Hip Arthroscopy for Femoroacetabular Impingement Syndrome in High-Level Athletes: A 10-Year Follow-up

Background

Arthroscopic treatment for femoroacetabular impingement syndrome (FAIS) has previously been reported to have favorable short-term results in high-level athletes. Less is known about long-term outcomes.

Purpose

To report outcomes 10 years after hip arthroscopy for FAIS in high-level athletes using validated patient-reported outcome measures (PROMs).

Study Design

Case series; Level of evidence, 4.

Methods

Patients who underwent hip arthroscopy between November 2011 and January 2013 were included in a local hip arthroscopy registry and completed preoperative PROMs. At 10-year follow-up, the same PROMs were completed. Inclusion criteria were age <40 years at time of surgery, no prior hip surgeries, and a pre-symptomatic Hip Sports Activity Scale (HSAS) level of 7 or 8. The exclusion criterion was total hip arthroplasty at follow-up. The PROMs included the international Hip Outcome Tool-12 items (iHOT-12), the Copenhagen Hip and Groin Outcome Score (HAGOS), visual analog scale (VAS) for overall hip function, European Quality of Life-5 Dimensions questionnaire (EQ-5D) and European Quality of Life-visual analog scale (EQ-VAS), HSAS, and a single question on patient satisfaction. The rates of patients achieving minimal important change and reporting Patient Acceptable Symptom State (PASS) were reported for HAGOS and iHOT-12. For iHOT-12, preoperative results were compared with 1, 5, and 10-year follow-ups.

Results

A total of 45 patients (34 men, 11 women; 70 hips; mean age 24.4 years at time of surgery) were included, with 77 patients eligible for inclusion. Significant improvements (P < .001) were seen at 10-year follow-up in all HAGOS subscales: Symptoms, Pain, Daily Activity, Sports, Physical Activity, Quality of Life (50.3 vs 78.6, 59.2 vs 86.8, 65.9 vs 88.8, 37.1 vs 81.1, 24.4 vs 81.1, 32.1 vs 79.3), iHOT-12 (40.1 vs 81.6), EQ-5D (0.59 vs 0.89), EQ-VAS (65.6 vs 80.4), and VAS for overall hip function (48 vs 79). For iHOT-12, the largest change was seen between preoperative and 1-year follow-up values, with consistent results over time. There was no statistically significant difference between HSAS levels preoperatively and at 10-year follow-up (HSAS level 4), with 24% of patients reporting a HSAS level 7 or 8 at the follow-up. Of the patients, 93% reported satisfaction with the surgery. PASS was achieved in 82% for iHOT-12, with a range of 76% to 91% for HAGOS subscales. Furthermore, 93% exceeded the minimal important change for iHOT-12, and a range of 67% to 84% for HAGOS.

Conclusion

In a high-level athletic population, significant improvements in long-term outcomes are reported after hip arthroscopy for FAIS, with patients reporting a high satisfaction rate. The results also show that the largest improvement occurs within the first postoperative year, with results being maintained for 10 years.

A Biomechanical Review of the Squat Exercise: Implications for Clinical Practice

The squat is one of the most frequently prescribed exercises in the rehabilitative setting. Performance of the squat can be modified by changing parameters such as stance width, foot rotation, trunk position, tibia position, and depth. An understanding of how the various squatting techniques can influence joint loading and muscular demands is important for the proper prescription of this exercise for various clinical conditions. The purpose of this clinical commentary is to discuss how the biomechanical demands of the squat can be influenced by various modifiable parameters. General recommendations for specific clinical conditions are presented.

Level of Evidence

5.

Hip Range of Motion During Passive and 1-Leg Exercises Is Greater in Women: A Meta-analysis and Systematic Review

PURPOSE

To summarize sex-related differences in hip range of motion (ROM), including flexion, extension, abduction, adduction, internal rotation, and external rotation.

METHODS

We performed a systematic search of 3 databases (PubMed, CINAHL [Cumulative Index to Nursing and Allied Health Literature], and Embase). The search terms were as follows: hip, pelvis, range of motion, kinematic, men, and women. Included studies reported sex-specific data on hip ROM in healthy, uninjured adults. To generate hip ROM mean differences, a DerSimonian-Laird random-effects model was used. Effect sizes were pooled for each exercise. Subgroup analyses compared hip ROM by physical activity group: passive ROM, 1-leg hop or jump, 2-leg hop or jump, 2-leg drop or landing, 1-leg squat, 2-leg squat, walking, and jogging/running. Positive effect sizes represent greater ROM in women.

RESULTS

Thirty-eight studies with 3,234 total subjects were included; of these subjects, 1,639 were women (50.1%). The mean age was 25.3 years. An effect difference was considered statistically significant if P < .05 and clinically significant if the mean difference was greater than 4.0°. Women showed statistically and clinically significantly greater hip flexion in passive ROM (mean difference, 6.4°) and during the 1-leg hop or jump exercise (mean difference, 6.5°). Women also showed statistically and clinically significantly greater hip adduction during the 1-leg hop or jump (mean difference, 4.5°) and 1-leg squat (mean difference, 4.4°) exercises, as well as statistically and clinically significantly greater hip internal rotation in passive ROM (mean difference, 8.2°). In contrast, men showed statistically and clinically significantly greater flexion during the 2-leg hop or jump exercise (mean difference, -9.1°). No clinically significant differences in extension, abduction, or external rotation were found between women and men.

CONCLUSIONS

On average, women showed statistically and clinically significantly greater flexion, adduction, and internal rotation during passive and 1-leg exercises whereas men showed statistically and clinically significantly greater flexion during the 2-leg hop or jump exercise.

LEVEL OF EVIDENCE

Level IV, meta-analysis and systematic review of Level II-IV studies.

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.

Extent of Cam Resection Relative to Epiphyseal Line and Its Association With Clinical Outcomes After Arthroscopic Treatment for Femoroacetabular Syndrome

Background:

Inadequate resection of cam lesions can cause inferior outcomes after hip arthroscopy and result in revision surgery for femoroacetabular impingement syndrome (FAIS).

Purpose:

To evaluate the association between postoperative cam lesions measured using the proximal boundaries of resection area (PBRE) relative to the epiphyseal line and 2-year outcomes after hip arthroscopy.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Included were patients with FAIS who had undergone primary hip arthroscopy between 2016 and 2018. The PBRE was calculated by measuring the linear distance from the PBRE to the epiphyseal line, dividing it by the diameter of the femoral head, and multiplying by 100; PBRE measurements were made at the 12-, 1-, and 2-o’clock positions on postoperative hip computed tomography. Within each clockface position, patients were divided into subgroups depending on whether their postoperative PBRE was greater than a half standard deviation above the mean (adequate resection) or less than or equal to a half standard deviation above the mean (inadequate resection). Patient-reported outcomes (PROs; Hip Outcome Score–Activities of Daily Living [HOS-ADL], International Hip Outcome Tool–Short Form [iHOT-12], modified Harris Hip Score [mHHS], and pain visual analog scale [VAS]) and rates of achieving the minimal clinically important difference (MCID) and patient-acceptable symptomatic state (PASS) were compared among the subgroups.

Results:

Included were 80 pairs of hips at 12 o’clock, 81 pairs of hips at 1 o’clock, and 80 pairs of hips at 2 o’clock. All subgroups demonstrated significant improvements in PRO scores at a minimum 2-year follow-up compared with preoperatively. At the 12-o’clock position, the subgroup with adequate resection had significantly superior HOS-ADL ( P = .004), iHOT-12 ( P < .001), and mHHS ( P < .001) scores and were more likely to achieve the MCID for the iHOT-12 score ( P = .035) and the PASS for the HOS-ADL ( P = .003), iHOT-12 ( P = .007), and mHHS ( P < .001) scores compared with the matched subgroup. There were no significant differences in PRO scores or rates of MCID and PASS for the 1- or 2-o’clock groups.

Conclusion:

The epiphyseal line may be a useful and reproducible landmark measurement for cam-type deformity. Patients considered to have inadequate resection at 12 o’clock had lower outcome scores at a minimum 2-year follow-up.

Return to Sport for Professional and Subelite Ice Hockey Players After Arthroscopic Surgery for Femoroacetabular Impingement Syndrome

Background:

Femoroacetabular impingement syndrome (FAIS) is a common cause of hip pain, which can prevent ice hockey players from sports participation. Hip arthroscopy is often performed to relieve pain and enable the player to return to sport (RTS) and return to performance (RTP).

Purpose:

To determine the RTS and RTP rates for ice hockey players at the professional and subelite levels after hip arthroscopy for FAIS.

Study Design:

Case series; Level of evidence, 4.

Methods:

High-level ice hockey players who underwent hip arthroscopy for FAIS between 2011 and 2019 were identified using a local hip arthroscopy registry. The player’s level was confirmed with ice hockey–specific web pages and was stratified as subelite or professional. Data on the players’ careers were extracted from these web pages. Player position was divided into goalkeepers, defensemen, and forwards. Data on participation in games included the season before onset of symptoms, the season before surgery, and the first and second seasons after surgery. RTS was defined as returning to ice hockey after surgery, and RTP was considered as returning to the same league at a comparable level to before symptoms.

Results:

A total of 80 ice hockey players were included. Comparing presymptom performance with the first season after surgery, the RTS rate was 72%, of which 94% of the players returned to the same or higher level of play. Comparing the presurgery season with the first season after surgery, the RTS rate was 78%. At the second season after surgery, 64% of players still played ice hockey, with a significantly higher return rate among professional players compared with subelite players (96% vs 69%; P = .014). Overall, 85% goalkeepers, 74% forwards, and 60% defensemen returned to sport. Only 28% played at least the same number of games during the first season after surgery as they did during the presymptom season.

Conclusion:

High-level ice hockey players who underwent hip arthroscopy for FAIS had a high RTS rate, in which the majority returned to the same league. However, only 28% played the same number of games the first season after surgery as they did at the presymptom level. Professional ice hockey players returned more frequently than players on the subelite level.

Hip Arthroscopy for Femoroacetabular Impingement-Associated Labral Tears: Current Status and Future Prospects

Femoroacetabular impingement (FAI) has emerged as a common cause of hip pain, especially in young patients. While the exact cause of FAI is unknown, it is thought to result from repetitive microtrauma to the proximal femoral epiphysis leading to abnormal biomechanics. Patients typically present with groin pain that is exacerbated by hip flexion and internal rotation. Diagnosis of FAI is made through careful consideration of patient presentation as well as physical exam and diagnostic imaging. Use of radiographs can help diagnose both cam and pincer lesions, while the use of MRI can diagnose labral tears and cartilage damage associated with FAI. Both non-operative and surgical options have their role in the treatment of FAI and its associated labral tears; however, hip arthroscopy has had successful outcomes when compared with physical therapy alone. Unfortunately, chondral lesions associated with FAI have had poorer outcomes with a higher conversion rate to arthroplasty. Capsular closure following hip arthroscopy has shown superior clinical outcomes and therefore should be performed if possible. More recently, primary labral reconstruction has emerged in the literature as a good option for irreparable labral tears. While non-operative management may have its role in treating patients with FAI, hip arthroscopy has developed a successful track record in being able to treat cam and pincer lesions, chondral damage, and labral injuries.

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.

High rate of return to tennis after hip arthroscopy for patients with femoroacetabular impingement syndrome

OBJECTIVE

The purpose of this study was to evaluate return to sport (RTS) outcomes in tennis athletes following hip arthroscopy for femoroacetabular impingement syndrome (FAIS). It was hypothesized that there would be a high rate of return to tennis after hip arthroscopy.

STUDY DESIGN

Level IV, Retrospective Analysis.

SETTING

Outpatient sports medicine clinic at a single institution.

PARTICIPANTS

A total of 28 patients (60.8% female; mean age, 36.2 ± 9.2 years; mean BMI, 22.8 ± 2.1 kg/m²) with self reported tennis activity prior to hip arthroscopy.

MAIN OUTCOME MEASURES

A postoperative return to sport and minimum two-year patient reported outcomes.

RESULTS

There was a high rate of return to tennis, with 78% of patients eventually returning to tennis. An additional 9% of patients had the necessary hip function to return, but did not return due to lack of interest or resources. The patients returned to tennis at an average of 8.0 ± 3.3 months after surgery. The majority of athletes (66.7%) were able to continue competing at the same or higher levels following surgery.

CONCLUSIONS

Patients return to tennis 78% of the time at a mean of 8.0 ± 3.3 months following hip arthroscopy for FAIS.

Influence of loading direction due to physical activity on proximal femoral growth tendency

Longitudinal bone growth is regulated by mechanical forces arising from physical activity, whose directions and magnitudes depend on activity kinematics and intensity. This study aims to investigate the influence of common physical activities on proximal femoral morphological tendency due to growth at the femoral head growth plate. A subject-specific femur model based on magnetic resonance images of one able-bodied 6-year old child was developed, and the directions of hip contact force were described as load samples at a constant magnitude. Finite element analysis was performed to predict growth rate and growth direction, and expected changes in neck-shaft angle and femoral anteversion were computed corresponding to circa 4 months of growth. For most loading conditions, neck-shaft angle and femoral anteversion decreased during growth, corresponding to the femur's natural course during normal growth. The largest reduction in neck-shaft angle and femoral anteversion was approximately 0.25° and 0.15°. Our results suggest that most common physical activities induce the expected morphological changes in normal growth in able-bodied children. Understanding the influence of contact forces during less common activities on proximal femoral development might provide improved guidelines and treatment planning for children who have or are at risk of developing a femoral deformity.

Femoroacetabular Impingement and Acetabular Labral Tears - Part 1: Pathophysiology and Biomechanics

Femoroacetabular impingement (FAI) is an important cause of hip pain, and the main etiology of hip osteoarthritis in the young population. Femoroacetabular impingement is characterized by subtle alterations in the anatomy of the acetabulum and proximal femur, which can lead to labrum tearing. The acetabular labrum is essential to the stability of the hip joint. Three types of FAI were described: cam (anespherical femoral head), pincer (acetabular overcoverage) and mixed (characteristics of both cam and pincer). The etiology of FAI is related to genetic and environmental characteristics. Knowledge of this condition is essential to adequately treat patients presenting with hip pain.

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.

Five-Year Outcomes After Arthroscopic Surgery for Femoroacetabular Impingement Syndrome in Elite Athletes

BACKGROUND

Femoroacetabular impingement syndrome (FAIS) is a common cause of hip pain and disability in athletes. Arthroscopic treatment for FAIS is well-established; however, the long-term results in elite athletes are limited.

PURPOSE

To evaluate outcomes 5 years after arthroscopic treatment for FAIS in elite athletes.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Elite athletes undergoing arthroscopic treatment for FAIS with a minimum 5-year follow-up were included. They were prospectively followed up with patient-reported outcome measures. An elite athlete was defined as having a Hip Sports Activity Scale (HSAS) level of 7 or 8 before the onset of symptoms. Preoperatively and 5 years after surgery, all athletes completed a web-based questionnaire, including the Copenhagen Hip and Groin Outcome Score (comprising 6 subscales), the EQ-5D and EQ-VAS (European Quality of Life-5 Dimensions Questionnaire and European Quality of Life-Visual Analog Scale), iHOT-12 (International Hip Outcome Tool), a visual analog scale for hip function, and the HSAS. Moreover, patients reported their overall satisfaction with their hip function. Preoperative measurements were compared with the 5-year follow-up.

RESULTS

A total of 64 elite athletes (52 men, 12 women) with a mean ± SD age of 24 ± 6 years were included. On average, patients reported a statistically significant and clinically relevant improvement from preoperative patient-reported outcome measures to the 5-year follow-up (P < .0003), Copenhagen Hip and Groin Outcome Score subscales (symptoms, 51.7 vs 71.9; pain, 61.0 vs 81.1; function of daily living, 67.1 vs 83.6; function in sports and recreation, 40.0 vs 71.5; participation in physical activity, 25.0 vs 67.4; hip and groin-related quality of life, 34.4 vs 68.0), EQ-5D (0.60 vs 0.83), EQ-VAS (66.1 vs 76.7), and iHOT-12 (40.0 vs 68.8). At the 5-year follow-up, 90.5% reported satisfaction with their overall hip function. In total, 54% still participated in competitive sports (HSAS, 5-8) at follow-up, while 77% had decreased their level. Older patients and patients with longer duration of symptoms reported a significantly lower level of sports activity (HSAS, 0-4; P < .009).

CONCLUSION

Arthroscopic treatment for FAIS in elite athletes results in a statistically significant and clinically relevant improvement regarding symptoms, hip function, quality of life, and pain 5 years after surgery. Approximately half of the cohort was still in competitive sports at follow-up, yet 77% had decreased their level of sports. Nine of 10 patients were satisfied with their surgery.

A Sport-specific Analysis of the Epidemiology of Hip Injuries in National Collegiate Athletic Association Athletes From 2009 to 2014

PURPOSE

To describe the injury rates, mechanisms, time loss, and rates of surgery for hip/groin injuries in National Collegiate Athletic Association (NCAA) athletes across 25 collegiate sports during the 2009/10 to 2013/14 academic years.

METHODS

Data from the 2009/10 to 2013/14 academic years were obtained from the NCAA Injury Surveillance Program (ISP). Rates of hip/groin injuries, mechanism of injury, time lost from competition, and surgical treatment were calculated. Differences between sex-comparable sports were quantified using rate ratios and injury proportion ratios. A sport-specific biomechanical classification system, which included cutting, impingement, overhead/asymmetric, endurance, and flexibility sports, was applied for subgroup analysis.

RESULTS

In total, 1,984 hip injuries were reported in 25 NCAA sports, including 9 male and female sports, 3 male-only sports, and 4 female-only sports between the years 2009/10 and 2013/14, resulting in an overall hip injury rate of 53.1/100,000 athletic exposures (AEs). In sex-comparable sports, (basketball, cross-country, lacrosse, ice hockey, indoor track, outdoor track, soccer, swimming, and tennis), men were more commonly affected than women (59.53 vs 42.27 per 100,000 AEs respectively; rate ratio, 1.41; 95% confidence interval, 1.28-1.55). Subgroup analysis demonstrated that the highest rate of hip injuries per 100,000 AEs occurred in impingement sports (96.9). Endurance sports had the highest proportion of injured athletes with time lost >14 days (9.5%). For impingement-type sports, the most common mechanism of injury was no apparent contact (48.2%). The rate of athletes undergoing surgery per 100,000 AEs was highest in impingement-type sports (2.0).

CONCLUSIONS

We have identified that impingement-type sports are most frequently associated with hip injuries. Additionally, this study demonstrates that hip injuries sustained in athletes who played impingement-type sports had a significantly higher rate of surgical intervention than other sport classifications.

LEVEL OF EVIDENCE

Level III, prognostic study.

Health-Related Quality of Life After Hip Arthroscopy for Femoroacetabular Impingement: A Systematic Review and Meta-analysis

CONTEXT

Hip pain from femoroacetabular impingement (FAI) can impair health-related quality of life (HRQL) but can be treated via hip arthroscopy techniques.

OBJECTIVE

To systematically assess the HRQL outcomes after arthroscopic management of FAI.

DATE SOURCES

Three online databases (EMBASE, PubMed, and Ovid [MEDLINE]) were searched for relevant literature from database inception until June 2018 and screened by 2 reviewers independently and in duplicate.

STUDY SELECTION

Level I to IV English studies that investigated HRQL outcomes after hip arthroscopy were included. Data for generic and hip-specific HRQL outcomes were collected. Mean differences were plotted in a forest plot when possible.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

A total of 29 studies were included for assessment. Of the 6476 patients (6959 hips), the mean age was 32 years (range 9-79 years) and 50.7% were female. Significant improvements were reported in all studies assessing generic HRQL outcomes, including the 12-Item Short Form Health Survey (range of mean postoperative scores, 82.2-89.8), and EuroQOL-5D scores (range of mean postoperative scores, 0.74-0.87) between 12 and 24 months postoperatively. Significant improvements were similarly identified in the hip-specific HRQL outcomes scores, with the majority of studies also reporting improvement between 12 and 24 months postoperatively. Mean improvement in International Hip Outcome Tool-33 scores from preoperative values to postoperative values ranged from 22.7 to 43.2 ( I2 = 44%), for studies with follow-up between 12 and 24 months.

CONCLUSION

Hip arthroscopy can lead to significant improvement in generic and hip-specific HRQL outcomes at 12 to 24 months postoperatively in patients with FAI who do not have advanced hip osteoarthritis. Confirmatory, high-quality, prospective studies are warranted to compare this observed improvement with other treatment modalities for FAI and to determine long-term outcomes.

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 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.

Epidemiology of Hip and Groin Injuries in Collegiate Athletes in the United States

Background:

Hip and groin pain is a common complaint among athletes. Few studies have examined the epidemiology of hip and groin injuries in collegiate athletes across multiple sports.

Purpose:

To describe the rates, mechanisms, sex-based differences, and severity of hip/groin injuries across 25 collegiate sports.

Study Design:

Descriptive epidemiology study.

Methods:

Data from the 2009-2010 through 2013-2014 academic years were obtained from the National Collegiate Athletic Association Injury Surveillance Program (NCAA ISP). The rate of hip/groin injuries, mechanism of injury, time lost from competition, and need for surgery were calculated. Differences between sex-comparable sports were quantified using rate ratios (RRs) and injury proportion ratios (IPRs).

Results:

In total, 1984 hip/groin injuries were reported, giving an overall injury rate of 53.06 per 100,000 athlete-exposures (AEs). An adductor/groin tear was the most common injury, comprising 24.5% of all injuries. The sports with the highest rates of injuries per 100,000 AEs were men’s soccer (110.84), men’s ice hockey (104.90), and women’s ice hockey (76.88). In sex-comparable sports, men had a higher rate of injuries per 100,000 AEs compared with women (59.53 vs 42.27, respectively; RR, 1.41 [95% CI, 1.28-1.55]). The most common injury mechanisms were noncontact (48.4% of all injuries) and overuse/gradual (20.4%). In sex-comparable sports, men had a greater proportion of injuries due to player contact than women (17.0% vs 3.6%, respectively; IPR, 4.80 [95% CI, 3.10-7.42]), while women had a greater proportion of injuries due to overuse/gradual than men (29.1% vs 16.7%, respectively; IPR, 1.74 [95% CI, 1.46-2.06]). Overall, 39.3% of hip/groin injuries resulted in time lost from competition. Only 1.3% of injuries required surgery.

Conclusion:

Hip/groin injuries are most common in sports that involve kicking or skating and sudden changes in direction and speed. Most hip/groin injuries in collegiate athletes are noncontact and do not result in time lost from competition, and few require surgery. This information can help guide treatment and prevention measures to limit such injuries in male and female collegiate athletes.

Outcomes of intra-articular corticosteroid injections for adolescents with hip pain

Intra-articular injection of corticosteroid and anesthetic (CSI) is a useful diagnostic tool for hip pain secondary to labral tears or femoroacetabular impingement (FAI). However, the effectiveness of CSI as a stand-alone treatment for hip pain in adolescents is unknown. The purpose of this study is to evaluate the use of CSI for the treatment of hip pain and determine factors that may affect outcomes after injection. Retrospective analysis of 18 patients and 19 hips that underwent fluoroscopic guided hip injection for the treatment of pain at a single institution from 2012 to 2015 was carried out in this study. Mean age at the time of injection was 15.1 years (range 13–17) with mean follow-up of 29.4 months. Fifty-two percent (10/19 hips) went on to surgery after the injection. Average time to surgical conversion was 12.8 months after CSI. Cam or pincer morphologies were present in 90% (9/10 hips) of the operative group. Patients with FAI were more likely to need surgery than patients without bony abnormalities (RR= 10, 95% CI 1.6–64.2, P = 0.0001). There was no difference in the presence of labral tears in the operative and non-operative groups (100% versus 89%, P = 0.47). For adolescents without bony abnormalities, 90% improved with CSI alone and did not require further treatment within 2.4 years. Fluoroscopic guided corticosteroid hip injection may have limited efficacy for the treatment of hip pain secondary to FAI in adolescents. However, for patients without osseous deformity, CSI may offer prolonged improvement of symptoms even in the presence of labral tears.

Prevalence of asymptomatic femoroacetabular impingement in Turkey; cross sectional study

OBJECTIVES

Femoroacetabular impingement (FAI) is one of the causes of hip pain in young-adult patients. The purpose of our study is to determine the prevalence of radiological FAI findings in asymptomatic population in Turkey.

METHODS

Trauma patients aged 18-65 years who applied to the emergency service between September 2015 and September 2016 were retrospectively evaluated for this study. After a preliminary study and power analysis, 2152 hips of the 1076 previously asymptomatic patients were evaluated radiologically with pelvis antero-posterior and frog-leg radiographs. On radiographs of these patients; alpha angle, lateral central edge angle (LCEA), Tönnis angle (TA) and collodiaphyseal angle were measured. Alpha angle values higher than 55° were noted as cam type FAI. TA values lower than 0° or LCEA values higher than 39° were noted as pincer type FAI. LCEA values lower than 25° or TA values higher than 10° were noted as acetabular dysplasia.

RESULTS

Mean age of 1076 patients (602 female, 474 male) was 42.1 ± 15.6 years. The assessment showed that 15.9% of the patients had cam type, 10.6% had pincer type, 3.1% had combined type FAI and 9.3% had findings of acetabular dysplasia. The prevalence of asymptomatic FAI is significantly more in males (46%) in comparison to females (17%) in Turkey.

CONCLUSION

Even though FAI is considered to be a pathology associated with hip osteoarthritis; it is very common in asymptomatic population. In this respect, our study showed that prevalence of radiological FAI findings in asymptomatic adult population was 29.6% in Turkey.

Cam Deformities and Limited Hip Range of Motion Are Associated With Early Osteoarthritic Changes in Adolescent Athletes: A Prospective Matched Cohort Study

BACKGROUND

The natural history of femoroacetabular impingement (FAI) remains incompletely understood. In particular, there is limited documentation of joint damage in adolescent patients with limited range of motion (LROM) of the hip, which is commonly associated with FAI.

PURPOSE

To evaluate changes in magnetic resonance imaging (MRI), radiographs, and clinical examinations over 5 years in a group of athletes from a wide variety of sports with asymptomatic LROM of the hip compared with matched controls.

STUDY DESIGN

Cohort study (prognosis); Level of evidence, 2.

METHODS

The authors screened 226 male and female athletes aged 12 to 18 years presenting for preparticipation sports physical examinations. Using a goniometer, we identified 13 participants with at least one hip having internal rotation <10° with the hip flexed to 90°. Overall, 21 of 26 hips (81%) had internal rotation <10°. These participants were age- and sex-matched to 13 controls with internal rotation >10°. At the time of enrollment, all participants were asymptomatic and underwent a complete hip examination and radiographic imaging with radiographs (anteroposterior [AP] and von Rosen views) and non-arthrogram MRI. Participants returned at 5-year follow-up and underwent repeat hip examinations, imaging (AP and lateral radiographs and non-arthrogram MRI), and hip function questionnaires. MRI scans were classified as "normal" versus "abnormal" based on the presence of any of 13 scored chondral, labral, or osseous abnormalities. Comparisons between the LROM group and control group were performed using generalized linear models (either linear, logistic, or log-binomial regression as appropriate for the outcome) with generalized estimating equations to account for the within-participant correlation due to patients having both hips included. Relative risk (RR) estimates are reported with 95% CIs.

RESULTS

At the time of study enrollment, 16 of 26 hips (62%) in the LROM group had abnormal MRI findings within the acetabular labrum or cartilage compared with 8 of 26 hips (31%) in the control group (RR, 2.0; 95% CI, 0.95-4.2; P = .067). The mean alpha angle measured from radial MRI sequences was 58° in the LROM group versus 44° in the control group ( P < .0001). In the LROM group, 13 of 26 hips (50%) had a positive anterior impingement sign, whereas 0 of 26 hips (0%) had a positive anterior impingement sign in the control group. At 5-year follow-up, 18 of 19 hips (95%) in the LROM group had abnormal MRI findings compared with 14 of 26 hips (54%) in the control group (RR, 1.7; 95% CI, 1.1-2.7; P = .014). New or progressive findings were documented on MRI in 15 of 20 hips in the LROM group compared with 8 of 26 hips in the control group (RR, 2.4; 95% CI, 1.2-4.8; P = .011). Six of 22 hips (27%) in the LROM group progressed from Tönnis grade 0 to Tönnis grade 1 in degenerative changes, whereas all 26 hips in the control group remained at Tönnis grade 0 on hip radiographs. In the LROM group, 11 of 22 hips (50%) had a positive anterior impingement sign, whereas 1 of 26 hips (4%) had a positive anterior impingement sign in the control group. A cam deformity (alpha angle >55° on lateral radiographs) was present in 20 of 22 hips (91%) in the LROM group and 12 of 26 hips (46%) in the control group ( P = .0165). The following variables at baseline were associated with an increased risk of degenerative changes at 5-year follow-up for the entire cohort: decreased hip internal rotation, positive anterior impingement sign, decreased hip flexion, increased alpha angle, and presence of a cam lesion.

CONCLUSION

At 5 years, young athletes with LROM of the hip showed increased progressive degenerative changes on MRI and radiographs compared with matched controls. Although the majority of these participants remained asymptomatic, those with features of FAI had radiographic findings consistent with early osteoarthritis. These outcomes suggest that more aggressive screening and counseling of young active patients may be helpful to prevent hip osteoarthritis in those with FAI.

Prevalence of femoroacetabular impingement morphology in asymptomatic youth soccer players: magnetic resonance imaging study with clinical correlation

OBJECTIVE

To determine the prevalence of femoroacetabular impingement morphology (FAIM), cam- or pincer-type, by magnetic resonance imaging (MRI) in asymptomatic adolescent soccer players, and to evaluate the possible correlation between alterations on MRI and clinical examination findings.

METHODS

A cross-sectional study was conducted to determine the prevalence of FAIM in asymptomatic youth soccer players aged 13-18 years. A total of 112 hips in 56 players (mean age 15.3 years) were evaluated by MRI. Images were examined by two musculoskeletal radiologists for signs of FAIM. Cam-type (impingement) deformity was diagnosed by alpha angle ≥55° or head-neck offset <7 mm. Pincer-type (impingement) deformity was diagnosed by center-edge angle (CEA) ≥35° or acetabular index ≤0°. Other MRI changes, characteristic of FAIM, were observed. Clinical examination was performed to determine the range of motion (ROM) of the hips. In addition, specific tests for anterolateral and posteroinferior impingement were performed.

RESULTS

The prevalence of MRI findings consistent with FAIM among this young population was 84.8% (95/112). The alpha angle was ≥55° in 77.7% (87/112) of hips, while the CEA was altered in 10.7% (12/112) of hips. Qualitative MRI findings consistent with FAIM were highly prevalent, and included loss of sphericity of the femoral head (77%), osseous bump (44%), femoral neck edema (21%), and acetabular osteitis (9%). The anterior impingement test was positive in 15% of the hips evaluated.

CONCLUSION

Youth soccer players have a high prevalence of FAIM as diagnosed by MRI. There is no correlation between physical examination findings and MRI evidence of FAIM in this population.

Histology of damaged acetabular cartilage in symptomatic femoroacetabular impingement: an observational analysis

This prospective study on symptomatic adult patients with femoroacetabular impingement (FAI) who underwent open surgical intervention for management was designed to identify any obvious histological differences in the damaged acetabular cartilage within different subgroups of FAI. 20 patients underwent surgical intervention following safe surgical dislocation of the hip. There were 6 cases of cam impingement, 5 cases of pincer impingement and 9 of the mixed type. Pincer impingement cases demonstrated a characteristic focal, well-circumscribed and localized area of severe damage. On the other hand, cases with cam impingement showed a diffuse area of involvement affecting a larger surface of the acetabular cartilage, with degenerative changes, superficial erosions and some discontinuities. A small biopsy specimen of the acetabular rim including bone, cartilage and labrum from the affected zone was obtained in all cases. Histological evaluation was performed under normal and polarized light microscopy. Histological findings helped corroborate the pre-operative diagnosis and also define the unique nature of impingement and specific damage according to the type of impingement.

Correlation Between Cam-Type Femoroacetabular Impingement and Radiographic Osteitis Pubis

A mechanistic link has been suggested between cam-type femoroacetabular impingement and increased stress on the symphysis pubis. This retrospective study was conducted to determine whether there is an increased prevalence of osteitis pubis, as evidenced by imaging, in patients with femoroacetabular impingement compared with age-matched control subjects. Search of a radiologic database of a large academic health institution for all patients with cam-type femoroacetabular impingement diagnosed by magnetic resonance imaging or magnetic resonance arthrogram between January 2000 and October 2013 identified 46 cases. Two radiologists reviewed these cases independently and confirmed the presence of femoroacetabular impingement based on alpha angle and other characteristics of cam morphology. The imaging studies were further evaluated for characteristics of osteitis pubis, with severity graded from minimal to severe on a 4-point Likert scale. A control group composed of age-matched subjects without diagnosed femoroacetabular impingement was also evaluated for osteitis pubis. A statistically significant increase in the prevalence of osteitis pubis was found in patients with femoroacetabular impingement compared with age-matched control subjects, with a prevalence of 43.48% in the femoroacetabular impingement group compared with 12.77% in the control group (P=.0012). On the 4-point Likert scale, the average severity of osteitis pubis in the group with femoroacetabular impingement was 1.5 (minimal to mild) compared with 0.53 (no osteitis pubis to minimal findings) in the control population. This significant increase in osteitis pubis in patients with femoroacetabular impingement supports the clinical link between these 2 processes. [Orthopedics. 2016; 39(3):e417-e422.].

Physical and functional outcomes following multidisciplinary residential rehabilitation for prearthritic hip pain among young active UK military personnel

Background

There are no studies describing the clinical outcomes of a residential, multidisciplinary team (MDT) rehabilitation intervention for patients with prearthritic hip pain. The aim of this cohort study was to describe the functional and physical outcomes of multidisciplinary residential rehabilitation for UK military personnel with prearthritic hip pain.

Methods

Participants (N=40) with a mean age of 33 years referred to a specialist residential rehabilitation centre completed a comprehensive multidisciplinary residential intervention. The main outcome measures were mean pain, physical function (modified shuttle test (MST) and Y-balance test), hip range of motion (HROM) and a patient-reported outcome measure (The Copenhagen Hip and Groin Outcome Score, HAGOS). All scores for symptomatic hips were taken at baseline and post-treatment.

Results

There were improvements in the Y-balance test and HROM following rehabilitation. There were significant improvements in mean difference (T1-to-T2) for Y-balance scores (15.8 cm, 95% CI 10.7 to 20.9, p<0.001), HROM (6.5° increase in hip flexion, 95% CI 4.6 to 9.4, p<0.001) and hip internal rotation (4.6°, 95% CI 2.7 to 6.6, p<0.001). Scores for HAGOS, pain, MST and functional activity assessment showed no improvement.

Conclusions

Among UK military personnel with prearthritic hip pain, MDT residential rehabilitation resulted in improvements in a functional Y-balance test, hip flexion and internal rotation. The study suggests short-term benefits across some outcomes for the current UK military approach to MDT residential rehabilitation.

Does high level youth sports participation increase the risk of femoroacetabular impingement? A review of the current literature

Sports participation can be an integral part of adolescent development with numerous positive short and long-term effects. Despite these potential benefits very high levels of physical activity, during skeletal maturation, have been proposed as a possible cause of cam-type femoroacetabular impingement (FAI). The influence of physical activity on the developing physis has been previously described both in animal studies and epidemiological studies of adolescent athletes. It is therefore important to determine whether the development of FAI is secondary to excessive physical activity or a combination of a vulnerable physis and a set level of physical activity. A review of the current literature suggests that adolescent males participating in ice-hockey, basketball and soccer, training at least three times a week, are at greater risk than their non-athletic counterparts of developing the femoral head-neck deformity associated with femoroacetabular impingement.

Femoroacetabular Impingement in Elite Ice Hockey Goaltenders: Etiological Implications of On-Ice Hip Mechanics

BACKGROUND

Femoroacetabular impingement (FAI) is particularly prevalent in ice hockey. The butterfly goalie technique is thought to involve extreme ranges of hip motion that may predispose goaltenders to FAI.

PURPOSE

To quantify hip mechanics during 3 common goaltender movements and interpret their relevance to the development of FAI.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Fourteen collegiate and professional goaltenders performed skating, butterfly save, and recovery movements on the ice. Hip mechanics were compared across the 3 movements.

RESULTS

The butterfly did not exhibit the greatest range of hip motion in any of the 3 planes. Internal rotation was the only hip motion that appeared close to terminal in this study. When subjects decelerated during skating—shaving the blade of their skate across the surface of the ice—the magnitude of peak hip internal rotation was 54% greater than in the butterfly and 265% greater than in the recovery. No movement involved levels of concomitant flexion, adduction, and internal rotation that resembled the traditional impingement (FADIR) test.

CONCLUSION

The magnitude of internal rotation was the most extreme planar hip motion (relative to end-range) recorded in this study (namely during decelerating) and appeared to differentiate this cohort from other athletic populations. Consequently, repetitive end-range hip internal rotation may be the primary precursor to symptomatic FAI in hockey goaltenders and provides the most plausible account for the high incidence of FAI in these athletes. Resection techniques should, therefore, focus on enhancing internal rotation in goaltenders, compared with flexion and adduction. While the butterfly posture can require significant levels of hip motion, recovering from a save and, in particular, decelerating during skating are also demanding on goaltenders' hip joints. Therefore, it appears critical to consider and accommodate a variety of sport-specific hip postures to comprehensively diagnose, treat, and rehabilitate FAI.

Development of Bilateral Cam Deformity After Dunn Procedure and Contralateral Prophylactic Fixation: A Periosteal Reaction?: A Case Report

CASE

We present the case of a fourteen-year-old male athlete with a slipped capital femoral epiphysis who was managed with a unilateral Dunn procedure and contralateral prophylactic screw fixation. Even though the cartilaginous epiphyseal growth plate was removed on one side, cam deformities subsequently developed on both sides in the postoperative period.

CONCLUSION

This case suggests that structures other than the growth plate are also capable of inducing cam deformity of the hip.

On-Ice Functional Assessment of an Elite Ice Hockey Goaltender After Treatment for Femoroacetabular Impingement

BACKGROUND

Femoroacetabular impingement (FAI) is a major cause of performance inhibition in elite-level athletes. The condition is characterized by pain, osseous abnormalities such as an increased alpha angle, and decreased range of motion at the affected hip joint. Arthroscopic surgical decompression is useful in reshaping the joint to alleviate symptoms. Functional kinematic outcomes of sport-specific movements after surgery, however, are presently unknown.

HYPOTHESIS

The ability of an ice hockey goaltender to execute sport-specific movements would improve after arthroscopic surgery.

STUDY DESIGN

Clinical research.

LEVEL OF EVIDENCE

Level 5.

METHODS

An ice hockey goaltender was evaluated after arthroscopic correction of FAI on the symptomatic hip. Passive range of motion and radiographic parameters were assessed from a computed tomography-derived 3-dimensional model. An on-ice motion capture system was also used to determine peak femoral shock and concurrent hip joint postures during the butterfly and braking movements.

RESULTS

Maximum alpha angles were 47° in the surgical and 61° in the nonsurgical hip. Internal rotation range of motion was, on average, 23° greater in the surgically corrected hip compared with contralateral. Peak shock was lower in the surgical hip by 1.39 g and 0.86 g during butterfly and braking, respectively. At peak shock, the surgical hip demonstrated increased flexion, adduction, and internal rotation for both tasks (butterfly, 6.1°, 12.3°, and 30.8°; braking, 14.8°, 19.2°, and 41.4°).

CONCLUSION

On-ice motion capture revealed performance differences between hips after arthroscopic surgery in a hockey goaltender. Range of motion and the patient's subjective assessment of hip function were improved in the surgical hip. While presenting as asymptomatic, it was discovered that the contralateral hip displayed measurements consistent with FAI. Therefore, consideration of preemptive treatment in a presently painless hip may be deemed beneficial for young athletes seeking a long career in sport, and future work is needed to determine the costs and benefits of such an approach.

CLINICAL RELEVANCE

Surgical treatment of symptomatic FAI can achieve pain relief and improved kinematics of the hip joint with athletic activities. Additional studies are necessary to determine whether improved kinematics enhance the longevity of the native hip and alter the progression of osteoarthritic changes in those with asymptomatic FAI deformity.

Mechanical factors explain development of cam-type deformity

OBJECTIVE

A cam-type deformity drastically increases the risk of hip osteoarthritis (OA). Since this type of skeletal anomaly is more prevalent among young active adults, it is hypothesized that the loading conditions experienced during certain types of vigorous physical activities stimulates formation of cam-type deformity. We further hypothesize that the growth plate shape modulates the influence of mechanical factors on the development of cam-type deformity.

DESIGN

We used finite element (FE) models of the proximal femur with an open growth plate to study whether mechanical factors could explain the development of cam-type deformity in adolescents. Four different loading conditions (representing different types of physical activities) and three different levels of growth plate extension towards the femoral neck were considered. Mechanical stimuli at the tissue level were calculated by means of the osteogenic index (OI) for all loading conditions and growth plate shape variations.

RESULTS

Loading conditions and growth plate shape influence the distribution of OI in hips with an open growth plate, thereby driving the development of cam-type deformity. In particular, specific types of loads experienced during physical activities and a larger growth plate extension towards the femoral neck increase the chance of cam-type deformity.

CONCLUSIONS

Specific loading patterns seem to stimulate the development of cam-type deformity by modifying the distribution of the mechanical stimulus. This is in line with recent clinical studies and reveals mechanobiological mechanisms that trigger the development of cam-type deformity. Avoiding these loading patterns during skeletal growth might be a potential preventative strategy for future hip OA.

Asymptomatic hip/groin pathology identified on magnetic resonance imaging of professional hockey players: outcomes and playing status at 4 years' follow-up

PURPOSE

The purpose of this study was to evaluate the clinical outcomes and playing status of professional hockey players 4 years after they underwent bilateral magnetic resonance imaging (MRI) of asymptomatic hips.

METHODS

Twenty-one professional hockey players with no previous hip/groin pain underwent hip/pelvis MRI. Each MRI study was evaluated by 3 subspecialty-trained musculoskeletal radiologists for alpha-angle measurement and the presence of adductor-abdominal rectus abnormalities, acetabular labral tears, osteochondral lesions of the femoral head or acetabulum, hip effusion, adjacent muscle contusions or strain injury, and stress fractures. The MRI findings of the players were previously published. In the present study, each athlete was followed up by (1) completion of a questionnaire assessing hip/groin dysfunction at 1 and 2 years' follow-up and (2) number of games played over the course of the next 4 years. A significant difference in the number of games played was considered when a player missed more than 5 games compared with the index year.

RESULTS

We enrolled 21 players in the study. Of these players, 4 had no abnormality bilaterally, 10 had muscle strain and/or tendinosis in 1 or both hips, and 15 had labral tears identified in 1 or both hips. Eight players had a combination of labral tears and muscle strain/tendinosis. Of 21 professional hockey players, 16 (76%) and 14 (67%) were available at 1 and 2 years' follow-up, respectively. Nineteen of 21 players (90%) continued to play professional hockey at 4 years' follow-up. The development of any hip and/or pelvis symptoms occurred in only 3 players (14%) within 4 years. Only 1 of the 3 players missed any games because of hip and/or pelvis symptoms. The affected player missed several games because of proximal iliotibial band symptoms that occurred in the third year after MRI.

CONCLUSIONS

Hip/pelvis pathology is commonly uncovered on MRI of asymptomatic hockey players; however, this pathology does not produce symptoms or result in missed games within 4 years in most players.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

The human movement system: our professional identity

The 2013 House of Delegates of the American Physical Therapy Association adopted a vision statement that addresses the role of physical therapy in transforming society through optimizing movement. The accompanying guidelines address the movement system as key to achieving this vision. The profession has incorporated movement in position statements and documents since the early 1980s, but movement as a physiological system has not been addressed. Clearly, those health care professions identified with a system of the body are more easily recognized for their expertise and role in preventing, diagnosing, and treating dysfunctions of the system than health professions identified with intervention but not a system. This perspective article provides a brief history of how leaders in the profession have advocated for clear identification of a body of knowledge. The reasons are discussed for why movement can be considered a physiological system, as are the advantages of promoting the system rather than just movement. In many ways, a focus on movement is more restrictive than incorporating the concept of the movement system. Promotion of the movement system also provides a logical context for the diagnoses made by physical therapists. In addition, there is growing evidence, particularly in relation to musculoskeletal conditions, that the focus is enlarging from pathoanatomy to pathokinesiology, further emphasizing the timeliness of promoting the role of movement as a system. Discussion also addresses musculoskeletal conditions as lifestyle issues in the same way that general health has been demonstrated to be clearly related to lifestyle. The suggestion is made that the profession should be addressing kinesiopathologic conditions and not just pathokinesiologic conditions, as would be in keeping with the physical therapist's role in prevention and as a life-span practitioner.

Radiographic signs for detection of femoroacetabular impingement and hip dysplasia should be carefully used in patients with osteoarthritis of the hip

Background

During the last years, terms like acetabular retroversion, excessive overcoverage, and abnormal head-neck-junction with the so called “pistol-grip-deformity” has been added to the classical description of hip dysplasia. These anatomical changes could lead to a femoroacetabular impingement (FAI). Both kinds of FAI has been indentified as a main reason for hip pain and progressive degenerative changes leading to early osteoarthritis of the hip. A lot of radiographic criteria on pelvic views have been established to detect classical dysplasia and FAI. The present study was initiated to assess the hypothesis that age and severity of osteoarthritis affect measurements of different radiographic parameters.

Methods

The pelvic radiographs of 1614 patients were measured for head-ratio, CE-angle, roof obliquity, extrusion-index, depth-to-width ratio, CCD-angle, sharp’s angle. To evaluate the severity of osteoarthritis of the hip the classification by Kellgren and Lawrence was used. Associations between age and radiographic parameters or severity of osteoarthritis were assessed by Spearman’s (ρ) or Kendall’s (r) rank correlation coefficient, respectively.

Results

366 (22.7%) patients presented no sign of osteoarthritis, 367 (22.7%) patients presented I° osteoarthritis, 460 (28.5%) patients presented II° osteoarthritis, 307 (19%) III° osteoarthritis and 114 (7.1%) IV° osteoarthritis of the hip. The mean head-ratio of all patients was 1.13 ± 0.26 (0.76 – 2.40), the mean CE-angle 40.05° ± 10.13° (0° - 70°), the mean roof obliquity was 35.27°± 4.96° (10° – 55°), the mean extrusion-index was 12.99 ± 9.21 (6.20 – 95.2), the mean depth-to-width ratio was 59.30 ± 8.90 (6.30 – 100), the mean CCD-angle was 127.68° ± 7.22° (123° – 162°) and the mean sharp’s angle was 9.75° ± 5.40° (1° - 34°) There was a weak association between age and the severity of osteoarthritis of the hips (left: r = 0.291; right: r = 0.275; both P < 0.001) with higher osteoarthritis levels observable for elderly patients).

Conclusion

Severity of osteoarthritis has a negative impact on measurements of different radiographic parameters. Therefore - in our opinion - epidemiological studies on prearthrotic deformities should only be performed in healthy adults with no signs of osteoarthritic changes.

Do professional athletes perform better than recreational athletes after arthroscopy for femoroacetabular impingement?

BACKGROUND

Although a large number of athletes' returns to sports after hip arthroscopic surgery for femoroacetabular impingement (FAI), it is not clear if they do so to the preinjury level and whether professional athletes (PA) are more likely to return to the preinjury level compared with recreational athletes (RA).

QUESTIONS/PURPOSES

We therefore compared (1) the time taken to return to the preinjury level of sport between professional and recreational athletes; (2) the degree of improvement in time spent in training and competitive activities after arthroscopic surgery for FAI; and (3) the difference in trend of improvement in hip scores.

METHODS

We prospectively followed 80 athletes (PA = 40, RA = 40; mean age, 35.7 years; males = 50, females = 30; mean followup, 1.4 years; range, 1-1.8 years) who underwent hip arthroscopy for FAI. We measured the time to return to sports; training time and time in competition; and the modified Harris hip score and the nonarthritic hip score.

RESULTS

There was a 2.6-fold improvement in the training time (from 7.8 to 20 hours per week) and a 3.2-fold increase in time in competition (from 2.5 to 7.9 hours per week) 1 year after surgery. The mean time to return to sporting activities was 5.4 months, which was lower for PA (4.2) as compared with RA (6.8). Eighty-two percent (66) (PA = 88% [35] versus RA = 73% [29]) returned to their preinjury level of sport within 1 year of surgery.

CONCLUSIONS

The data suggest PA may show quicker return to sports than RA but the hip scores and rate of return to sports are similar.

Decreased range of motion is associated with structural hip deformity in asymptomatic adolescent athletes

BACKGROUND

Decreased hip range of motion (ROM) is a common finding in patients with femoroacetabular impingement (FAI).

PURPOSE

To report the prevalence of decreased hip ROM in asymptomatic adolescent athletes and to correlate examination findings to signs of FAI on radiographs and magnetic resonance imaging (MRI).

STUDY DESIGN

Cross-sectional study (prevalence); Level of evidence, 3.

METHODS

A total of 226 adolescent athletes presenting for state-mandated preparticipation physical examinations were assessed. Hip internal rotation was measured with the participant supine and the hip flexed to 90°. All participants with ≤10° of internal rotation were invited to return for standard radiographs and MRI of both hips. An age-matched control group, with >10° of internal rotation, underwent MRI examination only. Twenty-six athletes (13 study and 13 control) returned for clinical and radiographic examinations.

RESULTS

Nineteen athletes (34 hips, 8%) were found to have <10° of internal rotation. Eight athletes (13 hips, 3%) also had a positive anterior impingement sign. Thirteen of 19 athletes participated in the radiographic portion of the study. Of these 13 participants, 4 had limited internal rotation unilaterally, leaving 22 hips in the study group. Eight of 13 participants (15 hips, 68%) had a cam-type deformity evident on plain radiographs, and 4 participants (7 hips, 32%) had a positive radiographic crossover sign. The average α angle measured from radial MRI sequences was 58.1° in the study group versus 44.3° in the control group (P < .001). Fifteen hips (68%) in the study group had abnormal MRI findings within the acetabular labrum or cartilage compared with 10 of 26 hips (38%) in the control group (odds ratio, 3.4; P = .078).

CONCLUSION

Eight percent of asymptomatic teenagers had limited internal rotation on examination; 68% of these had radiographic findings suggestive of FAI. More than two thirds of these participants had evidence of asymptomatic hip pathological lesions on MRI.

Radiographic signs associated with femoroacetabular impingement occur with high prevalence at all ages in a hospital population

OBJECTIVES

Femoroacetabular impingement (FAI) is increasingly diagnosed clinically. Controversy exists about the significance of radiographic findings. Our goal is to determine the prevalence of radiographic FAI types and parameters in a hospital population clinically not suspected of having FAI. In addition we assessed whether pain, age and gender are associated with higher prevalences.

METHODS

Three hundred ten patients were included in this retrospective study. After applying the exclusion criteria, 262 patients (522 hips) remained. Two observers scored for radiographic parameters. A generalised estimation equation, Pearson's χ(2) test and logistic regression model were used.

RESULTS

Radiographic signs of FAI were absent in only 58 hips (11.1 %). In the 40 hips (7.7 %) with cam impingement, males were more affected (P < 0.001). In the 330 hips (63.2 %) with pincer impingement, females were more often affected (P < 0.001). In the 82 hips (15.7 %) with signs of mixed type impingement, male hips were significantly (P < 0.001) more often affected. Age had some effect on the prevalence of coxa vara, acetabular index and acetabular retroversion. No correlation with pain was found.

CONCLUSIONS

In this hospital population, signs occurred at a high rate. Radiographic parameters attributed to FAI are non-specific. Especially radiographic signs attributed to pincer type impingement have a high prevalence.

KEY POINTS

• Femoroacetabular impingement is associated with an abnormal configuration of the hip joint. • The prevalence of femoroacetabular impingement parameters was high in our study population. • The diagnosis of femoroacetabular impingement should be made clinically.

Prevalence of increased alpha angles as a measure of cam-type femoroacetabular impingement in youth ice hockey players

BACKGROUND

It has been reported that relative to other sports participants, ice hockey players suffer from cam-type femoroacetabular impingement (FAI) in higher numbers. α angles have been reported to increase with the likelihood of symptomatic FAI. It is unclear how prevalent increased α angles, commonly associated with cam FAI, are in asymptomatic young ice hockey players.

HYPOTHESIS

There would be a higher prevalence of α angles associated with cam FAI in youth ice hockey players than in a non-hockey-playing (skier) youth control group.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 61 asymptomatic youth ice hockey players (aged 10-18 years) and 27 youth skiers (controls) (aged 10-18 years) underwent a clinical hip examination consisting of the flexion/abduction/external rotation (FABER) distance test, impingement testing, and measurement of hip internal rotation. The hip α angle was measured by magnetic resonance imaging, and labral tears and articular cartilage lesions were documented. Hockey players were grouped according to their USA Hockey classification as peewees (ages 10-12 years), bantams (ages 13-15 years), and midgets (ages 16-19 years).

RESULTS

Overall, ice hockey players had significantly higher α angles than did the control group, and hockey players had a significant correlation between increased age and increased α angles, while the control group did not. In the ice hockey group, 75% had an α angle of ≥55°, while in the skier group, 42% had an α angle of ≥55° (P < .006). Hockey players were 4.5 times more likely to have an α angle commonly associated with cam impingement than skiers. Midget players had the highest risk of increased α angles.

CONCLUSION

Even at young ages, ice hockey players have a greater prevalence of α angles associated with cam FAI than do skier-matched controls. Properties inherent to ice hockey likely enhance the development of a bony overgrowth on the femoral neck, leading to cam FAI.

Preliminary evaluation of an MRI-based technique for displaying and quantifying bony deformities in cam-type femoroacetabular impingement

PURPOSE

Characterizing aspheric deformities of the femoral head-neck junction in cam-type femoroacetabular impingement (FAI) requires representing the location, size, or extent of the bony lesion. The objectives of this work are to (1) assess the feasibility of creating 3D models of cam deformities from MRI sets, (2) present a standardized 2D visualization of the lesion, and (3) present and evaluate the potential utility of summary metrics in distinguishing between FAI patients and control subjects.

METHODS

Using MRIs from five subjects with diagnosed cam-type FAI and four healthy subjects, we developed a technique based on subtracting an estimated normal surface from each subject's actual bone surface in order to generate a subject-specific 2D "diagnosis graph" that characterized the femoral deformity. The models from three control subjects were combined to create the baseline model.

RESULTS

The RMS fitting error between the surface models of individual control subjects and their corresponding baseline models was 1.05 mm across the head and the head-to-neck transition region. In the anterosuperior region of the 2D diagnosis graphs, the mean height of the detected cam deformities relative to the estimated baseline normal shape was 17.9 % of the head radius for the five FAI subjects (95 % CI 8.5-27.3 %) and 7.0 % (95 % CI 2.9-11.1 %) for the four control subjects. A binary logistic regression analysis indicated that an h/r ratio larger than a threshold of [Formula: see text] = 10.7 % (equivalent to approximately 2.3 mm in height) yielded the best discrimination between cam-type FAI subjects and normal subjects.

CONCLUSIONS

Our 2D diagnosis graph qualitatively enabled the cam-type lesions in four of our five diagnosed patients to be clearly visualized on MRI-derived models. We believe this visualization tool may be helpful in better characterizing cam-type lesions for diagnosis and for developing more precise plans for surgical treatment.

Growth plate alteration precedes cam-type deformity in elite basketball players

BACKGROUND

Vigorous sporting activity during the growth years is associated with an increased risk of having a cam-type deformity develop. The underlying cause of this osseous deformity is unclear. One may speculate whether this is caused by reactive bone apposition in the region of the anterosuperior head-neck junction or whether sports activity alters the shape of and growth in the growth plate. If the latter is true, then one would expect athletes to show an abnormal shape of the capital growth plate (specifically, the epiphyseal extension) before and/or after physeal closure.

QUESTIONS/PURPOSES

We therefore raised three questions: (1) Do adolescent basketball players show abnormal epiphyseal extension? (2) Does the epiphyseal extension differ before and after physeal closure? (3) Is abnormal epiphyseal extension associated with high alpha angles?

METHODS

We performed a case-control comparative analysis of young (age range, 9-22 years) male elite basketball athletes with age-matched nonathletes, substratified by whether they had open or closed physes. We measured epiphyseal extension on radial-sequence MRI cuts throughout the cranial hemisphere from 9 o'clock (posterior) to 3 o'clock (anterior). Epiphyseal extension was correlated to alpha angle measurements at the same points.

RESULTS

Epiphyseal extension was increased in all positions in the athletes compared with the control group. On average, athletes showed epiphyseal extension of 0.67 to 0.83 versus 0.53 to 0.71 in control subjects. In the control group epiphyseal extension was increased at all measurement points in hips after physeal closure compared with before physeal closure. In contrast, the subgroup of athletes with a closed growth plate only had increased epiphyseal extension at the 3 o'clock position compared with the athletes with an open [corrected] growth plate (0.64-0.70). We observed a correlation between an alpha angle greater than 55° and greater epiphyseal extension in the anterosuperior femoral head quadrant: the corresponding Spearman r values were 0.387 (all hips) and 0.285 (alpha angle>55°) for the aggregate anterosuperior quadrant.

CONCLUSIONS

These findings suggest that a cam-type abnormality in athletes is a consequence of an alteration of the growth plate rather than reactive bone formation. High-level sports activity during growth may be a new and distinct risk factor for a cam-type deformity.

Nonoperative treatment for femoroacetabular impingement: a systematic review of the literature

OBJECTIVE

Femoroacetabular impingement (FAI) has been identified as a common cause of hip pain in young adults. However, it is not known whether an effective nonoperative treatment exists and whether there is any evidence to support such a treatment. The purpose of this review is to establish whether nonoperative treatments exist for FAI in the published literature and whether there is any evidence to support their use. TYPE: A systematic review. LITERACY SURVEY: PubMed, Medline, EMBASE, CINAHL, AMED, and Cochrane Library databases were searched by using the following terms: femoroacetabular impingement, femoro-acetabular impingement, and hip impingement. The search was limited to English only but with no time constraints.

METHODOLOGY

The review was undertaken at 2 academic institutions within the United Kingdom; any article that described or provided evidence that related to a nonoperative treatment for FAI was included. Fifty-three articles met our criteria, of which, 48 were review and/or discussion based.

SYNTHESIS

Five articles summarized primary experiments that described or evaluated nonoperative treatment, of which, 3 reported favorable outcomes. Many review and/or discussion articles (31 [65%]) indicated that a trial of conservative care was appropriate. Activity modification was most frequently recommended (39 [81%]), and nearly half promoted physical therapy as a treatment (23 [48%]).

CONCLUSION

The review literature appears to promote initial nonoperative treatment for FAI. Although the available literature with experimental data is limited, there is a suggestion that physical therapy and activity modification confer some benefit to patients. Nonoperative treatment regimens, particularly physical therapy, need to be evaluated more extensively and rigorously, preferably against operative care, to determine the true clinical effectiveness.