[Magnetic resonance imaging and magnetic resonance arthrography of the acetabular labrum: comparison with surgical findings]

Validity of Magnetic Resonance Imaging Measurement of Hip Labral Width Compared With Intraoperative Assessment

PURPOSE

To determine if magnetic resonance angiography (MRA) and/or magnetic resonance imaging (MRI) could accurately determine the width of the labrum.

METHODS

Consecutively enrolled patients between the ages of 18 and 65 indicated for hip arthroscopy for femoroacetabular impingement were included between December 2017 and June 2018. Inclusion criteria for preoperative MRIs included: MRI availability in picture archiving and communication system; performance on a 1.5T or 3T MRI or 3T MRA; and adequate quality and lack of labrum ossification. Intraoperative labral width measurements were taken at standardized locations using an established acetabular "clockface" paradigm. Measurement was performed using a calibrated probe. The labral width was defined as the distance from the labrum extended laterally from the acetabular rim. MRI measurements were taken by 2 blinded musculoskeletal fellowship-trained radiologists at the same positions. Measurements were made at the 11:30 o'clock position (indirect rectus) on coronal proton density (PD) sequence, at 3 o'clock position (psoas-U) on axial oblique PD sequence, and at 1:30 (a point halfway between the 2) on sagittal fat-suppressed PD. The surgeons were blinded to the radiologists' measurements and vice versa. Intraoperative and radiographic labral width measurements were compared using an intraclass correlation coefficients (ICC), absolute agreement, and 2-way random effects model. The 2 radiologists' measurements were compared for interrater reliability using the same ICC model.

RESULTS

Fifty-one patients were included (30 females, 26 right hips). Average labrum width at the 3:00, 11:30, and 1:30 o'clock positions by arthroscopic measurement were 5.8 mm (range; standard deviation, 2-8; ±1.4), 6.3 mm (2-10; ±1.5) and 6.0 mm (2-9; ±1.5), and by MRI were 6.3 mm (2-10; ±1.5), 6.7 mm (3-10; ±1.4), and 6.1 mm (2-9; ±1.6), respectively. When including all MRI modalities, ICC agreement between intraoperative assessment, and radiologist assessment at the 3:00 o'clock, 11:30, and point halfway between was 0.82 (P < .001), 0.78 (P < .001), 0.84 (P < .001), respectively. Radiologist interrater ICC agreement at the same points was 0.88 (P < .001), 0.93 (P < .001), and 0.88 (P < .001).

CONCLUSIONS

Strong agreement was found between radiologic and arthroscopic measurement of labrum width when using MRI, suggesting MRI is an accurate way to measure labral width. There was not a significant difference between different MRI modalities. Accurately measuring labral width preoperatively with MRI may aid in surgical decision making.

LEVEL OF EVIDENCE

Level II, diagnostic study.

[Labral pathologies of the hip joint]

Magnetic resonance imaging (MRI) of the hip joint is performed for the diagnostics of many clinical pathologies. For clarification of pathologies of the hip joint conventional MRI and MR arthrography are used. The use of MRI either with or without the intravenous administration of contrast material is performed to diagnose bone marrow lesions, necrosis of the femoral head, inflammatory and tumorous lesions affecting the hip joint and its components. After the intra-articular administration of a diluted solution of contrast material, which results in distension of the joint, MR arthrography is performed for the diagnosis of intra-articular pathologies, such as lesions of the labrum acetabulare, chondral lesions and free intra-articular bodies. In recent times, MR arthrography is carried out with continuous traction of the limb to be examined because this leads to a distension of the joint and its components and in this way particularly lesions of the labrum with involvement of cartilage can be visualized even better. This article gives an overview of MRI and the accuracy of detecting lesions of the labrum acetabulare and the influence on the therapeutic approach.

Hip arthroscopy after surgical hip dislocation: is predictive imaging possible?

PURPOSE

Our purpose was to study the sensitivity, specificity, and predictive values for hip adhesions, labral tears, and articular cartilage lesions in patients who had open treatment for femoroacetabular impingement, had persistent symptoms, and had both magnetic resonance arthrography (MRA) with radial slices and hip arthroscopy.

METHODS

Of 750 patients, 21 patients (6 male and 15 female patients; mean age, 28 years [range, 16 to 41 years]) with persistent groin pain after open osteochondroplasty and femoroacetabular impingement were included. The mean time between open osteochondroplasty and hip arthroscopy was 19 months (range, 4 to 79 months). At index surgery, patients had open osteochondroplasty of the femoral head-neck junction, as well as resection of the acetabular rim with reattachment of the labrum. All patients had preoperative MRA.

RESULTS

At hip arthroscopy, 1 tear of the labrum was verified on MRA. MRA showed in all patients adhesions between the neck of the femur and joint capsule, which were confirmed at arthroscopy and removed. Sensitivity of MRA for tears and adhesions was 100%; specificity, 100% and positive predictive value (PPV), 100%. For acetabular cartilage damage, sensitivity was 66.7%; specificity, 77.8%; and PPV, 63.6%. For femoral cartilage damage, sensitivity was 80%; specificity, 100%; and PPV, 20%. Postoperative alpha angles were significantly decreased. Of 21 patients, 3 had persisting groin pain.

DISCUSSION

Persistent groin pain after open osteochondroplasty of the hip could result from pathologic changes such as intra-articular adhesions with concomitant soft-tissue impingement. This pathology, as well as cartilage damage and labral tears, can be shown on MRA with radial slices.

CONCLUSIONS

Twenty-one patients with persistent groin pain after open osteochondroplasty of the hip had adhesions identified by MRA with radial slices. At hip arthroscopy, these adhesions were removed and 18 of 21 patients had relief of their symptoms.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Femoro-acetabular impingement: can indirect MR arthrography be considered a valid method to detect endoarticular damage? A preliminary study

To assess the effectiveness of indirect Magnetic Resonance arthrography (i-MRa) in the detection of chondral and labral lesions related to femoro-acetabular impingement (FAI) a series of 21 hip joints in 17 patients with a clinical diagnosis of FAI were examined either with standard MR imaging, i-MRa and direct-MR arthrography (d-MRa). Sensitivity and accuracy of i-MRa in detecting chondral, labral and tardive lesions were calculated and compared with standard MR. The agreement in detecting endoarticular damage between i-MRa and d-MRa and the interobserver agreement was assessed by K statistic (p<0.05). Finally the presence of trocanteric bursitis was evaluated. I-MRa showed higher values of both sensivity and accuracy than standard MR in detecting chondral damage, with an increase to 92% for the first item and 95% for the second. The same was noticed in labrum evaluation with an increase to 88% and 90% respectively. The level of agreement between i-MRa and d-MRa in detection of chondral lesions was excellent, substantial for the labral damage and absolute for early osteoarthritic changes. An excellent interobserver agreement resulted in detection of both chondral and labral damages with i-MRa. In 6 hips (28,5%) we also found the presence of peri-trochanteric soft tissue inflammation that indicated the possibility of extrarticular involvement in FAI. Indirect-MRa can be considered a valid method of assessing endoarticular damage related to FAI, in comparison to d-MRa. It should be performed instead of standard MR if d-MRa is not available.

MRI of hip osteoarthritis and implications for surgery

Osteoarthritis of the hip joint is caused by a combination of intrinsic factors and extrinsic factors. Different surgical techniques are being performed to delay or halt osteoarthritis. Success of salvage procedures of the hip depends on the existing cartilage and joint damage before surgery; the likelihood of therapy failure rises with advanced osteoarthritis. For imaging of intra-articular hip pathology, MR imaging represents the best technique because of its ability to directly visualize cartilage, superior soft tissue contrast, and the prospect of multidimensional imaging. This article gives an overview on the standard MR imaging techniques used for diagnosis of hip osteoarthritis and their implications for surgery.

[High-field and ultrahigh-field magnetic resonance imaging: new possibilities for imaging joints]

Whole-body MR tomography at 3 T is moving steadily from research into routine clinical practice. The most important advantage of high-field MRI is the higher signal to noise ratio, which allows acquisitions in the musculo-skeletal system with higher resolution within the same scan time. The imaging of small joints, the visualization of labral anatomy and pathology in the shoulder and hip joints, as well as cartilage imaging will benefit from higher resolution protocols. In addition to improved morphological imaging of articular cartilage, the higher sensitivity of 3 T allows the clinical use of advanced MR techniques of cartilage such as T1 and T2 mapping, diffusion and sodium imaging. The improved spectral resolution with the higher field may improve metabolic imaging of tumors of the skeleton and soft tissues.

Influence of femoroacetabular impingement on results of hip arthroscopy in patients with early osteoarthritis

To ascertain whether better results could be obtained using hip arthroscopy, we retrospectively reviewed the radiographic and clinical aspects of anterior femoroacetabular impingement in 43 patients diagnosed with early osteoarthritis with acetabular labral tears who previously had arthroscopic treatment. The average followup was 50 months. The patients were divided into two groups: patients who had no osteoarthritis seen on simple radiographs, but had degenerative changes of the labrum and cartilage seen on magnetic resonance arthrograms and arthroscopy, and patients who had osteoarthritic findings seen on simple radiographs. Both groups were examined retrospectively for signs of anterior femoroacetabular impingement at the acetabulum and proximal femur. Postoperative improvement was evaluated using the Japanese Orthopaedic Association pain score. Six of 21 patients in Group I and 12 of 22 of patients in Group II showed radiographic evidence of femoroacetabular impingement. The score improved from 0.76 preoperatively to 2.38 postoperatively in Group I and from 0.75 preoperatively to 1.90 postoperatively in Group II. Arthroscopic débridement produced improved results seen during short-term and midterm followups. However, in patients with femoroacetabular impingement the results were considered inadequate. We found that arthroscopic treatment of osteoarthritis of the hip fails if there is detectable femoroacetabular impingement.

Prevalence and location of acetabular sublabral sulci at hip arthroscopy with retrospective MRI review

OBJECTIVE

The objective of this prospective study was to determine the prevalence and location of acetabular sublabral sulci diagnosed as variants at hip arthroscopy and to provide a retrospective MRI review.

SUBJECTS AND METHODS

Two experienced hip arthroscopists noted the prevalence and location of acetabular labral sulci in 121 patients. The study population consisted of 57 males and 64 females with an average age of 43 years (range, 16-70 years). Of the 121 hip arthroscopies that showed sulci (22% of patients), correlation with the relevant MR studies (n = 27) was performed. Two radiologists who were aware of the arthroscopic findings reviewed the MR studies retrospectively, and agreement on imaging appearances was reached by consensus.

RESULTS

Arthroscopy revealed 30 sulci (25%) in 27 of the 121 patients. In those who had a single sulcus (25 patients), 11 (44%) were located anterosuperiorly, 12 (48%) posteroinferiorly, one (4%) anteroinferiorly, and one (4%) posterosuperiorly. The other two patients had more than one sulcus: one patient had one posterosuperior sulcus and one posteroinferior sulcus; and the other patient had one anterosuperior sulcus, one anteroinferior sulcus, and one posteroinferior sulcus. In total, of the 121 patients, the number and position of the sulci were 12 anterosuperior (10%), 14 posteroinferior (12%), two anteroinferior (2%), and two posterosuperior (2%). Of the 27 MR examinations, 24 were unenhanced and three studies were performed after intraarticular injection of gadolinium. In these 27 patients, a total of 30 sulci were detected at arthroscopy. On retrospective MR review of both the conventional and gadolinium-enhanced studies, nine (75%) of the 12 anterosuperior sulci could be visualized. Ten (71%) of the 14 posteroinferior sulci were also identified. Neither of the two anteroinferior sulci could be seen. Both of the posterosuperior sulci were evident. Of the conventional MR studies, of a potential of 27, 18 (70%) were identified on conventional imaging.

CONCLUSION

Sulci of the hip exist (22% of patients) and can be found at all anatomic positions (i.e., anterosuperior, anteroinferior, posterosuperior, and posteroinferior) of the hip. These sulci can be visualized on MRI with an accuracy of 70% using a nongadolinium technique.

Acetabular labral tears of the hip: examination and diagnostic challenges

The purpose of this clinical commentary is to provide an evidence-based review of the examination process and diagnostic challenges associated with acetabular labral tears of the hip. Once considered an uncommon entity, labral tears have recently received wider recognition as a source of symptoms and functional limitation. Information regarding acetabular labral tears and their association to capsular laxity, femoral acetabular impingement (FAI), dysplasia of the acetabulum, and chondral lesions is emerging. Physical therapists should understand the anatomical structures of the hip and recognize how the clinical presentation of labral tears is difficult to view isolated from other hip articular pathologies. Clinical examination should consider lumbopelvic and extra-articular pathologies in addition to intra-articular pathologies when assessing for the source of symptoms and functional limitation. If a labral tear is suspected, further diagnostic testing may be indicated. Although up-and-coming evidence suggests that information obtained from patient history and clinical examination can be useful, continued research is warranted to determine the diagnostic accuracy of our examination techniques.

Prognostic value of magnetic resonance arthrography for Czerny stage II and III acetabular labral tears

PURPOSE

To assess the intraobserver reliability and prognostic value of magnetic resonance arthrography (MRA) on the basis of postoperative outcome measures following arthroscopic acetabular labral debridement (partial limbectomy).

METHODS

Between January 1999 and November 2000, 24 patients (13 females, 11 males) with an average age of 37.1 years (range, 21 to 56 years) underwent hip arthroscopy for the treatment of presumed acetabular labral tears. All patients underwent preoperative MRA and/or magnetic resonance imaging (MRI); images were evaluated by a single musculoskeletal radiologist on 2 independent occasions. Hip arthroscopy was performed on all patients. Outcomes were assessed by means of the Modified Harris Hip Score (MHHS) and the Short Form-36 (SF-36) questionnaires, which were completed by patients an average of 24.1 months (range, 12 to 55 months) postoperatively. The accuracy of the initial read, as well as the prognostic value of the Czerny MRA classification system for stage II (intrasubstance tears) and stage III (complete avulsions) acetabular labral tears, was assessed.

RESULTS

Twenty-two of 23 tears (96%) were detected on the initial read. On the basis of intraoperative findings, 1 false-positive MRA, 1 false-negative MRA, and 1 incident of MRA overstaging were reported. On repeat interpretation, 23 of 23 (100%) tears were identified, and intraobserver reliability for recording the presence of a tear was excellent (kappa coefficient = 0.96). No difference was noted in outcomes between patients with or without arthroscopic evidence of chondromalacia (all P > .29), or between patients older or younger than 30 years (all P > .34). Likewise, no difference in outcome was seen between 15 patients with Czerny stage II tears revealed on MRA versus 9 patients with Czerny stage III tears (all P > .79).

CONCLUSIONS

MRA is sensitive and accurate for the detection of acetabular labral tears, with excellent intraobserver reliability. Arthroscopic partial limbectomy is successful in two thirds of patients. Patients with Czerny stage II and III tears do not appear to have significantly different outcomes following arthroscopic labral debridement.

LEVEL OF EVIDENCE

Level IV, prognostic case series.

Diagnosis and Management of Traumatic and Atraumatic Hip Instability in the Athletic Patient

Although relatively uncommon compared with the shoulder, hip instability can be a source of significant disability and is a commonly unrecognized injury. Hip instability can be traumatic or atraumatic in origin. Our understanding and treatment plan for hip instability due to traumatic events is well established. However, our understanding and treatment modalities for hip instability due to atraumatic events or repetitive motion in high level athletes are not as well defined. In this article, we will review the spectrum of traumatic and atraumatic hip instability and discuss the relevant anatomy, history, and physical examination findings, imaging studies, and treatment options with a focus on hip arthroscopy, and review of the literature.

3T MR Imaging of the Musculoskeletal System (Part II): Clinical Applications

The gain in SNR that is afforded by 3T MR imaging systems has tremendous clinical applications in the musculoskeletal system. The potential for demonstrating and enhancing the visibility of normal osseous, tendinous, cartilaginous, and ligamentous structures is exciting. Furthermore, harnessing this added signal to increase spatial resolution may improve our diagnostic abilities in various joints dramatically. Radiologists have enjoyed great success in assessing joint disease with current MR imaging field strengths; however, many intrinsic joint structures remain poorly evaluated, which leads to a golden opportunity for 3T MR imaging. The articular cartilage of the knee, the glenoid labrum of the shoulder, the intrinsic ligaments and TFC of the wrist, the collateral ligaments of the elbow, the labrum and articular cartilage of the hip, and the collateral ligaments of the ankle have been evaluated suboptimally on 1 .5T systems using routine nonarthrographic MR images. Because of the enhanced SNR, the higher spatial resolution, and the greater CNR of intrinsic joint structures at higher field strengths, 3T MR imaging has the potential to improve diagnostic abilities in the musculoskeletal system vastly, which translates into better patient care and management. The author's 2 years of clinical experience with musculoskeletal MR imaging on 3T systems has met and exceeded his expectations, and has bolstered the confidence of his orthopedic surgeons in his diagnoses. As coil technology advances and as the use of parallel imaging becomes more available in the extremities, the author expects to see even more dramatic improvements in image quality.

Evaluating hip labral tears using magnetic resonance arthrography: a prospective study comparing hip arthroscopy and magnetic resonance arthrography diagnosis

PURPOSE

To evaluate the sensitivity and accuracy of magnetic resonance arthrography (MRA) with true sagittal scout image mapped radial reformation in localizing hip labral tears.

TYPE OF STUDY

Case series.

METHODS

Thirty patients were examined with hip MRA because of suspected labral tears. Every patient underwent normal hip arthrography and MR examinations using a 1.5-T scanner with a 3D-FLASH pulse sequence. Multiplanar reformation using double oblique technique produced radial reformatted rotation images with 10 degrees increment on the acetabular rim. Labral tears were annotated as anterior-superior (AS), anterior-inferior (AI), posterior-superior (PS), and posterior-inferior (PI) quadrant based on the cranial-caudal axis in true sagittal reformatted scout localizing image. Patients with positive MRA findings were counseled to have the arthroscopic hip procedure.

RESULTS

Five patients showed no MRA indication of labral tear. Of 25 patients who had MRA evidence of labral tear, 17 underwent arthroscopic hip surgery. One patient had only synovial process in the hip joint near the suspected MRA area. The remaining 16 operated patients had labral tears with a total of 21 quadrant lesions on arthroscopy (distributed as AS, 14; AI, 3; PS, 2; and PI, 2). Radial reformatted images revealed accurate mapping with arthroscopic findings in 21 of the 22 quadrant lesions. The sensitivity and accuracy of MRA for the diagnosis of hip labral tear were 100% and 94%, respectively, and the sensitivity and accuracy of radial reformatted MRA for mapping the tear location were 100% and 96%, respectively.

CONCLUSIONS

MRA using radial reformatted images with a true sagittal localizer may achieve superior success rates in diagnosing hip labral lesions and in guiding the arthroscopist in portal selection, thus rendering location of hip labral tears simpler in surgery. It supplied detailed preoperative information to the surgeon, avoiding unnecessary surgery for patients if the diagnosis was unconfirmed.

LEVEL OF EVIDENCE

Level III.

Magnetic resonance imaging of the hip: detection of labral and chondral abnormalities using noncontrast imaging

PURPOSE

Traditional imaging techniques have limited ability to detect subtle chondral and labral injuries of the hip. We performed a retrospective review of patients who underwent magnetic resonance imaging (MRI) of the hip and subsequent hip arthroscopy in order to evaluate the ability of optimized, noncontrast MRI to identify tears of the acetabular labrum and defects in articular cartilage.

TYPE OF STUDY

Retrospective review of a consecutive sample.

METHODS

Between January 1997 and July 2000, 92 patients had MRI of the hip, followed by arthroscopic surgery of that hip by 1 of 2 surgeons (R.B., D.E.P.). Two musculoskeletal MR radiologists blinded to the initial MRI and surgical findings, independently interpreted the studies, looking for the location and degree of articular cartilage and acetabular labral pathology.

RESULTS

Of the 92 patients studied, each of 2 radiologists correctly identified 83 (94%) and 84 (95%) of the 88 labral tears present at surgery, respectively. There was 92% interobserver agreement on the MRI studies. For articular cartilage defects on the femoral head and acetabulum, there was good agreement (92% and 86% within 1 grade) between MRI and surgical grading and between the 2 MR readers (kappa of 0.8 for femoral head cartilage and 0.7 for acetabular cartilage).

CONCLUSIONS

This study shows that noncontrast MRI of the hip, using an optimized protocol, can noninvasively identify labral and chondral pathology. Such information may facilitate deciding which patients warrant surgical intervention, thus preserving hip arthroscopy as a therapeutic tool.

LEVEL OF EVIDENCE

Level II, Development of Diagnostic Criteria Study.

Sublabral Sulcus at the Posteroinferior Acetabulum:A Potential Pitfall in MR Arthrography Diagnosis of Acetabular Labral Tears

OBJECTIVE

Our study correlated findings on hip MRI and MR arthrography with hip arthroscopy to assess the location, prevalence, and potential pitfall of a normal acetabular sublabral sulcus.

MATERIALS AND METHODS

We retrospectively collected 58 hip MRI studies along with surgical reports in 58 patients who underwent hip arthroscopy over a 5-year period. Intraoperative photography (n = 23), radiography (n = 56), unenhanced MRI (n = 13), and MR arthrography (n = 54) studies were available for review. Two radiologists described hip anatomy on radiology studies with agreement by consensus.

RESULTS

A normal posteroinferior sublabral groove was confirmed on available arthroscopy photographs in four (17.4%) of 23 hips. In each of these four patients, the anatomic sublabral groove correlated with apparent partial labral detachment on MR arthrography. On review of all studies, 13 hips (22.4%) without a posterior labral tear at surgery had imaging findings of a sublabral sulcus. The sulcus was not associated with acetabular dysplasia, which was radiographically noted in 12 cases (21.4%). Preoperatively, the sulcus was misdiagnosed as a tear in two cases. Labral tears were anterior or anterosuperior in 51 patients.

CONCLUSION

A posteroinferior sublabral groove is a relatively common normal anatomic hip variation. If not recognized as normal, the sulcus may serve as a diagnostic pitfall on MR arthrography. Its location is distinct from most labral tears. We did not discover a sublabral sulcus at the anterior or anterosuperior acetabulum, the most common sites of labral injury.

Chondral degeneration and therapeutic hip arthroscopy

Therapeutic hip arthroscopy for the treatment of chondral degeneration remains controversial. A retrospective cohort study examined 70 patients of mean age 47 (range 22-87) years who had undergone hip arthroscopy and assessed them for evidence of chondral degeneration using radiological and arthroscopic means. Clinical outcome was assessed using a modified Farjo and Glick classification. Thirty-nine patients had evidence of chondral degeneration on arthroscopy with or without radiological diagnosis, and 31 had alternative pathology. If patients were found to have chondral degeneration at arthroscopy, they were significantly more likely to have a poor clinical result than if an alternative diagnosis such as a loose body or labral tear was made (p<0.0001). Patients with evidence of degenerative changes on plain hip radiographs were significantly more likely to have a poor clinical result following hip arthroscopy than patients with unremarkable hip radiographs (p<0.0001). Therapeutic hip arthroscopy for osteoarthritis should be used with caution, as a poor clinical result is significantly more likely compared to other pathologies such as a labral tear or loose body.

[Unusual "lipid cysts" in the acetabular labrum of patients with hip joint osteoarthrosis]

Diagnostic pathological examination of surgical specimens from patients with hip joint osteoarthrosis occasionally exhibits as yet undescribed pseudocysts consisting of folded granular membranes in necrotic or chondroid tissues. When stained with Sudan red, the content of these cysts indicates the presence of lipid substances. The presence of S100 protein-positive cells with intracytoplasmic fat vacuoles as well as such cells in the walls indicate that they develop from fat inclusions occurring in the chondroid cells of the labrum. Two different wall structures were detected by electron microscopy. The first type exhibited small walls of a granular material similar to the endoplasmic reticulum that surrounds intracytoplasmic fat globules. The second type consisted of broad layers of very tiny granules indicating a more advanced stage of the development of these cysts. The reason for the occurrence of these "chondrocytogenic lipid cysts" remains unknown-it may be assumed that they are due to mechanical labrum destruction that occurs in osteoarthrosis.

Hip arthroscopy: current indications, treatment options, and management issues

The management of hip injuries in athletes has evolved significantly in the past few years with the advancement of arthroscopic techniques. The application of minimally invasive surgical techniques has facilitated relatively rapid returns to sporting activity in both recreational and elite athletes. Recent advancements in both hip arthroscopy and magnetic resonance imaging have elucidated several sources of intraarticular abnormalities that result in chronic and disabling hip symptoms. Many of these conditions were previously unrecognized and, thus, left untreated. Current indications for hip arthroscopy include the presence of symptomatic acetabular labral tears, hip capsule laxity and instability, chondral lesions, osteochondritis dissecans, ligamentum teres injuries, snapping hip syndrome, iliopsoas bursitis, and loose bodies (for example, synovial chondromatosis). Less common indications include management of osteonecrosis of the femoral head, bony impingment, synovial abnormalities, crystalline hip arthropathy (gout and pseudogout), infection, and posttraumatic intraarticular debris. In rare cases, hip arthroscopy can be used to temporize the symptoms of mild-to-moderate hip osteoarthritis with associated mechanical symptoms. This article discusses the current clinical and radiographic methods to detect early hip joint disease and the current indications and surgical techniques of hip arthroscopy.

MR imaging of sports-related hip disorders

Hip arthroscopy is being used increasingly for the diagnosis and treatment of hip disorders. MR imaging performed with appropriate technical considerations may aid not only in preoperative planning but in the appropriate selection of patients, which tends to lead to better postoperative results. Although the painful hip is imaged most commonly by radiography, MR imaging is considered the next imaging test of choice for evaluation of most common hip abnormalities in athletes, including labral injuries, ligament injuries, osteochondral injuries, fractures, bursitis, and musculotendinous injuries. MR arthrography can be a particularly useful technique for dedicated assessment of hip joint internal derangements.