Title: Isolated meniscal root tear and its relationship with medial tibiofemoral cartilage damage and meniscal hypertrophy. the most study
Abstract: Purpose: The meniscal root is a ligamentous structure that anchors the posterior horn of the meniscus to the tibial plateau. Association of isolated meniscal root tears with progression of OA or cartilage loss has not been examined. Aim was to assess the cross sectional association of medial meniscal root tears with prevalent medial tibiofemoral (TF) cartilage damage, medial meniscal extrusion and meniscal hypertrophy in subjects with radiographic OA. We also assessed if isolated medial meniscal root tears increased the risk of incident/progressive cartilage damage in the medial TF compartment at 30-month follow up. Methods: Of 6052 knees from 3026 subjects of the Multicenter Osteoarthritis Study, 1855 knees had whole knee radiographic OA at baseline and were eligible for progression of radiographic OA. Of these, 597 knees were randomly selected for this study. 49 knees were excluded because baseline scores for meniscal root tear and cartilage were unavailable or because cartilage could not be scored at follow-up. Age, gender, BMI, alignment of the knee and Kellgren Lawrence grades were recorded. Cartilage damage was semiquantitatively scored using WORMS in the 5 subregions of the medial and lateral TF compartments, and was defined to be WORMS score ≥2. Longitudinal progression of cartilage damage was definied as WORMS score increase from baseline to follow-up including intra-grade changes in at least one subregion. Meniscal morphology was scored from 0-4 according to WORMS. Meniscal extrusion and intrasubstance signal changes were recorded as present or absent. "Isolated meniscal root tear" was defined as the presence of a root tear without any additional meniscal pathology (WORMS 1-4). Medial meniscal hypertrophy was defined as the presence of an increase in meniscal height by >2mm of the meniscal body relative to that of the lateral meniscus on the same coronal image where meniscal extrusion was scored. We studied 3 groups of knees: 1. knees with an isolated medial meniscal root tear (the exposed group); 2. knees without root tears but with meniscal WORMS scores 1-4 pointing to other meniscal pathology (referent group A); and 3. those without root tear or meniscal pathology (referent group B). In the longitudinal analysis, we calculated relative risks (RR) of incident/progressing cartilage damage comparing the exposed group and the referent group A to the referent group and B, adjusting for age, gender, BMI, and malalignment. Results: For cross-sectional analyses 594 knees (1 knee/subject) were included (64.1% women, mean age 62.8 +/- 7.9, mean BMI 30.9 +/-5.2¬¬). At baseline 62.7% had meniscal extrusion and 11.9% showed meniscal hypertrophy (Table 1). There were 37 knees in the exposed group, 294 in the referent group A and 264 in group B. Exposed knees showed higher prevalence of meniscal extrusion than referent group B (91.9% vs. 60.7%, p<0.0001, Table 1). Prevalence of meniscal hypertrophy was higher in the exposed group (89.2%) than either referent groups (A: 8.8%, p<0.0001: B: 4.6%, p<0.0001). Prevalence of cartilage damage in at least one of medial compartment subregions was higher in the exposed group (97.3%) than in group B (63.7%, p<0.0001) but not A (95.2%, p=0.057). Longitudinal analyses included 548 knees. There were 33 knees in the exposed group, 270 in referent group A and 245 in group B. Using group B as the reference, adjusted RR of cartilage loss was 2.04 (95%CI 1.19 - 3.49) for the exposed group and 1.84 (1.32 - 2.58) for group A. Conclusions: Isolated medial meniscal root tears are strongly associated with medial meniscal extrusion and hypertrophy. Isolated meniscal root tears and other meniscal tears or maceration seem to have similar adverse effects on cartilage integrity longitudinally.Table 1Prevalence of meniscal extrusion, hypertrophy and cartilage damage at baselineOverall N(%)Exposed GroupReferent Group (A)P values Difference with the Exposed GroupReferent Group (B)P values Difference with the Exposed GroupMeniscal extrusion365 (62.7)34 (91.9)221 (78.9)0.062109 (41.3)<.0001Meniscal hypertrophy71 (11.9)33 (89.2)26 (8.8)<.0001*12 (4.6)<.0001Cartilage damage483 (81.3)36 (97.3)279 (95.2)0.57168 (63.6)<.0001* Statistically significant. Open table in a new tab Table 2Relative risk of incident/progressing tibiofemoral cartilageIncident or progressing femoral or tibial cartilage damageNo. of kneesn (%)Crude RRAdj RRIsolated Medial meniscal root tear (exposed group)3319 (57.6)2.35* (1.4,3.94)2.04* (1.19,3.49)No root tear, but with any meniscal pathology in posterior horn and/or body (group A)270139 (51.5)2.10* (1.55,2.85)1.84* (1.32,2.58)No root tear, without meniscal pathology (group B)24560 (24.5)1.00 (ref)1.00 (ref)* Statistically significant. Open table in a new tab * Statistically significant. * Statistically significant.