Etiology and Pathomechanics of Femoroacetabular Impingement

A novel radiographic finding for estimation of the cortical-cancellous boundary: A magnetic resonance imaging case series of patients with femoroacetabular impingement

Purpose

To determine if comparing alpha angle measurements of the outer cortical margin (preoperative alpha angle) and the inner cortical margin (theoretical postoperative alpha angle) on magnetic resonance imaging (MRI) can estimate the amount of sclerotic bone that needs to be resected to restore the alpha angle to normative values (<55⁰) in patients with symptomatic femoroacetabular impingement (FAI).

Methods

A retrospective review was conducted on patients with FAI undergoing primary hip arthroscopy and CAM osteoplasty from June 2013 to February 2017. Inclusion criteria were radiologist-measured alpha angles >70° on 3T oblique axial MRI, unilateral primary hip arthroscopy, and age ≥18. Exclusions included previous hip surgery, hip trauma, avascular necrosis, advanced osteoarthritis, dysplasia, poor quality images, or missing MRI images. Alpha angles were measured preoperatively using the outer cortical margin and postoperatively using the inner cortical margin of femur. Surgeries were performed by the senior surgeon. Paired t-tests compared preoperative and postoperative alpha angles, and intraclass correlation coefficients (ICC) were used to assess inter-rater and intra-rater reliability.

Results

One hundred patients (100 hips) were included with an average age of 40.8 years (range, 18.7-64.9), with 75 % being male (n = 75). The average BMI was 24.7 ± 3.9 (range, 17.1-38.8). The average maximum alpha angle at the outer cortical margin was 77.0 ± 4.2° (range, 70.0-90.8), with an ICC for inter-rater reliability of 0.861, indicating excellent agreement. The average inner cortical alpha angle was 46.4 ± 3.4° (range, 36.5-55.4), significantly less than 55° (p<0.001). The mean difference between the outer and inner cortical alpha angles was -30.6 ± 5.1° (p< 0.001).

Conclusions

The difference between outer and inner cortical alpha angles on MRI can accurately estimate the amount of sclerotic bone resection needed to restore the alpha angle to normative values in patients with FAI. This information may be directly applied clinically marker to assess adequacy of CAM resection.

Current understanding of articular cartilage lesions in femoroacetabular impingement syndrome

The concept of femoroacetabular impingement syndrome (FAIS) has received much attention over the past 20 years. Currently, it is believed that FAIS can lead to intra-articular pathologies such as labral tears and articular cartilage lesions, resulting in clinical symptoms and subsequent poor clinical outcomes. FAIS-related articular cartilage lesions are common but unique, and their natural course always leads to early osteoarthritis of the hip. However, despite these cartilage lesions having gradually gained considerable attention, limited consensus has been reached on key aspects, such as diagnosis, mechanisms, classification, and management strategies, which limits clinical and research advances. Hence, an intensive comprehensive overview based on the existing evidence is necessary. The purpose of this review was to introduce the general consensus, controversial issues, and recent advances in FAIS-related articular cartilage lesions.

Review of femoroacetabular impingement syndrome

Femoroacetabular impingement syndrome (FAIS) is a common condition of the hip that can cause significant damage to the joint, leading to degeneration and osteoarthritis. FAIS constitutes an abnormal and dynamic contact between the femoral head-neck junction and the acetabular rim, resulting from altered bone morphology at one or both sites. Repetitive trauma at the site of impingement generates progressive damage to the acetabular labrum, chondrolabral junction, and articular cartilage. Proper diagnosis based on patient symptoms, specific clinical signs, and imaging findings will guide treatment and ultimately allow preservation of the native hip joint. Common symptoms in patients with FAIS include pain, clicking, catching, buckling, stiffness, giving way, and a limited range of motion of the hip. Specific clinical maneuvers can aid diagnosis, such as flexion adduction internal rotation and flexion abduction external rotation tests. Imaging diagnosis includes orthogonal hip and pelvis X-ray views, as well as magnetic resonance imaging/magnetic resonance arthrogram imaging. Initial treatment of FAIS can be conservative and include physical therapy, intra-articular injections, and activity modification. Currently, the preferred surgical management consists of hip arthroscopy, which aims to correct bony abnormalities, repair or reconstruct labral lesions and address other intra-articular and extra-articular derangements as needed.

Diagnostic Capability of Intra-Articular Injections for Femoroacetabular Impingement Syndrome: A Systematic Review

OBJECTIVE

To review and critically appraise available literature concerning the diagnostic capability of intra-articular injections for femoroacetabular impingement (FAI) syndrome.

DESIGN

Systematic review.

SETTING

N/A.

PARTICIPANTS

N/A.

INTERVENTIONS

N/A.

MAIN OUTCOME MEASURES

Studies assessing pain relief following intra-articular injections for the diagnosis of FAI syndrome, compared with arthroscopy as diagnostic reference standard, were considered eligible. Searches were performed across 8 databases, and the risk of bias was evaluated through the Quality Assessment of Diagnostic Accuracy Studies tool.

RESULTS

From 489 articles identified, 4 were included for analysis. Intra-articular injections were composed of anesthetic agents (such as lidocaine, bupivacaine, and ropivacaine), combined or not with corticosteroids (triamcinolone and betamethasone). All studies were judged as "at risk of bias", and a substantial heterogeneity was found considering assessment methods and pain relief thresholds for a positive response to intra-articular injections. Overall, 2 studies reported that intra-articular injections presented a high accuracy in determining the presence of FAI syndrome. However, the remaining 2 studies indicated that intra-articular injections might present restricted diagnostic capability to discriminate FAI syndrome from healthy individuals or those with other hip pathologies.

CONCLUSIONS

Based on limited evidence, the diagnostic capability of intra-articular injections for FAI syndrome cannot be supported. It remains unclear which pain relief thresholds are related to a higher diagnostic capability. The combination of anesthetics with corticosteroids should also be further explored, including multiple pain assessments for evaluation of prolonged effects.

Two-Year Outcomes of Primary Arthroscopic Surgery in Patients with Femoroacetabular Impingement: A Comparative Study of Labral Repair and Labral Reconstruction

BACKGROUND

Labral repair has become the preferred method for the arthroscopic treatment of acetabular labral tears that are associated with femoroacetabular impingement (FAI) resulting in pain and dysfunction. Labral reconstruction is performed mainly in revision hip arthroscopy but can be utilized in the primary setting for absent or calcified labra. The purpose of this study was to compare the minimum 2-year patient-reported outcomes (PROs) and risk of revision or conversion to arthroplasty between primary labral reconstruction and primary labral repair.

METHODS

Patients with FAI who underwent primary hip arthroscopy with labral repair or reconstruction performed by the senior author between 2006 and 2018 were identified from a prospectively enrolled patient outcome registry. Exclusion criteria included confounding injuries, dysplasia, prior ipsilateral hip surgery, or a joint space of <2 mm. Patients who were 18 to 80 years old were eligible for inclusion. Multiple regression with inverse propensity score weighting was conducted to estimate the average treatment effect in the treated (ATT) for labral reconstruction versus labral repair with respect to postoperative PROs and the likelihood of subsequent surgery (revision hip arthroscopy or conversion to arthroplasty). PRO end points included the Hip Outcome Score Activities of Daily Living subscale (HOS-ADL), modified Harris hip score, Western Ontario and McMaster Universities Osteoarthritis Index total score (WOMAC), 12-Item Short Form Health Survey Physical Component Summary score (SF-12 PCS), and patient satisfaction.

RESULTS

A total of 150 hips undergoing primary labral reconstruction and 998 hips undergoing primary labral repair were included. The median follow-up time was 5.3 years in the reconstruction group and 5.8 years in the repair group. Compared with labral repair, labral reconstruction was associated with a higher risk of conversion to total hip arthroplasty (THA) (20% versus 7%; adjusted odds ratio, 3.2; 95% confidence interval [CI], 1.2 to 8.8; p = 0.024). Inverse propensity score-weighted multiple regression estimated a significant negative effect of labral reconstruction, relative to labral repair, on the postoperative values for the HOS-ADL (ATT, -3.3; 95% CI, -5.8 to -0.7; p = 0.012) and WOMAC (ATT, 2.6; 95% CI, 0.1 to 5.2; p = 0.044).

CONCLUSIONS

Compared with primary labral reconstruction, primary labral repair resulted in better postoperative HOS-ADL and WOMAC values and decreased conversion to THA. These findings were demonstrated in both the unadjusted group comparisons and multivariable modeling. These data support the use of labral repair in the primary setting of labral tears and the reservation of labral reconstruction for more advanced labral pathology or for revision cases.

LEVEL OF EVIDENCE

Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Arthroscopic Pincer Resection Utilizing an Outside-In Approach for Intra-articular Access

In the standard approach to hip arthroscopy, access to the joint is achieved using fluoroscopic guidance to enter the central compartment of the hip using the Seldinger technique, penetrating the capsule with a needle and subsequently cannulating and obtaining direct visualization of the joint. In such a way, arthroscopists then proceed with accessory portal creation and capsulotomy, as desired, under direct intra-articular visualization. In cases with severe pincer morphology or coxa profunda, it may not be possible to safely access the central compartment under fluoroscopic guidance due to significant lateral overcoverage of the femoral head. We present an outside-in arthroscopic approach for accessing the hip joint in such patients, allowing for safe visualization, osseous pincer resection, and improved central compartment access while minimizing the risk to cartilage and labral tissue.

How to start with hip arthroscopy in a safe and effective manner, using an evidence-based approach

Hip arthroscopy is a rapidly evolving field in orthopedics, offering diagnostic and therapeutic benefits for a range of hip pathologies. This review outlines a comprehensive guide to initiating hip arthroscopy safely and effectively using evidence-based practices. Optimal surgical outcomes depend on correct indications for surgery, in particular in the presence of borderline dysplasia and degenerative joint diseases. Proper patient counseling and setting realistic expectations are crucial for satisfactory outcomes and recovery. Physical examination, radiographs, MRI, and CT scans are essential for accurate diagnosis. In case of diagnostic uncertainty, the use of intra-articular injections can help confirm the diagnosis before surgery. Techniques for hip arthroscopy include central compartment first, peripheral compartment first, and outside-in approaches. Each technique has advantages, and the optimal approach depends on the specific case. Finally, Proper operating room setup, meticulous patient positioning, and precise portal placement are critical for a successful procedure. A thorough understanding of the safe zone anatomy for portal placement is essential to minimize the risk of neurovascular complications. In conclusion, this manuscript provides a detailed, evidence-based framework for starting hip arthroscopy, emphasizing the importance of technical proficiency, patient selection, and a multidisciplinary approach to ensure patient safety and procedure efficacy.

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

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.

Initial Assessment and Management of Select Musculoskeletal Injuries: A Team Physician Consensus Statement

ABSTRACT

Musculoskeletal injuries occur frequently in sport during practice, training, and competition. Injury assessment and management are common responsibilities for the team physician. Initial Assessment and Management of Musculoskeletal Injury-A Team Physician Consensus Statement is title 23 in a series of annual consensus documents written for the practicing team physician. This statement was developed by the Team Physician Consensus Conference, an annual project-based alliance of six major professional associations. The goal of this document is to help the team physician improve the care and treatment of the athlete by understanding the initial assessment and management of selected musculoskeletal injuries.

Initial Assessment and Management of Select Musculoskeletal Injuries: A Team Physician Consensus Statement

ABSTRACT

Musculoskeletal injuries occur frequently in sport during practice, training, and competition. Injury assessment and management are common responsibilities for the team physician. Initial Assessment and Management of Musculoskeletal Injury-A Team Physician Consensus Statement is title 23 in a series of annual consensus documents written for the practicing team physician. This statement was developed by the Team Physician Consensus Conference, an annual project-based alliance of six major professional associations. The goal of this document is to help the team physician improve the care and treatment of the athlete by understanding the initial assessment and management of selected musculoskeletal injuries.

The influence of the sacral slope on pelvic kinematics and clinical manifestations in femoroacetabular impingement

INTRODUCTION

The radiological study of the sagittal alignment of the spine in static and dynamic positions has allowed a better understanding of the clinical results of total hip prostheses. According to the Roussouly classification, the sacral slope in a standing position characterizes the patient with a stiff spine (less than 35̊) or a flexible spine (greater than 35̊). The objectives of this study were to compare, in a population of patients operated on for femoroacetabular impingement (FAI), firstly, the kinematics of the lumbar-pelvic-femoral complex and secondly, the clinical presentation depending on whether the spine is stiff or flexible.

HYPOTHESIS

Patients with stiff spines (SS<35̊) were "hip users" and had less ability to compensate for their hip pathology.

MATERIAL AND METHOD

This prospective and comparative multicenter study was conducted with patients operated on arthroscopically for FAI between 2020 and 2021. All patients included received preoperative EOS imaging of the lower limbs and spine, in standing and seated positions. The following parameters were measured: pelvic tilt (PT), pelvic incidence (PI), lumbar lordosis (LL), and sacral slope (SS), as well as dynamic parameters (intrinsic mobility of the hip: delta standing/sitting femoral sacral angle, and of the pelvis: delta standing/sitting sacral slope). The functional result was evaluated at 1 year.

RESULTS

In the stiff spine group, 62 patients were included versus 138 in the flexible spine group. The mean follow-up was 15.1±3.3 months (9.2-24.3). Nineteen patients were lost to follow-up and there were 2 revisions for iterative arthroscopy. Intrinsic pelvic mobility and intrinsic hip mobility were 16̊±13.5 (-12; 44) and 44.5̊±28.5 (-9; 99) respectively in the stiff spine group. In the flexible spine group, these same measurements were 22̊±11.5 (-30; 45) and 29.7̊±22.7 (-33; 82) respectively. In the stiff spine group, the symptoms occurred at a significantly younger age: 28.3 years±9.5 (18-51) versus 31 years±8 (18-54) (p=0.017).

DISCUSSION

The sacral slope is a determining factor in the kinematics of impingement and the appearance of symptoms. The sacral slope helps define the concept of a "hip user" in symptomatic FAI.

LEVEL OF EVIDENCE

IV.

Unravelling the hip-spine dilemma from the CHECK-cohort: is sagittal pelvic morphology linked to radiographic signs of femoroacetabular impingement?

INTRODUCTION

To date the aetiology of femoroacetabular impingement (FAI) is still not completely understood. There are mechanical theories that suggest symptomatic FAI is linked to sagittal pelvic morphology and spinopelvic-femoral dynamics. The aim of this study is to evaluate the relation of sagittal pelvic morphology and orientation to radiographic signs of FAI. Additionally, we test whether the relation between FAI and spinopelvic parameters differs in osteoarthritic hips.

METHODS

From a prospective, observational cohort study, 1002 patients between 45 and 65 years old with a first episode of knee or hip pain were followed for 8 years. All patients who had lateral lumbar radiographs and clinical and radiographic follow-up of the hips were included in the present study. Range of internal rotation of the hip as well as radiographic signs of FAI (alpha and Wiberg angle) and presence of hip osteoarthritis (Kellgren and Lawrence) were systematically measured at baseline. Pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS)) were measured at 8-year follow-up. Associations between PI, PT, SS and FAI parameters were tested using generalised estimating equations.

RESULTS

421 subjects, 842 hips, were included. No significant relations between PI, PT or SS and alpha or Wiberg angle were found. Comparison of hips with and without radiological sign(s) of FAI showed no differences in PI, PT or SS. There was no relation between range of internal rotation of the hip and spinopelvic parameters.

CONCLUSION

Sagittal pelvic morphology and orientation are not related to the presence of radiological signs of FAI in this study population.

Inflammatory and Immunologic Contributions in Femoroacetabular Impingement Syndrome

Femoroacetabular impingement (FAI) is one of the most common causes of labral and early cartilage damage in the nondysplastic hip. FAI is increasingly recognized as a cause for hip and groin pain in the young, active patient, and the surgical treatment of FAI with hip arthroscopy has risen exponentially. Although our understanding of FAI and the progression to degenerative osteoarthritis of the hip has historically been considered a mechanical "wear-and-tear" disease of an imperfectly shaped, aspherical, femoral head within a deep or overcovering acetabulum leading to cartilage injury, our understanding of the intrinsic pathophysiologic mechanisms underlying the development of FAI and joint degeneration of the hip remains poor. For example, many patients with FAI morphology may never develop hip pain or osteoarthritis; there remains more to discover regarding the pathophysiology of arthritis in the setting of FAI. Recent work has begun to identify a strong inflammatory and immunologic component to the FAI disease process that affects the hip synovium, labrum, and cartilage and may be detectable from peripheral clinical samples (blood and urine). This review highlights our current understanding of the inflammatory and immunologic contributions to FAI and potential therapeutic strategies to supplement and augment the surgical management of FAI.

Open and arthroscopic management of femoroacetabular impingement: a review of current concepts

Femoroacetabular impingement (FAI) is a common femoral and/or acetabular abnormality that can cause progressive damage to the hip and osteoarthritis. FAI can be the result of femoral head/neck overgrowth, acetabular overgrowth or both femoral and acetabular abnormalities, resulting in a loss of native hip biomechanics and pain upon hip flexion and rotation. Radiographic evidence can include loss of sphericity of the femoral neck (cam impingement) and/or acetabular retroversion with focal or global overcoverage (pincer impingement). Operative intervention is indicated in symptomatic patients after failed conservative management with radiographic evidence of impingement and minimal arthritic changes of the hip, with the goal of restoring normal hip biomechanics and reducing pain. This is done by correcting the femoral head-neck relationship to the acetabulum through femoral and/or acetabular osteoplasty and treatment of concomitant hip pathology. In pincer impingement cases with small lunate surfaces, reverse periacetabular osteotomy is indicated as acetabular osteoplasty can decrease an already small articular surface. While surgical dislocation is regarded as the traditional gold standard, hip arthroscopy has become widely utilized in recent years. Studies comparing both open surgery and arthroscopy have shown comparable long-term pain reduction and improvements in clinical measures of hip function, as well as similar conversion rates to total hip arthroplasty. However, arthroscopy has trended toward earlier improvement, quicker recovery and faster return to sports. The purpose of this study was to review the recent literature on open and arthroscopic management of FAI.

Diagnostic Accuracy of Clinical Tests and Imaging Exams for Femoroacetabular Impingement: An Umbrella Review of Systematic Reviews

OBJECTIVE

To synthesize available evidence about diagnostic accuracy of clinical tests and imaging examinations for femoroacetabular impingement (FAI) syndrome.

DESIGN

Umbrella review.

SETTING

N/A.

PARTICIPANTS

N/A.

INTERVENTIONS

N/A.

MAIN OUTCOME MEASURES

Systematic reviews (SR) indexed in Embase, LIVIVO, PubMed, SCOPUS, the Cochrane Library, and Web of Science were searched in a 2-phase process. SR assessing diagnostic accuracy were considered eligible.

RESULTS

From 1520 studies, 6 SR were included, which evaluated 24 primary studies related to FAI syndrome. Of these, 5 SR assessed clinical tests, and a substantial heterogeneity was found concerning reference standards adopted across primary studies, which included arthroscopy, clinical examination (associated or not with imaging exams), intra-articular injections, and open surgery. Most clinical tests presented higher values of sensitivity compared with specificity, although evidence was considered limited because the same primary studies were often included across SR. Nonetheless, evidence around the flexion adduction internal rotation (FADIR) test was considered stronger and its use as a screening tool was consistently supported. Only one SR assessed the accuracy of imaging examinations, which adopted open surgery as the sole reference standard. Most imaging exams presented considerably high values of sensitivity, although specificity values were notably lower.

CONCLUSIONS

No robust recommendations can be provided for most clinical tests, although the FADIR test, in particular, was consistently supported as a screening tool. Moreover, although imaging examinations showed considerably high sensitivity values, evidence was considered sparse and further research is strongly recommended to validate its use as reference standards for diagnostic accuracy data.

Hip arthroscopy is a successful treatment for femoroacetabular impingement in under-16 competitive football players: a prospective study with minimum 2-year follow-up

INTRODUCTION

Femoroacetabular impingement is considered a spectrum disease affecting multiple hip structures and it is especially prevalent in football players. Hip arthroscopy has shown good results in this population. However, little attention has been given to its efficacy in children and adolescent players. The aim of this study is to evaluate the outcomes of hip arthroscopy in under-16 football players.

MATERIALS AND METHODS

Between 2008 and 2019, all under-16 competitive football players who underwent hip arthroscopy for the treatment of femoroacetabular impingement were recruited for this prospective study. Hip pain and function were measured through the VAS, HOS, mHHS and WOMAC scores before the surgery, at 1-year after the surgery and at minimum 2-years after surgery. Preoperative and postoperative scores were compared to  establish the evolution of hip pain and function. Additionally, rate and time to return to play were recorded.

RESULTS

14 subjects were included in the analysis. All subjects attended to the last follow-up, at mean 3.21 years after the surgery (range 2-10). Mean ± SD VAS (0-100) scores were 60.14 ± 15.88 before the surgery, 6.43 ± 5.19 at 1-year follow-up and 5.07 ± 4.05 at final follow-up (p < 0.05). Significant improvements were observed in HOS ADL, HOS SS, mHHS and WOMAC (p < 0.05) between preoperative values and 1-year follow-up. No significant differences were found in knee pain or function between 1-year and final follow-up assessments (p > 0.05). All subjects (100%) were playing football 1-year after the surgery, with a mean ± SD time to return to play of 5.93 ± 2.09 months. 13 subjects (92.86%) were still playing at final follow-up.

CONCLUSIONS

Hip arthroscopy is a safe and effective surgical procedure for the treatment of FAI in under-16 competitive football players, improving hip pain and function with excellent rates to return to play.

Slipped Capital Femoral Epiphysis Associated With Athletic Activity

BACKGROUND

Little data exist regarding the association of slipped capital femoral epiphysis (SCFE) and sporting activities.

HYPOTHESIS

There is no association between SCFE and sporting activities.

STUDY DESIGN

Retrospective review of all SCFE cases at our institution from 2010 through March 2021.

LEVEL OF EVIDENCE

Level 3.

METHODS

All patients with idiopathic SCFE were reviewed looking for the presence/absence of sporting activities and symptom onset. Also collected were the age, symptom duration, and weight/height of the patient, sex, race, and stable/unstable nature of the SCFE. The severity of the SCFE was measured using the lateral epiphyseal-shaft angle.

RESULTS

There were 193 children (110 boys, 83 girls) with idiopathic SCFEs. The SCFE was stable in 147, unstable in 45, and unknown in 1. The average age was 12.1 ± 1.8 years, average SCFE angle 38° ± 20° and symptom duration 4.0 ± 5.1 months. An association with a sporting activity was present in 64 (33%). The sporting activity was basketball (18), football (11), baseball/softball (10), and others (23). Football, basketball, and soccer predominated in boys, baseball and running sports were equal between boys and girls, and cheerleading/gymnastics/dancing predominated in girls. Differences showed that those involved in sports had a slightly lower body mass index (BMI) (88th percentile vs 95th percentile, P = 0.00). There were no differences between those involved and those not those involved in sporting activities for symptom duration, SCFE severity, sex, race, or stable/unstable SCFE type.

CONCLUSION

Sporting activities are associated with the onset of symptoms in 1 of 3 of patients with SCFE, refuting the null hypothesis.

CLINICAL RELEVANCE

A high level of suspicion for SCFE should be given when any peripubertal athlete presents with hip or knee pain regardless of BMI/obesity status, and appropriate imaging performed.

Cam Morphology Is Associated With Increased Femoral Version: Findings From a Collection of 1,321 Cadaveric Femurs

BACKGROUND

To evaluate the relationship between femoral version (FV) and α angle (AA) in a large osteological collection of human femurs.

METHODS

The University of Iowa-Stanford osteological collection was used to evaluate the research aims. To measure FV and AA, axial photographs of the proximal femurs were taken, referenced from the posterior condylar axis. FV and AA measurements were obtained using ImageJ software, and the relationship between FV and AA was assessed with repeated-measures analysis of variance and generalized linear models. A P value of <.05 was considered statistically significant.

RESULTS

A total of 1321 cadaveric femurs (666 left and 655 right) in 721 cadavers were examined. The average AA for all femurs was 47.8° ± 10.9°, and the average FV for all femurs was 8.53° ± 8.09°. Overall, 191 femurs (14.5%) exhibited cam morphology (AA ≥ 60°). Of the 721 cadavers, 600 had both femurs available for side-to-side comparison. The average FV of femurs with cam morphology was significantly higher than that of femurs without cam morphology (11.70° ± 8.82° vs. 7.99° ± 8.82°, P < .001). Linear regression analysis demonstrated that increased AA was significantly correlated with increased FV (β ± standard error of the mean = 0.21 ± 0.02, P < .0001).

CONCLUSION

In a large osteological collection of human femurs, a significant positive relationship between AA and increasing FV was identified.

CLINICAL RELEVANCE

FAI and hip impingement morphology are more complex than cam or pincer morphology. Cam morphology with high femoral anteversion may allow for normal or near-normal hip mechanics without impingement, and this may partially explain the high rates of asymptomatic cam-type femoroacetabular impingement (FAI) morphology in active and general populations. Given the multiple morphological factors implicated in the development of FAI syndrome, these findings warrant further investigation.

Biomechanics of Cam Femoroacetabular Impingement: A Systematic Review

PURPOSE

To assess how biomechanical gait parameters (kinematics, kinetics, and muscle force estimations) differ between patients with cam-type femoroacetabular impingement (FAI) and healthy controls, through a systematic search.

METHODS

A systematic review of the literature from PubMed, Scopus, and Medline and EMBASE via OVID SP was undertaken from inception to April 2020 using PRISMA guidelines. Studies that described kinematics, kinetics, and/or estimated muscle forces in cam-type FAI were identified and reviewed.

RESULTS

The search strategy identified 404 articles for evaluation. Removal of duplicates and screening of titles and abstracts resulted in full-text review of 37 articles, with 12 meeting inclusion criteria. The 12 studies reported biomechanical data on a total of 173 cam-FAI (151 cam-specific, 22 mixed-type) patients and 177 healthy age-, sex-, and body mass index-matched controls. Patients with cam FAI had reduced hip sagittal plane range of motion (mean difference -3.00° [-4.10, -1.90], P < .001), reduced hip peak extension angles (mean difference -2.05° [-3.58, -0.53] , P = .008), reduced abduction angles in the terminal phase of stance, and reduced iliacus and psoas muscle force production in the terminal phase of stance compared to the control groups. Cam FAI cohorts walked at a slower speed compared with controls.

CONCLUSIONS

In conclusion, patients with cam-type FAI exhibit altered sagittal and frontal plane kinematics as well as altered muscle force production during level gait compared to controls. These findings will help guide future research into gait alterations in FAI and how such alterations may contribute to pathologic progression and furthermore, how such alterations can be modified for therapeutic benefit.

LEVEL OF EVIDENCE

Systematic review of Level III studies.

Activity Level and Sport Type in Adolescents Correlate with the Development of Cam Morphology

The purpose of this study was to evaluate the influence of the volume and type of sport on the development of cam-type femoroacetabular impingement and acetabular dysplasia.

Clinical Measures of Pelvic Tilt in Physical Therapy

Pelvic tilt refers to the spatial position or motion of the pelvis about a frontal horizontal axis on the rest of the body in the sagittal plane. It is relevant for several musculoskeletal conditions commonly seen in physical therapist practice, particularly conditions affecting the hip and groin. Despite the relevance of pelvic tilt identified in biomechanical studies, and the historical precedence for assessing pelvic tilt, there is a lack of clarity regarding the utility of clinical measures that are practical in a rehabilitation setting. There are several options available to assess pelvic tilt which are discussed in detail in this commentary. All of these options come with potential benefits and considerable limitations. The purpose of this commentary is to provide an overview of the relevance of understanding pelvic tilt in the pathology and rehabilitation of conditions affecting the hip joint, with a focus applying evidence towards identifying clinical measures that may be useful in the rehabilitation setting and considerations that are needed with these measures.

LEVEL OF EVIDENCE

5.

Parameters affecting baseline hip function in patients with cam-derived femoroacetabular impingement syndrome: data analysis from the German Cartilage Registry

BACKGROUND

Using the database of the German Cartilage Registry (KnorpelRegister DGOU), this study aims to present patient- and joint-related baseline data in a large cohort of patients with cam-derived femoroacetabular impingement syndrome (FAI) and to detect symptom-determining factors.

MATERIALS AND METHODS

Requiring cam morphology as the primary pathology, 362 patients were found to be eligible for inclusion in the study. The assessment of preoperative baseline data was performed using the patient-reported outcome measure-International Hip Outcome Tool (iHOT-33). Descriptive statistics were performed to present baseline data. Univariate and multiple regression with post hoc testing were used to identify patient- and joint-related factors that might affect the preoperative iHOT-33 and its subscores, respectively.

RESULTS

The study collective's mean age was 36.71 ± 10.89 years, with 246 (68%) of them being male. The preoperative mean iHOT-33 total was 46.31 ± 20.33 with the subsection "sports and recreational activities" presenting the strongest decline (26.49 ± 20.68). The parameters "age," "sex," "body mass index" (BMI), and the confirmation of "previous surgery on the affected hip" were identified to statistically affect the preoperative iHOT-33. In fact, a significantly lower mean baseline score was found in patients aged > 40 years (p < 0.001), female sex (p < 0.001), BMI ≥ 25 kg/m² (p = 0.002) and in patients with previous surgery on the affected hip (p = 0.022). In contrast, the parameters defect grade and size, labral tears, and symptom duration delivered no significant results.

CONCLUSIONS

A distinct reduction in the baseline iHOT-33, with mean total scores being more than halved, was revealed. The parameters "age > 40 years," "female sex," "BMI ≥ 25," and confirmation of "previous surgery on the affected hip" were detected as significantly associated with decreased preoperative iHOT-33 scores. These results help to identify symptom-defining baseline characteristics of cam-derived FAI syndrome.

TRIAL REGISTRATION

The German Cartilage Registry is conducted in accordance with the Declaration of Helsinki and registered at germanctr.de (DRKS00005617). Registered 3 January 2014-retrospectively registered. The registration of data was approved by the local ethics committees of every participating institution. Primary approval was given by the ethics committee at the University of Freiburg (No. 105/13). https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00005617.

Genes associated with inflammation and bone remodeling are highly expressed in the bone of patients with the early-stage cam-type femoroacetabular impingement

BACKGROUND

Recent studies have shown high expression levels of certain inflammatory, anabolic, and catabolic genes in the articular cartilage from the impingement zone of the hips with femoroacetabular impingement (FAI), representing an increased metabolic state. Nevertheless, little is known about the molecular properties of bone tissue from the impingement zone of hips with FAI.

METHODS

Bone tissue samples from patients with early-stage cam-type FAI were collected during hip arthroscopy for treatment of cam-type FAI. Control bone tissue samples were collected from six patients who underwent total hip replacement because of a femoral neck fracture. Quantitative real-time polymerase chain reaction (PCR) was performed to determine the gene expression associated with inflammation and bone remodeling. The differences in the gene expression in bone tissues from the patients with early-stage cam-type FAI were also evaluated based on clinical parameters.

RESULTS

In all, 12 patients with early-stage cam-type FAI and six patients in the control group were included in this study. Compared to the control samples, the bone tissue samples from patients with FAI showed higher expression levels of interleukin-6 (IL-6), alkaline phosphatase (ALP), receptor activator of nuclear factor-kB ligand (RANKL), and osteoprotegerin (OPG) (P < 0.05). IL-1 expression was detected only in the control group. On the other hand, there was no significant difference in IL-8 expression between the patients with FAI and the control group. The patients with FAI having a body mass index (BMI) of >24 kg/m² showed higher ALP expression (P < 0.05). Further, the expression of IL-6 and ALP was higher in the patients with FAI in whom the lateral center-edge angle was >30° (P < 0.05).

CONCLUSIONS

Our results indicated the metabolic condition of bone tissues in patients with early-stage cam-type FAI differed from that of normal bone in the femoral head-neck junction. The expression levels of the genes associated with inflammation and bone remodeling were higher in the bone tissue of patients with early-stage cam-type FAI than in the patients with normal bone tissue.

Increased prevalence of femoroacetabular impingement on the elderly with fractures of the proximal femur

Objectives: Femoroacetabular impingement (FAI) has been recently related to several pathologies, besides chondral injury and hip arthritis. We aim to investigate the prevalence of FAI morphology in an elderly cohort hospitalized due to a proximal femur fracture and compare these findings to a control group. We hypothesize that limited medial rotation due to FAI’s morphology could increase stresses to the proximal femur, acting as a facilitating mechanism for fractures in this region. Therefore, a higher prevalence of FAI morphology would be present in the study group. Methods: A retrospective cross-sectional study was performed based on the analysis of radiographic images in AP and lateral views of the fractured hip. Firstly, we have set to measure FAI prevalence in an elderly cohort victimized by fractures of the proximal by measures of the alpha, Tönnis, and lateral center edge angles of a hundred consecutive patients hospitalized for proximal femur fractures. Secondly, we have analyzed the possible relationship between the FAI subtypes and the type of fracture. Finally, we have compared this sample’s data with that of a similar control cohort not affected by fracture. Results: The cohort in this study displayed a higher prevalence of pathological changes in the Tönnis, center-edge, and alpha angles with odds ratios of 3.41, 2.56, and 4.80, respectively (with statistical significance). There was also a significant relationship between cam-type FAI and intertrochanteric fractures, corroborating our initial hypotheses. Conclusions: This study demonstrated that a cohort of older patients affected by fractures of the proximal femur had an increased prevalence of radiographic signs of femoroacetabular impingement. Furthermore, this is the first study demonstrating a statistically significant relationship of cam-type FAI with intertrochanteric fractures, suggesting a possible cause and effect relationship.

Femoroacetabular Impingement of the Hip Joint – Literature Review

Introduction: In patients with painful hip joint, femoroacetabular impingement is a relatively frequently diagnosed condition. Study aim: The aim of the study was to present the anatomy, biomechanics and pathomechanism of femoroacetabular impingement, surgical diagnostics and treatment, as well as physiotherapeutic procedures, and to provide answers to the following questions: 1. What are the causes of femoroacetabular impingement development and what is its most common form? 2. What are the clinical and imaging diagnosis of femoroacetabular impingement based on? 3. What are the goals of physiotherapeutic treatment in the treatment of patients with postoperative femoroacetabular impingement? Material and method: Current professional literature was analysed based on a review of Internet databases, including Pubmed and Google Scholar. Results: From the abovementioned Internet databases, 30 items from the current profession-al literature on the analysed variables were identified. Conclusions: The reasons for the development of femoroacetabular impingement are com-plex, including developmental disorders of the hip joint or its chronic overload. Its most common form is mixed type. The basic imaging test used is anterior-posterior X-ray, while clinical assessment is based on anterior-posterior impingement test. Physiotherapy should be individually tailored and focused on improving range of motion and muscle strength of the hip joint.

Functional Condition of Patients after Unilateral Hip Arthroscopy in the Process of FAI-Femoroacetabular Impingement: A Case-Control Study and Preliminary Report

Introduction: Femoroacetabular impingement is a commonly recognized condition among people with hip pain. Aim: The aim of this study was to assess how arthroscopy and physiotherapy treatment influenced the quality of life and functional condition of patients after arthroscopic femoroacetabular impingement (FAI) surgery. Materials and methods: We examined 19 people for the study and included 12 (6 men and 6 women). Their mean age was 40.1 ± 9.7 years. Manual and digital goniometers were used for the range of motion (ROM) measurements, and a dynamometer for muscle strength was used. Results from the operated limb were compared to the nonoperated healthy limb. We examined the patient’s health and well-being using the Harris Hip Score (HHS) and Short-Form Health Survey (SF-36) scales. The mean follow-up period was 21.2 months. Results: The postsurgery mean range of motion for all movements was lower in the operated limb. Statistically significant differences between limbs in ROM were observed for flexion, abduction, extension, and external rotation. Muscle strength was comparable between hip joints, except extension and adduction, which were statistically significantly weaker. The mean strength of the hip flexors and internal rotators was higher in the operated limb. After surgery, 67% of patients returned to exercise at the same or higher level. The mean HHS results were good, with values of 88.00 ± 11.48. The SF-36 scores were >50. Conclusion: After surgery and physiotherapy of FAI, ROM remained lower in the operated limb. Flexion and rotations remained to cause pain. The strength of flexors and internal rotators improved, and there was a high rate of return to sport.