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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

The patient is tested using the KneeM device (A) in the open MRI. (B) The knee is anteriorly constrained by 2 straps, with the lower limb fixed in internal rotation (20°). (C) Four degrees of flexion (0°, 20°, 40°, and 60°) can be adjusted. (D) A dynamometer was used to exert an anterior drawer force of 100 N.
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fig1-2325967114525583: The patient is tested using the KneeM device (A) in the open MRI. (B) The knee is anteriorly constrained by 2 straps, with the lower limb fixed in internal rotation (20°). (C) Four degrees of flexion (0°, 20°, 40°, and 60°) can be adjusted. (D) A dynamometer was used to exert an anterior drawer force of 100 N.

Mentions: The in vivo measurement of rotatory laxity was performed using the KneeM device placed in the open MRI field. The subjects laid on the contralateral side in an open MRI scanner (0.35-T Sigma Ovation HD; General Electric Healthcare, Milwaukee, Wisconsin, USA). The custom-built KneeM device strained the lower limb with 2 straps, 1 on the thigh and 1 on the calf, exerting a manual anterior drawer force of 100 N measured by a dynamometer (Figure 1). All measurements were obtained with the lower limb in a fixed internal rotation of 20° and with the muscles relaxed. The knee was successively flexed from full extension to 20°, 40°, and 60° of flexion. A rigid fixation in each position was held by screws. Four MRI acquisitions were performed in extension and at 20°, 40°, and 60° of flexion (scan parameters: T2-weighted fast spin echo sequences, 40 slices of 0.6-mm thickness; field of view, 240 mm; matrix size, 512 × 256; repetition time [TR], 6220 ms; echo time [TE], 102 ms). Both injured and healthy contralateral knees were successively analyzed. It took approximately 45 minutes for each patient to complete the scan, including the 8 sequences. The examination was painless and therefore without risk of additional injury to the limb.


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)

The patient is tested using the KneeM device (A) in the open MRI. (B) The knee is anteriorly constrained by 2 straps, with the lower limb fixed in internal rotation (20°). (C) Four degrees of flexion (0°, 20°, 40°, and 60°) can be adjusted. (D) A dynamometer was used to exert an anterior drawer force of 100 N.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

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

fig1-2325967114525583: The patient is tested using the KneeM device (A) in the open MRI. (B) The knee is anteriorly constrained by 2 straps, with the lower limb fixed in internal rotation (20°). (C) Four degrees of flexion (0°, 20°, 40°, and 60°) can be adjusted. (D) A dynamometer was used to exert an anterior drawer force of 100 N.
Mentions: The in vivo measurement of rotatory laxity was performed using the KneeM device placed in the open MRI field. The subjects laid on the contralateral side in an open MRI scanner (0.35-T Sigma Ovation HD; General Electric Healthcare, Milwaukee, Wisconsin, USA). The custom-built KneeM device strained the lower limb with 2 straps, 1 on the thigh and 1 on the calf, exerting a manual anterior drawer force of 100 N measured by a dynamometer (Figure 1). All measurements were obtained with the lower limb in a fixed internal rotation of 20° and with the muscles relaxed. The knee was successively flexed from full extension to 20°, 40°, and 60° of flexion. A rigid fixation in each position was held by screws. Four MRI acquisitions were performed in extension and at 20°, 40°, and 60° of flexion (scan parameters: T2-weighted fast spin echo sequences, 40 slices of 0.6-mm thickness; field of view, 240 mm; matrix size, 512 × 256; repetition time [TR], 6220 ms; echo time [TE], 102 ms). Both injured and healthy contralateral knees were successively analyzed. It took approximately 45 minutes for each patient to complete the scan, including the 8 sequences. The examination was painless and therefore without risk of additional injury to the limb.

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