scholarly journals A Novel In Vivo Joint Loading System to Investigate the Effect of Daily Mechanical Load on a Healing Anterior Cruciate Ligament Reconstruction

2010 ◽  
Vol 4 (1) ◽  
Author(s):  
Mark Stasiak M. Eng ◽  
Carl Imhauser ◽  
Jonathan Packer ◽  
Asheesh Bedi ◽  
Robert Brophy ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Knee Joint ◽  
Bone Healing ◽  
Structural Changes ◽  
Mechanical Load ◽  
Tracking System ◽  
Cruciate Ligament ◽  
Healing Process ◽  
Anterior Cruciate

We designed and validated a novel knee joint fixation/distraction system to study tendon–to-bone healing in an in vivo rat model of anterior cruciate ligament (ACL) reconstruction. The system uses an external fixator to apply a cyclic distraction of the knee joint while monitoring the resultant force developed across the joint, thus providing a temporal indication of structural changes during the healing process of the bone-tendon-bone reconstruction. The validation was performed using an optical kinematic tracking system to determine the local displacement of the knee. The average system compliance was determined to be 42.4±8.8 μm/N with a coefficient of variation of 20.7%. The compliance was used to obtain a best fit correction factor which brought the total root mean square error of knee joint distraction to within 179 μm (16.1%) of the applied distraction. We performed a pilot study using 15 rats that had ACL reconstructions using a flexor digitorum longus tendon autograft and found that the animals tolerated the indwelling fixator and daily anesthesia over a 10 day loading protocol. Our knee joint fixation/distraction system provides a valuable tool to study how mechanical stimuli affect in vivo bone-tendon-bone healing.

A Novel Joint Loading System to Investigate the Effect of Daily Mechanical Load on a Healing Anterior Cruciate Ligament (ACL) Reconstruction

2009 ◽  
Author(s):  
Mark Stasiak ◽  
Peter Torzilli ◽  
Carl Imhauser ◽  
Jonathan Packer ◽  
Asheesh Bedi ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Knee Joint ◽  
Acl Reconstruction ◽  
Rat Model ◽  
Mechanical Load ◽  
Cruciate Ligament ◽  
Joint Distraction ◽  
The Us ◽  
Loading System ◽  
Anterior Cruciate

A novel system was developed to investigate the effect of mechanical load on tendon to bone healing, using a rat model of ACL reconstruction. A greater understanding of the effects of mechanical load may improve rehabilitation practices for the more than 100,000 ACL reconstructions each year in the US alone.[1] The purpose of this study was to assess: the accuracy of knee joint distraction, variability in fixator compliance, and ability of animals to tolerate the fixator over a typical loading protocol.

Bioactive Tape With BMP-2 Binding Peptides Captures Endogenous Growth Factors and Accelerates Healing After Anterior Cruciate Ligament Reconstruction

2018 ◽  
Vol 46 (12) ◽  
pp. 2905-2914 ◽  
Author(s):  
João F. Crispim ◽  
Sai C. Fu ◽  
Yuk W. Lee ◽  
Hugo A.M. Fernandes ◽  
Pascal Jonkheijm ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Growth Factors ◽  
Acl Reconstruction ◽  
Cruciate Ligament ◽  
Healing Process ◽  
Enzyme Linked Immunosorbent Assay ◽  
In Vivo Experiments ◽  
Binding Peptides ◽  
Anterior Cruciate

Background: The anterior cruciate ligament (ACL) has poor regenerative capacity, and an injury leads to loss of function, limiting quality of life and increasing the incidence of osteoarthritis. Surgical interventions can stabilize the joint and improve functional recovery. The delivery of growth factors (GFs) enhances the healing process; however, this is complex in its regulation, is high in costs, has side effects, and can only be accomplished with supraphysiological concentrations and thus is currently not clinically feasible. However, the immobilization of a patient’s endogenous GFs in biomaterials can overcome these problems. Purpose: To develop a method to capture endogenous bone morphogenetic protein–2 (BMP-2) and ultimately show enhanced ACL healing in vivo using this novel methodology. Study Design: Controlled laboratory study. Methods: BMP-2 binding peptides were synthetized, purified, and immobilized on polycaprolactone (PCL) films. The affinity between the peptide and human BMP-2 (hBMP-2) was confirmed with immunofluorescence and enzyme-linked immunosorbent assay. The C2C12 Luc reporter cell line was used to confirm the bioactivity of immobilized BMP-2. For in vivo experiments, the same functionalization technology was applied to the commercially available Polytape, and the functionalized tape was sutured together with the graft used for ACL reconstruction in rats. Each animal underwent reconstruction with either native Polytape (n = 3) or Polytape with BMP-2 binding peptides (n = 3). At 2 and 6 weeks after surgery, the graft was assessed by histology and micro–computed tomography. Results: The covalent immobilization of the peptide in PCL was successful, allowing the peptide to capture hBMP-2, which remained bioactive and led to the osteogenic differentiation of C2C12. In vivo experiments confirmed the potential of the Polytape functionalized with the BMP-2 binding peptide to capture endogenous BMP-2, leading to enhanced bone formation inside the femoral and tibial tunnels and ultimately improving the graft’s quality. Conclusion: The incorporation of BMP-2 binding peptides into materials used for ACL reconstruction can capture endogenous hBMP-2, which enhances the healing process inside the bone tunnels. Clinical Relevance: These results demonstrate the potential of using synthetic peptides to endow biomaterials with novel biological functions, namely to capture and immobilize endogenous GFs.

scholarly journals Reconsidering Reciprocal Length Patterns of the Anteromedial and Posterolateral Bundles of the Anterior Cruciate Ligament During In Vivo Gait

2020 ◽  
Vol 48 (8) ◽  
pp. 1893-1899 ◽  
Author(s):  
Zoë A. Englander ◽  
Jocelyn R. Wittstein ◽  
Adam P. Goode ◽  
William E. Garrett ◽  
Louis E. DeFrate
Keyword(s):  
Anterior Cruciate Ligament ◽  
Knee Joint ◽  
Cruciate Ligament ◽  
Functional Anatomy ◽  
Attachment Site ◽  
Attachment Sites ◽  
Biplanar Radiographs ◽  
Anterior Cruciate ◽  
The Right

Background: Some cadaveric studies have indicated that the anterior cruciate ligament (ACL) consists of anteromedial and posterolateral bundles that display reciprocal function with regard to knee flexion. However, several in vivo imaging studies have suggested that these bundles elongate in parallel with regard to flexion. Furthermore, the most appropriate description of the functional anatomy of the ACL is still debated, with the ACL being described as consisting of 2 or 3 bundles or as a continuum of fibers. Hypothesis: As long as their origination and termination locations are defined within the ACL attachment site footprints, ACL bundles elongate in parallel with knee extension during gait. Study Design: Descriptive laboratory study. Methods: High-speed biplanar radiographs of the right knee joint were obtained during gait in 6 healthy male participants (mean ± SD: body mass index, 25.5 ± 1.2 kg/m2; age, 29.2 ± 3.8 years) with no history of lower extremity injury or surgery. Three-dimensional models of the right femur, tibia, and ACL attachment sites were created from magnetic resonance images. The bone models were registered to the biplanar radiographs, thereby reproducing the in vivo positions of the knee joint. For each knee position, the distances between the centroids of the ACL attachment sites were used to represent ACL length. The lengths of 1000 virtual bundles were measured for each participant by randomly sampling locations on the attachment site surfaces and measuring the distances between each pair of locations. Spearman rho rank correlations were performed between the virtual bundle lengths and ACL length. Results: The virtual bundle lengths were highly correlated with the length of the ACL, defined as the distance between the centroids of the attachment sites (rho = 0.91 ± 0.1, across participants; P < 5 × 10-5). The lengths of the bundles that originated and terminated in the anterior and medial aspects of the ACL were positively correlated (rho = 0.81 ± 0.1; P < 5 × 10-5) with the lengths of the bundles that originated and terminated in the posterior and lateral aspects of the ACL. Conclusion: As long as their origination and termination points are specified within the footprint of the attachment sites, ACL bundles elongate in parallel as the knee is extended. Clinical Relevance: These data elucidate ACL functional anatomy and may help guide ACL reconstruction techniques.

scholarly journals Predictions of Anterior Cruciate Ligament Dynamics From Subject-Specific Musculoskeletal Models and Dynamic Biplane Radiography

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
James P. Charles ◽  
Freddie H. Fu ◽  
William J. Anderst
Keyword(s):  
Anterior Cruciate Ligament ◽  
Knee Joint ◽  
Cruciate Ligament ◽  
Knee Ligament ◽  
Functional Activities ◽  
Musculoskeletal Models ◽  
Subject Specific ◽  
Force Peak ◽  
Anterior Cruciate

Abstract In vivo knee ligament forces are important to consider for informing rehabilitation or clinical interventions. However, they are difficult to directly measure during functional activities. Musculoskeletal models and simulations have become the primary methods by which to estimate in vivo ligament loading. Previous estimates of anterior cruciate ligament (ACL) forces range widely, suggesting that individualized anatomy may have an impact on these predictions. Using ten subject-specific (SS) lower limb musculoskeletal models, which include individualized musculoskeletal geometry, muscle architecture, and six degree-of-freedom knee joint kinematics from dynamic biplane radiography (DBR), this study provides SS estimates of ACL force (anteromedial-aACL; and posterolateral-pACL bundles) during the full gait cycle of treadmill walking. These forces are compared to estimates from scaled-generic (SG) musculoskeletal models to assess the effect of musculoskeletal knee joint anatomy on predicted forces and the benefit of SS modeling in this context. On average, the SS models demonstrated a double force peak during stance (0.39–0.43 xBW per bundle), while only a single force peak during stance was observed in the SG aACL. No significant differences were observed between continuous SG and SS ACL forces; however, root mean-squared differences between SS and SG predictions ranged from 0.08 xBW to 0.27 xBW, suggesting SG models do not reliably reflect forces predicted by SS models. Force predictions were also found to be highly sensitive to ligament resting length, with ±10% variations resulting in force differences of up to 84%. Overall, this study demonstrates the sensitivity of ACL force predictions to SS anatomy, specifically musculoskeletal joint geometry and ligament resting lengths, as well as the feasibility for generating SS musculoskeletal models for a group of subjects to predict in vivo tissue loading during functional activities.

The Analysis of Proprioception Alteration during First Five Months after Anterior Cruciate Ligament Reconstruction

2018 ◽  
Vol 1 (84) ◽  
Author(s):  
Vilma Jurevičienė ◽  
Albertas Skurvydas ◽  
Juozas Belickas ◽  
Giedra Bušmanienė ◽  
Dovilė Kielė ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Angular Velocity ◽  
Knee Joint ◽  
Cruciate Ligament ◽  
Position Sense ◽  
Joint Position Sense ◽  
Joint Position ◽  
Starting Position ◽  
Angular Velocities ◽  
Anterior Cruciate

Research  background  and  hypothesis.  Proprioception  is  important  in  the  prevention  of  injuries  as  reduced proprioception  is  one  of  the  factors  contributing  to  injury  in  the  knee  joint,  particularly  the  ACL.  Therefore, proprioception appears not only important for the prevention of ACL injuries, but also for regaining full function after ACL reconstruction.Research aim. The aim of this study was to understand how proprioception is recovered four and five months after anterior cruciate ligament (ACL) reconstruction.Research methods. The study included 15 male subjects (age – 33.7 ± 2.49 years) who had undergone unilateral ACL reconstruction with a semitendinosus/gracilis (STG) graft in Kaunas Clinical Hospital. For proprioceptive assessment, joint position sense (JPS) was measured on both legs using an isokinetic dynamometer (Biodex), at knee flexion of 60° and 70°, and at different knee angular velocities of 2°/s and 10°/s. The patients were assessed preoperatively and after 4 and 5 months, postoperatively.Research results. Our study has shown that the JPS’s (joint position sense) error scores  to a controlled active movement is significantly higher in injured ACL-deficient knee than in the contralateral knee (normal knee) before surgery and after four and five months of rehabilitation.  After 4 and 5 months of rehabilitation we found significantly lower values in injured knees compared to the preoperative data. Our study has shown that in injured knee active angle reproduction errors after 4 and 5 months of rehabilitation were higher compared with the ones of the uninjured knee. Proprioceptive ability on the both legs was  independent of all differences angles for target and starting position for movement. The knee joint position sense on both legs depends upon the rate of two different angular velocities and the mean active angle reproduction errors at the test of angular velocity slow speed was the highest compared with the fast angular velocity. Discussion and conclusions. In conclusion, our study shows that there was improvement in mean JPS 4 and 5 months after ACL reconstruction, but it did not return to normal indices.Keywords: knee joint, joint position sense, angular velocity, starting position for movement.

Measuring Strain Distributions in the Anterior Cruciate Ligament Using Ultrasound

2010 ◽  
Author(s):  
Amy Cochran ◽  
Yingxin Gao ◽  
Ursula Krotscheck ◽  
Margret Thompson ◽  
James Stouffer ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Cruciate Ligament ◽  
Treatment Strategies ◽  
Acl Injury ◽  
Physiological Factors ◽  
Detailed Understanding ◽  
Prevention And Treatment ◽  
Anterior Cruciate ◽  
Tissue Motion

Optimal prevention and treatment strategies of anterior cruciate ligament (ACL) injury can be realized with a detailed understanding of how physiological factors impact the ACL. A noninvasive, in vivo method that assesses the ACL’s mechanical integrity is needed to help clarify this multi-factorial pathophysiology. We investigated the use of the noninvasive, in vivo technique, ultrasound strain elastography (USE) (1), to distinguish between normal and injured ACLs. USE is used as a diagnostic tool in oncological (2), hepatic (3), and cardiovascular (4) applications. This technique uses ultrasonic RF data to track tissue motion in order to estimate strain within the tissue.

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