• Korean Journal of Radiology
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• v.23 no.6
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• pp.674-687
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• 2022

Patellofemoral instability (PFI) is common in pediatric knee injuries. PFI results from loss of balance in the dynamic relationship of the patella in the femoral trochlear groove. Patellar lateral dislocation, which is at the extreme of the PFI, results from medial stabilizer injury and leads to the patella hitting the lateral femoral condyle. Multiple contributing factors to PFI have been described, including anatomical variants and altered biomechanics. Femoral condyle dysplasia is a major risk factor for PFI. Medial stabilizer injury contributes to PFI by creating an imbalance in dynamic vectors of the patella. Increased Q angle, femoral anteversion, and lateral insertion of the patellar tendon are additional contributing factors that affect dynamic vectors on the patella. An imbalance in the dynamics results in patellofemoral malalignment, which can be recognized by the presence of patella alta, patellar lateral tilt, and lateral subluxation. Dynamic cross-sectional images are useful for in vivo tracking of the patella in patients with PFI. Therapeutic approaches aim to restore normal patellofemoral dynamics and prevent persistent PFI. In this article, the imaging findings of PFI, including risk factors and characteristic findings of acute lateral patellar dislocation, are reviewed. Non-surgical and surgical approaches to PFI in pediatric patients are discussed.

• Journal of the Korean Arthroscopy Society
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• v.10 no.2
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• pp.214-218
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• 2006

Purpose: We describe a new technique of arthroscopic medial plication using pull-out suture with consideration of anatomical location of medial patellofemoral ligament for the treatment of acute or recurrent patellar dislocation. Operative technique: Under arthroscopic examination, sutures are passed through the medial capsule, at which medial patellofemoral ligament is located, from outside to inside of knee joint. Three guide wires are inserted from anterior surface of the patella to upper half of its medial border. Intraarticular portions of sutures are pulled out toward anterior surface of the patella through bony tunnels. Under appropriate tension, the sutures are tied after performing lateral retinacular release. Conclusion: As suturing medial patellofemoral ligament, this technique can maximize the effect of medial plication and can correct subluxation and tilt of the patella. It seems to be a minimally invasive, easy and effective method for the treatment of acute or recurrent patellar dislocation.

• Journal of radiological science and technology
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• v.42 no.6
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• pp.423-428
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• 2019

The Precise measurement of the knee's Congruence angle is required for diagnosis of patella dislocation. The purpose of this study is to consider the distortion diagram and usefulness about the test of the bilateral side and one side through the evaluating congruence angle from Merchant view of patellofemoral joint to central X-ray. We've evaluated the sulcus angle and Congruence angle following central X-ray's changes when we took Merchant view of patellofemoral joint aimed to right lower limb from human whole body phantom. The subject of the evaluation was classified as normal group and varus group, and the varus group has experimented with External rotation of legs as 15° and 30°. When normal groups result as 0, 7.5, 15 cm, it was measured as 17.25 ± 1.34°, 19.60 ± 1.41°, 20.55 ± 1.77° each. The gap between minimal and maximum angle was 3.3°, and the value was shown as getting bigger when it further away from the centeral X-ray. When Congruence angle in 15° varus group was 0, 7.5, 15 cm, it was each 16.45 ± 1.34°, 17.10 ± 0.99°, 17.80 ± 1.13°. And when Congruence angle in 30° varus group was 0, 7.5, 15 cm, it was measured each 18.35 ± 1.63°, 18.95 ± 1.06°, 19.60 ± 1.41°. The difference between minimum and maximum of angle in 15° varus group and 30° varus group was each 1.35° and 1.25°, the angles have shown as increasing the further away from the center. The patellofemoral joint showed that the congruence angle increases as the further away from Central X-ray, and also it is judged that is possible to change the congruence angle by a degree of varus knee. Thus, accurate measurement of the congruence angle is shown to advantage that methods for examining by split each side at two times than methods for examining both sides at a time. Therefore, it is expected to helpful on the diagnostic side of patella dislocation and subluxation.

• Korean Journal of Digital Imaging in Medicine
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• v.12 no.1
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• pp.43-50
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• 2010

The representative study of Patellofemoral Joint Merchant method can show the view for inspection of the sulcus angle, congruence angle and diagnose whether there are the vertical fractures and recognize the degree of dislocation and patella subluxation. However, anatomical correlation about the degree of knee joint curvature changes during position adjustment and distortion of the image reduces reproducibility. In order to resolve these problems, Merchant method needs to use assisting device which reduces the occurrence of repeat projection and effectively to increase unification of examination and the consistency of the image. However, there are disadvantages for patients who take other examinations. For example, they have to change the position for every examination and it might cause the patient's discomfort and increase of examination time. In this study, we newly devised commercial assisting device which improves the reproducibility of the images and reduces inconvenience of patients movement. Further research should be taken to obtain a image without patient's movement and to reduce the time of the examination than existing method.

• Journal of the Korean Orthopaedic Association
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• v.56 no.2
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• pp.134-141
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• 2021

Purpose: Patellar dislocations have a range of causes. This study examined the results of treatment aimed at balancing soft tissues around the patella. Materials and Methods: Thirty-two patellar dislocations in 28 patients (21 females and seven males) were examined. The mean patient age at the time of surgery was 11.5 years, and the mean follow-up period was 4.6 years. Dislocations were 19 chronic, six habitual, six congenital, and one acute. Soft tissue balancing surgery included lateral capsular release, medial capsular plication, and inferolateral transfer of the vastus medialis obliquus. Medial transfer of the patellar tendon, partial strip of the rectus femoris and patella tendon, and distal femoral osteotomy were also performed selectively. The preoperative Q angle, femoral anteversion angle, tibial external rotation angle, tibial tubercle-trochlear groove distance (TT-TG distance), mechanical femoral-tibial angle, and femoral trochlear dysplasia according to Dejour were measured, and the pre- and postoperative Lysholm-Tegner scores were used to analyze the clinical results. Results: The mean preoperative Q angle, TT-TG distance, femoral anteversion angle, tibial external rotation angle, mechanical femoraltibia angle, and Lysholm-Tegner score were 9.3°, 15.5 mm, 25.6°, 30.4°, 3.0°, and 75.8, respectively. Eleven patients had systemic ligament laxity with a Beighton score of five or more. Twenty-two patients had femoral trochlear dysplasia: four type A (3 patients), 16 type B (15 patients), one type C (1 patient), and four type D (3 patients). Of the 32 cases, 28 were corrected successfully by the first operation. Of four cases of postoperative subluxation, three were corrected by the second operation, and one of them was corrected after a third operation. The last patient is currently being followed-up. The mean Lysholm-Tegner score improved to 85.6 after the operation. Conclusion: Correcting all the causes of patella dislocation simultaneously is difficult. Nevertheless, satisfactory outcomes were obtained with soft tissue balancing surgery around the patella and a corrective osteotomy for an abnormal mechanical axis of the femur-tibia and torsion.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.8 no.1
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• pp.75-85
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• 2013

Objectives: The purpose of this case report is to investigate the effect of exercise for vastus medialis to knee pain patients with patello-femoral pain syndrome. Methods: Two patients with patello-femoral pain syndrome were treated by exercise for vastus medialis. To measure the outcome of the patients' improvement, we observed the X-ray of both knee sky-line view, Numerical Rating Scale(NRS), and Western Ontario and McMaster Universities(WOMAC) index. Results: After being treated by exercise for vastus medialis, the patients' X-ray of both knee sky-line view, Numerical Rating Scale(NRS), and Western Ontario and McMaster Universities(WOMAC) index were significantly improved. Conclusions: These results suggest that exercise for vastus medialis is effective treatment to patients with patello-femoral pain syndrome.