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.     

Idiopathic Synovial Osteochondromatosis of the Hip: Radiographic and MR Appearances in 15 Patients

Objective

To evaluate the radiographic and MR appearance of idiopathic synovial osteochondromatosis of the hip.

Materials and Methods

Radiographs and MR images of 15 patients with idiopathic synovial osteochondromatosis of the hip were assessed. The former were analysed in terms of the presence of 1) juxta-articular calcified and/ or ossified bodies, 2) osteophytes, 3) bone erosion, 4) juxta-articular osteopenia, and 5) joint space narrowing, while for the latter, analysis focused on 1) the configuration of intra-articular bodies, 2) bone erosion, 3) synovial thickening, 4) conglomeration of intra-articular bodies, and 5) extra-articular extension.

Results

At hip radiography, juxta-articular calcified and/ or ossified bodies were seen in 12 of the 15 patients (80%), bone erosion in eight (53%), osteophytes in seven (47%), juxta-articular osteopenia in five (33%) and joint space narrowing in five (33%). In eight patients (53%), MR imaging depicted intra-articular bodies of focal low signal intensity at all pulse sequences, and areas of iso-intensity at T1WI and hyperintensity at T2WI. In three (20%), intra-articular bodies of focal low signal intensity and areas of hyperintensity at all pulse sequences were observed, with areas of iso-intensity at T1WI and hyperintensity at T2WI, while in four (27%), intra-articular bodies of only focal low signal intensity at all pulse sequences were apparent. Synovial thickening was present in 13 patients (87%), bone erosion in 11 (73%), conglomeration of the intra-articular bodies in 11 (73%), and an extra-articular herniation sac in six (40%).

Conclusion

The most common radiographic finding of synovial osteochondromatosis of the hip was the presence of juxta-articular calcified and/ or ossified bodies. MR imaging depicted intra-articular bodies of focal low signal intensity at all pulse sequences, with areas of iso-intensity at T1WI and hyperintensity at T2WI. In addition, the presence of an extra-articular herniation sac was not uncommon.     

Osteoid osteoma of the femoral neck mistaken as a synovial herniation pit

A 36-year-old man presented with 1 year of atraumatic left lateral thigh, groin, and hip pain, and imaging consistent with the diagnosis of femoroacetabular impingement and a labral tear. Imaging concurrently demonstrated a synovial herniation pit. The patient underwent hip arthroscopy, which included femoroplasty, acetabuloplasty, labral debridement, and synovectomy. His pain persisted and further workup confirmed an osteoid osteoma that was mimicking a synovial herniation pit. The osteoid osteoma was treated with radiofrequency ablation. At 18 months follow-up, the patient reported complete resolution of his symptoms. We present the case to highlight distinguishing imaging and clinical findings of these similar-appearing lesions. While neither condition is particularly rare individually, the misidentification of osteoid osteoma as a synovial herniation pit is a unique feature of this case that lead to the patient''s protracted clinical course.     

全涂层表面微孔股骨假体在人工全髋关节翻修术中的应用

目的评价全涂层股骨假体在人工髋关节翻修术后的X线表现和临床效果。方法自1999年1月至2003年12月，对15例患者15髋采用全涂层表面微孔股骨柄假体进行全髋关节翻修术。男6例，女9例；年龄58～82岁，平均66岁。翻修原因：无菌性假体松动10例，感染性松动2例，假体松动、股骨骨折2例，股骨假体位置不良1例。所有患者均采用Harris髋关节评分和手术前、术后定期X线评价。结果15例患者均获随访，随访时问1～5年，平均2．3年。术前平均Harris评分为42分，最后随访时增加至89分。所有患者均在术后3个月后完全负重，原有髋关节疼痛缓解。在最后随访时，有14例股骨柄假体获得骨长入固定，有1例获得稳定的纤维固定。并发症包括股骨干骨折2例，其中1例为股骨柄尖端处无移位骨裂，1例为股骨假体柄远端穿出股骨皮质，术后脱位1例。本组中无假体固定失败的患者。无一例患者发生感染。结论全涂层非骨水泥股骨假体是髋关节翻修股骨侧的良好选择，近期X线和临床效果满意，对个子矮小的患者选用加长翻修柄应慎重。     

Diagnostic imaging of lipoma arborescens

Objective. The imaging characteristics of lipoma arborescens using plain radiographs, computed tomography (CT), and magnetic resonance imaging (MRI) are described. Design and patients. Five patients with a diagnosis of lipoma arborescens are presented. Three had monoarticular involvement of the knee joint. In the remaining two patients both knees and both hips, respectively, were affected. All patients were examined using plain radiographs and MRI. CT was employed in two cases. Results and conclusions. A conclusive diagnosis with exclusion of other synovial pathologies having similar clinical and radiological behaviour can be achieved on the basis of the MRI characteristics of lipoma arborescens. The aetiology of lipoma arborescens remains unknown, but its association with previous pathology of the affected joints in all our patients supports the theory of a non-neoplastic reactive process involving the synovial membrane.     

Synovial chondrosarcoma: report of a case and review of the literature

Primary synovial chondromatosis is a relatively uncommon condition. Synovial chondrosarcoma is considered to be very rare and it is not always clear whether the sarcoma develops by malignant transformation of synovial chondromatosis or whether it arises de novo. Differentiation of the two conditions on clinical and radiographic features is not possible and on histological criteria can be difficult. We report the case of a 59-year-old man who, 4 years after a synovectomy for synovial chondromatosis, developed a synovial chondrosarcoma of the hip. The literature is reviewed.     

Scintigraphic presentation of hip joint synovial chondromatosis

A case of hip joint synovial chondromatosis with an unusual scintigraphic pattern is described. This pattern was suggestive of a hip joint destructive reactive articular process or late manifestations of avascular necrosis of the femoral head. Concurrent radiographs were normal, as were laboratory investigations. Follow-up radiographs six months later showed radiolucencies and erosive bone changes in the diseased joint. Surgical and histopathological findings revealed well developed hip synovial chondromatosis (HSC) with thickened synovium and large, loose, cartilaginous bodies occupying and widening the tightened joint space, with destructive secondary juxta articular pressure and bone erosions. This and other scintigraphic patterns in HSC, and the differential diagnosis of the findings in patients with painful hip presentations are discussed.     

Giant solitary synovial chondromatosis

The purpose of this report is to describe giant solitary synovial chondromatosis, a previously unrecognized feature of synovial chondromatosis that may histologically and radiographically mimic a malignant neoplasm. Giant solitary synovial chondroma is an intra-and/or extraarticular lesion measuring over 1 cm in size and sometimes as large as 20 cm. The radiographic appearance is that of a large, well-marginated mass either of irregular feathery calcification from coalescence of multiple small synovial chondromas, or a rounded calcified mass from the growth of a single synovial chondroma. Radiographically, giant solitary synovial chondromatosis may appear similar to chondrosarcoma and parosteal osteosarcoma.     

Hip osteoarthritis: what the radiologist wants to know

Osteoarthritis (OA) is the most common disease of the hip joint seen in adults. The diagnosis of OA is based on a combination of radiographic findings of joint degeneration and characteristic subjective symptoms. The lack of a radiographic consensus definition has resulted in a variation of the published incidences and prevalence of OA. The chronological sequence of degeneration includes the following plain radiographic findings: joint space narrowing, development of osteophytes, subchondral sclerosis, and cyst formation. There are cases though, that plain radiographs show minor changes and the clinical suspicion of early disease can be confirmed with more sophisticated imaging methods, such as multi-detector computed tomography and MR imaging. The present article will review all the clinical information on the hip OA together with an updated radiological approach, with emphasis on the early depiction and the differential diagnosis of the disease.     

Imaging findings of femoroacetabular impingement syndrome

Femoroacetabular impingement syndrome (FAI) is a pathologic entity which can lead to chronic symptoms of pain, reduced range of motion in flexion and internal rotation, and has been shown to correlate with degenerative arthritis of the hip. History, physical examination, and supportive radiographic findings such as evidence of articular cartilage damage, acetabular labral tearing, and early-onset degenerative changes can help physicians diagnose this entity. Several pathologic changes of the femur and acetabulum are known to predispose patients to develop FAI and recognition of these findings can ultimately lead to therapeutic interventions. The two basic mechanisms of impingement—cam impingement and pincer impingement—are based on the type of anatomic anomaly contributing to the impingement process. These changes can be found on conventional radiography, MR imaging, and CT examinations. However, the radiographic findings of this entity are not widely discussed and recognized by physicians. In this paper, we will introduce these risk factors, the proposed supportive imaging criteria, and the ultimate interventions that can help alleviate patients symptoms.     

Three-dimensional computed tomography analysis of non-osteoarthritic adult acetabular dysplasia

OBJECTIVE: Little data exists on the original morphology of acetabular dysplasia obtained from patients without radiographic advanced osteoarthritic changes. The aim of this study was to investigate the distribution and degree of acetabular dysplasia in a large number of patients showing no advanced degenerative changes using three-dimensional computed tomography (3DCT). MATERIALS AND METHODS: Eighty-four dysplastic hips in 55 consecutive patients were studied. All 84 hips were in pre- or early osteoarthritis without radiographic evidence of joint space narrowing, formation of osteophytes or cysts, or deformity of femoral heads. The mean age at the time of CT scan was 35 years (range 15-64 years). 3D images were reconstructed and analyzed using recent computer imaging software (INTAGE Realia and Volume Player). Deficiency types and degrees of acetabular dysplasia were precisely evaluated using these computer software. RESULTS: The average Harris hip score at CT scans was 82 points. Twenty-two hips (26%) were classified as anterior deficiency, 17 hips (20%) as posterior deficiency, and 45 hips (54%) as lateral deficiency. No significant difference was found in the Harris hip score among these groups. The analysis of various measurements indicated wide variations. There was a significant correlation between the Harris hip score and the acetabular coverage (p < 0.001). CONCLUSION: Our results indicated wide variety of deficiency type and degree of acetabular dysplasia. Hips with greater acetabular coverage tended to have a higher Harris hip score.     

Reliability of the Crowe und Hartofilakidis classifications used in the assessment of the adult dysplastic hip

Objective To assess the inter-observer and intra-observer reliability of two commonly used radiographic classification systems in the evaluation of hip dysplasia in skeletally mature adults. Design Three observers with different levels of training independently classified 62 dysplastic hips on 51 standard anteriorposterior pelvis radiographs according to the criteria defined by Crowe and by Hartofilakidis. To assess intra-observer reliability, the same radiographs were reviewed 3 months later by the same observers. Patients At the time of the radiographic examination, the mean age of the 51 patients had been 54 years (range 18–82 years). Results A high correlation concerning the inter- and intra-observer reliability of both systems was demonstrated. Inter-observer reliability displayed a weighted kappa coefficient of 0.82 for the Crowe and 0.75 for the Hartofilakidis classification. Intra-observer reliability showed a kappa coefficient of 0.86 and 0.79, respectively. Conclusions Both classification systems can be recommended to compare collectives of adult patients with congenital dysplasia of the hip. However, for future clinical practice, it would be advisable to agree on one universally accepted system as a standard in the literature.     

Computed tomography arthrography in traumatic hip dislocation

The newer diagnostic modalities such as computed tomography and magnetic resonance imaging are becoming increasingly used in the evaluation of joint trauma. The combination of computed tomography and arthrography can also be of significant diagnostic value in certain specific situations. In our case report, we describe its use in post-traumatic recurrent hip dislocation and its value, not only in depicting a posterior capsular tear, but also in the diagnosis of an internal joint derangement which may contribute to incongruous reduction of the hip joint.     

Arthrography after total hip arthroplasty: utility of postambulation radiographs

We compare pre-and postambulation arthrograms in 24 patients with total hip arthroplasty. In nearly half (42%) of these cases, the arthrographic evidence of a loosened prosthesis was more obvious after ambulation. Three patients (12.5%) had components which were normal by arthrographic criteria before walking, but were abnormal afterwards. We conclude that postambulation radiographs are valuable in patients who are examined for suspected loosening of prosthetic components.     

Subchondral lucencies and synovial disease: A case report and discussion

The case of a young female with hip pain and acetabular subchondral lucencies on conventional radiographs is presented. Computed tomography (CT) demonstrated subchondral lucencies in the femoral head as well, and an arthrogram revealed synovial irregularities. The differential diagnosis is discussed with an approach to subchondral lucencies. A synovectomy was performed on this patient with pigmented villonodular synovitis.     

Bone marrow edema pattern in advanced hip osteoarthritis: quantitative assessment with magnetic resonance imaging and correlation with clinical examination, radiographic findings, and histopathology

Objective To correlate the amount of bone marrow edema (BME) calculated by magnetic resonance imaging(MRI) with clinical findings, histopathology, and radiographic findings, in patients with advanced hip osteoarthritis(OA). Materials and methods The study was approved by The Institutional Human Subject Protection Committee. Coronal MRI of hips was acquired in 19 patients who underwent hip replacement. A spin echo (SE) sequence with four echoes and separate fast spin echo (FSE) proton density (PD)-weighted SE sequences of fat (F) and water (W) were acquired with water and fat suppression, respectively. T2 and water:fat ratio calculations were made for the outlined regions of interest. The calculated MRI values were correlated with the clinical, radiographic, and histopathologic findings. Results Analyses of variance were done on the MRI data for W/(W + F) and for T2 values (total and focal values) for the symptomatic and contralateral hips. The values were significantly higher in the study group. Statistically significant correlations were found between pain and total W/(W + F), pain and focal T2 values, and the number of microfractures and calculated BME for the focal W/(W + F) in the proximal femora. Statistically significant correlations were found between the radiographic findings and MRI values for total W/(W + F), focal W/(W + F) and focal T2 and among the radiographic findings, pain, and hip movement. On histopathology, only a small amount of BME was seen in eight proximal femora. Conclusion The amount of BME in the OA hip, as measured by MRI, correlates with the severity of pain, radiographic findings, and number of microfractures.     

Bilateral lumbar intraspinal synovial cysts: Gd-enhanced MRI

We report a case of bilateral synovial cysts at L4–L5 level, examined by myelography, computed tomography (CT) and magnetic resonance imaging (MRI). On myelography, the lesions appeared as extradural masses. On CT, the lesions were cystic, with calcifiedd walls and were in close proximity to the facet joints. On MRI, the cystic nature of the lesions was confirmed. The wall appeared hypo-intense both on T1- and T2-weighted images (WI), and enhanced after intravenous administration of Gadolinium-DTPA (Gd-DTPA). This enhancement is thought to represent the peripheral fibrous capsule of the lesion and might be of importance both in the detection and the differential diagnosis of these lesions. Correspondence to: G. Wilms     

Synovial plicae of the knee

This report describes the anatomy, pathophysiology, clinical, and radiographic findings, and treatment of the synovial plicae of the knee joint. The suprapatellar plica is a synovial fold present in the suprapatellar pouch of the knee joint in approximately 20% of the population. This fold may become symptomatic after injury and cause symptoms similar to other common internal derangements of the knee. Double contrast arthrography of the knee can be used to identify the presence of plicae. Although arthrography can identify the presence of a plica, its clinical significance requires close correlation with symptoms and an accurate clinical examination.Presented at the annual meeting of The Association of University Radiologists Tucson, Arizona, March, 1980     

Coexisting secondary intraneural and vascular adventitial ganglion cysts of joint origin: a causal rather than a coincidental relationship supporting an articular theory

Objective To introduce the clinical entity of an intraneural ganglion cyst coexisting with a vascular adventitial cyst arising from the same joint.Design Retrospective review.Patients Two patients presented with predominantly deep peroneal neuropathy due to complex superior tibiofibular joint-related cysts. In addition to having peroneal intraneural ganglion cysts, these patients had vascular adventitial cysts: one involving a capsular arterial branch, the other a capsular vein [as well as a large, recurrent, intramuscular (extraneural) ganglion]. We then reviewed MRIs of 12 other consecutive cases of intraneural ganglia (10 peroneal and 2 tibial) arising from the superior tibiofibular joint that we treated, as well as other reported cases in the literature to determine if there were other (unrecognized) examples supporting the combination of clinical findings and radiographic patterns.Results Retrospective analysis of MRIs in the two surgically proven cases of peroneal intraneural ganglia with vascular adventitial cyst extension showed a common imaging pattern that we have termed “the wishbone sign,” consisting of the connection of the ascending limb of the peroneal intraneural ganglion and the longitudinal limb of the vascular adventitial cyst in the axial plane. Our review suggests that vascular adventitial cyst extension occurs in a large proportion of cases of peroneal intraneural ganglia. A similar growth pattern was noted in a case of a tibial intraneural ganglion.Conclusions The combination of intraneural and vascular adventitial cysts is understandable given our knowledge of normal and pathologic anatomy of para-articular cysts. The combination of intraneural ganglia and vascular adventitial cysts broadens the spectrum of clinical presentations of these cysts and suggests that cysts and their content can dissect from a joint along neurovascular bundles. These cases provide important evidence to support the articular theory for the pathogenesis of not only neural but vascular adventitial cysts as well.     

Fractures of the greater trochanter: intertrochanteric extension shown by MR imaging

Objective. To demonstrate the MR depiction of the intertrochanteric or femoral neck extension of fractures of the greater trochanter, when standard radiographs show only a fracture of the greater trochanter. Design and patients. A retrospective review was performed of the MR and radiographic findings in 13 consecutive patients (10 men, 3 women; ages 24–86 years) with radiographic evidence of fracture of the greater trochanter who were examined with MR imaging. Results. The MR study displayed the fracture of the greater trochanter in all cases. In all but three patients, MR examinations displayed an extension of the fracture into the intertrochanteric region, and in one, also an extension into the femoral neck, although the cortex at this level was not interrupted. Conclusion. When there is radiographic evidence of an isolated fracture of the greater trochanter, MR often shows an intertrochanteric or femoral neck extension of the fracture in both young and older adults. This finding may be a factor in determining the need for surgical intervention. Received: 25 January 2000 Revision requested: 31 March 2000 Revision received: 16 May 2000 Accepted: 22 May 2000