Hip Arthroscopy in High-Level Baseball Players J.W. Thomas Byrd, M.D., and Kay S. Jones, M.S.N., R.N.
Purpose: To report the results of hip arthroscopy among high-level baseball players as recorded by outcome scores and return to baseball. Methods: All patients undergoing hip arthroscopy were prospectively assessed with the modified Harris Hip Score. On review of all procedures performed over a 12-year period, 44 hips were identified among 41 intercollegiate or professional baseball players who had achieved 2-year follow-up. Results: Among the 41 players, follow-up averaged 45 months (range, 24 to 120 months), with a mean age of 23 years (range, 18 to 34 years). There were 23 collegiate (1 bilateral) and 18 professional (2 bilateral) baseball players, including 10 Major League Baseball players. Of the 8 Major League Baseball pitchers, 6 (75%) also underwent ulnar collateral ligament elbow surgery. Improvement in the modified Harris Hip Score averaged 13 points (from 81 points preoperatively to 94 points postoperatively); a pairedsamples t test determined that this mean improvement of 13 points was statistically significant (P < .001). Players returned to baseball after 42 of 44 procedures (95%) at a mean of 4.3 months (range, 3 to 8 months), with 90% regaining the ability to participate at their previous level of competition. There were no complications. Three players (1 bilateral) underwent repeat arthroscopy. Conclusions: This study supports the idea that arthroscopic treatment for a variety of hip pathologies in high-level baseball players provides a successful return to sport and improvement in functional outcome scores. Level of Evidence: Level IV, therapeutic case series.
H
ip disorders are increasingly recognized as a source of disability and dysfunction among athletes.1 Femoroacetabular impingement has a particular proclivity for creating joint damage among young adult athletes.2 Compensatory disorders accompanying hip pathology are also increasingly recognized as a source of disability.3 Acceleration during the pitching motion is preceded by a stride toward home plate.4 Initial velocity, developed in the lower extremities, is then transformed through the hips into rotational velocity of the trunk and is ultimately delivered to the upper extremity, culminating in ball speed. Similarly, during batting, velocity is initiated from the step of the lower extremities, transformed through the hips to trunk rotation, culminating in bat speed through the upper
From Nashville Sports Medicine Foundation, Nashville, Tennessee, U.S.A. The authors report the following potential conflict of interest or source of funding: During the study period, Nashville Sports Medicine Foundation received research support (a restricted grant) from Smith & Nephew Endoscopy. J.W.T.B. receives support from Smith & Nephew and A3 Surgical. K.S.J. receives support from Smith & Nephew. Received June 24, 2014; accepted March 5, 2015. Address correspondence to J.W. Thomas Byrd, M.D., Nashville Sports Medicine Foundation, 2011 Church St, Ste 100, Nashville, TN 37203, U.S.A. E-mail: [email protected] Ó 2015 by the Arthroscopy Association of North America 0749-8063/14529/$36.00 http://dx.doi.org/10.1016/j.arthro.2015.03.002
extremities.5 In baseball the hip is part of the complex kinematic linkage for both pitching and batting.5-11 The purpose of this study was to report the results of hip arthroscopy among high-level baseball players as recorded by outcome scores and return to baseball. We hypothesized that hip disorders may be problematic in high-level baseball players, and some may potentially benefit from arthroscopic intervention as reflected by improved outcome scores.
Methods Since 1993, all patients undergoing hip arthroscopy at our institution by a single surgeon (J.W.T.B.) have been prospectively assessed using the modified Harris Hip Score preoperatively and then postoperatively at 3, 12, 24, 60, and 120 months.12 From this prospectively gathered database, we selected all athletes who competed in baseball at the intercollegiate or professional levels and had achieved a minimum of 2 years’ follow-up. All such athletes were included, and there were no exclusion criteria. This group of baseball players represents the substance of this report. The data obtained and presented in this article have been granted exemption status by the institutional review board. The indications for arthroscopy were clinical findings of joint pathology amenable to arthroscopic intervention that had failed conservative treatment, which variously included training modifications, rehabilitation, oral
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 31, No 8 (August), 2015: pp 1507-1510
1507
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J. W. T. BYRD AND K. S. JONES
anti-inflammatory medications, and judicious use of intra-articular injections. All procedures were performed using a standard supine method that has been previously reported.13,14 Capsular closure was not performed. Rehabilitation Protocol Postoperative rehabilitation, begun on the day after surgery, was dictated by the pathology encountered and procedure performed.15 In patients who underwent simple debridement, weight bearing was allowed as tolerated with crutches for 1 week. Patients who underwent femoroplasty were allowed to bear weight as tolerated with crutches for 4 weeks to regain protective muscle tone and strength. Labral repair and refixation patients maintained 50% weight bearing for 4 weeks, limiting external rotation and maximal flexion, whereas microfracture patients were kept at a strict protected weight-bearing status for 8 weeks. Structured rehabilitation, focusing on recovery from surgery, was typically maintained for 12 weeks, followed by a functional progression directed at return to sports.
Results Follow-up averaged 45 months (range, 24 to 120 months). This study consisted of 44 hips in 41 athletes (3 bilateral). Follow-up was obtained on all athletes, although the 120-month follow-up score was missing in 1 patient. The mean age was 23 years (range, 18 to 34 years). There were 23 collegiate (1 bilateral) and 18 professional (2 bilateral) baseball players, including 10 who competed at the major league level. There were 19 pitchers, 6 catchers, 8 outfielders, and 8 infielders (6 third basemen). Among the pitchers, the push leg was involved in 12, the stride leg in 6, and both in 1. Among the 8 major league pitchers, 6 (75%) also underwent ulnar collateral ligament (UCL) surgery of the elbow. Three of these did so before hip surgery and 3 after. Among the 22 position players (non-pitchers), for batting, the front leg was involved in 8, the back leg in 12, and both in 2. The duration of symptoms before arthroscopy averaged 15 months (range, 1 to 48 months). The mean improvement in the modified Harris Hip Score was 13 points at final follow-up (from 81 points preoperatively to 94 points postoperatively); this was statistically significant (P < .001). Outcome scores at various time points are shown in Figure 1. Among the players, baseball activities were successfully resumed after 42 of the 44 procedures (95%) at a mean of 4.3 months (range, 3 to 8 months), and 90% were able to resume their previous level of competition. There were numerous diagnoses (Table 1) and various procedures performed (Table 2). There were no complications. Repeat arthroscopy was performed in 3 players, including 1 who underwent bilateral surgery, at a mean
Fig 1. Results over time. (mHHS, modified Harris Hip Score.)
of 14 months (range, 5 to 24 months) for residual or recurrent pain.
Discussion Hip disorders can be a significant source of disability among high-level baseball players. Athletes with these disorders can benefit from arthroscopic intervention, as reflected by improved outcome scores and the high likelihood of returning to baseball. The 75% incidence of UCL surgery among major league pitchers undergoing arthroscopic surgery of the hip is more than 7-fold greater than the estimated prevalence of UCL surgery among all major league pitchers and reflects how important the hip may be in the complete kinematic linkage of the pitching motion.16 Three of the pitchers underwent UCL surgery before the hip problem was addressed, whereas 3 underwent UCL surgery subsequently. An optimistic interpretation of the need for UCL surgery after hip arthroscopy would be that improved mechanics of the hip allowed more force to be delivered to the upper extremity, thus contributing to UCL failure. Alternatively, it could be argued that a pitcher plagued by residual subclinical hip dysfunction might simply continue to expose the UCL to excessive forces through poor compensatory mechanics. Either scenario is speculative, and thus no causal relation is established. Nonetheless, this high incidence of associated UCL surgery reflects that the hip is an essential element in the complex kinematic linkage of baseball mechanics. Because pitching occurs off an elevated mound, the pitching motion has been described as a controlled fall, culminating in sudden deceleration when the stride leg strikes the ground.9 We speculated that pitchers with stride-leg problems might tend to encounter trouble more quickly and have more problems with ball control because of pain, whereas push-leg problems might be better compensated for, showing a gradual decline in
HIP ARTHROSCOPY IN BASEBALL PLAYERS Table 1. Diagnoses Labral tears Acetabular chondral lesions
Cam FAI Combined FAI Ruptured ligamentum teres Loose bodies Posterior acetabular fracture Femoral chondral lesions Pincer FAI Snapping iliopsoas tendon
n 32 26 (Outerbridge grade IV in 12, grade III in 17, grade II in 1, and grade I in 6) 16 12 8 7 2 1 (grade I) 1 1
FAI, femoroacetabular impingement.
velocity, durability, and performance. However, our evaluation of the available data has not shown any findings to support this hypothesis. The duration of symptoms in pitchers with stride-leg problems (29 months) was actually longer than that in pitchers with involvement of the push leg (15 months). Moreover, there was no correlation with pitchers who required inseason surgery versus those who were able to electively undergo off-season procedures. For batters, intuitively, we might have anticipated more problems with the front leg, which is forced into internal rotation during the swing, but our data did not support this. Studies have shown that higher-caliber hitters have a larger angular velocity of the hip, but they looked at the entire hip segment and did not isolate the front leg from the back leg.7 Among the 22 position players, there was a disproportionate number of catchers (n ¼ 6), as might be expected given the extremes of repetitive flexion necessitated by the catcher’s position. Interestingly, there was also a high prevalence of third basemen (n ¼ 6). We have no explanation for this other than, perhaps, sample error associated with a relatively small number of position players (n ¼ 22). The players undergoing repeat arthroscopy represented a heterogeneous subgroup consistent with the varied nature of the disorders for which the overall group of baseball players was treated. One professional player underwent repeat arthroscopy 5 months after Table 2. Procedures Performed Labral debridement Femoroplasty Chondroplasty Acetabuloplasty Labral refixation Loose body removal Iliopsoas release Labral repair
n 30 28 27 (including 10 microfractures) 13 9 7 1 1
1509
labral repair because of residual symptoms that kept him from playing. At arthroscopy, the repair site was fully healed, with only some capsulolabral adhesions encountered. A collegiate player underwent a second arthroscopic procedure for recurrent symptoms 1 year after correction of pincer and cam impingement with labral refixation and microfracture for grade IV articular damage to the acetabulum. The second-look procedure showed significant partial failure of the previous microfracture site. A professional pitcher underwent arthroscopy of both hips 3 years apart. One side included femoroplasty for cam impingement with debridement and microfracture for a grade IV acetabular lesion. The other side included femoroplasty and acetabuloplasty with labral refixation. He underwent repeat arthroscopy of each side 1 year after the index procedures, with scarring and mild progression of chondromalacia. The insight offered from this work is meaningful because of the paucity of literature on the subject. Only one other study has been published reporting on hip disorders in overhead athletes. Klingenstein et al.17 reported on a mixed group of 34 high school, college, and professional lacrosse and baseball players. Their postoperative results showed a modified Harris Hip Score of 92 points on average, which was slightly lower than that in our study. However, their improvement of 22 points was greater because of a lower preoperative baseline score of 70 points. An explanation for these differences could be that their group was functioning at a lower level than the collegiate and professional athletes reported in our study, combined with the ceiling effect of the modified Harris Hip Score. Regardless, their observations are comparable with those of this study, with a significant improvement in outcome scores and successful return to sport. The mean improvement among the high-level baseball players in our study (13 points) is less than what we have previously published among athletes and nonathletes (range, 20.5 to 45 points).1,12,18,19 However, the overall improvement (94 points) is comparable with these previous studies (range, 81 to 96 points). The differences in the amount of improvement were a result of the much lower preoperative baseline scores in these previous studies (range, 51 to 72 points) compared with those in the baseball players in this study (81 points), reflecting the higher level of function in the baseball group. Limitations This study has 3 significant limitations. First, although it is a strength that all procedures were performed by a single surgeon and the study includes all-comers, the group of baseball players is very heterogeneous. The study spans 3 decades, during which the understanding of hip pathology and pathomechanics evolved,
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especially in reference to femoroacetabular impingement; moreover, technology has progressed, especially in the realm of labral preservation. Thus this report shows generalities, commenting only on observations regarding the role of hip disorders and disability from baseball and the role of arthroscopic intervention in addressing this disability. It does not attempt to offer specific treatment strategies that would be based on the most current methods. Second, the modified Harris Hip Score, although a validated outcome instrument, shows a significant ceiling effect, limiting its usefulness in reflecting athletic performance.20 This score is clinically relevant, correlating with patient satisfaction, although it can be overestimated with high scores.21 Newer tools, such as the International Hip Outcome Tool (iHOT), will more precisely reflect these parameters in the future.22 Lastly, this study reports on the return to baseball but not durability, that is, how long athletes continued to play. However, there are numerous variables that influence this information, including completion of collegiate careers, retirement, athletic ability, and other injuries.
Conclusions This study supports the idea that arthroscopic treatment for a variety of hip pathologies in high-level baseball players provides a successful return to sport and improvement in functional outcome scores.
References 1. Byrd JWT, Jones KS. Arthroscopic management of femoroacetabular impingement (FAI) in athletes. Am J Sports Med 2011;39:7S-13S. 2. Byrd JWT, Jones KS. Arthroscopic “femoroplasty” in the management of cam-type femoroacetabular impingement. Clin Orthop Relat Res 2009;467:739-746. 3. Bedi A, Dolan M, Leunig M, Kelly BT. Static and dynamic mechanical causes of hip pain. Arthroscopy 2011;27: 235-251. 4. Pappas AM, Zawack RM, Sullivan TJ. Biomechanics of baseball pitching. Am J Sports Med 1986;13:216-222. 5. Welch CM, Banks SA, Cook FF, Draovitch P. Hitting a baseball: A biomechanical description. J Orthop Sports Phys Ther 1995;22:193-201. 6. Guido JA Jr, Werner SL. Lower-extremity ground reaction forces in collegiate baseball pitchers. J Strength Cond Res 2012;26:1782-1785.
7. Inkster B, Murphy A, Bower R, Watsford M. Differences in the kinematics of the baseball swing between hitters of varying skill. Med Sci Sports Exerc 2011;42:1050-1054. 8. MacWilliams BA, Choi T, Perezous MK, et al. Characteristic ground reaction forces in baseball pitching. Am J Sports Med 1998;26:66-71. 9. Robb AJ, Fleisig G, Wilk K, et al. Passive ranges of motion of the hips and their relationship with pitching biomechanics and ball velocity in professional baseball pitchers. Am J Sports Med 2010;38:2487-2493. 10. Stodden DF, Langendorfer SJ, Fleisig GS, Andrews JR. Kinematic constraints associated with the acquisition of overarm throwing part I: Step and trunk actions. Res Q Exerc Sport 2006;77:417-427. 11. Wight J, Richards J, Hall S. Influence of pelvic rotation styles on baseball pitching mechanics. Sports Biomech 2004;3:67-83. 12. Byrd JWT, Jones KS. Prospective analysis of hip arthroscopy with 10-year follow-up. Clin Orthop Relat Res 2010;468:741-746. 13. Byrd JWT. Hip arthroscopy utilizing the supine position. Arthroscopy 1994;10:275-280. 14. Byrd JWT. Routine arthroscopy and access: Central and peripheral compartments, iliopsoas bursa, peritrochanteric, and subgluteal spaces. In: Byrd JWT, ed. Operative hip arthroscopy. Ed 3. New York: Springer, 2013;131-160. 15. Coplen EM, Voight ML. Rehabilitation of the hip. In: Byrd JWT, ed. Operative hip arthroscopy. Ed 3. New York: Springer, 2013;411-440. 16. Erickson BJ, Gupta AK, Harris JD, et al. Rate of return to pitching and performance after Tommy John surgery in Major League Baseball pitchers. Am J Sports Med 2014;42: 536-543. 17. Klingenstein GG, Martin RR, Kivlan B, Kelly BT. Hip injuries in the overhead athlete. Clin Orthop Relat Res 2012;470:1579-1585. 18. Byrd JW, Jones KS. Arthroscopic management of femoroacetabular impingement: Minimum 2-year follow-up. Arthroscopy 2011;27:1379-1388. 19. Byrd JW, Jones KS. Hip arthroscopy in athletes: 10-year follow-up. Am J Sports Med 2009;37:2140-2143. 20. Wright JG, Young NL. A comparison of different indices of responsiveness. J Clin Epidemiol 1997;50:239-246. 21. Aprato A, Jayasekera N, Villar RN. Does the modified Harris Hip Score reflect patient satisfaction after hip arthroscopy? Am J Sports Med 2012;40:2557-2560. 22. Mohtadi NGH, Griffin DR, Pedersen EM, et al. The development and validation of a self-administered quality-of-life outcome measure for young, active patients with symptomatic hip disease: the International Hip Outcome Tool (iHOT-33). Arthroscopy 2012;28:595-610.
Purpose: To report the results of hip arthroscopy among high-level baseball players as recorded by outcome scores and return to baseball. Methods: All patients undergoing hip arthroscopy were prospectively assessed with the modified Harris Hip Score. On review of all procedures performed over a 12-year period, 44 hips were identified among 41 intercollegiate or professional baseball players who had achieved 2-year follow-up. Results: Among the 41 players, follow-up averaged 45 months (range, 24 to 120 months), with a mean age of 23 years (range, 18 to 34 years). There were 23 collegiate (1 bilateral) and 18 professional (2 bilateral) baseball players, including 10 Major League Baseball players. Of the 8 Major League Baseball pitchers, 6 (75%) also underwent ulnar collateral ligament elbow surgery. Improvement in the modified Harris Hip Score averaged 13 points (from 81 points preoperatively to 94 points postoperatively); a pairedsamples t test determined that this mean improvement of 13 points was statistically significant (P < .001). Players returned to baseball after 42 of 44 procedures (95%) at a mean of 4.3 months (range, 3 to 8 months), with 90% regaining the ability to participate at their previous level of competition. There were no complications. Three players (1 bilateral) underwent repeat arthroscopy. Conclusions: This study supports the idea that arthroscopic treatment for a variety of hip pathologies in high-level baseball players provides a successful return to sport and improvement in functional outcome scores. Level of Evidence: Level IV, therapeutic case series.
H
ip disorders are increasingly recognized as a source of disability and dysfunction among athletes.1 Femoroacetabular impingement has a particular proclivity for creating joint damage among young adult athletes.2 Compensatory disorders accompanying hip pathology are also increasingly recognized as a source of disability.3 Acceleration during the pitching motion is preceded by a stride toward home plate.4 Initial velocity, developed in the lower extremities, is then transformed through the hips into rotational velocity of the trunk and is ultimately delivered to the upper extremity, culminating in ball speed. Similarly, during batting, velocity is initiated from the step of the lower extremities, transformed through the hips to trunk rotation, culminating in bat speed through the upper
From Nashville Sports Medicine Foundation, Nashville, Tennessee, U.S.A. The authors report the following potential conflict of interest or source of funding: During the study period, Nashville Sports Medicine Foundation received research support (a restricted grant) from Smith & Nephew Endoscopy. J.W.T.B. receives support from Smith & Nephew and A3 Surgical. K.S.J. receives support from Smith & Nephew. Received June 24, 2014; accepted March 5, 2015. Address correspondence to J.W. Thomas Byrd, M.D., Nashville Sports Medicine Foundation, 2011 Church St, Ste 100, Nashville, TN 37203, U.S.A. E-mail: [email protected] Ó 2015 by the Arthroscopy Association of North America 0749-8063/14529/$36.00 http://dx.doi.org/10.1016/j.arthro.2015.03.002
extremities.5 In baseball the hip is part of the complex kinematic linkage for both pitching and batting.5-11 The purpose of this study was to report the results of hip arthroscopy among high-level baseball players as recorded by outcome scores and return to baseball. We hypothesized that hip disorders may be problematic in high-level baseball players, and some may potentially benefit from arthroscopic intervention as reflected by improved outcome scores.
Methods Since 1993, all patients undergoing hip arthroscopy at our institution by a single surgeon (J.W.T.B.) have been prospectively assessed using the modified Harris Hip Score preoperatively and then postoperatively at 3, 12, 24, 60, and 120 months.12 From this prospectively gathered database, we selected all athletes who competed in baseball at the intercollegiate or professional levels and had achieved a minimum of 2 years’ follow-up. All such athletes were included, and there were no exclusion criteria. This group of baseball players represents the substance of this report. The data obtained and presented in this article have been granted exemption status by the institutional review board. The indications for arthroscopy were clinical findings of joint pathology amenable to arthroscopic intervention that had failed conservative treatment, which variously included training modifications, rehabilitation, oral
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 31, No 8 (August), 2015: pp 1507-1510
1507
1508
J. W. T. BYRD AND K. S. JONES
anti-inflammatory medications, and judicious use of intra-articular injections. All procedures were performed using a standard supine method that has been previously reported.13,14 Capsular closure was not performed. Rehabilitation Protocol Postoperative rehabilitation, begun on the day after surgery, was dictated by the pathology encountered and procedure performed.15 In patients who underwent simple debridement, weight bearing was allowed as tolerated with crutches for 1 week. Patients who underwent femoroplasty were allowed to bear weight as tolerated with crutches for 4 weeks to regain protective muscle tone and strength. Labral repair and refixation patients maintained 50% weight bearing for 4 weeks, limiting external rotation and maximal flexion, whereas microfracture patients were kept at a strict protected weight-bearing status for 8 weeks. Structured rehabilitation, focusing on recovery from surgery, was typically maintained for 12 weeks, followed by a functional progression directed at return to sports.
Results Follow-up averaged 45 months (range, 24 to 120 months). This study consisted of 44 hips in 41 athletes (3 bilateral). Follow-up was obtained on all athletes, although the 120-month follow-up score was missing in 1 patient. The mean age was 23 years (range, 18 to 34 years). There were 23 collegiate (1 bilateral) and 18 professional (2 bilateral) baseball players, including 10 who competed at the major league level. There were 19 pitchers, 6 catchers, 8 outfielders, and 8 infielders (6 third basemen). Among the pitchers, the push leg was involved in 12, the stride leg in 6, and both in 1. Among the 8 major league pitchers, 6 (75%) also underwent ulnar collateral ligament (UCL) surgery of the elbow. Three of these did so before hip surgery and 3 after. Among the 22 position players (non-pitchers), for batting, the front leg was involved in 8, the back leg in 12, and both in 2. The duration of symptoms before arthroscopy averaged 15 months (range, 1 to 48 months). The mean improvement in the modified Harris Hip Score was 13 points at final follow-up (from 81 points preoperatively to 94 points postoperatively); this was statistically significant (P < .001). Outcome scores at various time points are shown in Figure 1. Among the players, baseball activities were successfully resumed after 42 of the 44 procedures (95%) at a mean of 4.3 months (range, 3 to 8 months), and 90% were able to resume their previous level of competition. There were numerous diagnoses (Table 1) and various procedures performed (Table 2). There were no complications. Repeat arthroscopy was performed in 3 players, including 1 who underwent bilateral surgery, at a mean
Fig 1. Results over time. (mHHS, modified Harris Hip Score.)
of 14 months (range, 5 to 24 months) for residual or recurrent pain.
Discussion Hip disorders can be a significant source of disability among high-level baseball players. Athletes with these disorders can benefit from arthroscopic intervention, as reflected by improved outcome scores and the high likelihood of returning to baseball. The 75% incidence of UCL surgery among major league pitchers undergoing arthroscopic surgery of the hip is more than 7-fold greater than the estimated prevalence of UCL surgery among all major league pitchers and reflects how important the hip may be in the complete kinematic linkage of the pitching motion.16 Three of the pitchers underwent UCL surgery before the hip problem was addressed, whereas 3 underwent UCL surgery subsequently. An optimistic interpretation of the need for UCL surgery after hip arthroscopy would be that improved mechanics of the hip allowed more force to be delivered to the upper extremity, thus contributing to UCL failure. Alternatively, it could be argued that a pitcher plagued by residual subclinical hip dysfunction might simply continue to expose the UCL to excessive forces through poor compensatory mechanics. Either scenario is speculative, and thus no causal relation is established. Nonetheless, this high incidence of associated UCL surgery reflects that the hip is an essential element in the complex kinematic linkage of baseball mechanics. Because pitching occurs off an elevated mound, the pitching motion has been described as a controlled fall, culminating in sudden deceleration when the stride leg strikes the ground.9 We speculated that pitchers with stride-leg problems might tend to encounter trouble more quickly and have more problems with ball control because of pain, whereas push-leg problems might be better compensated for, showing a gradual decline in
HIP ARTHROSCOPY IN BASEBALL PLAYERS Table 1. Diagnoses Labral tears Acetabular chondral lesions
Cam FAI Combined FAI Ruptured ligamentum teres Loose bodies Posterior acetabular fracture Femoral chondral lesions Pincer FAI Snapping iliopsoas tendon
n 32 26 (Outerbridge grade IV in 12, grade III in 17, grade II in 1, and grade I in 6) 16 12 8 7 2 1 (grade I) 1 1
FAI, femoroacetabular impingement.
velocity, durability, and performance. However, our evaluation of the available data has not shown any findings to support this hypothesis. The duration of symptoms in pitchers with stride-leg problems (29 months) was actually longer than that in pitchers with involvement of the push leg (15 months). Moreover, there was no correlation with pitchers who required inseason surgery versus those who were able to electively undergo off-season procedures. For batters, intuitively, we might have anticipated more problems with the front leg, which is forced into internal rotation during the swing, but our data did not support this. Studies have shown that higher-caliber hitters have a larger angular velocity of the hip, but they looked at the entire hip segment and did not isolate the front leg from the back leg.7 Among the 22 position players, there was a disproportionate number of catchers (n ¼ 6), as might be expected given the extremes of repetitive flexion necessitated by the catcher’s position. Interestingly, there was also a high prevalence of third basemen (n ¼ 6). We have no explanation for this other than, perhaps, sample error associated with a relatively small number of position players (n ¼ 22). The players undergoing repeat arthroscopy represented a heterogeneous subgroup consistent with the varied nature of the disorders for which the overall group of baseball players was treated. One professional player underwent repeat arthroscopy 5 months after Table 2. Procedures Performed Labral debridement Femoroplasty Chondroplasty Acetabuloplasty Labral refixation Loose body removal Iliopsoas release Labral repair
n 30 28 27 (including 10 microfractures) 13 9 7 1 1
1509
labral repair because of residual symptoms that kept him from playing. At arthroscopy, the repair site was fully healed, with only some capsulolabral adhesions encountered. A collegiate player underwent a second arthroscopic procedure for recurrent symptoms 1 year after correction of pincer and cam impingement with labral refixation and microfracture for grade IV articular damage to the acetabulum. The second-look procedure showed significant partial failure of the previous microfracture site. A professional pitcher underwent arthroscopy of both hips 3 years apart. One side included femoroplasty for cam impingement with debridement and microfracture for a grade IV acetabular lesion. The other side included femoroplasty and acetabuloplasty with labral refixation. He underwent repeat arthroscopy of each side 1 year after the index procedures, with scarring and mild progression of chondromalacia. The insight offered from this work is meaningful because of the paucity of literature on the subject. Only one other study has been published reporting on hip disorders in overhead athletes. Klingenstein et al.17 reported on a mixed group of 34 high school, college, and professional lacrosse and baseball players. Their postoperative results showed a modified Harris Hip Score of 92 points on average, which was slightly lower than that in our study. However, their improvement of 22 points was greater because of a lower preoperative baseline score of 70 points. An explanation for these differences could be that their group was functioning at a lower level than the collegiate and professional athletes reported in our study, combined with the ceiling effect of the modified Harris Hip Score. Regardless, their observations are comparable with those of this study, with a significant improvement in outcome scores and successful return to sport. The mean improvement among the high-level baseball players in our study (13 points) is less than what we have previously published among athletes and nonathletes (range, 20.5 to 45 points).1,12,18,19 However, the overall improvement (94 points) is comparable with these previous studies (range, 81 to 96 points). The differences in the amount of improvement were a result of the much lower preoperative baseline scores in these previous studies (range, 51 to 72 points) compared with those in the baseball players in this study (81 points), reflecting the higher level of function in the baseball group. Limitations This study has 3 significant limitations. First, although it is a strength that all procedures were performed by a single surgeon and the study includes all-comers, the group of baseball players is very heterogeneous. The study spans 3 decades, during which the understanding of hip pathology and pathomechanics evolved,
1510
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especially in reference to femoroacetabular impingement; moreover, technology has progressed, especially in the realm of labral preservation. Thus this report shows generalities, commenting only on observations regarding the role of hip disorders and disability from baseball and the role of arthroscopic intervention in addressing this disability. It does not attempt to offer specific treatment strategies that would be based on the most current methods. Second, the modified Harris Hip Score, although a validated outcome instrument, shows a significant ceiling effect, limiting its usefulness in reflecting athletic performance.20 This score is clinically relevant, correlating with patient satisfaction, although it can be overestimated with high scores.21 Newer tools, such as the International Hip Outcome Tool (iHOT), will more precisely reflect these parameters in the future.22 Lastly, this study reports on the return to baseball but not durability, that is, how long athletes continued to play. However, there are numerous variables that influence this information, including completion of collegiate careers, retirement, athletic ability, and other injuries.
Conclusions This study supports the idea that arthroscopic treatment for a variety of hip pathologies in high-level baseball players provides a successful return to sport and improvement in functional outcome scores.
References 1. Byrd JWT, Jones KS. Arthroscopic management of femoroacetabular impingement (FAI) in athletes. Am J Sports Med 2011;39:7S-13S. 2. Byrd JWT, Jones KS. Arthroscopic “femoroplasty” in the management of cam-type femoroacetabular impingement. Clin Orthop Relat Res 2009;467:739-746. 3. Bedi A, Dolan M, Leunig M, Kelly BT. Static and dynamic mechanical causes of hip pain. Arthroscopy 2011;27: 235-251. 4. Pappas AM, Zawack RM, Sullivan TJ. Biomechanics of baseball pitching. Am J Sports Med 1986;13:216-222. 5. Welch CM, Banks SA, Cook FF, Draovitch P. Hitting a baseball: A biomechanical description. J Orthop Sports Phys Ther 1995;22:193-201. 6. Guido JA Jr, Werner SL. Lower-extremity ground reaction forces in collegiate baseball pitchers. J Strength Cond Res 2012;26:1782-1785.
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