[Comparative study of ultrasound and magnetic resonance imaging in the diagnosis of asymptomatic anterosuperior acetabular labrum tears].

OBJECTIVE: To explore the diagnostic value of ultrasound for asymptomatic anterosuperior acetabular labral tears (ALT). METHODS: From August 2018 to February 2020, a total of 64 asymptomatic volunteers (101 hips) were recruited to complete 3.0T magnetic resonance imaging (MRI) and ultrasound examination. Among these asymptomatic volunteers, 31 were male and 33 were female, with the median age 35 (32, 39) years. Using 3.0T MRI findings as golden standard, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of ultrasound were calculated. RESULTS: The results showed the presence of unilateral or bilateral ALT in 33 (51.56%) asymptomatic vo-lunteers with a total of 47 hips (46.53%). Of the 37 asymptomatic volunteers with bilateral hip MRI examination, 14 had bilateral ALT and 8 had unilateral ALT. Of the 27 asymptomatic volunteers who underwent unilateral hip MRI, 11 had ALT. Of the 33 asymptomatic volunteers with labral tears, 11 were male and 22 were female, with 30 right hips and 17 left hips. The median age was 36 (33, 40) years in the ALT group and 34 (32, 38) years in the non-ALT group. There was no significant difference in age between the two groups (P > 0.05). In the asymptomatic population, the abnormal anterosuperior acetabular labrum manifestations on ultrasound were intra-labrum cleft in 26 cases, labral heterogeneous echogenicity in 25 cases, paralabral cysts in 2 cases, and labral focal hyperechoic area in 12 cases. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy for ALT diagnosed by ultrasound were 73.53%, 67.16%, 53.19%, 83.33% and 69.31%, respectively. The cross- sectional area (CSA) of the anterosuperior acetabular labrum was 0.20 (0.15, 0.24) cm2 in this study. The labral median CSA of the ALT group and non-ALT group were 0.22 (0.17, 0.28) cm2 and 0.17 (0.14, 0.21) cm2, respectively, with a statistically significant difference (P < 0.001). CONCLUSION: The ALT are common findings in asymptomatic volunteers on MRI. Intra-labrum cleft and labral heterogeneous echogenicity are common ultrasonographic signs in asymptomatic volunteers with ALT. The labra were more swollen in the asymptomatic volunteers with ALT compared to those without ALT.

MRI hip findings in asymptomatic professional rugby players, ballet dancers, and age-matched controls.

AIM: To investigate hip magnetic resonance imaging (MRI) findings in asymptomatic professional male rugby players and male ballet dancers compared to age-matched controls. MATERIALS AND METHODS: After ethics committee approval and consent from participants, 11 professional rugby players, 10 professional ballet dancers, and 10 controls completed activity and symptom questionnaires and underwent 3 T MRI of their self-declared dominant hip. Each scan was independently scored by two musculoskeletal radiologists for multiple features, including: joint morphology, acetabular labrum appearance, cartilage loss, and capsular thickness. Clinical and MRI features were assessed for variance by group using one-way analysis of variance (ANOVA) tests and Tukey post-hoc pairwise comparison of means. RESULTS: Labral tear prevalence was 87% with no significant difference between groups (p>0.05). Rates of paralabral cysts were significantly higher in ballet dancers (50%), compared to rugby players (0%) and controls (10%; p=0.01). Acetabular cartilage loss was present in 54% with no significant differences between groups. Superior capsular thickness was significantly greater in ballet dancers (5.3 mm) compared to rugby players (3.8 mm) and controls (3.8 mm; p=0.03). CONCLUSION: Despite the difference in type of activity between groups, there were equally high rates of labral tears and acetabular cartilage loss, questioning the role that sport plays in the development of these findings and their relationship to symptoms. The focally increased superior capsular thickness in ballet dancers may be an adaptive response to extreme ranges of movement.

Iatrogenic Articular Cartilage Injury in Arthroscopic Hip and Knee Videos and the Potential for Cartilage Cell Death When Simulated in a Bovine Model.

PURPOSE: To determine the incidence and characterize the severity of iatrogenic cartilage injuries. METHODS: Technique videos of arthroscopic femoral acetabular impingement procedures and meniscus repairs on VuMedi (n = 85) and Arthroscopy Techniques (n = 45) were reviewed and iatrogenic cartilage injuries were identified and graded (minor, intermediate, and major injury) by 2 independent reviewers. To demonstrate that even minor injuries on a cellular scale result in damage, a bovine osteochondral explant was used to create comparable minor iatrogenic injuries at varied forces that do not disrupt the articular surface (1.5 N, 2.5 N, and 9.8 N). Dead chondrocytes at the site of injury were stained with ethidium homodimer-2 and imaged with an Olympus FV1000 confocal microscope. χ2 tests were used for analysis; all results with P < .05 were considered significant. RESULTS: In total, 130 videos of arthroscopic meniscus and femoral acetabular impingement procedures were analyzed and the incidence of iatrogenic cartilage injury was 73.8%. There were 110 (70.0%) minor, 35 (22.3%) intermediate, and 11 (7.0%) major iatrogenic injuries. All forces tested in the minor injury bovine model resulted in chondrocyte death at the site of contact. CONCLUSIONS: Iatrogenic articular cartilage injuries are common in arthroscopy, occurring in more than 70% of the surgeon-published instructional videos analyzed. At least some chondrocyte death occurs with minor simulated iatrogenic injuries (1.5 N). CLINICAL RELEVANCE: The high rate of cartilage damage during arthroscopic technique videos likely under-represents the true incidence in clinical practice. Cell death occurs in the bovine minor injury model with minimal contact forces. This suggests iatrogenic cartilage damage during arthroscopy could contribute to clinical outcomes.

Clinical utility of virtual noncalcium dual-energy CT in imaging of the pelvis and hip.

Dual-energy virtual noncalcium images are increasingly used to identify marrow edema which accompanies bony pelvic injuries and marrow pathology obscured by cancellous bone. We present a clinical perspective of our experience using virtual noncalcium images in the work up of pelvic osseous pathology.

COMPARATIVE ANALYSIS OF WHOLE CARTILAGE TISSUE THERMOSTABILITY IN DISEASED PATIENTS VERSUS INJURED PATIENTS.

We conducted comparative thermodynamic analysis of femoral cartilages tissue of injured (healthy) patients and patients with congenital hip dislocation. It is shown, that temperature which corresponds to maximum of heat absorption peak of femoral cartilages tissue of diseased patient is on 6.4oC lower than heat absorption peak of femoral cartilages tissue of healthy patient. Heat absorbed during denaturation process in all these cases are close to each other with experimental error accuracy and corresponds to 52±2.6, 51±2.6 and 50±2.5 J/g of dried biomass accordingly. Analysis of the published data makes it possible to assert that the dominant heat absorption stage on DSC curves of tested fresh tissues samples is associated with melting of collagen fibers, hence the thermal stability of the collagen fibers in the patient's tissue is reduced relative to norm.

The iliotibial tract: imaging, anatomy, injuries, and other pathology.

The iliotibial tract, also known as Maissiat's band or the iliotibial band, and its associated muscles function to extend, abduct, and laterally rotate the hip, as well as aid in the stabilization of the knee. A select group of associated injuries and pathologies of the iliotibial tract are seen as sequela of repetitive stress and direct trauma. This article intends to educate the radiologist, orthopedist, and other clinicians about iliotibial tract anatomy and function and the clinical presentation, pathophysiology, and imaging findings of associated pathologies. Specifically, this article will review proximal iliotibial band syndrome, Morel-Lavallée lesions, external snapping hip syndrome, iliotibial band syndrome and bursitis, traumatic tears, iliotibial insertional tendinosis and peritendonitis, avulsion fractures at Gerdy's tubercle, and Segond fractures. The clinical management of these pathologies will also be discussed in brief.

Prevalence of the acetabular sublabral sulcus at MR arthrography in patients under 17 years of age: does it exist?

PURPOSE: To retrospectively determine characteristics of contrast-filled acetabular labral clefts in patients under the age of 17 years at MR arthrography (Mra) correlated with arthroscopy, which may impact the thinking regarding the existence of a sublabral sulcus. MATERIALS AND METHODS: After IRB approval, 41 patients under the age of 17 who had MRa were identified. The following observations of contrast-filled clefts were assessed: (1) presence/absence, (2) location, (3) depth, (4) abnormal signal within the labrum and (5) shape (linear, gaping, complex). Fisher's exact and the Wilcoxon matched-pairs signed-rank test were performed. Interreader agreement was calculated with Cohen's k. RESULTS: Reader 1 found clefts in 41 %. Depth was less than half in 6%, more than half in 65% and full thickness in 29%. Shape was linear in 53%, gaping in 18% and complex in 29%. Signal changes occurred in 88%. Reader 2 found clefts in 29%. Depth was less than half in 17%, more than half in 58% and full thickness in 25%. Shape was linear in 50%, gaping in 42% and complex in 17%. Signal changes occurred in 50%. None of the clefts fulfilled the criteria for a sublabral sulcus at MRa and arthroscopy. CONCLUSION: None of the clefts found in our subjects under the age of 17 years met the MRa and arthroscopy criteria for a sublabral sulcus, which supports the theory that such clefts represent labral tears.

Labral and cartilage abnormalities in young patients with hip pain: accuracy of 3-Tesla indirect MR arthrography.

OBJECTIVE: Assess the diagnostic accuracy of 3-T indirect magnetic resonance arthrography (iMRA) for hip cartilage and labral pathology detection using arthroscopy as the reference standard and compare it to the published performance of direct magnetic resonance arthrography (dMRA). MATERIALS AND METHODS: Between 2009 and 2011, 290 patients suspected of having femoroacetabular impingement underwent iMRA. Our study group consisted of 41 of these patients (17 males, mean age 35 years; 24 females, mean age 33 years) who did not have a prior history of hip surgery and who subsequently underwent arthroscopy. Two experienced musculoskeletal radiologists separately evaluated the randomized and anonymized studies for the presence and quadrant location of labral and cartilage pathology. These recorded data were compared to arthroscopic reports. RESULTS: Forty-one patients had labral pathology, 34 patients had acetabular and 5 patients had femoral cartilage pathology at arthroscopy. Sensitivity, specificity, accuracy, negative- and positive-predictive values for labral lesion detection were respectively 98, 99, 99, 99 and 98 %; for acetabular cartilage lesion detection they were 69, 98, 89, 87 and 95 %; for femoral cartilage lesion detection they were 69, 95, 93 and 39 %. Sensitivities of iMRA by quadrant (anteroinferior, anterosuperior, posteroinferior, posterosuperior) for the labrum were 100.0, 95.0, NA and 85.7 %, for acetabular cartilage were NA, 58.8, NA and 39.5 % and for femoral cartilage were 50.0, 33.3, 75.0 and 75.0 %). NA indicates results not available because of the absence of findings in those quadrants. Specificities of iMRA by quadrant (anteroinferior, anterosuperior, posteroinferior, posterosuperior) for the labrum (95.0, 100.0, 95.1, 67.5 %), acetabular (100.0, 85.7, 92.6, 79.5 %) and femoral cartilage (100.0, 94.7, 96.2, 85.9 %). CONCLUSION: iMRA at 3 T is accurate in detecting labral pathology suggesting that it is a viable alternative to dMRA.

Validation of a standardized mapping system of the hip joint for radial MRA sequencing.

OBJECTIVE: Intraarticular gadolinium-enhanced magnetic resonance arthrography (MRA) is commonly applied to characterize morphological disorders of the hip. However, the reproducibility of retrieving anatomic landmarks on MRA scans and their correlation with intraarticular pathologies is unknown. A precise mapping system for the exact localization of hip pathomorphologies with radial MRA sequences is lacking. Therefore, the purpose of the study was the establishment and validation of a reproducible mapping system for radial sequences of hip MRA. MATERIALS AND METHODS: Sixty-nine consecutive intraarticular gadolinium-enhanced hip MRAs were evaluated. Radial sequencing consisted of 14 cuts orientated along the axis of the femoral neck. Three orthopedic surgeons read the radial sequences independently. Each MRI was read twice with a minimum interval of 7 days from the first reading. The intra- and inter-observer reliability of the mapping procedure was determined. RESULTS: A clockwise system for hip MRA was established. The teardrop figure served to determine the 6 o'clock position of the acetabulum; the center of the greater trochanter served to determine the 12 o'clock position of the femoral head-neck junction. The intra- and inter-observer ICCs to retrieve the correct 6/12 o'clock positions were 0.906-0.996 and 0.978-0.988, respectively. CONCLUSIONS: The established mapping system for radial sequences of hip joint MRA is reproducible and easy to perform.

Use of MR arthrography in detecting tears of the ligamentum teres with arthroscopic correlation.

OBJECTIVE: To demonstrate the normal appearance of the ligamentum teres on MR arthrography (MRA) and evaluate the accuracy of MRA in detecting ligamentum teres tears with arthroscopic correlation. MATERIALS AND METHODS: Institutional Review Board approval was obtained with a waiver for informed consent because of the retrospective study design. A total of 165 cases in 159 patients (111 females, 48 males; mean age 41 ± 12 years) who underwent both MRA and hip arthroscopy were evaluated for appearance of the ligamentum teres, including the size, number of bundles, and ligamentum teres tears. Marrow edema of the fovea capitis adjacent to the ligamentum teres insertion and the presence of hip plicae were also recorded. RESULTS: The mean thickness and length of the ligamentum teres were 3.5 ± 1.5 mm and 25.2 ± 3.8 mm, respectively. Sensitivity, specificity, positive and negative predictive value, and accuracy of MRA for the detection of ligamentum teres tears were 78, 97, 74, 97, and 95%, respectively. CONCLUSION: MRA is an accurate method to evaluate the normal morphology and to detect tears of the ligamentum teres.

Usefulness of MR arthrography of the hip with leg traction in the evaluation of ligamentum teres injuries.

PURPOSE: To retrospectively evaluate the diagnostic accuracy of magnetic resonance (MR) arthrography of the hip with leg traction in the evaluation of ligamentum teres lesions and to evaluate whether there is increased articular distraction, possibly indicating secondary instability, in hips with ligamentum teres injuries. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained for this retrospective study. MR arthrograms of the hip with leg traction of 184 consecutive patients, including 108 men (mean age, 32.6 years; range, 19-53 years) and 76 women (mean age, 38.5 years; range, 18-56 years), who underwent hip arthroscopy were assessed for the presence of ligamentum teres lesions. The MR arthrographic findings were independently assessed by two radiologists who were blinded to the arthroscopic results. The inclusion criteria stipulated no previous surgery, arthroscopy within 1 month after MR arthrography, and availability of a detailed surgical report with ligamentum teres findings. The arthroscopy findings served as the reference standard. Sensitivity, specificity, accuracy, and K statistics for interobserver and intraobserver agreement were calculated. RESULTS: At arthroscopy, 32 ligamentum teres injuries were found. The ligamentum teres was normal in 152 (82.6%) patients and had suffered low-grade partial tears in 15 (8.1%) patients, high-grade partial tears in 10 (5.4%) patients, and complete ruptures in 7 (3.8%) patients. MR arthrography with axial traction demonstrated moderate sensitivity and high specificity for both low-grade (62/93%) and high-grade (66/96%) partial tears. Grouping low- and high-grade partial tears increased the diagnostic performance of MR arthrography, yielding a sensitivity of 87% and a specificity of 95%. For complete ligamentum teres tears, MR arthrography with leg traction demonstrated high sensitivity (92%) and specificity (98%). Articular distraction was significantly increased in patients with complete ruptures of the ligamentum teres (p = 0.001). CONCLUSION: MR arthrography with leg traction offers accurate diagnosis of ligamentum teres injuries. Patients with complete tears of the ligamentum teres exhibit increased articular distraction that may indicate secondary hip instability.

Application of the Goutallier/Fuchs Rotator Cuff Classification to the Evaluation of Hip Abductor Tendon Tears and the Clinical Correlation With Outcome After Repair.

PURPOSE: To assess the reliability and reproducibility of the Goutallier/Fuchs classification for the evaluation of abductor tendon tears of the hip, as well as to identify the relation between preoperative tear size, abductor muscle quality, and the success of endoscopic tendon repair. METHODS: This is a retrospective review of 30 consecutive endoscopic abductor tendon repairs performed by a single surgeon over a 2-year period. Preoperative magnetic resonance imaging scans were reviewed, and the muscle was assigned a grade according to the Goutallier/Fuchs classification. Patient-rated outcome scores--visual analog scale score, Hip Outcome Score (HOS), and modified Harris Hip Score (mHHS)--were collected preoperatively and at a minimum of 2 years postoperatively. Intraobserver and interobserver reliability for muscle grading was calculated. Postoperative outcome measures were compared with preoperative tear size, muscle grade, and repair type to assess for correlations. RESULTS: Of the 30 hips included in the study, over 75% were classified as grade 1 (n = 15) or grade 2 (n = 8). The intraobserver reliability and interobserver reliability of the classification system averaged 0.872 and 0.916, respectively. Two patients (grades 3 and 4) had repair failure and underwent muscle transfer. In the remaining 28 hips, improvement was seen in the visual analog scale score (6.0 v 1.7, P < .0001), HOS-Activities of Daily Living subscale score (58.8 v 83.4, P < .0001), HOS-Sport-Specific subscale score (40.0 v 75.0, P < .0001), and mHHS (55.6 points v 81.1 points, P < .0001) postoperatively. Increasing preoperative fatty infiltration and atrophy correlated with increased postoperative pain levels (regression coefficient, 0.93; P < .001) and decreased postoperative HOS-Activities of Daily Living subscale scores (regression coefficient, -3.36; P = .011), HOS-Sport-Specific subscale scores (regression coefficient, -5.63; P = .016), mHHS values (regression coefficient, -3.50; P = .0008), and patient satisfaction (regression coefficient, -1.04; P < .0001). Patient age, tear size, or repair type (double v single row) did not affect postoperative outcomes. CONCLUSIONS: The Goutallier/Fuchs classification system can be reliably and reproducibly applied to the evaluation of abductor tendon tears of the hip and appears to correlate with patient-rated outcomes after repair. Increasing preoperative muscle fatty atrophy correlates with increased patient pain and decreased patient satisfaction and functional outcomes after repair. LEVEL OF EVIDENCE: Level IV, prognostic case series.

Demystifying radial imaging of the hip.

The hip joint poses unique challenges at magnetic resonance (MR) imaging because of its shape and anatomic position. When conventional imaging planes are used, partial-volume averaging effects may substantially hamper the depiction of cartilage and labral damage at MR imaging. Such effects are most prevalent when the imaging plane is not perpendicular to the curvature of the joint and result in images that poorly depict or fail to depict cartilage and labral conditions. Partial-volume averaging, along with the inherently thin and closely apposed articular cartilage, may be partly to blame for the seemingly disparate reported sensitivities of MR imaging for depicting cartilage damage in the literature, which vary widely depending on whether arthrography was used. Fortunately, the multiplanar capability of MR imaging is not limited to standard anatomic planes. Radial sections, which are obtained perpendicular to the surfaces of the hip joint, provide a true cross section of the cartilage and labrum that conventional planes do not. Radial imaging is a reproducible technique that enhances the morphologic assessment of the articular cartilage and labrum. The additional information it provides is important because early damage occurs in the anterosuperior region of the hip in patients with femoroacetabular impingement.

Injury of the gluteal aponeurotic fascia and proximal iliotibial band: anatomy, pathologic conditions, and MR imaging.

The fascia lata, or deep fascia of the thigh, is a complex anatomic structure that has not been emphasized as a potential source of pelvic and hip pain. This structure represents a broad continuum of fibrous tissue about the buttock, hip, and thigh that receives contributions from the posteriorly located aponeurotic fascia covering the gluteus medius muscle and from the more laterally located iliotibial band (ITB). At the pelvis and hip, the ITB consists of three layers that merge at the lower portion of the tensor fasciae latae muscle. The gluteal aponeurotic fascia and ITB merge at the buttock and hip before extending inferiorly to the Gerdy tubercle at the anterolateral tibia. Injuries to these anatomic structures are an underdiagnosed cause of pain and disability and may clinically mimic more common processes affecting the hip and proximal thigh. Categories of disease include overuse injuries, traumatic injuries, degenerative lesions, and inflammatory lesions. Familiarity with the anatomy and pathologic conditions of the fascia lata and its components is important in their recognition as a potential source of symptoms. This article illustrates the anatomy of this complex fascia through anatomic-pathologic correlation and describes the magnetic resonance imaging appearances of the pathologic conditions involving it.

Imaging of the acetabular labrum.

The evaluation and proposed relevance of acetabular labral tears has rapidly evolved over the last decade due to the recognition of femoroacetabular impingement, an increase in the number of surgical options, and improved imaging of the hip with MR arthrography and 3-T MR protocols. The acetabular labrum, stabilizing the hip joint, provides a seal, enhancing fluid lubrication, maintains synovial pressure, and prevents direct contact of the articular surfaces. The labrum takes on a weightbearing role at the extremes of motion with excessive forces seen in a great number of athletic activities thought to contribute to tearing. Approximately 25% of labral tears are not associated with any specific injury or traumatic event with the underlying etiology thought to be repetitive microtrauma. This article reviews the anatomy of the acetabular labrum and discusses the five most commonly occurring etiologies of labral tears: trauma, femoroacetabular impingement, hip hypermobility, dysplasia, and degeneration. We also review the surgical and MR classification of labral tears and describe potential pitfalls in image interpretation.

Labral injuries of the hip in rowers.

BACKGROUND: Injuries of the hip in the adolescent and young adult athlete are receiving more attention with advances in the understanding of femoroacetabular impingement (FAI), labral pathology, and hip arthroscopy. Labral tears have not been well characterized in rowers. QUESTIONS/PURPOSES: The purposes of this study were (1) to describe the clinical presentation of labral pathology in rowers; (2) to describe the MRI and radiographic findings of labral pathology in rowers; and (3) to determine the likelihood that a rower with labral injury, treated arthroscopically, will return to sport. METHODS: We conducted a review from August 2003 to August 2010 to identify all rowers with MRI-confirmed intraarticular pathology of the hip presenting to our institution. Baseline demographics, symptoms and physical findings, and location of the labral tear with associated pathology, management, and early followup were recorded. The review yielded a total of 21 hips (18 rowers, three with bilateral labral pathology) with a mean patient age of 18.5 years (range, 14-23 years). Most of the rowers (85%) were female and the series included prep school (44%) and collegiate rowers (56%). Eighteen of the 21 hips (85%) eventually underwent arthroscopic surgery at our institution. RESULTS: A large majority of patients had isolated groin pain (71%) and physical findings consistent with impingement (81%). There was no single, dominant location for the labral tears on MRI. Among the 18 patients who had surgery, 10 (56%) returned to rowing, six (33%) never returned, and return data were not available for two (11%) at a mean of 8 months (range, 3-25 months) after surgery. CONCLUSIONS: The repetitive motions of the hip required for rowing may be a factor leading to intraarticular labral injuries in the athletes. Underlying anatomic abnormalities of the hip such as FAI may predispose certain patients to these injuries. However, many patients treated arthroscopically did not return to sport at a mean of 8 months after surgery.

The role of the acetabular labrum in hip dysplasia. A literature overview.

A periacetabular osteotomy (PAO) is the preferred joint preserving treatment for young adults with symptomatic hip dysplasia and no osteoarthritis. In symptomatic dysplasia of the hip, there is labral pathology in up to 90% of cases. However, no consensus exists as to whether a labral tear should be treated before the periacetabular osteotomy (PAO), treated simultaneously with the PAO, or left alone and only treated if symptoms persist after the PAO. This review is an update of aspects of labral anatomy and function, the etiology of labral tears in hip dysplasia, and diagnostic assessment of labral tears, and we discuss treatment strategies for coexisting labral tears and hip dysplasia.

Cross-sectional area of the labrum: role in the diagnosis of anterior acetabular labral tears.

OBJECTIVE: To investigate the utility of ultrasound cross-sectional area (CSA) measurements for diagnosing acetabular labral (AL) tears. METHODS: The study included qualitative/quantitative ultrasound examinations of 55 hips in 52 patients with a presumed diagnosis of AL tear and 56 hips in 28 healthy volunteers. MR arthrography examinations were available only for the patients and were reviewed for the presence of AL thickening and tear. RESULTS: The CSA of the anterior labrum was significantly larger in patients with an AL tear on MR arthrography than those in healthy volunteers (P < 0.01). The CSA cut-off value in determining labral thickening that maximises accuracy was 34.7 mm(2), and sensitivity, specificity and accuracy were 86.7%, 74.1% and 77.5%. Direct signs of AL tear on ultrasound had sensitivity, specificity and accuracy of 34.9%, 91.7% and 47.3%. The CSA cut-off value that maximises the accuracy of the AL tear was 40.6 mm(2), and sensitivity, specificity and accuracy were 58.1%, 91.2% and 78.4%. CONCLUSIONS: Ultrasound detects the thickened labrum frequently observed in MR arthrography studies, especially in patients with dysplastic hips. Although specificity of the method of detecting AL tears is high, sensitivity is low, with an overlap between subjects with AL tear and controls. KEY POINTS: • Labral degeneration is frequent in dysplastic hips • Thickened labra are frequently observed on MR arthrograms • Labral thickening can be depicted by quantitative ultrasound measurements • The sensitivity is low with overlap between subjects with AL tear and controls.

Acetabular rim lesions: arthroscopic assessment and clinical relevance.

PURPOSE: The purpose of this study was to investigate whether acetabular morphology may influence both pathogenesis and prognosis of the acetabular rim lesions and to propose a new system to classify labral tears. METHODS: We assessed radiographic and arthroscopic findings in 81 patients (40 male and 41 female patients, 86 hips) aged from 16 to 74 years (median, 31 years) who underwent hip arthroscopy. RESULTS: Acetabular rim lesions were associated with four different hip morphologies. Eleven (32 %) of 34 patients with severe rim lesions underwent hip arthroplasty for progressive symptoms, whereas no patient with early rim lesion reported significant progression of symptoms. The strategy of treatment was changed in 33 % of the patients undergoing arthroscopy before undertaking peri-acetabular osteotomy. CONCLUSIONS: Hip arthroscopy avoids more invasive procedures in patients with early acetabular rim lesions.

Acetabular Labral Tear with a Missed Posterior Wall Fracture in an Adolescent Athlete: A Case Report.

CASE: We present an adolescent contact-sport athlete presenting with hip pain after a traumatic in-play event. After delayed clinical improvement, a magnetic resonance arthrogram (MRA) revealed a posterior acetabular labral tear and the patient was referred for arthroscopic repair. However, subsequent critical interpretation of the MRA demonstrated a missed concomitant posterior acetabular wall fracture, which was later confirmed with computed tomography. CONCLUSION: Despite the low incidence of acetabular fractures in adolescents, this case report highlights the importance of maintaining clinical suspicion in young athletes after a traumatic injury, recognizing the association with labral tears, and acknowledging the limitations of certain imaging modalities.