change, mean ± SD, deg | 2 ± 7 | −0.25 ± 7 | .4 | |
| Supination postseason, mean ± SD, deg | 2 ± 6 | 1 ± 3 | .659 | |
| Supination change, mean ± SD, deg | 0.5 ±10 | 0.6 ± 5 | .979 | |
| Other postseason examination | Tenderness to palpation of shoulder in dominant arm only, % | 17 | 8 | .54 |
| Tenderness to palpation of elbow in dominant arm only, % | 17 | 8 | .54 | |
| Ulnar nerve subluxation dominant arm only, % | 8 | 8 | .99 | |
| Carrying angle side-to-side difference, mean ± SD | −0.4 ± 2 | −0.08 ± 3 | .729 | |
| Humeral retrotorsion (side-to-side difference, assessed by ultrasound), mean ± SD | −6 ± 7 | −2 ± 9 | .24 | |
| MRI quantitative data | UCL thickness postseason, mean ± SD, mm | 1.3 ± 0.4 | 1.5 ± 0.5 | .36 |
| UCL thickness change, mean ± SD, mm | 0.06 ± 0.3 | 0.08 ± 0.5 | .91 | |
| Distance UCL to ME physis postseason, mean ± SD, mm | 4.6 ± 2 | 4.1 ± 1 | .44 | |
| Distance UCL to ME physis change, mean ± SD, mm | −0.5 ± 0.6 | −0.2 ± 1.4 | .47 | |
| Distal physeal humeral width postseason, mean ± SD, mm | 2.2 ± 0.6 | 2.4 ± 0.5 | .47 | |
| Distal physeal humeral width change, mean ± SD, mm | 0.8 ± 0.7 | 0.7 ± 0.6 | .62 | |
aME, medial epicondyle; MRI, magnetic resonance imaging; ROM, range of motion; UCL, ulnar collateral ligament.
bStatistically significant.