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Effect of Posterior Horn Medial Meniscus Root Tear on In Vivo Knee Kinematics.

Marsh CA, Martin DE, Harner CD, Tashman S - Orthop J Sports Med (2014)

Bottom Line: The affected knees of the subjects were then compared to their unaffected contralateral knees.Affected knees demonstrated significantly more lateral tibial translation than the uninjured contralateral limb in all dynamic activities.This study suggests that MMRT causes significant changes in in vivo knee kinematics and arthrokinematics and that the magnitude of these changes is influenced by dynamic task difficulty.

View Article: PubMed Central - PubMed

Affiliation: Biodynamics Laboratory, University of Pittsburgh, Pittsburgh, Pennsylvania, USA. ; Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.

ABSTRACT

Background: Medial meniscus root tear (MMRT) is a recently recognized yet frequently missed meniscal tear pattern that biomechanically creates an environment approaching meniscal deficiency.

Hypothesis/purpose: The purpose of this study was to assess the effect of MMRT on tibiofemoral kinematics and arthrokinematics during daily activities by comparing the injured knees of subjects with isolated MMRT to their uninjured contralateral knees. The hypothesis was that the injured knee will demonstrate significantly more lateral tibial translation and adduction than the uninjured knee, and that the medial compartment will exhibit significantly different arthrokinematics than the lateral compartment in the affected limb.

Study design: Cross-sectional study; Level of evidence, 3.

Methods: Seven subjects with isolated MMRT were recruited and volumetric, density-based 3-dimensional models of their distal femurs and proximal tibia were created from computed tomography scans. High-speed, biplane radiographs were obtained of both their affected and unaffected knees. Moving 3-dimensional models of tibiofemoral kinematics were calculated using model-based tracking to assess overall kinematic variables and specific measures of tibiofemoral joint contact. The affected knees of the subjects were then compared to their unaffected contralateral knees.

Results: Affected knees demonstrated significantly more lateral tibial translation than the uninjured contralateral limb in all dynamic activities. Additionally, the medial compartment displayed greater amounts of mobility than the lateral compartment in the injured limbs.

Conclusion: This study suggests that MMRT causes significant changes in in vivo knee kinematics and arthrokinematics and that the magnitude of these changes is influenced by dynamic task difficulty.

Clinical relevance: Medial meniscus root tears lead to significant changes in joint arthrokinematics, with increased lateral tibial translation and greater medial compartment excursion. With complete root tears, essentially 100% of circumferential fibers are lost. This study will further our knowledge of meniscal deficiency and osteoarthritis and provide a baseline for more common forms of medial meniscal injuries (vertical, horizontal, radial), with various degrees of circumferential fiber function remaining.

No MeSH data available.


Related in: MedlinePlus

Representative joint contact analysis from a single trial. The image shows affected and unaffected knees opened to compare joint contact patterns. Color maps demonstrate instantaneous joint space (bone-to-bone distances), while black dots demonstrate instantaneous location of joint contact (location of closest bone-to-bone distance), and white lines show the contact path throughout the chosen range of movement.
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fig4-2325967114541220: Representative joint contact analysis from a single trial. The image shows affected and unaffected knees opened to compare joint contact patterns. Color maps demonstrate instantaneous joint space (bone-to-bone distances), while black dots demonstrate instantaneous location of joint contact (location of closest bone-to-bone distance), and white lines show the contact path throughout the chosen range of movement.

Mentions: The segmented bone models were then matched to the x-ray images gathered during kinematic testing using a computerized, model-based tracking technique.7,8 Briefly, custom software created a virtual reconstruction of the testing environment, in which the segmented bone models were manually positioned via ray-traced projections of digitally reconstructed radiographs (DRRs). These manually placed DRRs were then used as an initial guess for the computer to automatically manipulate the bone to a position that maximized the correlations between the DRRs and actual radiographs from kinematic testing. This process was repeated for all frames in a trial. The location and orientation of the femur and tibia were then projected into 3D space, and their motions and positions relative to one another were calculated. Figure 4 shows the final product, with a representative joint contact analysis from a single-level walking trial. The performance of this system has been extensively validated, with precision in the order of 0.1 mm for in vitro testing8 and averaging 0.6 deg/0.5 mm for in vivo tibiofemoral kinematics during running.4


Effect of Posterior Horn Medial Meniscus Root Tear on In Vivo Knee Kinematics.

Marsh CA, Martin DE, Harner CD, Tashman S - Orthop J Sports Med (2014)

Representative joint contact analysis from a single trial. The image shows affected and unaffected knees opened to compare joint contact patterns. Color maps demonstrate instantaneous joint space (bone-to-bone distances), while black dots demonstrate instantaneous location of joint contact (location of closest bone-to-bone distance), and white lines show the contact path throughout the chosen range of movement.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2 - License 3
Show All Figures
getmorefigures.php?uid=PMC4588528&req=5

fig4-2325967114541220: Representative joint contact analysis from a single trial. The image shows affected and unaffected knees opened to compare joint contact patterns. Color maps demonstrate instantaneous joint space (bone-to-bone distances), while black dots demonstrate instantaneous location of joint contact (location of closest bone-to-bone distance), and white lines show the contact path throughout the chosen range of movement.
Mentions: The segmented bone models were then matched to the x-ray images gathered during kinematic testing using a computerized, model-based tracking technique.7,8 Briefly, custom software created a virtual reconstruction of the testing environment, in which the segmented bone models were manually positioned via ray-traced projections of digitally reconstructed radiographs (DRRs). These manually placed DRRs were then used as an initial guess for the computer to automatically manipulate the bone to a position that maximized the correlations between the DRRs and actual radiographs from kinematic testing. This process was repeated for all frames in a trial. The location and orientation of the femur and tibia were then projected into 3D space, and their motions and positions relative to one another were calculated. Figure 4 shows the final product, with a representative joint contact analysis from a single-level walking trial. The performance of this system has been extensively validated, with precision in the order of 0.1 mm for in vitro testing8 and averaging 0.6 deg/0.5 mm for in vivo tibiofemoral kinematics during running.4

Bottom Line: The affected knees of the subjects were then compared to their unaffected contralateral knees.Affected knees demonstrated significantly more lateral tibial translation than the uninjured contralateral limb in all dynamic activities.This study suggests that MMRT causes significant changes in in vivo knee kinematics and arthrokinematics and that the magnitude of these changes is influenced by dynamic task difficulty.

View Article: PubMed Central - PubMed

Affiliation: Biodynamics Laboratory, University of Pittsburgh, Pittsburgh, Pennsylvania, USA. ; Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.

ABSTRACT

Background: Medial meniscus root tear (MMRT) is a recently recognized yet frequently missed meniscal tear pattern that biomechanically creates an environment approaching meniscal deficiency.

Hypothesis/purpose: The purpose of this study was to assess the effect of MMRT on tibiofemoral kinematics and arthrokinematics during daily activities by comparing the injured knees of subjects with isolated MMRT to their uninjured contralateral knees. The hypothesis was that the injured knee will demonstrate significantly more lateral tibial translation and adduction than the uninjured knee, and that the medial compartment will exhibit significantly different arthrokinematics than the lateral compartment in the affected limb.

Study design: Cross-sectional study; Level of evidence, 3.

Methods: Seven subjects with isolated MMRT were recruited and volumetric, density-based 3-dimensional models of their distal femurs and proximal tibia were created from computed tomography scans. High-speed, biplane radiographs were obtained of both their affected and unaffected knees. Moving 3-dimensional models of tibiofemoral kinematics were calculated using model-based tracking to assess overall kinematic variables and specific measures of tibiofemoral joint contact. The affected knees of the subjects were then compared to their unaffected contralateral knees.

Results: Affected knees demonstrated significantly more lateral tibial translation than the uninjured contralateral limb in all dynamic activities. Additionally, the medial compartment displayed greater amounts of mobility than the lateral compartment in the injured limbs.

Conclusion: This study suggests that MMRT causes significant changes in in vivo knee kinematics and arthrokinematics and that the magnitude of these changes is influenced by dynamic task difficulty.

Clinical relevance: Medial meniscus root tears lead to significant changes in joint arthrokinematics, with increased lateral tibial translation and greater medial compartment excursion. With complete root tears, essentially 100% of circumferential fibers are lost. This study will further our knowledge of meniscal deficiency and osteoarthritis and provide a baseline for more common forms of medial meniscal injuries (vertical, horizontal, radial), with various degrees of circumferential fiber function remaining.

No MeSH data available.


Related in: MedlinePlus