Does patellar tilt affect the outcome of total knee arthroplasty? a retrospective study

<p><strong>Background</strong>: Patellofemoral joint management during total knee replacement remains a controversial topic among knee surgeons. The purpose of this study is to evaluate the influence of resurfaced patellar component tilt on the functional outcome of total knee arthroplasty.</p><p><strong>Methods</strong>: This is a retrospective study reviewing all the patients who underwent total knee arthroplasty in our institution, operated by a single surgeon using a single implant design.</p><p><strong>Results:</strong> A total of 48 patients and 82 knees were enrolled into this study. Patients were evaluated by Oxford knee score, knee society score, Melbourne patellar score, anteroposterior, lateral, and Merchant’s view radiographs. The patellar tilt was divided into three grades according the measurement obtained from knee radiographs.</p><p><strong>Conclusions: </strong>A higher degree of patella tilt (more than 10 degree) is associated with poor outcome following total knee arthroplasty. Melbourne patella score is more sensitive than knee society score and Oxford score in assessing the effect of patella tilt on the outcome of total knee arthroplasty.</p>

Morphological study of the vastus medialis oblique in recurrent patellar dislocation based on magnetic resonance images

Background: To investigate the morphological parameters of the vastus medialis obliquus (VMO) muscle and delineate its importance in the maintenance of patellofemoral joint stability.Methods: The magnetic resonance imaging (MRI) data of seventy-five knees (fifty-four patients) with recurrent lateral patella dislocation (LPD) and seventy-five knees (seventy patients) without recurrent LPD were retrospectively analysed. Five morphological parameters related to the VMO (elevation in the sagittal plane and coronal plane, craniocaudal extent, muscle-fibre angulation, cross-sectional area ratio) and two patella tilt parameters (patella tilt angle, bisect offset ratio) were measured in MR images. The independent-samples t test or chi-square test was used for statistical comparisons.Results: The mean ages of the patients in the recurrent LPD group and control group were 22.1 ± 9.9 years and 24.0 ± 6.5 years, respectively. Eighteen out of seventy-five (24%) patients MRI showed VMO injuries. Compared with the control group, the patients with recurrent LPD showed significantly higher sagittal VMO elevation (10.4 ± 2.3 mm vs 4.1 ± 1.9 mm), coronal VMO elevation (15.9 ± 5.7 mm vs 3.9 ± 3.7 mm), muscle-fibre angulation (35.4 ± 8.0° vs 27.9 ± 6.3°), patella tilt angle (25.9 ± 10.7° vs 9.1 ± 5.2°), and bisect offset ratio values (0.9 ± 0.3 vs 0.5 ± 0.1) and significantly lower craniocaudal extent (13.7 ± 5.3 mm vs 16.7 ± 5.1 mm) and cross-sectional area ratio values (0.05 ± 0.02 vs 0.07 ± 0.02).Conclusions: The results showed that abnormalities in the VMO and patella tilt were clearly present in recurrent LPD patients compared with normal people.

Morphological study of the vastus medialis oblique in recurrent patellar dislocation based on magnetic resonance images

Background To investigate the morphological parameters of the vastus medialis obliquus (VMO) muscle and delineate its importance in the maintenance of patellofemoral joint stability. Methods The magnetic resonance imaging data of seventy-five knees (fifty-four patients) with recurrent lateral patella dislocation (LPD) and seventy-five knees (seventy patients) without recurrent LPD were retrospectively analysed. Five morphological parameters related to the VMO (elevation in the sagittal plane and coronal plane, craniocaudal extent, muscle-fibre angulation, cross-sectional area ratio) and two patella tilt parameters (patella tilt angle, bisect offset ratio) were measured in MR images. The independent-samples t test or chi-square test was used for statistical comparisons. Results The mean ages of the patients in the recurrent LPD group and control group were 22.1 ± 9.9 years and 24.0 ± 6.5 years, respectively. Eighteen out of seventy-five (24%) patients MRI showed VMO injuries. Compared with the control group, the patients with recurrent LPD showed significantly higher sagittal VMO elevation (10.4 ± 2.3 mm vs. 4.1 ± 1.9 mm), coronal VMO elevation (15.9 ± 5.7 mm vs. 3.9 ± 3.7 mm), muscle-fibre angulation (35.4 ± 8.0° vs. 27.9 ± 6.3°), patella tilt angle (25.9 ± 10.7° vs. 9.1 ± 5.2°), and bisect offset ratio values (0.9 ± 0.3 vs. 0.5 ± 0.1) and significantly lower craniocaudal extent (13.7 ± 5.3 mm vs. 16.7 ± 5.1 mm) and cross-sectional area ratio values (0.05 ± 0.02 vs. 0.07 ± 0.02). Conclusions The results showed that abnormalities in the VMO and patella tilt were clearly present in recurrent LPD patients compared with normal people.

Morphological study of the vastus medialis oblique in recurrent patellar dislocation based on magnetic resonance images

Background: To investigate the morphological parameters of the vastus medialis obliquus (VMO) muscle and delineate its importance in the maintenance of patellofemoral joint stability.Methods: The magnetic resonance imaging (MRI) data of seventy-five knees (fifty-four patients) with recurrent lateral patella dislocation (LPD) and seventy-five knees (seventy patients) without recurrent LPD were retrospectively analysed. Five morphological parameters related to the VMO (elevation in the sagittal plane and coronal plane, craniocaudal extent, muscle-fibre angulation, cross-sectional area ratio) and two patella tilt parameters (patella tilt angle, bisect offset ratio) were measured in MR images. The independent-samples t test or chi-square test was used for statistical comparisons.Results: The mean ages of the patients in the recurrent LPD group and control group were 22.1 ± 9.9 years and 24.0 ± 6.5 years, respectively. Eighteen out of seventy-five (24%) patients MRI showed VMO injuries. Compared with the control group, the patients with recurrent LPD showed significantly higher sagittal VMO elevation (10.4 ± 2.3 mm vs 4.1 ± 1.9 mm), coronal VMO elevation (15.9 ± 5.7 mm vs 3.9 ± 3.7 mm), muscle-fibre angulation (35.4 ± 8.0° vs 27.9 ± 6.3°), patella tilt angle (25.9 ± 10.7° vs 9.1 ± 5.2°), and bisect offset ratio values (0.9 ± 0.3 vs 0.5 ± 0.1) and significantly lower craniocaudal extent (13.7 ± 5.3 mm vs 16.7 ± 5.1 mm) and cross-sectional area ratio values (0.05 ± 0.02 vs 0.07 ± 0.02).Conclusions: The results showed that abnormalities in the VMO and patella tilt were clearly present in recurrent LPD patients compared with normal people.

Morphological study of the vastus medialis oblique in recurrent patellar dislocation based on magnetic resonance images

Background: To investigate the morphological parameters of the vastus medialis obliquus (VMO) muscle and delineate its importance in the maintenance of patellofemoral joint stability. Methods: The magnetic resonance imaging (MRI) data of 75 knees (54 patients) with recurrent lateral patella dislocation (LPD) and 75 knees (70 patients) without recurrent LPD were retrospectively analysed. Five morphological parameters related to the VMO (elevation in the sagittal plane and coronal plane, craniocaudal extent, muscle-fibre angulation, cross-sectional area ratio) and two patella tilt parameters (patella tilt angle, bisect offset ratio) were measured in MRI images. The independent-samples t test or chi-square test was used for statistical comparisons. Results: The mean ages of the patients in the recurrent LPD group and control group were 22.1 ± 9.9 years and 24.0 ± 6.5 years, respectively. MRI demonstrated that 24% (18 of 75) VMO injuries were found in recurrent LPD patients. Compared with the control group, the patients with recurrent LPD showed significantly higher sagittal VMO elevation (10.4 ± 2.3 mm vs 4.1 ± 1.9 mm), coronal VMO elevation (15.9 ± 5.7 mm vs 3.9 ± 3.7 mm), muscle-fibre angulation (35.4 ± 8.0° vs 27.9 ± 6.3°), patella tilt angle (25.9 ± 10.7° vs 9.1 ± 5.2°), and bisect offset ratio values (0.9 ± 0.3 vs 0.5 ± 0.1) and significantly lower craniocaudal extent (13.7 ± 5.3 mm vs 16.7 ± 5.1 mm) and cross-sectional area ratio values (0.05 ± 0.02 vs 0.07 ± 0.02). Conclusions: The results showed that abnormalities in the VMO and patella tilt were clearly present in recurrent LPD patients compared with normal people.

Morphological study of vastus medialis oblique in recurrent patellar dislocation based on magnetic resonance images

Purpose To investigate the morphological parameters of the vastus medialis obliquus (VMO) muscle and delineate its importance in the maintenance of patellofemoral joint stability.Methods The magnetic resonance imaging (MRI) data of 75 knees (54 patients) with recurrent lateral patella dislocation (LPD) and 75 knees (70 patients with similar age, gender and body mass index) were retrospectively analyzed. Five morphological parameters related to VMO (elevation on sagittal plane and coronal plane, cross-sectional area ratio, craniocaudal extent, muscle-fiber angulation,) and two parameters of patella tilt (patella tilt angle, bisect offset ratio) were measured in MRI images, and the types of trochlear in each patient were recorded. Finally, the differences of these parameters between the two groups were analyzed.Results Compared with the control group, the patients with recurrent LPD showed significantly higher in sagittal VMO elevation (10.4 ± 2.3 mm vs 4.1 ± 1.9 mm), coronal VMO elevation (15.9 ± 5.7 mm vs 3.9 ± 3.7 mm), muscle-fiber angulation (35.4 ± 8.0° vs 27.9 ± 6.3°), patella tilt angle (25.9 ± 10.7° vs 9.1 ± 5.2°), and bisect offset ratio values (0.9 ± 0.3 vs 0.5 ± 0.1), and significantly lower in craniocaudal extent (13.7 ± 5.3mm vs 16.7 ± 5.1 mm) and cross-sectional area ratio values (0.07 ± 0.02 vs 0.05 ± 0.02).Conclusions The results showed that the abnormality of VMO were clearly present in recurrent LPD patients compared with normal people, which may be an important factor of patella tilt in LPD patients, so it is necessary to focus on injury condition of VMO during preoperative evaluation.