• Journal of Veterinary Science
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• v.21 no.5
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• pp.69.1-69.11
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• 2020

Background: An inappropriate Q angle may affect the biomechanics of the canine patellofemoral joint. Objectives: The purpose of this study was to evaluate the effects of changes in quadriceps angle (Q angle) on patellofemoral joint pressure distribution in dogs. Methods: Eight stifles were positioned at 45, 60, 75, 90, 105, and 120° of flexion in vitro, and 30% body weight was applied through the quadriceps. Patellofemoral contact pressure distribution was mapped and quantified using pressure-sensitive film. For the pressure area, mean pressure, peak pressure, medial peak pressure, and lateral peak pressure, differences between groups according to conditions for changing the Q angle were statistically compared. Results: Increases of 10° of the Q angle result in increases in the pressure area (P = 0.04), mean pressure (P = 0.003), peak pressure, and medial peak pressure (P ≤ 0.01). Increasing the Q angle by 20° increases the pressure area (P = 0.021), mean pressure (P ≤ 0.001), peak pressure (P ≤ 0.01), and medial peak pressure (P ≤ 0.01) significantly, and shows higher mean (P ≤ 0.001) and peak pressures than increasing by 10°. Decreasing the Q angle increases the mean pressure (P = 0.013), peak pressure, and lateral peak pressure (P ≤ 0.001). Conclusions: Both increases and decreases in the Q angle were associated with increased peak patellofemoral pressure, which could contribute to the overloading of the cartilage. Therefore, the abnormal Q angle should be corrected to the physiologically normal value during patellar luxation repair and overcorrection should be avoided.

• Journal of the Korean Arthroscopy Society
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• v.10 no.1
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• pp.33-38
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• 2006

Purpose: This study seeks to address the results of percutaneous lateral release and medial reefing for patients with recurrent patellar dislocation. Materials and Methods: This paper focuses on 27 cases from 25 patients who had a surgical operation at our hospital in a span of eight years and six months from the time of December 1996 to May 2005. The subjects consist of 11 males and 14 females, and their average age was 22.2 years old. All the patients had their trauma history, and the average frequency of dislocation before surgery was 11.5 times. Results: The congruence angle before operation was 23.3 degree on the average, while the lateral patellofemoral angle was -5.7 degree on average. However, the congruence angle after surgery came to -2.4 degree, while the lateral patellofemoral angle recovered to the normal range of within 11.5 degrees. Four cases showed the recurrent dislocation, and two out of those four cases had -35, -12 degrees of their lateral patellofemoral angle respectively and 59, 14 degrees of their congruence angle respectively. Conclusion: Using percutaneous lateral release with medial reefing can be considered as an effective treatment for recurrent patellar dislocation

• Journal of the Korean Society of Radiology
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• v.15 no.6
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• pp.919-926
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• 2021

In this study, we wanted to find out the optimal angle as a modified tangential projection of the patella. In the experiment, we used Kyoto Kagaku's PBU-50 phantom. In the supine position, the F-T angle was set to 95°, 105°, 115°, 125°, 135°, 145°, and Patella tangential projection images were obtained by varying the X-ray tube angle by 5° so that the angle between the X-ray centerline and tibia at each angle was 5~20°. Image J was used for image analysis and the congruence angle, lateral patellofemoral angle, patellofemoral index and contrast to noise ratio(CNR) were also measured. SPSS 22 was used for statistical analysis, and the mean values of congruence angle, patellofemoral angle, patellofemoral index, and CNR were compared with Merchant method through one-way batch analysis and corresponding sample t-test. As a result of the study, in the case of congruence angle, the angle of incidence of the knee-angle X-ray centerline was 105°-72.5° (20° tangential irradiation), 115°-72.5°, 77.5° (15, 20° tangential irradiation), 125°-82.5° (20° tangential irradiation), lateral patellofemoral angle is 115°-72.5°, 77.5° (15, 20° tangential irradiation), 125°-72.5° (10° tangential irradiation), patellofemoral index is 115°-72.5° (15° tangential irradiation) and 125°-72.5° (10° tangential irradiation) were not significantly different from Merchant method (p> .05). In case of CNR, it is not different from Merchant method at 105°-67.5°, 72.5° (15, 20° tangential irradiation), 115°-67.5°, 72.5°, 77.5° (10, 15, 20° tangential irradiation). (P> .05). Based on the results of this study, high diagnostic value images can be obtained by setting the knee angle and the angle of incidence of the X-ray tube to 115°-72.5° (15° tangential irradiation) during the modified tangential examination of the knee bone. It was confirmed.

• 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.4 no.2
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• pp.128-133
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• 2000

Purpose : To compare the changes of the patellar height, patellofemoral alignment and subjective symptom and to compare the effects of patellar tendon harvest after anterior cruciate ligament(ACL) reconstruction using autograft and allograft. Materials and Method : ACL reconstruction was performed on 87 patients who were followed up for minimum 1 year. The group I was 52 patients who were operated with bone-patellar tendon-bone autograft and the group II was 35 patients who were operated with bone-patellar tendon-bone allograft and achilles tendon allograft. At the time of follow-up, the authors evaluated the patellar height by Blackburne-Peel method, Merchant congruence angle, Lateral patellofemoral angle and subjective symptoms were assessed. Results : The patellar heights were significantly decreased from 0.86 preoperatively to 0.80 postoperatively in the group I and from 0.87 preoperatively to 0.83 postoperatively in the group II. There were no significant differences in the lateral patellofemoral angles between the both groups but in the Merchant congruence angle, significant differences were observed in the both groups, from$-1.43^{\circ}$ preoperatively to-$5.43^{\circ}$ postoperalively in the group I and from$-1.53^{\circ}$ preoperatively to$-3.65^{\circ}$ postoperatively in the group II. Conclusion : After ACL reconstruction, the patellofemoral alignment was changed and this kind of changes may be caused by multiple factorials such as harvest of autografts, ACL reconstruction itself, and quadriceps muscle atrophy.

• Physical Therapy Korea
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• v.12 no.2
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• pp.11-19
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• 2005

Patellofemoral pain syndrome (PFPS) is often attributed to malalignment and maltracking of patella within the patellofemoral joint. Most exercise for PFPS has focused on selectively strengthening the vastus medialis oblique muscle (VMO). This study was designed to identify the effect of medial, lateral wedge and difference of Quadriceps angle (Q-angle) on vastus medialis oblique/vastus lateralis muscle (VL) activity ratios. The subjects were twenty young adult males who had not experienced any knee injury. They were asked to perform isometric contraction exercises in three postures using medial and lateral wedge. The EMG activity of the VL and VMO were recorded in three postures by surface electrodes and normalized by %MVC values derived from seated, isometric knee extensions. The normalized EMG activity levels (%MVC) of the VL and VMO for the three postures of the lower extremities were compared using 2-way repeated measures ANOVA with 1 between-subject factor (group), and 1 within-subject factor (wedge). Results of repeated measures of ANOVA's revealed that the medial wedge isometric contraction exercise produced significantly greater EMG activity of VMO/VL ratios in Group I (Q-angle $18^{\circ}$ or less) (p<.05). But, the medial wedge isometric contraction exercise was no significant difference of VMO/VL ratios in Group II (Q-angle $19^{\circ}$ or more) (p>.05). These results have important implications for selective VMO muscle strengthening exercises in PFPS patients.

• Journal of Korean Orthopaedic Sports Medicine
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• v.9 no.2
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• pp.98-103
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• 2010

Purpose: We reported the results of arthroscopically assisted lateral release and medial imbrication for the recurrent patella dislocation. Materials and Methods: Twenty patients (20 knees) underwent arthroscopically assisted surgery for the recurrent patella dislocation. There were 4 males and 16 female. The average age was 20.2 years. All patients had definite trauma history and average follow-up period was 19 months. The surgical results were evaluated according to the Lysholm knee score and the Kujala score. The congruence angle and lateral patellofemoral angle were measured on plain radiograph and the tibial tubercle-trochlear groove distance was calculated on computerized tomography. Results: The median value of preoperative congruence angle was $16.5^{\circ}$ (range, $0.0{\sim}+34^{\circ}$) and the average final follow-up was $-6.4^{\circ}$ (range, $-19{\sim}10^{\circ}$) with statistically significant improvement (p=0.025). The median value of preoperative Lysholm knee score was 70 (range, 63~81) and the final follow-up score had changed to 88 (range, 80~95) with statistically significant improvement (p=0.0341). The median value of preoperative Kujala score was 72 (range, 65~80) and the average final follow-up score showed 87 (range, 80~92) with statistically significant improvement (p=0.024). Recurrent dislocations after surgery occurred in 2 cases, one case which showed positive "thumb to forearm test" had been treated with medial patellofemoral ligament reconstruction. Conclusion: Arthroscopically assisted lateral release and medial imbrication for recurrent patella dislocation without bony malaligmenent showed the effective treatment, but would be inappropriate for the patients with the generalized joint laxity.

• Journal of Korean Orthopaedic Sports Medicine
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• v.9 no.2
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• pp.85-90
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• 2010

Purpose: To evaluate the results of percutaneous lateral release and arthroscopic medial plication for patients with recurrent patella dislocation. Materials and Methods: This study includes the thirty-one cases of patients who have had a surgical operation from March 2001 to March 2008. All the patients had recurrent patella dislocation after trauma history. The average age was 24.2 years old and the average follow up was 47.4 months (minimum 24 months). Results: The preoperative congruence angle, lateral patellofemoral angle, Lysholm score was $24.8^{\circ}$, $-6.2^{\circ}$, 75 points on average respectively. However, the postoperative congruence angle, lateral patellofemoral angle, Lysholm score was improved to normal range: $-2.8^{\circ}$, $10.2^{\circ}$, 95 points on average. Five cases showed the recurrent dislocation after operation. Among them, three cases showed femoral trochlear dysplasia. Conclusion: Percutaneous lateral release and arthroscopic medial plication showed satisfactory results for recurrent patella dislocation with low complication rate. However, in cases with femoral trochlear dysplasia, another surgical treatment may be considered.

• PNF and Movement
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• v.20 no.2
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• pp.189-201
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• 2022

Purpose: The purpose of this study was to investigate the effect of McConnell taping and Kinesio taping on pain and lower extremity joint angles when patients with patellofemoral pain syndrome (PFPS) ascend stairs. Methods: Fifty young adults who were experiencing anterior knee pain due to PFPS were selected as participants. Then, 25 patients were randomly assigned to the McConnell taping group and 25 to the Kinesio taping group. Pain and lower extremity joint angle were measured while ascending stairs before and after the intervention. A paired t-test was performed to evaluate the amount of change in the parameter values after the intervention within the groups, and an independent t-test was used to compare the results of the groups. Results: In the within-group comparisons, a statistically significant difference was found in both groups between the anterior knee pain scale scores recorded before and after the intervention (p < 0.05). A statistically significant difference was also found between the groups (p < 0.05). Comparison of the lower extremity joint angles at initial contact, loading response, terminal stance, and pre-swing within the groups showed that there were statistically significant differences in the hip, knee flexion, abduction, lateral rotation, and dorsiflexion angles in both the McConnell and Kinesio taping groups (p < 0.05). There was also a statistically significant difference in all angles between the groups during the following events (p < 0.05): (1) at initial contact, (2) at loading response (except hip flexion angle), (3) at terminal stance (except hip flexion and lateral rotation angles), and (4) at pre-swing (except hip, knee abduction, and inversion angles). Conclusion: McConnell taping and Kinesio taping both effectively improved the occurrence of knee pain and the lower extremity joint angles during stair ascent in patients with PFPS. However, McConnell taping had a significant impact on pain reduction and lower extremity joint angles compared to Kinesio taping.

• Journal of the Korean Arthroscopy Society
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• v.10 no.1
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• pp.61-69
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• 2006

Purpose: Open lateral release and complete lateral release have been conducted as a surgical method in patients with patellofemoral malalignment. But authors sought to find out the best method by conducting selective release, with minimal excision of the involved lesion, and comparative analyzing the result, as postoperative satisfaction and complication. Materials and Methods: Over the 68 patients of 90 cases who underwent arthroscopic release, among 94 patients of 129 cases who underwent lateral retinacular release, from January 1993 to June 1998 were followed up prospectively. A radiological evaluation of patellar inclination, patellar tilt, congruence angle, and Q-angle and a clinical evaluation of HSS-Knee score and modified patellar score were used for analysis data before operation and data at 1 year and 5 year after operation. Results: According to the radiologic evaluation, the patellar tilt and translation revealed improvement of the results, from $13.4^{\circ}$ and 12.1mm to $3.6^{\circ}$ and 3.8mm with arthroscopic lateral complete release, and from $12.3^{\circ}$ and 11.2mm to $4.8^{\circ}$ and 5.2mm with selective release, and from $13.6^{\circ}$ and 12.3mm to $3.3^{\circ}$ and 3mm with open release. But they were not significantly related to the clinical results. HSS-Knee score was 84.2%(48/57), 81.8%(27/33), 82.1%(32/39) and modified patellar score was 82.5%(47/57), 81.8%(27/33), 82.1%(32/39) respectively, which revealed satisfactory results. And no significant difference among the operative methods were shown. Conclusion: Arthroscopic lateral retinacular release which is one of the surgical method for patellofemoral malalignment enhances rehabilitation and satisfaction of the patient, by releasing the involved retinaculum within lesser surgical extent, compared to open and complete lateral release without complications such as adhesion.