A clinical prediction rule for meniscal tears in primary care: development and internal validation using a multicentre study

Abstract

BackgroundIn primary care, meniscal tears are difficult to detect. A quick and easy clinical prediction rule based on patient history and a single meniscal test may help physicians to identify high-risk patients for referral for magnetic resonance imaging (MRI). AimThe study objective was to develop and internally validate a clinical prediction rule (CPR) for the detection of meniscal tears in primary care. Design and settingIn a cross-sectional multicentre study, 121 participants from primary care were included if they were aged 18-65 years with knee complaints that existed for <6 months, and who were suspected to suffer from a meniscal tear. MethodOne diagnostic physical meniscal test and 14 clinical variables were considered to be predictors of MRI outcome. Using known predictors for the presence of meniscal tears, a 'quick and easy' CPR was derived. ResultsThe final CPR included the variables sex, age, weight-bearing during trauma, performing sports, effusion, warmth, discolouration, and Deep Squat test. The final model had an AUC of 0.76 (95% CI = 0.72 to 0.80). A cut-point of 150 points yielded an overall sensitivity of 86.1% and a specificity of 45.5%. For this cutpoint, the positive predictive value was 55.0%, and the negative predictive value was 81.1%. A scoring system was provided including the corresponding predicted probabilities for a meniscal tear. ConclusionThe CPR improved the detection of meniscal tears in primary care. Further evaluation of the CPR in new primary care patients is needed, however, to assess its usefulness.

Diagnostic Validity of Combining History Elements and Physical Examination Tests for Traumatic and Degenerative Symptomatic Meniscal Tears

“…More than 60% of all SMT cases in our cohort reported having no mechanical symptoms as reported on individual questions from the KOOS questionnaire. This result is comparable with other cohorts with meniscal tears [3,5,21,22,51]. Also, mechanical symptoms, when present, do not arise exclusively from meniscal tears and may be positive in other disorders such as ACL tear or osteoarthritis [3,6].…”

“…The clusters correctly classified 58% and 65% of all cases and noncases (see 2 × 2 tables in Appendix 3). Although this can be expected from clustering and combination analyses [3,22,23], it may also be explained by the heterogeneous presentation of degenerative SMT, which often overlaps with knee osteoarthritis [51], as it was likely the case in our cohort; 40% participants had combined diagnoses of SMT and osteoarthritis [3].…”

“…Also, mechanical symptoms, when present, do not arise exclusively from meniscal tears and may be positive in other disorders such as ACL tear or osteoarthritis [3,6]. This adds to the growing evidence suggesting that these history elements and tests may have limited diagnostic value, as well as a possibly limited use as a surgical criterion [3,10,16,18‐20,22,23,49,52‐55].…”

“…Diagnostic reasoning combines multiple patients' history elements with physical examination tests to make a valid diagnosis of SMT. Only a few studies have assessed the validity of combining history elements and physical examination tests [3,21‐23]. Although these studies present encouraging results regarding the combination of various history elements and tests, there are significant limitations [24], notably the presence of spectrum bias [23], use of MRI only as a reference standard [21,22], as well as ultimately providing rules that may lack ease‐of‐use for clinicians [25,26].…”

“…Only a few studies have assessed the validity of combining history elements and physical examination tests [3,21‐23]. Although these studies present encouraging results regarding the combination of various history elements and tests, there are significant limitations [24], notably the presence of spectrum bias [23], use of MRI only as a reference standard [21,22], as well as ultimately providing rules that may lack ease‐of‐use for clinicians [25,26]. Therefore, to improve current evidence on the clinical diagnosis of SMT, our objective was to assess the validity of diagnostic clusters combining history elements and physical examination tests to diagnose or exclude traumatic or degenerative SMT compared with other common knee disorders.…”