Cam Deformity Research Articles

Prevalence of femoroacetabular impingement in elite baseball players.

ABSTRACTCAM-type femoroacetabular impingement continues to be an underrecognized cause of hip pain in elite athletes. Properties inherent to baseball such as throwing mechanics and hitting may enhance the risk of developing a cam deformity. Our goal is to gain an appreciation of the radiographic prevalence of cam deformities in elite baseball players. Prospective evaluation and radiographs of 80 elite baseball players were obtained during the 2016 preseason entrance examination. A sports medicine fellowship-trained orthopedic surgeon with experience treating hip disorders used standard radiographic measurements to assess for the radiographic presence of cam impingement. Radiographs with an alpha angle >55° on modified Dunn views were defined as cam positive. Of the 122 elite baseball players included in our analysis, 80 completed radiographic evaluation. Only 7.3% (9/122) of players reported hip pain and 1.6% (4/244) had a positive anterior impingement test. The prevalence of cam deformities in right and left hips were 54/80 (67.5%) and 40/80 (50.0%), respectively. The mean alpha angle for cam-positive right and left hips were 64.7 ± 6.9° and 64.9 ± 5.8°, respectively. Outfielders had the highest risk of right-sided cam morphology (Relative Risk (RR) = 1.6). Right hip cam deformities were significantly higher in right-handed pitchers compared with left-handed pitchers (P = 0.02); however, there was no significant difference in left hip cam deformities between left- and right-handed pitchers (P = 0.307). Our data suggest that elite baseball players have a significantly higher prevalence of radiographic cam impingement than the general population.

Comparative Reliability of 3-Tesla Magnetic Resonance Imaging to Arthroscopy Findings in Femoroacetabular Impingement

Purpose: We have found that 3-tesla magnetic resonance imaging (3TMRI) is as clinically effective as magnetic resonance (MR) arthrogram when it comes to investigating patients with femoroacetabular impingement (FAI). It is also a noninvasive procedure that can be done more efficiently, with equivalent radiological and surgical outcomes. We would recommend 3TMRI as the primary investigation for patients presenting with FAI-type symptoms. Methods: This was a retrospective review of a single surgeon series of 59 operative cases, over 3 years. The inclusion criteria were arthroscopically confirmed diagnosis of FAI and preoperative imaging with 3TMRI scans. The surgical reports were analyzed and compared to the radiological reports, that were produced independently by two consultant musculoskeletal radiologists. The key findings included were the presence of labral tear, femoral CAM deformity, and acetabular and femoral cartilage damage. Results: We found that 3T MRI is sensitive in detecting the presence of labral tears and CAM deformities. (96% and 83% respectively). It was however, less sensitive in detecting femoral and acetabular cartilage damage. (50% and 69% respectively). The specificity of excluding cartilage wear on both the femoral and acetabular side was also high, (83% and 86%) but low for labral tears and CAM deformities (9% and 69%). The positive predictive value of 3TMRI was high in labral tears, CAM deformities, and acetabular wear (82%, 74%, and 97%) but low in predicting femoral cartilage damage (25%). The negative predictive value was high in detecting CAM lesions and femoral wear (80% and 94%) but low for labral tears and acetabular wear (33% and 27%). Conclusion: 3T MRI is particularly good at detecting the presence of labral tears, and CAM deformities. It is less sensitive at detecting cartilage damage, but more accurate in diagnosing the location of cartilage wear when present. This is a level 3 study, being a retrospective case–control study. The clinical relevance of this study is to determine if the less invasive 3TMRI study can be used to substitute for MR arthrography in the diagnosis of FAI in patients.

Development of Cam Impingement following Operative Fixation of Acetabular Fractures

AbstractThe development of femoroacetabular impingement following acetabular fracture fixation is under-recognized. This study assessed radiographic changes of the hip joint after acetabular fracture fixation, and the clinical implications of associated radiographic changes. Institutional review of patients under age 40 who underwent acetabular fracture fixation from 2010 to 2016 with minimum 1-year radiographic follow-up was performed. Two independent evaluators compared immediate postoperative radiographs and those at final follow-up for basic radiographic parameters. Chi-squared test, Fisher's exact test, and two-tailed t-tests were used to compare those with and without cam lesion development. Two-hundred twenty-four hips were reviewed, with 55 hips (53 patients) meeting inclusion criteria (age = 29.2 years, 60% male, average follow-up = 2.1 years). Average α angle increased from 53.8 to 75.5 degrees postfixation (p < 0.001). Average immediate postoperative joint space was unchanged from that at follow-up (3.6 versus 3.6 mm, p = 0.90), and there was no association between joint space narrowing and cam lesion development. Forty-four hips had postoperative α angles of less than 65 degrees. At final follow-up, 26/44 hips (59.1%) had α angles of greater than 65 degrees. Lower body mass index was an independent risk factor for increase in α-angle (p < 0.05). Hip dislocation, acetabular fracture pattern, age, and joint space narrowing were not risk factors for the development of cam deformity. Two patients had undergone hip preservation procedures at the last follow-up. Our findings identify the development of primarily femoral-sided femoroacetabular impingement following acetabular fracture fixation and highlight the importance of prolonged postoperative follow-up for these patients. Providers should scrutinize radiographs in those with new-onset pain or poor satisfaction following acetabular fixation.

Sex-Based Differences in Femoroacetabular Impingement Syndrome and the Effect of Cam Deformity Location on the Extent of Labral Tearing: A 3-Dimensional Computed Tomography Study.

Sex-specific quantification of cam morphology in patients with femoroacetabular impingement syndrome may improve diagnostics, surgical planning, and outcomes. To (1) examine differences between men and women with symptomatic cam deformities based on deformity location, magnitude, and extent; (2) assess the association between cam deformity and labral pathology; and (3) evaluate the relationship between cam deformity and patient-reported outcome measures after hip arthroscopy. Cohort study; Level of evidence, 3. Computed tomography (CT) scans were acquired in 98 consecutive patients before hip arthroscopy for femoroacetabular impingement syndrome. Custom software was used to generate 3-dimensional bone models and align them to a standard coordinate system. The alpha angle was measured at the 12-, 1-, 2-, and 3-o'clock positions, with 12 and 3 o'clock corresponding to the superior and anterior aspects of the femur, respectively. These alpha angle measurements were used to define the cam midpoint and extent. The labral tear midpoint and extent were evaluated intraoperatively. Bivariate correlation analysis was used to evaluate the association between the cam and labral tear midpoints and between the extent of the cam morphology and labral tearing. The 3-dimensional models were analyzed in a cohort of 69 female and 29 male patients. Male patients were older (mean ± SD, 38.9 ± 12.6 vs 30.7 ± 12.2 years, P = .006) and had a greater body mass index (27.8 ± 4.4 vs 25.3 ± 5.6 kg/m2, P = .005). Male patients had greater alpha angle measures at 12, 1, and 3 o'clock (P < .05) and a greater maximum alpha angle (69.0° ± 18.8° vs 62.1° ± 21.0°, P = .031); the location of their maximum cam impingement was also significantly different (P < .05) when compared with female patients. Cam impingement (2:06 ± 1:09 vs 1:33 ± 1:16 clockfaces, P = .032) and labral tearing (3:02 ± 0:35 vs 2:34 ± 0:53 clockfaces, P = .003) in men extended over a greater region of the femoral clockface when compared with women. Significant correlations were demonstrated between the cam and labral tear midpoint locations (r = 0.190, P = .032) and the extent of the cam deformity and labral tearing (r = 0.203, P = .024). There were no sex-based differences in patient-reported outcome measures at baseline or 2-year follow-up. Male patients possessed greater cam deformity magnitude and extent when compared with female patients. Cam pathomorphology was associated with the location and extent of labral tearing.

Three-Dimensional Quantification of Cam Resection Using MRI Bone Models: A Comparison of 2 Techniques.

Background:The current clinical standard for the evaluation of cam deformity in femoroacetabular impingement syndrome is based on radiographic measurements, which limit the ability to quantify the complex 3-dimensional (3D) morphology of the proximal femur.Purpose:To compare magnetic resonance imaging (MRI)–based metrics for the quantification of cam resection as derived using a best-fit sphere alpha angle (BFS-AA) method and using 3D preoperative-postoperative surface model subtraction (PP-SMS).Study Design:Descriptive laboratory study.Methods:Seven cadaveric hemipelvises underwent 1.5-T MRI before and after arthroscopic femoral osteochondroplasty, and 3D bone models of the proximal femur were reconstructed from the MRI scans. The alpha angles were measured radially along clockfaces using a BFS-AA method from the literature and plotted as continuous curves for the pre- and postoperative models. The difference between the areas under the curve for the pre- and postoperative models was then introduced in the current study as the BFS-AA–based metric to quantify the cam resection. The cam resection was also quantified using a 3D PP-SMS method, previously described in the literature using the metrics of surface area (FSA), volume (FV), and height (maximum [FHmax] and mean [FHmean]). Bivariate correlation analyses were performed to compare the metrics quantifying the cam resection as derived from the BFS-AA and PP-SMS methods.Results:The mean ± standard deviation maximum pre- and postoperative alpha angle measurements were 59.73° ± 15.38° and 48.02° ± 13.14°, respectively. The mean for each metric quantifying the cam resection with the PP-SMS method was as follows: FSA, 540.9 ± 150.7 mm2; FV, 1019.2 ± 486.2 mm3; FHmax , 3.6 ± 1.0 mm; and FHmean, 1.8 ± 0.5 mm. Bivariate correlations between the BFS-AA–based and PP-SMS–based metrics were strong: FSA (r = 0.817, P = .012), FV (r = 0.888, P = .004), FHmax (r = 0.786, P = .018), and FHmean (r = 0.679, P = .047).Conclusion:Strong positive correlations were appreciated between the BFS-AA and PP-SMS methods quantifying the cam resection.Clinical Relevance:The utility of the BFS-AA technique is primarily during preoperative planning. The utility of the PP-SMS technique is in the postoperative setting when evaluating the adequacy of resection or in patients with persistent hip pain with suspected residual impingement. In combination, the techniques allow surgeons to develop a planned resection while providing a means to evaluate the depth of resection postoperatively.

A Novel Model of Hip Femoroacetabular Impingement in Immature Rabbits Reproduces the Distinctive Head-Neck Cam Deformity

Background: Femoroacetabular impingement (FAI) is a leading cause of hip pain in young adults and often leads to degenerative osteoarthritis (OA). A small animal model of hip deformities is crucial for unraveling the pathophysiology of hip OA secondary to FAI. Purposes: To (1) characterize a new minimally invasive surgical technique to create a proximal femoral head–neck deformity in a skeletally immature rabbit model and (2) document the effect of an injury to the medial proximal femoral epiphysis on head–neck morphology at 28 days after the injury. Study Design: Controlled laboratory study. Methods: Six-week-old New Zealand White rabbits (n = 10) were subjected to right hip surgery, with the left hip used as a control. An epiphyseal injury in the medial femoral head was created using a 1.6-mm drill. Hips were harvested bilaterally at 28 days after surgery. Alpha and epiphyseal shaft angles were measured on radiographs. Alpha angles at the 1- and 3-o’clock positions were measured on the oblique axial plane of micro–computed tomography images. Bone bar formation secondary to growth plate injuries was confirmed using alcian blue hematoxylin staining. Results: All hips in the study group showed a varus–type head-neck deformity, with lower epiphyseal shaft angles on anteroposterior radiographs versus those in the control group (133°± 8° vs 142°± 5°, respectively; P = .022) and higher epiphyseal shaft angles on lateral radiographs (27°± 12° vs 10°± 7°, respectively; P < .001). The mean alpha angles in the study group were higher at both the 1- (103°± 14° vs 46°± 7°, respectively; P < .002) and 3-o’clock (99°± 18° vs 35°± 11°, respectively; P < .002) positions than those in the control group. Alcian blue hematoxylin staining of all hips in the study group indicated that the injured physis developed a bony bar, leading to growth plate arrest on the medial femoral head. Conclusion: The proposed model led to growth arrest at the proximal femoral physis, resulting in a femoral head–neck deformity similar to human FAI. Clinical Relevance: Our novel small animal model of a femoral head–neck deformity is a potential platform for research into the basic mechanisms of FAI disease progression and the development of disease–modifying therapies.

Athletes Undergoing Concomitant Hip Arthroscopy and Periacetabular Osteotomy Demonstrate Greater Than 80% Return-to-Sport Rate at 2-Year Minimum Follow-Up

To report minimum 2-year follow-up patient-reported outcomes and return-to-sport (RTS) rates in athletes undergoing concomitant hip arthroscopy and periacetabular osteotomy (PAO) to treat acetabular dysplasia and intra-articular pathologies such as cam deformity and labral tears. We reviewed the data of consecutive athletes undergoing concomitant primary hip arthroscopy and PAO for acetabular dysplasia and cam deformity from November 2010 to December 2018. Patients were included in the study if they had the following preoperative and minimum 2-year postoperative scores: modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), and Hip Outcome Score-Sport-Specific Subscale (HOS-SSS). The percentage of patients who achieved the minimal clinically important difference was recorded, in addition to RTS status. A total of 29 athletes (29 hips) were included, with a mean follow-up time of 34.1 ± 7.9 months, mean age of 26.0 ± 8.7 years, and mean body mass index of 23.7 ± 3.4. These athletes showed significant improvements in the mHHS, NAHS, and HOS-SSS from baseline to latest follow-up (P < .001). The minimal clinically important difference was achieved at high rates for the mHHS (82.8%), NAHS (86.2%), and HOS-SSS (79.3%). Athletes who attempted to RTS successfully returned at a rate of 81.8%. Athletes undergoing concomitant hip arthroscopy and PAO showed significant improvements in patient-reported outcomes at minimum 2-year follow-up and had an RTS rate of 81.8%. Level IV, retrospective case series.

Intra-articular injury patterns as evidence of mechanical hip disorders

FAIS is awell-defined clinical entity with morphological alterations, whether constitutional or acquired, that can lead to damage of the labrum and acetabular cartilage following distinct injury patterns with subsequent osteoarthritis. The combination pathology of cam and pincer deformity is the most common variant. The characteristic changes of the chondrolabral complex that are caused by the dysplasia differ from these FAIS changes. Furthermore, femoral torsion also has an impact on the clinical appearance of Cam- or Pincer-FAIS.

Evaluation of Differences Between Non-Hispanic White and African American Patients With Sports Medicine-Related Hip Disabilities.

Background:Racial disparities within the field of orthopaedics are well-documented in the spinal surgery, knee arthroplasty, and hip arthroplasty literature. Not much is known about racial differences in patients with sports medicine–related hip disabilities.Purpose:To investigate whether differences exist between African American and non-Hispanic White (White) patients evaluated for hip disabilities.Study Design:Cross-sectional study; Level of evidence, 3.Methods:We performed a multicenter retrospective cohort study of 905 patients who were evaluated over a 1-year period for hip-related orthopaedic concerns. Patient demographic data, disability characteristics, and hip radiographic findings were obtained from electronic medical records. We also obtained data on whether patients were offered physical therapy, magnetic resonance imaging (MRI), and/or surgery. Comparisons by race and insurance status were evaluated using univariate and multivariate analyses.Results:African Americans comprised a significantly lower proportion of the patients evaluated for hip-related disabilities compared with Whites (6.5% vs 93.5%; P < .001). A significantly smaller proportion of African Americans with hip disabilities was recommended for surgery than White patients (35.6% vs 54.6%; P = .007). Cam deformities were more common in White vs African American patients (39.7% vs 23.7%; P = .021), as were labral tears (54.1% vs 35.6%; P = .009). Logistic regression demonstrated that neither race nor insurance status were significant determinants in surgery recommendations. Conversely, race was a determinant of whether an MRI was performed, as White patients were 2.74 times more likely to have this procedure. There were no differences with respect to obtaining an MRI between private and Medicaid insurance.Conclusion:Compared with White patients, there were differences in both the proportion of African Americans evaluated for hip-related disabilities and the proportion receiving a surgery recommendation. African Americans with sports medicine–related hip issues were also less likely to obtain an MRI. With regard to observed pathology, African American patients were less likely to have cam deformities and labral tears than White patients.

Femoroacetabular impingement in the unpinned contralateral hip in patients with primary unilateral slipped capital femoral epiphysis: preliminary radiographic outcomes.

The study evaluated femoroacetabular impingement (FAI) in the unpinned contralateral hip in patients with unilateral slipped capital femoral epiphysis (SCFE) and verified initial age, posterior sloping angle (PSA) and center-edge angle (CEA) as predictors of FAI in the contralateral hip. 152 patients with unilateral SCFE with a mean index age of 13.2 years (8.2-17.2 years) were enrolled retrospectively into the study. Mean follow-up was 8 years (3-14 years). PSA and CEA were measured on initial radiographs of the unaffected hip. Alpha-angle and CEA were measured on radiographs taken at the last follow-up to identify FAI. Four groups of patients were distinguished: (1) no FAI (10 patients, 17.54%); (2) CAM-type FAI (41 patients, 71.9%); (3) pincer-type FAI (3 patients, 5.26%) and (4) mixed-type FAI (13 patients, 22.8%). The mean PSA was 12.1°, 12°, 16.8°, 11.9° for groups 1, 2, 3 and 4, respectively, with no significant difference ( P = 0.65). The mean initial CEA for groups 1, 2, 3 and 4 was 34.4°, 35.5°, 42° and 42° respectively, with significant differences between groups 1 versus 4 ( P = 0.034) and 2 versus 4 ( P = 0.009). Conclusions are as follows: 1. Radiographic features of FAI were present in 85.1% of unpinned contralateral hips in patients with unilateral SCFE. 2. 71.9% of unpinned contralateral hips developed CAM deformity. 3. CEA can be used in predicting pincer-type FAI in the contralateral hip in unilateral SCFE. 4. PSA and age revealed negligible value in predicting FAI.

Correlation between the range of rotation of the hip and the radiographic signs of cam and pincer morphology in femoroacetabular impingement syndrome.

ObjectiveTo determine whether hip rotation correlates with the radiographic signs of cam or pincer deformity after hip arthroscopy in patients with femoroacetabular impingement syndrome.Materials and MethodsThis was a single-center retrospective study of data collected between 2014 and 2017. The study sample included 65 patients between 18 and 55 years of age who underwent hip arthroscopy for the treatment of unilateral femoroacetabular impingement. The following data were collected for the periods prior to and six months after surgery range of medial and lateral rotation of the hip; measures on anteroposterior X-rays of the pelvis obtained in the standing position and on ateral X-rays in the Ducroquet profile view; and score on the 33-item International Hip Outcome Tool.ResultsMean preoperative and postoperative values were as follows: 19.26 ± 10.39° and 30.95 ± 3.52°, respectively, for medial rotation of the hip (p < 0.001); 73.85 ± 6.62° and 68.12 ± 5.04°, respectively, for the anteroposterior alpha angle (p < 0.001); 56.97 ± 6.09° and 50.61 ± 5.39°, respectively, for the lateral alpha angle (p < 0.001); and 0.17 ± 0.11 and 0.07 ± 0.08, respectively, for the acetabular retroversion index (p < 0.001). The crossover sign was identified in 75.4% of the patients before surgery and in 44.6% after (p < 0.001). Although there was an increase in the range of hip rotation and an improvement in radiographic parameters after arthroscopy, we detected no direct correlation between the two.ConclusionHip arthroscopy can improve medial rotation of the hip, as well as reducing cam and pincer deformities, in patients with femoroacetabular impingement syndrome. However, those findings do not appear to be directly correlated.

High prevalence of hip lesions secondary to arthroscopic over- or undercorrection of femoroacetabular impingement in patients with postoperative pain

ObjectivesTo compare the prevalence of pre- and postoperative osseous deformities and intra-articular lesions in patients with persistent pain following arthroscopic femoroacetabular impingement (FAI) correction and to identify imaging findings associated with progressive cartilage damage.MethodsRetrospective study evaluating patients with hip pain following arthroscopic FAI correction between 2010 and 2018. Pre- and postoperative imaging studies were analyzed independently by two blinded readers for osseous deformities (cam-deformity, hip dysplasia, acetabular overcoverage, femoral torsion) and intra-articular lesions (chondro-labral damage, capsular lesions). Prevalence of osseous deformities and intra-articular lesions was compared with paired t-tests/McNemar tests for continuous/dichotomous data. Association between imaging findings and progressive cartilage damage was assessed with logistic regression.ResultsForty-six patients (mean age 29 ± 10 years; 30 female) were included. Postoperatively, 74% (34/46) of patients had any osseous deformity including 48% (22/46) acetabular and femoral deformities. Ninety-six percent (44/46) had an intra-articular lesion ranging from 20% (9/46) for femoral to 65% (30/46) for acetabular cartilage lesions. Prevalence of hip dysplasia increased (2 to 20%, p = 0.01) from pre- to postoperatively while prevalence of cam-deformity decreased (83 to 28%, p < 0.001).Progressive cartilage damage was detected in 37% (17/46) of patients and was associated with extensive preoperative cartilage damage > 2 h, i.e., > 60° (OR 7.72; p = 0.02) and an incremental increase in postoperative alpha angles (OR 1.18; p = 0.04).ConclusionPrevalence of osseous deformities secondary to over- or undercorrrection was high. Extensive preoperative cartilage damage and higher postoperative alpha angles increase the risk for progressive degeneration.Key Points• The majority of patients presented with osseous deformities of the acetabulum or femur (74%) and with intra-articular lesions (96%) on postoperative imaging.• Prevalence of hip dysplasia increased (2 to 20%, p = 0.01) from pre- to postoperatively while prevalence of a cam deformity decreased (83 to 28%, p < 0.001).• Progressive cartilage damage was present in 37% of patients and was associated with extensive preoperative cartilage damage > 2 h (OR 7.72; p = 0.02) and with an incremental increase in postoperative alpha angles (OR 1.18; p = 0.04).

The natural history of alpha angle in the last seventeen centuries

Hip osteoarthritis is one of the most important and debilitating diseases affecting thousands of people all over the world. On the other hand, femoroacetabular impingement (FAI) is one of the known important causes of hip osteoarthritis. Cam deformity frequently presents in FAI showing an increased alpha angle. Increased alpha angle has been observed among young patients involved in demanding physical activities such as in sports (40-60%), whereas among the non-athletic population, increased alpha angle was observed in 15-20%. Although femoroacetabular pathology has been described over the recent years, it is not possible to determine when the angle increase actually begins prior to diagnosis. The aim of our study is to evaluate the femoral alpha angle in different human femurs in different civilization eras in West Mediterranean area. Available ancient femurs were selected from the Collection Center belonging to the archeological archives (ancient necropolis) from the fourth, fourteenth and eighteenth centuries. A comparison of the alpha angle was made of the measurements from the different groups accompanied by a sample of present-day femurs from the radiology database of CT scans. Data from 243 femoral bones were collected, 50 of which from the fourth century, 26 from the fourteenth century, 68 from the eighteenth century, and 99 femurs from the 20/twenty-first century. Alpha angles in all historical samples showed pathological values (> 55º) up to a maximum of 11.5% of the cases. Meanwhile, the actual series showed pathological alpha angle in 60.1% of the cases with statistical significant differences. The studied femurs of the western Mediterranean region from the fourth, fourteenth and eighteenth centuries showed pathological alpha angles in a smaller proportion than the actual sample. Level III, retrospective studies.

Is a Femoro-Acetabular Impingement Type Cam Predictable after Slipped Capital Femoral Epiphysis?

(1) Background: Previous studies have proven a high incidence of a femoro-acetabular impingement (FAI) type cam in patients sustaining a slipped capital femoral epiphysis (SCFE). Thus, the current study analyzed, if a cam deformity is predictable after SCFE treatment; (2) Methods: 113 cases of SCFE were treated between 1 January 2005 and 31 December 2017. The radiological assessment included the slip angle after surgery (referenced to the femoral neck (epiphyseal tilt) and shaft axis as Southwick angle) and the last available lateral center edge angle (LCEA), the acetabular- and alpha angle. A correlation was performed between these parameters and the last alpha angle to predict a FAI type cam; (3) Results: After a mean follow-up of 4.3 years (±1.9; 2.0–11.2), 48.5% of the patients showed a FAI type cam and 43.2% a dysplasia on the affected side. The correlation between the epiphyseal tilt and alpha angle was statically significant (p = 0.017) with a medium effect size of 0.28; (4) Conclusions: The postoperative posterior epiphyseal tilt was predictive factor to determine the alpha angle. However, the cut-off value of the slip angle was 16.8° for a later occurrence of a FAI type cam indicating a small range of acceptable deviations from the anatomical position for SCFE reconstruction.

1450 Relationship between Spinopelvic Parameters and Symptomatic Femoroacetabular Impingment: A Scoping Review

Abstract Aim Reports have shown that spinopelvic mobility influences the outcome following total hip arthroplasty. The aim of this scoping review was to investigate the relationship between spinopelvic parameters (SPP) and symptomatic femoroacetabluar impingement (FAI). Method A systematic computer search of EMBASE, PubMed and Cochrane for literature related to SPPs and FAI was undertaken as per PRISMA guidelines. Clinical outcome studies and prospective/retrospective studies that investigated the role of SPPs in symptomatic FAI were included. Review articles, case reports and book chapters were excluded. Information extracted pertained to symptomatic cam deformities, pelvic tilt, deviations in acetabular version, decreases in pain-free hip range of motion (ROM) on dynamic hip movements and radiological signs of FAI. Results The literature search identified 46 papers out of 1168 investigating the link between SPPs and pathological processes characteristic of FAI. Anteior pelvic tilt was associated with radiographic over-coverage parameters of FAI. Three studies associated FAI pathology with a greater pelvic incidence (PI), while four associated it with a smaller PI. In dynamic movements, decreased posterior pelvic tilt and reduced saggital pelvic ROM was found in symptomatic FAI patients during hip flexion. Conclusions Our study shows that spinopelvic parameters can influence radiological and clinical manifestations of FAI, with pelvic incidence, acetabular version and muscular imbalances being aetiologically implicated. Individual spinopelvic mobility may predispose to the development of FAI, which may be amenable to non-surgical management. If FAI pathoanatomy already exists however, sagittal pelvic parameters can influence whether FAI symptoms develop, and the extent to which they do so.

Hip Dislocation and Subluxation in Athletes: A Systematic Review

Background: Hip dislocation is a rare occurrence during sports but carries serious implications for athletes. Purpose: To systematically review treatment strategies and outcomes for hip dislocation in athletes, with the ultimate goal of providing sports medicine physicians with the information necessary to appropriately treat and counsel patients sustaining this injury. Study Design: Systematic review; Level of evidence, 4. Methods: PubMed, MEDLINE, and Embase were searched for studies relating to hip instability and athletics from January 1, 1989 to October 1, 2019. s and articles were evaluated on the basis of predefined inclusion and exclusion criteria. Inclusion criteria were the following: (1) data from ≥1 patients, (2) native hip dislocation or subluxation occurring during sports, (3) patients aged at least 10 years, and (4) written in English. Exclusion criteria were (1) patients younger than 10 years; (2) nonnative or postoperative hip dislocation or subluxation; (3) a native hip injury without dislocation or subluxation; (4) patients with dislocation or subluxation secondary to neuromuscular, developmental, or syndromic causes; (5) dislocation or subluxation not occurring during sports; (6) patients with physeal fractures; or (7) review articles or meta-analyses. Data were recorded on patient demographics, injury mechanism, treatment strategies, and clinical and radiographic outcomes. Where possible, pooled analysis was performed. Studies were grouped based on reported outcomes. Meta-analysis was then performed on these pooled subsets. Results: A total of 602 articles were initially identified, and after screening by 2 reviewers, 27 articles reporting on 145 patients were included in the final review. There were 2 studies that identified morphological differences between patients with posterior dislocation and controls, including decreased acetabular anteversion (P = .015 and .068, respectively), increased prevalence of a cam deformity (P < .0035), higher alpha angles (P≤ .0213), and decreased posterior acetabular coverage (P < .001). No differences were identified for the lateral center edge angle or Tonnis angle. Protected postreduction weightbearing was most commonly prescribed for 2 to 6 weeks, with 65% of reporting authors recommending touchdown, toe-touch, or crutch-assisted weightbearing. Recurrence was reported in 3% of cases. Overall, 4 studies reported on findings at hip arthroscopic surgery, including a 100% incidence of labral tears (n = 27; 4 studies), 92% incidence of chondral injuries, 20% incidence of capsular tears, and 84% incidence of ligamentum teres tears (n = 25; 2 studies). At final follow-up, 86% of patients reported no pain (n = 14; 12 studies), 87% reported a successful return to play (n = 39; 10 studies), and 11% had radiographic evidence of osteonecrosis (n = 38; 10 studies). Conclusion: Various treatment strategies have been described in the literature, and multiple methods have yielded promising clinical and radiographic outcomes in patients with native hip dislocation sustained during sporting activity. Data support nonoperative treatment with protected weightbearing for hips with concentric reduction and without significant fractures and an operative intervention to obtain concentric reduction if unachievable by closed means alone. Imaging for osteonecrosis is recommended, with evidence suggesting 4- to 6-week magnetic resonance imaging and follow-up at 3 months for those with suspicious findings in the femoral head.

Capsular Management with Traction-Assisted T-Capsulotomy Technique During Hip Arthroscopy

Capsular management, from the initial capsulotomy to capsule closure is essential to success in hip arthroscopy to achieve optimal outcomes. Although an interportal capsulotomy is typically sufficient for resection of proximal cam lesions and for performing central compartment procedures, T-capsulotomy is usually performed when large cam deformity needs to be addressed because it provides a broader field of view. The purpose of this Technical Note is to summarize each step of capsule management and to define a traction-assisted T-capsulotomy technique that allows for accurate placement of the T-capsulotomy while also avoiding damage to the articular cartilage.

Outcomes following surgical management of femoroacetabular impingement: a systematic review and meta-analysis of different surgical techniques

Outcomes following different types of surgical intervention for femoroacetabular impingement (FAI) are well reported individually but comparative data are deficient. The purpose of this study was to conduct a systematic review (SR) and meta-analysis to analyze the outcomes following surgical management of FAI by hip arthroscopy (HA), anterior mini open approach (AMO), and surgical hip dislocation (SHD). This SR was registered with PROSPERO. An electronic database search of PubMed, Medline, and EMBASE for English and German language articles over the last 20 years was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We specifically analyzed and compared changes in patient-reported outcome measures (PROMs), α-angle, rate of complications, rate of revision, and conversion to total hip arthroplasty (THA). A total of 48 articles were included for final analysis with a total of 4,384 hips in 4,094 patients. All subgroups showed a significant correction in mean α angle postoperatively with a mean change of 28.8° (95% confidence interval (CI) 21 to 36.5; p < 0.01) after AMO, 21.1° (95% CI 15.1 to 27; p < 0.01) after SHD, and 20.5° (95% CI 16.1 to 24.8; p < 0.01) after HA. The AMO group showed a significantly higher increase in PROMs (3.7; 95% CI 3.2 to 4.2; p < 0.01) versus arthroscopy (2.5; 95% CI 2.3 to 2.8; p < 0.01) and SHD (2.4; 95% CI 1.5 to 3.3; p < 0.01). However, the rate of complications following AMO was significantly higher than HA and SHD. All three surgical approaches offered significant improvements in PROMs and radiological correction of cam deformities. All three groups showed similar rates of revision procedures but SHD had the highest rate of conversion to a THA. Revision rates were similar for all three revision procedures.

Arthroscopic Treatment of Femoroacetabular Impingement Syndrome with Bone Cyst at Femoral Head-Neck Junction: Case Report and Literature Review

In recent years, with the development of imaging and arthroscopy techniques, and a deep understanding of the pathogenic mechanism of femoroacetabular impingement syndrome (FAI), more and more scholars have gained a greater knowledge of the diagnosis and treatment of the disease. FAI not only has abnormal bone structure, such as cam deformity at the femoral head-neck junction, acetabular osteophyte formation, and bone cyst at the femoral or acetabulum, but also leads to the soft tissue injury of the hip joint, like acetabulum cartilage and labrum lesion, which might accelerate the progression of hip osteoarthritis. The incidence of bone cyst or synovial hernia at the femoral head-neck junction is not rare, which was seen as a sign of impingement. However, there is a paucity of literature about the treatment of bone cyst and the clear standard protocols of treatment, especially large or polycystic cysts. In this study, we reported a case of Cam FAI complicated with a giant bone cyst at the femoral head-neck junction and its characteristics and arthroscopic treatment. We also reviewed relevant documents and summarized the protocols of management of FAI complicated with femoral head-neck bone cyst for clinical reference.

Movement Patterns and Their Associations With Pain, Function, and Hip Morphology in Individuals With Femoroacetabular Impingement Syndrome: A Scoping Review.

The purpose of the study was to synthesize studies of movement patterns and their association with hip pain, function/activity, and morphology in individuals with femoroacetabular impingement syndrome (FAIS). PubMed, SPORTDiscus, CINAHL, Embase, and Scopus databases were searched using predefined terms. Two authors independently reviewed abstracts and full texts. Studies were included if they enrolled individuals with FAIS, reported kinematic or kinetic data during movement tasks, and tested the data's associations with hip pain, function/activity, or morphology. Exclusion criteria were studies that did not evaluate associations between movement patters and pain, function/activity, or hip morphology. Additionally, studies with hip conditions other than FAIS, case reports, conference proceedings, review articles, and non-English studies were excluded. Descriptive consolidation and qualitative synthesis were performed for the included studies. Of the 1155 potential studies, 5 studies metall eligibility criteria. Movement patterns were evaluated during walking (n = 4) and squatting (n = 1). Studies reported multiple associations between variables of interest. Statistically significant associations were identified between movement patterns and hip pain (n = 2), function/activity (n = 2), or morphology (n = 3). Significant associations included increased hip flexion moment impulse during walking was associated with worse pain, increased hip flexion moment during walking was associated with worse hip function, decreased hip external rotation during gait and hip internal rotation during squat were associated with larger cam deformity, and increased hip flexion moment impulse during walking was also associated with more severe acetabular cartilage abnormalities. Very little current evidence has evaluated the associations between altered movement patterns and hip pain, function/activity, or morphology in individuals with FAIS, and only low-intensity tasks have been tested. These studies found some preliminary associations between altered hip biomechanics and higher hip pain, worse hip function, and specific measures of hip morphology in individuals with FAIS. This review is a first step in gaining a better understanding of movement patterns and their associations with hip pain, function/activity, and morphology, which could ultimately assist with the development of movement retraining interventions and potentially improve rehabilitation outcomes for those with FAIS.