Incidence of lateral meniscus injury in professional basketball players MICHAEL B.
KRINSKY,*† MD, THOMAS E. ABDENOUR,‡ MA, ATC, STARKEY,§ PhD, ATC, ROBERT A. ALBO,‡ MD,
CHAD
AND DONALD A.
CHU,∥ PhD, RPT,
ATC
From the *Associated
Orthopedic Surgeons of Hayward, Castro Valley, California, §Northeastern University, Boston, Massachusetts, ∥ California State University of Hayward, Hayward, California, and ‡Oakland, California In basketball, injury to the meniscus may occur from either contact or noncontact mechanisms.3,4,6,7 Wroble et al.6 postulate that the meniscus may be prone to injury from repetitive submaximal microtrauma that might lead to a symptomatic tear. Therefore, the running involved in basketball, combined with stopping, cutting, changing direction, and other rotation activities such as pivoting, may all be potential contributors to meniscus injury. At the professional level, Apple et al.2 report that basketball players are more likely to sustain an injury during a game than in practice. Thus, professional players may have a greater exposure to injury because a professional season has approximately four times as many games as a typical collegiate season. The purpose of this study was to determine the incidence of lateral meniscus injury in professional basketball players in the National Basketball Association over a 6-year period and to draw conclusions regarding higher injury rates for professional players than those currently predicted in existing literature for basketball players in
ABSTRACT We reviewed National Basketball Trainers Association data over a 6-year period to determine the incidence of lateral meniscus injury among professional basketball players. Our results indicated that 58% of all injuries involved the lateral meniscus, while 42% involved the medial meniscus. This differs from what other authors have reported for basketball players. The lateral meniscus may be vulnerable to chronic injury and subject to microtrauma from repetitive submaximal stresses associated with cutting or changing direction while running, or from pivoting. A professional player is at more risk of injury during a game than practice, and thus is exposed to injury more than a collegian because the professional season has three to four times as many games. Also, magnetic resonance imaging may aid the physician in accurately diagnosing some tears that would otherwise have gone undetected or required arthroscopy for diagnosis. In addition, injury to the lateral meniscus could produce secondary symptoms such as instability or patellofemoral pain to structures other than the lateral meniscus.
general. MATERIALS AND METHODS We reviewed injury records maintained by the National Basketball Trainers’ Association (NBTA) for the 1983 to 1989 seasons for all meniscal injuries. The database was composed of those injuries occurring to players in the National Basketball Association (NBA) that (1) required physician referral and prescription medication, (2) caused one game or three practices to be missed, or (3) required extraordinary care or treatment, such as multiple daily evaluation and therapy modality treatments. These records were based on information contained in league injury report forms that were completed by each team’s athletic trainer. Primary information in each report form pertained to the injury diagnosis, activity at the time of injury, time lost from
Traditional epidemiologic studies report that injuries to the medial meniscus occur more frequently than injuries to the lateral meniscus.’ It is generally accepted that the greater freedom of movement of the lateral meniscus accounts for this. Functionally, the lateral meniscus plays a key role in the distribution of forces within the joint and aids in joint stability.’ Injury to this structure could compromise joint stability and cause inflammation. t Address correspondence and reprint requests to: Michael B. Krinsky, MD, Orthopedic Team Physician, Golden State Warriors, 19842 Lake Chabot Road, Castro Valley, CA 94546. 17
18
in games and practices because of the injury, and if surgery was performed. Relevant secondary information included the personal background of each player, such as age, number of years playing experience in the NBA, position, height, weight, and the cut of shoe (high, mid, or low cut) being worn at the time of the injury. These records have been maintained at a central source and are reviewed annually by the NBTA and NBA Society of Physicians. The scope of this study did not limit responses to isolated meniscus injuries, but did exclude soft tissue sprains, trauma, or overuse injuries that did not specifically involve a menis-
participation
cus
injury.
RESULTS Data collected for this study were from responses from 19 teams, which represented 76% of the existing NBA teams during this 6-year period. There were 38 meniscal injuries reported involving 36 players. Review of the data indicated that 22 (58%) of the injuries involved the lateral meniscus and 16 (42%) were to the medial meniscus. A t-test of the demographic data showed no significant difference at the 0.05 alpha level between the mean age, playing experience, height, and weight of the players in the two groups
(Table 1).
For those injuries that resulted in practices or games being missed (i.e., surgery performed in season), injuries to the medial meniscus resulted in more practice and game time being lost than did injuries to the lateral meniscus (Table
2). DISCUSSION The findings of this study differ from the findings of Baker and associates.’ In that study of a group of basketball players, only 25% of meniscal injuries were to the lateral meniscus, whereas in this study of NBA professional players the incidence exceeded 50%. TABLE 1
Injury demographics for medial and lateral meniscus injuries to professional basketball players
When comparing professional basketball teams to collegiate teams, distinct differences may be found in both the length of each game and the number of games played in a season. Professional basketball games are 8 minutes longer and the length of the season may be three or four times as great as their collegiate counterparts. As noted, at the professional level the greatest exposure to injury was during competition rather than practice. If there is a nonlocking microtear, it could be exaccerbated by the subacute torsional stresses associated with cutting, rotational pivoting, or defensive shuffling and sliding. Basketball players, in general, perform repetitive noncontact activities, but the professional players repeat them more times during their longer season, and thus are more at risk for developing this pathology. Diagnostic procedures have improved dramatically during the 1980s, and this may have a role in the reporting of lateral meniscus injuries in professional basketball. The chronological history of diagnostics has been progression from the arthrogram to the arthroscope, and now to magnetic reso-
imaging (MRI). compared to arthroscopy, Polly et al.5 reported a 90% accuracy rate of diagnosing lateral meniscus damage using MRI by dividing the number of studies by the sum of the true-positive plus the true-negative results. Consequently, early use of the MRI can detect damage to the lateral meniscus in the subacute phase. Yocum and associates’ attempted to better define the role of the lateral meniscus as stabilizer and their findings have implications for the basketball player that has had a lateral meniscectomy. They reported 62% of the patients that had a complete meniscectomy for an isolated lateral meniscus tear developed postoperative instability, and that in general a poor result was more likely if there was a prolonged delay from the onset of the symptoms until surgery. In addition, 77% of the players lost some passive motion in the involved knee and 58% had crepitation elicited with patellofemoral nance
When
compression. CONCLUSIONS
study of injuries to professional basketball players over 6-year period showed a greater frequency of injury to the lateral meniscus than was reported in basketball players in general. This frequency was also higher than what might be predicted based on traditional information.’ One explanaOur a
TABLE 2 Practices and games missed due to medial and lateral meniscal injuries
° P < 0.05. b P < 0.01.
tion for this situation is that the biomechanics of the lateral meniscus leave it vulnerable to chronic damage resulting from repetitive microtrauma, a function of exposure to injury. A professional basketball player is more likely to be injured in a game and plays significantly more games than his collegiate counterpart. Also, the use of MRI enables the physician to detect meniscal damage in the subacute phase of the injury. Some of the consequences of lateral meniscectomy include increased joint laxity and patellofemoral pain, either of which could compromise the abilities of an effective
professional player.
19 2.
ACKNOWLEDGMENT
3.
The authors thank Dr. Jamil Sulieman for his assistance in the preparation of this paper.
4.
5.
REFERENCES 1. American medicine.
6. of
Academy Orthopedic Surgeons: Chicago, AAOS, 1985, p 282
Athletic
training
and sports
7.
Apple DF, O’Toole J, Annis C: Professional basketball injuries. Physician Sportsmed 10: 81-86, 1982 Baker BE, Peckham AC, Pupparo F, et al: Review of meniscal injury and associated sports. Am J Sports Med 13: 1-4, 1985 Malone TR: Basketball injuries and treatment. Baltimore, Williams & Wilkins, 1988, p 52 Polly DW, Callaghan JJ, Sikes RA, et al: The accuracy of selective magnetic resonance imaging compared with the findings of arthroscopy of the knee. J Bone Joint Surg 70A: 192-198, 1988 Wroble RR, Mysnyk MC, Foster DT, et al: Patterns of knee injuries in wrestling: A six year study. Am J Sports Med 14: 55-66, 1986 Yocum LA, Kerlan RK, Jobe FW, et al: Isolated lateral meniscectomy. J Bone Joint Surg 61A: 338-342, 1978
KRINSKY,*† MD, THOMAS E. ABDENOUR,‡ MA, ATC, STARKEY,§ PhD, ATC, ROBERT A. ALBO,‡ MD,
CHAD
AND DONALD A.
CHU,∥ PhD, RPT,
ATC
From the *Associated
Orthopedic Surgeons of Hayward, Castro Valley, California, §Northeastern University, Boston, Massachusetts, ∥ California State University of Hayward, Hayward, California, and ‡Oakland, California In basketball, injury to the meniscus may occur from either contact or noncontact mechanisms.3,4,6,7 Wroble et al.6 postulate that the meniscus may be prone to injury from repetitive submaximal microtrauma that might lead to a symptomatic tear. Therefore, the running involved in basketball, combined with stopping, cutting, changing direction, and other rotation activities such as pivoting, may all be potential contributors to meniscus injury. At the professional level, Apple et al.2 report that basketball players are more likely to sustain an injury during a game than in practice. Thus, professional players may have a greater exposure to injury because a professional season has approximately four times as many games as a typical collegiate season. The purpose of this study was to determine the incidence of lateral meniscus injury in professional basketball players in the National Basketball Association over a 6-year period and to draw conclusions regarding higher injury rates for professional players than those currently predicted in existing literature for basketball players in
ABSTRACT We reviewed National Basketball Trainers Association data over a 6-year period to determine the incidence of lateral meniscus injury among professional basketball players. Our results indicated that 58% of all injuries involved the lateral meniscus, while 42% involved the medial meniscus. This differs from what other authors have reported for basketball players. The lateral meniscus may be vulnerable to chronic injury and subject to microtrauma from repetitive submaximal stresses associated with cutting or changing direction while running, or from pivoting. A professional player is at more risk of injury during a game than practice, and thus is exposed to injury more than a collegian because the professional season has three to four times as many games. Also, magnetic resonance imaging may aid the physician in accurately diagnosing some tears that would otherwise have gone undetected or required arthroscopy for diagnosis. In addition, injury to the lateral meniscus could produce secondary symptoms such as instability or patellofemoral pain to structures other than the lateral meniscus.
general. MATERIALS AND METHODS We reviewed injury records maintained by the National Basketball Trainers’ Association (NBTA) for the 1983 to 1989 seasons for all meniscal injuries. The database was composed of those injuries occurring to players in the National Basketball Association (NBA) that (1) required physician referral and prescription medication, (2) caused one game or three practices to be missed, or (3) required extraordinary care or treatment, such as multiple daily evaluation and therapy modality treatments. These records were based on information contained in league injury report forms that were completed by each team’s athletic trainer. Primary information in each report form pertained to the injury diagnosis, activity at the time of injury, time lost from
Traditional epidemiologic studies report that injuries to the medial meniscus occur more frequently than injuries to the lateral meniscus.’ It is generally accepted that the greater freedom of movement of the lateral meniscus accounts for this. Functionally, the lateral meniscus plays a key role in the distribution of forces within the joint and aids in joint stability.’ Injury to this structure could compromise joint stability and cause inflammation. t Address correspondence and reprint requests to: Michael B. Krinsky, MD, Orthopedic Team Physician, Golden State Warriors, 19842 Lake Chabot Road, Castro Valley, CA 94546. 17
18
in games and practices because of the injury, and if surgery was performed. Relevant secondary information included the personal background of each player, such as age, number of years playing experience in the NBA, position, height, weight, and the cut of shoe (high, mid, or low cut) being worn at the time of the injury. These records have been maintained at a central source and are reviewed annually by the NBTA and NBA Society of Physicians. The scope of this study did not limit responses to isolated meniscus injuries, but did exclude soft tissue sprains, trauma, or overuse injuries that did not specifically involve a menis-
participation
cus
injury.
RESULTS Data collected for this study were from responses from 19 teams, which represented 76% of the existing NBA teams during this 6-year period. There were 38 meniscal injuries reported involving 36 players. Review of the data indicated that 22 (58%) of the injuries involved the lateral meniscus and 16 (42%) were to the medial meniscus. A t-test of the demographic data showed no significant difference at the 0.05 alpha level between the mean age, playing experience, height, and weight of the players in the two groups
(Table 1).
For those injuries that resulted in practices or games being missed (i.e., surgery performed in season), injuries to the medial meniscus resulted in more practice and game time being lost than did injuries to the lateral meniscus (Table
2). DISCUSSION The findings of this study differ from the findings of Baker and associates.’ In that study of a group of basketball players, only 25% of meniscal injuries were to the lateral meniscus, whereas in this study of NBA professional players the incidence exceeded 50%. TABLE 1
Injury demographics for medial and lateral meniscus injuries to professional basketball players
When comparing professional basketball teams to collegiate teams, distinct differences may be found in both the length of each game and the number of games played in a season. Professional basketball games are 8 minutes longer and the length of the season may be three or four times as great as their collegiate counterparts. As noted, at the professional level the greatest exposure to injury was during competition rather than practice. If there is a nonlocking microtear, it could be exaccerbated by the subacute torsional stresses associated with cutting, rotational pivoting, or defensive shuffling and sliding. Basketball players, in general, perform repetitive noncontact activities, but the professional players repeat them more times during their longer season, and thus are more at risk for developing this pathology. Diagnostic procedures have improved dramatically during the 1980s, and this may have a role in the reporting of lateral meniscus injuries in professional basketball. The chronological history of diagnostics has been progression from the arthrogram to the arthroscope, and now to magnetic reso-
imaging (MRI). compared to arthroscopy, Polly et al.5 reported a 90% accuracy rate of diagnosing lateral meniscus damage using MRI by dividing the number of studies by the sum of the true-positive plus the true-negative results. Consequently, early use of the MRI can detect damage to the lateral meniscus in the subacute phase. Yocum and associates’ attempted to better define the role of the lateral meniscus as stabilizer and their findings have implications for the basketball player that has had a lateral meniscectomy. They reported 62% of the patients that had a complete meniscectomy for an isolated lateral meniscus tear developed postoperative instability, and that in general a poor result was more likely if there was a prolonged delay from the onset of the symptoms until surgery. In addition, 77% of the players lost some passive motion in the involved knee and 58% had crepitation elicited with patellofemoral nance
When
compression. CONCLUSIONS
study of injuries to professional basketball players over 6-year period showed a greater frequency of injury to the lateral meniscus than was reported in basketball players in general. This frequency was also higher than what might be predicted based on traditional information.’ One explanaOur a
TABLE 2 Practices and games missed due to medial and lateral meniscal injuries
° P < 0.05. b P < 0.01.
tion for this situation is that the biomechanics of the lateral meniscus leave it vulnerable to chronic damage resulting from repetitive microtrauma, a function of exposure to injury. A professional basketball player is more likely to be injured in a game and plays significantly more games than his collegiate counterpart. Also, the use of MRI enables the physician to detect meniscal damage in the subacute phase of the injury. Some of the consequences of lateral meniscectomy include increased joint laxity and patellofemoral pain, either of which could compromise the abilities of an effective
professional player.
19 2.
ACKNOWLEDGMENT
3.
The authors thank Dr. Jamil Sulieman for his assistance in the preparation of this paper.
4.
5.
REFERENCES 1. American medicine.
6. of
Academy Orthopedic Surgeons: Chicago, AAOS, 1985, p 282
Athletic
training
and sports
7.
Apple DF, O’Toole J, Annis C: Professional basketball injuries. Physician Sportsmed 10: 81-86, 1982 Baker BE, Peckham AC, Pupparo F, et al: Review of meniscal injury and associated sports. Am J Sports Med 13: 1-4, 1985 Malone TR: Basketball injuries and treatment. Baltimore, Williams & Wilkins, 1988, p 52 Polly DW, Callaghan JJ, Sikes RA, et al: The accuracy of selective magnetic resonance imaging compared with the findings of arthroscopy of the knee. J Bone Joint Surg 70A: 192-198, 1988 Wroble RR, Mysnyk MC, Foster DT, et al: Patterns of knee injuries in wrestling: A six year study. Am J Sports Med 14: 55-66, 1986 Yocum LA, Kerlan RK, Jobe FW, et al: Isolated lateral meniscectomy. J Bone Joint Surg 61A: 338-342, 1978
