A 3D model analysis of patellofemoral joint: effect of anterior translation and internal rotation of tibia

Purpose. The purpose of this study was to determine whether intraoperative prereconstruction stability measurements and/or patient characteristics were associated with final knee stability after computer-assisted ACL reconstruction.Methods. This was a retrospective review of all patients who underwent computer-assisted single-bundle ACL reconstruction by a single surgeon. Prereconstruction intraoperative stability measurements were correlated with patient characteristics and postreconstruction stability measurements. 143 patients were included (87 male and 56 female). Average age was 29.8 years (SD ± 11.8).Results. Females were found to have significantly more pre- and postreconstruction internal rotation than males (P< 0.001 andP= 0.001, resp.). Patients with additional intra-articular injuries demonstrated more prereconstruction anterior instability than patients with isolated ACL tears (P< 0.001). After reconstruction, these patients also had higher residual anterior translation (P= 0.01). Among all patients with ACL reconstructions, the percent of correction of anterior translation was found to be significantly higher than the percent of correction for internal or external rotation (P< 0.001).Conclusion. Anterior translation was corrected the most using a single-bundle ACL reconstruction. Females had higher pre- and postoperative internal rotation. Patients with additional injuries had greater original anterior translation and less operative correction of anterior translation compared to patients with isolated ACL tears.

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A biomechanical study after combined reconstruction of the anterior cruciate and anterolateral ligaments: Comparison between anatomic anterolateral ligament reconstruction and lateral tenodesis using the modified Lemaire technique

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967120s00003 ◽

2020 ◽

Vol 8 (2_suppl) ◽

pp. 2325967120S0000

Author(s):

Jean-Romain Delaloye ◽

christoph Hartog ◽

Samuel Blatter ◽

Dominik Müller ◽

Michel Schläppi ◽

...

Keyword(s):

Internal Rotation ◽

Ligament Reconstruction ◽

Cruciate Ligament ◽

Anterolateral Ligament ◽

The Other ◽

Anterior Translation ◽

Anterior Cruciate ◽

Deficient Knee ◽

Lemaire Procedure ◽

Intact Knee

Objectives: To determine the stabilizing role of the anterolateral ligament reconstruction (ALLR) and the modified Lemaire lateral extraarticular tenodesis (LET) performed in combination with anterior cruciate ligament reconstruction (ACLR) and to determine if one of these two procedures was superior to the other. Methods: Six non paired cadaveric knees were tested with a 6 degrees of freedom robotic system (KUKA Robotics). Internal rotation and anterior tibial translation were measured between 0 and 90° knee flexion after applying 5 N-m Torque and a 134-N anterior load, respectively. A full kinematics assessment was performed in each following conditions: intact knee, after section of the anterior cruciate ligament (ACL), after section of the ACL and anterolateral ligament (ALL) and Kaplan fibers, after isolated ACLR, after combined ACLR+LET and ACLR+ALLR. ALLR was performed using Gracilis tendon while central strip of the ilio-tibial band was used for the modified Lemaire procedure. These different states were compared using a Tukey paired comparison test. Results: In combined ACL and anterolateral deficient knee, anterior translation and internal rotation remained significantly increased after isolated ACLR compared to intact knee (+2.33 ± 1.44 mm and +1.98 ± 1.06°; p > 0.01). On the other hand, the addition of an ALLR or a modified Lemaire LET to the ACLR allowed to restore anterior translation and internal rotation to values similar to the intact knee. Finally, the two anterolateral procedures had not significantly different values in both tests. This difference was 0.67 ± 1.46 mm for anterior translation (p=0.79) and 0.11 ± 1.11° for internal rotation (p=0.99). Conclusion: In ACL and anterolateral deficient knee, combined ACLR and anterolateral reconstruction allowed restoration of native stability of the knee in anterior translation and internal rotation contrary to isolated ACLR. Additionally, both types of extra-articular reconstruction, ALLR or modified Lemaire procedure, were similar in terms of restoring knee kinematics and neither overconstrained the knee.

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Medial Posterior Capsular Plication Reduces Anterior Shoulder Instability Similar to Remplissage Without Restricting Motion in the Setting of an Engaging Hill-Sachs Defect

The American Journal of Sports Medicine ◽

10.1177/0363546517700860 ◽

2017 ◽

Vol 45 (9) ◽

pp. 1982-1989 ◽

Cited By ~ 6

Author(s):

Brian C. Werner ◽

Xiang Chen ◽

Christopher L. Camp ◽

Andreas Kontaxis ◽

Joshua S. Dines ◽

...

Keyword(s):

Internal Rotation ◽

External Rotation ◽

Biomechanical Testing ◽

Bankart Repair ◽

Anterior Shoulder Instability ◽

Anterior Translation ◽

Capsular Plication ◽

Fresh Frozen ◽

Surgical Options ◽

Joint Loads

Background: Numerous surgical options for the management of engaging Hill-Sachs lesions exist, of which remplissage has emerged as one of the most popular arthroscopic techniques. Remplissage is not without disadvantages, however, and has been demonstrated to potentially result in a loss of external rotation (ER) due to nonanatomic tethering of the infraspinatus tendon and a potential decrease in infraspinatus strength clinically. Purpose: The efficacy of posterior medial capsular plication in addition to Bankart repair was examined as an arthroscopic management strategy for an engaging Hill-Sachs defect. Study Design: Controlled laboratory study. Methods: Eight fresh-frozen human cadaveric shoulders were utilized for the study. After testing baseline translation and motion, 30% Hill-Sachs lesions were created in each specimen. Three experimental groups were assembled: (1) isolated Bankart repair (HSD), (2) Bankart repair with remplissage (RM), and (3) Bankart repair with posterior medial capsular plication (PL). Biomechanical testing was performed to determine anterior translation, range of motion, and Hill-Sachs engagement. Translation and motion measurements were normalized to the baseline laxity values for each specimen. Results: A significant reduction in anterior translation was noted at 60° of abduction and 60° of ER for both the PL and RM groups compared with the HSD group throughout most of the joint loads tested ( P < .05), but no significant differences were noted between the PL and RM groups at any load. The RM group had significantly less normalized ER at 60° of abduction compared with the HSD and PL groups ( P < .05). There were no differences in internal rotation between the groups. All 8 specimens in the HSD group engaged, while no specimens in the RM and PL groups engaged ( P < .001). Conclusion: In a cadaveric model, medial posterior capsular plication as an adjunct to Bankart repair offers similar resistance to anterior translation and Hill-Sachs engagement as compared with remplissage in the setting of an engaging Hill-Sachs defect. Medial posterior capsular plication results in less restriction of ER compared with remplissage without any significant limitation of internal rotation. Clinical Relevance: Posterior medial capsular plication reduces translation and engagement similarly to remplissage, without any restriction in motion.

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Building an accurate 3D model of a circular feature for robot vision

Opto-Electronics Review ◽

10.2478/s11772-012-0017-y ◽

2012 ◽

Vol 20 (2) ◽

Author(s):

L. Li

Keyword(s):

Efficient Method ◽

Error Compensation ◽

3D Model ◽

Robot Vision ◽

Model Analysis ◽

Perspective Projection ◽

Ellipse Fitting ◽

Projection Scheme ◽

Fitting Method ◽

Data Points

AbstractIn this paper, an accurate 3D model analysis of a circular feature is built with error compensation for robot vision. We propose an efficient method of fitting ellipses to data points by minimizing the algebraic distance subject to the constraint that a conic should be an ellipse and solving the ellipse parameters through a direct ellipse fitting method by analysing the 3D geometrical representation in a perspective projection scheme, the 3D position of a circular feature with known radius can be obtained. A set of identical circles, machined on a calibration board whose centres were known, was calibrated with a camera and did the model analysis that our method developed. Experimental results show that our method is more accurate than other methods.

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