The case of 'A Rhino Horn': case report and proposal for modification to the Hetsroni and Kelly classification.

Subspine impingement syndrome by definition involves a prominent antero-inferior iliac spine (AIIS) which can lead to impingement on the femoral neck thereby causing symptoms. We present the case of a 22-year-old semi-professional athlete who presented with a Type III AIIS morphology leading to subspine impingement syndrome and was managed via a mini open anterior approach. Radiological examination revealed a fairly prominent left AIIS resembling the 'horn of a rhino' extending to the trochanteric region anteriorly. A mini-anterior surgical approach was utilized for the resection of the 'rhino horn' and the rectus femoris was reattached. The patient remained asymptomatic at the one-year follow-up and had resumed weightlifting. Following this case, we propose a new classification of the type III AIIS morphology in view of the clinical presentation. The AIIS type III-Standard represents an extension from the acetabular rim to less than 1 cm (type III-S) and type III-Large, with an extension from the acetabular rim beyond 1 cm (type III-L). The type III-L will further be divided into two groups based on its relation to the ilium, type III-Lr ('rib shape') and type III-Lrh ('rhino horn')

Polyurethane Scaffold vs Fascia Lata Autograft for Hip Labral Reconstruction : Comparison of Femoroacetabular Biomechanics

The integrity of the acetabular labrum is critical in providing normal function and minimizing hip degeneration and is considered key for success in today's hip preservation algorithm. Many advances have been made in labral repair and reconstruction to restore the suction seal. To compare the biomechanical effects of segmental labral reconstruction between the synthetic polyurethane scaffold (PS) and fascia lata autograft (FLA). Our hypothesis was that reconstruction with a macroporous polyurethane implant and autograft reconstruction of fascia lata would normalize hip joint kinetics and restore the suction seal. Controlled laboratory study. Ten cadaveric hips from 5 fresh-frozen pelvises underwent biomechanical testing with a dynamic intra-articular pressure measurement system under 3 conditions: (1) intact labrum, (2) reconstruction with PS after a 3-cm segmental labrectomy, then (3) reconstruction with FLA. Contact area, contact pressure, and peak force were evaluated in 4 positions: 90º of flexion in neutral, 90º of flexion plus internal rotation, 90º of flexion plus external rotation, and 20º of extension. A labral seal test was performed for both reconstruction techniques. The relative change from the intact condition (value = 1) was determined for all conditions and positions. PS restored contact area to at least 96% of intact (≥0.96; range, 0.96-0.98) in all 4 positions, and FLA restored contact area to at least 97% (≥0.97; range, 0.97-1.19). Contact pressure was restored to ≥1.08 (range, 1.08-1.11) with the PS and ≥1.08 (range, 1.08-1.10) with the FLA technique. Peak force returned to ≥1.02 (range, 1.02-1.05) with PS and ≥1.02 (range, 1.02-1.07) with FLA. No significant differences were found between the reconstruction techniques in contact area in any position (P >.06), with the exception that FLA presented greater contact area in flexion plus internal rotation as compared with PS (P =.003). Suction seal was confirmed in 80% of PSs and 70% of FLAs (P = .62). Segmental hip labral reconstruction using PS and FLA reapproximated femoroacetabular contact biomechanics close to the intact state. These findings provide preclinical evidence supporting the use of a synthetic scaffold as an alternative to FLA and therefore avoiding donor site morbidity

Estudio de la función del rodete acetabular en la biomecánica de la cadera: estudio cadavérico de la repercusión de la lesión y la reparación del rodete acetabular en la cinética articular de la cadera

Trabajo experimental en espécimen de cadera para valorar la repercusión de la lesión labral, parcial o completa, en la distribución de cargas de la superficie acetabular, así como el papel de la reconstrucción labral por reanclaje al reborde acetabular en la misma. Este trabajo implica el diseño y desarrollo previo de una bancada de prueba, el uso de tecnología de sensores piezoeléctricos para medir la presión intraarticular y la medición dinámica de las mismas en cinco especímenes anatómicos con preservación de estructuras cápsulo-labrales. Los resultados muestran una alteración de la presión máxima (presión de punta o de pico) así como un aumento del área de soporte de presión tras lesión labral parcial o completa (asumida como labrectomía), con una normalización tras reparación labral en todos los movimientos testados y en las distintas regiones acetabulares. Este estudio pone de relieve la importancia de la reconstrucción labral para preservar las presiones normales en la superficie articular, hecho de trascendental importancia en la prevención de un desarrollo artrósico.Cadaverical biomechanical study to evaluate the function of the hip labrum. Cinetic study of acetabular cartilage pressures after partial or complete labral tears and evaluation of the effect of labral reconstruction with bony reatachment. The study needed a design of a testing ring, use of pressure sensor technology and dinamic testing in 5 cadaveric specimens with preservation of capsulolabral structures. Results showed incresase in peak stress and pressure area with labral tears, partial or complete (assumed as labrectomy), and normalization with labral reatachment in all the movements tested and in the different acetabular geographical areas. This study demonstrate the importance of labral reconstruction to preserve normal pressures in the acetabular surface. That is very important in orther to avoid arthrosic degeneration

Estudio de la función del rodete acetabular en la biomecánica de la cadera: estudio cadavérico de la repercusión de la lesión y la reparación del rodete acetabular en la cinética articular de la cadera

Trabajo experimental en espécimen de cadera para valorar la repercusión de la lesión labral, parcial o completa, en la distribución de cargas de la superficie acetabular, así como el papel de la reconstrucción labral por reanclaje al reborde acetabular en la misma. Este trabajo implica el diseño y desarrollo previo de una bancada de prueba, el uso de tecnología de sensores piezoeléctricos para medir la presión intraarticular y la medición dinámica de las mismas en cinco especímenes anatómicos con preservación de estructuras cápsulo-labrales. Los resultados muestran una alteración de la presión máxima (presión de punta o de pico) así como un aumento del área de soporte de presión tras lesión labral parcial o completa (asumida como labrectomía), con una normalización tras reparación labral en todos los movimientos testados y en las distintas regiones acetabulares. Este estudio pone de relieve la importancia de la reconstrucción labral para preservar las presiones normales en la superficie articular, hecho de trascendental importancia en la prevención de un desarrollo artrósico.Cadaverical biomechanical study to evaluate the function of the hip labrum. Cinetic study of acetabular cartilage pressures after partial or complete labral tears and evaluation of the effect of labral reconstruction with bony reatachment. The study needed a design of a testing ring, use of pressure sensor technology and dinamic testing in 5 cadaveric specimens with preservation of capsulolabral structures. Results showed incresase in peak stress and pressure area with labral tears, partial or complete (assumed as labrectomy), and normalization with labral reatachment in all the movements tested and in the different acetabular geographical areas. This study demonstrate the importance of labral reconstruction to preserve normal pressures in the acetabular surface. That is very important in orther to avoid arthrosic degeneration

Basics in hip chondrolabral lesions and state of the art

Chondrolabral complex is a weak point along an histological transition zone. Most cartilage and labral lesions in the femoroacetabular impingement syndrome are located in this area. Different classifications are used to evaluate the severity and predict the prognosis of chondrolabral complex injuries. Acetabular Labrum Articular Disruption (ALAD) and Multicenter Arthroscopy of the Hip Outcomes Research Network (MAHORN) classifications are commonly used with a prognosis and treatment implication. Treatment of chondrolabral lesions detected on magnetic resonance imaging (MRI), should only be considered when clinical symptoms are presented. A wide range of treatment options include debridement with or without microfracture, repair or regenerate therapies. The future of hip joint preservation should be directed towards to the development of the treatment of chondrolabral injuries

Prevalence of morphological variations associated with femoroacetabular impingement according to age and sex: a study of 1878 asymptomatic hips in nonprofessional athletes

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

Correction to: The Lisbon Agreement on Femoroacetabular Impingement Imaging-part 1: overview.

The original version of this article, published on 14 May 2020, unfortunately contained a mistake

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Objectives Imaging diagnosis of femoroacetabular impingement (FAI) remains controversial due to a lack of high-level evidence, leading to significant variability in patient management. Optimizing protocols and technical details is essential in FAI imaging, although challenging in clinical practice. The purpose of this agreement is to establish expert-based statements on FAI imaging, using formal consensus techniques driven by relevant literature review. Recommendations on the selection and use of imaging techniques for FAI assessment, as well as guidance on relevant radiographic and MRI classifications, are provided. Methods The Delphi method was used to assess agreement and derive consensus among 30 panel members (musculoskeletal radiologists and orthopedic surgeons). Forty-four questions were agreed on and classified into five major topics and recent relevant literature was circulated, in order to produce answering statements. The level of evidence was assessed for all statements and panel members scored their level of agreement with each statement during 4 Delphi rounds. Either "group consensus," "group agreement," or "no agreement" was achieved. Results Forty-seven statements were generated and group consensus was reached for 45. Twenty-two statements pertaining to "Imaging techniques" were generated. Eight statements on "Radiographic assessment" and 12 statements on "MRI evaluation" gained consensus. No agreement was reached for the 2 "Ultrasound" related statements. Conclusion The first international consensus on FAI imaging was developed. Researchers and clinicians working with FAI and hip-related pain may use these recommendations to guide, develop, and implement comprehensive, evidence-based imaging protocols and classifications

The Lisbon agreement on femoroacetabular impingement imaging : part 2 : general issues, parameters, and reporting

Objectives Imaging assessment for the clinical management of femoroacetabular impingement (FAI) is controversial because of a paucity of evidence-based guidance and notable variability among practitioners. Hence, expert consensus is needed because standardised imaging assessment is critical for clinical practice and research. We aimed to establish expert-based statements on FAI imaging by using formal methods of consensus building. Methods The Delphi method was used to formally derive consensus among 30 panel members from 13 countries. Forty-four questions were agreed upon, and relevant seminal literature was circulated and classified in major topics to produce answering statements. The level of evidence was noted for all statements, and panel members were asked to score their level of agreement (0-10). This is the second part of a three-part consensus series and focuses on 'General issues' and 'Parameters and reporting'. Results Forty-seven statements were generated and group consensus was reached for 45. Twenty-five statements pertaining to 'General issues' (9 addressing diagnosis, differential diagnosis, and postoperative imaging) and 'Parameters and reporting' (16 addressing femoral/acetabular parameters) were produced. Conclusions The available evidence was reviewed critically, recommended criteria for diagnostic imaging highlighted, and the roles/values of different imaging parameters assessed. Radiographic evaluation (AP pelvis and a Dunn 45 degrees view) is the cornerstone of hip-imaging assessment and the minimum imaging study that should be performed when evaluating adult patients for FAI. In most cases, cross-sectional imaging is warranted because MRI is the 'gold standard' imaging modality for the comprehensive evaluation, differential diagnosis assessment, and FAI surgical planning