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.     

US assessment of hip joint synovitis in rheumatic diseases. A comparison with MR imaging

PURPOSE: To assess the significance of ultrasonography (US) in detecting hip joint synovitis in patients with rheumatic diseases. MATERIAL AND METHODS: Forty patients with rheumatic disease and suspected hip joint synovitis underwent MRI and US of the hip joint. In addition to the throughout MRI evaluation, the anterior collum-capsule distance (CCD) was determined by both MRI and US. Thirteen healthy volunteers were examined with MRI to establish the criteria for normal findings in MRI when classifying hip joints to those with synovitis and those without. MRI was used as a gold standard. RESULTS: Synovitis was found using MRI in 31 hips of 22 patients (9 patients had bilateral synovitis). The intraclass correlation was 0.61 between MRI and US in measuring CCD. In classifying hip joint synovitis with US, the sensitivity of the method was 87% and specificity 42%, when the CCD criterion for synovitis was determined to be > or = 7 mm. If the cut-off point was raised to 9 mm, the sensitivity decreased to 61% while specificity increased to 94%. A difference in CCD of > or = 1 mm between the hips as an additional criterion for synovitis increased the number of false-positive findings. CONCLUSION: Measurement of CCD with US proved to be a rather inaccurate method to point out synovitis in rheumatic patients when using MRI as a reference. The main reason for this result was the thickened capsule, which US could not differentiate from a thickened synovium.     

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.     

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.     

Hip ultrasound

In newborns, US has an established role in the detection and management of developmental dysplasia of the hip. Later in childhood, when the limping child is a major diagnostic dilemma, US is extremely helpful in the identification of the varied disease processes underlying this condition, as transient synovitis, septic arthritis, Perthes disease and slipped femoral capital epiphysis. In adolescent practicing sporting activities, US is an excellent means to identify apophyseal injures about the pelvic ring, especially when avulsions are undisplaced and difficult-to-see radiographically. Later on, in the adulthood, US is an effective modality to diagnose tendon and muscle injuries about the hip and pelvis, identify effusion or synovitis within the hip joint or its adjacent bursae and guide the treatment of these findings. The aim of this article is to provide a comprehensive review of the most common pathologic conditions about the hip, in which the contribution of US is relevant for the diagnostic work-up.     

Sonography of the painful hip in children: 500 consecutive cases

Five hundred children with a painful hip or a limp were evaluated prospectively by plain films and sonography. The clinical, radiographic, and sonographic findings were correlated with the final diagnoses. Sonography disclosed hip effusion in 235 patients, and plain films were abnormal in 58 of these 235 patients and in four others. Both sonography and plain films were normal in 261 patients. No sonographic signs served to differentiate sterile, purulent, or hemorrhagic effusion. Follow-up sonograms were performed in 202 patients. Sonography showed that 73% of patients with presumed transient synovitis had no effusion 2 weeks after diagnosis. Patients with hip disorders other than transient synovitis had persistent effusion for more than 2 weeks; however, that was also observed in 27% of patients with presumed transient synovitis. Sonography was more sensitive than plain films for detecting hip effusion. However, sonographic detection of effusion changed the therapeutic approach in only six patients.     

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。     

Septic arthritis versus transient synovitis at MR imaging: preliminary assessment with signal intensity alterations in bone marrow

PURPOSE: To find any differential magnetic resonance (MR) imaging findings between septic arthritis and transient synovitis in pediatric patients. MATERIALS AND METHODS: The MR imaging findings in nine pediatric patients with septic arthritis and 14 with transient synovitis were retrospectively studied. The diagnoses were made by means of joint aspiration with bacteriologic study, arthrotomy, and clinical evaluation. MR imaging findings were analyzed with emphasis on the grade of joint effusion and alterations in signal intensity in the soft tissue and bone marrow of the affected hip joint. RESULTS: Signal intensity alterations in bone marrow (i.e., low signal intensity on fat-suppressed gadolinium-enhanced T1-weighted spin-echo images and high signal intensity on fat-suppressed T2-weighted fast spin-echo images) were seen in eight of nine patients with septic arthritis. These signal intensity alterations consisted of mild juxtaarticular changes in six patients without osteomyelitis and extensive changes in the femoral head and neck in two patients with coexistent osteomyelitis. Signal intensity alterations in bone marrow were not seen in the 14 patients with transient synovitis. CONCLUSION: Signal intensity alterations in the bone marrow of the affected hip joint are useful in the differentiation of septic arthritis from transient synovitis.     

小儿髋关节暂时性滑膜炎的彩色多普勒超声表现

目的:探讨彩色多普勒超声在小儿髋关节暂时性滑膜炎的临床价值。方法:选取髋关节暂时性滑膜炎患儿38例,应用彩色多普勒超声对患儿治疗前后髋关节滑膜内细小血管的血供情况和频谱多普勒进行血流检测评价。结果:患儿治疗前,肿胀组与积液组滑膜增厚型的病例患侧髋关节滑膜内血流信号较健侧明显丰富;肿胀组血流速度升高,积液组血流速度减低。治疗后1周,肿胀组及积液组患髋滑膜内的血流信号较治疗前有所下降;肿胀组血流速度减低,积液组血流速度升高。治疗后2周,两组患髋滑膜内血流信号基本同健侧。结论:多普勒超声能监测小儿髋关节暂时性滑膜炎髋关节滑膜内的血供改变,对疾病的诊断和疗效观察有重要的应用价值。     

Sport bei Hüftgelenkserkrankungen im Kindes- und Jugendalter

Children and adolescents suffering from hip disorders are often compromised in their physical activity and sports. The typical hip diseases in this age group are hip dysplasia, Perthes disease, Slipped Capital Femoral Epiphysis and transient synovitis of the hip. On the one hand athletic overuse can provoke hip symptoms and on the other hand sports activities need to be restricted in ongoing or past hip diseases. It is important to follow patients until growth arrest to recognize and possibly treat secondary hip deformities and early osteoarthritis.     

Synovial tissue of the hip at power Doppler US: correlation between vascularity and power Doppler US signal

PURPOSE: To correlate power Doppler ultrasonographic (US) findings of the vascularity of synovial tissue of the hip joint with the results of histopathologic examination of the same tissue to assess the value of power Doppler US in the visualization of synovitis. MATERIALS AND METHODS: The hip joints of 24 patients with osteoarthritis (n = 15) or rheumatoid arthritis (n = 9) of the hip joint were examined with US before arthroplasty. The vascularity of the synovial membrane was classified qualitatively by using power Doppler US. During surgery, a section of the synovial tissue examined at power Doppler US preoperatively was resected. The vascularity of the tissue specimen was investigated and graded qualitatively by a pathologist who was not aware of the US findings. Visual qualitative grading was controlled by means of analysis of the US images and histopathologic specimens with a digital image evaluation system. Correlations between power Doppler US and histopathologic examination findings were calculated by using Spearman rank correlation and Pearson correlation tests. RESULTS: The correlation between the qualitative power Doppler US results and the qualitative vascularity grades was 0.92 (P <.01, Spearman rho). The correlation between quantitative and qualitative results was 0.93 (P <.01, Spearman rho) for US imaging and 0.97 (P <.01, Spearman rho) for histopathologic examination. CONCLUSION: Study results showed power Doppler US to be reliable for qualitative grading of the vascularity of synovial tissue of the hip.     

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.     

Conventional radiography in transient synovitis of the hip in children

Conventional radiography was performed at diagnosis and at follow-up 5 to 9 months later in 70 children with transient synovitis of the hip. Twenty-four of the patients also had CT examination at diagnosis. The cartilaginous and osseous reaction in the conventional antero-posterior radiographs was studied as was the relation between the radiographic and CT findings concerning fat planes, joint effusion, and position of the hip joint. At diagnosis there was significant increase in the medial joint space and at follow-up examination there was significant increase in medial and cranial joint space, metaphyseal width and acetabular roof width. There was a correlation of a bulging lateral 'capsular fat plane' to the position of abduction in the affected hip which explains the asymmetry in the lateral fat plane observed in these patients.     

Coxitis fugax. The sonographic and radiologic picture in 65 cases

Sonography is a valuable technique for the detection of hip joint effusion in children with transient synovitis. In a retrospective study of 65 patients distension of the anterior recess was found to be increased by 2 mm or more in all patients investigated. A sonographic follow-up examination was carried out in 30 patients. These patients showed complete regression of hip effusion after 4 weeks. The importance of attention to sonographic changes of the adjacent bony outline and femoral head deformity in connection with other hip diseases is emphasized. In 45 patients in this study (62% of the cases) conventional radiography showed one or more indirect signs such as displacement, blurring or even obliteration of the fatty intermuscular planes or an increased joint space. In uncomplicated cases with clear sonographic and clinical findings a pelvic radiogram is unnecessary.     

The symptomatic hip in childhood: scintigraphic findings in the presence of a normal radiograph

The principal causes in children of a nonacute painful hip are Perthes disease and synovitis (irritable hip). The ^99mTc methylene diphosphonate (MDP) bone scan appearances in Perthes disease are well-known; in synovitis, the hip may show a diffuse increase in activity or may be normal. The significance of bone scintigraphy in the clinical setting of non-acute hip symptoms with normal skeletal radiography has been evaluated in 36 symptomatic children. The mean duration of symptoms prior to scan was 3 months (range 1 week-17 months). On the basis of final diagnosis, established by clinical findings, bone scan, X-ray and follow-up, the children were divided into two groups: synovitis or Perthes disease. Of the 33 scans in the 32 children with synovitis, 18 were normal and 15 showed diffusely increased activity on the painful side. All four patients with Perthes disease had focal femoral head abnormalities in the painful hip. Of the 18 children with normal scans, none went on to develop a skeletal disorder. In children with hip pain of over 1 week's duration, the main value of the bone scan is the early detection of Perthes disease. Diffuse increased activity on the painful side suggests synovitis. A normal scan virtually excludes significant skeletal abnormality.     

Ultrasonography in the study of synovial disorders and tendon lesions in rheumatoid arthritis

Conventional radiology is the main diagnostic tool for the visualization of osteoarticular lesions in rheumatoid arthritis. Articular effusions and popliteal cysts were examined with US. This paper is aimed at proving US capabilities in yielding important information about articular and peri-articular soft tissues in the early phases of rheumatoid arthritis. Over the last 30 months, the shoulder, wrist, hand, knee, and hip of 73 rheumatoid patients were studied by means of US and conventional and microfocal radiography. The patients were divided into 2 groups according to the time of onset of the disease. In group A, US demonstrated early synovial exudative inflammation, whereas conventional and microfocal radiography mainly demonstrated soft tissue swelling. In group B (where the first onset dated back to over 1 year), US demonstrated exudative and proliferative changes, together with recurrences. The authors believe US to be able to recognize the early changes of rheumatoid arthritis: as a matter of fact, US shows articular and periarticular soft tissues abnormalities and allows a differential diagnosis to be made between exudative and proliferative forms.     

The use of [18 F]fluorodeoxyglucose positron emission tomography to differentiate between synovitis,loosening and infection of hip and knee prostheses

Pain is a common unspecific symptom in orthopaedic prosthetics. The accurate differentiation between synovitis, loosening or infection is often difficult with conventional X-rays, arthrography or bone scintigraphy. Because of the high glucose uptake of inflammatory cells, [18F]fluorodeoxyglucose (18F-FDG) is an appropriate tracer for the evaluation of suspected inflammation or infection. In this preliminary study we describe 18F-FDG PET findings in patients referred for evaluation of painful hip or knee prostheses. We studied 23 patients with 28 prostheses, 14 hip and 14 knee prostheses, who had a complete operative or clinical follow-up. 18F-FDG PET scans were obtained with an ECAT EXACT HR+ PET scanner. High glucose uptake in the bone prostheses interface was considered as positive for infection, an intermediate uptake as suspect for loosening, and uptake only in the synovia was considered as synovitis. The imaging results were compared with operative findings or clinical outcome. PET correctly identified three hip and one knee prostheses as infected, two hip and two knee prostheses as loosening, four hip and nine knee prostheses as synovitis, and two hip and one knee prostheses as unsuspected for loosening or infection. In three patients covered with an expander after explantation of an infected prosthesis PET revealed no further evidence of infection in concordance with the clinical follow-up. PET was false negative for loosening in one case. Our preliminary results suggest that FDG PET could be a useful tool for differentiating between infected and loose orthopaedic prostheses as well as for detecting only inflammatory tissue such as synovitis.     

Ultrasound detects rapid progression of erosive disease in early rheumatoid arthritis: a prospective longitudinal study

Objective To evaluate and compare sequential ultrasound exams (US) with power-Doppler (PD) to radiography for the detection of synovitis and erosions in patients with early RA. Methods Radiographs and US with PD of the hands and feet were performed at baseline and 6± 2 months afterwards in 21 early RA patients. Their mean (range) age was 42.6 (21–81) years and the female/male ratio was 4:3; mean disease duration was 9 (1–28) months. Joints assessed were bilateral 2nd and 5th MCPs, 5th MTPs and the most swollen PIP in each hand, for a total of eight joints per patient. Radiographs (PA, lateral and pronated oblique) were read for erosions using the method of Sharp/van der Heijde. On US, erosions were defined as cortical defects greater than 2 mm in diameter with an irregular floor. Synovitis was rated as +1 (increase in joint fluid without synovial hyperemia), +2 (mild blood flow), +3 (moderate blood flow), and +4 (severe blood flow). Two blinded trained assessors read all images. Results US detected 15 erosions in 10 patients at baseline and 31 erosions in 12 patients on follow-up; radiographs could detect only one erosion at baseline and five erosions in three patients on follow-up. PD detected synovitis in all patients at baseline and on follow-up. Of the joints found to have synovitis, 64% were identified as such at baseline and 38% on follow-up. Conclusions Sequential US can determine disease progression in patients with early RA. Such data may allow the clinician to treat RA patients earlier in the hope of preventing joint damage. James A. Pittman General Clinical Research Center (GCRC) M01 RR-0032 from the National Center for Research Resources, National Institutes of Health.     

Ilio-psoas bursa enlargement.

The clinical and radiological features of 14 patients with ilio-psoas bursal enlargement associated with articular disease of the hip are presented. The condition primarily affects patients over the range of 50 years with pre-existing hip disease, usually of long duration. A clinical diagnosis before investigation was never made in our series as the symptoms were non-specific and varied, consisting of pain (40%), a palpable groin mass (40%) and lower limb swelling (28%). The diagnosis can be made pre-operatively and the extent along the path of the ilio-psoas accurately delineated. The bursal contents, although predominantly fluid in nature, do include a varying proportion of solid components. Ultrasound is the simplest, quickest and most cost effective means of demonstrating the hip effusion, the bursa, its contents and extent. Although the compressive effects are well seen sonographically, computed tomography (CT) and magnetic resonance imaging (MRI) provide a better appreciation of the regional anatomy and hip joint disease.     

色素沉着绒毛结节性滑膜炎的MRI表现

目的 探讨色素沉着绒毛结节性滑膜炎(pigmented villonodular synovitis，PVNS)的MRI表现。方法 23例PVNS中膝关节9例，髋关节9例，踝关节3例，肘关节1例，腕关节1例，均经手术和病理证实。23例PVNS均行X线和MR检查，其中4例行CT检查。分析PVNS的影像学表现，着重总结PVNS的MR影像学特点。结果 X线表现：23例均可见关节及软组织肿胀，7例关节内外可出现较致密结节状或分叶状软组织肿块影，19例可见邻近关节骨质侵蚀性小缺损。CT表现：4例中3例可见关节内外结节状或分叶状软组织肿块，增强扫描可见结节样强化，1例CT仅显示关节囊增厚，关节内积液。MRI表现：23例病变部位增生肥厚的滑膜在T1WI上呈中等或中等稍低信号，在T2WI上呈中等稍高信号，其内可见多发散在结节，呈T1WI、T2WI低信号灶；增生肥厚的滑膜在快速梯度回波(FFE)T2WI序列上呈明显结节样低信号。23例病变关节均可见不同程度的关节积液。19例有骨质破坏，表现为凹陷性类圆形骨质缺损，骨缺损区T1、T2WI呈中等信号灶，周围有硬化边，呈T1WI、T2WI低信号。相邻骨髓腔内可见弥漫性反应性水肿灶，呈片状高T2信号。结论 MRI能准确显示PVNS的病变范围和程度，对PVNS有定性诊断价值。