- Email: [email protected]
Performance and Return to Sport After Hip Arthroscopy for Femoroacetabular Impingement in Professional Athletes Differs Between Sports
Performance and Return to Sport After Hip Arthroscopy for Femoroacetabular Impingement in Professional Athletes Differs Between Sports Robert A. Jack II, M.D., Kyle R. Sochacki, M.D., Takashi Hirase, M.D., M.P.H., Justin W. Vickery, B.S., and Joshua D. Harris, M.D.
Purpose: To determine (1) return-to-sport rates for National Football League, Major League Baseball, National Basketball Association, and National Hockey League (NHL) athletes after hip arthroscopy for femoroacetabular impingement syndrome, (2) postoperative return-to-sport rate differences between sports, (3) differences in postoperative career length and games per season, (4) differences in preoperative and postoperative performance, and (5) postoperative performance compared with that of matched control players. Methods: Professional athletes who underwent hip arthroscopy for femoroacetabular impingement syndrome were identified. Matched control players were identified by position, age, experience, and performance. Return to sport was defined as playing in at least 1 game after surgery. Continuous variables for each group were compared by using a 2-tailed paired-samples Student t test or c2 test. A Bonferroni correction was used to control for multiple comparisons with statistical significance defined by a P value < .002. Results: One hundred seventy-two players (86.4%) (mean age, 28.8 5.2 years) were able to return to sport at an average of 7.1 4.1 months. Athletes played 3.5 2.4 years after surgery without significant differences between sports (P > .002). NHL players who underwent surgery played significantly fewer years (4.4 vs 3.3 years) (P < .001) and fewer games per season (4 fewer games) (P <.001) after surgery compared with control players. NHL players also had a significant decrease in performance after surgery compared with their performance before surgery (P < .001). In National Football League, Major League Baseball, and National Basketball Association athletes, no significant differences were found in games per season, career length, or preoperative performance compared with postoperative performance and performance of matched control players (P > .002). Conclusion: The RTS rate for professional athletes after surgery for femoroacetabular impingement syndrome is high. Only NHL athletes had significantly shorter careers and played significantly fewer games per season compared with matched control players, with no difference between sports. NHL athletes had significantly worse postoperative performance compared with preoperative performance, with all other sports demonstrating a career-related decline similar to that of matched control players.
See commentary on page 1429 emoroacetabular Impingement (FAI) syndrome is a common cause of hip pain characterized by abnormal joint morphology leading to aberrant contact between the proximal femur (cam) and acetabular rim (pincer).1-4 In patients experiencing symptoms, this often results in significant functional disability and
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impaired performance.3,5,6 In patients dissatisfied with their hip condition despite nonsurgical treatment, hip arthroscopy with correction of cam and/or pincer morphology and labral preservation is successful in reducing pain, improving function, and enabling return to activities, including sports.7-9
From the Houston Methodist Orthopedic and Sports Medicine, Houston, Texas, U.S.A. The authors report the following potential conflicts of interest or sources of funding: J.D.H. has the following disclosures: AAOS: Board or committee member; American Orthopedics Society for Sports Medicine: Board or committee member; Arthroscopy: Editorial or governing board; Arthroscopy Association of North America: Board or committee member; DePuy, A Johnson & Johnson Company: Research support; Frontiers In Surgery: Editorial or governing board; NIA Magellan: Paid consultant; SLACK Incorporated: Publishing royalties, financial or material support; Smith and
Nephew: Paid presenter or speaker, Paid consultant, Research support; Össur: Paid speaker. Full ICMJE author disclosure forms are available for this article online, as supplementary material. Received July 17, 2018; accepted October 27, 2018. Address correspondence to Joshua D. Harris, M.D., 6445 Main St, Suite 2500, Houston, TX 77030, U.S.A. E-mail: [email protected] Ó 2019 by the Arthroscopy Association of North America 0749-8063/18878/$36.00 https://doi.org/10.1016/j.arthro.2018.10.153
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Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 35, No 5 (May), 2019: pp 1422-1428
PERFORMANCE AND RETURN TO SPORT
Previous studies have examined the epidemiology and outcomes of corrective surgery for FAI syndrome in professional athletes.6,10,11 The return-to-sport (RTS) rate for these professional athletes from the National Football League (NFL), Major League Baseball (MLB), National Hockey League (NHL), and Major League Soccer has been reported to range from 88% to 96% at an average of 5.4 to 9.2 months after surgery with significant improvement in several patient-reported outcome measures.6,10,12-14 However, these studies are limited with no comparison between sports, and postoperative performance in NFL players was investigated in only 1 study.6 Furthermore, classifying return to sport is highly multifactorial and heterogeneous between sports, between positions within a sport, and with respect to the definition of performance before or after surgery. Given the increasing revenue and popularity of professional sports, it is important to understand surgical outcomes in this patient population. The purposes of this study were to determine the (1) RTS rate in NFL, MLB, National Basketball Association (NBA), and NHL athletes after hip arthroscopy for FAI syndrome; (2) differences in postoperative RTS rates between sports; (3) postoperative career length and games per season; (4) differences in preoperative and postoperative performance; and (5) postoperative performance compared with that of matched control players. We hypothesized that professional players who underwent hip arthroscopy for FAI syndrome would have a (1) 90% or higher RTS rate, (2) no significant differences in RTS rates between sports, (3) no significant differences in postoperative career length and games per season, (4) no significant differences in postoperative performance compared with preoperative performance, and (5) no significant differences in postoperative performance compared with performance of matched control players.
Methods Professional athletes from the NFL, NBA, MLB, and NHL who underwent hip arthroscopy for FAI syndrome between 2000 and 2016 were identified through team websites, publicly available internet-based injury reports, player profiles and biographies, and press releases. The search was manually conducted by 2 orthopedic surgery residents (R.A.J. and K.R.S.) in December 2017. Searches were performed for all professional teams. This method of data collection has been used successfully in multiple prior studies of professional athletes.15-24 All players identified were included in this study as it related to RTS rate. A player was deemed to have returned to sport if he played in any game after surgery. A player did not return to sport if he did not play in any game after surgery. Inclusion criteria were any player on an active roster before hip arthroscopy for FAI.
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Players were included if they were found to have undergone hip arthroscopy for FAI as reported by at least 2 separate sources. Information from these sources was verified against each other and through independent web-based searches of team press releases that confirmed the date of surgery for each player.15,16 If this information was unclear, unverified, or unable to be obtained, the athlete was excluded from the study. Athletes who were injured and underwent procedures before completing their first regular season were excluded because no preoperative data would be available for comparison. Players who underwent hip arthroscopy for FAI in the 2017 season were excluded from analysis because their opportunity to return to sport was less than 1 year and because postoperative statistics could not be obtained. Demographic data were collected and included each player’s age, position, date of injury, and date of surgery. Each player was classified by position played and sport. Performance data were collected from a publicly available online player database (www.pro-footballreference.com, www.baseball-reference.com, www. fangraphs.com, www.basketball-reference.com, and www.hockey-reference.com) before and after surgery. There were no players for whom performance data could not be identified. Each performance data category was divided by the number of games played to account for discrepancies in the number of games played per season. Only data from regular season games were included. Pre-season, spring training, minor league, and playoff games were excluded. Performance data used for comparison (preoperative vs postoperative, case vs control) in this study included previously published scoring systems for NFL and NHL players, walks plus hits per inning pitched for pitchers in MLB, on-base plus slugging percentage for hitters in MLB, and player efficiency rating for NBA players.25 Because of the possible benefits or detriments of aging and/or experience on player performance and number of games played, matched control players were selected to use for comparison with withthe surgically treated players. This control group of players was selected by matching the position, age (1 year), years of experience (1 year), body mass index, and performance data before the date of surgery for each surgically treated player. One control player was found for each surgically treated player. Each control player was given an index date that matched the surgically treated player’s surgery date to compare postoperative or post-index performance. For example, if a player with FAI syndrome had surgery 3 years into his career, the control player’s index date was 3 years into his career. A Kaplan-Meier survivorship curve with retirement as the endpoint was constructed. Kaplan-Meier analyses were compared by means of log-rank testing. The
Screening
Idenficaon
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R. A. JACK ET AL. Online search of publicly available data for professional athletes who underwent hip arthroscopy surgery from 2000 to 2017 (323 players)
Hip arthroscopy for femoroacetabular impingement (FAI) unable to be confirmed (81 players) Professional athletes who underwent FAI surgery (242 players)
Eligibility
No professional experience (11 players)
Inadequate me in league (< 1 year) (12 players)
Inadequate follow-up me (< 1 year) (23 players)
Included
Final analysis (196 players, 229 surgeries)
Fig 1. Preferred reporting items for systematic reviews and meta-analyses (PRISMA) flowchart illustrating application of exclusion criteria to determine the final number of professional athletes analyzed in this study.
continuous variables of each sport were compared by using a 2-tailed paired-samples Student t test for normally distributed data. c2 Analysis was used to analyze categorical data. A Bonferroni correction was used to control for multiple comparisons with statistical significance defined by a P value < .002.
Results One-hundred ninety-six players (221 surgeries) from 4 professional sports (NFL, NHL, MLB, NBA) who underwent hip arthroscopy for FAI were included in the study (Fig 1). Seventeen players underwent bilateral hip arthroscopy, and 8 players underwent revision hip arthroscopy as well. The mean age was 28.8 5.2 years, and the mean length of professional experience was 7.1 4.6 years at the time of surgery. One hundred seventy-two players who had 191 surgical procedures (86.4%, of 221 total surgical events) were able to return to sport after hip arthroscopy. There was no significant difference in RTS rates between sports (P > .002) (Table 1). The time to recover from surgery and return to a regular-season game was similar between sports (P > .002) (Table 1). One hundred thirteen (51.1%) players underwent hip arthroscopy in season (MLB: 28, NHL: 56, NFL: 16, NBA: 13). Fifteen
Table 1. Return to Sport After Femoroacetobular Impingement Surgery League NFL MLB NBA NHL Overall
No. of Procedures 63 57 24 77 221
RTS 84.1% 82.5% 87.5% 90.9% 86.4%
Months to RTS 6.7 3.8 8.3 4.1 6.7 4 .6 6.8 4.1 7.1 4.1
FAI, femoroacetabular impingement; MLB, Major League Baseball; NBA, National Basketball Association; NFL, National Football League; NHL, National Hockey League; RTS, return to sport.
(7.9%) athletes returned to their sport in the same season as their hip arthroscopy (MLB: 3, NHL: 7, NBA: 5). Athletes played 3.5 2.4 years after surgery, with no significant difference between sports (P > .05) (Table 2). NHL control players had significantly longer careers (4.4 vs 3.3 years) compared with NHL players who underwent hip arthroscopy (P < .001) (Table 2). Kaplan-Meier analysis (Fig 2) demonstrated no significant differences in survivorship (retirement) among the 4 sports (log rank, P ¼ .22). Overall, 81.0% of athletes were on active rosters 1 season after undergoing hip arthroscopy (Fig 3). Compared with control,players athletes undergoing hip arthroscopy had similar survivorship (retirement) overall (log-rank, P ¼ .01) (Fig 3). After hip arthroscopy, there was no significant difference in games played per season for NFL (1 less game), MLB (5 fewer games), or NBA (8 fewer games) athletes (P > .002) (Fig 4). NHL athletes played in significantly fewer games per season after surgery (4 fewer games) compared with matched control players (P < .001), but there was no significant difference compared with number of games played before surgery (P > .002). NHL players had a significant decrease in postoperative performance compared with preoperative performance (P < .001), but there was no significant difference compared with performance of matched control players (P >.002) (Fig 5). Goalie performance score decreased from 1.67 before surgery to 1.6 after surgery (P > .002). There was no significant difference in postoperative performance compared with preoperative performance Table 2. Career Length After Femoroacetobular Impingement Surgery League NFL MLB NBA NHL Overall
Cases 3.5 2.1 3.3 2.4 4.4 3.0 3.3 2.5 3.5 2.4
Control players 3.7 2.2 4.0 2.9 5.2 3.4 4.4 2.7 4.2 2.7
P value .44 .01 .07 <.001* <.001*
MLB, Major League Baseball; NBA, National Basketball Association; NFL, National Football League; NHL, National Hockey League. *Statistically significant difference in career length between control players and surgically treated players after hip arthroscopy.
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PERFORMANCE AND RETURN TO SPORT 100% 90% 80%
PERCENT SURVIVAL
Fig 2. Kaplan-Meier survival analysis for athletes after hip arthroscopy Zero (0) signifies year of surgery. (MLB, Major League Baseball; NBA, National Basketball Association; NFL, National Football League; NHL, National Hockey Leagues.)
70% 60% 50% 40% 30% 20% 10% 0% 0
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and performance of matched control players for MLB, NBA, and NFL players (P > .002) (Fig 5).
Discussion The study hypotheses were partially confirmed with an 86.4% RTS rate and no significant difference in RTS rates between sports. NHL athletes played in significantly fewer games per season (4 fewer games) after hip arthroscopy compared with matched control players and had significantly shorter careers after surgery compared with control players (4.4 vs 3.3 years). There were no significant differences in career length or games played per season between sports. Additionally,
MLB
NBA
NHL
NHL players had a significant decrease in performance after hip arthroscopy compared with preoperative performance. For NFL, MLB, and NBA athletes who underwent hip arthroscopy, comparison of games per season, career length, and performance before and after surgery revealed no significant differences. In addition, no significant differences were found in number of games per season, career length, or performance when the surgically treated athletes were compared with matched control players. Previous studies of professional athletes (MLB, NHL, NFL, MLS) have demonstrated RTS rates ranging from 88% to 96% at an average of 5.4 to 9.2 months after
100% 90%
PERCENT SURVIVAL
80% 70% 60%
Fig 3. Kaplan-Meier survival analysis for cases and controls after hip arthroscopy in all 4 professional sports. Zero (0) signifies year of surgery or index year.
50% 40% 30% 20% 10% 0% 0
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4% 2% 0% -2%
NFL
MLB
NBA
NHL
Overall
-4% -6% -8% -10% -12% -14% -16% Cases
Controls
Fig 4. Change in games per season after hip arthroscopy surgery. The diamond (A) indicates significant difference (P < .002) in games per season between surgically treated players and control players after index date. (Cases, surgically treated players; Controls, control players; MLB, Major League Baseball; NBA, National Basketball Association; NFL, National Football League; NHL, National Hockey Leagues.)
surgery.6,10,13,14,26 This finding is similar to the average RTS rate in the present study of 86.4% at 7.1 months. RTS rates did not differ between sports, but MLB players had more time off before returning to a game (8.3 vs 6.7 months), although this did not reach statistical significance. Degen et al.14 report a similar time to return in competitive baseball players (8.6 months). This increased RTS time could be attributable to a longer off-season in baseball compared with other sports. Only 3 MLB players were able to return to sport in the same season as their surgery, and 92.1% of MLB players were in the offseason when they were expected to return. Therefore, the RTS time is likely longer than it would have been if the players were not in the offseason. NHL athletes played in significantly fewer games per season and had significantly shorter careers compared with matched control players. This same trend was seen in professional athletes after anterior cruciate ligament reconstruction and in NFL players after hip arthroscopy.6,25 However, in a study by Mai et al.,25 NFL players had significantly shorter career lengths and played in significantly fewer games per season compared with athletes in other sports after anterior cruciate ligament reconstruction. In the present study, there were no differences in career length or games played per season between sports. The observed differences between NFL and other sports in the study by Mai et al.25 could be attributable to the higher body mass index in NFL athletes, which has been shown to place more stress on a reconstructed ligament and lead to associated intraarticular injuries at the time of anterior cruciate ligament injury.25,27 This same detrimental effect of body mass index on patient outcomes has not been demonstrated in patients after hip arthroscopy and likely contributes to the similar career length and
number of games played per season between sports in the present study.28-30 There was no significant difference in performance when matched control players were compared with surgically treated NFL, MLB, and NBA players. Although not statistically significant, postoperative performance in NFL players improved compared with preoperative performance, whereas performance of matched control players decreased. Additionally, surgically treated MLB and NBA players had postoperative performance that decreased at a rate similar to that observed in the control players. This indicates that the postoperative performance decline is likely attributable to the career-based decline that is typically seen in professional athletes rather than the hip arthroscopy. This is similar to results of a recent study of NFL players after hip arthroscopy in which no significant differences in postoperative performance were found when compared with performance of matched control players.6 NHL athletes, on the other hand, had the greatest decrease in performance and significantly worse postoperative performance compared with preoperative performance. In several studies, increased rates of FAI and overuse hip injuries have been reported in hockey players as a result of repetitive hip flexion, adduction, and external rotation during skating.31-35 A previous study evaluating performance in professional hockey players demonstrated similar results with a postoperative decrease in performance of 14 points compared with 3 points in the control group, although this did not reach statistical significance.36 The explanation for this outcome is likely associated with position played. In the present study, only goaltenders accounted for the significant differences; offensive and defensive players had no significant decrease in performance. Goaltenders must flex and internally rotate their hips during the butterfly technique while making a save.11,34 This position-specific technique places
10% 0% NFL
MLB
NBA
NHL
Overall
-10% -20% -30% -40% -50% Cases
Controls
Fig 5. Change in performance after hip arthroscopy surgery. The triangle (:) indicates significant difference (P < .002) between postoperative and preoperative performance.
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significant stress across the hips, leading to impingement and likely contributing to decreased performance. Limitations There are limitations to this study and other studies in which similar methods are used. The use of publicly available data to identify players who underwent hip arthroscopy for FAI may be prone to selection, reporting, and observer bias. However, this method of data acquisition has been used in multiple previous studies.15-24,37 By only including the highest level of professional players, these data may only apply to elitelevel athletes. Professional players have a higher rate of return to play than nonprofessional players.38 This is believed to be a result of the inherently high talent and determination present at this level with higher income potential.11 Additionally, players may retire for reasons not related to performance that cannot be accounted for in this type of study. We may not have been able to identify all previous hip surgeries for the included players, which has been shown to have an effect on the outcomes of hip arthroscopy for FAI.39,40 Also, career length and performance were not adjusted for “time missed” for players who underwent hip arthroscopy for FAI. Additionally, the comparison of RTS times between sports may be affected by the different offseason lengths. Inherent to this type of study, there are multiple unknown confounding variables such as the lack of direct physical contact with subjects, patient-reported outcomes, and access to medical records to corroborate diagnosis and treatment. The use of public data limits the ability to determine the chronicity and severity of the injury. We could not reliably determine the surgeon who performed the operation or the exact operative procedure used in each hip arthroscopy (labral debridement vs repair vs reconstruction, degree of cam/ pincer correction/undercorrection/overcorrection, chondral treatments for variable degrees of articular cartilage pathology/arthritis, or capsular closure/repair/ plication/shift; periarticular extra-articular peritrochanteric, deep gluteal space, or athletic pubalgia/ core muscle injury). Heterogeneity of surgeons or surgical experience is also a limitation. Other limitations include the absence of patient-reported outcomes and incomplete follow-up and career length for players still in their respective leagues.
Conclusion The RTS rate for professional athletes after FAI surgery is high. Only NHL athletes had significantly shorter careers and played significantly fewer games per season than matched control players. NHL athletes had significantly worse postoperative performance compared with preoperative performance, with players
of all other sports demonstrating a career-related decline similar to that of matched control players.
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28. Gupta A, Redmond JM, Hammarstedt JE, Lindner D, Stake CE, Domb BG. Does obesity affect outcomes after hip arthroscopy? A cohort analysis. J Bone Joint Surg Am 2015;97:16-23. 29. Gupta A, Redmond JM, Hammarstedt JE, Stake CE, Domb BG. Does obesity affect outcomes in hip arthroscopy? A matched-pair controlled study with minimum 2-year follow-up. Am J Sports Med 2015;43:965-971. 30. Saltzman BM, Kuhns BD, Basques B, et al. The influence of body mass index on outcomes after hip arthroscopic surgery with capsular plication for the treatment of femoroacetabular impingement. Am J Sports Med 2017;45: 2303-2311. 31. Epstein DM, McHugh M, Yorio M, Neri B. Intra-articular hip injuries in National Hockey League players: A descriptive epidemiological study. Am J Sports Med 2013;41:343-348. 32. Philippon MJ, Ho CP, Briggs KK, Stull J, LaPrade RF. Prevalence of increased alpha angles as a measure of camtype femoroacetabular impingement in youth ice hockey players. Am J Sports Med 2013;41:1357-1362. 33. Siebenrock KA, Kaschka I, Frauchiger L, Werlen S, Schwab JM. Prevalence of cam-type deformity and hip pain in elite ice hockey players before and after the end of growth. Am J Sports Med 2013;41:2308-2313. 34. Bizzini M, Notzli HP, Maffiuletti NA. Femoroacetabular impingement in professional ice hockey players: A case series of 5 athletes after open surgical decompression of the hip. Am J Sports Med 2007;35:1955-1959. 35. Stull JD, Philippon MJ, LaPrade RF. "At-risk" positioning and hip biomechanics of the Peewee ice hockey sprint start. Am J Sports Med 2011;39:29S-35S (suppl). 36. McDonald JE, Herzog MM, Philippon MJ. Performance outcomes in professional hockey players following arthroscopic treatment of FAI and microfracture of the hip. Knee Surg Sports Traumatol Arthrosc 2014;22:915-919. 37. Jack RA II, Sochacki KR, Gardner SS, et al. Performance and return to sport after Achilles tendon repair in National Football League players. Foot Ankle Int 2017;38: 1092-1099. 38. Nho SJ, Magennis EM, Singh CK, Kelly BT. Outcomes after the arthroscopic treatment of femoroacetabular impingement in a mixed group of high-level athletes. Am J Sports Med 2011;39:14S-19S (suppl). 39. Domb BG, Martin TJ, Gui C, Chandrasekaran S, SuarezAhedo C, Lodhia P. Predictors of clinical outcomes after hip arthroscopy: A prospective analysis of 1038 patients with 2-year follow-up. Am J Sports Med 2018;46: 1324-1330. 40. Sardana V, Philippon MJ, de Sa D, et al. Revision hip arthroscopy indications and outcomes: A Systematic review. Arthroscopy 2015;31:2047-2055.
Purpose: To determine (1) return-to-sport rates for National Football League, Major League Baseball, National Basketball Association, and National Hockey League (NHL) athletes after hip arthroscopy for femoroacetabular impingement syndrome, (2) postoperative return-to-sport rate differences between sports, (3) differences in postoperative career length and games per season, (4) differences in preoperative and postoperative performance, and (5) postoperative performance compared with that of matched control players. Methods: Professional athletes who underwent hip arthroscopy for femoroacetabular impingement syndrome were identified. Matched control players were identified by position, age, experience, and performance. Return to sport was defined as playing in at least 1 game after surgery. Continuous variables for each group were compared by using a 2-tailed paired-samples Student t test or c2 test. A Bonferroni correction was used to control for multiple comparisons with statistical significance defined by a P value < .002. Results: One hundred seventy-two players (86.4%) (mean age, 28.8 5.2 years) were able to return to sport at an average of 7.1 4.1 months. Athletes played 3.5 2.4 years after surgery without significant differences between sports (P > .002). NHL players who underwent surgery played significantly fewer years (4.4 vs 3.3 years) (P < .001) and fewer games per season (4 fewer games) (P <.001) after surgery compared with control players. NHL players also had a significant decrease in performance after surgery compared with their performance before surgery (P < .001). In National Football League, Major League Baseball, and National Basketball Association athletes, no significant differences were found in games per season, career length, or preoperative performance compared with postoperative performance and performance of matched control players (P > .002). Conclusion: The RTS rate for professional athletes after surgery for femoroacetabular impingement syndrome is high. Only NHL athletes had significantly shorter careers and played significantly fewer games per season compared with matched control players, with no difference between sports. NHL athletes had significantly worse postoperative performance compared with preoperative performance, with all other sports demonstrating a career-related decline similar to that of matched control players.
See commentary on page 1429 emoroacetabular Impingement (FAI) syndrome is a common cause of hip pain characterized by abnormal joint morphology leading to aberrant contact between the proximal femur (cam) and acetabular rim (pincer).1-4 In patients experiencing symptoms, this often results in significant functional disability and
F
impaired performance.3,5,6 In patients dissatisfied with their hip condition despite nonsurgical treatment, hip arthroscopy with correction of cam and/or pincer morphology and labral preservation is successful in reducing pain, improving function, and enabling return to activities, including sports.7-9
From the Houston Methodist Orthopedic and Sports Medicine, Houston, Texas, U.S.A. The authors report the following potential conflicts of interest or sources of funding: J.D.H. has the following disclosures: AAOS: Board or committee member; American Orthopedics Society for Sports Medicine: Board or committee member; Arthroscopy: Editorial or governing board; Arthroscopy Association of North America: Board or committee member; DePuy, A Johnson & Johnson Company: Research support; Frontiers In Surgery: Editorial or governing board; NIA Magellan: Paid consultant; SLACK Incorporated: Publishing royalties, financial or material support; Smith and
Nephew: Paid presenter or speaker, Paid consultant, Research support; Össur: Paid speaker. Full ICMJE author disclosure forms are available for this article online, as supplementary material. Received July 17, 2018; accepted October 27, 2018. Address correspondence to Joshua D. Harris, M.D., 6445 Main St, Suite 2500, Houston, TX 77030, U.S.A. E-mail: [email protected] Ó 2019 by the Arthroscopy Association of North America 0749-8063/18878/$36.00 https://doi.org/10.1016/j.arthro.2018.10.153
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Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 35, No 5 (May), 2019: pp 1422-1428
PERFORMANCE AND RETURN TO SPORT
Previous studies have examined the epidemiology and outcomes of corrective surgery for FAI syndrome in professional athletes.6,10,11 The return-to-sport (RTS) rate for these professional athletes from the National Football League (NFL), Major League Baseball (MLB), National Hockey League (NHL), and Major League Soccer has been reported to range from 88% to 96% at an average of 5.4 to 9.2 months after surgery with significant improvement in several patient-reported outcome measures.6,10,12-14 However, these studies are limited with no comparison between sports, and postoperative performance in NFL players was investigated in only 1 study.6 Furthermore, classifying return to sport is highly multifactorial and heterogeneous between sports, between positions within a sport, and with respect to the definition of performance before or after surgery. Given the increasing revenue and popularity of professional sports, it is important to understand surgical outcomes in this patient population. The purposes of this study were to determine the (1) RTS rate in NFL, MLB, National Basketball Association (NBA), and NHL athletes after hip arthroscopy for FAI syndrome; (2) differences in postoperative RTS rates between sports; (3) postoperative career length and games per season; (4) differences in preoperative and postoperative performance; and (5) postoperative performance compared with that of matched control players. We hypothesized that professional players who underwent hip arthroscopy for FAI syndrome would have a (1) 90% or higher RTS rate, (2) no significant differences in RTS rates between sports, (3) no significant differences in postoperative career length and games per season, (4) no significant differences in postoperative performance compared with preoperative performance, and (5) no significant differences in postoperative performance compared with performance of matched control players.
Methods Professional athletes from the NFL, NBA, MLB, and NHL who underwent hip arthroscopy for FAI syndrome between 2000 and 2016 were identified through team websites, publicly available internet-based injury reports, player profiles and biographies, and press releases. The search was manually conducted by 2 orthopedic surgery residents (R.A.J. and K.R.S.) in December 2017. Searches were performed for all professional teams. This method of data collection has been used successfully in multiple prior studies of professional athletes.15-24 All players identified were included in this study as it related to RTS rate. A player was deemed to have returned to sport if he played in any game after surgery. A player did not return to sport if he did not play in any game after surgery. Inclusion criteria were any player on an active roster before hip arthroscopy for FAI.
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Players were included if they were found to have undergone hip arthroscopy for FAI as reported by at least 2 separate sources. Information from these sources was verified against each other and through independent web-based searches of team press releases that confirmed the date of surgery for each player.15,16 If this information was unclear, unverified, or unable to be obtained, the athlete was excluded from the study. Athletes who were injured and underwent procedures before completing their first regular season were excluded because no preoperative data would be available for comparison. Players who underwent hip arthroscopy for FAI in the 2017 season were excluded from analysis because their opportunity to return to sport was less than 1 year and because postoperative statistics could not be obtained. Demographic data were collected and included each player’s age, position, date of injury, and date of surgery. Each player was classified by position played and sport. Performance data were collected from a publicly available online player database (www.pro-footballreference.com, www.baseball-reference.com, www. fangraphs.com, www.basketball-reference.com, and www.hockey-reference.com) before and after surgery. There were no players for whom performance data could not be identified. Each performance data category was divided by the number of games played to account for discrepancies in the number of games played per season. Only data from regular season games were included. Pre-season, spring training, minor league, and playoff games were excluded. Performance data used for comparison (preoperative vs postoperative, case vs control) in this study included previously published scoring systems for NFL and NHL players, walks plus hits per inning pitched for pitchers in MLB, on-base plus slugging percentage for hitters in MLB, and player efficiency rating for NBA players.25 Because of the possible benefits or detriments of aging and/or experience on player performance and number of games played, matched control players were selected to use for comparison with withthe surgically treated players. This control group of players was selected by matching the position, age (1 year), years of experience (1 year), body mass index, and performance data before the date of surgery for each surgically treated player. One control player was found for each surgically treated player. Each control player was given an index date that matched the surgically treated player’s surgery date to compare postoperative or post-index performance. For example, if a player with FAI syndrome had surgery 3 years into his career, the control player’s index date was 3 years into his career. A Kaplan-Meier survivorship curve with retirement as the endpoint was constructed. Kaplan-Meier analyses were compared by means of log-rank testing. The
Screening
Idenficaon
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R. A. JACK ET AL. Online search of publicly available data for professional athletes who underwent hip arthroscopy surgery from 2000 to 2017 (323 players)
Hip arthroscopy for femoroacetabular impingement (FAI) unable to be confirmed (81 players) Professional athletes who underwent FAI surgery (242 players)
Eligibility
No professional experience (11 players)
Inadequate me in league (< 1 year) (12 players)
Inadequate follow-up me (< 1 year) (23 players)
Included
Final analysis (196 players, 229 surgeries)
Fig 1. Preferred reporting items for systematic reviews and meta-analyses (PRISMA) flowchart illustrating application of exclusion criteria to determine the final number of professional athletes analyzed in this study.
continuous variables of each sport were compared by using a 2-tailed paired-samples Student t test for normally distributed data. c2 Analysis was used to analyze categorical data. A Bonferroni correction was used to control for multiple comparisons with statistical significance defined by a P value < .002.
Results One-hundred ninety-six players (221 surgeries) from 4 professional sports (NFL, NHL, MLB, NBA) who underwent hip arthroscopy for FAI were included in the study (Fig 1). Seventeen players underwent bilateral hip arthroscopy, and 8 players underwent revision hip arthroscopy as well. The mean age was 28.8 5.2 years, and the mean length of professional experience was 7.1 4.6 years at the time of surgery. One hundred seventy-two players who had 191 surgical procedures (86.4%, of 221 total surgical events) were able to return to sport after hip arthroscopy. There was no significant difference in RTS rates between sports (P > .002) (Table 1). The time to recover from surgery and return to a regular-season game was similar between sports (P > .002) (Table 1). One hundred thirteen (51.1%) players underwent hip arthroscopy in season (MLB: 28, NHL: 56, NFL: 16, NBA: 13). Fifteen
Table 1. Return to Sport After Femoroacetobular Impingement Surgery League NFL MLB NBA NHL Overall
No. of Procedures 63 57 24 77 221
RTS 84.1% 82.5% 87.5% 90.9% 86.4%
Months to RTS 6.7 3.8 8.3 4.1 6.7 4 .6 6.8 4.1 7.1 4.1
FAI, femoroacetabular impingement; MLB, Major League Baseball; NBA, National Basketball Association; NFL, National Football League; NHL, National Hockey League; RTS, return to sport.
(7.9%) athletes returned to their sport in the same season as their hip arthroscopy (MLB: 3, NHL: 7, NBA: 5). Athletes played 3.5 2.4 years after surgery, with no significant difference between sports (P > .05) (Table 2). NHL control players had significantly longer careers (4.4 vs 3.3 years) compared with NHL players who underwent hip arthroscopy (P < .001) (Table 2). Kaplan-Meier analysis (Fig 2) demonstrated no significant differences in survivorship (retirement) among the 4 sports (log rank, P ¼ .22). Overall, 81.0% of athletes were on active rosters 1 season after undergoing hip arthroscopy (Fig 3). Compared with control,players athletes undergoing hip arthroscopy had similar survivorship (retirement) overall (log-rank, P ¼ .01) (Fig 3). After hip arthroscopy, there was no significant difference in games played per season for NFL (1 less game), MLB (5 fewer games), or NBA (8 fewer games) athletes (P > .002) (Fig 4). NHL athletes played in significantly fewer games per season after surgery (4 fewer games) compared with matched control players (P < .001), but there was no significant difference compared with number of games played before surgery (P > .002). NHL players had a significant decrease in postoperative performance compared with preoperative performance (P < .001), but there was no significant difference compared with performance of matched control players (P >.002) (Fig 5). Goalie performance score decreased from 1.67 before surgery to 1.6 after surgery (P > .002). There was no significant difference in postoperative performance compared with preoperative performance Table 2. Career Length After Femoroacetobular Impingement Surgery League NFL MLB NBA NHL Overall
Cases 3.5 2.1 3.3 2.4 4.4 3.0 3.3 2.5 3.5 2.4
Control players 3.7 2.2 4.0 2.9 5.2 3.4 4.4 2.7 4.2 2.7
P value .44 .01 .07 <.001* <.001*
MLB, Major League Baseball; NBA, National Basketball Association; NFL, National Football League; NHL, National Hockey League. *Statistically significant difference in career length between control players and surgically treated players after hip arthroscopy.
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PERFORMANCE AND RETURN TO SPORT 100% 90% 80%
PERCENT SURVIVAL
Fig 2. Kaplan-Meier survival analysis for athletes after hip arthroscopy Zero (0) signifies year of surgery. (MLB, Major League Baseball; NBA, National Basketball Association; NFL, National Football League; NHL, National Hockey Leagues.)
70% 60% 50% 40% 30% 20% 10% 0% 0
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4
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6
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9
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YEAR NFL
and performance of matched control players for MLB, NBA, and NFL players (P > .002) (Fig 5).
Discussion The study hypotheses were partially confirmed with an 86.4% RTS rate and no significant difference in RTS rates between sports. NHL athletes played in significantly fewer games per season (4 fewer games) after hip arthroscopy compared with matched control players and had significantly shorter careers after surgery compared with control players (4.4 vs 3.3 years). There were no significant differences in career length or games played per season between sports. Additionally,
MLB
NBA
NHL
NHL players had a significant decrease in performance after hip arthroscopy compared with preoperative performance. For NFL, MLB, and NBA athletes who underwent hip arthroscopy, comparison of games per season, career length, and performance before and after surgery revealed no significant differences. In addition, no significant differences were found in number of games per season, career length, or performance when the surgically treated athletes were compared with matched control players. Previous studies of professional athletes (MLB, NHL, NFL, MLS) have demonstrated RTS rates ranging from 88% to 96% at an average of 5.4 to 9.2 months after
100% 90%
PERCENT SURVIVAL
80% 70% 60%
Fig 3. Kaplan-Meier survival analysis for cases and controls after hip arthroscopy in all 4 professional sports. Zero (0) signifies year of surgery or index year.
50% 40% 30% 20% 10% 0% 0
1
2
3
4
5
6
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YEAR Cases
Controls
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4% 2% 0% -2%
NFL
MLB
NBA
NHL
Overall
-4% -6% -8% -10% -12% -14% -16% Cases
Controls
Fig 4. Change in games per season after hip arthroscopy surgery. The diamond (A) indicates significant difference (P < .002) in games per season between surgically treated players and control players after index date. (Cases, surgically treated players; Controls, control players; MLB, Major League Baseball; NBA, National Basketball Association; NFL, National Football League; NHL, National Hockey Leagues.)
surgery.6,10,13,14,26 This finding is similar to the average RTS rate in the present study of 86.4% at 7.1 months. RTS rates did not differ between sports, but MLB players had more time off before returning to a game (8.3 vs 6.7 months), although this did not reach statistical significance. Degen et al.14 report a similar time to return in competitive baseball players (8.6 months). This increased RTS time could be attributable to a longer off-season in baseball compared with other sports. Only 3 MLB players were able to return to sport in the same season as their surgery, and 92.1% of MLB players were in the offseason when they were expected to return. Therefore, the RTS time is likely longer than it would have been if the players were not in the offseason. NHL athletes played in significantly fewer games per season and had significantly shorter careers compared with matched control players. This same trend was seen in professional athletes after anterior cruciate ligament reconstruction and in NFL players after hip arthroscopy.6,25 However, in a study by Mai et al.,25 NFL players had significantly shorter career lengths and played in significantly fewer games per season compared with athletes in other sports after anterior cruciate ligament reconstruction. In the present study, there were no differences in career length or games played per season between sports. The observed differences between NFL and other sports in the study by Mai et al.25 could be attributable to the higher body mass index in NFL athletes, which has been shown to place more stress on a reconstructed ligament and lead to associated intraarticular injuries at the time of anterior cruciate ligament injury.25,27 This same detrimental effect of body mass index on patient outcomes has not been demonstrated in patients after hip arthroscopy and likely contributes to the similar career length and
number of games played per season between sports in the present study.28-30 There was no significant difference in performance when matched control players were compared with surgically treated NFL, MLB, and NBA players. Although not statistically significant, postoperative performance in NFL players improved compared with preoperative performance, whereas performance of matched control players decreased. Additionally, surgically treated MLB and NBA players had postoperative performance that decreased at a rate similar to that observed in the control players. This indicates that the postoperative performance decline is likely attributable to the career-based decline that is typically seen in professional athletes rather than the hip arthroscopy. This is similar to results of a recent study of NFL players after hip arthroscopy in which no significant differences in postoperative performance were found when compared with performance of matched control players.6 NHL athletes, on the other hand, had the greatest decrease in performance and significantly worse postoperative performance compared with preoperative performance. In several studies, increased rates of FAI and overuse hip injuries have been reported in hockey players as a result of repetitive hip flexion, adduction, and external rotation during skating.31-35 A previous study evaluating performance in professional hockey players demonstrated similar results with a postoperative decrease in performance of 14 points compared with 3 points in the control group, although this did not reach statistical significance.36 The explanation for this outcome is likely associated with position played. In the present study, only goaltenders accounted for the significant differences; offensive and defensive players had no significant decrease in performance. Goaltenders must flex and internally rotate their hips during the butterfly technique while making a save.11,34 This position-specific technique places
10% 0% NFL
MLB
NBA
NHL
Overall
-10% -20% -30% -40% -50% Cases
Controls
Fig 5. Change in performance after hip arthroscopy surgery. The triangle (:) indicates significant difference (P < .002) between postoperative and preoperative performance.
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significant stress across the hips, leading to impingement and likely contributing to decreased performance. Limitations There are limitations to this study and other studies in which similar methods are used. The use of publicly available data to identify players who underwent hip arthroscopy for FAI may be prone to selection, reporting, and observer bias. However, this method of data acquisition has been used in multiple previous studies.15-24,37 By only including the highest level of professional players, these data may only apply to elitelevel athletes. Professional players have a higher rate of return to play than nonprofessional players.38 This is believed to be a result of the inherently high talent and determination present at this level with higher income potential.11 Additionally, players may retire for reasons not related to performance that cannot be accounted for in this type of study. We may not have been able to identify all previous hip surgeries for the included players, which has been shown to have an effect on the outcomes of hip arthroscopy for FAI.39,40 Also, career length and performance were not adjusted for “time missed” for players who underwent hip arthroscopy for FAI. Additionally, the comparison of RTS times between sports may be affected by the different offseason lengths. Inherent to this type of study, there are multiple unknown confounding variables such as the lack of direct physical contact with subjects, patient-reported outcomes, and access to medical records to corroborate diagnosis and treatment. The use of public data limits the ability to determine the chronicity and severity of the injury. We could not reliably determine the surgeon who performed the operation or the exact operative procedure used in each hip arthroscopy (labral debridement vs repair vs reconstruction, degree of cam/ pincer correction/undercorrection/overcorrection, chondral treatments for variable degrees of articular cartilage pathology/arthritis, or capsular closure/repair/ plication/shift; periarticular extra-articular peritrochanteric, deep gluteal space, or athletic pubalgia/ core muscle injury). Heterogeneity of surgeons or surgical experience is also a limitation. Other limitations include the absence of patient-reported outcomes and incomplete follow-up and career length for players still in their respective leagues.
Conclusion The RTS rate for professional athletes after FAI surgery is high. Only NHL athletes had significantly shorter careers and played significantly fewer games per season than matched control players. NHL athletes had significantly worse postoperative performance compared with preoperative performance, with players
of all other sports demonstrating a career-related decline similar to that of matched control players.
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