Magnetic resonance imaging of meniscal degeneration in asymptomatic knees

Abstract

Histopathological studies have suggested that spontaneous degeneration of knee menisci predisposes to symptomatic tears. We used magnetic resonance (MR) imaging to study noninvasively 20 patients with documented meniscal tears in one knee but asymptomatic contralateral knees, 18 normal controls, and 15 patients with symptomatic nonmeniscal knee disorders. A scoring system for MR signal changes was developed, and differences between the three groups were tested for significance by a multivariate analysis of covariance. MR signal changes in the menisci begin at around 30 years of age, progress with age, occur in both men and women, and occur in subjects who are inactive as well as those who undergo habitual knee stress exercises. Most subjects with documented meniscal tears in one knee have MR signals in the asymptomatic contralateral knee that reflect a more advanced degree of meniscal degeneration than in age-comparable normal controls or patients with nonmeniscal knee disorders. After adjustment for potential confounding variables, weight, and sex, the mean scores in the asymptomatic knee of patients with meniscal disease are significantly higher than those of normal controls (p = 0.021) and nonmeniscal disease patients (p = 0.019). These results document the occurrence of age-dependent degeneration within knee menisci, and support the hypothesis that a segment of the population has pre-existing meniscal degeneration predisposing them to traumatic or spontaneous meniscal tears.

Silent meniscal abnormalities in athletes: magnetic resonance imaging of asymptomatic competitive gymnasts.

“…They all completed a questionnaire confirming no prior history of meniscal injury or surgery, and a full clinical examination of the knee was performed by a sports medicine physician (DOH). The experimental group comprised 14 asymptomatic gymnasts (four female, 10 male) with an average age of 20 (range [18][19][20][21][22], and an average period of gymnastics training of 13 years (range [8][9][10][11][12][13][14][15][16][17][18][19][20].Three subjects had a history of injury in one knee-a past meniscal injury, previous arthrography, and a history of patella tendinitis and chondromalacia patella-and in these subjects only the single asymptomatic knee was examined. In one asymptomatic subject, only a single knee was scanned.…”

The role of magnetic resonance imaging in routine decision making for meniscal surgery

“…Considering the long delay in surgical intervention for four patients having false-negative MRI results, one could suppose that the preexisting degenerative changes seen in the MRI were a predisposition to the development of a degenerative meniscal tear. A similar situation was also described by Negendank et al [10]. On the other hand, the tear in the patient with a "false-positive" MRI result may have already healed [19].…”

“…Aside from the MRI results, this was the only significant difference which was found between the two groups. Since increased signal intensity occurs in most menisci as a part of the aging process, and the incidence rises with age, one must be careful in interpreting MRI slices in older patients [5,10]. In the present study 60% of patients did not undergo operative treatment, due to vanishing of the clinical symptoms, and 18% of these showed grade III or IV signal alterations on MRI.…”

SENSITIVITY OF LOW‐FIELD T2* IMAGES FOR DETECTING THE PRESENCE AND SEVERITY OF HISTOPATHOLOGIC MENISCAL LESIONS IN DOGS

“…The gradient‐echo T2 * sequences provided good quality images of the menisci 10 . Factors limiting clinical application of previously published MR imaging findings from cruciate‐deficient dogs include the wide variation in scanners, technical protocols, and grading criteria 7,9,10,12,15 . We attempted to reduce some of this variation by using a modification of a previously described imaging protocol and grading system.…”

“…Arthrotomy and arthroscopy are used commonly for intraarticular stifle evaluation, however intra meniscal lesions cannot be detected with either procedure. In human patients with unilateral meniscal tears, meniscal lesions have been identified in the contralateral asymptomatic knee using magnetic resonance (MR) imaging, suggesting that meniscal degeneration predisposes to tears 7 . Histopathologic changes have also been found in grossly normal menisci in dogs with cranial cruciate ligament rupture 8 .…”