The relationship between the frequency of football practice during skeletal growth and the presence of a cam deformity in adult elite football players

Associations Between Hip Pathology, Hip and Groin Pain, and Injuries in Hockey Athletes: A Clinical Commentary

Femoroacetabular impingement (FAI), particularly cam morphology, is highly prevalent among elite hockey athletes. Moreover, hip and groin pain has become a common issue in hockey, with approximately 50% of European professional athletes reported to experience a hip or groin problem during a season. While most athletes will not miss training or competition due to this, restricted competitive performance and increased risk of reduced physical and psychological well-being are likely. Recent research suggests that the development of cam morphology is related to the repetitive shear stresses experienced at the hip joint during adolescence from skating. This condition likely increases the potential for intra-articular and extra-articular injuries in these athletes later in their careers. Research also indicates that the hip joint mechanics during forward skating substantially increase the possibility of sustaining a labral tear compared to other sports. Such an injury can increase femoral head movement within the joint, potentially causing secondary damage to the iliofemoral ligament, ligamentum teres and joint capsule. These injuries and the high density of nociceptors in the affected structures may explain the high prevalence of hip and groin pain in hockey athletes. Compensatory adaptations, such as reduced hip strength, stability, and range-of-motion (ROM) likely increase the opportunity for core muscle injuries and hip flexor and adductor injuries. Specifically, the limited hip ROM associated with cam morphology appears to exacerbate the risk of these injuries as there will be an increase in pubic symphysis stress and transverse strain during rotational movements. It is hoped that this article will assist practitioners currently working with hockey athletes to develop evidence-informed monitoring strategies and training interventions, aimed at reducing the incidence and severity of hip and groin problems, ultimately enhancing athlete performance and well-being. Therefore, the purpose of this clinical commentary was to examine current evidence on common hip pathologies in hockey athletes, exploring potential associations between hip and groin pain and the biomechanics of hockey activities.

Level of Evidence

5.

Lost in research translation: Female athletes are not male athletes, especially at the hip

Altered shape of the proximal femur (cam morphology) or acetabulum (pincer morphology) is indicative of femoroacetabular impingement, which can result in hip pain and osteoarthritis of the hip. As mechanical load during growth affects the resulting bone shape, there is strong evidence in males that cam morphology develops during skeletal growth while physes are open, rather than as an adaptation after growth plates are closed (skeletal maturity). This adaptation is particularly evident in athletes who participate at elite levels prior to skeletal maturity. The research providing this evidence, however, has primarily focused on male athletes. Despite the lack of inclusion in the research, females consistently comprise two thirds of the clinical and surgical populations with structural hip pain or pathology. Knowledge gained from male-dominated cohorts may not appropriately transfer to female athletes, especially at the hip. This perspectives article briefly reviews differences between females and males in femoral and acetabular structure, hormones, timing of puberty/maturation, hypermobility, activity level and movement control-factors which affect hip structure development and loading. Without female-focused research, the application of research findings from male athletes to female athletes may lead to ineffective or even inappropriate recommendations and treatments. Thus, there is a critical need for investment in research to promote life-long hip health for females.

Moderate and High Sport Specialization Level in Ice Hockey Athletes Is Associated With Symptomatic Cam Deformity

BACKGROUND

There is a known association between ice hockey and cam deformity in growing athletes. Similarly, the association between sport specialization and overuse injury in youth athletes has been well established. Limited research exists examining the relationship between cam deformity and sport specialization.

HYPOTHESIS/PURPOSE

Our hypothesis was that there would be a positive association with cam deformity and sport specialization category.

STUDY DESIGN

Retrospective chart review and cross-sectional questionnaire study.

LEVEL OF EVIDENCE

Level 4.

METHODS

Study participants included athletes aged 15 to 25 years with symptomatic femoroacetabular impingement (FAI) and considered ice hockey as their primary sport. All participants had completed Dunn lateral radiographs or hip magnetic resonance imaging as part of their clinical evaluation. All participants completed a survey regarding sport specialization level. Multivariable linear regression analysis controlling for sex was used to analyze the association between degree of sport specialization, age of sport specialization, position played, and level played. Comparisons in radiographic parameters across ice hockey groups were conducted using Student t tests and chi-square tests.

RESULTS

Sixty-six ice hockey participants made up the cohort. The majority reported high sport specialization (41/66, 62%). The mean age of sport specialization was 10.7 years (SD 3.5). Participants with moderate specialization had 25 times the odds of a cam deformity (odds ratio [OR] 25.2; 95% CI 1.5-410.7; P = 0.02) and those with high specialization had 9 times the odds of cam deformity (OR 9.3; 95% CI 1.2-74.2; P = 0.04) compared with those with a low degree of specialization, controlling for patient sex. No association was detected between the age of specialization and the likelihood of cam deformity when controlling for patient sex.

CONCLUSION

Level of sport specialization was associated with a cam deformity in this cohort of youth ice hockey athletes.

CLINICAL RELEVANCE

This study suggests that an association exists.

Open and arthroscopic management of femoroacetabular impingement: a review of current concepts

Femoroacetabular impingement (FAI) is a common femoral and/or acetabular abnormality that can cause progressive damage to the hip and osteoarthritis. FAI can be the result of femoral head/neck overgrowth, acetabular overgrowth or both femoral and acetabular abnormalities, resulting in a loss of native hip biomechanics and pain upon hip flexion and rotation. Radiographic evidence can include loss of sphericity of the femoral neck (cam impingement) and/or acetabular retroversion with focal or global overcoverage (pincer impingement). Operative intervention is indicated in symptomatic patients after failed conservative management with radiographic evidence of impingement and minimal arthritic changes of the hip, with the goal of restoring normal hip biomechanics and reducing pain. This is done by correcting the femoral head-neck relationship to the acetabulum through femoral and/or acetabular osteoplasty and treatment of concomitant hip pathology. In pincer impingement cases with small lunate surfaces, reverse periacetabular osteotomy is indicated as acetabular osteoplasty can decrease an already small articular surface. While surgical dislocation is regarded as the traditional gold standard, hip arthroscopy has become widely utilized in recent years. Studies comparing both open surgery and arthroscopy have shown comparable long-term pain reduction and improvements in clinical measures of hip function, as well as similar conversion rates to total hip arthroplasty. However, arthroscopy has trended toward earlier improvement, quicker recovery and faster return to sports. The purpose of this study was to review the recent literature on open and arthroscopic management of FAI.

The natural history of alpha angle in the last seventeen centuries

INTRODUCTION

Hip osteoarthritis is one of the most important and debilitating diseases affecting thousands of people all over the world. On the other hand, femoroacetabular impingement (FAI) is one of the known important causes of hip osteoarthritis. Cam deformity frequently presents in FAI showing an increased alpha angle. Increased alpha angle has been observed among young patients involved in demanding physical activities such as in sports (40-60%), whereas among the non-athletic population, increased alpha angle was observed in 15-20%. Although femoroacetabular pathology has been described over the recent years, it is not possible to determine when the angle increase actually begins prior to diagnosis. The aim of our study is to evaluate the femoral alpha angle in different human femurs in different civilization eras in West Mediterranean area.

MATERIALS AND METHODS

Available ancient femurs were selected from the Collection Center belonging to the archeological archives (ancient necropolis) from the fourth, fourteenth and eighteenth centuries. A comparison of the alpha angle was made of the measurements from the different groups accompanied by a sample of present-day femurs from the radiology database of CT scans. Data from 243 femoral bones were collected, 50 of which from the fourth century, 26 from the fourteenth century, 68 from the eighteenth century, and 99 femurs from the 20/twenty-first century.

RESULTS

Alpha angles in all historical samples showed pathological values (> 55º) up to a maximum of 11.5% of the cases. Meanwhile, the actual series showed pathological alpha angle in 60.1% of the cases with statistical significant differences.

CONCLUSION

The studied femurs of the western Mediterranean region from the fourth, fourteenth and eighteenth centuries showed pathological alpha angles in a smaller proportion than the actual sample.

LEVEL OF EVIDENCE

Level III, retrospective studies.

Prospective evaluation of sport activity and the development of femoroacetabular impingement in the adolescent hip (PREVIEW): results of the pilot study

Background

The purpose of this pilot study was to validate the feasibility of a definitive study aimed at determining if high-intensity physical activity during adolescence impacts the development of femoroacetabular impingement (FAI).

Methods

This prospective cohort pilot study had a sample size target of 50 volunteers between 12 and 14 years old at sites in Canada, South Korea, and the Netherlands. Participants were evaluated clinically and radiographically at baseline and at 2 years. The participants’ sport and physical activity were evaluated using the Habitual Activity Estimation Scale (HAES) and the American Orthopaedic Society for Sports Medicine (AOSSM) criteria for sport specialization. The primary outcome was feasibility and secondary outcomes included the incidence of radiographic FAI and hip range of motion, function (Hip Outcome Score, HOS), and quality of life (Pediatric Quality of Life questionnaire, PedsQL) at 24 months. Study groups were defined at the completion of follow-up, given the changes in participant activity levels over time.

Results

Of the 54 participants enrolled, there were 36 (33% female) included in the final analysis. At baseline, those classified as highly active and played at least one organized sport had a higher incidence of asymptomatic radiographic FAI markers (from 6/32, 18.8% at baseline to 19/32, 59.4% at 24 months) compared to those classified as low activity (1/4, 25% maintained at baseline and 24 months). The incidence of radiographic FAI markers was higher among sport specialists (12/19, 63.2%) compared to non-sport specialists (8/17, 47.1%) at 24 months. The HOS and PedsQL scores were slightly higher (better) among those that were highly active and played a sport compared to those who did not at 2 years (mean difference (95% confidence interval): HOS-ADL subscale 4.56 (− 7.57, 16.70); HOS-Sport subscale 5.97 (− 6.91, 18.84); PedsQL Physical Function 7.42 (− 0.79, 15.64); PedsQL Psychosocial Health Summary 6.51 (− 5.75, 18.77)).

Conclusion

Our pilot study demonstrated some feasibility for a larger scale, definitive cohort study. The preliminary descriptive data suggest that adolescents engaged in higher levels of activity in sports may have a higher risk of developing asymptomatic hip deformities related to FAI but also better quality of life over the 2-year study period.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-022-01164-3.

Does the Type of Sport Influence Morphology of the Hip? A Systematic Review

BACKGROUND

Femoroacetabular impingement (FAI) has been extensively investigated and is strongly associated with athletic participation.

PURPOSE

To assess (1) the prevalence of cam-type FAI across various sports; (2) whether kinematic variation among sports influences hip morphology; and (3) whether performance level, duration, and frequency of participation or other factors influence hip morphology in a sporting population.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic search of Embase, PubMed, and the Cochrane Library was undertaken following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Prospective and retrospective case series, case reports, and review articles published after 1999 were screened, and those that met the inclusion criteria decided a priori were included for analysis.

RESULTS

The literature search identified 58 relevant articles involving 5683 participants. A total of 49 articles described a higher prevalence of FAI across various "hip-heavy" sports, including soccer, basketball, baseball, ice hockey, skiing, golf, and ballet. In studies including nonathlete controls, a greater prevalence of FAI was reported in 66.7% of studies (n = 8/12). The highest alpha angle was identified at the 1-o'clock position (n = 9/9) in football, skiing, golf, ice hockey, and basketball. The maximum alpha angle was located in a more lateral position in goalkeepers versus positional players in ice hockey (1 vs 1:45 o'clock). A positive correlation was also identified between the alpha angle and both age and activity level (n = 5/8 and n = 2/3, respectively) and between prevalence of FAI and both age and activity level (n = 2/2 and n = 4/5).

CONCLUSION

Hip-heavy sports show an increased prevalence of FAI, with specific sporting activities influencing hip morphology. There is some evidence to suggest that a longer duration and higher level of training also result in an increased prevalence of FAI.

REGISTRATION

CRD4202018001 (PROSPERO).

Characterizing femoroacetabular impingement in professional Nordic Skiers

OBJECTIVE

Studies have shown a high prevalence of femoroacetabular impingement (FAI) among elite athletes yet there is a paucity of data on FAI in Nordic skiers. The purpose of this study was to determine the prevalence of radiographic FAI in professional Nordic Combined Skiers and Ski jumpers compared to controls and assess functional outcomes including hip range of motion (ROM) and pain in patients with radiographic evidence of FAI compared to those without it.

METHODS

A cohort of elite Nordic Skiers underwent medical history, physical examination, and pelvic radiographs at their visit with a fellowship-trained sports medicine physician. On pelvis radiographs, Alpha angle>55 degrees was deemed cam-positive, and positive crossover signs, Tönnis<0, or LCEA>40 were deemed pincer positive. Further stratification was performed by sex, ski event type, hip pain, presence of cam lesions, and presence of pincer lesions. Spearman correlation matrix was performed to measure the association between radiographic measurements and ROM.

RESULTS

Nineteen Nordic skiers and nineteen age, sex, and BMI matched controls were included in the study. There were no significant differences in age, sex, BMI, and hip pain between groups. While Nordic skiers demonstrated decreased ROM bilaterally on external rotation compared to controls, skiers had larger ROM bilaterally on extension, abduction, adduction compared to controls. Skiers were significantly more likely to have bilateral crossover sign and alpha angles>55 compared to controls. Subgroup analysis showed that Cam positive patients had higher flexion and adduction ROM and pincer positive patients had significantly higher flexion and abduction ROM compared to patients without cam and pincer lesions respectively. Patients with hip pain had significantly lower right hip abduction ROM compared to patients without hip pain. No significant correlations were seen between radiographic measurements and ROM.

CONCLUSION

Similar to other elite 'hip heavy' sport athletes, Nordic skiers gave a notably higher prevalence of radiographic cam and pincer type morphology and significantly higher ROM compared to nonathletic controls. Clinicians evaluating Nordic skiers should be aware of these baseline findings with respect to a possible elevated long-term risk of symptomatic FAI in these athletes as well as other conditions related to radiographic FAI.

[Epidemiology, prevention and early detection of femoroacetabular impingement syndrome (FAIS)]

During the last two decades femoroacetabular impingement syndrome (FAIS) has gained importance and is one of the main causes of hip pain in young adults. FAIS is a motion-related clinical pathology of the hip that represents symptomatic contact between the proximal femur and the acetabulum. Symptoms, clinical signs, and imaging findings must be present to diagnose FAIS. Especially the development of the cam-FAIS seems to be associated with an overuse of the growth plate during adolescence. Here an approach may be found for the prevention of the development of FAIS. Sufficient evidence through high-quality long-term results is yet lacking.

Training Management of the Elite Adolescent Soccer Player throughout Maturation

Professional soccer clubs invest significantly into the development of their academy prospects with the hopes of producing elite players. Talented youngsters in elite development systems are exposed to high amounts of sports-specific practise with the aims of developing the foundational skills underpinning the capabilities needed to excel in the game. Yet large disparities in maturation status, growth-related issues, and highly-specialised sport practise predisposes these elite youth soccer players to an increased injury risk. However, practitioners may scaffold a performance monitoring and injury surveillance framework over an academy to facilitate data-informed training decisions that may not only mitigate this inherent injury risk, but also enhance athletic performance. Constant communication between members of the multi-disciplinary team enables context to build around an individual's training status and risk profile, and ensures that a progressive, varied, and bespoke training programme is provided at all stages of development to maximise athletic potential.

Measuring 3D growth plate shape: Methodology and application to cam morphology

Physeal changes corresponding to cam morphology are currently measured using two-dimensional (2D) methods. These methods are limited by definitions of the femoral neck axis and head center that are dependent on the radiographic plane of view. To address these limitations, we developed three-dimensional (3D) methods for analyzing continuous growth plate shape using magnetic resonance imaging scans. These new methods rely on a single definition of the femoral neck axis and head center that are both nondependent on the radiographic plane of view and allow for analysis of growth plate shape across the growth plate surface (performed using statistical parametric mapping). Using our 3D method, we analyzed the position of the growth plate in the femoral head (relative to a plane tangent to the femoral head) and the curvature of the growth plate (relative to a plane through the center of the growth plate) in 9-16-year-old males at risk for cam morphology and their recreationally active peers (n = 17/cohort). These two measurements provide an avenue to separately analyze the effects of these variables in the overall growth plate shape. We detected differences in growth plate shape with age in recreationally active adolescents but did not detect differences between at risk and recreationally adolescents.

A longitudinal cohort study of adolescent elite footballers and controls investigating the development of cam morphology

Cam morphology describes an asphericity of the femoral head that develops during adolescence, is highly prevalent in athletes, and predisposes individuals to future osteoarthritis. However, it’s aetiology remains poorly understood. The aim of this study was to perform 3-year longitudinal follow-up of a control population and football club academy cohort to compare the change in hip and growth plate anatomy between athletes and controls. MRI and questionnaires were used to characterise change in hip and growth plate anatomy and quantify activity levels. 121 male academy footballers and 107 male and female controls participated at baseline. Footballers experienced significantly greater increases in femoral head asphericity (4.83 degrees (95% CI: 2.84 to 6.82), p < 0.001) than controls. A positive correlation existed between activity levels and change in femoral head morphology (coefficient 0.79, p  ≤  0.001). Greatest morphological change occurred in individuals aged 11–12 years at baseline, with no significant change in individuals aged 14 years and older at baseline. Cam morphology development was secondary to soft tissue hypertrophy and lateral growth plate extension. In conclusion, excessive loading of the hip joint through exercise prior to 14 years of age may result in growth plate adaptations causing cam morphology. Potential interventions may include training type and load modification in young adolescent football players.

A multidisciplinary assessment of 320 athletes with long-standing groin pain syndrome in keeping with the Italian consensus agreement: the high incidence and the multiple causes of inguinal and hip pathologies and pubic osteopathy

BACKGROUND

Groin pain syndrome is an important and increasing problem in numerous sports (e.g. soccer, football, ice hockey, handball and rugby). Long-standing groin pain syndrome is a form of groin pain syndrome in which the cohort of symptoms reported by the patient is experienced for a long period, typically for over 12 weeks, and is recalcitrant to any conservative therapy. Long-standing groin pain syndrome is potentially career-ending for elite athletes.

METHODS

A descriptive epidemiological study was carried out on 320 athletes (290 men and 30 women) affected by long-standing groin pain syndrome, following the Guidelines issued by the Groin Pain Syndrome Italian Consensus Conference on terminology, clinical evaluation and imaging assessment of groin pain in athlete.

RESULTS

Amongst the clinical tests for inguinal pathologies, only the External Inguinal Ring Exploration proved conclusive (sensitivity: 0.97; specificity: 0.95; positive predictive value: 0.98; negative predictive value: 0.90; likelihood ratio: 19.4). In testing for adductor tendinopathies, only the Isometric Squeeze with flexed knee and distal resistance (sensitivity: 0.86; specificity: 0.45; positive predictive value: 0.48; negative predictive value: 0.85; likelihood ratio: 5.7) and the Palpatory Test at the pubic insertion of the adductor longus (sensitivity: 0.93; specificity: 0.89; positive predictive value: 0.96; negative predictive value: 0.79; likelihood ratio: 8.5) proved, respectively, useful at times and moderately useful. Among the tests for hip pathologies, only the Flexion Abduction External Rotation Test was seen to be conclusive (sensitivity: 0.90; specificity: 0.93; positive predictive value: 0.98; negative predictive value: 0.72; likelihood ratio: 12.9). In the male population on average, long-standing groin syndrome presents either a single cause or multiple causes in respectively 74% and 26% of cases. Furthermore, almost 58% of all cases traced to a single clinical cause can be attributed to inguinal pathologies alone. Long-standing groin syndrome in the female population shows only one pathological cause with inguinal pathologies, and acetabular labrum tear representing the most frequent etiologies.

CONCLUSIONS

Men and women exhibit different causes for long-standing groin pain syndrome. Several routine tests used in the clinical evaluation of this condition furnish a low likelihood ratio. Consequently, in order to optimize clinical evaluation and minimize patient discomfort, clinical evaluation should be based on tests with a greater likelihood ratio.

How does the cam morphology develop in athletes? A systematic review and meta-analysis

OBJECTIVE

A higher prevalence of cam morphology has been reported in the athletic population but the development of the cam morphology is not fully understood. The purpose of this systematic review is to establish the timing of development of the cam morphology in athletes, the proximal femoral morphologies associated with its development, and other associated factors.

DESIGN

Embase, MEDLINE and the Cochrane Library were searched for articles related to development of the cam morphology, and PRISMA guidelines were followed. Data was pooled using random effects meta-analysis. Study quality was assessed using the Downs and Black criteria and evidence quality using the GRADE framework.

RESULTS

This search identified 16 articles involving 2,028 participants. In males, alpha angle was higher in athletes with closed physes than open physes (SMD 0.71; 95% CI 0.23, 1.19). Prevalence of cam morphology was associated with age during adolescence when measured per hip (β 0.055; 95% CI 0.020, 0.091) and per individual (β 0.049; 95% CI 0.034, 0.064). Lateral extension of the epiphysis was associated with an increased alpha angle (r 0.68; 95% CI 0.63, 0.73). A dose-response relationship was frequently reported between sporting frequency and cam morphology. There was a paucity of data regarding the development of cam morphology in females.

CONCLUSIONS

Very low and low quality evidence suggests that in the majority of adolescent male athletes, osseous cam morphology developed during skeletal immaturity, and that prevalence increases with age. Very low quality evidence suggests that osseous cam morphology development was related to lateral extension of the proximal femoral epiphysis.

Primary cam morphology; bump, burden or bog-standard? A concept analysis

BACKGROUND

Cam morphology, a distinct bony morphology of the hip, is prevalent in many athletes, and a risk factor for hip-related pain and osteoarthritis. Secondary cam morphology, due to existing or previous hip disease (eg, Legg-Calve-Perthes disease), is well-described. Cam morphology not clearly associated with a disease is a challenging concept for clinicians, scientists and patients. We propose this morphology, which likely develops during skeletal maturation as a physiological response to load, should be referred to as primary cam morphology. The aim of this study was to introduce and clarify the concept of primary cam morphology.

DESIGN

We conducted a concept analysis of primary cam morphology using articles that reported risk factors associated with primary cam morphology; we excluded articles on secondary cam morphology. The concept analysis method is a rigorous eight-step process designed to clarify complex 'concepts'; the end product is a precise definition that supports the theoretical basis of the chosen concept.

RESULTS

We propose five defining attributes of primary cam morphology-tissue type, size, site, shape and ownership-in a new conceptual and operational definition. Primary cam morphology is a cartilage or bony prominence (bump) of varying size at the femoral head-neck junction, which changes the shape of the femoral head from spherical to aspherical. It often occurs in asymptomatic male athletes in both hips. The cartilage or bone alpha angle (calculated from radiographs, CT or MRI) is the most common method to measure cam morphology. We found inconsistent reporting of primary cam morphology taxonomy, terminology, and how the morphology is operationalised.

CONCLUSION

We introduce and clarify primary cam morphology, and propose a new conceptual and operational definition. Several elements of the concept of primary cam morphology remain unclear and contested. Experts need to agree on the new taxonomy, terminology and definition that better reflect the primary cam morphology landscape-a bog-standard bump in most athletic hips, and a possible hip disease burden in a selected few.

Hip and Groin Pain in Soccer Players

Purpose  The aim of this article is to illustrate the recent framework necessary to standardize studies on groin pain and review the existing literature on groin pain in football. Methods  The common pathological processes underlying groin pain such as muscle, tendon or ligament strain, bone injury or fracture, sport hernia, bursitis, osteitis pubis, and hip-related diseases have been reviewed and current management options have been considered. Results  Groin pain is considered a pain in pubic or lower abdominal or adductors region which can be monolateral or bilateral. It is common in high-intensity team sports and can negatively affect an athlete's professional carrier, causing serious disruption in the performance. Despite a high prevalence of groin pain in athletes, diagnosis and management of the underlying pathological processes remain a challenge for surgeons, radiologists, and physiotherapists alike. Conclusion  A multidisciplinary approach is essential for patients with groin pain allowing prompt diagnosis and initiation of treatment thus facilitating more rapid return to play and preventing potential long-term sequelae of chronic groin pathology.

A Cam Morphology Develops in the Early Phase of the Final Growth Spurt in Adolescent Ice Hockey Players: Results of a Prospective MRI-based Study

BACKGROUND

Cam morphologies seem to develop with an increased prevalence in adolescent boys performing high-impact sports. The crucial question is at what age the cam morphology actually develops and whether there is an association with an aberration of the shape of the growth plate at the cam morphology site.

QUESTIONS/PURPOSES

(1) What is the frequency of cam morphologies in adolescent ice hockey players, and when do they appear? (2) Is there an association between an extension of the physeal growth plate and the development of a cam morphology? (3) How often do these players demonstrate clinical findings like pain and lack of internal rotation?

METHODS

A prospective, longitudinal MRI study was done to monitor the proximal femoral development and to define the appearance of cam morphologies in adolescent ice hockey players during the final growth spurt. Young ice hockey players from the local boys' league up to the age of 13 years (mean age 12 ± 0.5 years) were invited to participate. From 35 players performing on the highest national level, 25 boys and their parents consented to participate. None of these 25 players had to be excluded for known disease or previous surgery or hip trauma. At baseline examination as well as 1.5 and 3 years later, we performed a prospective noncontrast MRI scan and a clinical examination. The three-dimensional morphology of the proximal femur was assessed by one of the authors using radial images of the hip in a clockwise manner. The two validated parameters were: (1) the alpha angle for head asphericity (abnormal > 60°) and (2) the epiphyseal extension for detecting an abnormality in the shape of the capital physis and a potential correlation at the site of the cam morphology. The clinical examination was performed by one of the authors evaluating (1) internal rotation in 90° of hip and knee flexion and (2) hip pain during the anterior impingement test.

RESULTS

Cam morphologies were most apparent at the 1.5-year follow-up interval (10 of 25; baseline versus 1.5-year follow-up: p = 0.007) and a few more occurred between 1.5 and 3 years (12 of 23; 1.5-year versus 3-year follow-up: p = 0.14). At 3-year follow-up, there was a positive correlation between increased epiphyseal extension and a high alpha angle at the anterosuperior quadrant (1 o'clock to 3 o'clock) (Spearman correlation coefficient = 0.341; p < 0.003). The prevalence of pain on the impingement test and/or restricted internal rotation less than 20° increased most between 1.5-year (1 of 25) and the 3-year follow-up (6 of 22; 1.5-year versus 3-year follow-up: p = 0.02).

CONCLUSION

Our data suggest that a cam morphology develops early during the final growth spurt of the femoral head in adolescent ice hockey players predominantly between 13 to 16 years of age. A correlation between an increased extension of the growth plate and an increased alpha angle at the site of the cam morphology suggests a potential underlying growth disturbance. This should be further followed by high-resolution or biochemical MRI methods. Considering the high number of cam morphologies that correlated with abnormal clinical findings, we propose that adolescents performing high-impact sports should be screened for signs of cam impingement, such as by asking about hip pain and/or examining the patient for limited internal hip rotation.

LEVEL OF EVIDENCE

Level I, prognostic study.

Femoroacetabular impingement: correlation between imaging parameters, sport activity, and chondral damage

BACKGROUND

Femoroacetabular impingement is characterised by an abnormal contact between the acetabulum and the femoral head-neck junction. Femoroacetabular impingement shows three main clinical frameworks: Pincer-FAI, Cam-FAI and Cam-Pincer mixed form. The aim of the study was to investigate the correlation between femoroacetabular impingement, imaging, activity and chondral damages.

METHODS

Forty-one patients, undergoing arthroscopic chondroartroplasty for Cam and Cam-Pincer mixed form were considered. All patients underwent an X-ray hip evaluation (G1 group), while 15 patients also underwent a pelvis MRI evaluation (G2 subgroup). For G1 patients, the superior-inferior offset ratio and alpha angle were calculated from the X-ray examinations. For G2 patients, the antero-posterior offset ratio was also calculated from pelvis MRI. Chondral damage was classified according to the Outerbridge classification.

RESULTS

The superior-inferior offset ratio and the antero-posterior offset ratio were respectively 0.50 ± 0.23 and 0.33 ± 0.19. The α angle predictive for a chondral damage of IV degree was 81.5°.The chondral damage of the patients suffering from Cam-FAI and Cam-Pincer mixed form were respectively 3.53±0.80 and 3.00±1.41.

CONCLUSIONS

From the results was possible to: - Elaborate two tables providing a reliable indirect calculation of the alpha angle. - Establish an alpha angle cut-off value indicative for a IV degree chondral damage. - Show that Pincer-FAI does not represent an aggravating factor for chondral damage - Show that the level of sports activity was related to the severity of chondral damage. - Show that a physically demanding occupation was not an aggravating factor for chondral damage.

The Size and Prevalence of Bony Hip Morphology Do Not Differ Between Football Players With and Without Hip and/or Groin Pain: Findings From the FORCe Cohort

OBJECTIVE

To compare the size and prevalence of bony hip morphology in football players with and without hip and/or groin pain.

DESIGN

Case-control.

METHODS

We recruited 184 soccer and Australian football players with self-reported hip and/or groin pain of greater than 6 months in duration and a positive flexion, adduction, and internal rotation (FADIR) test (290 hips, 21% women), and 55 football players with no pain and a negative FADIR test (110 hips, 26% women) as a control group. Bony hip morphology was identified by the alpha angle and lateral center-edge angle (LCEA) on anteroposterior pelvis and Dunn 45° radiographs. The alpha angle and LCEA were analyzed as continuous measures (size) and dichotomized using threshold values to determine the presence of bony hip morphology (cam, large cam, pincer, and acetabular dysplasia). Regression analyses estimated differences in the size and prevalence of bony hip morphology between football players with and without pain.

RESULTS

In all football players and in men, the size and prevalence of bony hip morphology did not differ between those with and without hip and/or groin pain. Cam morphology was evident in 63% of hips in players without pain and 71% of symptomatic hips in players with hip and/or groin pain. In female football players with hip and/or groin pain compared to those without pain, larger alpha angle values were observed on the Dunn 45° view (5.9°; 95% confidence interval: 1.2°, 10.6°; P = .014).

CONCLUSION

The size and prevalence of bony hip morphology appear to be similar in football players with and without hip and/or groin pain. J Orthop Sports Phys Ther 2021;51(3):115-125. Epub 25 Dec 2020. doi:10.2519/jospt.2021.9622.

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

BACKGROUND

Radiographic features of femoroacetabular impingement (FAI) are prevalent in kicking athletes, especially soccer players. However, there remains a paucity of data on the characteristics of symptomatic soccer players with an established diagnosis of FAI.

PURPOSE

To report on patient demographics, injury, and clinical and radiographic characteristics in a large cohort of soccer players who underwent primary hip arthroscopy for FAI and to perform a sex- and competition level-specific analysis of these data.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

An institutional hip preservation registry containing 3318 consecutive primary hip arthroscopies for FAI performed between March 2010 and January 2016 was retrospectively reviewed for patients identified as soccer players. Patient demographics, injury characteristics, and clinical and radiographic findings were recorded, and sex- and competition level-specific differences were analyzed.

RESULTS

A total of 421 hips (336 soccer players) were identified, including 257 (61.0%) men and 164 (39.0%) women. Of these, 105 (24.9%) were reported as highly competitive, 194 (46.1%) as competitive, 75 (17.8%) as recreational, and 47 (11.2%) did not report a level. The majority of the 336 soccer players (231 hips; 55%) reported chronic hip pain lasting >6 months with no acute injury at the initial visit. Alpha angle, coronal center-edge angle, and femoral version on computed tomography scan measured 64.5°± 12°, 32.3°± 9°, and 13.7°± 10° (mean ± SD), respectively. There were 230 (55%) hips with a type 2 anterior inferior iliac spine (AIIS), 78 (18.5%) with a type 1 AIIS, and 19 (4.5%) with a type 3 AIIS. When compared with male athletes, female athletes had more hip internal rotation on physical examination (14.9° vs 8°; P < .001), lower alpha angles (57.5° vs 68.5°; P < .001), and lower-grade AIIS morphology (P = .003). Acute injury as the reason for hip symptoms was most likely in the highly competitive group (P < .001).

CONCLUSION

Female soccer players were more likely to have less severe clinical and radiographic findings than were male soccer players. Acute injury as the cause of hip symptoms was more common in highly competitive players.

CLINICAL RELEVANCE

Focusing on soccer players with an established FAI diagnosis, the findings of this study suggest that there are sex- and competition level-based differences in the presentation, physical examination, and imaging characteristics among the players. These findings can better guide clinicians in the diagnostic evaluation of symptomatic soccer players with FAI and in tailoring treatment recommendations to specific cohorts.

Hip pain and its correlation with cam morphology in young skiers-a minimum of 5 years follow-up

BACKGROUND

There is conflicting evidence regarding the association between cam morphological changes and hip pain, and it remains unclear who with cam morphology will develop hip pain and who will not. This study aimed to investigate the correlation between cam morphology, hip pain, and activity level at a 5-year follow-up in young Alpine and Mogul skiers.

METHOD

All students (n = 76) at Åre Ski National Sports High School were invited and accepted participation in this prospective study at baseline. Magnetic resonance imaging (MRI) of both hips was conducted to evaluate the presence of cam morphology (α-angle ≥ 55°) and its size alongside the reporting of hip pain, type, and frequency of training by the Back and hip questionnaire, at baseline. After 5 years, the skiers were invited to complete a shortened version of the same questionnaire.

RESULTS

A total of 60 skiers (80%) completed the follow-up questionnaire, of which 53 had concomitant MRI data. Cam morphology was present in 25 skiers (47.2%, 39 hips). Hip pain at baseline and at follow-up was reported in 17 (28.3%) and 22 (36.7%) skiers, respectively. No correlations were found between the activity level, the frequency, and the size of cam morphology and hip pain, except for the right hip α-angle at 1 o'clock and hip pain in skiers with cam morphology at baseline (rs = 0.49; P = 0.03) and at follow-up (rs = 0.47; P = 0.04). A total of 73.3% skiers had retired, of which 48% reported this was due to injuries.

CONCLUSION

Hip pain was not shown to be correlated, or had a low correlation, with activity level and the presence and size of cam morphology in young skiers on a 5-year follow-up. Based on these results, cam morphology or activity level did not affect hip pain to develop during 5 years of follow-up in young skiers. Furthermore, this study highlights that almost 75% of young elite skiers had retired from their elite career with almost 50% reporting that this was due to injuries sustained from skiing.

Using Magneto-Inertial Measurement Units to Pervasively Measure Hip Joint Motion during Sports

The use of wireless sensors to measure motion in non-laboratory settings continues to grow in popularity. Thus far, most validated systems have been applied to measurements in controlled settings and/or for prescribed motions. The aim of this study was to characterize adolescent hip joint motion of elite-level athletes (soccer players) during practice and recreationally active peers (controls) in after-school activities using a magneto-inertial measurement unit (MIMU) system. Opal wireless sensors (APDM Inc., Portland OR, USA) were placed at the sacrum and laterally on each thigh (three sensors total). Hip joint motion was characterized by hip acceleration and hip orientation for one hour of activity on a sports field. Our methods and analysis techniques can be applied to other joints and activities. We also provide recommendations in order to guide future work using MIMUs to pervasively assess joint motions of clinical relevance.

Judokas with low back pain have lower flexibility of the hip-spine complex: A case-control study

OBJECTIVE

Study whether male adult judokas with and without low back pain (LBP) have different hip-spine flexibility.

DESIGN

Cross-sectional.

SETTING

Judo training centres.

PARTICIPANTS

Judokas with (n = 29) and without (n = 33) LBP.

MAIN OUTCOME MEASURES

Range of motion (ROM) (passive and active rotations) of hips, lumbar spine (flexion-extension) and fingertip-to-floor distance (FTFD).

RESULTS

The non-dominant hips of judokas with LBP had 6.8 ± 1.2° (ES:1.45, p < 0.001) lower passive and 8.0 ± 1.3° (ES:1.55, p < 0.001) lower active internal rotation. Dominant hips of judokas with LBP had 5.1 ± 1.6° (ES: 0.81, p = 0.002) lower active internal rotation and 8.8 ± 2.9° (ES:0.79, p = 0.003) lower active total rotation. The LBP group showed 8.0 ± 2.8° (ES: 0.73, p = 0.006) lower flexion and 6.0 ± 2.2° (ES: 0.69, p = 0.009) lower extension of the lumbar spine. The FTFD in the LBP group was 7.3 ± 2.6 cm (ES: 0.72, p = 0.007) lower. The multi-level regression analyses showed passive (OR 1.54, 95%CI 1.18-2.00, p = 0.001) and active (OR 1.47, 95%CI 1.16-1.87, p = 0.001) hip internal rotation of the non-dominant leg and lumbar spinal flexion (OR 1.11, 95%CI 1.03-1.20, p = 0.006) and extension (OR 1.16, 95%CI 1.01-1.33, p = 0.035) were related to LBP.

CONCLUSION

Lower hip internal rotation of the non-dominant leg (passive and active) and lower lumbar flexibility are significantly related to LBP in male adult judokas.

Mirror Image Modeling of Acetabular Rim Thickness Differences in Patients With Unilateral Femoroacetabular Impingement Syndrome

Purpose

To use mirror imaging to identify the location and magnitude of difference in acetabular rim morphology between the symptomatic and unaffected acetabula in patients with symptomatic unilateral pincer-type or mixed femoroacetabular impingement syndrome (FAIS) using 1-dimensional models created with computed tomography (CT).

Methods

CT scans of bilateral hips in 33 patients diagnosed with unilateral pincer-type or mixed FAIS were obtained. Three-dimensional bilateral hip models were constructed, and the unaffected hemipelvis was superimposed onto the symptomatic side to compare acetabular thickness. Protrusion of the symptomatic side was recorded, and rim morphology was divided into clock face quadrants to analyze the location of greatest magnitude of difference between affected and unaffected acetabula. Analysis of the quadrants was performed using analysis of variance with post hoc Bonferroni correction.

Results

The study group consisted of more females (51.6%) than males, with an average age of 35.72 ± 7.8 years and an average body mass index of 24.3 ± 4.1 kg/m². Of the 33 hips included, 14 were isolated pincer-type FAIS and 19 were mixed. The average preoperative symptomatic side lateral center edge angle was 37.5° ± 7.2° compared with 29° ± 5.1° on the asymptomatic side (P = .001). The symptomatic acetabular rim was on average 0.43 ± 0.18 mm thicker than the corresponding location on the unaffected rim. When the acetabulum was divided into clock face quadrants, the 12 to 3 o'clock position showed the greatest difference between symptomatic and unaffected sides (0.55 ± 0.18 mm) compared with the 3 to 6 o'clock position (0.4 ± 0.28 mm; P = .006), 6 to 9 o'clock (0.34 ± 0.07 mm; P < .001), and 9 to 12 o'clock (0.38 ± 0.03; P = .001).

Conclusions

Patients with unilateral, symptomatic pincer-type or mixed FAIS show statistical differences in rim thickness between the affected and unaffected acetabula. Small changes in acetabular rim morphology on the order of ≤0.5 mm may be the difference between symptomatic FAIS and the unaffected hip.

Level of Evidence

IV, case series.

The relationship between cam morphology and hip and groin symptoms and signs in young male football players

Background

Conflicting and limited high‐quality prospective data are available on the associations between cam morphology and hip and groin symptoms and range of motion (ROM).

Objectives

This cross‐sectional cohort study investigated associations between cam morphology presence, size and duration and symptoms and ROM.

Methods

Academy male football players (n = 49, 17‐24 years) were included. Standardized antero‐posterior pelvic and frog‐leg lateral radiographs were obtained at baseline, 2.5‐ and 5‐year follow‐up. The femoral head‐neck junction was quantified by:

Visual score. Cam morphology (flattening or prominence), large cam (prominence).

Alpha angle. Cam morphology (≥60°), large cam (≥78°).

Cam morphology duration was defined as long (first present at baseline) or short (only from 2.5‐ to 5‐year follow‐up). Current symptoms at 5‐year follow‐up were assessed using a hip and groin pain question and by the “Hip and Groin Outcome Score” (HAGOS). HAGOS scores were categorized into: most symptoms (≥2 domains in lowest interquartile range [IQR]), least symptoms (≥2 domains in highest IQR). Hip ROM was measured by goniometry at 5‐year follow‐up.

Results

Large cam morphology based on visual score was associated with hip and groin pain (23.8% vs. 7.1%, OR: 3.17, CI: [1.15‐8.70], P = .026), but not with HAGOS scores. Cam morphology presence, size, and duration were associated with limited flexion of around 6° and/or 3° to 6° for internal rotation.

Conclusion

Cam morphology presence, size, and duration were associated with limited hip flexion and/or internal rotation, but differences might not exceed the minimal clinical important difference. Whether cam morphology results in symptoms is uncertain.

Return to Play in Amateur Soccer Players Undergoing Hip Arthroscopy: Short- to Mid-Term Follow-Up

PURPOSE

To describe patient-reported outcomes (PROs) and return to play at any level in amateur soccer players undergoing hip arthroscopy for femoroacetabular impingement syndrome at short- to mid-term follow-up.

METHODS

Data were prospectively collected and retrospectively reviewed for patients who underwent hip arthroscopy between March 2009 and June 2014. Patients who participated in amateur soccer within 1 year prior to surgery and intended to return to their sport after hip arthroscopy for femoroacetabular impingement syndrome were considered for inclusion in our study. Patients were excluded if they had a preoperative Tönnis osteoarthritis grade of 2 or greater, previous ipsilateral hip conditions or hip surgical procedures, or Workers' Compensation status. The patients from the initial group who had preoperative and minimum 2-year postoperative measures for the modified Harris Hip Score, Non-Arthritic Hip Score, Hip Outcome Score-Sports Specific Subscale, and visual analog scale for pain were included in our final group. In addition to PROs, data regarding the patients' return to soccer, surgical complications, and secondary surgical procedures were collected.

RESULTS

A total of 41 patients were eligible for inclusion in our study, of whom 34 (82.9%) had a mean follow-up period of 47.4 months. Five patients were not eligible because they did not intend to return to soccer. There were 15 male hips (44.1%) and 19 female hips (55.9%). The mean age at surgery was 20.8 ± 7.4 years. All PROs and the visual analog scale score improved significantly from preoperatively to latest follow-up. Of the 34 patients, 27 (79.4%) returned to soccer. Of the patients who returned to soccer, 19 (70.4%) were competing at the same level or a higher level compared with their highest level within 1 year of surgery. Regardless of competitive level, 21 patients (77.8%) reported that their athletic ability was the same as or higher than it was within 1 year of surgery.

CONCLUSIONS

Hip arthroscopy was associated with significant improvements in PROs for amateur soccer players. There was a high level of return to soccer and a high proportion of patients whose competitive level was similar or improved. As such, hip arthroscopy is a good option for soccer players, in the absence of underlying osteoarthritis, presenting with hip pathology.

LEVEL OF EVIDENCE

Level IV, case series.

Young elite Alpine and Mogul skiers have a higher prevalence of cam morphology than non-athletes

PURPOSE

To investigate the prevalence of cam morphology in (1) a group of young elite Mogul and Alpine skiers compared with non-athletes and (2) between the sexes.

METHOD

The hip joints of 87 subjects [n = 61 young elite skiers (29 females and 32 males) and n = 26 non-athletes (17 females and 9 males)] were examined using MRI, for measurements of the presence of cam morphology (α-angle ≥ 55).

RESULTS

The skiers had a significantly higher prevalence of cam morphology compared with the non-athletes (49% vs 19%, p = 0.009). A significant difference (p < 0.001) was also found between females and males, where 22% of the females and 61% of the males had cam morphology. Among the skiers, there was also a significant difference (p < 0.001) between the sexes, where 28% of the females and 68% of the males had cam morphology. This difference between the sexes was not found in the non-athletic group. No significant differences were found between Mogul and Alpine skiers.

CONCLUSION

Young male elite skiers have a higher prevalence of cam morphology of the hips compared with non-athletes.

LEVEL OF EVIDENCE

II.

The clinical presentation, diagnosis and pathogenesis of symptomatic sports-related femoroacetabular impingement (SRFAI) in a consecutive series of 1021 athletic hips

AIM

To examine the pathogenesis and clinical presentation of sports-related femoroacetabular impingement (SRFAI) in a large consecutive series of symptomatic athletes.

METHODS

Between January 2009 and February 2017 prospectively collected data from competitive athletes within the Gaelic Athletic Association (GAA), and who subsequently underwent arthroscopic treatment for symptomatic FAI, were analysed. Data was collected using internationally validated health questionnaires (Harris Hip Score, UCLA, SF-36, WOMAC) and recognised clinical (ROM, symptom presentation, provocation tests) and radiological (AP pelvis, Dunn, False profile) indicators/measures of FAI.

RESULTS

A total of 1021 consecutive cases (mean 26.6 ± 6.2 years) were included. In every case, conservative treatment failed to resolve symptoms with athletes attending an average of 2.4 ± 1.1 health care professionals prior to referral. Symptoms developed gradually (78%) and consisted primarily of groin pain (76.1%) and hip stiffness (76.5%) following activity. An acetabular rim deformity (pincer) was present in all cases; a cam deformity in 72.1%. The prevalence and degree of cam deformity increased with progressing age groups (p < 0.001); mean lateral centre-edge angle remained static (p = 0.456). Increasing CEA, alpha angle and presence of rim fracture was associated with a reduction in all ranges of hip movement (p < 0.001).

CONCLUSION

Symptomatic SRFAI presented in this large series of GAA athletes failed to resolve with non-operative treatment. Increasing hip deformity resulted in poorer ROM. Abnormal acetabular morphology remains static with increasing athletic age while cam deformity is progressive and most likely a secondary pathology.

Professional soccer is associated with radiographic cam and pincer hip morphology

PURPOSE

Femoroacetabular impingement (FAI) syndrome is characterized by a triad: symptoms, clinical signs and imaging findings. Some individuals, especially athletes, have only imaging alterations. The objective of this study was to evaluate the prevalence of cam and pincer morphology in professional soccer players compared with a control group of non-athletes and to investigate the association between the age at which players start playing competitive soccer more than three times per week and duration of the soccer career with the prevalence of these radiographic findings.

METHODS

The prevalence of cam and pincer morphology in sixty professional adult male soccer players and thirty-two male controls was determined using pelvic anteroposterior radiography. Data were recorded for all hips and correlated with the age at which the players started competitive soccer practice and with the duration of their soccer career.

RESULTS

The prevalence of morphological FAI in the soccer players was 92.5% versus 28.1% in the controls (p < 0.001). The duration of the soccer career was positively correlated with the alpha angle (p = 0.033) and negatively correlated with the retroversion index (p = 0.009). The age at which competitive play began was inversely correlated with the alpha angle (p < 0.001).

CONCLUSION

The study showed a high prevalence of cam and pincer morphology in Brazilian professional soccer players compared with controls. The duration of the soccer career was associated with an increased alpha angle and a decreased retroversion index, and the age at which competitive soccer participation began was negatively associated with alpha angle values. Finally, this manuscript provides data about the association between greater exposure to soccer and cam and pincer morphological changes in the hip; specifically, cam morphology was more common in patients who began participating in sports at earlier ages. This information serves as an alert for coaches of youth teams to manage the training load in youth athletes.

LEVEL OF EVIDENCE

III.

Current trends in sport and exercise hip conditions: Intra-articular and extra-articular hip pain, with detailed focus on femoroacetabular impingement (FAI) syndrome

Musculoskeletal conditions, such as hip pain are leading causes of pain and disability. Hip pain is the second most common cause of lower limb musculoskeletal pain, and is commonly seen in active individuals. Hip and groin pain may have intra-articular and extra-articular causes. Femoroacetabular impingement (FAI) syndrome and the associated pathologies are common intra-articular causes of hip and groin pain in active individuals. There are also a number of extra-articular causes of pain, which include musculotendinous conditions, extra-articular impingements and the clinical entities of groin pain described in the Doha agreement. This chapter will describe these, with a detailed focus on FAI syndrome. Specifically, it addresses: 1. What is and what causes FAI syndrome; 2. How do I diagnose FAI syndrome; and 3. What is the evidence-based approach to managing FAI syndrome?

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

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.

Prevalence of femoroacetabular impingement and effect of training frequency on aetiology in paediatric football players

PURPOSE:

The aim of this study was to determine the prevalence of asymptomatic radiographic findings of femoroacetabular impingement (FAI) in paediatric football players in different age groups and to investigate aetiological factors.

METHODS:

Paediatric male athletes between 10 and 17 years of age from 8 soccer teams were recruited. In addition to an annual control check-up, anteroposterior pelvis and frog-leg radiographs as well as the curriculum vitae of the athletes, their injuries, and real-time complaints were recorded. The alpha angle, lateral centre-edge angle, Tönnis angle, and collodiaphyseal angle were measured and morphological abnormalities were noted.

RESULTS:

There were 214 male football players with a mean age of 13.4 ± 3.2 years included in the study. In the morphological analysis of hips, there was FAI in 30% of the athletes. In the analysis of FAI prevalence in 3 subgroups based on age (Group 1: 10-12 years [ n = 25], Group 2: 13-15 years [ n = 104], Group 3: 16-17 years [ n = 85]), there was 0% FAI in Group 1, 19.1% in Group 2 and 60% in Group 3. In the analysis of aetiological factors, there was no significant difference between the right and left hips of players regarding alpha angles and FAI prevalence. However, the prevalence of FAI was higher in players who had been playing football for 3 years or more and who had been training for 12.5 hours/week or more.

CONCLUSION:

Training for 12.5 hours or more per week in paediatric football players doubled the risk development of FAI morphology.

Prevalence of labrum and articular cartilage injuries of the hip on 3T magnetic resonance imaging of asymptomatic elite soccer players

OBJECTIVE

To establish the prevalence of lesions of the labrum and articular cartilage of the hip in asymptomatic elite soccer players by performing 3T magnetic resonance imaging.

METHODS

Eighty-four asymptomatic hips of 42 professional soccer players were evaluated. Male subjects older than 18 years were included. Cam and pincer deformity were defined as an alpha angle greater than 55 degrees and a lateral centre edge angle greater than 39 degrees, respectively. Labral injuries were classified with the Czerny classification and cartilage damage was classified with the Outerbridge classification. Specific statistical tests were used to establish the relationship between anatomical variances of the hip and the presence of chondral and labral injuries.

RESULTS

FAI morphology prevalence was 25%. Abnormalities such as cam (22.5%) and labral injuries (33.8%) were found. Those cases with reported labral injury were predominantly intrasubstance damage (18.8%). Anatomical features of FAI were found to be related to lesions of the femoral cartilage (P<.001), chondrolabral damage (P=.042), or both injuries (P<.001).

CONCLUSION

Asymptomatic labral or cartilaginous injuries of the hip were reported in 25% of the included professional soccer players. These injuries were associated with anatomical features of FAI.

Hip Joint Torsional Loading Before and After Cam Femoroacetabular Impingement Surgery

BACKGROUND

Surgical management of cam femoroacetabular impingement (FAI) aims to preserve the native hip and restore joint function, although it is unclear how the capsulotomy, cam deformity, and capsular repair influence joint mechanics to balance functional mobility.

PURPOSE

To examine the contributions of the capsule and cam deformity to hip joint mechanics. Using in vitro, cadaveric methods, we examined the individual effects of the surgical capsulotomy, cam resection, and capsular repair on passive range of motion and resistance of applied torque.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Twelve cadaveric hips with cam deformities were skeletonized to the capsule and mounted onto a robotic testing platform. The robot positioned each intact hip in multiple testing positions: (1) extension, (2) neutral 0°, (3) flexion 30°, (4) flexion 90°, (5) flexion-adduction and internal rotation (FADIR), and (6) flexion-abduction and external rotation. Then the robot performed applicable internal and external rotations, recording the neutral path of motion until a 5-N·m of torque was reached in each rotational direction. Each hip then underwent a series of surgical stages (T-capsulotomy, cam resection, capsular repair) and was retested to reach 5 N·m of internal and external torque again after each stage. During the capsulotomy and cam resection stages, the initial intact hip's recorded path of motion was replayed to measure changes in resisted torque.

RESULTS

Regarding changes in motion, external rotation increased substantially after capsulotomies, but internal rotation only further increased at flexion 90° (change +32%, P = .001, d = 0.58) and FADIR (change +33%, P < .001, d = 0.51) after cam resections. Capsular repair provided marginal restraint for internal rotation but restrained the external rotation compared with the capsulotomy stage. Regarding changes in torque, both internal and external torque resistance decreased after capsulotomy. Compared with the capsulotomy stage, cam resection further reduced internal torque resistance during flexion 90° (change -45%, P < .001, d = 0.98) and FADIR (change -37%, P = .003, d = 1.0), where the cam deformity accounted for 21% of the intact hip's torsional resistance in flexion 90° and 27% in FADIR.

CONCLUSION

Although the capsule played a predominant role in joint constraint, the cam deformity provided 21% to 27% of the intact hip's resistance to torsional load in flexion and internal rotation. Resecting the cam deformity would remove this loading on the chondrolabral junction.

CLINICAL RELEVANCE

These findings are the first to quantify the contribution of the cam deformity to resisting hip joint torsional loads and thus quantify the reduced loading on the chondrolabral complex that can be achieved after cam resection.

Adolescent elite skiers with and without cam morphology did change their hip joint range of motion with 2 years follow-up

PURPOSE

To investigate how range of motion of the hips and the lumbar spine are affected by continued elite, alpine skiing in young subjects, with and without a magnetic resonance imaging verified cam morphology, in a 2-year follow-up study. The hypothesis is that skiers with cam morphology will show a decrease in hip joint range of motion as compared with skiers without cam, after a 2-year follow-up.

METHOD

Thirty adolescent elite alpine skiers were examined at the baseline (mean age 17.3 ± 0.7 years) and after 2 years. All skiers were examined for the presence of cam morphology (α-angle > 55°) using magnetic resonance imaging at the baseline. Clinical examinations of range of motion in standing lumbar flexion and extension, supine hip flexion, internal rotation, FABER test and sitting internal rotation and external rotation were performed both at the baseline and after 2 years.

RESULTS

Skiers with and without cam morphology showed a significant decrease from baseline to follow-up in both hips for supine internal rotation (right: mean - 13.3° and - 10.9° [P < 0.001]; left: mean - 7.6° [P = 0.004] and - 7.9° [P = 0.02]), sitting internal rotation (right: mean - 9.6° and - 6.3° [P < 0.001]; left: mean - 7.6° [P = 0.02] and - 3.3° [P = 0.008]) and sitting external rotation (right: mean - 16.9° and - 11.4° and left: mean - 17.9° and - 14.5° [P < 0.001]) and were shown to have an increased left hip flexion (mean + 8.4° and + 4.6° [P = 0.004]). Skiers with cam were also shown to have an increased right hip flexion (mean + 6.4° [P = 0.037]). Differences were found between cam and no-cam skiers from baseline to follow-up in the sitting internal rotation in both hips (right: mean 3.25°, left: mean 4.27° [P < 0.001]), the right hip flexion (mean 6.02° [P = 0.045]) and lumbar flexion (mean - 1.21°, [P = 0.009]).

CONCLUSION

Young, elite alpine skiers with cam morphology decreased their internal rotation in sitting position as compared with skiers without the cam morphology after 2 years of continued elite skiing.

LEVEL OF EVIDENCE

II.

Reactive Osteochondromatous Lesion of the Femoral Neck in a Highly Active Preadolescent Patient: Is This the Pathogenesis of a Cam Deformity?

Here, we present a rare case of a preadolescent boy with a prominent bony bump on the femoral neck. The main histological feature was concordant with a reactive osteochondromatous lesion possibly induced by repetitive microtrauma, probably because of overtraining as a soccer goalkeeper. The nature of this pathological change is consistent with the growth of a cam deformity. Especially in the preadolescent age group, we should note that repetitive use of the same joint kinematics may induce a prominent cam deformity.

Cam morphology in young male football players mostly develops before proximal femoral growth plate closure: a prospective study with 5-yearfollow-up

OBJECTIVES

Cam morphology is not completely understood. The aim of this study was threefold: (1) to investigate if cam morphology development is associated with growth plate status; (2) to examine whether cam morphology continues to develop after growth plate closure; and (3) to qualitatively describe cam morphology development over 5-year follow-up.

METHODS

Academy male football players (n=49) participated in this prospective 5-year follow-up study (baseline 12-19 years old). Anteroposterior and frog-leg lateral views were obtained at baseline (142 hips), 2.5-year (126 hips) and 5-year follow-up (98 hips). Cam morphology on these time points was defined as: (A) visual scores of the anterior head-neck junction, classified as: (1) normal, (2) flattening, and (3) prominence; and (B) alpha angle ≥60°. Proximal femoral growth plates were classified as open or closed. Cam morphology development was defined as every increase in visual score and/or increase in alpha angle from <60° to ≥60°, between two time points. This resulted in 224 measurements for cam morphology development analysis.

RESULTS

Cam morphology development was significantly associated with open growth plates based on visual score (OR: 10.03, 95% CI 3.49 to 28.84, p<0.001) and alpha angle (OR: 2.85, 95% CI 1.18 to 6.88, p=0.020). With both definitions combined, cam developed in 104 of 142 hips during follow-up. Of these 104 hips, cam developed in 86 hips (82.7%) with open growth plate and in 18 hips (17.3%) with a closed growth plate. Cam morphology developed from 12 to 13 years of age until growth plate closure around 18 years.

CONCLUSION

Cam morphology of the hip is more likely to develop with an open growth plate.

Assessment of cam morphology of the hip with ultra sound imaging by physical therapists is reliable and valid

BACKGROUND

Femoroacetabular impingement syndrome is considered present when a combination of clinical symptoms, signs and morphological features of the hip co-exist. Imaging is increasingly popular in primary health care settings with physical therapists performing ultrasound (US).

OBJECTIVE

The aim of this study was to assess the diagnostic accuracy and inter-rater reliability of ultrasound in determining presence of cam morphology.

DESIGN

A concurrent validity and inter-rater reliability study.

METHODS

The presence of cam morphology of the hip was determined by α angle measures using Kinovea software. A cam was defined present when the α angle >60°. The index test was US and radiographs served as a gold standard.

RESULTS

Correlation between the radiographic α angle and ultrasound measures was r = 0.82 (p < 0.01). Inter-rater reliability was high with an ICC of 0.74 (95% CI 0.61-0.84). The predictive value for presence of cam morphology had a sensitivity of 79% and a specificity of 94%. The positive predictive value was 79% whereas the negative predictive value was 94%. Total accuracy was 90%.

CONCLUSIONS

Ultrasound conducted by trained physical therapists is a valid, reliable, specific and sensitive diagnostic tool to assess the presence of cam morphology.

Musculoskeletal Screening Tests and Bony Hip Morphology Cannot Identify Male Professional Soccer Players at Risk of Groin Injuries: A 2-Year Prospective Cohort Study

BACKGROUND

Musculoskeletal hip/groin screening tests are commonly performed to detect at-risk individuals. Bony hip morphology is considered a potential intrinsic risk factor but has not been examined prospectively.

PURPOSE

To evaluate the association between intrinsic risk factors identified from musculoskeletal and radiographic screening tests and hip/groin injuries leading to time loss from training and/or match play in professional male soccer players.

STUDY DESIGN

Prospective cohort study; Level of evidence, 2.

METHODS

Male professional soccer players, aged ≥18 years, underwent screening specific for hip/groin pain during 2 consecutive seasons of the Qatar Stars League. The screening battery included pain provocation, range of motion, and strength tests as well as a hip radiographic examination. The radiographic examination included an anteroposterior pelvic view and 45° Dunn view, with bony hip morphology determined using quantitative methods. Time-loss (≥1 day) hip/groin injuries and individual player exposure (training and match play) were recorded prospectively, and injuries were categorized as adductor-related, inguinal-related, iliopsoas-related, pubic-related, or hip-related groin pain, or "other," as recommended in the Doha agreement. We calculated hazard ratios (HRs) from univariate and multivariate Cox regression models to assess the relationship between potential risk factors and hip/groin injuries.

RESULTS

There were 438 players, completing 609 player seasons, and 113 hip/groin injuries that met the criteria for inclusion, with 85 injuries categorized as adductor-related. The proportion of players with bony morphological variants was the following: cam, 71%; pincer, 5%; and acetabular dysplasia, 13%. Previous hip/groin injuries (HR, 1.8; 95% CI, 1.2-2.7) and eccentric adduction strength were associated with the risk of hip/groin injuries. Higher (>1 SD above the mean) than normal eccentric adduction strength was associated with an increased risk for all hip/groin injuries (HR, 1.6; 95% CI, 1.0-2.5). Lower (<1 SD below the mean) than normal eccentric adduction strength was associated with an increased risk for adductor-related injuries (HR, 1.7; 95% CI, 1.0-3.0). No other musculoskeletal screening test or bony hip morphology variables were associated with the injury risk.

CONCLUSION

Previous groin injuries and eccentric adduction strength were associated with the risk of groin injuries. However, these associations were not strong enough to identify an "at-risk" individual, and therefore, musculoskeletal screening tests were not useful to dictate individualized prevention strategies. Bony hip morphology was not associated with the risk of groin injuries.

The Prevalence of Cam and Pincer Morphology and Its Association With Development of Hip Osteoarthritis

Synopsis Our understanding of femoroacetabular impingement syndrome is slowly improving. The number of studies on all aspects (etiology, prevalence, pathophysiology, natural history, treatment, and preventive measures) of femoroacetabular impingement syndrome has grown exponentially over the past few years. This commentary provides the latest updates on the prevalence of cam and pincer hip morphology and its relationship with development of hip osteoarthritis (OA). Cam and pincer morphology is highly prevalent in the general population and in this paper is presented for different subgroups based on age, sex, ethnicity, and athletic activity. Methodological issues in determining prevalence of abnormal hip morphology are also discussed. Cam morphology has been associated with development of hip OA, but the association between pincer morphology and hip OA is much less clear. Results from reviewed studies, as well as remaining gaps in literature on this topic, are critically discussed and put into perspective for the clinician. J Orthop Sports Phys Ther 2018;48(4):230-238. doi:10.2519/jospt.2018.7816.

Is Bony Hip Morphology Associated With Range of Motion and Strength in Asymptomatic Male Soccer Players?

Study Design Cross-sectional cohort study. Objectives To investigate the relationship between musculoskeletal screening findings and bony hip morphology in asymptomatic male soccer players. Background Athletes with femoroacetabular impingement (FAI) syndrome have cam and/or pincer morphology, pain on orthopaedic testing, and often reduced hip range of motion (ROM) and strength. However, cam and pincer morphology is also common in asymptomatic hips. Therefore, it is currently unknown whether the ROM and strength deficits observed in athletes with FAI syndrome result from the variance in their bony hip morphology or from their hip condition. Methods Male professional soccer players in Qatar were screened specifically for hip/groin pain in 2 consecutive seasons. The screening battery included pain provocation, ROM and strength tests, and hip radiographs. Univariate and multivariate regression analyses, using generalized estimating equations, evaluated the relationship between musculoskeletal screening findings and each bony hip morphological variant (cam, large cam, pincer, and acetabular dysplasia). Results Asymptomatic hips with cam and large cam morphology were associated with lower internal rotation ROM and bent-knee fall-out, and with a higher likelihood of pain on provocation testing. Pincer morphology was associated with lower abduction ROM and higher abduction strength. Acetabular dysplasia was associated with higher abduction ROM. Each association was weak and demonstrated poor or failed discriminatory power. Conclusion Bony hip morphology is associated with hip joint ROM and abduction strength, but musculoskeletal screening tests have a poor ability to discriminate between the different morphologies. J Orthop Sports Phys Ther 2018;48(4):250-259. doi:10.2519/jospt.2018.7848.

Influence of evolution on cam deformity and its impact on biomechanics of the human hip joint

Anatomy and biomechanics of the human hip joint are a consequence of the evolution of permanent bipedal gait. Habitat and behaviour have an impact on hip morphology and significant differences are present even within the same biological family. The forces acting upon the hip joint are mainly a function of gravitation and strength of the muscles. Acetabular and femoral anatomy ensure an inherently stable hip with a wide range of motion. The femoral head in first human ancestors with upright gait was spherical (coxa rotunda). Coxa rotunda is also seen in close human relatives (great apes) and remains the predominant anatomy of present-day humans. High impact sport during adolescence with open physis however can activate an underlying genetic predisposition for reinforcement of the femoral neck, causing an epiphyseal extension and the formation of an osseous asphericity at the antero-superior femoral neck (cam deformity). The morphology of cam deformity is similar to the aspherical hips of quadrupeds (coxa recta), with the difference that in quadrupeds the asphericity is posterior. It has been postulated that this is due to the fact that humans bear weight on the extended leg, while quadrupeds bear weight at 90-100° flexion. The asphericity alters the biomechanical properties of the joint and as it is forced into the acetabulum leading to secondary cartilage damage. It is considered a risk factor for later development of osteoarthritis of the hip. Clinically this presents as reduced range of motion, which can be an indicator for the structural deformity of the hip. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 9999:XX-XX, 2018.