Running is a popular activity practiced worldwide. It is important to understand how running affects joint health to provide recommendations to sports medicine practitioners and runners. Our aim was to summarize the influence of running on lower limb cartilage morphology and composition using quantitative magnetic resonance imaging (MRI). Prospective repeated-measures studies evaluating cartilage using MRI before and after running were included. Data sources included Pubmed, Embase, CINAHL, SportDiscus, Web of Science, and Cochrane Central Registry of Controlled Trials. Qualitative analyses considered the number and methodological quality ratings of studies based on the QualSyst tool, and recommendations were based on the strength of evidence (strong, moderate, limited, or very limited). Quantitative analysis involved meta-analyses, for which effect sizes were calculated as Hedge’s g standardized mean differences. We included 43 articles, assessing seven outcomes (lesions, volume, thickness, glycosaminoglycan content, and T1ρ, T2, and T2* relaxation times). Nineteen articles were rated as high quality, 24 were rated as moderate quality, and none were rated as low quality. Qualitative analyses suggest that running may cause an immediate reduction in knee cartilage volume, thickness, as well as T1ρ and T2 relaxation times immediately; however, these changes did not persist. Meta-analyses revealed a small and moderate decrease immediately following a single running bout in T2 relaxation time in the medial femur and tibia, respectively. Qualitative analyses indicated that the influence of repeated exposure to running on cartilage morphology and composition was limited. Despite conflicting evidence regarding pre-existing knee cartilage lesions, moderate evidence suggests that running does not lead to the formation of new lesions. Repeated running exposure did not cause changes to foot and ankle cartilage thickness or composition. Changes to lower limb cartilage following running are transient. Immediate changes to cartilage morphology and composition, which likely reflect natural fluid dynamics, do not persist and were generally not significant when pooled statistically. Results suggest that cartilage recovers well from a single running bout and adapts to repeated exposure. Given that moderate evidence indicates that running does not lead to new lesions, future trials should focus on clinical populations, such as those with osteoarthritis. Not applicable.

The Influence of Running on Lower Limb Cartilage: A Systematic Review and Meta-analysis.

Is running good or bad for your knees? A systematic review and meta-analysis of cartilage morphology and composition changes in the tibiofemoral and patellofemoral joints.

Can We Afford to Ignore the Biology of Joint Healing and Graft Incorporation After ACL Reconstruction

ObjectiveWe evaluated a fully automated femoral cartilage segmentation model for measuring T2 relaxation values and longitudinal changes using multi-echo spin-echo (MESE) magnetic resonance imaging...

Open Source Software for Automatic Subregional Assessment of Knee Cartilage Degradation Using Quantitative T2 Relaxometry and Deep Learning.

Deep learning (DL)‐based automatic segmentation models can expedite manual segmentation yet require resource‐intensive fine‐tuning before deployment on new datasets. The generalizability of DL methods to new datasets without fine‐tuning is not well characterized.

Generalizability of Deep Learning Segmentation Algorithms for Automated Assessment of Cartilage Morphology and MRI Relaxometry

Characterizing the transient response of knee cartilage to running: Decreases in cartilage T2 of female recreational runners

Non-ionic CT contrast solutions rapidly alter bovine cartilage and meniscus mechanics.

ObjectiveTo evaluate effects of a common CT contrast agent (iohexol) on the mechanical behaviors of cartilage and meniscus. MethodsIndentation responses of juvenile bovine cartilage and meniscus were monitored following exposure to undiluted contrast agent (100% CA), 50% CA/water, 50% CA/Phosphate Buffered Saline (PBS) or PBS alone, and during re-equilibration in PBS. The normalized peak force [Formula], effective osmotic strain ({varepsilon}osm), and normalized effective contact modulus [Formula] were calculated for every cycle, with time constants determined for both exposure and recovery via mono- or biexponential fits to [Formula]. ResultsAll cartilage CA groups exhibited long-term increases in [Formula] following exposure, although the hyperosmolal 100% CA and 50% CA/PBS groups showed an initial transient decrease. Meniscus presented opposing trends, with decreasing [Formula] for all CA groups. Re-equilibration in PBS for 1hr after exposure to 100% CA did not produce recovery to baseline [Formula] in either tissue. The recovery time for meniscus was substantially longer than that of cartilage. [Formula] increased with CA exposure time for cartilage but decreased for meniscus, suggesting an increased effective stiffness for cartilage and decreased stiffness for meniscus. Long-term changes to{varepsilon} osm in both tissues were consistent with changes in [Formula]. ConclusionExposure to iohexol solutions affected joint tissues differentially, with increased cartilage stiffness, likely relating to competing hyperosmotic and hypotonic interactions with tissue fixed charges, and decreased meniscus stiffness, likely dominated by hyperosmolarity. These altered tissue mechanics could allow non-physiological deformation during ambulatory weight-bearing, resulting in an increased risk of tissue or cell damage.

https://www.biorxiv.org/content/biorxiv/early/2019/12/13/2019.12.13.874743.full.pdf

Hollis A. Crowder

Papers

Characterizing the transient response of knee cartilage to running: Decreases in cartilage T2 of female recreational runners

Generalizability of Deep Learning Segmentation Algorithms for Automated Assessment of Cartilage Morphology and MRI Relaxometry

Non-ionic CT contrast solutions rapidly alter bovine cartilage and meniscus mechanics.

Non-ionic CT Contrast Solutions Rapidly Alter Bovine Cartilage and Meniscus Mechanics