Posterior Rotational and Translational Stability in Acromioclavicular Ligament Complex Reconstruction: A Comparative Biomechanical Analysis in Cadaveric Specimens

Background: Persistent posterior instability of the acromioclavicular (AC) joint is a reported complication after isolated coracoclavicular (CC) reconstruction. Thus, multiple techniques have been proposed attempting to restore biomechanics of the AC ligament complex (ACLC). Purpose/Hypothesis: The purpose was to evaluate the posterior translational and rotational stability of an ACLC reconstruction with a dermal allograft (ACLC patch) as compared with 3 suture brace constructs. It was hypothesized that the ACLC patch would better restore AC joint posterior stability. Study Design: Controlled laboratory study. Methods: A total of 28 cadaveric shoulders (mean ± SD age, 57.6 ± 8.3 years) were randomly assigned to 1 of 4 surgical techniques: ACLC patch, oblique brace, anterior brace, and x-frame brace. The force and torque to achieve 10 mm of posterior translation and 20° of posterior rotation of the AC joint were recorded in the following conditions: intact, transected ACLC, ACLC patch/brace repair, ACLC patch/brace repair with dissected CC ligaments, and ACLC patch/brace repair with CC ligament repair. Results: For posterior translation, transection of the ACLC reduced resistance to 16.7% of the native. With the native CC ligaments intact, the ACLC patch (59.1%), oblique brace (54.1%), and anterior brace (60.7%) provided significantly greater stability than the x-frame brace (33.2%; P < .001, P = .008, P < .001, respectively). ACLC patch, oblique brace, and anterior brace continued to have significantly higher posterior translational resistance than the x-frame (35.1%; P < .001, P = .003, P < .001) after transection and subsequent CC ligament repair. For posterior rotation, transection of the ACLC decreased the resistance to 5.4% of the intact state. With the CC ligaments intact, the ACLC patch (77.1%) better restored posterior rotational stability than the oblique (35.3%), anterior (48.5%), and x-frame (23.0%) brace repairs ( P < .001, P = .002, P < .001). CC ligament transection and subsequent repair demonstrated the ACLC patch (41.0%) to have improved stability when compared with the oblique (16.0%), anterior (14.0%), and x-frame (12.7%) repairs ( P = .006, P = .003, P = .002). Conclusion: ACLC reconstruction with a dermal allograft better restored native posterior rotational stability than other brace constructs, with translational stability similar to the oblique and anterior brace technique at the time of surgery. Clinical Relevance: Horizontal stability of the AC joint is primarily controlled by the ACLC. Inability to restore AC joint biomechanics can result in persistent posterior instability and lead to functional impairment.

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Biomechanical evaluation of an independent acromioclavicular ligament repair for acromioclavicular joint reconstruction

Shoulder & Elbow ◽

10.1177/1758573219857685 ◽

2019 ◽

Vol 12 (3) ◽

pp. 184-192

Author(s):

Daniel K Ibrahim ◽

Patrick H Lam ◽

Ricardo J Aveledo Anzola ◽

George AC Murrell

Keyword(s):

Acromioclavicular Joint ◽

Surgical Techniques ◽

Biomechanical Study ◽

Ligament Repair ◽

Suture Bridge ◽

Posterior Translation ◽

Group 3 ◽

Group 2 ◽

Bone Tunnels ◽

Anterior Posterior

Background A number of surgical techniques for the treatment of acromioclavicular joint separations have been described; however, few have been able to create a strong intra-operative construct that provides minimal joint translation. A biomechanical study was conducted to examine joint translation in an independent acromioclavicular ligament repair. Methods Three variations of a novel independent acromioclavicular ligament repair technique underwent testing using a Sawbones model. The technique involves threading sutures through two acromial bone tunnels in a suture-bridge configuration and anchoring them into the distal clavicle. Three groups of eight specimens underwent reconstruction; group 1 using FiberTape, group 2 using FiberWire and group 3 using FiberTape in a modified (under-over) suture-bridge configuration. Superior, anterior and posterior translation was tested at loads of 10, 20 and 30 N. Results Group 3 repair yielded the least translation in both anterior–posterior and superior–inferior planes, with a two-fold decrease in superior translation compared to groups 1 and 2 (P < .05). Both groups 1 and 3 using FiberTape resulted in significantly less anterior and posterior translation compared to the FiberWire group (P < .05). Discussion The independent acromioclavicular ligament repair, without repair of the coracoclavicular ligament, demonstrated significant translational stability in the anterior–posterior and superior–inferior planes.

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Biomechanical Evaluation of Anterolateral Ligament Repair augmented with Internal Brace

The Journal of Knee Surgery ◽

10.1055/s-0041-1726420 ◽

2021 ◽

Author(s):

Ryan P. Roach ◽

David P. Beason ◽

Jonathan S. Slowik ◽

A. Ryves Moore ◽

Ajay C. Lall ◽

...

Keyword(s):

Internal Rotation ◽

Acl Reconstruction ◽

Cruciate Ligament ◽

Surgical Techniques ◽

Anterolateral Ligament ◽

Torsional Stiffness ◽

Rotational Stability ◽

Gap Formation ◽

Internal Brace ◽

Acl Deficient

AbstractInjuries to the anterolateral ligament (ALL) of the knee are commonly associated with anterior cruciate ligament (ACL) ruptures. Biomechanical studies have demonstrated conflicting results with regard to the role of the ALL in limiting tibial internal rotation. Clinically, residual pivot shift following ACL reconstruction has been reported to occur up to 25% and has been correlated with poor outcomes. As such, surgical techniques have been developed to enhance rotational stability. Recent biomechanical studies have demonstrated restoration of internal rotational control following ALL reconstruction. The purpose of our study was to understand the biomechanical effects of ACL reconstruction with an ALL internal brace augmentation. We hypothesized that (1) sectioning of the ALL while preserving other lateral extra-articular structures would lead to significant internal rotation laxity and gap formation and (2) ALL repair with internal brace augmentation would lead to reduction in internal rotation instability and gap formation. In total, 10 fresh-frozen cadaveric knees were thawed and biomechanically tested in internal rotation for 10 cycles of normal physiologic torque in the intact, ACL-deficient, ACL/ALL-deficient, ACL-reconstructed, and ALL-repaired conditions. Each condition was tested at 30, 60, and 90 degrees of flexion. Following the final ALL-repaired condition, specimens were additionally subjected to a final internal rotation to failure at 1 degree at the last-tested degree of flexion. Kinematic measurements of angle and linear gap between the femur and tibia were calculated in addition to torsional stiffness and failure torque. As hypothesized, ALL repair with internal brace augmentation significantly reduced internal rotation angular motion and gap formation at flexion angles greater than 30 degrees. Additionally, ALL sectioning produced nonsignificant increases in internal rotation laxity and gap formation compared with ACL-deficient and ACL-reconstructed states, which did not support our other hypothesis.

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Repair of the entire superior acromioclavicular ligament complex best restores posterior translation and rotational stability

Knee Surgery Sports Traumatology Arthroscopy ◽

10.1007/s00167-018-5205-y ◽

2018 ◽

Vol 27 (12) ◽

pp. 3764-3770 ◽

Cited By ~ 13

Author(s):

Daichi Morikawa ◽

Felix Dyrna ◽

Mark P. Cote ◽

Jeremiah D. Johnson ◽

Elifho Obopilwe ◽

...

Keyword(s):

Rotational Stability ◽

Posterior Translation

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A Systematic Survey of the Realm of Biomechanics

Design, Development, and Optimization of Bio-Mechatronic Engineering Products - Advances in Mechatronics and Mechanical Engineering ◽

10.4018/978-1-5225-8235-9.ch001 ◽

2019 ◽

pp. 1-35

Author(s):

Deepak Mahapatra ◽

Shubhankar Bhowmick ◽

Shubhashis Sanyal

Keyword(s):

Human Motion ◽

Biomechanical Analysis ◽

Spine Biomechanics ◽

Systematic Survey ◽

Joint Biomechanics ◽

Functional Knowledge ◽

Arteries And Veins ◽

Made In

The area of biomechanics is challenging and broad as it involves multidisciplinary concepts of engineering together with functional knowledge of biosciences. The area is rapidly evolving and new additions to it are being made daily. A survey that may help a beginner to have a general look on the broader aspects of the sub-domains of biomechanics is not available. The chapter aims to overview the realm of biomechanics and provide an introduction to various areas with mention to researches carried out. A broad survey of various areas of biomechanics from a mechanical engineer's perspective is reported in this chapter. Prominent areas like biomechanics of human motion; bone and joint biomechanics; biomechanics of spine; biomechanics of head, shoulder, and muscles; biomechanical analysis of heart and lungs; biomechanical analysis of arteries and veins; and MEMS in biomechanics are explored. Though it is difficult to include all the developments relevant to the above areas, the authors have focused primarily on a few prominent studies made in the last two decades in various domains.

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Posteromedial Ligament Repair of the Knee With Suture Tape Augmentation: A Biomechanical Study

The American Journal of Sports Medicine ◽

10.1177/0363546519868961 ◽

2019 ◽

Vol 47 (12) ◽

pp. 2952-2959 ◽

Cited By ~ 5

Author(s):

Julian T. Mehl ◽

Cameron Kia ◽

Matthew Murphy ◽

Elifho Obopilwe ◽

Mark Cote ◽

...

Keyword(s):

Internal Rotation ◽

Knee Flexion ◽

Primary Repair ◽

Cruciate Ligament ◽

Surgical Techniques ◽

Ligament Repair ◽

Acl Injuries ◽

Tendon Reconstruction ◽

Reasonable Alternative ◽

Suture Tape

Background: In cases of acute combined posteromedial and anterior cruciate ligament (ACL) injuries, primary repair of the superficial medial collateral ligament (sMCL) and posterior oblique ligament (POL) with suture tape augmentation may be a reasonable alternative to standard tendon reconstruction techniques. Purpose/Hypothesis: The purpose was to examine the rotational and valgus laxity with ACL strain following sMCL and POL repair with suture tape augmentation at various degrees of knee flexion. It was hypothesized that this technique would restore knee laxity and kinematics comparable with those of the intact state. Study Design: Controlled laboratory study. Methods: Ten cadaveric knee specimens (mean ± SD, 57.9 ± 5.9 years) were obtained. Specimens were tested with the tibia fixed and the femur mobile on an X-Y table. Each specimen was tested in 4 conditions according to the state of the sMCL and POL: native, deficient, repaired with suture tape augmentation, and reconstructed with tendon allografts. Valgus laxity was tested with 40-N force applied in the lateral direction of the femur, and rotational motion was tested with 5-N torque applied to the tibia. ACL strain during valgus stress was also measured. Each condition was tested in 0°, 15°, 30°, 45°, and 60° of knee flexion. Results: Dissection of the sMCL and POL led to significantly increased valgus laxity in all flexion angles, with a significant increase in ACL strain at 30° ( P < .001) and 45° ( P < .001). Ligament repair with suture tape augmentation demonstrated similar valgus and rotational laxity as compared with intact specimens, with the exception of increased internal rotation at 30° ( P = .005). Ligament reconstruction resulted in significantly increased valgus opening at 45° ( P = .048) and significantly increased internal rotation at 30° ( P < .001) as compared with the native state. Direct comparison between surgical techniques showed no significant differences. Conclusion: At time zero, ligament repair of the posteromedial knee with suture tape augmentation restored close-to-native valgus and rotatory laxity, as well as native ACL strain for cases of complete sMCL and POL avulsion. Clinical Relevance: Ligament repair of the sMCL and POL with suture tape augmentation may be a reasonable alternative to tendon reconstruction techniques in cases of acute combined posteromedial and ACL injuries with valgus and rotatory instability.

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The Integrity of the Acromioclavicular Capsule Ensures Physiological Centering of the Acromioclavicular Joint Under Rotational Loading

The American Journal of Sports Medicine ◽

10.1177/0363546518758287 ◽

2018 ◽

Vol 46 (6) ◽

pp. 1432-1440 ◽

Cited By ~ 22

Author(s):

Felix G.E. Dyrna ◽

Florian B. Imhoff ◽

Andreas Voss ◽

Sepp Braun ◽

Elifho Obopilwe ◽

...

Keyword(s):

Translational Motion ◽

Measuring System ◽

Resistance Force ◽

Materials Testing ◽

Detailed Knowledge ◽

Native State ◽

Ac Joint ◽

Axial Forces ◽

Resistance Torque ◽

Posterior Translation

Background: The acromioclavicular (AC) capsule is an important stabilizer against horizontal translation and also contributes to the strut function of the clavicle, which guides rotation of the scapula. To best reproduce the biomechanical properties and the complex 3-dimensional (3D) guidance of the AC joint, detailed knowledge of the contribution of each of the distinctive capsular structures is needed. Purpose/Hypothesis: To perform a detailed biomechanical evaluation of the specific capsular structures of the AC joint and their contribution to translational and rotational stability. The hypothesis was that successive cutting of each quadrant of the AC capsule would result in increased instability and increased amplitude of the clavicle’s motion in relation to the acromion. Study Design: Controlled laboratory study. Methods: Thirty-two fresh-frozen human cadaveric shoulders were used. Each scapula was fixed to a swivel fixture of a servohydraulic materials testing system. The AC capsule was dissected in serial steps with immediate rotational and horizontal testing after each cut. A 3D optical measuring system was used to evaluate 3D movement. Posterior translation, rotation, and displacement of the lateral clavicle in relation to the center of rotation were measured. Torques and axial forces required to rotate and translate the clavicle were recorded. Results: When posterior translational force was applied, all specimens with a completely cut AC capsule demonstrated a significant loss of resistance force against the translational motion when compared with the native state ( P < .05). The resistance force against posterior translation was reduced to less than 27% of the native state for all specimens. Sequential cutting of the AC capsule resulted in a significant reduction of resistance torque against anterior rotation for all specimens with less than 22% of resistance force compared with the native state. Cutting 50% of the capsule reduced the resistance torque for all segments and all testing modalities (posterior translation as well as anterior and posterior rotation) significantly compared with the native state ( P < .05). Cutting the entire AC capsule resulted in a significant increase in motion within the joint as a sign of decentering of the AC joint when torque was applied. All groups demonstrated a significant increase of motion in all directions when the AC capsule was cut by 50%. Conclusion: Cutting the entire capsule (with intact coracoclavicular [CC] ligaments) reduced the resistance force to less than 25% compared with the native state during translational testing and less than 10% compared with the native state during rotational testing. However, the anterior segments of the capsule provided the greatest stability under rotational loading. Second, the amplitude of the joint’s motion significantly increased under rotational stress, indicating increased amplitude of the clavicle’s motion in relation to the acromion when the ligamentous structures of the AC capsule are dissected. Clinical Relevance: To best restore stability to the AC joint, the relevance and function of each section of the circumferential AC capsule need to be understood. Our findings support the synergistic contribution of the CC ligaments and AC capsular structures to AC joint stability. This synergy supports the need to address both structures to achieve anatomic reconstruction.

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The Infinity-Lock System for Chronic Grade III AC Joint Dislocation: A Novel Technique, Rehabilitation Protocol and Short Term Results

Journal of Clinical Medicine ◽

10.3390/jcm9082519 ◽

2020 ◽

Vol 9 (8) ◽

pp. 2519

Author(s):

Alfonso Maria Romano ◽

Pasquale Casillo ◽

Monica De Simone ◽

Guglielmo Nastrucci ◽

Donatella Risorto ◽

...

Keyword(s):

Constant Score ◽

Surgical Techniques ◽

Nonoperative Treatment ◽

Modified Technique ◽

Ac Joint ◽

Joint Dislocation ◽

Ac Joint Dislocation ◽

Choice Of Treatment ◽

Grade Iii

Background: the choice of treatment of chronic grade III acromioclavicular (AC) joint dislocation is controversial. Several surgical techniques have been described in the literature, responding differently to nonoperative treatment. The aim of this study is to describe a modified technique of stabilizing an AC joint dislocation with the new Infinity-Lock Button System, in order to demonstrate that it is effective in optimizing outcomes and decreasing complications. Methods: this is a retrospective study of 15 patients who underwent surgical stabilization of the AC joint dislocation between 2018 and 2019, through modified surgical technique using the Infinity-Lock Button System. Active range of motion (ROM), Specific Acromio Clavicular Score (SACS) and Constant Score (CS) were evaluated preoperatively and postoperatively at last 18 months follow up. Patients rated their outcomes as very good, good, satisfactory, or unsatisfactory. Results: a total of twelve patients rated their outcome as very good and three as good; no patients were dissatisfied with surgery. The mean Constant Score increased from 38 points preoperatively to 95 postoperatively, the average SACS score decreased from 52 points preoperatively to 10 postoperatively, both significantly. No complications were detected. Conclusion: the described technique is effective for treatment of chronic grade III AC joint dislocation, resulting in elevated satisfaction ratings and predictable outcomes. Nevertheless, further longer term follow-up studies are required.

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Biomechanical Analysis of Glenohumeral Internal Rotation Deficit in a Cadaveric Model

ASME 2010 5th Frontiers in Biomedical Devices Conference and Exhibition ◽

10.1115/biomed2010-32052 ◽

2010 ◽

Author(s):

Akash Gupta ◽

Jeffrey Gates ◽

Michelle H. McGarry ◽

James E. Tibone ◽

Thay Q. Lee

Keyword(s):

Internal Rotation ◽

Clinical Decision Making ◽

Glenohumeral Joint ◽

External Rotation ◽

Clinical Decision ◽

Biomechanical Analysis ◽

Glenohumeral Internal Rotation Deficit ◽

Posterior Translation ◽

Throwers Shoulder ◽

Cadaveric Model

Overhead throwing athletes have been shown to develop adaptive changes in humeral rotation to allow for higher throwing velocities. This manifests as an increase in humeral external rotation and a decrease in internal rotation, which is called glenohumeral internal rotation deficit (GIRD). The percentage of GIRD that significantly affects glenohumeral joint kinematics is not known. The objective of the study was to create a throwers shoulder model with fixed percentages of GIRD to determine at which point kinematic changes start occurring. The results showed that there was a significant decrease in posterior translation starting at 10% GIRD. With inferior translational loads, significantly less inferior translation starts occurring at 20% GIRD. The humeral head apex position at maximum external rotation moves superiorly, posteriorly and laterally, with significant changes in the superior direction occurring with 10% GIRD onwards. Overall, significant kinematic changes begin at 10% GIRD and this should be taken into account for clinical decision-making as to when intervention is necessary.

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A biomechanical analysis of tibial ACL reconstruction with graft length mismatch

Journal of Orthopaedic Surgery ◽

10.1177/2309499017690983 ◽

2017 ◽

Vol 25 (1) ◽

pp. 230949901769098

Author(s):

Evan B Gaines ◽

Diana Lau ◽

Qais Naziri ◽

Westley Hayes ◽

Julio J. Jauregui ◽

...

Keyword(s):

Cyclic Loading ◽

Acl Reconstruction ◽

Surgical Techniques ◽

The Other ◽

Biomechanical Analysis ◽

Graft Fixation ◽

Bptb Graft ◽

Load To Failure ◽

Group 3 ◽

Graft Length

Introduction: The incidence of graft length mismatch (GLM) during anterior cruciate ligament (ACL) reconstruction is reported to be up to 13%, with a rate of 20% when using bone-patellar tendon-bone (BPTB) allografts. Multiple techniques have been described to accommodate for the longer BPTB graft. As no study has compared the biomechanical properties of these methods (with cyclic loading), we evaluated the strength of four different surgical techniques used to accommodate for GLM during ACL reconstruction. Methods: A total of 32 fresh-frozen bovine tibiae and patellar tendons were divided into four groups based on the method of tibial graft fixation: (1) sutures tied over a post, (2) bone staples, (3) screws and washers, and (4) soft-tissue conversion with interference screw. Biomechanical testing was performed comparing the tensile properties of graft fixation techniques under cyclic loading. Ability to withstand 1500 cycles of load, the maximum tensile strength at load-to-failure, and the mode-of-failure were evaluated. Results: Only group 4 had all grafts intact after 1500 loading cycles, while the other groups had one graft failure at 338 (group 1), 240 (group 2), and 309 (group 3) cycles. The highest mean load-to-failure was observed in group 3 at 762 ± 173 N, which was found to be significantly higher than the other groups. The mean loads to failure in groups 1–4 were 453 ± 86 N, 485 ± 246 N, 762 ± 173 N, and 458 ± 128 N. Conclusion: While there are multiple viable techniques for fixation of a BPTB graft in the case of GLM, this study demonstrated that direct screw fixation offers the strongest construct.

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