Avascular osteonecrosis of the acetabulum

 Objective. To investigate the possible occurrence of osteonecrosis in the acetabulum in patients with non-traumatic necrosis of the femoral head. Design and patients. One hundred and seventy-nine patients with non-traumatic femoral head necrosis were assessed by MRI and radiography for the presence of acetabular necrosis. Three criteria were established to differentiate between osteonecrosis and osteoarthritic changes: (1) heterogeneous morphology and irregular contours of the lesion; (2) typical demarcation lines of osteonecrosis; (3) deficient accumulation of intravenous gadolinium in the affected regions. Results. In four patients histological confirmation of acetabular necrosis was obtained. The MR analysis of 22 acetabula (9.5% of those examined) showed changes which suggested osteonecrosis. No cystic lesions were demonstrated in the subchondral bone of any patient. Two cases of acetabular necrosis were found without an ipsilateral femoral head necrosis. In two patients of the 14 who had undergone total hip replacement following necrosis of the femoral head, aseptic loosening of the acetabular component was found. Conclusion. The study suggests that acetabular necrosis may be an accompaniment to aseptic necrosis of the femoral head. Further work is required to assess its importance in premature loosening of the acetabular element of total hip arthroplasty.     

人工关节置换治疗晚期股骨头缺血性坏死合并严重股骨颈前倾角畸形

目的 探讨晚期股骨头缺血性坏死合并严重股骨颈前倾角畸形患者采用普通假体髋关节置换的手术方法及临床疗效.方法 本组男9例,女6例;年龄30～42岁,平均37岁.前倾角40°～50°,术前Harris评分(59±8)分,术中通过将股骨假体缩小前倾角20°～30°,同时将髋臼杯前倾角增大10°～15°,使其基本恢复正常对合关系,防止关节前脱位.术后定期影像学检查和临床疗效Harris髋评分.结果 术后15例患者均获得随访2.5～3.7年(平均2.9年),关节假体稳定性良好,关节活动度基本正常.术后2年Harris评分为(88±6)分,与术前相比,疗效显著(P<0.01).结论 晚期股骨头缺血性坏死合并严重股骨颈前倾角畸形患者手术中通过对普通的股骨假体及髋臼杯安放的角度的联合调整,使关节置换术后人工假体与髋臼的对合基本恢复正常,疗效显著,同时避免了使用小柄股骨假体、转子下截骨或使用特殊前倾角股骨假体等治疗方法.     

股骨头骨骺缺血坏死的影像学及生物力学研究

目的：分析股骨头骨骺缺血坏死的影像学及生物力学特点。材料和方法：对46例患者的X线平片、CT及MRI等影像学征象进行观察并对全部病例的双侧髓关节做测量。结果：影像学特点包括骨骺硬化、变扁、碎裂、囊变和关节半脱位、股骨颈变粗及干骺增宽。测量结果为颈干角（CDAngle）、HE角及臼／头（A／F）比值减小，髋关节内侧间隙（CMS）和身体中轴至股骨头中心的距离（BC—FH）增大。结论：在局部血洪障碍及骨与关节内压力显著升高的基础上发生臼头对合不适应及髋关节受力方向偏移为股骨头骨骺缺血坏死的主要生物力学特点。     

Cartilage lesions in the hip: diagnostic effectiveness of MR arthrography

PURPOSE: To evaluate the diagnostic performance of magnetic resonance (MR) arthrography in the detection of articular cartilage lesions in patients suspected of having femoroacetabular impingement and/or labral abnormalities. MATERIALS AND METHODS: Forty-two MR arthrograms obtained in 40 patients with a clinical diagnosis of femoroacetabular impingement and/or labral defect were retrospectively analyzed. Two readers independently interpreted the images for cartilage lesion location, depiction, and characteristics. Within 6 months after MR arthrography, each patient underwent open hip surgery, during which the entire cartilage of the hip joint was inspected. Sensitivity, specificity, accuracy, and positive and negative predictive values were calculated. kappa values were calculated to quantify the level of interobserver agreement. RESULTS: At surgery, most (37 [88%] of 42) cartilage defects were identified in the anterosuperior part of the acetabulum. In 23 (55%), 12 (29%), 10 (24%), and 10 (24%) hips, lesions were found in the posterosuperior acetabulum, anteroinferior acetabulum, posteroinferior acetabulum, and femoral head, respectively. The sensitivities and specificities of MR arthrographic detection of cartilage damage in all regions combined were 79% (73 of 92 regions) and 77% (91 of 118 regions), respectively, for reader 1 and 50% (46 of 92 regions) and 84% (99 of 118 regions), respectively, for reader 2. At interobserver comparison, agreement was fair (kappa = 0.31) for detection of cartilage lesions in the femoral head and poor (kappa 相似文献   

暂时性骨质疏松的MRI表现

目的 分析暂时性骨质疏松的MR表现。方法 回顾性复习8例暂时性骨质疏松的MR表现。8例均行常规MR轴面和冠状面T1、T2WI。8例中男5例，女3例，年龄范围12-70岁。3例女性患病时均不在妊娠期。结果 双侧髋部病变7例，左肩部病变1例。于T1WI呈低信号8例；T2WI呈正常信号2例，中-高信号3例，高信号3例。这种骨髓水肿征象涉及髋臼1例、股骨头5例，T2WI示双侧髋关节少量关节渗液。结论 MRI有利于明确暂时性骨质疏松的诊断、病变部位和范围。     

Bilateral idiopathic chondrolysis of the hip: a case report

A case of bilateral idiopathic chondrolysis of the hip is presented. Chondrolysis is a process characterized by progressive necrosis of the hyaline cartilage of the acetabulum and femoral head, resulting in secondary joint space narrowing and stiffness. A 14-year-old boy was followed during a 2-year period, and the diagnostic values of the different imaging methods (radiography, magnetic resonance imaging [MRI], and bone scintigraphy) were evaluated. Scintigraphic evidence of marked periarticular uptake and premature fusion of the epiphysis of the greater trochanter was a reliable indicator of chondrolysis. Furthermore, the bone scan could precede other imaging methods (radiography and MRI) in the diagnosis of the progression of the pathologic process, status of the remodeling activity, and early involvement of an opposite joint. Given the high sensitivity of bone scans and the high specificity of radiographic and MRI examinations in the diagnosis of acute chondrolysis of the hip, all three methods are valuable and should be used as complementary diagnostic tools.     

MR imaging findings in transient osteoporosis of the hip

Purpose: The authors sought to describe the magnetic resonance (MR) imaging findings including perfusion imaging, in association with the course of acute bone marrow oedema syndrome (aBMEs), in a group of patients with acute hip pain and a final diagnosis of transient osteoporosis of the hip (TOH). Materials and methods: From 217 patients referred with a probable diagnosis of avascular necrosis (AVN) of the femoral head, we identified 42 patients who had clinical and radiographic findings not relevant to AVN. MR imaging examinations were performed on a 1.0T scanner. Perfusion imaging was performed in 20 patients. The bone marrow oedema (BME) was classified in four stages. In addition, the presence or absence of oedema in the subchondral area and the presence of other subchondral lesions were recorded. Acetabular bone marrow was also assessed for the presence of oedema. The quantitative measurements included: maximum size of the effusion, percentage of enhancement (PE) and time of peak enhancement of abnormal marrow compared to the first pass, on the perfusion images. Results: Osteopenia was present on plain radiographs in 87% of cases. The most common pattern of BME was extending to the femoral head and neck. Acetabulum was involved in 16.6%. In 22.6% the BME spared the subchondral region of the femoral head. There were two cases (4.7%) with subchondral changes. A joint effusion was noted in 33 of the 42 patients. On perfusion imaging, a delayed peak enhancement was noted in 20 patients between 40 and 65 s after the first pass of contrast. No patient had any evidence of femoral head collapse or change in sphericity on follow-up MRI. None of the patients developed avascular necrosis in a time frame of 18 months from the onset of the acute hip pain. Conclusion: The aBMEs MR imaging pattern varies and is most commonly appearing on X-rays as osteopenia. Absence of subcondral lesions, delayed peak enhancement of the abnormal marrow on perfusion images, and sparing of subchondral zone from marrow oedema are MR imaging findings highly correlated to TOH.     

Segmental patterns of avascular necrosis of the femoral heads: early detection with MR imaging

Thirty-two patients (64 hips) in whom avascular necrosis (AVN) of the femoral heads was highly suspected clinically were studied by magnetic resonance (MR) imaging, radionuclide bone scintigraphy, and conventional radiography. MR studies were positive for AVN in 37 hips, compared with 30 positive scintigraphic studies. In all cases in which scintigraphy and radiography were positive, MR imaging demonstrated decreased signal from the affected femoral heads, indicative of bone marrow disease. Imaging results were confirmed by biopsy or subsequent imaging appearances. In patients with negative initial scintigraphic and radiographic studies, the MR imaging criterion for a positive study was a moderately decreased bone marrow signal displaying segmental patterns within an otherwise normal-appearing femoral head on relatively T1-weighted images. In this series of high-risk patients, radionuclide scintigraphy had a sensitivity of 81%, compared with 100% for MR imaging. MR imaging should be the imaging modality of choice for early evaluation of bone marrow changes indicative of AVN.     

Hip arthropathy in a patient with primary hemochromatosis: MR imaging findings with pathologic correlation

Arthropathy is a major clinical manifestation in primary hemochromatosis, typically affecting the metacarpophalangeal joints. Hip arthropathy is not uncommon, with radiologic features resembling osteoarthritis or calcium pyrophosphate dihydrate (CPPD) crystal deposition disease. We describe the MR imaging findings of the hip in a patient with severe hip arthropathy and primary hemochromatosis and correlate them with the histopathologic findings. MR imaging showed severe degenerative changes, with large subchondral cysts and subchondral sclerosis in the femoral head and acetabulum. There was conspicuous correlation between MR imaging and pathologic findings of the resected femoral head. However, MR imaging failed to reveal intra-articular iron.     

Bildgebung bei Hüftgelenkendoprothesen

The hip joint is the largest joint in the human body and consequently, its evaluation by diagnostic imaging is highly important. This includes imaging of hip joint arthroplasty, which is used to avoid joint immobility following a wide spectrum of diseases, such as end-stage degenerative disease, avascular necrosis of the femoral head or post-traumatic fractures. Conventional radiography is still the standard imaging modality for the evaluation of hip arthroplasty both directly following surgery and for periodical follow-up. In the majority of cases conventional radiography enables adequate assessment of early and late complications that can arise following hip arthroplasty, such as loosening, prosthetic or periprosthetic fracture, luxation, infection and soft tissue calcification. If the diagnosis cannot be established by means of radiography, advanced imaging methods such as computed tomography (CT) and magnetic resonance imaging (MRI), with or without injection of contrast media, may provide additional information. This is particularly true for the depiction of inflammatory processes. Regardless of the imaging modality used patients’ clinical symptoms must also be taken into account in order to establish the correct diagnosis.     

成人髋臼发育不良并发骨囊变的影像学研讨

目的探讨成人髋臼发育不良（acetabulardysplasia,AD）并发骨囊变的临床及影像学表现特点,提高其影像诊断能力。方法回顾性分析66例成人AD的标准双髋关节前后位X线片、28例CT片、10例MRI片的影像学资料,并按有无髋周骨囊变进行分组：囊变组、无囊变组。测量方法有：髋臼指数、Sharp角、CE角、髋臼顶切线角、AHI（股骨头覆盖率）、髋关节内间隙、髋关节上间隙。数据均以平均值±标准差（x±s）方式表示,通过了检验进行统计学处理,以P〈O．05为具有显著性检验。结果66例成人AD中出现并发症的61例,占92．4％,其中髋关节脱位（含半脱位和脱位）49例,占74．2％,继发骨性关节炎18例,占27．3％。髋臼及股骨头囊状改变24例,占36．4％,其中单纯髋臼囊变14例,占21．2％,股骨头和髋臼同时囊变5例,占7．5％,单纯股骨头囊变5例,占7．5％．襞变组和无囊变组对照测量结果显示两组数据除髋臼指数和髋关节内间隙无差异外（P〉O．05）,其余均有显著性差异（P〈O．05）。结论成人髋臼发育不良易并发髋周骨囊变（软骨下假囊肿）,其发病率与年龄呈正相关,X线、CT、MRI检查是诊断成人AD并发髋周骨囊变（软骨下假囊肿）的有效检查手段,MRI在显示成人AD并发髋关节周围骨囊变方面优于x线平片和CT,尤其是早期显示软骨下小囊变。     

Legg-Calvé-Perthes disease: MR imaging evaluation during manual positioning of the hip--comparison with conventional arthrography.

PURPOSE: To evaluate the use of magnetic resonance (MR) imaging during manual positioning of the hip, or multipositional MR imaging, in an open-magnet configuration to study femoral head containment, articular congruency, and femoral head deformity in Legg-Calvé-Perthes disease. MATERIALS AND METHODS: In 12 children with advanced Legg-Calvé-Perthes disease, multipositional MR imaging and conventional arthrography were compared in the assessment of containment, femoroacetabular congruency, and femoral head deformity. Images of the hips in several positions were compared subjectively and objectively. RESULTS: MR imging correlated well with arthrography for overall subjective assessment of severity of disease (r = 0.71, P = .01), with good interobserver agreement (kappa = 0.65, P < .001). MR images demonstrated all cases of hinge abduction shown arthrographically. However, MR imaging failed to depict one case of femoral head flattening. MR imaging correlated well with arthrography in the objective evaluation of joint fluid and lateral subluxation (r = 0.80, P < .01). MR imaging correlated poorly with arthrography in the measurement of sphericity of the femoral head. CONCLUSION: Multipositional MR imaging with an open-magnet configuration was comparable to arthrography for demonstration of femoral head containment and congruency of the articular surfaces of the hip. In the evaluation of deformity, it performed less well.     

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     

Hip Chondrolysis and Femoral Head Osteonecrosis: A Complication of Periacetabular Cryoablation

PurposeTo describe a new complication and retrospectively identify the incidence and risk factors for hip chondrolysis and femoral head osteonecrosis associated with percutaneous cryoablation of periacetabular malignancies.Materials and MethodsIn this retrospective study, 45 patients with a total of 113 musculoskeletal lesions were treated by percutaneous image-guided cryoablation between May 2008 and June 2013. Included in the treated population were 10 patients with a total of 12 periacetabular lesions. Clinical and imaging follow-up of at least 2 months was reviewed for evidence of femoral head osteonecrosis or hip chondrolysis. Parametric and nonparametric statistical methods were used to assess patient demographics and treatment technique and parameters on the development of hip chondrolysis/femoral head osteonecrosis.ResultsHip chondrolysis/femoral head osteonecrosis developed in 40% of patients (four of 10) and in 33% of treated periacetabular lesions (four of 12). All patients in whom chondrolysis/osteonecrosis developed were women. Needle proximity to the acetabulum (< 5 mm) was a significant predictor of chondrolysis/osteonecrosis development (P = .01). Three of the four patients in whom chondrolysis/osteonecrosis developed have undergone total joint replacement.ConclusionsPeriacetabular cryoablation can result in transarticular extension of the ablation zone, which may result in the development of hip chondrolysis and femoral head osteonecrosis. The proximity of the cryoablation probe to the acetabulum is a significant risk factor in the development of this complication.     

股骨头坏死CT与MRI诊断的临床分析

目的:观察股骨头坏死CT与MRI征象,探讨其临床诊断价值。方法:回顾性分析我院2008年3月～2009年1月经临床病例证实的36例60个股骨头坏死的CT和MRI影像学资料,分析其诊断方法及临床价值。结果:Ⅰ～Ⅱ期共30个股骨头,CT检查16髋未见明显异常征象,14髋发现条带状和斑片状高密度硬化及局部囊变等征象。MRI检查均表现为不等的片状或线状高信号,并伴有少量关节腔内积液。Ⅲ期:17个股骨头,CT发现有16髋骨小梁缺失以及细小囊性变形成,而MRI发现17髋,表现为骨小梁缺失,部分呈长T1、T2信号。股骨头塌陷13例,CT发现12例,MRI发现13例。结论:MRI检查股骨头坏死,能提供其不同时期的影像特征,并可做出准确的判断,是临床检查股骨头坏死的一种较佳方法。     

Screening for avascular necrosis of the hip with rapid MRI: preliminary experience

PURPOSE: The purpose of this work was to compare rapidly acquired MR images with routinely employed SE and turbo SE (TSE) images in screening for hip avascular necrosis (AVN). METHOD: Twelve patients with findings suspicious for radiographically occult AVN of one or both hips were studied with our routine screening protocol (imaging time >7 min) and similarly weighted, rapidly acquired MR sequences (imaging time <1 min). RESULTS: The rapidly acquired MR images were judged to be similar to the routine protocol in demonstrating marrow edema, irregular lines within the femoral head characteristic of AVN, and osteoarthritis. CONCLUSION: The rapidly acquired MR sequences that we studied reliably revealed the presence or absence of AVN, marrow edema, and osteoarthritis of the hip in our sample population when compared with SE and TSE sequences that we routinely perform. Further investigation of rapidly acquired MR sequences is warranted, as imaging time may be dramatically reduced and patient throughput increased.     

骨髓内减压与加压注药在成人 股骨头坏死中的应用

目的观察骨髓内减压与动脉脉冲加压注药对成人股骨头缺血坏死疗效的影响。方法应用ZC-Ⅰ型椎间盘切割器骨钻对82例成人股骨头缺血坏死,进行骨减压,并介入靶血管脉冲式五联药物灌注,进行联合治疗。结果通过12～48个月的随访观察,关节疼痛缓解率,关节活动改善率,头颈区新生血管、新生骨改变均有显著变化。结论该治疗方法安全可靠,疗效优于单纯介入药物灌注。     

髋关节改良侧位摄影的实际应用

目的 设计一种既操作简便又与常规髋关节侧位同样拍摄效果的新体位.方法 采用不同摄影角度对骨骼模型进行X线摄影,测量股骨头、颈充分显示时中心线倾斜角度和骨骼模型倾斜角度,并对头、颈显示情况评分;对30例髋关节X线摄影患者加照新侧位,并与常规侧位的实际可操作性和图像质量进行对比.结果 模拟摄影得出中心线向头侧倾斜35°~45°,身体冠状面与探测器角度60°~70°,评分为3分;新侧位具有可行性,对关节面、间隙显示率均为96.7%,股骨头、颈均为100%,大粗隆为80%,小粗隆为100%.结论 改良髋关节侧位摄影方法同样可以显示股骨头、颈和其余诸组成骨情况.     

成人髋臼结构不良CT应用价值

目的　探讨CT对成人髋臼结构不良的诊断价值。方法　对 2 8例髋臼结构不良患者的 5 6个髋关节CT资料进行回顾性分析。结果　成人髋臼结构不良的CT影像中 ,75 .0 %髋臼表现有前部发育不良 ,而髋臼前后部均发育不良 ( 14 .4% )和臼窝形态异常 ( 14 .9% )者少见 ,5 7.1%髋臼顶部有发育不良。此外 ,CT发现继发性骨关节病和股骨头缺血坏死分别为 91.1%和 16 .1% ,均高于平片所见。结论　CT有助于全面了解髋臼发育状况及其与股骨头相互适应情况 ;确定髋臼结构不良的基本类型 ;早期发现继发性骨关节病和股骨头缺血坏死及评估髋关节病变的严重程度。     

Low field magnetic resonance imaging of femoral neck fractures

Fourteen patients with cervical hip fractures were treated with internal fixation using titanium screws. The femoral head vitality was evaluated with 99Tcm-MDP scintigraphy and scintimetry within 2 weeks postoperatively and by serial low field magnetic resonance imaging (MR). Two patients with reduced radionuclide uptake (femoral head ratio less than 1.0) developed radiographic signs of femoral head necrosis. MR disclosed the definite area of the necrosis at 2 and 12 months after fracture, respectively. In three of the patients with a high scintimetric uptake (femoral head ratio greater than or equal to 1.0), MR revealed a focal decrease of the signal intensity in the femoral head or neck at 2, 3 and 7 months after fracture, respectively. The radiographs in one of these patients were normal at 7 months after fracture. The second one showed signs of necrosis at 16 months and the last one developed delayed/non-union. With a non-ferromagnetic osteosynthesis the healing course after femoral neck fracture can be studied with low field MR equipment without disturbing artifacts. The time period between ischaemia and definite abnormalities on MR may embrace several months.