Knee joint biomechanics after meniscal tear and meniscectomy

Finite element analysis of the effect of meniscal tears and meniscectomies on human knee biomechanics.
Pena E, Calvo B, Martinez M, Palanca D, Doblare M. Clinical Biomechanics, 2005; 20, 498 – 507.

Previous post focused on the relationship between knee joint position sense and meniscal transplantation. There is a suggestion in the literature that knee proprioception is affected by meniscectomy or meniscal tears and meniscus transplantation seems to restore knee proprioceptive sensibility. This post is going to describe and analyze effect of meniscectomy and meniscal tear on knee joint biomechanics. 
Authors created 3D finite element model of the human knee joint after meniscal tear and partial meniscectomy to assess contact areas and pressure distribution between menisci and articular cartilage which could help to understand mechanisms of early cartilage degeneration following knee total or partial meniscectomy. Vertical compression force of 1150 N was applied to the knee joint in three conditions: healthy, meniscal tear, meniscectomy. Only static analyses were undertaken.  
In meniscal tear situation, study found that contact pressures and compression stresses increased by 50% to 150% depending on the structure and lesion type (meniscal tear, healthy meniscus, tibial/femoral cartilage; longitudinal, radial, oblique). Higher values were seen in totally meniscectomised joint, especially regarding articular cartilage (even up to 300% increase in compression stress). Authors noted appearance of new high contact stress in areas where it does not take place in healthy joint. They state that it may provoke instability and definitely alters knee kinematics. Similar knee behavior has been severally reported in case of ACL tear and following ACL reconstruction where articular cartilage was stressed in regions where is does not usually happens in a healthy joint. Moreover, longitudinal tear, where the amount of resectionized material is biggest, resulted in redistribution of the contact zones and stresses while opposite was seen in radial and oblique tears. In that case, contact pressure and compression stress significantly increased directly at lesion site.
Despite several limitations including possible error associated with this kind of measurement method, lack of comparison between different knee ranges of motion and lack of more accurate meniscus and cartilage models, this study proves the importance of such terms as preservation and meniscal repair for healthy knee joint biomechanics and for early OA prevention. 
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1 comment:

  1. Nice post. Meniscal tear is the most common knee injury. Thanks for sharing.

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