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Vastus medialis obliquus muscle morphology in primary and recurrent lateral patellar instability.

Balcarek P, Oberthür S, Frosch S, Schüttrumpf JP, Stürmer KM - Biomed Res Int (2014)

Bottom Line: Therefore, the purpose of this study was to investigate the morphological parameters of the VMO muscle that delineate its importance in the maintenance of patellofemoral joint stability.No significant difference was found with respect to all measured VMO parameters between primary dislocation, recurrent dislocation, and control subjects with a trend noted for only the VMO cross-sectional area and the VMO muscle-fiber angulation.This finding is notable in that atrophy of the VMO has often been suggested to play an important role in the pathophysiology of an unstable patellofemoral joint.

View Article: PubMed Central - PubMed

Affiliation: Department of Trauma Surgery, Plastic and Reconstructive Surgery, University Medical Center, Robert-Koch-Street 40, 37075 Göttingen, Germany.

ABSTRACT
The morphology of the vastus medialis obliquus (VMO) muscle in the anatomical setting of an unstable patella has not been described. Therefore, the purpose of this study was to investigate the morphological parameters of the VMO muscle that delineate its importance in the maintenance of patellofemoral joint stability. Eighty-two consecutive subjects were prospectively enrolled in this study. The groups were composed of thirty patients with an acute primary patellar dislocation, thirty patients with recurrent patellar dislocation, and twenty-two controls. Groups were adjusted according to sex, age, body mass index, and physical activity. Magnetic resonance imaging was used to measure the VMO cross-sectional area, muscle-fiber angulation, and the craniocaudal extent of the muscle in relation to the patella. No significant difference was found with respect to all measured VMO parameters between primary dislocation, recurrent dislocation, and control subjects with a trend noted for only the VMO cross-sectional area and the VMO muscle-fiber angulation. This finding is notable in that atrophy of the VMO has often been suggested to play an important role in the pathophysiology of an unstable patellofemoral joint.

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Related in: MedlinePlus

Measurement of VMO cross-sectional area. The longitudinal axis of the patella and the femoral shaft axis (dashed line) were established in the central sagittal plane (a). In this sagittal image, the corresponding transverse slice located at the proximal patellar pole, indicated by the red line (c), and the adjacent slices located above (b) and below (d) this reference slice were identified. These transverse planes were used to measure the VMO cross-sectional area by manually drawing disarticulation contours around the muscle boundaries (solid lines in (b-c)). Additionally, the transverse reference image (c) was used to determine the corresponding sagittal slice located centrally in the VMO muscle (dotted line in (c)).
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fig1: Measurement of VMO cross-sectional area. The longitudinal axis of the patella and the femoral shaft axis (dashed line) were established in the central sagittal plane (a). In this sagittal image, the corresponding transverse slice located at the proximal patellar pole, indicated by the red line (c), and the adjacent slices located above (b) and below (d) this reference slice were identified. These transverse planes were used to measure the VMO cross-sectional area by manually drawing disarticulation contours around the muscle boundaries (solid lines in (b-c)). Additionally, the transverse reference image (c) was used to determine the corresponding sagittal slice located centrally in the VMO muscle (dotted line in (c)).

Mentions: Sagittal, coronal, and transverse MR images were obtained in all patients to measure the VMO cross-sectional area, VMO muscle-fiber angulation, and craniocaudal extent of the VMO in relation to the patella. MRI investigations were performed with the knee in full extension and the quadriceps muscle relaxed. Measurements were obtained using the annotation tools of a picture archiving and communications system (PACS) workstation (Centricity, GE Healthcare, St. Gilles, United Kingdom). First, the maximum diameter of the patella and the longitudinal axis of the femoral shaft (dashed line) were established in the central sagittal plane (Figure 1(a)). In this sagittal plane, the corresponding transverse slice located at the proximal patellar pole (red solid line in Figure 1(a)) was identified (Figure 1(c)). Using this transverse image as the reference slice, one trained observer manually measured the VMO cross-sectional area in this slice and in the adjacent slices straight above and below this reference slice (MRI slice thickness 3.5 mm) by drawing disarticulation contours around the muscle boundaries (red solid line and white solid lines in Figures 1(b)–1(d)). All three cross-sectional area measurements were subsumed to one value mimicking the three-dimensional VMO muscle structure. Next, the reference slice in Figure 1(c) was used to determine the corresponding sagittal slice centrally located in the VMO muscle (dotted line in Figure 1(c)). The longitudinal axis of the femoral shaft was assigned to this corresponding plane (dashed line in Figure 2(a)). This sagittal plane, shown in Figure 2(a), was then used to measure muscle-fiber angulation in relation to the longitudinal axis of the femoral shaft. Finally, to ascertain the craniocaudal extent of the VMO in relation to the patella, the most caudal end-point of the VMO was determined in a sagittal plane (red dot in Figure 2(a)). This point was then assigned to the corresponding sagittal plane centrally located through the longitudinal axis of the patella (Figure 2(b)). The craniocaudal VMO extent was then measured as the distance between this point and the proximal patellar pole (double-headed arrow in Figure 2(b)).


Vastus medialis obliquus muscle morphology in primary and recurrent lateral patellar instability.

Balcarek P, Oberthür S, Frosch S, Schüttrumpf JP, Stürmer KM - Biomed Res Int (2014)

Measurement of VMO cross-sectional area. The longitudinal axis of the patella and the femoral shaft axis (dashed line) were established in the central sagittal plane (a). In this sagittal image, the corresponding transverse slice located at the proximal patellar pole, indicated by the red line (c), and the adjacent slices located above (b) and below (d) this reference slice were identified. These transverse planes were used to measure the VMO cross-sectional area by manually drawing disarticulation contours around the muscle boundaries (solid lines in (b-c)). Additionally, the transverse reference image (c) was used to determine the corresponding sagittal slice located centrally in the VMO muscle (dotted line in (c)).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4020533&req=5

fig1: Measurement of VMO cross-sectional area. The longitudinal axis of the patella and the femoral shaft axis (dashed line) were established in the central sagittal plane (a). In this sagittal image, the corresponding transverse slice located at the proximal patellar pole, indicated by the red line (c), and the adjacent slices located above (b) and below (d) this reference slice were identified. These transverse planes were used to measure the VMO cross-sectional area by manually drawing disarticulation contours around the muscle boundaries (solid lines in (b-c)). Additionally, the transverse reference image (c) was used to determine the corresponding sagittal slice located centrally in the VMO muscle (dotted line in (c)).
Mentions: Sagittal, coronal, and transverse MR images were obtained in all patients to measure the VMO cross-sectional area, VMO muscle-fiber angulation, and craniocaudal extent of the VMO in relation to the patella. MRI investigations were performed with the knee in full extension and the quadriceps muscle relaxed. Measurements were obtained using the annotation tools of a picture archiving and communications system (PACS) workstation (Centricity, GE Healthcare, St. Gilles, United Kingdom). First, the maximum diameter of the patella and the longitudinal axis of the femoral shaft (dashed line) were established in the central sagittal plane (Figure 1(a)). In this sagittal plane, the corresponding transverse slice located at the proximal patellar pole (red solid line in Figure 1(a)) was identified (Figure 1(c)). Using this transverse image as the reference slice, one trained observer manually measured the VMO cross-sectional area in this slice and in the adjacent slices straight above and below this reference slice (MRI slice thickness 3.5 mm) by drawing disarticulation contours around the muscle boundaries (red solid line and white solid lines in Figures 1(b)–1(d)). All three cross-sectional area measurements were subsumed to one value mimicking the three-dimensional VMO muscle structure. Next, the reference slice in Figure 1(c) was used to determine the corresponding sagittal slice centrally located in the VMO muscle (dotted line in Figure 1(c)). The longitudinal axis of the femoral shaft was assigned to this corresponding plane (dashed line in Figure 2(a)). This sagittal plane, shown in Figure 2(a), was then used to measure muscle-fiber angulation in relation to the longitudinal axis of the femoral shaft. Finally, to ascertain the craniocaudal extent of the VMO in relation to the patella, the most caudal end-point of the VMO was determined in a sagittal plane (red dot in Figure 2(a)). This point was then assigned to the corresponding sagittal plane centrally located through the longitudinal axis of the patella (Figure 2(b)). The craniocaudal VMO extent was then measured as the distance between this point and the proximal patellar pole (double-headed arrow in Figure 2(b)).

Bottom Line: Therefore, the purpose of this study was to investigate the morphological parameters of the VMO muscle that delineate its importance in the maintenance of patellofemoral joint stability.No significant difference was found with respect to all measured VMO parameters between primary dislocation, recurrent dislocation, and control subjects with a trend noted for only the VMO cross-sectional area and the VMO muscle-fiber angulation.This finding is notable in that atrophy of the VMO has often been suggested to play an important role in the pathophysiology of an unstable patellofemoral joint.

View Article: PubMed Central - PubMed

Affiliation: Department of Trauma Surgery, Plastic and Reconstructive Surgery, University Medical Center, Robert-Koch-Street 40, 37075 Göttingen, Germany.

ABSTRACT
The morphology of the vastus medialis obliquus (VMO) muscle in the anatomical setting of an unstable patella has not been described. Therefore, the purpose of this study was to investigate the morphological parameters of the VMO muscle that delineate its importance in the maintenance of patellofemoral joint stability. Eighty-two consecutive subjects were prospectively enrolled in this study. The groups were composed of thirty patients with an acute primary patellar dislocation, thirty patients with recurrent patellar dislocation, and twenty-two controls. Groups were adjusted according to sex, age, body mass index, and physical activity. Magnetic resonance imaging was used to measure the VMO cross-sectional area, muscle-fiber angulation, and the craniocaudal extent of the muscle in relation to the patella. No significant difference was found with respect to all measured VMO parameters between primary dislocation, recurrent dislocation, and control subjects with a trend noted for only the VMO cross-sectional area and the VMO muscle-fiber angulation. This finding is notable in that atrophy of the VMO has often been suggested to play an important role in the pathophysiology of an unstable patellofemoral joint.

Show MeSH
Related in: MedlinePlus