Development and preliminary validation of a meniscal symptom index

Abstract

Objective: In diagnosing symptomatic meniscal tear, clinicians often query patients with a "checklist" of symptoms such as "popping" or "catching." There has been little research on the reliability or diagnostic value of these terms.

Methods: We developed questions to elicit the presence of 11 checklist symptoms associated with meniscal tear and administered a survey with both "checklist" and expanded descriptions to study subjects. We examined the reliability of the checklist and expanded versions of each item. Validity was evaluated in relation to the clinical diagnosis of symptomatic meniscal tear, which consisted of the clinical impression of the treating orthopedic surgeon based upon physical examination, history, and magnetic resonance imaging. We developed a Meniscal Symptom Index, calculated as the sum of those expanded descriptive items that were independently associated with symptomatic meniscal tear in multivariate logistic regression.

Results: A total of 300 individuals (mean±SD age 52±12 years, 67% women) completed the survey. One hundred twenty-one had symptomatic meniscal tear. Test-retest reliability was higher for expanded descriptions than for checklist items. The Meniscal Symptom Index consisted of 4 expanded items: localized pain, clicking, catching, and giving way. Among the subjects with none of these symptoms, 16% (95% confidence interval [95% CI] 2%, 30%) had symptomatic meniscal tear, whereas among those with all 4 symptoms, 76% (95% CI 63%, 88%) had symptomatic meniscal tear (P for trend = 0.0001).

Conclusion: Clinicians should use expanded symptom definitions when querying patients about meniscal symptoms. A newly developed Meniscal Symptom Index holds promise as a diagnostic tool and merits further validation.

Figure 1. Probability of having symptomatic meniscal tear given number of symptoms endorsed in meniscal symptom index

The bars show the percent of patients with symptomatic meniscal tear, stratified by the number of symptoms endorsed in the meniscal symptom index. This index is comprised of the following four symptoms, expressed as expanded descriptions: clicking (Do you feel a clicking sensation or hear a clicking noise when you move your knee?), catching (Do you feel that sometimes something is caught in your knee that momentarily prevents movement?), giving way (Do you sometimes feel that your knee will give out and not support your weight?) and localized pain (Is your knee pain centered to 1 spot on the knee that you can point to with your finger?). Endorsed items are added, without weighting, to yield an index with possible range from 0 to 4. The error bars represent the 95% confidence intervals. *symptoms included: clicking, catching, giving way and localized pain