APPENDIX Table A1.
Studies Included in Assessment of Competitive Outcomesa
| Lead Author (Year) | Participants | Outcome Measures | Major Results | STROBE Scoreb |
|---|---|---|---|---|
| Erickson14 (2019) | 292 MLB + MiLB pitchers with primary UCLR | Strikeouts, hits, walks, home runs, FIP, pitching WAR, ERA, IP, WHIP | Both hamstring and palmaris autograft groups showed performance declines in WAR (0.86 [before UCLR] vs 0.35 [after UCLR] and 1.23 vs 0.34, respectively) and WHIP (1.33 vs 1.44, respectively, and 1.36 vs 1.51, respectively). IP (87.50 vs 68.01, respectively, and 88.42 vs 61.31, respectively) and counting statistics decreased postoperatively. FIP did not decline postoperatively (4.56 vs 5.27, respectively, and 4.51 vs 4.53, respectively). | 20 |
| Erickson16 (2014) | MLB pitchers with primary UCLR: 179 for RTP analysis + 148 for competitive analysis | ERA, IP, hits, walks, strikeouts, WHIP | Performance declined significantly the year before UCLR (ERA: 7.31; WHIP: 1.79) compared with the year after UCLR (ERA: 3.85; WHIP: 1.35). For the following 3 y after surgery, pitchers with UCLR (ERA: 4.18 ± 1.36; WHIP: 1.39 ± 0.25; hits per inning: 1.01 ± 0.24) performed better than did controls (ERA: 6.36 ± 3.31; WHIP: 1.70 ± 0.46; hits per inning: 1.17 ± 0.34). | 22 |
| Erickson15 (2016) | MLB pitchers: 135 with primary UCLR + 19 with revision UCLR | IP, No. of pitches thrown | There were no differences in IP the season after UCLR or IP during the career after UCLR between pitchers who underwent revision UCLR and those who did not. Also, there were no differences in No. of pitches thrown the season after UCLR or No. of pitches thrown during the career after UCLR. | 18 |
| Gibson23 (2007) | MLB pitchers: 68 with primary UCLR + 112 controls | ERA, WHIP, IP | IP significantly decreased from 97.10 innings the year before surgery to 70.17 innings the year after surgery. ERA and WHIP did not significantly differ, with ERA increasing from 4.12 to 4.21 and WHIP decreasing from 1.362 to 1.356. Controls had a comparable decrease in IP and no change in ERA and WHIP. | 17 |
| Jiang28 (2014) | MLB pitchers with primary UCLR: 38 for RTP analysis + 28 for competitive analysis | ERA, IP, pitch velocity | Fastball pitch velocity decreased significantly every year after surgery (before surgery: 91.5 mph; 1 y after surgery: 89.7 mph; 2 y after surgery: 88.7 mph; 3 y after surgery: 87.7 mph). However, changes in pitch velocity did not differ between pitchers with UCLR and controls. There were no differences in performance measures, such as ERA, BAA, or WHIP, between pitchers with UCLR and controls. | 20 |
| Keller31 (2016) | MLB pitchers: 83 with primary UCLR + 83 controls | Pitch velocity, pitch usage (%), IP | Pitchers with UCLR pitched fastballs significantly more often than did controls (46.7% vs 39.4%, respectively); however, curveball, slider, and changeup usage did not differ. All pitch velocities, as well as IP, before surgery did not differ between pitchers with UCLR and controls. | 17 |
| Keller34 (2014) | MLB pitchers: 168 with primary UCLR + 178 controls | ERA, WHIP, IP | ERA (4.15 vs 4.74, respectively), WHIP (1.40 vs 1.48, respectively), and IP (59.81 vs 50.28, respectively) worsened significantly from before to after UCLR. Performance the year before surgery was significantly worse than performance before and after that year. | 19 |
| Lansdown35 (2014) | 80 MLB pitchers with primary UCLR | Walks, strikeouts, FIP, WAR, ERA, IP, WHIP, pitch velocity, pitch usage (%) | Fastball pitch velocity (91.3 mph vs 90.6 mph, respectively), fastball usage (64.8% vs 60.4%, respectively), and IP (83.0 vs 57.3, respectively) significantly decreased from before to after UCLR. Curveball, changeup, and slider velocity, as well as ERA, WHIP, and FIP, did not differ from before to after UCLR. | 18 |
| Makhni39 (2014) | MLB pitchers with primary UCLR: 147 for RTP analysis + 92 for competitive analysis | ERA, IP, WHIP, pitch velocity, percentage of pitches in strike zone, pitch usage (%) | Performance statistics, such as ERA (4.23 vs 4.63, respectively), BAA (0.249 vs 0.257, respectively), WHIP (1.368 vs 1.432, respectively), percentage of pitches in strike zone (51.9% vs 49.6%, respectively), IP (94.3 vs 77.3, respectively), fastball usage (63.9% vs 59.0%, respectively), and fastball pitch velocity (91.2 mph vs 90.8 mph, respectively) declined significantly from the 3 y before to the 3 y after UCLR. However, only percentage of pitches in strike zone (51.4% vs 48.5%, respectively), IP (85.5 vs 72.7, respectively), and fastball usage (62.8% vs 60.4%, respectively) differed significantly when comparing 1y before and 1y after UCLR. These 3 variables also differed when comparing 1y before with 2 y after UCLR. None of these performance variables differed when comparing pitchers with UCLR with controls. | 20 |
| Marshall41 (2019) | MLB pitchers with primary UCLR: 45 for RTP analysis + 43 for competitive analysis | ERA, IP, WHIP, walks, strikeouts, WAR | Performance did not vary between the docking and modified Jobe techniques, as well as between the palmaris and gracilis autografts. | 19 |
| Marshall42 (2018) | 46 MLB pitchers with primary UCLR | Pitch velocity, ERA, IP, pitch usage (%), WHIP, walks, strikeouts, hits, home runs, WAR | Before UCLR, pitchers with distal tears (ERA: 3.93; WHIP: 1.32; WAR: 0.9; fastball pitch velocity: 93.0 mph) performed better than did pitchers with proximal tears (ERA: 5.11; WHIP: 1.47; WAR: 0.1; fastball pitch velocity: 90.6 mph). None of these differences were observed after UCLR, but IP was lower in the proximal tear group (58.3) versus the distal tear group (97.9). Pitchers with chronic tears had significantly higher ERA before UCLR (4.49) compared with after UCLR (3.80). | 19 |
| Peterson47 (2018) | 87 MLB pitchers with primary UCLR | No. of pitches thrown, pitch usage (%), pitching appearances | Pitching appearances (76.1 vs 62.3, respectively) and No. of pitches thrown (3026.2 vs 2219.9, respectively) decreased from the 2 seasons before UCLR to the 2 seasons after UCLR. Fastball usage also dropped every season, with fastballs accounting for 64.3% of pitches 2 y before, 62.2% 1 y before, 61.6% 1y after, and 61.3% 2 y after UCLR. All other pitch types did not differ significantly in usage. | 18 |
| Portney48 (2017) | MLB pitchers: 50 with primary UCLR + 77 controls | Pitch usage (%), pitch velocity, strikes thrown (%) | No significant differences were observed in pitch usage, pitch velocity, or ball/strike percentage between the index year, 1 y after UCLR, and 2 y after UCLR. No differences were observed between pitchers with UCLR and controls. | 20 |
| Selley51 (2019) | 292 MLB pitchers with primary UCLR (192 for competitive analysis) | Hits, walks, strikeouts, home runs, FIP, pitching WAR, ERA, IP, WHIP, pitch velocity, WPA, LI, pitch usage (%), strikes thrown (%) | Performance decreased significantly from before to after UCLR, as shown for ERA (4.37 vs 4.83, respectively), IP (90.0 vs 61.8, respectively), hits per 9 innings (9.07 vs 9.38, respectively), home runs per 9 innings (1.00 vs 1.13, respectively), FIP (4.28 vs 4.57, respectively), WAR (1.13 vs 0.55, respectively), WPA (0.29 vs –0.03, respectively), and LI (1.07 vs 0.96, respectively). Fastball usage (63.9% vs 60.3%, respectively), fastball pitch velocity (91.8 mph vs 90.9 mph, respectively), and percentage of pitches in strike zone (49.2% vs 47.4%, respectively) all decreased significantly from before to after UCLR as well. When comparing statistics before surgery with statistics from years 2 and 3 after surgery, the only significant performance differences were fastball pitch velocity (91.39 mph vs 90.80 mph, respectively) and percentage of pitches in strike zone (49.2% vs 48.0%, respectively). | 20 |
| Jones30 (2013) | 14 MLB pitchers with revision UCLR | ERA, IP, strikeouts, and walks for after revision UCLR only; percentage of prerevision UCLR workload achieved from before to after surgery | Relief pitchers achieved 50% of their previous workload, with only 2 of 11 reaching a workload higher than that before revision UCLR (103% and 117% of workload). Starting pitchers achieved 35% of their previous workload, with 0 of 7 exceeding their previous workload. | 16 |
| Keller33 (2017) | MLB pitchers: 29 with revision UCLR + 121 controls with only primary UCLR | IP, No. of pitches thrown, pitch velocity, pitch usage (%) | No differences in games pitched, IP, or No. of pitches thrown were observed between pitchers with revision UCLR and those with primary UCLR only. Fastball pitch velocity also did not differ between groups, but pitchers who required revision UCLR had higher fastball usage (69.5%) than did pitchers who did not require revision UCLR (60.7%). | 19 |
| Keller32 (2017) | MLB pitchers: 28 with revision UCLR + 137 controls with only primary UCLR | IP, No. of pitches thrown, No. of games pitched | Pitchers who later required revision UCLR pitched near or above their previous workload, while pitchers who did not require revision UCLR decreased their workload after UCLR. Pitchers with revision UCLR increased games pitched by 14.1% and reduced IP by 9.8% after surgery, while those with no revision UCLR decreased games pitched by 13.6% and decreased IP by 26.0%. | 17 |
| Liu37 (2016) | 17 MLB pitchers with revision UCLR | ERA, strikeouts, BAA, IP, WHIP, FIP, pitch usage (%), pitch velocity, No. of pitches thrown | ERA, BAA, strikeouts, WHIP, fastball usage, fastball pitch velocity, and FIP did not differ from 3 seasons before to 3 seasons after revision UCLR. IP (83.97 vs 36.95, respectively) and No. of pitches thrown (1356 vs 636, respectively) decreased from before to after revision UCLR. | 20 |
| Marshall43 (2015) | MLB pitchers: 33 with revision UCLR + 33 controls with only primary UCLR | IP, ERA, strikeouts, walks, hits, WHIP, WAR, runs above replacement, runs against per 9 innings | IP (67.18 vs 39.10, respectively), walks per 9 innings (4.02 vs 4.79, respectively), and runs against per 9 innings (4.64 vs 4.45, respectively) worsened significantly from before to after revision UCLR. When comparing the postoperative performance of pitchers with revision UCLR with that of controls, IP (36.95 vs 75.00, respectively) and walks per 9 innings (4.75 vs 3.49, respectively) differed significantly. | 21 |
| Begly2 (2018) | MLB position players: 26 with primary UCLR + 26 controls | At-bats, WAR, isolated power, OPS, batting average, plate appearances | Plate appearances (460 vs 367, respectively), at-bats (460 vs 326, respectively), and WAR based on ±2 seasons (2.3 vs 1.0, respectively) decreased significantly from before to after UCLR, while all other performance statistics did not differ significantly. No performance declines were observed when comparing players with UCLR with controls. | 20 |
| Jack27 (2018) | MLB position players: 33 with primary UCLR + 33 controls | WAR, OPS, plate appearances, batting average, OBP, SLG | No differences were observed between position players with UCLR and controls when comparing both pre- and post-UCLR performance. However, outfielder WAR decreased from 1.5 to 0.8 from before to after UCLR, but all other performance measures did not differ significantly. | 20 |
| Marshall40 (2018) | Professional catchers: 25 with primary UCLR + 25 controls | Offensive: games started, innings played, at-bats, runs, hits, home runs, runs batted in, walks, strikeouts, batting average, OBP, SLG; defensive: errors, fielding percentage, passed balls, bases stolen against, players caught stealing, caught stealing percentage | The only performance statistic that significantly differed was games played from before UCLR (62.2) compared with the first year after UCLR (44.3). Catchers with UCLR had significantly higher SLG (0.40) than did controls (0.37). No other offensive or defensive statistics varied before and after the injury or between the UCLR and control groups. | 19 |
| Camp3 (2018) | Amateur pitchers: 252 with UCLR before draft + 756 controls (50 with UCLR + 92 controls for competitive analysis) | WAR, IP, ERA, WHIP after UCLR only | No post-UCLR performance statistics differed significantly between pitchers with UCLR and their matched controls. | 15 |
| Wymore53 (2016) | Amateur pitchers: 13 with UCLR before draft + 114 controls (38 with UCLR + 29 controls for competitive analysis) | IP, ERA, WHIP, pitch velocity, games, hits, home runs, strikeouts, walks after UCLR only | Home runs allowed per inning differed significantly between pitchers with UCLR (0.07) and their matched controls (0.08). All other performance variables did not differ significantly between pitchers with UCLR and controls. | 22 |
aBAA, batting average against; ERA, earned run average; FIP, fielding independent pitching; IP, innings pitched; LI, leverage index; MiLB, Minor League Baseball; MLB, Major League Baseball; OBP, on-base percentage; OPS, on-base plus slugging; RTP, return to play; SLG, slugging percentage; STROBE, STrengthening the Reporting of OBservational studies in Epidemiology; UCLR, ulnar collateral ligament reconstruction; WAR, wins above replacement; WHIP, walks plus hits per inning pitched; WPA, win probability added.
bScore of a possible 22 points.