Athletes undergo anterior cruciate ligament reconstruction (ACLR) and subsequent rehabilitation with the goal of returning to full function afterward. While excellent outcomes have been previously reported after ACLR inprofessional athletes of individual sports, it is unknown how these differ across sports. Furthermore, because of the high level of performance that is required to return to play in a professional setting, athletes may not return to preinjury performance levels until years after surgical treatment. Previous studies in this arena have not attempted to detect these differences and quantify performance changes across short- and medium-term time points. Such information may be useful to identify sport-specific differences that may help manage patient expectations and modify rehabilitation protocols. Furthermore, variations in ACL injury rates could besecondary to differences in the mechanism of injury imposed by each sport.
This study performed a detailed outcomes analysis of professional athletes who underwent ACLR for an acuterupture across 4 major North American professional sports: National Football League (NFL), National Basketball Association (NBA), National Hockey League (NHL), and Major League Baseball (MLB). The authors aimed to identify differences in performance-based outcomes depending on the sport played.
Professional athletes who underwent ACLR were identified through a review of archives of public records. Players with concomitant knee injuries requiring repair were excluded. Athletes with conflicting medical information from different sources, revision ACLR procedures, unclear pathologies, or unclear procedures were also excluded from the study.
Demographic variables including age, BMI, position both before and after surgery, playing experience, date of the injury, date of surgery, date of the first game played after surgery, and retirement date were collected for each player. Regular-season statistics for each athlete were compiled both before and after ACLR. Statistical performance was calculated differently for each athlete depending on the sport played and using standardized,previously published scoring systems. To standardize relative performance across the 4 sports after treatment, the percentage change in performance compared with preoperative values was used.
A total of 344 professional athletes (350 knees) from 4 professional sports (NFL, n = 205; NHL, n = 48; MLB, n = 21; and NBA, n = 76) who underwent ACLR between 1984 and 2013 were identified. Demographic differences between cohorts included a significantly higher BMI in NFL players (P < 0.001) and older age andmore experience before the injury in MLB athletes (P<0.001 and P<0.001, respectively).
A total of 298 athletes (86.6%) successfully returned after index ACLR. NHL athletes had a significantly higher RTP rate compared with those of all the other sports (95.8% vs 83.4%, respectively; P = 0.04). The time to recover from surgery and return to a regular-season game was significantly shorter in the NHL athletes (258 days) and longer in the NBA players (424 days) (P < 0.001 and P = 0.002, respectively).
Athletes went on to play a mean 3.2 ± 2.9 years after surgery, with NFL athletes having significantly shorter careers (2.1 ± 2.1 years; P < 0.001). NBA and NHL athletes had significantly longer careers after ACLR (4.5 ± 3.3 years, P < 0.001 and 4.5 ± 3.1 years, P = 0.001, respectively).
Overall, 67% of athletes were still on active rosters 2 and 3 seasons after ACLR. NFL players experienced a significant decrease on active rosters 2 and 3 seasons postoperatively compared with athletes of all the other sports (P < 0.001). However, 98% of NHL players were still on active rosters 2 and 3 seasons postoperatively (P = 0.006).
After ACLR, athletes of all sports played significantly fewer games during postoperative season 1 (P < .001 toP = .008). MLB and NFL athletes did return to preinjury levels of game participation by postoperative seasons2 and 3 (P = 0.11 and P = 0.16, respectively). NBA and NHL athletes continued to participate in significantlyfewer games at postoperative seasons 2 and 3 (P < 0.001 and P < 0.001, respectively). Both NBA and NFL athletes had a significant decrease in performance for the season after surgery. NBA athletes recovered to preinjury levels of performance in seasons 2 and 3, while NFL players continued to experience a significantdecrease in performance. MLB and NHL athletes experienced no significant change in performance in both the short- (postoperative season 1) and medium-term periods (postoperative seasons 2 and 3) after surgery.
The findings suggest that NFL athletes have the worst prognosis after ACLR, with the lowest survival rate, shortest career length after surgery, and sustained decreases in performance. Conversely, NHL athletes have the best prognosis after ACLR, with the highest rates of RTP, highest survival rates, longest career length after surgery, and no significant changes in performance. The unique physical demand that each sport requires is likely one of the explanations for these differences in outcomes.
Mai HT et al. (2017) Performance-Based Outcomes After Anterior Cruciate Ligament Reconstruction in Professional Athletes Differ Between Sports. The American Journal of Sports Medicine 45, 2226-2232.
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