Anterior joint capsule of the normal hip and in children with transient synovitis: US study with anatomic and histologic correlation

PURPOSE: To study the anatomic components of the anterior joint capsule of the normal hip and in children with transient synovitis. MATERIALS AND METHODS: Six cadaveric specimens were imaged with ultrasonography (US) with special attention to the anterior joint capsule. Subsequently, two specimens were analyzed histologically. These anatomic findings were correlated with the US findings in 58 healthy children and 105 children with unilateral transient synovitis. RESULTS: The anterior joint capsule comprises an anterior and posterior layer, mainly composed of fibrous tissue, lined by only a minute synovial membrane. Both fibrous layers were identified separately at US in 98 of 116 (84%) hips of healthy subjects and in all hips with transient synovitis. Overall, the anterior layer was thicker than the posterior layer. In transient synovitis compared with normal hips, no significant thickening of both layers was present (P = .24 and .57 for the anterior and posterior layers, respectively). Normal variants include plicae, local thickening of the capsule, and pseudodiverticula. CONCLUSION: Increased thickness of the anterior joint capsule in transient synovitis is caused entirely by effusion. There is no US evidence for additional capsule swelling or synovial hypertrophy.     

强直性脊柱炎髋关节改变的X线、CT和MRI对比研究

目的 探讨强直性脊柱炎(AS)髋关节受累的影像表现,比较X线平片、CT和MRI显示AS髋关节受累的敏感度.方法 对55例AS患者行骨盆X线平片和MR检查,其中29例行髋关节CT检查.MR平扫均包括冠状面T1WI、T2WI、STIR、附加水激励的三维稳态快速梯度回波序列(3D-BTFE-WATS),其中24例同时行脂肪抑制T1WI增强检查.分析患者的影像资料,应用x2检验对X线平片、CT和MRI显示AS髋关节受累改变的敏感度进行分析.结果 55例AS患者110侧髋关节中,X线平片和MRI显示异常分别为13侧和85侧;X线平片改变包括关节面下骨侵蚀破坏13侧、关节间隙变窄4侧、韧带骨赘5侧;MRI显示关节面下骨侵蚀破坏31侧、关节间隙变窄4侧、关节少量积液80侧、骨髓水肿32侧、脂肪沉积28侧、韧带附着点炎21侧,24例行MR增强检查患者中19例见双侧滑膜异常强化.CT检查29例共58侧髋关节,CT在显示X线平片和MRI所显示的骨破坏同时,发现X线平片未能显示的10侧骨破坏和MRI未显示的1侧骨破坏.X线平片、CT、MRI显示异常分别为10.3％ (6/58)、27.6％ (16/58)和77.6％ (45/58),MRI显示髋关节受累的敏感度优于X线平片和CT(x2值分别为53.22和29.08,P值均＜0.05).MRI除显示X线平片和CT所能显示的慢性骨结构改变外,还发现X线平片和CT未能显示的急性炎症改变.结论 MRI能显示X线平片和CT不能显示的AS髋关节受累的急性炎症改变,滑膜炎所致的少量积液和滑膜异常强化是髋关节受累最常见的MRI表现.     

Standards for ultrasonographic measurements of the hip joint in Indian adults

Synovitis in the hip joint, in contrast to that in other limb joints, is extremely difficult to evaluate clinically. In the hip joint synovitis manifests as an increase in the distance between the iliofemoral ligament and the femoral neck. The present ultrasonographic study was undertaken in 110 healthy Indian adults to establish standards for the depth of the normal hip joint space in the normal Indian adult population. The shortest distance was 4 mm, the longest was 9 mm. The mean distance was 6.4 (S.D. 1.1) mm. The mean difference between the right and left hips was 0.42 (S.D. 0.49) mm. An age-specific reference curve with 95% confidence limits was constructed. No correlation was found between hip joint space and the subjects' height, weight, age or sex. It is concluded that a distance between the iliofemoral ligament and the femoral neck of more than 9 mm or a difference in measurement between the hips of 1 mm or more suggests an intracapsular effusion or active synovitis. These figures are at variance with the measurements obtained in studies on Western white populations.     

The validity of radiographic assessment of childhood transient synovitis of the hip

The diagnostic significance of some radiographic signs (abnormal hip 'joint space' and periarticular fat layers) as indicators of hip joint effusion or hip complaints without effusion was studied with ultrasonography and radiography in 47 children (58 examinations), of whom 40 had acute unilateral transient synovitis. It was found that 'joint depth' was not influenced by presence of intra-articular fluid collections; blurring and/or displacement of the periarticular fat pads medial and lateral to the hip joint occurred more frequently when joint effusion was present than in symptom-free hips or in painful hips without effusion. The radiographic signs provided, however, too low diagnostic accuracy to be of practical value. It is suggested that ultrasonography of the hip joint is a valuable means in obtaining a better definition of the diagnosis transient synovitis.     

Doppler sonography of the anterior ascending cervical arteries of the hip: evaluation of healthy and painful hips in children

OBJECTIVE: We evaluated the Doppler sonography of small feeding arteries to the femoral head in children. SUBJECTS AND METHODS: In a prospective study of 224 hips in 112 patients (mean age, 5 years 11 months), the anterior ascending cervical arteries of the hip were identified with color Doppler sonography. Subsequently, we measured the resistive index (RI) with pulsed Doppler sonography. RESULTS: In 61% (137/224) of hips, a Doppler signal could be obtained. In asymptomatic hips (n = 64), the mean RI was 0.58. In symptomatic hips, the definitive diagnoses and mean values of RI included transient synovitis (n = 31) and 0.92, Perthes' disease (n = 9) and 0.67, and miscellaneous (n = 5) and 0.68. In 28 symptomatic hips, no definite diagnosis could be determined and the complaints spontaneously disappeared during follow-up (mean RI, 0.57). We found no statistically significant difference in the RI of symptomatic versus asymptomatic hips, except in patients with transient synovitis (p < 0.001). In 11 hips with transient synovitis that were reexamined after 4-6 weeks, the RI returned to normal (0.57). The RI in symptomatic hips showed a positive correlation with the amount of effusion (r = 0.69, p < 0.001). In symptomatic and asymptomatic hips, we found no correlation with age (p = 0.9 and 0.1, respectively). CONCLUSION: The deep capsular vessels of the hip joint can be evaluated on Doppler sonography in more than 60% of hips. Also, the RI is age independent and correlates with the amount of effusion.     

Imaging features of iliopsoas bursitis

The aim of this study was firstly to describe the spectrum of imaging findings seen in iliopsoas bursitis, and secondly to compare cross-sectional imaging techniques in the demonstration of the extent, size and appearance of the iliopsoas bursitis as referenced by surgery. Imaging studies of 18 patients (13 women, 5 men; mean age 53 years) with surgically proven iliopsoas bursitis were reviewed. All patients received conventional radiographs of the pelvis and hip, US and MR imaging of the hip. The CT was performed in 5 of the 18 patients. Ultrasound, CT and MR all demonstrated enlarged iliopsoas bursae. The bursal wall was thin and well defined in 83% and thickened in 17% of all cases. The two cases with septations on US were not seen by CT and MRI. A communication between the bursa and the hip joint was seen, and surgically verified, in all 18 patients by MR imaging, whereas US and CT failed to demonstrate it in 44 and 40% of the cases, respectively. Hip joint effusion was seen and verified by surgery in 16 patients by MRI, whereas CT (4 of 5) and US ( n=12) underestimated the number. The overall size of the bursa corresponded best between MRI and surgery, whereas CT and US tended to underestimate the size. Contrast enhancement of the bursal wall was seen in all cases. The imaging characteristics of iliopsoas bursitis are a well-defined, thin-walled cystic mass with a communication to the hip joint and peripheral contrast enhancement. The most accurate way to assess iliopsoas bursitis is with MR imaging; thus, it should be used for accurate therapy planning and follow-up studies. In order to initially prove an iliopsoas bursitis, US is the most cost-effective, easy-to-perform and fast alternative.     

Sonography of hip joint in infective arthritis

The most important determinant of outcome of a hip infection is the delay between the onset of the infection and treatment. Transient synovitis, and septic and tubercular arthritis of the hip remain common diagnostic problems. Conventional radiographic examinations are of little help in early diagnosis. Computed tomography, scintigraphy and magnetic resonance imaging, though informative, are expensive and not universally available. Ultrasonography (US) of the hip was done in 50 patients to define sonographic anatomy, detect joint effusions and correlate sonographic features with the etiology of the disease. Even small collections of fluid could be detected with accuracy. Both hypo- and hyperechoic synovial fluid was seen in septic arthritis, but hyperechoicity and a thickened capsule were the most characteristic findings. Synovial fluid had mixed echogenicity in tubercular and transient synovitis. The use of other (invasive) imaging modalities can be minimized because US can be used not only to demonstrate effusions early in the disease but also the status of the intra-articular compartment, joint capsule, bony surface and adjacent soft tissues. Ultrasonography should be used more commonly to diagnose infective arthritis, and no patient should be subjected to arthrotomy or drainage if US has ruled out the presence of a fluid collection.     

髋关节暂时性骨质疏松的MRI诊断及临床综合治疗观察

目的探讨髋关节暂时性骨质疏松的MRI表现及临床综合治疗。方法搜集经MRI检查、临床治疗证实的6例髋关节暂时性骨质疏松患者进行回顾性分析,男4例,女2例,平均年龄22岁,女性患病时未在妊娠期。全部患者患病髋关节均表现为不同程度的突发急性疼痛或渐进性疼痛。临床采用静注复方丹参和/或口服复方丹参等活血化淤,改善微循环的治疗方法。结果患侧髋关节MRI表现为片状等低T1、长T2异常信号,脂肪抑制序列呈高信号,增强扫描病灶无强化;临床治疗3个月后疼痛明显减轻,6个月疼痛完全缓解,复查MRI病变完全消失。结论MRI对诊断髋关节暂时性骨质疏松有一定价值。     

色素沉着绒毛结节性滑膜炎的影像学诊断

目的:探讨色素沉着绒毛结节性滑膜炎(PVNS)的影像学表现。方法:回顾性分析14例经手术及病理证实的PVNS患者的X线平片、CT、MRI等影像学资料。结果:14例X线检查者均见关节囊肿胀,其中8例骨质受侵蚀,1例可见软组织肿块。8例CT检查均示关节囊肿胀,其中6例可见关节腔积液及周围骨质受侵蚀,2例见软组织肿块影,2例增强扫描者均可见强化的滑膜结节和增厚的滑膜。10例MR检查者弥漫型8例,局限型2例,均可见到关节囊肿胀及数量不等的增生滑膜绒毛结节,其中9例在增生滑膜内可见含铁血黄素沉着,呈长T1、短T2低信号,8例关节腔积液及骨质受侵蚀,3例见软组织肿块,3例增强扫描者示增厚的滑膜和结节明显强化。结论:MRI对色素沉着绒毛结节性滑膜炎诊断及鉴别诊断具有重要价值,是一种简单、无创、有效的检查手段。     

Soft tissue manifestations of early rheumatic disease: imaging with MRI

PURPOSE: The aim of this study was to evaluate typical magnetic resonance imaging (MRI) findings in early rheumatic diseases manifesting at the soft tissues of the hand using a retrospective analysis. MATERIAL AND METHODS: A total of 186 MRI examinations of patients with clinical suspicion of a rheumatic disease were evaluated in a consensus reading by two experienced radiologists. All imaging patterns were assessed with respect to their type and localization. Under blinded and non-blinded conditions diagnoses were correlated with final clinical diagnosis. RESULTS: The most frequent diagnoses were rheumatoid arthritis (RA, 45.7%) and psoriatic arthritis (PsA, 15.6%). The mean correlation between clinical and MRI diagnosis (r) was 0.75 in blinded and 0.853 in non-blinded reading (p <0.001). The following extra-articular imaging patterns were found: synovitis (59.1%), tendovaginitis (91.4%), dactylitis (14.5%), and bone marrow edema (18.3%). Only dactylitis was specific for a particular rheumatic disease (PsA; r=0.934; sensitivity 84.9%, specificity 82.4%). CONCLUSION: Inflammatory conditions of the hand can be reliably detected with MRI. In many cases the definite diagnosis can only be made when taking clinical, serological, and radiographic results into account (+13.7% increase of significance).     

Concentric joint space narrowing of the hip associated with hemosiderotic synovitis (HS) including pigmented villonodular synovitis (PVNS)

Concentric joint space narrowing of the hip is an expected radiographic finding in cases of inflammatory arthritis such as rheumatoid arthritis or sepsis. However, similar joint space narrowing is associated with chronic hemorrhagic conditions that produce hemosiderotic synovitis. Hemosiderotic synovitis results from chronic intraarticular bleeding such as occurs in pigmented villonodular synovitis, generalized bleeding diathesis, synovial hemangioma, and chronic trauma. Five hips in five patients with concentric joint space narrowing not associated with inflammatory arthritis or with hemophilia were reviewed clinically, radiographically, and pathologically. All patients had a hemosiderotic synovitis. The definitive diagnosis of pigmented villonodular synovitis was made pathologically in two cases that demonstrated nodular areas of giant cell proliferation, collagen production, and lipid-laden histiocytes on histologic samples.     

小儿髋关节一过性滑膜炎的超声诊断及中医治疗

目的:探讨B超检查在小儿髋关节一过性滑膜炎的诊断和中医疗效观察中的价值。方法:对53例髋关节一过性滑膜炎病例,在中医手法治疗与中药湿热敷治疗过程中,采用超声检查了解股骨颈颈前间隙的变化。结果:治疗一周后,有15例患儿股骨颈颈前间隙<6mm,两周后复查,仅3例患儿股骨颈颈前间隙>6mm,四周后所有病例恢复正常。讨论:通过超声检查,能准确测量股骨颈颈前间隙的宽度,直观评价中医疗法在少儿髋关节一过性滑膜炎治疗中的疗效。     

正常人和股骨头缺血性坏死的髋关节腔液体的MRI

目的 探讨正常人和股骨头缺血性坏死的髋关节腔液体的ＭＲＩ。材料与方法 ２５２个正常人及３１个股头缺血性坏死的髋关节。所有病例均作ＳＥ序列Ｔ１、Ｔ２加权,黄断位及冠状位扫描。所有股骨头缺血性坏死的髋关节加作冠状位脂肪抑制序列。结果 关节腔液体于Ｔ２加权和脂肪抑制序列冠状位扫描显示最清楚。于以上两个序列上,关节腔液一现比脂肪高的信号。关节腔液体分４级：０级,无液体;１级,少量液体;２级,液体达骨头周围     

Transient synovitis of the hip in children: role of US

Transient synovitis of the hip remains a common diagnostic problem for the clinician. The physical signs are not pathognomonic of the condition, and the classic technical examinations are of little help. Therefore, the authors retrospectively studied the value of hip arthrosonography in 46 children with clinical symptoms suggesting pathologic hip conditions. In 20 of the 21 patients with a final diagnosis of transient synovitis, articular effusion was detected on ultrasound (US). Conventional radiography showed an increased medial joint space in only eight of these patients. Increased echogenicity of the articular fluid was found in both transient synovitis and septic arthritis. The high sensitivity of US in detecting intraarticular fluid was demonstrated by cadaver studies.     

MR imaging of bone marrow edema and joint effusion in patients with osteonecrosis of the femoral head: relationship to pain

OBJECTIVE: Our aim was to determine the occurrence of bone marrow edema and joint effusion and their relationship to pain in patients with osteonecrosis of the femoral head on the basis of MR imaging. MATERIALS AND METHODS: There were 71 patients with osteonecrosis of the femoral head based on characteristic radiographic and MR imaging findings. All patients had surgical confirmation of the disease. Both hips were affected with osteonecrosis in 39 patients, whereas only one hip was involved in 31 patients. The last patient underwent an arthroplasty of one hip during the study and had only one hip imaged. We evaluated a total of 110 hips in this study, of which 98 were painful. We staged osteonecrosis of the femoral head, using the classification of Steinberg et al. The 31 unaffected hips served as controls. Bone marrow edema and joint fluid were evaluated on MR images. Bone marrow edema was defined as an ill-defined area of low signal intensity on T1-weighted images with corresponding high signal intensity on T2-weighted or inversion recovery images localizing to the femoral head, neck, and intertrochanteric region. The amount of joint fluid was graded from 0 to 3. RESULTS: The peak of bone marrow edema occurred in stage III disease (72%); its odds ratio was seven times greater than that for stage I osteonecrotic hips. Effusions of a grade greater than or equal to 2 were seen most often in stage III disease (92%), compared with 10% in the control hips. With an effusion, bone marrow edema was 12.6 times greater when the hip was painful than when it was not. CONCLUSION: Both bone marrow edema and joint effusions existed with a peak occurrence in stage III disease. Bone marrow edema seems to have a stronger association with pain than does joint effusion in osteonecrosis of the femoral head.     

Diagnosing infection in the failed joint replacement: a comparison of coincidence detection 18F-FDG and 111In-labeled leukocyte/99mTc-sulfur colloid marrow imaging.

The objectives of this study were to investigate (18)F-FDG imaging, using a coincidence detection system, for diagnosing prosthetic joint infection and to compare it with combined (111)In-labeled leukocyte/(99m)Tc-sulfur colloid marrow imaging in patients with failed lower extremity joint replacements. METHODS: Fifty-nine patients--with painful, failed, lower extremity joint prostheses, 40 hip and 19 knee--who underwent (18)F-FDG, labeled leukocyte, and bone marrow imaging, and had histopathologic and microbiologic confirmation of the final diagnosis, formed the basis of this investigation. (18)F-FDG images were interpreted as positive for infection using 4 different criteria: criterion 1: any periprosthetic activity, regardless of location or intensity; criterion 2: periprosthetic activity on the (18)F-FDG image, without corresponding activity on the marrow image; criterion 3: only bone-prosthesis interface activity, regardless of intensity; criterion 4: semiquantitative analysis--a lesion-to-background ratio was generated, and the cutoff value yielding the highest accuracy for determining the presence of infection was determined. Labeled leukocyte/marrow images were interpreted as positive for infection when periprosthetic activity was present on the labeled leukocyte image without corresponding activity on the marrow image. RESULTS: Twenty-five (42%) prostheses, 14 hip and 11 knee, were infected. The sensitivity, specificity, and accuracy of (18)F-FDG, by criterion, were as follows: criterion 1: 100%, 9%, 47%; criterion 2: 96%, 35%, 61%; criterion 3: 52%, 44%, 47%; criterion 4: 36%, 97%, 71%. The sensitivity, specificity, and accuracy of labeled leukocyte/marrow imaging were 100%, 91%, and 95%, respectively. WBC/marrow imaging, which was more accurate than any of the (18)F-FDG criteria for all prostheses, as well as for hips and knees separately, was significantly more sensitive than criterion 3 (P < 0.001) and criterion 4 (P < 0.001) and was significantly more specific than criterion 1 (P < 0.001), criterion 2 (P < 0.001), and criterion 3 (P < 0.001). CONCLUSION: Regardless of how the images are interpreted, coincidence detection-based (18)F-FDG imaging is less accurate than, and cannot replace, labeled leukocyte/marrow imaging for diagnosing infection of the failed prosthetic joint.     

Pigmented villonodular synovitis of the hip: review of radiographic features in 58 patients

Clinical and radiographic findings were retrospectively reviewed in a multicentric survey of 58 patients with histologically proven pigmented villonodular synovitis (PVNS) of the hip. The most common clinical features were mechanical pain (47 cases) and limitation of joint motion (47 cases). On plain films, a classic form with large and multiple lucencies was found in 36 cases, followed by an osteoarthritis-like form (9 cases), an arthritis-like form (8 cases), normal radiographic appearance (3 cases), osteonecrosis of the femoral head (one case) and joint destruction with acetabular protrusion (one case). Bilateral involvement of the hips was probable in two patients. In contrast to the knee, the hip showed a high prevalence of bony lesions and joint space narrowing. Although an uncommon disease, PVNS of the hip has to be considered when arthritis is associated with uncharacteristic clinical or radiographic findings.     

Limited effectiveness of sonography in revealing hip joint effusion: preliminary results in 21 adult patients with native and postoperative hips

OBJECTIVE: The object of this study was to determine the effectiveness of sonography in the detection of hip joint effusions in both native and postoperative adult hips using arthrocentesis as a gold standard. MATERIALS AND METHODS: Twenty-one consecutive patients with clinical suspicion of hip joint effusion were examined on sonography by one of five musculoskeletal radiologists with experience in musculoskeletal sonography. All 21 patients underwent diagnostic arthrocentesis (fluoroscopic in 16, sonographic in five) to confirm the presence or absence of joint effusion. A retrospective analysis of the sonograms was made to assess the size of the distention of the anterior joint recess (anteroposterior dimension) and the echogenicity (anechoic or other relative to muscle), and correlation was made to the presence or absence of joint effusion. RESULTS: Joint effusion was seen on diagnostic arthrocentesis in 10 (48%) of the 21 patients. Seven of the 21 patients had native hips and 14 had prior hip surgery. Retrospectively, no significant difference was found with regard to the size of the anterior recess distention (p = 0.34) or echogenicity (p = 0.2) when comparing the patients with and without joint effusion. CONCLUSION: Anterior recess distention and echogenicity could not reliably be used as an indicator of adult hip joint effusion, either in native or postoperative hips. Diagnostic arthrocentesis was necessary to establish or exclude the presence of hip joint effusion.     

膝关节色素沉着绒毛结节性滑膜炎MRI表现与病理对照分析

目的：探讨膝关节色素沉着绒毛结节性滑膜炎（PVNS）的MRI表现与病理变化的关系。方法：对20例膝关节PVNS的MRI影像进行回顾性分析,并与手术病理结果对照。结果：20例膝关节PVNS均为弥漫型,病理特征为滑膜增厚呈结节状或绒毛状,有丰富的血管和大量含铁血黄素沉着。MRI表现均有滑膜增厚、关节内软组织结节,T1WI呈等或低信号,T2WI呈低信号;均有不同程度关节积液;关节内脂肪垫受侵15例;半月板及交叉韧带受累10例;软骨或骨受侵16例。结论：MRI对膝关节PVNS有特征性表现,并敏感显示关节内外组织结构的侵犯程度及范围,MRI是诊断PVNS的理想检查方法。     

Capsular distance in the hip of the healthy child - normal values with sonography and MR imaging

PURPOSE: To determine the normal values of the anterior and posterior capsular distances of the hip joint in healthy children by means of US, using MR imaging as reference, and to evaluate any possible correlation between age, length, weight and anterior capsular distance (ACD). MATERIAL AND METHODS: In our first study both hips in 14 healthy children (5-18 years old) were examined with US and MR to obtain measurements of the ACD and the posterior capsular distance (PCD). The distance from the anterior or posterior aspect of the femoral neck to the anterior or posterior aspect, respectively, of the outer limit of the capsule was determined. The distances were measured both with the hips in spontaneous external rotation of 10-15 degrees and in internal rotation of 45 degrees. In our second study, both hips in 28 healthy children (3-16 years old) were examined with US to determine the ACD. Age, length and weight were recorded. RESULTS: Study I: There was good correlation between the US and MR measurements in all positions. The ACD measured by US was significantly increased in inward rotation of the hip. Study II: There was no correlation between ACD and age, length or weight. CONCLUSION: The PCD of the hip joint can be accurately measured by US with the hip in internal rotation of 45 degrees. When compared with MR values, the ACD measured by US was dependent on the degree of rotation of the leg and increased significantly in internal rotation. Because the outer limit of the external layer of the joint capsule is sonographically more distinct, we suggest that the capsular distance should be measured from the outer limit of the joint capsule to the anterior or posterior aspect of the femoral neck. The measurement should be made perpendicular to the femoral neck, at the position where the greatest numerical value is obtained.