Diffuse lymphangiomatosis of bone

Two cases of lymphangiomatosis of bone, a very rare systemic condition characterized by both skeletal and parenchymal lesions, are presented. The skeletal changes have an appearance similar to haemangiomas in the spine, and soap-bubbly lesions in the flat bones. One case carried the diagnosis of eosinophilic granuloma for 18 years. The findings on MRI, which have not been previously well-established, are discussed.

Calcaneal fractures in diabetic patients

We would like to present 23 calcaneal fractures in 22 patients of whom 21 had type I diabetes mellitus. There appear to be three basic fracture types: (1) a superiorly displaced extra-articular avulsion fracture of the posterior calcaneus (or Iowa fracture), which occurred in 12 patients (five men, seven women); (2) a mid-calcaneal compression fracture in six patients (four men, two women), and (3) a cleavage or "wedge" type fracture in four patients extending from the calcaneal tubercle (one man, 3 women). All four of this last group of patients had a history of a chronic penetrating ulcer, and this is noteworthy since only one other patient out of the remaining 18 in groups 1 and 2 had a similar history. Most patients had decreased bone mineralization: 15 patients were on long-term, high-dose steroids, and 18 patients had either poor renal function or complete renal failure (11 of 12). Fourteen patients had received either renal or pancreas transplants. Eight patients were on restricted weight bearing prior to their fractures. We believe that diabetic patients are more prone to calcaneal fractures than the general population, and early diagnosis is imperative, followed by early treatment to prevent significant bony deformity.

Effects of capsular contracture on ultrasonic screening for silicone gel breast implant rupture

Unlike computed tomography and magnetic resonance imaging, ultrasound is an inexpensive test of potential use in detecting silicone gel breast implant (SBI) rupture. However, periprosthetic capsular contracture can make ultrasonic diagnosis of rupture difficult because the contracture-related radial folds inside the SBI can lead to a false-positive diagnosis of rupture. This study was conducted to determine the effects of capsular contracture on the ability of ultrasound to diagnose SBI rupture. Preoperative ultrasonic results of 122 SBIs were compared with surgical findings at the time of implant removal. The sensitivity and negative predictive values of ultrasound were lower in the presence of a contracted capsule (41.2% vs. 68.7%, p = 0.062; and 58.3% vs. 79.6%, p = 0.056 respectively). Ultrasound should be considered reliable in diagnosing SBI rupture only in the absence of a contracted capsule.

The use of MR imaging in the assessment and clinical management of stress reactions of bone in high-performance athletes

Based on experience, the authors believe that MR imaging is a useful tool in the assessment and management of stress fractures and stress phenomenum of bone. The use of standard, graded MR evaluation aides the assessment of a repetitive stress injury to bone by allowing a more accurate diagnosis of bone injury. This more accurate assessment has predictive value in estimating the duration of disability. The use of a standard, graded MR evaluation aides the management of repetitive stress injuries to bone by defining a low grade of stress fracture (i.e., grade 1 and 2) injuries and a high grade of stress fracture (i.e., grade 3 and 4). This grading system has implications in the management of stress fractures, allowing more individualized treatment for the elite athlete.

The prevalence of diffuse idiopathic skeletal hyperostosis (DISH) in two large American Midwest metropolitan hospital populations

OBJECTIVE

There are no published large-scale studies of the overall prevalence of diffuse idiopathic skeletal hyperostosis (DISH) and it has been proposed that the prevalence is greater than previously reported. We thus decided to review chest radiographs in a population of patients over 50 years of age seen at two large but differing metropolitan hospitals in a major American Mid-west city.

DESIGN AND PATIENTS

The posterior-anterior and lateral chest radiographs of 1363 patients were reviewed for evidence of DISH at the University of Minnesota Hospital and Clinic. There were 500 consecutive inpatient admissions, 540 consecutive patients who attended the outpatient clinics and 326 patients collected from our film archive. A population of 1001 patients seen at Hennepin County Medical Center was also studied. It was possible to subclassify this latter group with respect to race.

RESULTS AND CONCLUSION

Using strict criteria, i.e., four or more levels involved, the overall prevalence of DISH in the male population over age 50 years was 25% and in the female population over age 50 years was 15%. This prevalence climbed to 28% in males over 80 years and to over 35% in males over age 70 years. In females over 80 years, the prevalence was found to be 26%. Although our population base was small, DISH was found to be less common in the black, Native-American and Asian populations. The prevalence of DISH was also found to be far lower in a similar white population with osteoporosis. The overall prevalence of DISH was higher than expected in a predominantly white population over age 50 years with a lesser incidence in the black, Native-American and Asian populations, suggesting a genetic origin of the condition.

Use of MRI in evaluating postoperative changes in patients with bone and soft tissue tumors

We reviewed the clinical, surgical and magnetic resonance imaging (MRI) findings in 80 patients who underwent resection of primary benign or malignant bone or soft tissue tumors. There were 18 benign and 62 malignant tumors. Although 31 patients were originally thought to have recurrence, on review only 20 patients were considered to have recurred. Of these, three were found only to have postoperative changes at surgery. Seventeen patients actually had recurrence of tumor. We believe that the presence of an actual mass lesion on MRI is the cornerstone for the correct diagnosis of recurrent tumor.

The biomechanics of gravity-dependent traction of the lumbar spine

STUDY DESIGN

This study evaluated the biomechanical responses evoked by the use of a gravity-dependent, self-operated traction device. These responses were determined by radiographs and were correlated with the body weight of the patient who was supported by a seat strap.

OBJECTIVES

To examine the biomechanical effectiveness of the LTX 3000 Lumbar Rehabilitation System.

SUMMARY OF BACKGROUND DATA

The LTX 3000 Lumbar Rehabilitation System (Spinal Designs International, Minneapolis, MN) was used to administer the lumbar fraction. No previous study has been conducted on this device.

METHODS

For each of the 14 healthy male patients (age range, 19-69 years), lumbar lengthening, alterations in spinal curvature, and thoracic spine movement were assessed using radiographs taken: 1) before traction; 2) at 2, 10, and 15 minutes after the onset of traction; and 3) 2 minutes after traction was completed. Strain on the buttocks-supporting seat strap was recorded continuously during study sessions.

RESULTS

The entire patient pool displayed an average maximal lumbar lengthening of 6.39 +/- 4.21 mm. The amount of lumbar lengthening was influenced by the degree of thoracic immobilization and by the amount of prior LTX 3000 (Spinal Designs International) use. Significant curvature reduction was observed during and after traction for the entire patient pool. Strain measurements correlated well with the measured response in the radiographs.

CONCLUSIONS

Proper use of the LTX 3000 (Spinal Designs International) induces significant lumbar lengthening and curvature reduction in healthy patients. Measurements of body weight supported by the seat strap could help determine if thoracic immobilization has been achieved and if the patient is responding to the lumbar unloading.

"Incisura" of the ascending aorta and vascular pedicle width in the cardiac transplant patient

BACKGROUND

The purpose of this study was to evaluate three findings in cardiac transplant patients: the appearance, etiology, and incidence of "incisura" (a characteristic indentation) of the ascending aorta; the vascular pedicle width, which usually appears enlarged on standard chest radiographs; and clearing of the retrosternal clear space.

MATERIAL

Two hundred sixty-one cardiac transplantations were performed at the University of Minnesota before December 31, 1992. The appearance, etiology, and incidence of an incisura were studied; the vascular pedicle width was measured; and the rate of clearing of the retrosternal clear space was determined.

RESULTS

Forty-six percent of the patients whose ascending aorta could be visualized on the lateral chest radiogram showed an incisura. Approximately one third of the patients showed continued opacification of the retrosternal space postoperatively. The width of the vascular pedicle in this series of cardiac transplant patients measured 60.9 +/- 22.8 mm (standard deviation, 11.4 mm), in comparison to a normal of 48 +/- 5.0 mm.

CONCLUSIONS

An incisura of the ascending aorta and the widened vascular pedicle are normal postoperative chest radiographic findings in cardiac transplant patients and should not be misconstrued as abnormalities.

Lipoblastoma of the foot

Lipoblastoma is an uncommon benign lipomatous soft tissue mass of childhood, occurring most commonly in children less than 3 years of age. We present a case of lipoblastoma occurring in the foot of a 14-year-old boy and review the literature. The appearance of the mass on magnetic resonance imaging (MRI) is illustrated and is correlated with the findings at gross and microscopic pathological examination. A lobulated architecture, the presence of adipose tissue, thin nonenhancing septa, peripheral lobules of more immature and therefore less specific tissue, and a peripheral pseudocapsule were evident on MRI and at pathological examination.

Cyclops lesion

Postoperative impingement of the knee following ACL reconstruction does occur. MRI can be useful in the diagnosis of the patient who is not recovering as quickly as expected following surgical reconstruction. MRI allows the assessment of 1) tunnel position and alignment, 2) graft integrity, 3) the menisci for possible re-tear or extension of previous tears, and 4) joint for scar tissue and cartilaginous bodies either loose or fixed.

Hyperextension strain or "whiplash" injuries to the cervical spine

PURPOSE

To define "whiplash" radiologically.

MATERIAL AND METHODS

A full cervical spine radiographic series (including flexion and extension views) was reviewed in 40 patients with clinically proven "whiplash" injuries and compared to the radiographs in 105 normal controls. The level and degree of kinking or kyphosis, subluxation, and the difference in the amount of fanning between spinous processes on flexion and extension films were measured in each patient.

RESULTS

Localized kinking greater than 10 degrees and over 12 mm of fanning, often occurring at the level below the kinking or kyphosis, occurred mainly in the group of whiplash patients (sensitivity 81%, specificity 76%, accuracy 80%).

CONCLUSIONS

Localized kinking greater than 10 degrees and fanning greater than 12 mm are useful measurements by which to separate patients with true whiplash injuries from those with minor ligamentous tears. Flexion and extension views are essential to help define whiplash and other ligamentous injuries of the cervical spine.

Radiographic evaluation of the complications of long bone allografts

PURPOSE

To study the long-term results of long bone allografts in patients with benign and malignant bone tumors.

MATERIAL AND METHODS

Forty patients for whom full clinical and radiological information was held were investigated in order to assess the overall incidence of complications including fractures, nonunion, hardware problems, infections, and bone resorption.

RESULTS

There were four deaths; four more patients had distant metastases and one patient had a recurrent chondrosarcoma. Seventeen patients (42%) had either no complications (nine patients) or only minor ones (eight patients). Eleven patients (27%) sustained fractures of either their allograft (eight patients) or of their hardware (three patients). Hardware problems occurred in nine patients (22.5%), six of whom had serious problems requiring revision. The majority of the fractures and hardware problems occurred in younger male patients (82%). Infection occurred in five patients (12.5%), two of whom required revision, while two cases were superficial. Dissolution of the allograft occurred in 12 patients (30%), 7 of whom required removal of the allograft. Ten of these 12 patients were female.

CONCLUSION

The long-term survival of long bone allografts is not as good as generally reported if an adequate follow-up time period is used. Most of the fractures and hardware problems occurred in the younger active male patients, whose activities should probably be curtailed. Resorption of the allograft is another serious complication which appears to occur mainly in female patients and could possibly be controlled by chemotherapy.

Orthopedic complications

This overview of the complications encountered in orthopedic cases focuses on, among other things, complications of spinal surgery. The incidence of infection in spinal instrumentation and other orthopedic procedures is discussed and followed by a review of the complications of total joint replacement. Finally, a few words on the radiologist's responsibility for the reporting of orthopedic complications are given.

Total hip replacement and other orthopedic hip procedures

The history of total hip replacement including that of the Girdlestone procedure and resurfacing procedures is discussed. An overview of total hip replacement and its indications and complications forms the bulk of this section. Also, the use of porous-coated prostheses and endoprostheses as well as pins and plates is discussed and illustrated.

The radiology of bone allografts

Bone allograft surgery provides an attractive and effective solution to many orthopedic problems. Nevertheless, the entire process is technically demanding and associated with many potential complications of which infection is one of the most difficult to treat. Many advances have been made in the procurement and use of bone allografts, and further investigation should expand the applications of allograft surgery and continue to diminish the incidence of complications.

Radiologic case study. Multicentric reticulohistiocytosis

MRH is somewhat similar to, and probably occasionally mistaken for, psoriatic arthritis, Reiter's syndrome, or less frequently, rheumatoid arthritis. However, several important features distinguish MRH from the other arthritides. Rheumatoid arthritis more commonly involves the metacarpophalangeal joints, while MRH ordinarily affects the distal interphalangeal and proximal interphalangeal joints. Furthermore, MRH rarely exhibits the degree of articular osteopenia that is the hallmark of rheumatoid disease. While psoriatic arthritis and Reiter's often affect the DIP joints, they rarely display the symmetry of MRH. In addition, MRH does not demonstrate the periosteal new bone formation that is seen in both psoriatic arthritis and Reiter's syndrome. Hence, the diagnosis of MRH may be made with reasonable confidence on the radiologic findings alone, even before the cutaneous nodules appear, which can then be biopsied to confirm the diagnosis.

Diagnosis of breast implant rupture: imaging findings and relative efficacies of imaging techniques

OBJECTIVE

The purpose of this study was to compare the efficacies of mammography, sonography, CT, and MR imaging in the detection of breast implant rupture and to analyze the imaging findings.

SUBJECTS AND METHODS

Thirty-two women with 63 silicone breast implants participated in the study. All but one had signs and symptoms suggestive of rupture, and all had requested that their implants be removed before they were enrolled in this imaging study. All patients had film-screen mammography, sonography, CT, and MR imaging. Twenty-two ruptures were found at surgery; 21 were intracapsular and one was extracapsular. The relative efficacies of the imaging studies were determined, and the imaging findings were compared with the surgical results.

RESULTS

Of the 32 women with 63 implants, mammographic sensitivity for detecting implant rupture was only 23% but the specificity was 98%. Sonography had a higher sensitivity (59%), but its specificity was significantly lower (79%). CT had a sensitivity of 82% and a specificity of 88%. MR was the only imaging technique that consistently provided evidence that enabled the evaluation of intracapsular and extracapsular ruptures. The sensitivity and specificity of MR imaging were 95% and 93%, respectively.

CONCLUSION

Our results show that MR imaging is more sensitive and specific for the detection of breast implant rupture than is mammography, CT, or sonography.