Change In Extrusion Research Articles

Concomitant Meniscotibial Ligament Reconstruction Decreases Meniscal Extrusion Following Medial Meniscus Allograft Transplantation: A Cadaveric Analysis

To compare meniscal extrusion (ME) following medial meniscus allograft transplantation (MMAT) with and without meniscotibial ligament reconstruction (MTLR). Ten cadaveric knees were size-matched with meniscus allografts. MMAT was performed via bridge-in-slot technique. Specimens were mounted in a testing system and ME was assessed via ultrasound anterior, directly over, and posterior to the medial collateral ligament at the joint line under 4 testing conditions: (1) 0° flexion and 0 newtons (N) of axial load, (2) 0° and 1,000 N, (3) 30° and 0 N, and (4) 30° and 1,000 N. For each condition, "mean total extrusion" was calculated by averaging measurements at each position. Next, MTLR was performed using 2 inside-out sutures through the remnant allograft meniscotibial ligament and secured to the tibia using anchors. The testing protocol was repeated. Differences in ME between MMAT alone versus MMAT+ MTLR were examined. Within-group differences between the measurement positions, loading states, and flexion angles also were assessed. "Mean total extrusion" was greater following MMAT alone (2.56 ± 1.23 mm) versus MMAT+ MTLR (2.14 ± 1.07 mm; P= .005) in the loaded state at 0° flexion. ME directly over the MCL was greater following MMAT alone (3.51 ± 1.00 mm) compared with MMAT+ MTLR (2.93 ± 0.79 mm; P= .054). Posteriorly, in the loaded state at 0°, ME was greater following MMAT alone (2.43 ± 1.10 mm) compared with MMAT+ MTLR (1.96 ± 0.99 mm; P= .010). In all conditions, ME was greater in the loaded state versus the unloaded state. Following MMAT, the addition of MTLR significantly reduced overall ME when compared with isolated MMAT during loading at 0° of flexion in a cadaveric model; given the small absolute values of change in extrusion, clinical significance cannot be gleaned from these findings. During medial meniscus allograft transplantation, augmentation with meniscotibial ligament reconstruction may limit meniscal extrusion and improve the biomechanical milieu of the knee joint following transplant.

Factors associated with longitudinal change of meniscal extrusion in overweight women without clinical signs of osteoarthritis.

To identify variables associated with longitudinal change in meniscal extrusion, which might be used as possible targets for knee osteoarthritis (KOA) prevention. In a high-risk population of middle-aged overweight women, meniscal extrusion was assessed with magnetic resonance imaging (1.5 T, coronal proton density, in-plane resolution 0.5mm2, Sante DICOM Editor) at baseline and after 30 months. Outcomes were the absolute change in medial and lateral extrusion (mm) and relative change in extrusion (%). Based upon literature, 11 factors were hypothesized to be associated with longitudinal change. Generalized estimating equations were used to model the effect on meniscal change (P<0.05). In total, 677 knees of 343 women were available for analysis, with a mean age of 55.7 years (+/-3.2) and a mean BMI of 32.3 kg/m2 (+/-4.2). The greatest change in meniscal extrusion appeared medially with incident meniscal tear (4.4%; absolute 0.9 mm (95% CI: 0.3, 1.5; P=0.004); relative 14.5% (4.4, 24.7; 0.005)). Varus malalignment was associated with an increase of medial extrusion of 0.6 mm (37.6%; 0.1, 1.0; 0.009). A 5 kg/m2 higher baseline BMI was associated with absolute and relative increase of medial extrusion of 0.2 mm and 2.96% (0.1, 0.3; <0.001 and 1.3, 4.8; 0.002). Less explicit but significant changes in extrusion appeared with longitudinal change in BMI. Meniscal tears, varus malalignment and BMI were significantly associated with change in meniscal extrusion in middle-aged overweight women, providing viable therapeutic targets to prevent or reduce extrusion and thereby decelerate KOA development.

Factors associated with longitudinal change of meniscal extrusion in overweight women without clinical signs of knee osteoarthritis

Purpose: Previously, we showed a significant and largely independent association between meniscal extrusion and incident knee osteoarthritis (KOA). With the present study, we aimed to identify variables associated with longitudinal change in meniscal extrusion, which might be used as possible targets for prevention of developing KOA. Methods: We used data from the PROOF trial, a preventive RCT which evaluated a high-risk population of 407 middle-aged overweight women (BMI ≥ 27 kg/m2). Meniscal extrusion was assessed on the mid-coronal slice of an MRI which were performed at baseline and after 30 months follow-up. Outcomes were the absolute change in meniscal extrusion (mm) or the absolute change in relative extrusion (%), evaluated for the medial as well as the lateral meniscus. Relative extrusion was calculated by dividing the meniscal extrusion by the width of the meniscus. Based upon literature, several factors were hypothesized to be associated with longitudinal change in meniscal extrusion, including baseline age, BMI, postmenopausal status, malalignment, quadriceps strength, physical activity, meniscal tears, having a past of knee injury and the presence of Heberden’s nodes and change in BMI over 30 months. Linear GEE models were used to model the effect of these covariates on the absolute change in extrusion. Separate models were used for the change in lateral and medial extrusion. An unstructured covariate matrix was used. Furthermore, models were made for the change in relative meniscal extrusion following the same procedure. Lastly, all these models were adjusted for tibial width, to take the difference in knee size into account. Results: For 343 subjects, sufficient MRI data were available for analysis. A 5 kg/m2increase in BMI resulted in an increase of medial extrusion of 0.16 mm (95% CI: 0.05, 0.26). The other factors included in the model were not significantly associated with a change in medial extrusion after 30 months. The model for lateral meniscal extrusion showed that an increase in BMI of 1 kg/m2in 30 months was associated with an increase of lateral meniscal extrusion of 0.07 mm (95% CI: 0.04, 0.11). None of the other factors included in the model influenced the change in lateral extrusion after 30 months. Adjusting for tibial width did not influence the results. The model for change in relative medial meniscal width only resulted in a significant increase of relative meniscal extrusion after 30 months of 2.9% (95 % CI: 1.15, 4.65) per 5 kg/m2. No other significant changes in relative medial extrusion were found. Relative lateral extrusion was increased by 0.57% (95% CI: 0.26, 0.88) with an increase in BMI of 1 kg/m2in 30 months. Adjusting for tibial width did not result in a change of significance. Conclusions: Baseline BMI and change of BMI over time were associated with change in meniscal extrusion of the medial and lateral meniscus, respectively. BMI therefore might be used as a target for reducing extrusion and by that decelerate the development of KOA. None of the other assessed variables showed significant results, which is quite remarkable given the findings of previous studies.

Longitudinal change in quantitative meniscus measurements in knee osteoarthritis--data from the Osteoarthritis Initiative.

We aimed to apply 3D MRI-based measurement technology to studying 2-year change in quantitative measurements of meniscus size and position. Forty-seven knees from the Osteoarthritis Initiative with medial radiographic joint space narrowing had baseline and 2-year follow-up MRIs. Quantitative measures were obtained from manual segmentation of the menisci and tibia using coronal DESSwe images. The standardized response mean (SRM = mean/SD change) was used as measure of sensitivity to longitudinal change. Medial tibial plateau coverage decreased from 34.8% to 29.9% (SRM -0.82; p < 0.001). Change in medial meniscus extrusion in a central image (SRM 0.18) and in the central five slices (SRM 0.22) did not reach significance, but change in extrusion across the entire meniscus (SRM 0.32; p = 0.03) and in the relative area of meniscus extrusion (SRM 0.56; p < 0.001) did. There was a reduction in medial meniscus volume (10%; p < 0.001), width (7%; p < 0.001), and height (2%; p = 0.08); meniscus substance loss was strongest in the posterior (SRM -0.51; p = 0.001) and weakest in the anterior horn (SRM -0.15; p = 0.31). This pilot study reports, for the first time, longitudinal change in quantitative 3D meniscus measurements in knee osteoarthritis. It provides evidence of improved sensitivity to change of 3D measurements compared with single slice analysis. • First longitudinal MRI-based measurements of change of meniscus position and size. • Quantitative longitudinal evaluation of meniscus change in knee osteoarthritis. • Improved sensitivity to change of 3D measurements compared with single slice analysis.