ABSTRACT
OBJECTIVE: We describe four cases of osteomyelitis that occurred in and around foci of preexisting osteonecrosis in the medullary cavity. Although sequestration is a well-known complication of osteomyelitis, there is little information known about infection occurring in proximity to large regions of already necrotic bone. CONCLUSION: Osteomyelitis and bone infarction can be seen in the same patient population. Medullary infarcts may function as sequestra, predisposing patients to osteomyelitis and soft-tissue infection.
Subject(s)
Bone and Bones/blood supply , Infarction/complications , Osteomyelitis/etiology , Adolescent , Adult , Bone and Bones/diagnostic imaging , Bone and Bones/pathology , Child , Female , Humans , Infarction/diagnostic imaging , Infarction/pathology , Magnetic Resonance Imaging , Male , Middle Aged , Osteomyelitis/diagnostic imaging , Osteomyelitis/pathology , Osteonecrosis/complications , Osteonecrosis/diagnostic imaging , Osteonecrosis/pathology , Tomography, X-Ray ComputedABSTRACT
OBJECTIVE: To assess the impact of flip angle with gradient sequences on the "magic angle effect". We characterized the magic angle effect in various gradient echo sequences and compared the signal-to-noise ratios present on these sequences with the signal-to-noise ratios of spin echo sequences. DESIGN: Ten normal healthy volunteers were positioned such that the flexor hallucis longus tendon remained at approximately at 55 degrees to the main magnetic field (the magic angle). The tendon was imaged by a conventional spin echo T1- and T2-weighted techniques and by a series of gradient techniques. Gradient sequences were altered by both TE and flip angle. Signal-to-noise measurements were obtained at segments of the flexor hallucis longus tendon demonstrating the magic angle effect to quantify the artifact. Signal-to-noise measurements were compared and statistical analysis performed. Similar measurements were taken of the anterior tibialis tendon as an internal control. RESULTS AND CONCLUSIONS: We demonstrated the magic angle effect on all the gradient sequences. The intensity of the artifact was affected by both the TE and flip angle. Low TE values and a high flip angle demonstrated the greatest magic angle effect. At TE values less than 30 ms, a high flip angle will markedly increase the magic angle effect.
Subject(s)
Artifacts , Magnetic Resonance Imaging , Tendons/anatomy & histology , Adult , Ankle/anatomy & histology , Ankle Joint/anatomy & histology , Humans , MaleABSTRACT
In a bilateral canine tibial model, the mechanical, radiologic, and histologic characteristics of intercalary allografts stabilized with locked intramedullary nails were compared with those of allografts fixed with compression plates. Both methods of fixation achieved healing to host bone. Tibiae that were plated had more callus with statistically greater mean torsional rigidity and strength than those treated with nails (paired t-test, p = 0.05). On average, tibiae which had been plated had much higher bending rigidity than those fixed with locked nails; however, the difference in means was not statistically significant. Histomorphometric analysis showed an overall greater total bone formation in those limbs treated with plates compared to nails (paired t-test, p = 0.04). The mechanical environment created by the different fixation methods are thought to be responsible for the observed differences in healing pattern. The traditional concept of fixation for allografts to achieve maximum rigidity of the construct may not necessarily promote the most appropriate host healing response in all situations. A less rigid fixation method (plates) produced more callus resulting in superior torsional and bending properties. These data show that in this canine intercalary allograft model, limbs fixed with plates produced more external callus resulting in stronger, more rigid healing.
Subject(s)
Bone Nails , Bone Transplantation , Tibia/surgery , Animals , Biomechanical Phenomena , Bone Plates , Dogs , Osseointegration , Tibia/pathology , Transplantation, HomologousABSTRACT
Filariasis is a world health problem that is frequently seen in tropical and subtropical countries. In endemic areas, the clinical spectrum of extremity swelling, lymphangitis, or elephantiasis is usually recognized as filariasis. In the United States, diagnosis of the disease may be more difficult because of lack of familiarity with this infection. We present a case of filaremic arthropathy of the ankle joint and the magnetic resonance imaging (MRI) findings of this disease. It is the first reported case of MRI findings in a human patient. MRI has been done on animal models with filariasis, and the findings are similar.
Subject(s)
Ankle Joint/parasitology , Filariasis/diagnosis , Joint Diseases/parasitology , Magnetic Resonance Imaging , Adult , Animals , Female , Guyana/ethnology , Humans , Joint Diseases/diagnosis , United StatesABSTRACT
Filariasis is a world health problem that is frequently seen in tropical and subtropical countries. In endemic areas, the clinical spectrum of extremity swelling, lymphangitis, or elephantiasis is usually recognized as filariasis. In the United States, diagnosis of the disease may be more difficult because of lack of familiarity with this infection. We present a case of filaremic anthropathy of the ankle joint and the magnetic resonance imaging (MRI) findings of this disease. It is the first reported case of MRI findings in a human patient. MRI has been done on animal models with filariasis, and the findings are similar. (AU)
Subject(s)
Adult , 21003 , Case Reports , Female , Humans , Filariasis/diagnosis , Joint Diseases/parasitology , Magnetic Resonance Imaging , Ankle Joint/parasitology , Guyana/ethnology , Joint Diseases/diagnosis , United StatesABSTRACT
STUDY DESIGN: The analysis of the imaging characteristics found in chronic odontoid fractures. OBJECTIVES: To determine the efficacy of computed tomography and magnetic resonance imaging in diagnosing a chronic odontoid fracture. SUMMARY OF BACKGROUND DATA: Radiographic examination of the cervical spine is intrinsic to the evaluation of all patients with blunt trauma. Injury to the craniocervical junction constitutes 19-25% of all cervical spine fractures. At the authors' trauma center computed tomography is routinely used instead of the open-mouth odontoid radiograph to facilitate cervical spine evaluation. This practice has increased the detection of fractures that are unrecognized in plain radiography, and has, at the same time, raised questions about the age and significance of these fractures. METHODS: Radiography, computed tomography, and magnetic resonance imaging studies were performed on three patients who came to the emergency department with odontoid fractures. Two patients had a history of severe trauma, and one had a history inconsistent with an acute odontoid fracture. One patient also had a technetium Tc 99m methylene dihydroxyphosphonate bone scan. The studies were obtained to determine the age of the fractures. RESULTS: All three patients were determined to have chronic odontoid fractures. This diagnosis was facilitated by the use of computed tomographic and magnetic resonance imaging. Computed tomography showed increased sclerosis in the proximal fracture fragment in all cases and well-corticated fracture edges in one patient. Magnetic resonance images showed normal bone marrow or bone sclerosis in the odontoid process. Soft tissue edema was absent. A bone scan was not useful in resolving this issue. CONCLUSION: Computed tomography and magnetic resonance imaging can be useful in determining the chronicity of an odontoid fracture.
Subject(s)
Cervical Vertebrae/injuries , Odontoid Process/injuries , Spinal Fractures/diagnosis , Aged , Cervical Vertebrae/diagnostic imaging , Cervical Vertebrae/pathology , Chronic Disease , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Odontoid Process/diagnostic imaging , Tomography, X-Ray ComputedABSTRACT
The objective of this article was to delineate the causes of avascular necrosis (AVN) in patients with human immunodeficiency virus (HIV). HIV-infected patients with pain in large joints were prospectively screened. Patients had radiographs and magnetic resonance imaging of their affected joints. Serum lipids, anticardiolipin antibody levels (IgG, IgM), and hemoglobin electrophoresis were performed on all patients who had radiographic studies. Medical records were screened for factors known to predispose for AVN. Eight patients completed the protocol, and five patients had AVN in seven joints. No common laboratory abnormality was identified in the patients with AVN. All of the patients with AVN had a history of steroid use; four of five patients having taken steroids for HIV-related diseases. The cause of AVN does not appear to be directly related to the disease, but to steroid treatment for manifestations of the disease.
Subject(s)
HIV Infections/complications , HIV , Hip Joint/pathology , Magnetic Resonance Imaging , Osteonecrosis/etiology , Shoulder Joint/pathology , Adult , Arthrography , Diagnosis, Differential , Female , HIV Infections/diagnosis , Humans , Male , Middle Aged , Osteonecrosis/diagnosis , Prospective Studies , Shoulder Joint/diagnostic imagingABSTRACT
OBJECTIVE: This study uses magnetic resonance (MR) imaging to delineate the types and frequencies of injuries seen in the knee after ipsilateral femoral shaft fracture. We also compare the results of the orthopedic knee examination with the MR findings. DESIGN AND PATIENTS: MR imaging of the ipsilateral knee was performed on 34 patients with closed femoral shaft fractures. Indications for knee MR imaging included knee pain at the time of fracture, soft tissue swelling or an effusion of the knee, or a positive knee examination under anesthesia. The patients had a mean age of 27 years and all were stabilized with intramedullary nails. Imaging was performed a mean time of 2.5 days after surgery. All patients had knee examinations done under anesthesia, and the MR results were compiled and compared with the clinical examinations. RESULTS: Ninety-seven percent of patients demonstrated knee effusions. Twenty-seven percent of patients demonstrated meniscal tears, with the posterior horn of the medial meniscus most frequently torn. The medial collateral ligament was the most frequent site of ligamentous injury (38%) followed by the posterior cruciate ligament (21%). Fifty percent of patients had injuries of the extensor mechanism. Bone bruises were noted in 32% of patients. Articular cartilage injuries were confined to the patella in four cases. One occult tibial plateau fracture and one meniscocapsular separation were seen. CONCLUSIONS: There is a common incidence of both ligamentous and meniscal injury to the knee after ipsilateral femoral shaft fracture. MR imaging can be useful in assessing the extent of injury, and may reveal findings unsuspected after clinical examination of the knee.
Subject(s)
Femoral Fractures/complications , Knee Injuries/etiology , Knee Injuries/pathology , Magnetic Resonance Imaging , Adult , Anterior Cruciate Ligament Injuries , Female , Femoral Fractures/pathology , Humans , Knee/pathology , Male , Posterior Cruciate Ligament/injuries , Tendon Injuries/etiology , Tendon Injuries/pathology , Tibial Meniscus InjuriesABSTRACT
We describe an Egyptian boy with osteogenesis imperfecta who was born with thumb contractures and bilateral antecubital pterygia. He was seen at 16 months of age with femur and tibial fractures, thoracic vertebral compression fractures, scoliosis and Wormian bones. The findings are consistent with a diagnosis of Bruck syndrome.
Subject(s)
Contracture/complications , Contracture/diagnostic imaging , Joint Diseases/complications , Joint Diseases/diagnostic imaging , Osteogenesis Imperfecta/complications , Osteogenesis Imperfecta/diagnostic imaging , Abnormalities, Multiple , Contracture/congenital , Humans , Infant , Joint Diseases/congenital , Male , Radiography , SyndromeABSTRACT
PURPOSE: Our objective was to examine the MR characteristics of synovial sarcoma and determine the frequency of a nonaggressive imaging appearance. METHOD: Fifteen patients with histologically confirmed cases of synovial sarcoma and prior MR examinations were seen. Retrospective analysis of imaging features included assessment of size, margins, homogeneity, internal architecture, T1- and T2-weighted signal intensities, and bone invasion. RESULTS: Five of 15 patients (33%) had well circumscribed, homogeneous lesions with a mean length of 4.8 cm. The T1-weighted signal intensity was either isointense to muscle or greater in signal intensity than muscle. The T2-weighted images demonstrated signal intensity equal to or greater than fat. The remaining 10 lesions were larger (mean length of 11.3 cm) with mild to complex levels of inhomogeneity and margins that varied from well circumscribed to infiltrating. CONCLUSION: There are two sets of MR features seen with synovial sarcoma. Small lesions of -5 cm can demonstrate a nonaggressive appearance with well circumscribed margins and homogeneous signal intensity. These tumors could be confused with benign lesions, resulting in inappropriate surgical intervention like excisional biopsies through transverse incisions. This would make future surgery more difficult. Larger lesions tend to be more heterogeneous in signal intensity.
Subject(s)
Magnetic Resonance Imaging , Sarcoma, Synovial/pathology , Adipose Tissue/pathology , Adolescent , Adult , Aged , Axilla/pathology , Bone Neoplasms/pathology , Child , Contrast Media , Female , Foot Diseases/diagnosis , Foot Diseases/pathology , Foot Diseases/surgery , Humans , Image Enhancement/methods , Joint Diseases/diagnosis , Joint Diseases/pathology , Joint Diseases/surgery , Knee Joint/pathology , Leg , Magnetic Resonance Imaging/methods , Male , Middle Aged , Muscle, Skeletal/pathology , Neoplasm Invasiveness , Pelvic Neoplasms/pathology , Retrospective Studies , Sarcoma, Synovial/diagnosis , Sarcoma, Synovial/surgery , Thigh/pathologyABSTRACT
This report describes the case of a ganglion cyst of the anterior cruciate ligament in a 26-year-old man who had long-standing intermittent knee pain with locking. The cyst was successfully aspirated under computed tomography guidance, with complete resolution of symptoms. A literature review is presented along with diagnostic and treatment approaches for this uncommon finding.
Subject(s)
Anterior Cruciate Ligament , Popliteal Cyst/surgery , Radiography, Interventional/methods , Tomography, X-Ray Computed , Adult , Humans , Male , Popliteal Cyst/diagnostic imaging , SuctionABSTRACT
OBJECTIVE: Radiographic evaluation of the upper cervical spine in patients who have suffered severe trauma is often problematic because of the difficulty of obtaining adequate open-mouth views of the odontoid in these critically ill patients. This study was undertaken to determine the frequency and clinical significance of upper cervical spine fractures detected by CT in this patient population. MATERIALS AND METHODS: The study group consisted of 100 consecutive patients brought to the emergency department after severe trauma who had CT of the craniocervical junction done instead of an open-mouth view. Plain film evaluation consisted of a cross-table lateral view, an anteroposterior view, and, if necessary, a swimmer's view. The radiographic studies were reviewed retrospectively by a musculoskeletal radiologist and a neuroradiologist, respectively. Hospital records were reviewed to ascertain the patients' clinical signs and symptoms on admittance and to determine how identification of the fractures changed the treatment plan. RESULTS: Eight fractures in seven patients were identified with CT of the craniocervical junction. Three of the fractures were of the occipital condyle, and five were at the C1-C2 level. None of the fractures were seen directly on plain radiographs, although secondary signs of injury such as prevertebral soft-tissue swelling were seen in two of the seven cases. CONCLUSION: CT of the craniocervical junction revealed an 8% frequency of fractures of the occipital condyle and C1-C2 that were undetected on the cross-table lateral cervical spine radiographs. Fractures occurred in greater numbers than expected, and all surviving patients were stabilized with a halo. This experience shows that CT is an efficient method of evaluating patients in whom the standard open-mouth radiograph of the odontoid cannot be done.
Subject(s)
Cervical Vertebrae/injuries , Spinal Fractures/diagnostic imaging , Adolescent , Adult , Aged , Aged, 80 and over , Cervical Vertebrae/diagnostic imaging , Child , Child, Preschool , Female , Humans , Male , Middle Aged , Neck Injuries , RadiographyABSTRACT
Four patients with intraosseous lipomas were studied with magnetic resonance imaging. The imaging features and histology of each tumor were compared. Magnetic resonance imaging was very helpful in establishing a pathologic diagnosis. If a severe degree of involution was present, then the magnetic resonance findings could be ambiguous, making diagnosis more difficult.
Subject(s)
Bone Neoplasms/diagnosis , Bone Neoplasms/pathology , Leg , Lipoma/diagnosis , Lipoma/pathology , Magnetic Resonance Imaging , Adipose Tissue/pathology , Adult , Biopsy , Calcinosis/pathology , Contrast Media , Female , Femoral Neoplasms/diagnosis , Femoral Neoplasms/pathology , Fibula/pathology , Humans , Image Enhancement , Ischemia/pathology , Male , Middle Aged , Neoplasm Staging , Retrospective Studies , Tibia/pathologySubject(s)
Bone Diseases/diagnosis , Foot Diseases/diagnosis , Magnetic Resonance Imaging , Sarcoidosis/diagnosis , Adult , Female , HumansABSTRACT
A patient with a synovial sarcoma of the foot and several unusual radiographic findings has been reported. Radiographs demonstrated lamellated periosteal reaction in a metatarsal, a rare finding in cases of synovial sarcoma. Magnetic resonance scanning documented marrow invasion of multiple bones in the foot, when bony involvement has been reported as only erosive changes.
Subject(s)
Foot Diseases/diagnosis , Sarcoma, Synovial/diagnosis , Adult , Foot Diseases/pathology , Humans , Magnetic Resonance Imaging , Male , Sarcoma, Synovial/pathology , Tomography, X-Ray ComputedABSTRACT
The differential diagnosis for lytic intracortical lesions consists primarily of osteoid osteoma and Brodie's abscess. A third, less-well-known lesion is the intracortical hemangioma. It has an identical appearance to the two aforementioned lesions on bone scan and radiographs. This case report will describe the magnetic resonance imaging appearance of intracortical hemangioma and how it might be differentiated from osteoid osteoma and Brodie's abscess.
Subject(s)
Bone Neoplasms/diagnosis , Hemangioma, Cavernous/diagnosis , Ulna , Abscess/diagnosis , Adult , Bone Neoplasms/pathology , Diagnosis, Differential , Female , Hemangioma, Cavernous/pathology , Humans , Magnetic Resonance Imaging , Osteoma, Osteoid/diagnosis , Radionuclide ImagingABSTRACT
The airbag restraint system has been described as a means of reducing fatalities in frontal crashes. This conclusion is based on crash investigations and statistical extrapolation, but few data exist to document specific fracture patterns and injuries after airbag deployment. Seven cases of driver's side airbag deployment after motor vehicle crashes were studied for extent of injury. Unrestrained (non-seatbelted) drivers demonstrated flexion injuries of the cervical and thoracic spine and direct impaction fractures of the face and sternum. One restrained (lap-shoulder belt) driver demonstrated an extension injury of the upper cervical spine. What may emerge from further study is a decrease in fatalities, but also a pattern of fractures specific to airbag use.
Subject(s)
Accidents, Traffic , Air Bags , Fractures, Bone/etiology , Wounds and Injuries/etiology , Accidents, Traffic/statistics & numerical data , Adolescent , Adult , Air Bags/classification , Air Bags/statistics & numerical data , Biomechanical Phenomena , Female , Fractures, Bone/diagnosis , Fractures, Bone/epidemiology , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Seat Belts/statistics & numerical data , Tomography, X-Ray Computed , Wounds and Injuries/diagnosis , Wounds and Injuries/epidemiologyABSTRACT
Bone graft subsidence is a serious complication of interbody spinal fusion. In this study, 66 mechanical tests were performed on 35 thoracic vertebral bodies to investigate the in situ mechanics of interbody spinal fusion. The relationships among trabecular bone density, bone strength, and size of bone graft area were analyzed. All vertebral bodies were scanned by quantitative computer tomography (QCT) to determine their bone density before mechanical testing. The decorticated trabecular beds of the vertebral bodies, void of all posterior elements, were loaded in a manner similar to that which occurs after surgical interbody fusion. That is, rectangular blocks of polymethylmethacrylate, representing bone grafts, were used to transfer controlled compressive loads to the decorticated vertebral trabecular surface. Both destructive and nondestructive tests were performed. The relationship between QCT bone density and trabecular bone strength was related by a power function, and, on average, the bone density and trabecular bone strength were 0.137 g/cm3 and 3.97 MPa, respectively. Eighty percent of the vertebral bodies with graft covering 25% of the total end plate area or less failed at loads less than 600 N, while 88% of the vertebral bodies with 30% or greater covered were able to carry a load greater than 600 N. The results suggest that the intrinsic behavior of trabecular bone loaded within the vertebral body is little different from the behavior of the whole body, that QCT bone density is indicative of bone strength, and that interbody graft area should be significantly greater than 30% of the total end plate area to provide a margin of safety.(ABSTRACT TRUNCATED AT 250 WORDS)