Disc displacement patterns in lumbar anterior spondylolisthesis: contribution to foraminal stenosis.

PURPOSE: To describe the particular disc displacement pattern seen at MRI in patients with spondylolisthesis, and its potential contribution to foraminal stenosis. METHODS: 38 patients with symptomatic lumbar anterior spondylolisthesis and 38 sex and aged matched control patients with herniated disc disease, at corresponding disc space levels, were included for study. In each case note was made of the presence, absence and direction of disc displacement and also the presence and location of neural contact with the displaced disc. RESULTS: In 33 of 38 (86.8%) patients in the spondylolisthesis group, the vertical disc displacement was upward. In the control group only 3 patients (7.8%) had upward vertical disc displacement. 19 patients (53%) from the spondylolisthesis group had exit foraminal nerve root contact, compared to 7 patients (18.4%) from the control group. 27 control patients (71%) had contact within the lateral recess, compared to only 6 patients (17%) with spondylolisthesis. Differences for upward displacement were significant (p<0.05). CONCLUSION: Disc displacement in patients with spondylolisthesis is predominately in a cephalad and lateral direction. Although this disc displacement pattern can occur in patients without spondylolisthesis, its incidence is much greater in the subset of patients with concomitant spondylolisthesis. In the setting of acquired osseous narrowing of the exit foramen, this described pattern of disc displacement superiorly and laterally in spondylolisthesis increases the susceptibility of spondylolisthesis patients to radicular symptoms and accounts for the exiting nerve root being more commonly affected than the traversing nerve root.

Ultrasound-guided percutaneous drainage of meniscal cysts: preliminary clinical experience.

AIM: To evaluate the efficacy of ultrasound-guided percutaneous drainage of symptomatic meniscal cysts. MATERIALS AND METHODS: Patients with lateral knee joint tenderness and swelling and confirmed meniscal cyst on magnetic resonance imaging (MRI) were consecutively enrolled for ultrasound-guided percutaneous cyst aspiration. Cysts were injected with local anaesthetic and steroid before completion of procedure. All 18 patients (all male, average age 33 years) were subsequently followed up (average time 10 months) and meniscal cyst symptoms assessed by questionnaire. Fischer's exact test used to analyse the data. RESULTS: In every case the procedure was well tolerated, and each patient indicated that they would be willing to have a repeat procedure in the future. Ten patients reported complete resolution of symptoms secondary to therapeutic cyst aspiration and had resumed participation in high-performance sport. Two patients reported a satisfactory sustained response, reporting only occasional "twinges of pain". In the remaining six patients, symptoms returned after an initial pain-free period. The pain-free period ranged from 1-8 weeks. In this study, patient outcome did not significantly correlate with any meniscal cyst characteristic. CONCLUSION: Ultrasound-guided percutaneous aspiration of meniscal cysts is a well-tolerated, simple, and safe procedure. In this small patient series, it was associated with positive early results with favourable outcomes in the mid to long-term. It should be considered in patients unsuitable for surgical debridement or as an interim therapy if surgery is delayed or postponed.

Contribution of full-thickness supraspinatus tendon tears to acquired subcoracoid impingement.

AIM: To assess the relationship between the severity of full-thickness supraspinatus tendon tears and the development of subcoracoid impingement. MATERIALS AND METHODS: Fifty-one magnetic resonance imaging (MRI) shoulder examination reports with full-thickness supraspinatus tears were retrospectively identified and reviewed by two dedicated musculoskeletal radiologists. The appearances of the rotator cuff muscles, biceps tendon and the lesser tubercle were recorded. The acromio-humeral distance and the axial coraco-humeral distance were measured. The data were recorded and analysed electronically. RESULTS: The kappa values for inter-observer agreement were: 0.91 for acromio-humeral distance and 0.85 for coraco-humeral distance measurements. Twenty-six patients had significant retraction of the supraspinatus tendon, 85% (22 cases) of this group had imaging evidence of tear or tendonopathy of the subscapularis tendon. Twenty-five patients had no significant retraction of the supraspinatus, 56% (14 cases) of this group had imaging evidence of a subscapularis tear or tendonopathy. The acromio-humeral distance was significantly less in patients with supraspinatus tears and retraction (p<0.05). The subscapularis tendon was significantly more likely to be abnormal if the supraspinatus was retracted than if no retraction was present (p<0.05). There were no significant differences in coraco-humeral distances between the groups. CONCLUSION: Subscapularis tendon signal and structural changes are frequently associated with full-thickness supraspinatus tendon tears, particularly if the supraspinatus is significantly retracted. In this static MRI series, the data do not support the occurrence of classical subcoracoid impingement as an aetiology; however, they may support the possibility of a dynamic mechanism, to which future studies could be directed.

A comparison of whole-body MRI and CT for the staging of lymphoma.

OBJECTIVE: Our objective was to compare whole-body MRI and CT for the staging of lymphoma. CONCLUSION: Whole-body MRI represents an alternative to CT in the staging of lymphoma, with an ability to stage disease, identify lymph nodes greater than 1.2 cm, and the additional ability to evaluate for the presence or absence of disease spread to bone marrow. CT allows detection of more nodes (< 1.2 cm) than MRI but this does not alter tumor stage.

Skeletal muscle metastasis from uterine leiomyosarcoma.

A case of a 68-year-old woman who presented with a rapidly enlarging painful right thigh mass is presented. She had a known diagnosis of uterine leiomyosarcoma following a hysterectomy for dysfunctional uterine bleeding. She subsequently developed a single hepatic metastatic deposit that responded well to radiofrequency ablation. Whole-body MRI and MRA revealed a vascular mass in the sartorius muscle and a smaller adjacent mass in the gracilis muscle, proven to represent metastatic leiomyosarcoma of uterine origin. To our knowledge, metastatic uterine leiomyosarcoma to the skeletal muscle has not been described previously in the English medical literature.

Osteosarcoma arising in a femur with melorheostosis and osteopathia striata.

Osteopathia striata is an asymptomatic autosomal dominant or sporadically inherited disorder that causes dense striations at sites of endochondral bone formation, with a predilection for the metaphyses of long bones. Melorheostosis is a mixed sclerosing dysplasia with disturbance of both endochondral and intramembranous ossification, in which disordered intramembranous ossification dominates. It presents typical radiological changes of cortical hyperostosis distributed along a sclerotome with variable associated cutaneous and clinical features. Overlap syndromes including one or more of these diseases are described. We report a 44-year-old man with both melorheostosis and osteopathia striata who presented with pain secondary to superimposed osteosarcoma. In reporting this case we discuss the relationship between sclerosing dysplasia and either coexisting or complicating sarcoma.

Trends in CT colonography.

CT colonography (virtual colonoscopy) is a safe, noninvasive method of examining the large bowel. Since its first description in 1994, the technique has undergone rapid development, stimulating considerable interest in its potential as both a diagnostic and screening tool. Diagnostic performance statistics have been encouraging, with predictive values rivaling those of barium enema and approaching those of endoscopic colonoscopy. Improvements are underway in methods of bowel preparation, scanning procedure, and image display. Increasing experience with the technique is reflected in better understanding and characterization of both two-dimensional and three-dimensional findings, resulting in improved study performance and interpretation. This review attempts to chart the development of CT colonography, with an emphasis on published results and current research interests. We propose potential directions for future study and means toward effective implementation of CT colonography in clinical practice.

In-line fiber étalon for strain measurement.

A description and demonstration of a fiber interferometer that uses a short segment of silica hollow-core fiber spliced between two sections of single-mode fiber to form a mechanically robust in-line cavity are presented. The hollow-core fiber is specifically manufactured to have an outer diameter that is equal to the outer diameter of the single-mode lead fibers, thereby combining the best qualities of existing intrinsic and extrinsic Fabry-Perot sensors. A dynamic strain resolution of ~22 nepsilon/ radicalHz at frequencies of >5 Hz with a sensor gauge length of 137 microm is demonstrated.