Reported Prevalence of Radiographic Cam Deformity Based on Sport: A Systematic Review of the Current Literature

Abstract

Background:Repetitive loading and shear stress across the proximal femur account for the high prevalence of cam deformity in athletes.Purpose:To systematically review the literature to identify the reported number, age, mean alpha angle measurements, and differences between male and female athletes with radiographic cam deformity based on sport.Study Design:Systematic review; Level of evidence, 4.Methods:A systematic review was conducted of studies in the literature between January 1990 and March 2018 that reported on athletes with radiographic cam deformity based on sport. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed, and PubMed, Biosis Previews, SPORTDiscus, PEDro, and EMBASE databases were used. Inclusion criteria included studies documenting radiographic cam deformity based on alpha angle measurements categorized according to the athlete’s primary sport and according to sex. Exclusion criteria were (1) studies not documenting primary sport, (2) studies not reporting total number of athletes with radiographic cam deformity, and (3) studies not separating cam deformity based on sex or using alpha angle measurements. Statistical analysis was used to compare mean reported age and alpha angle measurements between males and females.Results:A total of 28 studies consisting of 1160 male and 53 female athletes with radiographic cam deformity were identified. Cam lesions were most commonly reported in soccer athletes among both males and females, followed by hockey and American football. Male athletes had significantly higher mean alpha angle measurements (59.9° ± 5.5°) compared with female athletes (48.3° ± 6.9°) (P = .001). No significant difference in age was appreciated between males (21.1 ± 4.0 years) and females (21.7 ± 3.0 years) (P = .62).Conclusion:Radiographic cam deformity is most commonly reported in athletes participating in soccer and hockey. Males possessed significantly greater mean alpha angle measurements compared with females, whereas no significant difference in mean age at the time of diagnosis was appreciated between sexes.

Characteristics of Soccer Players Undergoing Primary Hip Arthroscopy for Femoroacetabular Impingement: A Sex- and Competitive Level–Specific Analysis

“…While the reason for these differences in the development of cam morphology (measured by the alpha angle) is not clear, some have hypothesized that sex differences in the development of cam morphology may be attributed to higher stresses seen in the male hip because of the increased number of males participating in higher-risk and higher-impact sports (hockey, American football, soccer). 18 However, our findings evaluating soccer players rule out this theory and show that female soccer players, even the highly competitive among them, have lower alpha angles as compared with their male counterparts. On the basis of these findings, we suggest a different theory for these differences.…”

“…It has been established that soccer is a stressful sport for the hip, 4,14,18,23,24 as running, cutting movements, and kicking are the most common activities on the soccer field. Kicking is an impinging movement similar to the impingement test (FADIR), and it may be the most significant contributor to the high stresses across the hip during soccer.…”

“…4,22 Specifically, soccer is the most common sport with reports of athletes having radiographic FAI morphology. 18 More than 200 million players in >200 countries play the sport of soccer, making it the most popular sport in the world. 10 Aside from cutting and running, the most repetitive movement in soccer is kicking, which involves forced hip flexion, adduction, and external/internal rotation 14,16,18 which is comparable with maneuvers used to provoke symptomatic hip impingement.…”

“…18 More than 200 million players in >200 countries play the sport of soccer, making it the most popular sport in the world. 10 Aside from cutting and running, the most repetitive movement in soccer is kicking, which involves forced hip flexion, adduction, and external/internal rotation 14,16,18 which is comparable with maneuvers used to provoke symptomatic hip impingement. A higher prevalence of radiographic FAI deformities has been shown in young male club soccer players 2 and professional male soccer players 7 when compared with nonathletic controls of the same age.…”

Improvements After Arthroscopic Treatment for Femoroacetabular Impingement Syndrome in High-Level Ice Hockey Players: 2-Year Outcomes by Player Position

“…Femoroacetabular impingement syndrome (FAIS) is a common cause of hip pain in athletes and ice hockey players in particular. 4 , 5 , 13 Arthroscopic treatment for FAIS is associated with decreased pain and improved function for athletes in general, 6 , 28 , 29 , 31 and a large number of ice hockey players undergo arthroscopic treatment for FAIS. 21 However, little is known about self-reported hip function after arthroscopic treatment for FAIS in ice hockey players and whether ice hockey–related demographics are related to self-reported outcomes or side of symptoms.…”