M. van Holsbeeck

Rotator-cuff changes in asymptomatic adults. The effect of age, hand dominance and gender

We studied the integrity of the rotator cuff in both dominant and non-dominant shoulders of 90 asymptomatic adults between the ages of 30 and 99 years using ultrasound. The criteria for diagnosis had been validated on unembalmed cadaver specimens. We found no statistically significant difference in the incidence of impingement findings between dominant and non-dominant arms or between genders. The prevalence of partial- or full-thickness tears increased markedly after 50 years of age: these were present in over 50% of dominant shoulders in the seventh decade and in 80% of subjects over 80 years of age. Our results indicate that rotator-cuff lesions are a natural correlate of ageing, and are often present with no clinical symptoms. Treatment should be based on clinical findings and not on the results of imaging.

ShearWave elastography: repeatability for measurement of tendon stiffness.

Tendon injuries are common and a significant source of pain and disability. Tendon injuries are often treated with a variety of non-surgical (e.g., physical therapy) and surgical interventions, along with a reduction of normal physical activities as the tendon heals [1–3]. However, it is difficult to objectively determine when the tendon has healed sufficiently and has the functional capacity to return to normal activities. Previous research has documented the functional capacity of tendons by measuring their stiffness under in vitro [4, 5] and in vivo [6, 7] conditions, but the technologies used for measuring tendon stiffness are applicable only to in vitro conditions (e.g., mechanical testing systems) or require the highly invasive implantation of sensors (e.g., strain gauges) under in vivo conditions. Conventional imaging modalities (e.g., ultrasound, MRI) can monitor changes in the appearance of tendons over time, but these imaging modalities do not provide an objective, quantitative assessment of tendon healing. A technique that could reliably provide a non-invasive quantitative assessment of tendon mechanical properties in vivo would have significant clinical application as a tool for monitoring tendon changes as a result of injury, pathology, and/or treatment. Shear-wave elastography is a relatively new technology that has the potential to assess the functional capacity of healing tendons in vivo. This technique applies an acoustic radiation force via an ultrasonic beam to the tissue(s), and then utilizes an ultrafast (up to 20 kHz) imaging sequence to measure the speed of the shear waves that result from this applied force. Shear-wave propagation increases as tissue stiffness increases, thus allowing for the indirect estimation of tissue stiffness from shear-wave speed. This technology has been used primarily as a diagnostic tool to identify fibrous masses in breast tissue [8] and has also been applied to the liver, arteries, and muscle [9–12], but its use in tendon is relatively new. Shear-wave elastography has been shown to have good reproducibility in breast imaging [8], but the repeatability for assessing tendon stiffness is not known. Therefore, the objective of this study was to determine the in vitro and in vivo repeatability of shear-wave elastography for estimating tendon stiffness. We hypothesized that in vitro repeatability would be better than in vivo repeatability, and that repeatability would be no worse than “moderate” (i.e., ICC≥0.41) under both in vitro and in vivo conditions.

Radiographic findings of spontaneous subluxation of the sternoclavicular joint

SummaryEight middle-aged women with spontaneous atraumatic subluxation of the sternoclavicular joint were evaluated with radiography and computed tomography. All patients were employed in occupations involving moderate to heavy physical labour, and no patients could recall a specific traumatic incident associated with onset of symptoms. In seven of the eight patients, the displacement of the medial clavicle was in a cranial direction; in four of the eight patients, there was an associated anterior subluxation, and in one patient, the subluxation was purely anterior. All five patients with an anterior component to the sternoclavicular subluxation had associated condensing osteitis of the clavicle. The sclerosis of the medial clavicle is possibly the result of chronic abrasion on the sternum and first costal cartilage in association with normal respiration and with upper extremity motion.

Ultrasound of Soft Tissue Tumors

This chapter illustrates how ultrasound is currently used in imaging soft tissue tumors and detail the advantages and drawbacks of this modality The use of ultrasound-guided aspiration or core biopsy is emphasized, and new applications that are being developed in the field of dermatology are described. The ultrasound appearance of the most common, benign soft tissue tumors reported is briefly discussed and documented.

Sonographic Examination of the Musculoskeletal System

Two decades ago ultrasound was first applied to the evaluation of disorders of the musculoskeletal system [1]. This was limited to the diagnosis of popliteal cysts (Baker’s cysts), which took advantage of ultrasound’s inherent ability to easily demonstrate fluid collections. Later, ultrasound was applied to the evaluation of tendon pathology. However, limitations in image quality imposed by equipment available at that time reduced sensitivity and specificity of the technique. In the past few years we have seen tremendous advances in sonographic image quality based largely on improved high frequency transducer technology. This has greatly broadened the spectrum of sonographic applications in the diagnosis of musculoskeletal disorders, as well as allowing increased diagnostic accuracy in areas already established [2].