Is the cam lesion (alpha angle) size related to symptoms and impairments in people with symptomatic femoroacetabular impingement?

Background: Radiographic findings related to the cam and pincer variants of femoroacetabular impingement (FAI) include measurements of the alpha angle and lateral center-edge angle (LCEA). The function of these radiographic findings has been put into question because of high heterogeneity in reported studies. Purpose: The aim of this study was 3-fold: (1) to determine the prevalence of cam and pincer variants according to sex and age on anteroposterior (AP) pelvic radiographs from an asymptomatic nonathletic population, (2) to identify the most common radiographic signs of cam- and pincer-type variants, and (3) to determine if there are variations in the prevalence of these radiographic signs according to sex and age. Study Design: Cross-sectional study; Level of evidence, 3. Methods: There were 3 independent observers who retrospectively analyzed the 939 AP pelvic radiographs (1878 hips) of patients aged 18 to 50 years who did not have hip symptoms and who were not professional athletes. The prevalence of the cam and pincer variants according to the alpha angle and LCEA, respectively, and the presence of other radiographic signs commonly associated with these variables were determined in the overall population and by subgroup according to sex and age group (18-30, 31-40, and 41-50 years). Descriptive and inferential statistics were used to analyze the study sample. Results: The mean age of the included population was 31.0 ± 9.2 years, and 68.2% were male. The prevalence of the cam-type variant was 29.7% (558/1878), and that of the pincer-type variant was 24.3% (456/1878). The radiographic signs that were most associated with the cam and pincer variants were a pistol-grip deformity and the crossover sign, respectively. Significant differences ( P < .001) in the prevalence of these variants were identified between men and women in both variants. No differences were observed in the alpha angle or LCEA according to sex or age. Conclusion: Radiographic findings suggestive of FAI had significant variations with respect to sex and age in this study sample. This study provides information to determine the prevalence of these anatomic variants in the general population.

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

Sports Health A Multidisciplinary Approach ◽

10.1177/1941738120973662 ◽

2021 ◽

pp. 194173812097366

Author(s):

André Orlandi Bento ◽

Guilherme Falótico ◽

Keelan Enseki ◽

Ronaldo Alves Cunha ◽

Benno Ejnisman ◽

...

Keyword(s):

Femoroacetabular Impingement ◽

Lower Limb ◽

Clinical Relevance ◽

Morphological Changes ◽

Alpha Angle ◽

Soccer Players ◽

Level Of Evidence ◽

Rotational Movement ◽

Professional Soccer ◽

Significant Difference

Background: Morphological changes characteristic of femoroacetabular impingement (FAI) are common in soccer players. However, the clinical relevance of such anatomical variations is still not well-defined. Hypothesis: We hypothesized that high alpha angle values and/or acetabular retroversion index (ARI) are correlated with rotational range of motion (ROM) of the hip and that there are clinical-radiological diferences between the dominant lower limb (DLL) and nondominant lower limb (NDLL) in professional soccer players. Study Design: Cross-sectional. Level of Evidence: Level 3. Methods: A total of 59 male professional soccer players (average age 25.5 years, range 18-38 years) were evaluated in the preseason. As main outcome measures, we evaluated the alpha angle and the ARI and hip IR and ER ROM with radiographic analysis. Results: The measurements taken on DLL and NDLL were compared and a significant difference was found between the sides in the ER ( P = 0.027), where the DLL measures were 1.54° (95% CI, 0.18-2.89) greater than the NDLL. There were no significant differences between the sides in the measures of IR ( P > 0.99), total ROM ( P = 0.07), alpha angle ( P = 0.250), and ARI ( P = 0.079). The correlations between the rotation measurements and the alpha angle in each limb were evaluated and the coefficient values showed no correlation; so also between the ARI and rotation measures. Conclusion: Morphological changes of the femur or acetabulum are not correlated with hip IR and ER ROM in male professional soccer players. ER on the dominant side was greater than on the nondominant side. There was no significant difference in the other measurements between sides. Clinical Relevance: In clinical practice, it is common to attribute loss of hip rotational movement to the presence of FAI. This study shows that anatomical FAI may not have a very strong influence on available hip rotational movement in professional soccer athletes.

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IDENTIFICATION OF FACTORS ASSOCIATED WITH DISEASE PROGRESSION IN THE CONTRALATERAL HIP OF PATIENTS WITH SYMPTOMATIC FEMOROACETABULAR IMPINGEMENT

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967121s00145 ◽

2021 ◽

Vol 9 (7_suppl3) ◽

pp. 2325967121S0014

Author(s):

Adam Khan ◽

Craig R. Louer ◽

Wahid Abu-Amer ◽

Gail Pashos ◽

Cecilia Pascual Garrido ◽

...

Keyword(s):

Disease Progression ◽

Femoroacetabular Impingement ◽

External Rotation ◽

Univariate Analysis ◽

Alpha Angle ◽

Hip Osteoarthritis ◽

Symptom Development ◽

Ucla Activity Score ◽

Center Edge ◽

Imaging Characteristics

Introduction: Femoroacetabular Impingement (FAI) is one of the most common causes of hip osteoarthritis. Nevertheless, the factors contributing to symptom development and FAI disease progression are poorly understood. Hypothesis/Purpose: The purpose of this study was to (1) investigate rates of initial and subsequent symptom development in the contralateral hip of patients with FAI, and (2) identify predictors of disease progression (symptom development) in the contralateral hip. Methods: This prospective study included a minimum 5 year follow-up of the contralateral hip in 179 patients undergoing FAI surgery. Symptoms (moderate pain) were monitored over the study course. Univariate analysis compared patient and FAI imaging characteristics of patients developing symptoms to those who remained asymptomatic. Results: 146 patients (146 hips, 81.5%) were included (min 5 year, mean 6.7 years). Thirty-nine (26%) presented with symptoms in the contralateral hip while 34 (23%) developed symptoms. Head-neck offset ratio (HNOR) on AP pelvis radiographs was significantly lower among hips that developed symptoms (0.164 vs. 0.153 p=0.025). Maximum alpha angle (p=0.413), lateral center edge angle (p=0.704), and crossover sign (p=0.115) were not predictive of symptoms. Patients with a UCLA activity score greater than 9 were less likely to develop symptoms (14% vs. 46%, p=0.081), but this was not statistically significant. The total arc of rotation in extension (35.740 vs 45.140, p=0.012) and 900 of flexion (40.00 vs 50.800, p=0.009) as well as external rotation at 900 of flexion (28.940 vs 36.590, p=0.020) were decreased in hips developing symptoms. Internal Rotation in flexion was not significantly decreased in symptomatic patients (11.060 vs 14.20, p=0.113). Conclusions: We identified unique radiographic and physical exam findings that are associated with symptom development in patients with FAI. Specifically, decreased hip rotation arc and decreased HNOR were strongly associated with disease progression and may represent important factors for future risk modeling in FAI patients.

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

The American Journal of Sports Medicine ◽

10.1177/0363546519896355 ◽

2020 ◽

Vol 48 (3) ◽

pp. 647-653 ◽

Cited By ~ 1

Author(s):

Jun Zhou ◽

Heath P. Melugin ◽

Rena F. Hale ◽

Devin P. Leland ◽

Christopher D. Bernard ◽

...

Keyword(s):

Femoroacetabular Impingement ◽

Mixed Type ◽

Imaging Modality ◽

Alpha Angle ◽

Young Patients ◽

Radiographic Finding ◽

Hip Pain ◽

Radiographic Findings ◽

Protrusio Acetabuli ◽

Center Edge

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.

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Proximal Alpha Angle Persists Abnormal in Patients with a Residual Bony Prominence after Surgery for Femoroacetabular Impingement

Arthroscopy The Journal of Arthroscopic and Related Surgery ◽

10.1016/j.arthro.2013.09.021 ◽

2013 ◽

Vol 29 (12) ◽

pp. e191-e192

Author(s):

Luis Moya ◽

Ignacio Villalon ◽

Claudio Mella ◽

Joaquin Lara

Keyword(s):

Femoroacetabular Impingement ◽

Alpha Angle ◽

Bony Prominence

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Treatment of cam-type femoroacetabular impingement

Joints ◽

10.11138/jts/2015.3.2.067 ◽

2015 ◽

Vol 03 (02) ◽

pp. 67-71 ◽

Cited By ~ 5

Author(s):

Gennaro Fiorentino ◽

Alberto Fontanarosa ◽

Riccardo Cepparulo ◽

Alberto Guardoli ◽

Luca Berni ◽

...

Keyword(s):

Femoroacetabular Impingement ◽

Hip Arthroscopy ◽

Alpha Angle ◽

Case Series ◽

Arthroscopic Treatment ◽

Correct Selection ◽

Harris Hip Score ◽

Radiographic Examination ◽

Level Of Evidence

Purpose: the aim of this study was to evaluate preliminary clinical and radiographic results of arthroscopic treatment of cam-type femoroacetabular impingement (FAI). Methods: thirty-eight patients underwent hip arthroscopy for cam-type FAI between 2009 and 2012. Preoperative assessment was based on clinical examination, modified Harris Hip Score (mHHS) and radiographic examination with anteroposterior pelvis, frogleg and Lequesne views. The patients’ clinical conditions at follow-up were assessed using the mHHS administered as a telephone survey. Radiographic outcome measurements evaluated pre and postoperatively were the alpha angle and femoral head-neck offset. Results: the patients were clinically evaluated at a mean follow-up of 36 months. Radiographic follow-up was performed at an average of 12.7 months. Thirty of the 38 patients (79%) were satisfied with the results of the arthroscopic procedure. A total of nine patients subsequently underwent a total hip replacement. All 30 patients who declared themselves satisfied recorded an mHHS increase; in particular, the mHHS increased from a mean of 52.9 preoperatively (range: 27.5-82.5) to a mean of 85.6 postoperatively (range: 45.1-100.1). Three significant differences between the two groups of patients (satisfied and not satisfied) were recorded: mean age, alpha angle and BMI were all significantly greater in the patients who were not satisfied with the treatment. Conclusions: a crucial aspect in order to obtain good clinical outcomes of arthroscopic treatment of camtype impingement is correct selection of patients who are likely to benefit from this kind of surgery. Hip arthroscopy should be avoided in patients aged over 50 years with risk factors for early osteoarthritis (high BMI and a significantly increased alpha angle). Level of evidence: Level IV, therapeutic case series.

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Defining Meaningful Functional Improvement on the Visual Analog Scale for Satisfaction at 2-years After Hip Arthroscopy for Femoroacetabular Impingement Syndrome

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967120s00439 ◽

2020 ◽

Vol 8 (7_suppl6) ◽

pp. 2325967120S0043

Author(s):

Edward Beck ◽

Benedict Nwachukwu ◽

Nabil Mehta ◽

Kyleen Jan ◽

Kelechi Okoroha ◽

...

Keyword(s):

Visual Analog Scale ◽

Femoroacetabular Impingement ◽

Hip Arthroscopy ◽

Alpha Angle ◽

Impingement Syndrome ◽

Analog Scale ◽

Important Improvement ◽

Femoroacetabular Impingement Syndrome ◽

Clinically Significant ◽

Preoperative Predictors

Objectives: Patient satisfaction is being increasingly reported in orthopaedic sports medicine and the field of hip preservation surgery. The Visual Analog Scale (VAS) for Satisfaction is most commonly utilized. Currently there is limited understanding for what should be considered as clinically important improvement on the VAS Satisfaction. The purpose of this study is to 1) define Substantial Clinical Benefit (SCB), Patient Acceptable Symptomatic State (PASS), and Minimal Clinically Important Difference (MCID) for the VAS Satisfaction in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS), and 2) identify preoperative predictors of achieving each outcome end-point. Methods: Data from consecutive patients who underwent primary hip arthroscopy between November 2014 and January 2017 were collected and analyzed. Baseline data and postoperative patient-reported outcome (PRO) scores were recorded at 2-years postoperatively. In order to quantify clinical significance of outcome achievement on the VAS Satisfaction we calculated MCID, PASS and SCB for this outcome measure. A multivariate logistic regression analysis was used to identify preoperative predictors of achieving SCB, PASS, and MCID satisfaction. Results: A total of 335 patients were included in the final analysis, with an average age and body mass index (BMI) of 32.8(SD+12.4) years and 25.2(SD+5.3) respectively. The values on the VAS satisfaction were identified to represent MCID, PASS and SCB respectively: 12.3, 80.9 and 89.7. The rates of achieving clinically significant improvement on the VAS Satisfaction was 97.1%, 68.1% and 56.9% for MCID, PASS and SCB respectively. A larger preoperative alpha angle was predictive for achieving SCB (OR:1.076; p =0.046), while lower BMI (OR:0.955; p =0.047) and larger preoperative alpha angle (OR:1.12; p-value=0.025) were predictors for achieving PASS. Conclusions: This study identifies scores on the VAS Satisfaction that can be used to define clinically significant outcome after arthroscopic treatment of FAIS. Specifically, an improvement of 12.3 points is a clinically important improvement in satisfaction, while an absolute score above 89.7 represents the upper threshold of Satisfaction performance. Almost all patients (97.1%) demonstrated a clinically important improvement in satisfaction. Additionally, there are both modifiable and non-modifiable factors that predict achieving a clinically significant level of post-operative satisfaction on the VAS Satisfaction.

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Etiological importance of training frequency, age and prevalance of Femoroacetabular İmpingement(FAİ) in pediatric male athletes

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967117s00067 ◽

2017 ◽

Vol 5 (2_suppl2) ◽

pp. 2325967117S0006

Author(s):

Gökhan Polat ◽

Ufuk Arzu ◽

Engin Dinç ◽

Bülent Bayraktar

Keyword(s):

Femoroacetabular Impingement ◽

Alpha Angle ◽

Statistical Relationship ◽

Male Athletes ◽

Positive Correlation ◽

Morphological Abnormalities ◽

Neck Shaft Angle ◽

Weekly Training ◽

Training Frequency ◽

Shaft Angle

Femoroacetabular impingement (FAİ) is a prearthrozic disease that causes hip pain in adolescent-adult patients. The aim of the study is, determining the prevalence of asymptomatic radiographic findings of FAİ, to examine the evaluation of prevalence difference according to age groups and the impact of the levels of physical activity at developmental period on the development of asymptomatic FAİ. Materials-Methods: In our study, we included 214 pediatric athletes from 8 football teams operating in Istanbul between 11-18 years of age in September 2015- January 2016. Ethics Committee approval was obtained for our study. AP pelvis and Frog-leg radiographs, curriculum vitae of the athletes, their injuries, and their realtime complaints have been questioned. The alpha angle, CE angle, Tonnis angle, collodiaphyseal angle is measured from the resulting AP and Frog leg radiographs and terms of morphological abnormalities (FAİ, dysplasia and coxa vara…) was noted. Also athletes dominant feet, weekly training period and the years they play soccer was noted. The obtained data were analyzed by one-way ANOVA and Student-T test. Results: The average age of the 214 pediatric male athletes that included was 15(10-18). Asymptomatic FAİ prevalence of all ages was %29.9, % 0 in the range of 10-12 years, %13.1 in the range of 13-15 years, %45.7 in the 15-18 age range. These findings showed that significantly increased prevalence of FAİ in line with age in pediatric athletes statistically (p <0.05). The mean right hip alpha angle of all athletes was 50.7, left alpha angle was 50.3, right-CE angle was 28.6, left CE angle was 29.5, right Tönnis Angle 6.6, left Tönnis angle 5.0, right neck-shaft angle 133.9, left neck-shaft angle 134.7 degrees found. There was 7 acetabular dysplasia, 56 athletes with CAM type FAS, 4 athletes Pincer type FAS, and 4 combined FAS was found. There was no significant statistical relationship in the prevalences of FAİ between the number of years he worked as an athlete or the side which they hit the ball. However a positive correlation was found between weekly training hours (p <0.05). There were no statistical relationship between morphological abnormalities and previous injuries. Discussion: Among the etiology oriented researches, investigation for developmental factors still continues. İn our study, it is found that the sports activities in the pediatric period that are accused can be a factor in FAİ development due to the positive correlation between pediatric athletes age ang training frequency.

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