[Meniscus signals in vibration arthrography]

The technique of vibration arthrography (VAG) permits the non-invasive evaluation of internal derangements of the knee. Using the computer-assisted recording and analysis equipment which has previously been described, a major survey was conducted into the signal patterns present in subjects with symptomatic knee joints. Two hundred and forty-seven patients were examined, and all of these subsequently underwent arthroscopy. One hundred and seventy-two patients were demonstrated arthroscopically to have a meniscal lesion and 150 of these gave characteristic meniscal signals. This paper discusses the vibration signal patterns associated with the various types of meniscal tear and the effect of surgery on the meniscal signal. The overall accuracy of vibration arthrography in the diagnosis of meniscal pathology was 86%. In many cases, not only could the site of a meniscal tear be determined, but the type of tear could be diagnosed with reasonable accuracy.

Stress examination of traumatized lateral ligaments of the ankle

In the diagnostic analysis of acute injury to the lateral ankle ligaments, ankle arthrography and plain film stress examination play an important role. Inasmuch as the treatment of choice, whether conservative or surgery, and insofar as the therapeutic results may be determined by the extent of injury, it is important to have access to quantitative information on the functional properties of the involved ligaments at the time of the initial diagnostic studies. This can be obtained by measuring the strain on the anterior talofibular (tf) and calcaneofibular (cf) ligaments as a function of pressure applied to the distal tibia. Any device that ensures that the externally applied pressure is proportionally carried through to the ligaments can be used for this purpose. The results of 25 quantitative stress examinations using a Telos stress device are compared with arthrography findings and findings at surgery. Stress examination correlates well with both arthrographic and operative findings. The method is also useful for the evaluation of chronic ankle instability, follow-up examinations, and for the detection of vestiges of previous trauma of the contralateral ankle. The procedure is straightforward and noninvasive and can be performed within 15 minutes.