Meniscus sizing using three-dimensional models of the ipsilateral tibia plateau based on CT scans - an experimental study of a new sizing approach

Meniscal allograft transplantation: A matched-pair analysis reveals worse sport activity level but similar clinical improvement and survival in women compared to men

PURPOSE

The aim of this study was to assess how gender might affect the clinical outcome and survival of meniscal allograft transplantation (MAT).

METHODS

A total of 358 patients (23.2% women, 76.8% men) were treated with fresh-frozen nonirradiated allografts implantated arthroscopically using a single- or double-tunnel technique without bone plugs and peripheral suture to the capsule with 'all-inside' stitches.

RESULTS

Patients were evaluated at baseline and 2-year follow-up with the Lysholm score, visual analogue scale (VAS) pain, the Knee Osteoarthritis Outcome Score (KOOS) subscales and Tegner score. Women presented higher body mass index (p < 0.0005), poorer baseline VAS (p = 0.012), Lysholm score (p = 0.005), KOOS symptom (p = 0.034) and KOOS pain (p = 0.030), Tegner score (preinjury and basal, p < 0.0001 and p = 0.002, respectively), a lower number of previous (p = 0.039) and concurrent (p = 0.001) anterior cruciate ligament reconstructions and a higher number of concurrent procedures (p = 0.032) and distal femoral osteotomies (p = 0.024). Worse results were documented in women at 2 years, with lower Lysholm score (p = 0.024) and Tegner score (p = 0.007) and a lower clinical survival rate (p = 0.03) (67.5% vs. 82.2%) in the overall patient cohort. However, the matched-pair analysis only confirmed a lower Tegner score value at 2 years (p = 0.016), while underlying the interplay of sex, age and concomitant cartilage lesions in determining the clinical outcome. The analysis of this large series of patients affected by postmeniscectomy syndrome and treated with MAT revealed gender differences.

CONCLUSION

While both genders benefited from a significant improvement, the female population presents more often with older age, concomitant cartilage lesions and a lower activity level, all factors contributing towards a lower clinical success after MAT.

LEVEL OF EVIDENCE

Level III, comparative study.

Could a three-dimensional contralateral meniscus segmentation for allograft or scaffold sizing be possible? A prospective study

PURPOSE

Meniscal allografts and biodegradable meniscal implants are attractive surgical options for painful subtotal or total meniscectomies. In order to get the best results, these should be as similar as possible to the original meniscus in terms of shape, structure, and volume. Three-dimensional meniscus sizing could be an approach to improve the accuracy of meniscus matching. Therefore, the aims of this study were to perform a comparative morphological and volumetric analysis of the healthy meniscus based on manual tri-planar segmentation and to demonstrate that the menisci from the contralateral knee could be used as a reference in the sizing of a meniscal graft or a scaffold.

METHODS

Three-dimensional meniscal models were created based on 120 MRIs in 60 healthy subjects (bilateral knees). The differences between the pairs of menisci concerning the widths, thicknesses, lateromedial distances, anteroposterior distances, angles of coverage, and meniscal volumes were evaluated. T-Student tests were used to compare the quantitative numerical variables of the different groups. Pearson's linear regression was used to determine if correlations existed between demographic variables (age, gender, height, weight) and anatomical parameters. Statistical significance was set at p < 0.05.

RESULTS

Comparing the 120 pairs of menisci of each subject, there was no statistically significant difference for all parameters studied for both the medial and lateral meniscus. When the measurements were stratified by gender, statistically significant differences were observed for all parameters except meniscal coverage angles. We observed that anteroposterior and lateromedial distances were positively correlated with height and body mass index both at the level of the medial meniscus (r = 0.68; r = 0.66; r = 0.65; and r = 0.63) and lateral (r = 0.68; r = 0.69; r = 0.61; and r = 0.60).

CONCLUSION

Our study demonstrated that the intra-individual 3D shapes of the left and right menisci are very similar. Therefore, the contralateral side could be used as a template for the 3D sizing of meniscal allografts or meniscal implants.

Osteochondral junction leakage and cartilage joint lubrication

BACKGROUND AND OBJECTIVES

Previous studies have shown that there is potentially interstitial fluid exchange between cartilage tissue and the subarticular spongiosa region in the case of injury or disease (e.g., osteoarthritis and osteoporosis). Interstitial flow is also required for cartilage lubrication under joint load. A key question then is how cartilage lubrication is modified by increased interstitial fluid leakage across the osteochondral junction. Thus, the purpose of this study is to develop a numerical model to investigate changes in cartilage lubrication with changes in osteochondral junction leakage.

METHODS

The multi-phase coupled model includes domains corresponding to the contact gap, cartilage tissue and subchondral bone plate region (ScBP). Each of these domains are treated as poroelastic systems, with their coupling implemented through mass and pressure continuity. The effects of osteochondral junction leakage on lubrication were investigated with a parametric study on the relative permeability between the ScBP and cartilage tissue.

RESULTS

Significant effects of ScBP permeability were predicted, especially during the early stage of the junction leakage development (early stage of the disease). There is a significant reduction in mixed-mode lubrication duration under the effect of increased junction leakage (the cartilage tissue mixed-mode lubrication duration is about 33% decrease for a relative permeability ratio of 0.1 between ScBP and cartilage tissue, and about 52% decrease under the osteoarthritis condition). In addition, the time for cartilage to reach steady-state consolidation is significantly reduced when ScBP permeability increases (the consolidation time reduces from roughly 2 h to 1.2 h when the relative permeability ratio increases from 0.001 to 0.1, and it reduces to 0.8 h for an advanced osteoarthritis condition). It is predicted that the initial friction coefficient could increase by over 60% when the ScBP permeability is consistent with an advanced osteoarthritis (OA) condition.

CONCLUSION

Increased osteochondral junction leakage induced by joint injury and disease could result in increased cartilage surface wear rates due to more rapid interstitial fluid depressurization within articular cartilage.