Radiographic Hip Anatomy Correlates With Range of Motion and Symptoms in National Hockey League Players

Establishing a Reference Database for Select Clinical Measures in National Basketball Association Players

BACKGROUND

Musculoskeletal injuries are prevalent in the NBA and are associated with a significant number of games missed. There is a lack of reference data for clinical measures in NBA players, making it difficult for sports medicine professionals to set goals and develop programs.

HYPOTHESIS

Values for clinical measures in NBA players will differ from those of the general population but will not differ between dominant (D) and nondominant (ND) limbs.

STUDY DESIGN

Descriptive laboratory study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Clinical measures were taken on 325 players invited to NBA training camp (2008-2022). Measures included range of motion for great toe extension, hip rotation, weightbearing ankle dorsiflexion, flexibility, arch height (AH) indices, and tibial varum.

RESULTS

Clinical values for NBA players differ from reference norms of the general population. Results for NBA players include great toe extension (D, 40.4°; ND, 39.3°), 90/90 hamstring (D, 41.5°; ND, 40.9°), hip internal rotation (D, 29.0°; ND, 28.8°), hip external rotation (D, 29.7°; ND, 30.9°), total hip rotation (D, 60.2°; ND, 60.4°), Ely (D, 109.9°; ND, 108.8°), AH difference (D, 0.5 mm; ND, 0.5 mm), AH index (D, 0.310; ND, 0.307), arch stiffness (D, 0.024; ND, 0.024), arch rigidity (D, 0.924; ND, 0.925), tibial varum (D, 4.6°; ND, 4.5°), and weightbearing ankle dorsiflexion (D, 35.4°; ND, 35.6°). Descriptive statistics are presented; 2-tailed paired t tests show that, whereas most measures demonstrated differences between sides, the results were not statistically significant.

CONCLUSION

Clinical measures of NBA players differ from those reported for the general population and athletes of other sports although there were no statistically significant differences between D and ND limbs.

CLINICAL RELEVANCE

Establishing a reference database may help clinicians develop more sensitive and more effective preseason and return-to-play screening processes, aiding the management of player orthopaedic care and reducing injury risk.

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.

Preseason lower extremity range of motion, flexibility, and strength in relation to in-season injuries in NCAA division I gymnasts

OBJECTIVES

To determine if preseason lower extremity ROM, flexibility, and strength differ in collegiate gymnasts (NCAA Division 1) who do or do not sustain an injury during the competitive season.

METHODS

Over four seasons, a total of 15 female gymnasts (age = 20.5 ± 1.0 years) underwent preseason screening (30 gymnast-season). We tested joint ROM (hip: flexion, internal and external rotation; ankle: weightbearing dorsiflexion), muscle flexibility (passive straight leg raise, Thomas,' Ober's, Ely's tests) and strength (hip extensors, abductors, and flexors isometric strength via a handheld dynamometer; knee: quadriceps and hamstring isokinetic strength at 60°/sec). The team athletic trainer tracked overuse lower extremity injuries (restricted gymnasts from full participation, occurred as from participation in organized practice or competition, and required medical attention) during each season. For athletes that tested multiple seasons, each encounter was considered independent, and each preseason assessment was linked to overuse injuries sustained during the same competitive season. Gymnasts were dichotomized into injured and non-injured groups. An independent t-test was used to measure differences in preseason outcomes between injured and non-injured groups.

RESULTS

During four years, we recorded 23 overuse lower extremity injuries. Gymnasts that sustained an in-season overuse injury demonstrated significantly lower hip flexion ROM (mean difference: -10.6°; 95% confidence interval: -16.5, -4.6; p < 0.01) and lower hip abduction strength (mean difference: -4.7% of body weight; 95% confidence interval: -9.2, -0.3; p = 0.04).

CONCLUSION

Gymnasts who sustain an in-season overuse lower extremity injury have significant preseason deficit of hip flexion ROM and weakness in the hip abductors. These findings indicate potential impairments in the kinematic & kinetic chains responsible for skill performance and energy absorption during landing.

Femoroacetabular Impingement in Ice Hockey Athletes

ABSTRACT

Femoroacetabular impingement (FAI) in ice hockey is a concern for many athletes. The biomechanics of skating and the injury mechanism, prevalence, identification, and treatment protocols currently available for FAI in ice hockey athletes are important for all coaches and practitioners to understand. This article discusses the underlying anatomical issues and biomechanical considerations surrounding FAI. Furthermore, this article describes the interventions that can be used when encountering FAI and well-established protocols to aid in the return to play. Finally, prevention strategies that can aid in injury prevention are discussed.

Risk Factors for Athletic Pubalgia in Collegiate Football Student-Athletes: A Retrospective Cohort Study

BACKGROUND

Athletic pubalgia (AP) is an increasingly recognized injury among young athletes. This study aimed to evaluate the characteristics associated with AP in college football players.

HYPOTHESIS

Repetitive explosive movements that require aggressive core muscle activation results in AP in collegiate football players.

STUDY DESIGN

Retrospective cohort design.

LEVEL OF EVIDENCE

Level 3.

METHODS

Football student-athletes at a single Division I collegiate institution from January 2010 to December 2019 were included in the study. The primary outcome measure was surgery for AP. The odds of AP were determined using logistic regression, with the dependent variable being whether or not the student-athlete received AP surgery. Independent variables included Olympic weightlifting (OWL) exposure, primary playing position (skill position vs nonskill position), and body mass index (BMI).

RESULTS

A total of 1154 total student-athlete exposures met the inclusion criteria. Of the 576 student-athletes exposed to OWL (OWL occurred throughout entire calendar year), 20 developed AP, whereas 7 student-athletes not exposed to OWL (OWL was not performed at any point during calendar year) developed AP. Student-athletes exposed to OWL had a 2.86 (95% CI, 1.25-7.35; P = 0.02) times higher odds of AP than players not exposed after controlling for primary playing position and BMI. Skill position players had a 9.32 (95% CI, 1.71-63.96; P = 0.01) times higher odds of AP than nonskill position players when controlling for BMI and OWL training.

CONCLUSION

Modifiable factors that increase exposure to repetitive explosive activities, such as OWL and playing a skill position, may be important considerations in developing AP.

CLINICAL RELEVANCE

The cause of AP is multifactorial and poorly understood. Identifying factors associated with AP informs athletes, athletic trainers, physicians, and coaches.

Hip Strength Profiling of Ice Hockey Athletes Across Various Joint-Specific Angles: Monitoring and Injury Implications

ABSTRACT

Secomb, JL, Kelly, M, and Dascombe, BJ. Hip strength profiling of ice hockey athletes across various joint-specific angles: monitoring and injury implications. J Strength Cond Res 37(7): e422-e429, 2023-The purpose of this research was to compare the hip adduction and abduction relative strength, adduction-to-abduction strength ratio (ADD:ABD), and interlimb asymmetries of ice hockey athletes between the typically used bilateral position and 3 unilateral positions in joint-specific angles (0°, 25°, and 50° of hip abduction) relevant to an ice hockey stride. A secondary purpose was to explore any relationships between these measures and hip and groin noncontact injuries, and self-reported pain and disability. Twenty-five semiprofessional male ice hockey athletes (26.7 ± 6.7 years) were assessed for hip abduction range of motion (ROM), hip adduction and abduction relative strength, and completed the Copenhagen Hip and Groin Outcome Score (HAGOS) questionnaire. Within-subjects repeated-measures analysis of variance revealed a significant effect for the assessment position for adduction ( F1,24 = 52.4, p < 0.01) and abduction relative strength ( F1,24 = 152.1, p < 0.01), ADD:ABD ( F1,24 = 38.9, p < 0.01), and the interlimb asymmetries for each of these variables ( F1,24 = 9.8-12.3; p < 0.01), with large strength differences observed between the bilateral assessment and all unilateral assessment positions for adduction and abduction relative strength. In addition, 4 athletes experienced a noncontact hip or groin injury within 1 month after testing, and when compared with the rest of the cohort ( n = 21) with Welch's t -tests, demonstrated significantly reduced hip abduction ROM (mean difference [MD] = -8.4 ± 2.5°; p < 0.01), sport subscale score for the HAGOS questionnaire (MD = -33.9 ± 7.1; p < 0.01), and a decline in hip adduction relative strength in the unilateral position of 50° compared with the position of 25° hip abduction (MD = -13.4 ± 3.8; p = 0.04). These results suggest that practitioners working with ice hockey athletes may benefit from profiling hip strength in these unilateral joint-specific angle positions because they provide an evidence base to determine the hip strength needs of ice hockey athletes in positions associated with skating performance and noncontact hip and groin injury mechanisms (between 25° and 50° of hip abduction).

Osteoarthritis Risks and Sports: An Evidence-based Systematic Review

PURPOSE

Regular sports activities are associated with multiple physical and psychological health benefits. However, sports also may lead to injuries and the development of osteoarthritis (OA). This systematic review investigated the association between sports activity, sports type, and the risk of developing OA.

METHODS

A systematic review was performed by assessing studies that have investigated the risk of OA development in sports. Data extracted included general information, study design, number of participants, related body mass index, sports type, and assessment of OA. The methodological quality of the studies was assessed using the Newcastle-Ottawa Scale.

RESULTS

A total of 63 studies were included in this systematic review. The overall Newcastle-Ottawa Scale score was 6.46±1.44 demonstrating a good methodological quality of the articles included in the present study. A total of 628,036 participants were included, with a mean follow-up of 8.0±8.4 years. The mean age of the included athletes was 45.6±15.8, with a mean body mass index of 24.9±2.3 kg/m 2 .

CONCLUSION

Football and soccer players seem to be at higher risk for the development of OA, although the injury status of the joint should be considered when assessing the risk of OA. High equipment weight and increased injury risk also put military personnel at a higher risk of OA, although elite dancing leads to more hip labral tears. Femoroacetabular impingement was also often diagnosed in ice-hockey players and ballet dancers.

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).

A Scoping Review of Injuries in Amateur and Professional Men’s Ice Hockey

Background:

Orthopaedic injuries are common in ice hockey at all levels and can result in physical and psychological adverse effects on these athletes.

Purpose:

Primarily, to summarize published data on orthopaedic hockey injuries at the junior through professional level. Secondarily, to characterize the literature based on anatomic site injured, return-to-play rates, cause/mechanism of injury, time lost, and treatments used.

Study Design:

Scoping review; Level of evidence, 4.

Methods:

PubMed, EMBASE, Cochrane library, and SCOPUS were searched using the terms “hockey” and “injuries” using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, and 4163 studies involving orthopaedic injuries were identified. Our inclusion criteria consisted of accessible full-text articles that evaluated orthopaedic injuries in men’s ice hockey athletes of all levels. We excluded case reports and articles evaluating women’s ice hockey injuries, as well as those evaluating nonorthopaedic injuries, such as concussions; traumatic brain injuries; and facial, dental, and vascular injuries, among others. Studies were divided based on level of play and anatomic site of injury. Level of evidence, year published, country of corresponding author, method of data collection, incidence of injury per athlete-exposure, and time lost were extracted from each article.

Results:

A total of 92 articles met the inclusion criteria and were performed between 1975 and 2020, with the majority published between 2015 and 2020. These were divided into 8 anatomic sites: nonanatomic-specific (37%), intra-articular hip (20.7%), shoulder (9.8%), knee (8.7%), trunk/pelvis (7.6%), spine (7.6%), foot/ankle (6.5%), and hand/wrist (2.2%). Of these studies, 71% were level 4 evidence. Data were obtained mostly via surveillance programs and searches of publicly available information (eg, injury reports, player profiles, and press releases).

Conclusion:

This scoping review provides men’s hockey players and physicians taking care of elite ice hockey athletes of all levels with a single source of the most current literature regarding orthopaedic injuries. Most research focused on nonanatomic-specific injuries, intra-articular hip injuries, knee injuries, and shoulder injuries, with the majority having level 4 evidence.

Imaging Review of Hockey-related Lower Extremity Injuries

Hockey is a fast-paced contact sport with a high incidence of injuries. Although injuries are more frequent among elite players, recreational hockey injuries are a common issue faced by primary care and emergency physicians. Lower extremity injuries in hockey are particularly important because they account for approximately a third of all injuries and > 60% of all overuse injuries. This pictorial review provides the general and specialty trained radiologist with a knowledge of the patterns of lower extremity injury that occur in ice hockey.

Prevalence of Borderline Acetabular Dysplasia in Symptomatic and Asymptomatic Populations: A Systematic Review and Meta-analysis

Background:

Patients with borderline acetabular dysplasia are a controversial patient population in hip preservation, as some have primarily impingement-based symptoms and others have instability-based symptoms. Borderline dysplasia is most commonly defined as a lateral center-edge angle (LCEA) of 20° to 25°. However, its prevalence has not been well established in the literature.

Purpose:

To (1) define the prevalence of borderline hip dysplasia in the general population as well as in populations presenting with hip pain using a systematic review and meta-analysis of the literature and (2) describe differences between male and female patients as well as differences in prevalence from that of classic acetabular dysplasia.

Study Design:

Systematic review; Level of evidence, 3.

Methods:

A systematic review of the literature was performed using search terms to capture borderline dysplasia, or studies reporting prevalence by LCEA. The search yielded 1932 results, of which 11 articles met inclusion criteria and were included in the final systematic review. Studies were grouped by patient cohort as (1) asymptomatic general population, (2) asymptomatic targeted population (eg, athletes in a specific sport), and (3) symptomatic hip pain population. The reporting of prevalence rates by subject or by hip was recorded. In a study, the rates of borderline dysplasia were compared with those of classic acetabular dysplasia (LCEA, <20°).

Results:

The 11 studies included 19,648 hips (11,754 patients). In the asymptomatic general population, the pooled estimate of the prevalence of borderline dysplasia was 19.8% by subject and 23.3% by hip (range, 16.7%-46.0%). The targeted subpopulation group included 236 athletes with subgroups in ballet, football, hockey, volleyball, soccer, and track and field with prevalence ranging from 17.8% to 51.1%. The prevalence of borderline dysplasia in groups presenting with hip pain was 12.8% (range, 12.6%-16.0%). Borderline acetabular dysplasia was 3.5 times more common than classic acetabular dysplasia in the asymptomatic general population.

Conclusion:

This study demonstrated a prevalence of borderline dysplasia of 19.8% to 23.3% in the asymptomatic general population. Additionally, an estimated prevalence of 12.8% of hips in symptomatic patients highlights the common decision-making challenges in this population.

Nonsurgical Versus Surgical Management of Femoroacetabular Impingement: What Does the Current Best Evidence Tell Us

Controversy exists as to the management of femoroacetabular impingement (FAI). When nonsurgical management of symptomatic FAI fails, surgical management is generally indicated. However, many groups with a stake in patient care (particularly payors) have insisted on higher levels of evidence. Recently, there have been several Level I studies published, comparing physical therapy (PT) with hip arthroscopy in the management of symptomatic FAI. All of these studies have used outcomes tools developed and validated for patients with nonarthritic hip pain (the International Hip Outcome Tool). Most highest level evidence confirms that although patients with FAI do benefit from PT, patients who undergo surgical management for FAI with hip arthroscopy benefit more than those who undergo PT (mean difference in the International Hip Outcome Tool 6.8 [minimal clinically important difference 6.1], P = 0.0093). Future large prospective studies are needed to evaluate the effect on the outcomes when there is a delay in surgical management in symptomatic individuals, assess whether FAI surgery prevents or delays osteoarthritis, and determine the role of other advanced surgical techniques.

Characterizing cam-type hip impingement in professional women's ice hockey players

OBJECTIVE

There is a high prevalence of femoroacetabular impingement (FAI) amongst elite men's ice hockey players, yet little is known about the hips of players in the National Women's Hockey League (NWHL). The primary purpose of this study was to determine the prevalence of radiographic cam-type FAI in women's professional ice hockey players. The secondary purpose was to analyze the relationship between the cam deformity and both menarchal age and hip range-of-motion (ROM).

METHODS

Data were collected for NWHL players during pre-participation physicals. Alpha angles were measured on 45° Dunn radiographs, with alpha angles >55° defined as cam-positive. Pearson correlation coefficients (ρ) were performed to analyze the relationship between alpha angle and both ROM measurements and menarchal age, with statistical significance set at p < 0.05.

RESULTS

Twenty-six athletes were included. Twenty-four (92%) had alpha angles >55°; 20 players (77%) had bilateral cam deformity. Average menarchal age was 13.8 ± 1.7 years. There was a significant association between age of menarche and alpha angle (ρ = 0.36, p < 0.02). There was no significant association between alpha angle and hip ROM (p > 0.05).

CONCLUSION

Elite women's ice hockey players have a higher prevalence of cam-type morphology than the general population. The positive association between alpha angle and menarchal age lends additional support to the etiological hypothesis of the cam lesion resulting from activity-related stress at the proximal femoral physis during skeletal development. Professional women's ice hockey players have a high risk of developing cam-type morphology, although each player's menarchal age may mediate her individual risk for cam development.

Acetabular Rim Disorders/Pincer-type Femoroacetabular Impingement and Hip Arthroscopy

Femoroacetabular impingement (FAI) can lead to acetabular impaction, chondral injury, and labral pathology secondary to deformities of the proximal femur (CAM-type FAI), acetabulum (pincer-type FAI), or with combined FAI. While the majority of cases are of the combined type, this paper focuses on acetabular overcoverage/pincer-type deformities. Various pincer subtypes include focal anterior overcoverage, global retroversion, global overcoverage/profunda, protrusio, subspine impingement, and os acetabuli/rim fracture variants. A thorough history and physical examination, plain radiographs, magnetic resonance imaging, 3-dimensional computerized tomography, and diagnostic injections can lead to an accurate assessment of pincer-type variants. Appropriately indicated arthroscopic management techniques and pearls for the various pincer subtypes can lead to improved patient-related outcome measures and a high rate of return to athletic activity for the majority of these patients.

Morphological Changes of the Hip Commonly Associated With Femoroacetabular Impingement Are Not Correlated With Rotational Range of Hip Motion in Elite Soccer Athletes

BACKGROUND

Morphological changes characteristic of femoroacetabular impingement (FAI) are common in soccer players. However, the clinical relevance of such anatomical variations is still not well-defined.

HYPOTHESIS

We hypothesized that high alpha angle values and/or acetabular retroversion index (ARI) are correlated with rotational range of motion (ROM) of the hip and that there are clinical-radiological diferences between the dominant lower limb (DLL) and nondominant lower limb (NDLL) in professional soccer players.

STUDY DESIGN

Cross-sectional.

LEVEL OF EVIDENCE

Level 3.

METHODS

A total of 59 male professional soccer players (average age 25.5 years, range 18-38 years) were evaluated in the preseason. As main outcome measures, we evaluated the alpha angle and the ARI and hip IR and ER ROM with radiographic analysis.

RESULTS

The measurements taken on DLL and NDLL were compared and a significant difference was found between the sides in the ER (P = 0.027), where the DLL measures were 1.54° (95% CI, 0.18-2.89) greater than the NDLL. There were no significant differences between the sides in the measures of IR (P > 0.99), total ROM (P = 0.07), alpha angle (P = 0.250), and ARI (P = 0.079). The correlations between the rotation measurements and the alpha angle in each limb were evaluated and the coefficient values showed no correlation; so also between the ARI and rotation measures.

CONCLUSION

Morphological changes of the femur or acetabulum are not correlated with hip IR and ER ROM in male professional soccer players. ER on the dominant side was greater than on the nondominant side. There was no significant difference in the other measurements between sides.

CLINICAL RELEVANCE

In clinical practice, it is common to attribute loss of hip rotational movement to the presence of FAI. This study shows that anatomical FAI may not have a very strong influence on available hip rotational movement in professional soccer athletes.

Editorial Commentary: Ultrasound-Guided Injection With Dynamic Assessment Could Improve Outcomes in Atypical and Revision Hip Arthroscopy Patients: But Today, Few Are Trained to Hear at Such High Frequencies

Imaging modalities for hip disorders all have their strengths and weaknesses. Magnetic resonance imaging is superior for evaluating soft tissue pathology, computerized tomography best characterizes osseous morphology, and plain radiographs can accurately depict 2-dimensional anatomy and are familiar to most clinicians. Ultrasound-guided injections have become commonplace in the musculoskeletal arena. Ultrasound evaluation of musculoskeletal anatomy has received increased attention, has the ability to image soft tissue and osseous structures, and more importantly, has the ability to dynamically evaluate these structures in real time. A noninvasive dynamic assessment of the hip region could be an absolute game changer for the hip preservation/sports medicine community in the diagnosis of atypical hip pain, femoroacetabular impingement, and labral tears. Widespread ability and expertise to perform these dynamic ultrasound assessments, however, is not in place at this time. We need more training and studies to best harness the potential benefits of these sound waves.

Less hip range of motion is associated with a greater alpha angle in people with longstanding hip and groin pain

PURPOSE

A higher alpha angle has been proposed to correlate with lower hip range of motion, but the association in people with longstanding hip and groin pain is currently unclear. The aims were to: (1) assess the association between range of motion and alpha angle in patients with longstanding hip and groin pain; (2) examine if a cut-off value in range of motion variables could identify patients with an alpha angle above or below 60°.

METHODS

Seventy-two participants were consecutively recruited from an orthopaedic department after referral for hip- and groin-related pain. Passive hip range of motion was measured in flexion, internal rotation with 90° hip flexion, internal rotation in neutral hip position, external rotation with 90° hip flexion, and abduction. The alpha angle was calculated from a frog-leg lateral radiograph. Linear regression examined the association between range of motion and alpha angle, and an ROC-curve analysis was performed to identify the sensitivity and specificity of range of motion cut-offs.

RESULTS

Lower range of motion in internal rotation in flexion, external rotation, and abduction were associated with higher alpha angle. Internal rotation of 27° or less displayed good sensitivity (81%) and specificity (85%) to detect an alpha angle above 60°, while a cut-off of 41° in external rotation and 27° in abduction showed a sensitivity of 72% and specificity of 50% and 60%, respectively.

CONCLUSION

Less internal rotation in flexion, external rotation, and abduction are associated with a greater alpha angle in a cohort of people with longstanding hip and groin pain. A cut-off of 27° in internal rotation has good sensitivity and specificity to identify people with an alpha angle above or below 60° and have the potential to be used in the clinical setting to identify patients that require further imaging, or that are unlikely to have cam morphology.

LEVEL OF EVIDENCE

II.

A Systematic Review of the Orthopedic Literature Involving National Hockey League Players

Background

Orthopedic injuries of National Hockey League (NHL) players are common and may significantly affect players’ health and careers. Evidence-based injury management is important in guiding players’ timely return to sport and their ability to play at their pre-injury levels of competition.

Purpose

To summarize all data published between January 1980 and March 2020 on orthopedic injuries experienced by professional ice hockey players competing in the NHL.

Study Design

Systematic review.

Methods

A literature review of studies examining orthopedic injuries in the NHL was performed using the Embase, PubMed, and CINAHL databases. The review included studies focusing on NHL players and players attending the NHL Combine and preseason NHL team camps. Studies pertaining to non-orthopedic injuries and case reports were excluded.

Results

A total of 39 articles met the inclusion criteria and were analyzed. The articles were divided by anatomic site of injury for further analysis: hip and pelvis (24%), general/other (14%), ankle (10%), knee (10%), foot (7%), shoulder (7%), thigh (7%), trunk (7%), spine (6%), elbow (4%), and hand and wrist (4%). The majority of articles were Level IV Evidence (51.3%), followed by Level III Evidence (38.5%). Most studies obtained data from publicly available internet resources (24.7%), player medical records (19.5%) or surveys of team physicians and athletic trainers (15.5%). A much smaller number of studies utilized the NHL Injury Surveillance System (NHLISS) (6.5%) or the Athlete Health Management System (AHMS) (2.6%).

Conclusion

This systematic review provides NHL team physicians with a single source of the current literature regarding orthopedic injuries in NHL players. Most research was published on hip and pelvis (24%) injuries, did not utilize the NHLISS and consisted of Level IV Evidence.

Rotation or flexion alters mechanical leg axis measurements comparably in patients with different coronal alignment

PURPOSE

Flexion and rotation of the knee joint are supposed to alter the measurement of the mechanical leg axis on long leg radiographs. However, in patients with varus or valgus alignment it has not been systematically analyzed so far. The hypothesis is that measurement of the mechanical leg axis is more influenced by flexion and rotation in presence of varus or valgus alignment compared to patients with a straight coronal alignment.

METHODS

3D surface models of the lower extremities of seven individuals with varying degrees of coronal alignment were created based on CT data. The coronal alignment of the seven individuals captured the range between 9° varus and 9° valgus with equal steps of 3°. Combinations of internal and external rotations of 10°, 20°, and 30° with flexion of 5°, 10°, 15°, 20°, and 30° were simulated. The mechanical leg axis was measured for each combination as the antero-posterior (ap)-projected hip-knee-ankle (HKA-) angle.

RESULTS

294 simulations with all combinations of rotation and flexion were performed. Ranges of deviation of HKA never showed a critical deviation of more than 3° from median values. Deviations from baseline appeared normally distributed for all flexion and rotation combinations (p < 0.05) and the probability for a deviation from the mean mechanical leg axis of more than 3° was less than 0.03 for all combinations. Comparability of the models, therefore, could be assumed.

CONCLUSION

Deviations in HKA-angle measurements, caused by rotation or flexion, does not vary relevantly through the range of coronal alignment of 9° varus to 9° valgus. As a clinical relevance, deviations in HKA-angle measurements can be considered as comparable in patients with different coronal alignment.

LEVEL OF EVIDENCE

III.

Reliability of hip range of motion measurement among experienced arthroscopic hip preservation surgeons

The aim of this study was to determine (i) the reliability of hip range of motion measurement among experienced arthroscopic hip preservation surgeons and (ii) the magnitude of hip flexion change with posterior pelvic tilt. Five experienced arthroscopic hip preservation surgeons (5–18 years of hip surgery experience) performed passive hip range of motion (internal and external rotation), flexion (contralateral hip extended) and flexion with posterior pelvic tilt (contralateral hip maximally flexed) on five young healthy asymptomatic volunteers (three males, two females; 34.4 ± 10.7 years of age). Motion was measured via digital photography and goniometry. Inter-observer reliability was calculated via two-way mixed, single measures, intra-class correlation coefficient. Paired t-test was utilized to compare hip flexion (with contralateral hip extended) to hip flexion with posterior pelvic tilt (with contralateral hip in forced flexion). The reliabilities of measurements of hip flexion with posterior pelvic tilt and external rotation were excellent, that of hip flexion was fair, and that of hip internal rotation was poor. The magnitude of hip flexion increase with posterior pelvic tilt was 17.0° ± 3.0° (P < 0.001). The reliability of hip range of motion measurement by five experienced arthroscopic hip preservation surgeons was excellent for measures of hip flexion with posterior pelvic tilt and external rotation. Contralateral maximal hip flexion significantly increased ipsilateral hip flexion (approximately 17°).

Level of Evidence: Diagnostic, level III (without consistently applied reference standard)

Predictors of Clinically Suspected Intra-articular Hip Symptoms and Prevalence of Hip Pathomorphologies Presenting to Sports Medicine and Hip Preservation Orthopaedic Surgeons

PURPOSE

The first purpose of the study was to evaluate the prevalence of various radiographic parameters and pathomorphologies for patients presenting with the diagnosis of hip pain. The second purpose of this study was to identify those pathomorphologies and radiographic parameters that were predictive of clinically suspected intra-articular and hip joint-related symptoms.

METHODS

A total of 998 hips (499 patients, 228 males, 271 females, mean age 38 years) presented to 2 orthopaedic surgeons with the diagnosis of hip pain. Patients were retrospectively identified as intra-articular and hip joint-related symptoms or extra-articular and non-hip joint-related symptoms based on history, examination, injection response, and diagnosis listed on clinical notes. A detailed morphologic evaluation of anteroposterior and 45° modified Dunn lateral radiographs of both hips was performed for all patients.

RESULTS

The presence of at least 1 finding consistent with femoroacetabular impingement (FAI) was noted in 96.6% of patients (89.9% of hips) and was bilateral in 83%. The prevalence of dysplasia was 10.6% in patients (6.7% of hips) and was bilateral in 2.8%. Cam-type morphology was more common in males (P < .001). Profunda and protrusio were more common in females (P < .001). Acetabular retroversion was more common in males (P = .02). Fifty-seven percent of hips (564/998) were diagnosed clinically with intra-articular and hip joint related symptoms. Cam-type FAI, mixed-type FAI, increasing alpha angle, and increasing Tönnis grade were independent predictors of clinically suspected intra-articular and hip joint symptoms (P < .001), whereas isolated Pincer-type morphology was not.

CONCLUSIONS

FAI is highly prevalent (96.6%) and frequently bilateral (83%) in patients presenting to an orthopaedic clinic with hip pain. Cam-type morphology and acetabular retroversion are more frequent in men, whereas profunda and protrusio are more frequent in women. Cam-type morphology, increasing alpha angle (larger cam morphology), and increasing Tönnis grade were highly predictive of clinically suspected intra-articular symptoms, whereas isolated pincer-type morphology was not.

LEVEL OF EVIDENCE

Level III, case-control study.

CLINICAL MEASURES OF HIP RANGE OF MOTION DO NOT CORRELATE WITH THE DEGREE OF CAM MORPHOLOGY IN SEMI-ELITE AUSTRALIAN FOOTBALLERS: A CROSS-SECTIONAL STUDY

Background

Clinical testing to determine the presence of a cam morphology is becoming more common however the correlation between hip range of motion and the degree of cam morphology remains controversial in the literature. The prevalence of a cam morphology in athletes has been reported as higher than in the general population but the prevalence of cam morphology has not been reported in Australian Football (AF).

Purpose

The purpose of this study was to determine the correlation between hip range of motion and hip alpha angle and report the proportion of players with a cam morphology in a sample of AF players.

Design

Cross-sectional Study.

Methods

Twenty-one semi-elite AF players (42 hips) from the Peel Thunder Football Club were included in this study. A hip Flexion Internal Rotation (IR) test and a modified maximal squat test using the difference in depth of squat in hip internal and external rotation were used. These measures were then compared to alpha angles on 90 degree Dunn view x-rays.

Results

Four of the 42 hips (9.5%) had a cam morphology (alpha angle > 60 degrees). There was no significant correlation between alpha angle and ROM in a Flexion IR test or the difference in modified maximal squat test depth within this sample of players.

Conclusions

The proportion of cam morphology seems to be lower in this sample than the previously reported prevalence in other sports. The lack of correlations between hip range and hip alpha angle in players means that screening hips using clinical measures to detect cam morphology associated with poor hip range of motion may be inaccurate.

Level of Evidence

Level 3a.