The "hot patella" sign: is it of any clinical significance? Concise communication

The presence of the "hot patella" sign was evaluated in a prospective study of 200 consecutive bone scans, and in a review of scans from 148 patients with various metabolic bone disorders and 61 patients with lung carcinoma. The incidence was found to be 31%, 26% and 31% respectively. This sign is an extremely common scan finding and may be seen in association with a wide variety of disorders. It is concluded that this sign cannot be considered to be of diagnostic value.     

What is the role of bone scintigraphy in the diagnosis of infected joint prostheses?

AIM: To analyse the role played by bone scintigraphy in the diagnosis of infected joint prostheses. METHODS: The study included 77 patients, aged 32-77 years, in whom infection of a joint prosthesis (48 hip, 29 knee) was suspected. In all patients the following examinations were performed consecutively: a two-phase Tc methylene diphosphonate (Tc-MDP) bone scan, a Tc hexamethylproplyene amine oxime (Tc-HMPAO) labelled white blood cell (WBC) scan, and a Tc microcolloid bone marrow (BM) scan. The minimum interval between examinations was 48 h. The diagnoses were based on data obtained from bacteriological cultures. RESULTS: The bone scan was positive in all patients and 28 of them had an infection (sensitivity 100%, specificity 0%). The WBC scan was positive in 61 patients but only 27 had an infection. The WBC scan was negative in 16 patients, and the possibility of infection was discarded in 15 of these cases (sensitivity 96%, specificity 30%). The results of the bone marrow scan were not compatible with those of the WBC scan (suggestive of infection) in 27 patients: 26 of them had prosthesis infection. The results of both examinations were compatible in the other 34 patients and the possibility of infection was discarded in 33 of these patients (sensitivity 92.8%, specificity 98%). The addition of a BM scan to a WBC scan decreased the sensitivity from 96% to 92.8% but increased specificity from 30% to 98%. The addition of a bone scan to this dual combination did not alter the results. CONCLUSIONS: When infection of a prosthesis is suspected the diagnostic procedure should start with a WBC scan followed, if positive, by a BM scan. This procedure reduces the cost, the time required for a diagnosis, and the dose of radiation received by the patient.     

Stress fractures of the femoral neck: A scintigraphic sign for early diagnosis

Two patients with hip pain are presented; both patients were on steroid therapy. The diagnosis of a stress fracture was initially missed because the patients were not exceedingly active and the plain roentgenograms were essentially normal. The bone scan demonstrated a discretely localized area of increased radionuclide uptake in the femoral neck, which alerted us to the correct diagnosis. This scintigraphic sign is helpful in arriving at an early diagnosis and preventing prolonged disability.     

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.     

99mTc-labelled antigranulocyte anibody fragment Fab scintigraphy (sulesomab,leukoscan) and three-phase bone scintigraphy in the study of painful hip and knee prosthesis

We aim to assess the diagnostic utility of the combination of a three phase bone scintigraphy (3FBS) and scintigraphy with Fab'antigranulocyte fragments-99mTc (Sulesomab, Leukoscan) in patients with painful joint replacements. We studied 29 patients (22 women and 7 men with mean age 64 years) with knee (15) and hip (14) prosthesis. Scintigraphy was performed with a Siemens Orbiter 75 gammacamera with all purpose collimator. 3FBS was performed as usual with 740 MBq of MDP-99mTc. Sulesomab images were obtained at 1 and 4 hours following injection of 740 MBq, with 300,000 cts per view (knee) and 500,000 cts per view (hip). Both scintigraphic studies were interpreted visually by two nuclear medicine physicians with a 0, 1, 2, 3 score corresponding to normal or mild, moderate or intense hyperactivity respectively. Interpretation criteria for bone infection was Sulesomab uptake grade 2 or 3 in a moderate or large sized area, with congruent hyperactivity on the bone scan. Grade 1 uptake with Sulesomab was considered nonspecific associated to nonseptic conditions. The frequent pattern of uptake in synovial femoral tissue (cap shape sign) in knee prosthesis was considered nonspecific. Diagnostic confirmation procedures were surgery and culture (9) and follow-up (20). All six septic joints were correctly identified. A false positive result was obtained in a case of mechanical loosening in the knee. Negative studies were very helpful in the exclusion of infection. Our conclusion is that sensitivity is high, 100%, and that a normal or grade 1 Sulesomab image makes the presence of infection improbable.     

螺旋CT三维重建对外伤性髋关节骨折的诊断和术前评估价值

目的 评估螺旋CT三维重建(3D-CT)在外伤性髋关节骨折的诊断价值及治疗对策.方法 回顾性分析26例外伤性髋关节损伤的X线片和螺旋CT三维重建等临床资料.结果 26例外伤性髋关节骨折中,11例复合型骨折经3D-CT检查证实X线片检查漏诊4例;合并股骨头脱位及骨折5例中3D-CT 发现X线片漏诊股骨头骨折2例.结论 3D-CT在外伤性髋关节损伤的诊断中,与普通的X线片和CT扫描相比,显示了其明显的优越性.     

Recovery of femoral head perfusion after drainage of septic joint

A 64-year-old woman was febrile and had pain near the right hip. Blood cultures grew beta hemolytic streptococci. A bone scan showed reduced activity in the right femoral head and neck compared with the left femoral head and neck. She was treated with intravenous antibiotics and surgical decompression of a tense and bulging right hip joint. Five days later, a repeat bone scan revealed much of the femoral head activity to have returned. By day 20 after the initial bone image, there was intense activity throughout the femoral head and neck. Prompt relief of a distended hip joint can result in reperfusion of the femoral head and neck.     

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.     

异体骨移植在全髋关节置换术后感染股骨翻修中的应用

目的 探讨异体骨植骨治疗髋关节置换术后感染股骨骨质缺损的有效性与可行性.方法 髋关节置换术后感染股骨侧骨质缺损患者20例,在二期翻修时采用异体植骨,其中16例股骨侧使用骨水泥固定假体结合打压植骨,4例股骨侧使用非骨水泥固定假体结合异体皮质骨支撑植骨.术后定期随访,根据X线片及Harris评分结果进行评价.结果 所有患者均获随访,平均随访时间20.3个月(4～61个月),X线片上无明显异体骨溶解征象,Harris评分从术前的平均34.2分提高到最后随访时的平均87.7分,患者满意率为90%,在最后随访时没有感染复发患者.结论 异体骨植骨治疗髋关节置换术后感染后股骨侧骨质缺损是有效且可行的.     

Rapidly destructive coxarthrosis: case study and literature review

Rapidly destructive coxarthrosis is a rather rare disease that affects most frequently women between 60 and 66 years. This bone disease is defined by a rapid chondrolysis with total obliteration of the joint space in the superolateral segment of the joint in an average period of one year, followed by rapid bone destruction of the femoral head and the roof of the acetabulum. This periarticular osteolysis causes a rising of the femoral head. The radiographic appearance shows minimal osteophytosis but this is never absent. The study of follow-up radiographs is helpful to make a choice in the differential diagnosis among the ethiologies of a rapidly destructive hip.     

The value of the bone scan in idiopathic regional migratory osteoporosis

Idiopathic regional migratory osteoporosis is a self-limited entity of unknown origin, which has received little attention in the nuclear medicine literature. It is characterized by severe joint pain, typically in a hip, with normal laboratory and normal early radiographic findings. Spontaneous recovery occurs, but recurrence is frequent in another joint, often the opposite hip. Recurrence in the same joint has never been reported. The bone scan is shown to be positive with first symptoms and is important in the diagnosis and management of this entity. Three cases are presented.     

改良髋关节磁共振成像扫描方法在发现骶髂关节病变中的应用价值

目的：通过对髋关节磁共振成像（MRI）冠状位扫描的改良,从而发现骶髂关节病变,弥补临床医生判断失误,提高疾病的检出率。方法对265例申请髋关节MRI检查的患者增加冠状位扫描层数,使每例患者双侧骶髂关节均能大部分显示。结果发现骶髂关节病变的共计20例,发现率为7．5％,年龄11-65岁,其中强直性脊柱炎16例,退行性骨关节炎2例,骶髂关节结核1例,外伤导致骨挫伤1例。结论骶髂关节病变,尤其是强直性脊柱炎是一种以危害年轻人为主的慢性炎性疾病,起病隐匿,临床部分患者以髋关节为主述症状,引起误诊,MRI在检查髋关节时适当在冠状位上增加扫描层数,能发现7．5％的遗漏病变,方法简便易行,值得推广。     

Long-term functional recovery in patients with custom-made 3D-printed anatomical pelvic prostheses following bone tumor excision

BackgroundAnatomical custom-made prostheses make it possible to reconstruct complicated bone defects following excision of bone tumors, thanks to 3D-printed technology. To date, clinical measures have been used to report clinical-functional outcome and provide evidence for the effectiveness of this new surgical approach. However, there are no studies that quantified the achievable recovery during common activities by using instrumental clinical-functional evaluation in these patients.Research questionWhat is the motor performance, functional outcome and quality of life in patients with custom-made 3D-printed pelvic prostheses following bone tumor?MethodsTo analyze motor performance, six patients performed motion analysis during five motor activities at follow-up of 32 ± 18 months. Joint angles, ground reaction forces and joint moments of the operated and contralateral limbs were compared. On-off activity of lower-limb muscles were calculated from electromyography and compared to a healthy matched population. To analyze functional outcome and quality of life, differences in measured hip abductor strength between limbs were evaluated, as well as clinical-functional scores (Harris Hip Score, Barthel Index, Musculoskeletal Tumor Society score), and quality of life (SF-36 health survey).ResultsWe found only slight differences in joint kinematics when comparing operated and contralateral limb. The activity of gluteal muscles was normal, while hamstrings showed out-of-phase activities. Ground reaction forces and hip moments showed asymmetries between limbs, particularly in more demanding motor activities. We found a mean difference in hip abductor strength of 48 ± 82 N between limbs, good clinical-functional scores, and quality of life scores within normative.SignificanceOur study showed optimal long-term results in functional recovery, mainly achieved through recovery of the gluteal function, although minor impairments were found, which may be considered for future improvement of this innovative surgery. The effect of a more loaded contralateral limb on internal loads and long-term performance of the implant remains unknown and deserves further investigation.     

Arthroscopic treatment of the hip in early and midstage degenerative joint disease

The purpose of this study was to present the technique of arthroscopic capsule release in patients with early and midstage degenerative joint disease of the hip. In 22 patients we performed an arthroscopic capsular release of the hip joint capsule with simultaneous synovectomy and percutaneous drilling of areas of bone edema. The age of the patient ranged from 28 to 65 years (mean 52 years). There were 14 male and 8 female patients. All patients had suffered from a significant reduction of quality of life. In 15 of the 22 patients hip arthroplasty was already indicated in another institution. The preoperative Harris hip Score of 12 patients was below 69 points, 8 patients had a score between 70 and 79 points and 2 patients had a score between 80 and 89 points. At the time of follow-up (mean 26 months after surgery) 1 patient scored below 69 points, 3 patients scored between 70 and 79 points in the Harris hip score. Two patients scored between 80 and 89 points and 16 patients reached a score between 90 and 100 points. Subjective and objective 18 of 22 patients showed clinical relevant improvement. There was no complication in this series. Four patients underwent hip arthroplasty between 6 months and 2 years after the arthroscopic procedure. Minimal invasive arthroscopic treatments seem to decrease the subjective and objective complaints in early and midstage degenerative arthritis of the hip.     

Predictors of a positive baseline bone scan in breast cancer

The aim of this retrospective study was to determine the predictors of a positive bone scan in female patients with breast carcinoma. The participants were 126 females with newly diagnosed breast carcinoma and a baseline bone scan. Patients who had started treatment before their bone scan were excluded. Bone scans were assessed as "no metastases" or "definite skeletal metastases" without knowledge of the patient's predictor variables. Those with "possible metastases" were correlated with other available imaging and clinical information, and recategorized as "no metastases" or "definite skeletal metastases". Results were compared with predictor variables. Significant predictors were increasing age, a higher histopathological grading and positive progesterone receptor status following a forward-stepwise logistic regression analysis. Axillary nodal status, tumour size and oestrogen receptor status did not correlate with a positive bone scan. Not every patient needs a staging bone scan. This study is important because it predicts the need for baseline scintigraphy for specific patients in whom skeletal metastases are more likely to be present or to develop. The findings are particularly valuable in times of worldwide resource scarcity and evolving surgical practice.     

The pitfalls of planar three-phase bone scintigraphy in nontraumatic hip avascular osteonecrosis.

PURPOSE: This study documented the previously reported lower sensitivity of routine planar three-phase bone scintigraphy (BS) performed using a high-resolution parallel-hole collimator compared with MRI to diagnose nontraumatic avascular necrosis of the hip (AVN). METHODS: Six observers reviewed 143 bone scintigrams obtained in patients with nontraumatic hip pain (n = 120) or a control group (n = 23). All patients had a standard radiograph and MRI within 2 months of the BS. Of 280 hips, 148 (53%) were painful on the day of the examination. The osteonecrosis group (AVN) consisted of 93 instances of AVN in 58 patients. Although it departs from the clinical situation, this method evaluated the intrinsic performance of the imaging method. The data were analyzed using a receiver operating characteristic method. RESULTS: For the six observers, the A(z) values were 0.65, 0.67, 0.66, 0.67, 0.73, and 0.79, respectively, and 0.66, 0.71, 0.75, 0.81, 0.81, 0.82, and 0.84 after removing hip diseases other than AVN through data manipulation. Bone marrow edema, as seen on MRI, was the most frequently reported misleading sign in false-positive diagnoses, especially in the early or late phases of the disease. False-negative diagnoses misclassified the scans as "asymptomatic hips" in 28 of 30 cases. Twenty-two of 30 scans appeared normal, but these AVN lesions were small (<25%) and were discovered by chance on MRIs that displayed bilateral involvement associated with radiographic evidence (stage 0 or 1). Thirteen of 20 patients were followed for 3 or more years, and only one worsened. CONCLUSIONS: BS is not indicated to diagnose possible contralateral AVN if the hip is asymptomatic. This study emphasizes the results from the literature; if indicated, a radionuclide hip investigation requires the use of a pin-hole collimator, a SPECT study with scatter correction and iterative reconstruction algorithms, or both.     

Magnetic resonance imaging of occult fractures of the proximal femur

The evaluation of the painful hip in the elderly osteoporotic patient with normal plain radiographs can be difficult. We studied 15 osteopenic patients with normal plain radiographs and suspected hip fractures with magnetic resonance (MR) imaging and found MR to be an excellent aid in detecting occult fractures. A clear fracture was seen in 10 of the 15 patients, who then underwent surgical repair based on the MR study. The remaining patients had no MR-demonstrable fracture and were successfully treated nonoperatively. Some believe that a negative bone scan in this population of patients should be repeated within 3 days prior to a definitive no fracture decision being made. Unfortunately, bone scanning lacks spatial resolution, and increased osteoblastic activity may be caused by other pathologic processes besides fracture. Two of the 15 patients had MR-demonstrated bone infarcts near the fracture. One patient also had femoral head osteonecrosis on the side of the fracture. One patient with metastatic prostatic carcinoma had a hip fracture and one patient with metastatic breast carcinoma had no fracture. Not only is MR imaging an excellent technique for delineating occult fractures, but due to its spatial resolution, associated bone disorders adjacent to fractures can be detected in most instances. From a cost perspective, rapid diagnosis and early treatment of an occult femoral fracture is advisable. A reduced hospital stay pending diagnosis and the early institution of definitive therapy also decrease the chance that a simple non-displaced fracture will displace and require more complex management with resultant increased morbidity and cost. We propose that, especially in elderly, osteopenic patients with normal plain radiographs and a high index of suspicion for hip fracture, MR can serve as the sole additional imaging study in most instances.Presented at the Annual Meeting of the American Roentgen Ray Society, San Francisco, April 1993     

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.     

Comparison of phosphatase isoenzymes PAP and PSA with bone scan in patients with prostate carcinoma.

The aim of this study was to assess the diagnostic value of five biological markers--prostate acid phosphatase (PAP), prostate specific antigen (PSA), tartrate resistant (Tr-ACP), and tartrate labile (TI-ACP) acid phosphatases, and alkaline phosphatase bone isoenzyme (B-ALP)--for the detection of bone metastases in patients with prostate carcinoma. Using the Tc-99m HMDP bone scans of 80 patients scored from 0 (normal) to 2 (diffuse bone involvement) as the "gold standard," a receiver operating characteristic (ROC) analysis was performed. This method allows the determination of different threshold values (corresponding to different couples of sensitivity and specificity) for the assays. An ROC curve comparison was also performed. Results show that B-ALP is the best test for such detection (area under the ROC curve = 0.93; Spearman Rank correlation with bone scan r' = 0.81). Among the other markers, PSA was found to be the best (area under the ROC curve = 0.81; Spearman Rank correlation with bone scan r' = 0.58). In addition to the prostatic tumor markers (PSA and PAP), we suggest the use of the low-cost B-ALP assay in the follow-up of prostate carcinoma patients to determine the optimum moment to perform a bone scan. A normal result of this assay indicates a very low probability of bone metastasis; conversely, raising of B-ALP concentration must lead to a bone scan.     

原发性骨淋巴瘤的MRI常见和特征表现

目的探讨原发性骨淋巴瘤(primary bone lymphoma,PLB)的MRI特征,以提高对该病的诊断和鉴别诊断能力。资料与方法 15例经病理证实的PLB均行MRI平扫及增强扫描。镶边征定义为增强扫描时病变骨大片均匀低信号,边缘花边样明显强化;骨皮质开窗征定义为骨内病变与骨外软组织肿块通过一较小的窗口样皮质破坏区相连。结果 (1)病灶内出现镶边征13例,占93.33%,骨皮质开窗征11例,占73.33%。(2)病理上,骨皮质开窗征是由于瘤细胞在骨髓腔内浸润或渗透性生长,骨皮质内骨小梁保存,故骨皮质轮廓大部完整,当瘤细胞局灶破坏骨小梁,使骨皮质溶解性改变而呈现开窗征;镶边征可能是由于中心片状坏死呈低信号,周围肉芽增生血供丰富,呈现花边样明显强化。结论 骨皮质开窗征和镶边征在PLB的MRI表现中出现率高,可作为诊断PLB的常见和特征表现。