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A Preliminary In Vivo Assessment of Anterior Cruciate Ligament-Deficient Knee Kinematics With the KneeM Device: A New Method to Assess Rotatory Laxity Using Open MRI.

Tardy N, Marchand P, Kouyoumdjian P, Blin D, Demattei C, Asencio G - Orthop J Sports Med (2014)

Bottom Line: However, significant differences in the anterior translation of the lateral compartment were observed between ACL-deficient and intact contralateral knees at 0° and 20° of flexion (P = .005 and P = .002, respectively).Moreover, this device seemed to allow a "mechanized pivot shift" and allowed reproduction of the "pivot" phase in the MRI field between 20° and 40° of flexion.This device could be used for diagnostic purposes or to investigate the outcomes of ACL reconstructions.

View Article: PubMed Central - PubMed

Affiliation: Orthopaedic Department, CHU de Nîmes, Nîmes, France.

ABSTRACT

Background: Methods of objectively measuring rotational knee laxity are either experimental or difficult to use in daily practice. A new method has been developed to quantitatively assess rotatory laxity using an open MRI system and new tool, the KneeM device.

Purpose/hypothesis: To perform a preliminary evaluation of a novel knee rotation measurement device to assess knee kinematics during flexion in an MRI field, in both anterior cruciate ligament (ACL)-deficient and healthy contralateral knees. The hypothesis was that the KneeM device would allow in vivo reproduction and analysis of knee kinematics during flexion in healthy and ACL-deficient knees.

Study design: Controlled laboratory study.

Methods: Ten subjects (7 men and 3 women; mean age ± standard deviation, 32.3 ± 9.4 years) with ACL-deficient knees and contralateral uninjured knees participated in the study. An open MRI was performed with the KneeM device at a mean 4.9 months (range, 3.0-7 months) after ACL injury. The device exerted on the knee an anterior drawer force of 100 N, with an internal rotation of 20°, through the range of flexion (0°, 20°, 40°, and 60°). Both ACL-deficient and healthy contralateral knees were analyzed using the Iwaki method.

Results: There was no statistical difference of anterior translation in the medial compartment between intact and ACL-deficient knees at all degrees of flexion. However, significant differences in the anterior translation of the lateral compartment were observed between ACL-deficient and intact contralateral knees at 0° and 20° of flexion (P = .005 and P = .002, respectively). Between 20° and 40°, the lateral plateau of ACL-deficient knees translated 7.7 mm posteriorly, whereas the medial compartment remained stable, reflecting a sudden external rotation of the lateral plateau under the femoral condyle.

Conclusion: This preliminary study suggests that measurement of tibiofemoral movements in both compartments during flexion using the KneeM device was useful for quantifying rotatory laxity in ACL-deficient knees. Moreover, this device seemed to allow a "mechanized pivot shift" and allowed reproduction of the "pivot" phase in the MRI field between 20° and 40° of flexion.

Clinical relevance: This device could be used for diagnostic purposes or to investigate the outcomes of ACL reconstructions.

No MeSH data available.


Related in: MedlinePlus

Measurement of the femorotibial relationship using the Iwaki method. Distance “D” is measured in the lateral compartment of an extended knee. Measurement of D is taken from the flexion facet centers (FFCs) to the vertical line drawn from the posterior tibial cortex.
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fig2-2325967114525583: Measurement of the femorotibial relationship using the Iwaki method. Distance “D” is measured in the lateral compartment of an extended knee. Measurement of D is taken from the flexion facet centers (FFCs) to the vertical line drawn from the posterior tibial cortex.

Mentions: We used Osirix software (Pixmeo, Geneva, Switzerland) to measure, according to the Iwaki method,20 the anteroposterior tibial translation with respect to the femoral condyles (distance “D”) at all angles of flexion for both ACL-deficient and healthy knees. The distance was recorded on sagittal T1-weighted images scanned at each center of the medial and lateral compartments by measuring the distance between the tangent line of the posterior tibial cortex and the center of a circle materializing the femoral condyle, called the flexion facet center (FFC)20 (Figure 2). To determine the center of each compartment, we used an initial 3-dimensional multiplanar reconstruction scan to choose the slice that included the medial edge of the fibular head as a landmark for the center of the lateral compartment and the attachment of the medial head of the gastrocnemius for the medial compartment. To determine the FFC, we took the center of a circle that encompassed the posterior aspect of each condyle, medial and lateral, that has been shown to have a relatively circular form in the sagittal plane.53 The FFC can be used as a reliable reference point for the position of each condyle.20 The reference point for the tibia was the tangent line to the posterior tibial cortex, perpendicular to a horizontal line parallel to the tibial plateau. It is important to note that according to the Iwaki method, the distance “D” is inversely proportional to the anterior tibial translation. The distance “D” is smaller for ACL-deficient knees than for healthy knees. Analysis by an experienced examiner took approximately 10 minutes for the 8 measures (2 knees × 4 angles).


A Preliminary In Vivo Assessment of Anterior Cruciate Ligament-Deficient Knee Kinematics With the KneeM Device: A New Method to Assess Rotatory Laxity Using Open MRI.

Tardy N, Marchand P, Kouyoumdjian P, Blin D, Demattei C, Asencio G - Orthop J Sports Med (2014)

Measurement of the femorotibial relationship using the Iwaki method. Distance “D” is measured in the lateral compartment of an extended knee. Measurement of D is taken from the flexion facet centers (FFCs) to the vertical line drawn from the posterior tibial cortex.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2 - License 3
Show All Figures
getmorefigures.php?uid=PMC4555568&req=5

fig2-2325967114525583: Measurement of the femorotibial relationship using the Iwaki method. Distance “D” is measured in the lateral compartment of an extended knee. Measurement of D is taken from the flexion facet centers (FFCs) to the vertical line drawn from the posterior tibial cortex.
Mentions: We used Osirix software (Pixmeo, Geneva, Switzerland) to measure, according to the Iwaki method,20 the anteroposterior tibial translation with respect to the femoral condyles (distance “D”) at all angles of flexion for both ACL-deficient and healthy knees. The distance was recorded on sagittal T1-weighted images scanned at each center of the medial and lateral compartments by measuring the distance between the tangent line of the posterior tibial cortex and the center of a circle materializing the femoral condyle, called the flexion facet center (FFC)20 (Figure 2). To determine the center of each compartment, we used an initial 3-dimensional multiplanar reconstruction scan to choose the slice that included the medial edge of the fibular head as a landmark for the center of the lateral compartment and the attachment of the medial head of the gastrocnemius for the medial compartment. To determine the FFC, we took the center of a circle that encompassed the posterior aspect of each condyle, medial and lateral, that has been shown to have a relatively circular form in the sagittal plane.53 The FFC can be used as a reliable reference point for the position of each condyle.20 The reference point for the tibia was the tangent line to the posterior tibial cortex, perpendicular to a horizontal line parallel to the tibial plateau. It is important to note that according to the Iwaki method, the distance “D” is inversely proportional to the anterior tibial translation. The distance “D” is smaller for ACL-deficient knees than for healthy knees. Analysis by an experienced examiner took approximately 10 minutes for the 8 measures (2 knees × 4 angles).

Bottom Line: However, significant differences in the anterior translation of the lateral compartment were observed between ACL-deficient and intact contralateral knees at 0° and 20° of flexion (P = .005 and P = .002, respectively).Moreover, this device seemed to allow a "mechanized pivot shift" and allowed reproduction of the "pivot" phase in the MRI field between 20° and 40° of flexion.This device could be used for diagnostic purposes or to investigate the outcomes of ACL reconstructions.

View Article: PubMed Central - PubMed

Affiliation: Orthopaedic Department, CHU de Nîmes, Nîmes, France.

ABSTRACT

Background: Methods of objectively measuring rotational knee laxity are either experimental or difficult to use in daily practice. A new method has been developed to quantitatively assess rotatory laxity using an open MRI system and new tool, the KneeM device.

Purpose/hypothesis: To perform a preliminary evaluation of a novel knee rotation measurement device to assess knee kinematics during flexion in an MRI field, in both anterior cruciate ligament (ACL)-deficient and healthy contralateral knees. The hypothesis was that the KneeM device would allow in vivo reproduction and analysis of knee kinematics during flexion in healthy and ACL-deficient knees.

Study design: Controlled laboratory study.

Methods: Ten subjects (7 men and 3 women; mean age ± standard deviation, 32.3 ± 9.4 years) with ACL-deficient knees and contralateral uninjured knees participated in the study. An open MRI was performed with the KneeM device at a mean 4.9 months (range, 3.0-7 months) after ACL injury. The device exerted on the knee an anterior drawer force of 100 N, with an internal rotation of 20°, through the range of flexion (0°, 20°, 40°, and 60°). Both ACL-deficient and healthy contralateral knees were analyzed using the Iwaki method.

Results: There was no statistical difference of anterior translation in the medial compartment between intact and ACL-deficient knees at all degrees of flexion. However, significant differences in the anterior translation of the lateral compartment were observed between ACL-deficient and intact contralateral knees at 0° and 20° of flexion (P = .005 and P = .002, respectively). Between 20° and 40°, the lateral plateau of ACL-deficient knees translated 7.7 mm posteriorly, whereas the medial compartment remained stable, reflecting a sudden external rotation of the lateral plateau under the femoral condyle.

Conclusion: This preliminary study suggests that measurement of tibiofemoral movements in both compartments during flexion using the KneeM device was useful for quantifying rotatory laxity in ACL-deficient knees. Moreover, this device seemed to allow a "mechanized pivot shift" and allowed reproduction of the "pivot" phase in the MRI field between 20° and 40° of flexion.

Clinical relevance: This device could be used for diagnostic purposes or to investigate the outcomes of ACL reconstructions.

No MeSH data available.


Related in: MedlinePlus