Radiographic Femoroacetabular Impingement Research Articles

Increased asphericity of the femoral head-neck junction in professional breakers compared to hobby athletes – a retrospective case-control study

ABSTRACT Objective Breaking has gained public attention as a form of sports activity. The associated intense movements of the hip joints are possibly linked to the development of femoroacetabular impingement (FAI). Therefore, this study aimed to assess clinical and radiographic FAI measures in professional breakers compared to hobby athletes. Methods The study cohort consisted of professional breakers with persisting hip pain who were 1:1 matched to a cohort of FAI patients without professional sports careers from our outpatient clinic. The primary endpoint assessed on standardized plain radiographs was the alpha angle (AA). Further measures were the acetabular index (AI), lateral center-edge angle (LCEA), crossover sign, ischial spine sign, and femoral head extrusion index (FHEI). The modified Harris Hip Score (mHHS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score were used to obtain patient-reported measures. Results We recruited ten professional breakers and matched them to ten hobby athletes. The median AA was significantly higher in the breakers compared with the hobby athletes (73° [IQR 66.5°, 84.2°]) vs. 61.8° [IQR 59.5°, 64.8°], p = 0.0004). There was a significant reduction in weekly training hours in breakers after diagnosis (13.0 hours [interquartile range [IQR] 9.5, 32.4] to 1.5 hours [IQR 0, 4.8], p = 0.0039). There were no inter-group differences regarding mHHS, WOMAC, and additional radiographic measurements. Conclusion Breakers have higher AA in cam-type FAI compared to nonprofessional athletes. The corresponding hip pain significantly reduced training hours and caused the end of their breaking career. The potentially high prevalence of FAI in breakers and the corresponding consequences need to be considered early when athletes present with hip pain.

Differences in Kinematic Changes From Self-Selected to Fast Speed Gait in Asymptomatic Adults With Radiological Signs of Femoro-Acetabular Impingement.

Femoro-acetabular impingement (FAI) may present as alterations in the skeletal morphology of the hip. Repercussions of FAI can be witnessed in self-selected speed walking as well as physical exercise such as running or fast speed walking. The aim of this study was to investigate changes in kinematics at different gait speeds in subjects presenting with radiological findings invoking FAI. One hundred thirty asymptomatic adults underwent biplanar X-rays with a calculation of 3D hip parameters: acetabular anteversion, abduction and tilt, vertical center edge angle (VCE), femoral anteversion, neck-shaft angle, acetabular coverage of the femoral head, femoral head diameter and neck length. Parameters were classified according to FAI clinical thresholds. Two groups were created: Control group (63 subjects having up to one subnormal hip parameter in favour of FAI) and Radiographic FAI group (67 subjects having ≥2 subnormal hip parameters that might cause FAI). All subjects underwent 3D gait analysis at self-selected and fast speed, from which kinematic parameters were generated. Arithmetic differences between fast and self-selected speed gait were considered as gait changes. Subjects in the Radiographic FAI group had decreased acetabular tilt (24 vs. 19˚), anteversion (19 vs. 16˚), abduction (55 vs. 53˚), femoral anteversion (18 vs. 14˚) and increased VCE (29 vs. 33˚, all p<0.05), compared to controls.Changes from self-selected to fast speed showed that subjects in the Radiographic FAI group had lower range of motion (ROM) pelvic rotation (7 vs. 4˚) and ROM hip flexion/extension (10 vs. 7˚), reduced hip extension (-4 vs. -2˚) and step length (16 vs. 13 cm; all p<0.05). The Radiographic FAI group had decreased acetabular abduction, anteversion and femoral anteversion in favour of FAI. When adapting from self-selected to fast speed gait, the Radiographic FAI group seemed to limit pelvic rotation and hip flexion/extension resulting in a decrease in step length. These kinematic limitations were previously reported in subjects with symptomatic FAI. Gait analysis could be considered as a functional diagnostic tool to assess FAI along with radiological assessment.

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

BackgroundThe purpose of this pilot study was to validate the feasibility of a definitive study aimed at determining if high-intensity physical activity during adolescence impacts the development of femoroacetabular impingement (FAI).MethodsThis prospective cohort pilot study had a sample size target of 50 volunteers between 12 and 14 years old at sites in Canada, South Korea, and the Netherlands. Participants were evaluated clinically and radiographically at baseline and at 2 years. The participants’ sport and physical activity were evaluated using the Habitual Activity Estimation Scale (HAES) and the American Orthopaedic Society for Sports Medicine (AOSSM) criteria for sport specialization. The primary outcome was feasibility and secondary outcomes included the incidence of radiographic FAI and hip range of motion, function (Hip Outcome Score, HOS), and quality of life (Pediatric Quality of Life questionnaire, PedsQL) at 24 months. Study groups were defined at the completion of follow-up, given the changes in participant activity levels over time.ResultsOf the 54 participants enrolled, there were 36 (33% female) included in the final analysis. At baseline, those classified as highly active and played at least one organized sport had a higher incidence of asymptomatic radiographic FAI markers (from 6/32, 18.8% at baseline to 19/32, 59.4% at 24 months) compared to those classified as low activity (1/4, 25% maintained at baseline and 24 months). The incidence of radiographic FAI markers was higher among sport specialists (12/19, 63.2%) compared to non-sport specialists (8/17, 47.1%) at 24 months. The HOS and PedsQL scores were slightly higher (better) among those that were highly active and played a sport compared to those who did not at 2 years (mean difference (95% confidence interval): HOS-ADL subscale 4.56 (− 7.57, 16.70); HOS-Sport subscale 5.97 (− 6.91, 18.84); PedsQL Physical Function 7.42 (− 0.79, 15.64); PedsQL Psychosocial Health Summary 6.51 (− 5.75, 18.77)).ConclusionOur pilot study demonstrated some feasibility for a larger scale, definitive cohort study. The preliminary descriptive data suggest that adolescents engaged in higher levels of activity in sports may have a higher risk of developing asymptomatic hip deformities related to FAI but also better quality of life over the 2-year study period.

Arthroscopic Acetabular Labral Repair Versus Labral Debridement: Long-term Survivorship and Functional Outcomes.

Background:Arthroscopic treatment for labral tears includes debridement and repair. Long-term studies have failed to demonstrate a difference between these treatments in terms of conversion to total hip arthroplasty (THA).Purpose:To investigate 2 different labral treatments, debridement and repair, using an adjusted analysis to evaluate long-term conversion to THA.Study Design:Cohort study; Level of evidence, 3.Methods:This was a retrospective cohort study of patients who underwent hip arthroscopy by a single surgeon between April 2007 and October 2014. Postoperative follow-up information included conversion to THA, patient satisfaction, and patient-reported outcome measures (modified Harris Hip Score; Hip Outcome Score, Activities of Daily Living and Sports Specific subscales; International Hip Outcome Tool; Nonarthritic Hip Score; and Lower Extremity Functional Scale).Results:Of the 204 hips included in the study, 99 (48.5%) underwent labral repair, and 105 (51.5%) underwent debridement. In total, 28 (13.7%) of the 204 patients underwent conversion to THA within 10 years after hip arthroscopy (labral repair: 5 [5.0%] vs labral debridement: 23 [21.9%]). Labral repair was associated with a significantly lower risk of conversion to THA compared with debridement (hazard ratio [HR] = 0.24; 95% CI, 0.07-0.74; P = .014). Additional factors associated with risk of conversion to THA included older age at the time of arthroscopy (HR = 1.06 per year; 95% CI, 1.02-1.11; P = .002) and Tönnis grade (HR = 2.39; CI, 1.14-5.41; P = .026). Abrasion chondroplasty, acetabuloplasty, body mass index, Outerbridge grade, and radiographic femoroacetabular impingement were not found to be significantly associated with risk of THA. No significant difference in patient satisfaction was found between treatment groups, and for patients who did not convert to THA, there was no difference in mean patient-reported outcome scores at final follow-up.Conclusion:Patients who underwent labral repair were less likely to convert to THA compared with patients who underwent labral debridement, despite adjustment for differences in baseline patient characteristics and preexisting pathology. Additional factors associated with a lower rate of hip survival were older age and osteoarthritis at the time of hip arthroscopy.

Characterizing femoroacetabular impingement in professional Nordic Skiers

ABSTRACT 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.

Treatment of Full-Thickness Acetabular Chondral Flaps During Hip Arthroscopy: Bone Marrow Aspirate Concentrate Versus Microfracture.

Background:The optimal treatment strategy for patients with full-thickness chondral flaps undergoing hip arthroscopy is controversial.Purpose:To compare functional outcomes of patients who underwent bone marrow aspirate concentrate (BMAC) application with those of patients who underwent microfracture.Study Design:Cohort study; Level of evidence, 3.Methods:This was a retrospective case series of prospectively collected data on patients who underwent arthroscopic acetabular labral repair by 1 surgeon between June 2014 and April 2020. The inclusion criteria for this study were age ≥18 years, preoperative radiographs of the pelvis, arthroscopic acetabular labral repair, exposed subchondral bone with overlying chondral flap seen at the time of hip arthroscopy, microfracture or BMAC to address this lesion, and completed patient-reported outcome measures (PROMs) (International Hip Outcome Tool–33 [iHOT-33], Hip Outcome Score–Activities of Daily Living [HOS-ADL], Hip Outcome Score–Sports Subscale [HOS-Sport], modified Harris Hip Score [mHHS], and visual analog scale [VAS] for pain) at enrollment and 12-month follow-up. Clinical outcomes were assessed using PROM scores.Results:A total of 81 hips with full-thickness chondral flaps were included in this study: 50 treated with BMAC and 31 treated with microfracture. There were no significant differences between groups in age, sex, body mass index, tear size, radiographic osteoarthritis, or radiographic femoroacetabular impingement. In the BMAC cohort, all PROM scores improved significantly from preoperatively to follow-up: 41.7 to 75.6 for iHOT-33, 67.6 to 91.0 for HOS-ADL, 41.5 to 72.3 for HOS-Sport, 59.4 to 87.2 for mHHS, and 6.2 to 2.2 for VAS pain (P < .001 for all). In the microfracture cohort, the score improvements were 48.0 to 65.1 for iHOT-33 (P = .001), 80.5 to 83.3 for HOS-ADL (P = .275), 59.2 to 62.4 for HOS-Sport (P = .568), 70.4 to 78.3 for mHHS (P = .028), and 4.9 to 3.6 for VAS pain (P = .036). Regarding clinically meaningful outcomes, 77.6% of the BMAC group and 50.0% of the microfracture group met the minimal clinically important difference for iHOT-33 at the 12-month follow-up (P = .013).Conclusion:Patients with full-thickness chondral flaps at the time of hip arthroscopy experienced greater improvements in functional outcome scores at the 12-month follow-up when treated with BMAC as opposed to microfracture.

Sex differences in the prevalence of radiographic findings of structural hip deformities in patients with symptomatic femoroacetabular impingement.

ABSTRACTThe purpose of this study was to determine the sex differences in the overall prevalence of radiographic femoroacetabular impingement (FAI) deformity patients presenting with hip pain and to identify the most common radiographic findings in male and female patients. A geographic database was used to identify patients between the age of 14 and 50 years with hip pain from 2000 to 2016. A chart and radiographic review was performed to identify patients with cam, pincer and mixed-type FAI. A total of 374 (449 hips) out of 612 (695 hips) male patients and 771 (922 hips) out of 1281 (1447 hips) female patients had radiographic features consistent with FAI. Ninety-four male hips (20.9%) and 45 female hips (4.9%) had cam type, 20 male hips (4.5%) and 225 female hips (24.4%) had pincer type and 335 male hips (74.6%) and 652 female hips (70.7%) had mixed type. The overall prevalence of radiographic findings consistent with FAI in male and female patients with hip pain was 61.1% and 60.2%, respectively. Mixed type was the most prevalent. The most common radiographic finding for cam-type FAI was an alpha angle >55°, and the most common radiographic finding for pincer-type FAI was a crossover sign. Male patients were found to have a higher prevalence of cam-type deformities, whereas female patients were found to have a higher prevalence of pincer-type deformities.

Incidence of radiographic findings of femoroacetabular impingement in a healthy Egyptian population: a cross-sectional study

Background: Femoroacetabular impingement (FAI) is a unique pathological problem affecting young adults. It can be defined as the impingement between the proximal femur and the acetabular rim. Although clinical presentation usually is hip pain, it can be asymptomatic. Radiographic FAI findings are quite common in a population of healthy young adults and must be correlated to the clinical presentation. The aim of our study was to evaluate the incidence of radiographic findings of FAI among a cohort of healthy Egyptian participants. Methods: From March 2017 to April 2019, a cross-sectional study was conducted among a cohort of 160 Egyptians (100 men and 60 women) from 20 to 40 yr old. Anteroposterior and frog-leg lateral views were obtained for 320 hips. By using computer software (ICONICO Screen Protractor, ICONICO, Inc., New York, NY), we measured central edge crossover sign alpha angle and the acetabular index. Results: Pincer type FAI was found in 86 hips on the right side (53.27%) and in 104 hips on the left side (65%). Cam type of FAI was found in 54 hips on the right side (34.2%) and in 54 hips on the left side (34.2%). Mixed type was found in 26 hips on the right side (16.25%) and in 32 hips on the left side (20%). Conclusions: Radiographic FAI findings are quite common in Egyptian healthy young adults who have no hip symptoms. Clinical diagnosis is necessary for FAI and must be correlated with the radiographic data. Level of Evidence: Level II.

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

ABSTRACT 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.

A Unique and Characteristic Cam FAI Morphology in Young Patients with Comorbid Inflammatory Conditions.

The relationship between femoroacetabular impingement (FAI) and inflammatory medical comorbidities has not been established in the pediatric population. The purpose of this study was to investigate the prevalence of inflammatory conditions in pediatric patients with FAI and the morphology of the associated deformity. We performed a retrospective cohort study of 90 patients who were diagnosed with FAI in our institution's adolescent hip clinic from January 2016 to March 2018. Patients with an inflammatory comorbidity were identified. Standard quantitative radiographic FAI measurements as well as qualitative femoral head-neck junction morphology were analyzed. Eight patients (8.9%) with 11 symptomatic hips were found to have an inflammatory condition. These 8 patients all had cam deformities. Nine of the symptomatic hips in this subset of patients had a negative femoral offset, where the cam deformity extended beyond the anterior margin of the femoral head. Qualitative assessment revealed a unique head-neck morphology with a prominent and "sharp-edged" bump at the head-neck junction, which resembled an inflammatory beak. In comparing patients with and without inflammatory comorbidities, a marked difference was found for alpha angles (difference, 26.6°; 95% confidence interval [CI], 18.2° to 35.0°) but not for age at diagnosis (difference, 0.5 years; 95% CI, -0.8 to 1.6 years) or the lateral center-edge angle (difference, 1.9°; 95% CI, -3.9° to 7.7°). At our institution, 8.9% of pediatric patients with FAI were found to have an inflammatory comorbidity. These patients presented with a characteristic prominent "sharp-edged" head-neck morphology that standard radiographic measurements captured as a negative femoral offset and a larger alpha angle than was seen in patients without systemic inflammatory disease. Awareness of the characteristic cam deformity that was found in these patients may help to identify patients with undiagnosed inflammatory conditions. This unique deformity also raises questions regarding the possible role of physeal inflammation in the development of cam deformities and indicates a need for additional studies to investigate the relationship between systemic inflammatory diseases and FAI. Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Characterizing the Prevalence of Cam-Type Hip Impingement in Professional Women’s Ice Hockey Players

BackgroundRecent studies have demonstrated a high prevalence of femoroacetabular impingement (FAI) in elite men’s ice hockey players, yet little is known about the hips of elite women’s ice hockey players.PurposeThe primary purpose of this study was to determine the prevalence of radiographic cam-type FAI in professional women’s ice hockey players in the National Women’s Hockey League (NWHL). The secondary purpose was to analyze the relationship between the presence of cam deformity and both hip range-of-motion (ROM) and age of menarche.MethodsClinical, radiographic and demographic data were collected during player pre-participation physicals. ROM measurements were performed with a goniometer. Alpha angles were measured on 45° Dunn radiographs, with alpha angles >55° defined as cam-positive (Figure 1). Measurements were performed 3 separate times by 4 investigators. One-way ANOVA, independent means t-test and Pearson correlation coefficients were calculated, with statistical significance set at p<0.05.ResultsTwenty-six female athletes were included. Average menarchal age was 13.8 ±1.5 years. 24 (92%) had alpha angles >55°; 20 (77%) had bilateral cam deformity. Inter-rater reliability was excellent at 0.86. Intra-rater reliability was also excellent, with mean ICC=0.87 (range= 0.82-0.90 for each rater). There was a significant positive association between age of menarche and alpha angle (p<0.02, Figure 2). There was no association between alpha angle and hip ROM.ConclusionElite female ice hockey players have a higher prevalence of cam morphology than the general population. The positive association between alpha angle and age of menarche supports the etiological hypothesis of the cam lesion resulting from activity-related stress at the proximal femoral physis during a period of physiologic vulnerability. Professional women’s ice hockey players have a high risk of developing cam morphology of the proximal femur, although each player’s age of menarche may mediate her individual risk for cam lesion development.Figure 1.Figure 2.

The Prevalence of Radiographic Findings of Structural Hip Deformities for Femoroacetabular Impingement in Patients With Hip Pain

Background: Radiography is the initial imaging modality used to evaluate femoroacetabular impingement (FAI), and diagnostic radiographic findings are well-established. However, the prevalence of these radiographic findings in patients with hip pain is unknown. Purpose: The purpose was 3-fold: (1) to determine the overall prevalence of radiographic FAI deformities in young patients presenting with hip pain, (2) to identify the most common radiographic findings in patients with cam-type FAI, and (3) to identify the most common radiographic findings in patients with pincer-type FAI. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A geographic database was used to identify patients aged 14 to 50 years with hip pain between the years 2000 to 2016. The following were evaluated on radiographs: cam type: typical pistol grip deformity, alpha angle >55°; pincer type: crossover sign (COS), coxa profunda or protrusio acetabuli, lateral center edge angle (LCEA) ≥40°, Tönnis angle <0°; and mixed type: both cam- and pincer-type features. Posterior wall sign (PWS) and ischial spine sign (ISS) were also evaluated. The prevalence of each was determined. Descriptive statistics were performed on all radiographic variables. Results: There were 1893 patients evaluated, and 1145 patients (60.5%; 1371 hips; 374 male and 771 female; mean age, 28.8 ± 8.4 years) had radiographic findings consistent with FAI. Of these hips, 139 (10.1%) had cam type, 245 (17.9%) had pincer type, and 987 (72.0%) had mixed type. The prevalence of a pistol grip deformity and an alpha angle >55° was 577 (42.1%) and 1069 (78.0%), respectively. The mean alpha angle was 66.9°± 10.5°. The prevalence of pincer-type radiographic findings was the following: COS, 1062 (77.5%); coxa profunda, 844 (61.6%); ISS, 765 (55.8%); PWS, 764 (55.7%); Tönnis angle <0°, 312 (22.8%); LCEA ≥40°, 170 (12.4%); and protrusio acetabuli, 7 (0.5%). Conclusion: The overall prevalence of radiographic findings consistent with FAI in young patients with hip pain was 60.5%. Radiographic findings for mixed-type FAI were the most prevalent. The most common radiographic finding for cam-type FAI was an alpha angle >55°. The most common radiographic finding for pincer-type FAI was the COS.

Results of hip arthroscopy in elite level water polo players with femoroacetabular impingement: return to play and patient satisfaction.

Water polo places significant stress on the hip joint requiring repetitive hip flexion and rotation to elevate the body out of water for passing, shooting and blocking. Femoroacetabular impingement (FAI) is common in water polo athletes; however, no study to date has investigated the results of hip arthroscopy in this patient population. The purpose of this study was to determine return to play rates and satisfaction following hip arthroscopy for FAI in a cohort of elite level water polo players. A retrospective review of our surgical database was performed. Collegiate water polo players with clinical and radiographic FAI who underwent hip arthroscopy were identified. Pre- and post-operative modified Harris hip scores (mHHSs) were obtained. Patient surveys were administered to determine return to play rates, level of return to play, timing of return and patient satisfaction. A Wilcoxon ranked sum test was performed to compare pre- and post-operative outcome scores. Ten patients met inclusion criteria. Average age was 19.5 years old (SD ±1.08). All patients were male Division 1 collegiate water polo players. Median mHHS improved from 66.0 (SD ±7.9) pre-operatively to 89.5 (SD ±3.2) at average 1.6 years (range: 0.4–3.6 years) post-operatively. Patient survey responses demonstrated a 100% return to water polo and 100% return to the same level of play (NCAA Division 1) at mean 5.75 months (SD ±1.8). All patients (10/10) reported being satisfied with their surgical result. Our study results, suggest that return to sport rates and patient satisfaction are high in water polo players who undergo hip arthroscopy for FAI.

Characterizing the Prevalence of Cam-Type Hip Impingement in Women’s Professional Ice Hockey Players

Objectives:Participation rates in women’s ice hockey is increasing in North America. Recent studies have demonstrated an increased prevalence of femoroacetabular impingement (FAI) in elite male ice hockey players, yet little is known about hip pathology of players in the National Women’s Hockey League (NWHL). The primary purpose of this study was to determine the prevalence of radiographic FAI in women’s professional ice hockey players. The secondary purpose was to analyze the relationship between the presence of radiographic cam deformity and hip ROM, clinical impingement signs and age of menarche.Methods:In this IRB-approved study, physical examination and demographic data were prospectively collected for 27 NWHL players. Alpha angles were measured on 45-degree Dunn views with an alpha angle >55° defined as cam-positive. Pearson correlations were performed to analyze the relationship between alpha angle and ROM measurements, clinical impingement signs and self-reported age of menarche. Players were grouped into those with and without cam impingement and group differences were assessed using the student’s t-test. Statistical significance was set at p<0.05.Results:Twenty-seven athletes were included in the study. Nineteen of the 27 players (70%) had radiologic evidence of cam-type impingement with alpha angle >55 degrees; 14 players (52%) had bilateral cam deformity. The average age of menarche was 13.9±1.5 years. There was a significant association between age of menarche and right alpha angle (R=0.57, CI [0.16, 0.81], p=0.011), as well as age of menarche and left alpha angle (R=0.48, CI [0.03, 0.77], p=0.039). There was no statistically significant association between alpha angle and any ROM measurement. Additionally, there was no difference in the incidence of clinical impingement for players with or without an alpha angle >55°.Conclusion:This study suggests that elite female ice hockey players have a significantly higher prevalence of cam-type morphology than the general population. The clinical significance of this radiographic finding is uncertain as the majority of these deformities seem to be asymptomatic. Interestingly, the positive association between alpha angle and age of menarche lends support to the etiological hypothesis that cam lesions are a result of activity-related stress at the proximal femoral physis. This data suggests that players with earlier menarche (and therefore earlier physeal closure) seem to be less vulnerable to the development of cam deformity of the proximal femur.

Lisa S. Krivickas Clinician/Scholar Travel Award: Characterizing the Prevalence of Cam-Type Hip Impingement in Women’s Professional Ice Hockey Players

PURPOSE Recent studies have demonstrated an increased prevalence of femoroacetabular impingement (FAI) in 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 presence of cam deformity and hip ROM; clinical impingement signs; and age of menarche. METHODS Clinical, radiographic and demographic 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. Spearman correlations were performed to analyze the relationship between alpha angle and both ROM measurements and menarchal age. Players were grouped into those with and without cam lesions and group differences were assessed using the student's t-test. RESULTS Twenty-seven athletes were included. Nineteen (70%) had alpha angles >55°; 14 (52%) had bilateral cam deformity. Average menarchal age was 13.9 ±1.5 years. There was a significant association between age of menarche and alpha angle (right hips, p=0.01; left hips, p=0.04). There was no significant association between alpha angle and either hip ROM or clinical impingement signs. CONCLUSION This study suggests that elite female ice hockey players have a higher prevalence of cam-type morphology than the general population. The positive association between alpha angle and age of menarche lends additional support to the etiological hypothesis of the cam lesion resulting from activity-related stress at the proximal femoral physis; players with earlier menarche (and therefore earlier physeal closure) seem to be less vulnerable to the development of cam deformity of the proximal femur. Thus, professional women’s ice hockey players have a high risk of developing cam-type morphology of the proximal femur, although each player’s age of menarche may mediate her individual risk for cam lesion development.

Characterizing the Prevalence of Cam-Type Hip Impingement in Women’s Professional Ice Hockey Players

PURPOSE: Recent studies have demonstrated an increased prevalence of femoroacetabular impingement (FAI) in 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 presence of cam deformity and hip ROM; clinical impingement signs; and age of menarche. METHODS: Clinical, radiographic and demographic 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. Spearman correlations were performed to analyze the relationship between alpha angle and both ROM measurements and menarchal age. Players were grouped into those with and without cam lesions and group differences were assessed using the student's t-test. RESULTS: Twenty-seven athletes were included. Nineteen (70%) had alpha angles >55°; 14 (52%) had bilateral cam deformity. Average menarchal age was 13.9 ±1.5 years. There was a significant association between age of menarche and alpha angle (right hips, p=0.01; left hips, p=0.04). There was no significant association between alpha angle and either hip ROM or clinical impingement signs. CONCLUSION: This study suggests that elite female ice hockey players have a higher prevalence of cam-type morphology than the general population. The positive association between alpha angle and age of menarche lends additional support to the etiological hypothesis of the cam lesion resulting from activity-related stress at the proximal femoral physis; players with earlier menarche (and therefore earlier physeal closure) seem to be less vulnerable to the development of cam deformity of the proximal femur. Thus, professional women’s ice hockey players have a high risk of developing cam-type morphology of the proximal femur, although each player’s age of menarche may mediate her individual risk for cam lesion development.

Nonoperative Management of Femoroacetabular Impingement: A Prospective Study

Background: The literature has given little attention to the nonoperative management of femoroacetabular impingement (FAI) syndrome despite a rapidly expanding body of research on the topic. Purpose: To perform a prospective study utilizing a nonoperative protocol on a consecutive series of patients presenting to our clinic with FAI syndrome. Study Design: Cohort study; Level of evidence, 2. Methods: Between 2013 and 2016, patients meeting the following criteria were prospectively recruited in a nonoperative FAI study: no prior hip surgery, groin-based pain, a positive impingement test, and radiographic FAI syndrome. The protocol consisted of an initial trial of rest, physical therapy, and activity modification. Patients who remained symptomatic were then offered an image-guided intra-articular steroid injection. Patients with recurrent symptoms were then offered arthroscopic treatment. Outcome scores were collected at 12 and 24 months. Statistical analysis was performed to identify risk factors for the need for operative treatment and to determine patient outcomes based on FAI type and treatment. Results: Ninety-three hips (n = 76 patients: mean age, 15.3 years; range, 10.4-21.4 years) were included in this study and followed for a mean ± SD 26.8 ± 8.3 months. Sixty-five hips (70%) were managed with physical therapy, rest, and activity modification alone. Eleven hips (12%) required a steroid injection but did not progress to surgery. Seventeen hips (18%) required arthroscopic management. All 3 groups saw similar improvements in modified Harris Hip Score (P = .961) and nonarthritic hip score (P = .975) with mean improvements of 20.3 ± 16.8 and 13.2 ± 15.5, respectively. Hips with cam impingement and combined cam-pincer impingement were 4.0 times more likely to meet the minimal clinically important difference in modified Harris Hip Score (P = .004) and 4.4 times more likely to receive surgical intervention (P = .05) than patients with pincer deformities alone. Participants in team sports were 3.0 times more likely than individual sport athletes to return to competitive activities (P = .045). Conclusion: A majority (82%) of adolescent patients presenting with FAI syndrome can be managed nonoperatively, with significant improvements in outcome scores at a mean follow-up of 2 years. Clinical Relevance: A nonoperative approach should be the first-line treatment for young active patients with symptomatic FAI syndrome.

The role of lumbar lordosis and pelvic sagittal balance in femoroacetabular impingement.

The purpose of this study was to evaluate spinopelvic mechanics from standing and sitting positions in subjects with and without femoroacetabular impingement (FAI). We hypothesize that FAI patients will experience less flexion at the lumbar spine and more flexion at the hip whilst changing from standing to sitting positions than subjects without FAI. This increase in hip flexion may contribute to symptomatology in FAI. Male subjects were prospectively enrolled to the study (n = 20). Mean age was 31 years old (22 to 41). All underwent clinical examination, plain radiographs, and dynamic imaging using EOS. Subjects were categorized into three groups: non-FAI (no radiographic or clinical FAI or pain), asymptomatic FAI (radiographic and clinical FAI but no pain), and symptomatic FAI (patients with both pain and radiographic FAI). FAI was defined as internal rotation less than 15° and alpha angle greater than 60°. Subjects underwent standing and sitting radiographs in order to measure spine and femoroacetabular flexion. Compared with non-FAI controls, symptomatic patients with FAI had less flexion at the spine (mean 22°, sd 12°, vs mean 35°, sd 8°; p = 0.04) and more at the hip (mean 72°, sd 6°, vs mean 62°, sd 8°; p = 0.047). Subjects with asymptomatic FAI had more spine flexion and similar hip flexion when compared to symptomatic FAI patients. Both FAI groups also sat with more anterior pelvic tilt than control patients. There were no differences in standing alignment among groups. Symptomatic patients with FAI require more flexion at the hip to achieve sitting position due to their inability to compensate through the lumbar spine. With limited spine flexion, FAI patients sit with more anterior pelvic tilt, which may lead to impingement between the acetabulum and proximal femur. Differences in spinopelvic mechanics between FAI and non-FAI patients may contribute to the progression of FAI symptoms. Cite this article: Bone Joint J 2018;100-B:1275-9.

Trunk and lower limb biomechanics during stair climbing in people with and without symptomatic femoroacetabular impingement

BackgroundFemoroacetabular impingement is a pathomechanical hip condition leading to pain and impaired physical function. It has been shown that those with femoroacetabular impingement exhibit altered gait characteristics during level walking and stair climbing, and decreased muscle force production during isometric muscle contractions. However, no studies to-date have looked at trunk kinematics or muscle activation during dynamic movements such as stair climbing in this patient population. The purpose of this study was to compare biomechanical outcomes (trunk and lower limb kinematics as well as lower limb kinetics and muscle activation) during stair climbing in those with and without symptomatic femoroacetabular impingement. MethodsTrunk, hip, knee and ankle kinematics, as well as hip, knee and ankle kinetics and muscle activity of nine lower limb muscles were collected during stair climbing for 20 people with clinical and radiographic femoroacetabular impingement and compared to 20 age- and sex-matched pain-free individuals. FindingsThose with femoroacetabular impingement ascended the stairs slower (effect size=0.82), had significantly increased peak trunk forward flexion angles (effect size=0.99) and external hip flexion moments (effect size=0.94) and had decreased peak external knee flexion moments (effect size=0.90) compared to the control group. InterpretationFindings from this study indicate that while those with and without femoroacetabular impingement exhibit many biomechanical similarities when ascending stairs, differences in trunk forward flexion and joint kinetics indicate some important differences. Further longitudinal research is required to elucidate the cause of these differences as well as the clinical relevance.

CT-based morphological assessment of the hip joint in Japanese patients: association with radiographic predictors of femoroacetabular impingement.

Femoroacetabular impingement (FAI) has been highlighted and well documented primarily in Western countries and there are few large studies focused on FAI-related morphological assessment in Asian patients. We chose to investigate this subject. We assessed the morphology of the hip and the prevalence of radiographic FAI in Japanese patients by measuring predictors of FAI. We reviewed a total of 1178 hips in 695 men and 483 women with a mean age of 58.2 years (20 to 89) using CT images that had been obtained for reasons unrelated to symptoms from the hip. We measured the lateral centre edge angle, acetabular index, crossover sign, alpha angle and anterior femoral head-neck offset ratio. A total of 441 hips (37.4%) had pincer-type deformity (41.7% men, 31.3% women) and 534 (45.3%) had cam-type deformity (54.4% men, 32.3% women). Moreover, 773 hips (65.6%) had at least one parameter that predisposes to FAI (74.0% men, 53.6% women) and 424 hips (36.0%) had two or more parameters (43.6% men, 25.0% women). The prevalence of radiographic FAI was common in Japanese patients who are generally considered to have dysplastic hips. Cite this article: Bone Joint J 2016;98-B:1167-74.