CT evaluation of primary epiphyseal bone abscesses

We reviewed the clinical, radiographic, and computed tomographic (CT) findings in eight children with a histologically proven diagnosis of epiphyseal or apophyseal osteomyelitis. In all cases the femur was involved: in five the osteomyelitis was localized in the femoral condyle, in two it was in the greater trochanter, and in one it was in the femoral head epiphysis. In four of the six cases of epiphyseal involvement there was associated joint effusion or septic arthritis. CT examination may demonstrate a serpentine tract, a sequestrum, cortical destruction or adjacent soft tissue swelling and can differentiate osteomyelitis from other epiphyseal lucent lesions, particularly chondroblastoma and osteoid osteoma. CT yielded important new diagnostic information in seven of the eight patients, failing to do so in only one. In one case, CT showed a wooden splinter in an abscess cavity, which had been mistaken for a sequestrum. When combined with accurate clinical and laboratory information and good quality plain radiographs, CT can lead to an early diagnosis of epiphyseal infection. Early diagnosis helps avoid delays in initiating antibiotic or surgical treatment caused by the unusual (epiphyseal or apophyseal) location of the bone abscess.Presented in part at the Closed Meeting of the International Skeletal Society, San Diego, California, September 1991     

Bone scintigraphy in slipped capital femoral epiphysis

Tc-99m diphosphonate bone scans were performed on 11 children with slipped capital femoral epiphysis. On pinhole hip images, seven hips in seven patients had increased radionuclide uptake in the physis and adjacent proximal femoral metaphysis where the slip had occurred. Three hips in three patients had decreased radionuclide uptake in the femoral head on the side of the slipped epiphysis, indicating compromise of the femoral head blood supply. Three or more months following internal fixation, three children had scintigraphy that showed loss of the usual focal uptake in the physis and adjacent proximal femoral metaphysis. Bone scintigraphy in pediatric patients with slipped capital femoral epiphysis is valuable in defining the metabolic status of the femoral head. Absence of radiopharmaceutical uptake in the affected femoral head indicates that the femoral head is at risk for development of radiographic changes associated with aseptic necrosis.     

Osteomyelitis of the talus: an unusual cause of limping in childhood

Hematogenous osteomyelitis of the talus is a rare and infrequently considered cause of limping in children. We describe five children younger than 2 years of age with osteomyelitis of the talus who had a limp and a paucity of constitutional symptoms. Conventional radiography and scintigraphy were the imaging techniques used. The usual radiologic features include soft-tissue swelling and an osteolytic defect in the talus without sequestrum formation of periosteal reaction. Bone scans were positive in all cases and led to the localization of the lesion in two patients. Definitive diagnosis was made in all cases only after needle aspiration or open biopsy and curettage. Increased awareness of this unusual lesion and its subtle early radiologic manifestations will allow prompt diagnosis and treatment.     

PET/CT of a brodie abscess

Brodie abscess is a rare, localized type of subacute or chronic pyogenic osteomyelitis, usually of staphylococcal origin. Imaging with standard radiographs, bone scintigraphy, and MRI has been described in the literature. We present the case of a 28-year-old patient with pain in the right knee. Whole-body FDG-PET/CT scan showed a solitary FDG-active (SUV max 5.2) intracortical lesion in the meta-/epiphysis of the proximal tibia. CT demonstrated a sclerotic rim around the lesion. A Brodie abscess was considered a possible diagnosis. Multifocality could be excluded. CT-guided transosseous biopsy and curettage was performed and the diagnosis of a Brodie abscess was confirmed.     

婴儿长骨急性血源性骨髓炎的MRI表现及其诊断价值

目的探讨婴儿长骨急性血源性骨髓炎的MRI表现及其诊断价值。资料与方法 21例长骨急性血源性骨髓炎病例均经临床及病理证实,9例采用Siemens Novus 0.35 T MR机,12例采用Siemens Avanto 1.5 T超导型MR机对病灶及邻近关节行轴位、矢状位及冠状位扫描。结果将婴儿长骨急性血源性骨髓炎分为三种类型:(1)骨骺干骺型(16例):病变位于股骨干骺端6例、胫骨干骺端5例、肱骨干骺端5例。16例长骨干骺端病灶合并骨骺及骺板受累、化脓性关节炎,其中2例合并骨膜下脓肿,1例合并骨骺分离,1例合并关节脱位,病灶在T1WI呈低或稍低信号,T2WI、PD-STIR及梯度回波序列呈高信号,以PD-STIR显示更明显;(2)干骺型(3例):病变位于股骨干骺端2例,胫骨干骺端1例,无骺板及骨骺受累,病灶呈片状稍长T1、长T2信号;(3)骨干型(2例):病变位于胫骨及尺桡骨骨干各1例,MRI表现为骨干广泛骨质破坏及骨膜反应。2例增强扫描髓腔内病灶及周围软组织见不均匀斑片状强化。结论婴儿长骨急性血源性骨髓炎有其自身发病特点,认识其病理解剖学基础及MRI表现,对评价骨髓炎的严重程度及预后有十分重要的意义。     

Detection of osteomyelitis at fracture nonunion sites: comparison of two scintigraphic methods

Forty-nine patients with 50 fracture nonunions 4-48 months after injury underwent technetium-99m methylene diphosphonate (99mTc-MDP) scintigraphy on day 1, combined 99mTc-MDP and indium-111 leukocyte (111In-WBC) scintigraphy on day 2, and gallium-67 (67Ga) scintigraphy on day 3. The results were compared to evaluate the relative abilities of these scintigraphic techniques to detect osteomyelitis. Nine patients had clinical evidence of infection at the time of imaging, and 40 patients (41 fractures) did not. Open-biopsy cultures were performed at all fracture sites and were positive at 21 (42%) of the 50 sites. Combined 99mTc-MDP/111In-WBC images were interpreted with the use of two criteria. A positive study by the first criterion required 111In-WBC localization in the region of the nonunion fracture. A positive study by the second criterion required 111In-WBC localization in bone at the fracture site. The first criterion yielded a sensitivity of 84%, specificity of 72%, and accuracy of 74%; the specificity improved to 97% with an accuracy of 88% when the second criterion was used. Ten (25%) of the 40 patients thought not to have osteomyelitis by clinical criteria at the time of imaging had true-positive 99mTc-MDP/111In-WBC studies by biopsy culture results. Gallium-67 studies were interpreted as nondiagnostic if localization of radioisotope at fracture sites was equal to that with 99mTc-MDP, positive if 67Ga localization was greater than that of 99mTc-MDP, and negative if it was less than that of 99mTc-MDP. Twenty-one 67Ga studies were interpreted as nondiagnostic; 11 (52%) of the 21 had culture-positive fracture sites. The accuracy of 67Ga/99mTc-MDP imaging was 39%. Combined 99mTc-MDP/111In-WBC imaging is useful in the detection of osteomyelitis at fracture nonunion sites and improves the specificity of 111In-WBC imaging by differentiating inflammation/infection in adjacent soft tissue from osteomyelitis at the fracture site. Gallium-67 with 99mTc-MDP imaging is not sufficiently reliable in this clinical setting to be useful as an indicator for osteomyelitis.     

Cold defects in in-111 labeled leukocyte imaging of osteomyelitis in the axial skeleton

Use of In-111 oxine labeled leukocytes in the detection of osteomyelitis of the peripheral skeleton usually presents few problems. However, the diagnosis of osteomyelitis is more difficult in marrow-bearing areas because uptake of indium is normal. Sixty-one In-111 labeled leukocyte scans, that had been performed to exclude osteomyelitis of the axial skeleton, pelvis, and proximal long bones, were reviewed. Eight cold defects were identified at sites of suspected osteomyelitis. Five of these were surgically proven osteomyelitis. Nineteen percent of all cases of osteomyelitis in these areas (5 of 26) presented as cold defects. This incidence of osteomyelitis presenting as cold defects is higher than previously reported. Therefore, the possibility of osteomyelitis should be strongly considered when a cold defect is identified in red marrow areas.     

Avulsion fractures of the proximal tibial epiphysis

Fractures of the tibia through the proximal epiphysis are rare. This injury usually results from severe direct or indirect force about the knee, and has not been described as resulting from a patellar tendon avulsion injury. Four patients presented with five avulsion fractures of the proximal tibial epiphysis. All were older adolescent males who had been engaged in jumping sports when the injury occurred; one had bilateral injury. All the patients were treated by closed reduction and plaster cast immobilization for 4-8 weeks, with satisfactory results. On the basis of our cases and five cases previously reported, the authors would agree with Ryu and Debenham's suggestion that the Watson-Jones classification, which divides avulsion fractures of the tibial tubercle into three types, should be expanded to include this fourth type - avulsion fracture of the proximal tibial epiphysis.     

Dysplasia epiphysealis hemimelica of the proximal tibia showing epiphyseal osteochondroma in an adult.

A 33-year-old woman was referred to our hospital complaining of pain and a tumorous lesion in her left knee joint in the absence of any history of trauma. Radiological examinations demonstrated an osseous mass originating from the epiphysis of the proximal tibia, with a continuous osteoblastic lesion involving the lateral half of the epiphysis. The pathological diagnosis of these lesions was compatible with that of osteochondroma. The clinical and pathological features of this case were considered to be identical with those of dysplasia epiphysealis hemimelica, although this patient was older than patients described in previous reports, and demonstrated no other symptoms such as valgus or varus deformity or limb-length discrepancy.     

Paget disease of the anterior tibial tubercle

A study was done of 13 cases of biopsy-proved Paget disease in which the disease involved the anterior tibial tubercle with extension into the metaphysis and diaphysis, but without apparent involvement of the proximal tibial epiphysis. Case data were obtained from archives containing more than 350 cases of Paget disease. Age, sex, symptoms, serum alkaline phosphatase level, and histologic and radiographic appearance of the lesions were evaluated. Patients were young at clinical presentation, averaging 36 years of age. In five of six patients the serum alkaline phosphatase level was normal. The proximal extent of the disease was the anterior tibial tubercle rather than the proximal epiphysis. Radiographic patterns ranged from predominantly lytic to mixed lytic and blastic to predominantly blastic, and the lesion was marginated by a flame-shaped configuration. The radiographic appearance of Paget disease of the anterior tibial tubercle is characteristic and should be sufficient to suggest the diagnosis and preclude biopsy.     

Value of computed tomography in planning medical and surgical treatment of chronic osteomyelitis

The contributions of computed tomographic (CT) images to the planning of medical and surgical treatment of osteomyelitis were assessed in seven patients. The scans helped medical therapy in two cases by guiding nonsurgical percutaneous biopsy of infected tissue, permitting prompt institution of proper antibiotics. The scans indicated the need for surgery and provided vital information on disease extent that helped plan the appropriate operation in five patients. Sequestra, medullary involvement, and the extent of sinus tracts that could not be seen on conventional imaging tests were detectable on CT. It is concluded that CT plays an important role in proper choices of both medical and surgical treatment in patients with osteomyelitis.     

Pericardial abscess occurring after tuberculous pericarditis: image morphology on computed tomography and magnetic resonance imaging

AIM: To study the image morphology on computed tomography (CT) and magnetic resonance imaging (MRI) of pericardial abscess, an uncommon complication of tuberculous pericarditis. MATERIAL AND METHODS: In a 9-year period, 120 patients with clinical and imaging features of constrictive pericarditis were retrospectively reviewed. Of them, 13 patients (age range, 1-51 years; seven females, six males), who had a pericardial mass on echocardiography, and were subjected to CT (11 patients) and MRI (7 patients), were included as subjects of the present study. Five patients underwent both the investigations. The intra-lesional morphology, location, extent, mass effect on adjacent cardiac chambers, secondary effects on the atria and venae cavae, and pericardial thickness were studied. Histopathological confirmation of tubercular infection was available in nine patients. In the remaining four patients, the diagnosis was based on typical extra-cardiac manifestations of tuberculosis. RESULTS: A total of 15 abscesses were detected. CT showed a lesion with a hypodense core and an enhancing rim in all patients. On spin-echo T1-weighted MRI, 57% of the paients had a lesion with a hyperintense core, suggesting an exudative process. Seventy-one percent of patients showed a lesion with a hyperintense core on T2-weighted MRI, while one lesion was hypointense. Post-gadolinium MRI was performed in two patients and showed an enhancing rim in both, with enhancing septa in one. The predominant site of involvement was in the right atrioventricular (AV) groove (77%). Localized tamponade, suggested by the presence of mass effect on an adjacent cardiac chamber, was noted in nine (69%) cases, with proximal atrial dilatation in 78% of them. Four other patients (31%) had atrial dilatation without a localized mass effect. CONCLUSION: Pericardial abscess is an uncommon complication of constrictive pericarditis. Tuberculosis was responsible for abscess formation in all cases in this study. The majority of the lesions are located in the right AV groove with imaging features suggestive of localized tamponade. The presence of a hypointense core on T2-weighted MRI may suggest a tubercular aetiology.     

The value of ultrasound and aspiration in differentiating vaso-occlusive crisis and osteomyelitis in sickle cell disease patients.

We have studied 50 patients with sickle cell disease who presented with musculoskeletal pain over a 2-year period to assess the use of ultrasound in differentiating infection from infarction. All the patients were evaluated by ultrasound. Five had soft tissue oedema and no fluid collection adjacent to the bone. Forty-five had a subperiosteal fluid collection. Twelve patients whose collections were not aspirated were diagnosed according to clinical evaluation. The remaining 33 patients underwent aspiration under ultrasound guidance to distinguish between an infection and infarction. Twenty-three of these were diagnosed as osteomyelitis and 10 as vaso-occlusive crises. In 21 out of the 23 infected cases, the fluid collection was greater than 10 mm at its thickest point perpendicular to the bone surface and all those with infarction had fluid less than 10 mm thickness. Aspiration under ultrasound guidance is a useful method to differentiate the two clinical entities. In patients suffering from osteomyelitis, identification of the organisms guides antibiotic administration. Needle decompression can help to relieve pain in osteomyelitis and vaso-occlusive crisis.     

Comparison of indium-111 nonspecific polyclonal IgG with indium-111-leukocytes in a canine osteomyelitis model

Osteomyelitis was surgically produced in the proximal tibia of ten dogs. A sham operation was performed on the other tibia. Early (3 hr) and late (20 hr) imaging was performed 1, 4, 7, 10, and 13 wk later, while the osteomyelitis progressed from acute to chronic. Indium-111-IgG had a significantly greater accumulation at the osteomyelitis site than 111In-leukocytes, both during early (p = 0.001) and late (p = 0.03) imaging, and at each of the weeks studied (p less than 0.001). During early imaging, both agents gave equivalent lesion to background ratios. On the late images, the 111In-leukocytes gave significantly higher lesion-to-background ratios than 111In-IgG (p less than 0.001) and higher ratios than they did during the early images (p less than 0.001). Both agents had greater accumulation in acute osteomyelitis than in chronic osteomyelitis (p less than 0.02). Osteomyelitis in the surgical site can be distinguished from the uptake in the sham surgery site using 111In-leukocytes, but not when using 111In-IgG.     

The use of SPECT in the diagnosis of epiphyseal osteoid osteoma

An osteoid osteoma, which rarely occurs in an intraepiphyseal site, was identified by SPECT imaging in the proximal tibial epiphysis of a boy who had lower back pain, which had not been explained prior investigations.     

小儿长骨骨髓炎的MRI表现

目的：探讨不同年龄组间小儿长骨骨髓炎的MRI表现。方法：在我院确诊为血源性骨髓炎并行MRI检查者38例;按年龄分成A组（年龄≤18个月）和B组（年龄〉18个月）。分析比较两组患者的临床表现、部位、病灶在长骨中的部位（骨骺、干骺端或骨干）、病灶信号、骨膜下脓肿、关节积液等。采用SPSS19．00软件进行统计学分析。结果：本研究中病变最常累及的部位：A组为股骨（52．3％）,B组为胫骨（50．0％）,两组间差异无统计学意义（P〉0．05）。A组中累及干骺及骨骺者占81．0％,在B组中累及千骺端及骨骺者占50．0％,累及干骺端及骨干者占30．0％,两组间差异无统计学意义（P〉O．05）。低年龄组中炎症累及骨骺的发生率与高年龄组间的差异有统计学意义（P％0．05）。A组中合并关节炎者占81．0％,B组中为45．0％,两组间差异有统计学意义（P〈O．05）。结论：小儿长骨骨髓炎的主要MRI表现为病变多位于干骺端,常合并软组织炎症;小于18个月的幼儿骨髓炎易向骺侧扩散而并发关节炎,而大于18个月的儿童骨髓炎更易于向骨干延伸。     

The diabetic foot: initial experience with 18F-FDG PET/CT.

Osteomyelitis complicates up to one third of diabetic foot infections, is often due to direct contamination from a soft-tissue lesion, and represents a clinical challenge. Early diagnosis is important since antibiotic therapy can be curative and may prevent amputation. The present study assessed the role of PET/CT using 18F-FDG for the diagnosis of diabetic foot osteomyelitis. METHODS: Fourteen diabetic patients (10 men and 4 women; age range, 29-70 y) with 18 clinically suspected sites of infection underwent PET/CT after the injection of 185-370 MBq of 18F-FDG for suspected osteomyelitis complicating diabetic foot disease. PET, CT, and hybrid images were independently evaluated for the diagnosis and localization of an infectious process. Additional data provided by PET/CT for localization of infection in the bone or soft tissues were recorded. The final diagnosis was based on histopathologic findings and bacteriologic assays obtained at surgery or at clinical and imaging follow-up. RESULTS: PET detected 14 foci of increased 18F-FDG uptake suspected as infection in 10 patients. PET/CT correctly localized 8 foci in 4 patients to bone, indicating osteomyelitis. PET/CT correctly excluded osteomyelitis in 5 foci in 5 patients, with the abnormal 18F-FDG uptake limited to infected soft tissues only. One site of mildly increased focal 18F-FDG uptake was localized by PET/CT to diabetic osteoarthropathy changes demonstrated on CT. Four patients showed no abnormally increased 18F-FDG uptake and no further evidence of an infectious process on clinical and imaging follow-up. CONCLUSION: 18F-FDG PET can be used for diagnosis of diabetes-related infection. The precise anatomic localization of increased 18F-FDG uptake provided by PET/CT enables accurate differentiation between osteomyelitis and soft-tissue infection.     

Sports-related epiphyseal injuries of the lower extremity. An epidemiologic study.

Sports-related epiphyseal injuries in children and adolescents have been becoming more prevalent during recent years. We report 85 patients with epiphyseal fractures of the lower extremity treated in our hospital during the last twenty years, of which 60 were males and 25 females with an average age of 12.6 years (range 4 to 17 years of age). The injuries were sustained during soccer in 28% and during alpine skiing in 26% of the cases, of which the former was responsible for most of the injuries reported in males and the latter for those in females. The most frequently seen localizations were in the distal tibial epiphysis (31 cases), followed by the distal fibula (17) and the proximal tibial epiphysis (15). Of the reported 85 epiphyseal fractures 30 were Salter-Harris type I injuries, 25 type II, 8 type III and 11 were type IV fractures, while 11 were avulsion fractures. Of these patients, 56% were treated surgically, while conservative treatment was chosen for 44% of the patients. Of the 49 patients available for follow-up, complications were documented in 9 instances, including 3 leg length discrepancies, 4 axis deviations, one avascular necrosis of the femoral head and one case of osteomyelitis, of which 6 required corrective surgery.     

Circumscribed non-tuberculous osteomyelitis in children. Apropos of 31 cases

Over the last eight years (1975-1983) a total of 31 cases of circumscribed non-tuberculous osteomyelitis in children have been treated as against 21 cases of classical acute osteomyelitis, suggesting transformation of the mode of presentation of this disease. Lesions were located in the pelvis (8 cases), the calcaneum (3 cases) and the long bones (20 cases), the metaphysis being affected in the latter in 13 patients, the diaphysis in 4 and the epiphysis in three. Specific radiologic images for each location are defined. Clinical expression was subacute and signs of infection inconstant. Differential diagnosis is discussed in relation to each region involved, a positive diagnosis depending on clinical, biologic and radiologic findings, with the need for biopsy in case of doubt. The latter was necessary in 12 of the 31 children. Diagnosis was confirmed in all cases by the favorable outcome from treatment.     

Diagnostic imaging and therapy of chondroblastoma

The chondroblastoma is a rare lytic osseous lesion, which is typically to be found in the epiphyses of the long tubular bones. We present a case report with the differential diagnostic imaging and the surgical therapy of a chondroblastoma of the proximal tibial epiphysis. A 16-year-old male presented in the traumatological accident and emergency centre with knee pain of unclear origin that had been increasing for several months. He had no memory of any acute trauma. For further clarification, a conventional radiograph in two planes, a thin-layer CT, a multiplanar MRI before and after Gd-DTPA, and a bone scan were performed. The conventional radiological diagnostics show a smoothly circumscribed, osteolytic, eccentric lesion with marginal sclerosis, which not exceeds the epiphyseal seam of the proximal tibia. The thin-layer CT reveals an eccentric osteolysis, with a typical, narrow sclerotic seam and central calcifications. In the high-resolution MRI, the T2-weighted sequences show a locally limited, epiphyseal, lobulated lesion with a heterogeneous, in part raised signal. A further signal increase can be seen in the T1-weighted sequences after administration of Gd-DTPA. Perifocally, there is an epiphyseal edema and discrete (intraarticular fluid collection) fluid in the inner knee. In the skeletal scintigraphy, there is a strong focal and diffuse increased activity from the proximal, lateral tibial epiphysis. After the diagnosis had been rendered, curettage of the defect was performed and then, after histological confirmation of the diagnosis, completing spongiosaplasty was conducted. Taking into account the localisation and the patient's age, a virtually certain diagnosis can already be rendered using conventional imaging. A supplementary MRI or CT can be helpful for final clarification, while 3-phase skeletal scintigraphy is superfluous. The therapy of choice is curettage and subsequent filling of the defect with autologous spongiosa.