Assessing the effect of football play on knee articular cartilage using delayed gadolinium-enhanced MRI of cartilage (dGEMRIC)

Advanced MRI Approaches for Evaluating Common Lower Extremity Injuries in Basketball Players: Current and Emerging Techniques

Magnetic resonance imaging (MRI) can provide accurate and non-invasive diagnoses of lower extremity injuries in athletes. Sport-related injuries commonly occur in and around the knee and can affect the articular cartilage, patellar tendon, hamstring muscles, and bone. Sports medicine physicians utilize MRI to evaluate and diagnose injury, track recovery, estimate return to sport timelines, and assess the risk of recurrent injury. This article reviews the current literature and describes novel developments of quantitative MRI tools that can further advance our understanding of sports injury diagnosis, prevention, and treatment while minimizing injury risk and rehabilitation time. Innovative approaches for enhancing the early diagnosis and treatment of musculoskeletal injuries in basketball players span a spectrum of techniques. These encompass the utilization of T2, T1ρ, and T2* quantitative MRI, along with dGEMRIC and Na-MRI to assess articular cartilage injuries, 3D-Ultrashort echo time MRI for patellar tendon injuries, diffusion tensor imaging for acute myotendinous injuries, and sagittal short tau inversion recovery and axial long-axis T1-weighted, and 3D Cube sequences for bone stress imaging. Future studies should further refine and validate these MR-based quantitative techniques while exploring the lifelong cumulative impact of basketball on players' knees. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 2.

Enzymatically Cross-Linked Silk Fibroin-Based Hierarchical Scaffolds for Osteochondral Regeneration

Osteochondral (OC) regeneration faces several limitations in orthopedic surgery, owing to the complexity of the OC tissue that simultaneously entails the restoration of articular cartilage and subchondral bone diseases. In this study, novel biofunctional hierarchical scaffolds composed of a horseradish peroxidase (HRP)-cross-linked silk fibroin (SF) cartilage-like layer (HRP-SF layer) fully integrated into a HRP-SF/ZnSr-doped β-tricalcium phosphate (β-TCP) subchondral bone-like layer (HRP-SF/dTCP layer) were proposed as a promising strategy for OC tissue regeneration. For comparative purposes, a similar bilayered structure produced with no ion incorporation (HRP-SF/TCP layer) was used. A homogeneous porosity distribution was achieved throughout the scaffolds, as shown by micro-computed tomography analysis. The ion-doped bilayered scaffolds presented a wet compressive modulus (226.56 ± 60.34 kPa) and dynamic mechanical properties (ranging from 403.56 ± 111.62 to 593.56 ± 206.90 kPa) superior to that of the control bilayered scaffolds (189.18 ± 90.80 kPa and ranging from 262.72 ± 59.92 to 347.68 ± 93.37 kPa, respectively). Apatite crystal formation, after immersion in simulated body fluid (SBF), was observed in the subchondral bone-like layers for the scaffolds incorporating TCP powders. Human osteoblasts (hOBs) and human articular chondrocytes (hACs) were co-cultured onto the bilayered structures and monocultured in the respective cartilage and subchondral bone half of the partitioned scaffolds. Both cell types showed good adhesion and proliferation in the scaffold compartments, as well as adequate integration of the interface regions. Osteoblasts produced a mineralized extracellular matrix (ECM) in the subchondral bone-like layers, and chondrocytes showed GAG deposition. The gene expression profile was different in the distinct zones of the bilayered constructs, and the intermediate regions showed pre-hypertrophic chondrocyte gene expression, especially on the BdTCP constructs. Immunofluorescence analysis supported these observations. This study showed that the proposed bilayered scaffolds allowed a specific stimulation of the chondrogenic and osteogenic cells in the co-culture system together with the formation of an osteochondral-like tissue interface. Hence, the structural adaptability, suitable mechanical properties, and biological performance of the hierarchical scaffolds make these constructs a desired strategy for OC defect regeneration.

Prevalence of knee osteoarthritis features on magnetic resonance imaging in asymptomatic uninjured adults: a systematic review and meta-analysis

Background

Knee MRI is increasingly used to inform clinical management. Features associated with osteoarthritis are often present in asymptomatic uninjured knees; however, the estimated prevalence varies substantially between studies. We performed a systematic review with meta-analysis to provide summary estimates of the prevalence of MRI features of osteoarthritis in asymptomatic uninjured knees.

Methods

We searched six electronic databases for studies reporting MRI osteoarthritis feature prevalence (ie, cartilage defects, meniscal tears, bone marrow lesions and osteophytes) in asymptomatic uninjured knees. Summary estimates were calculated using random-effects meta-analysis (and stratified by mean age: <40 vs ≥40 years). Meta-regression explored heterogeneity.

Results

We included 63 studies (5397 knees of 4751 adults). The overall pooled prevalence of cartilage defects was 24% (95% CI 15% to 34%) and meniscal tears was 10% (7% to 13%), with significantly higher prevalence with age: cartilage defect <40 years 11% (6%to 17%) and ≥40 years 43% (29% to 57%); meniscal tear <40 years 4% (2% to 7%) and ≥40 years 19% (13% to 26%). The overall pooled estimate of bone marrow lesions and osteophytes was 18% (12% to 24%) and 25% (14% to 38%), respectively, with prevalence of osteophytes (but not bone marrow lesions) increasing with age. Significant associations were found between prevalence estimates and MRI sequences used, physical activity, radiographic osteoarthritis and risk of bias.

Conclusions

Summary estimates of MRI osteoarthritis feature prevalence among asymptomatic uninjured knees were 4%–14% in adults aged <40 years to 19%–43% in adults ≥40 years. These imaging findings should be interpreted in the context of clinical presentations and considered in clinical decision-making.