A Preclinical Model to Study the Influence of Graft Force on the Healing of the Anterior Cruciate Ligament Graft

2018 ◽  
Vol 32 (05) ◽  
pp. 441-447
Author(s):  
Richard Ma ◽  
Mark Stasiak ◽  
Xiang-Hua Deng ◽  
Scott Rodeo
Keyword(s):  
Anterior Cruciate Ligament ◽  
Acl Reconstruction ◽  
Knee Flexion ◽  
Cruciate Ligament ◽  
Tunnel Position ◽  
Anterior Cruciate Ligament Graft ◽  
Acl Graft ◽  
Anterior Cruciate ◽  
Femoral Graft

AbstractThe purpose of this study is to establish a small animal anterior cruciate ligament (ACL) reconstruction research model where ACL graft force can be varied to create different graft force patterns with controlled knee motion. Cadaveric (n = 10) and in vivo (n = 10) rat knees underwent ACL resection followed by reconstruction using a soft tissue autograft. Five cadaveric and five in vivo knees received a nonisometric, high-force femoral graft tunnel position. Five cadaveric and five in vivo knees received a more isometric, low-force graft tunnel position. ACL graft force (N) was then recorded as the knee was ranged from extension to 90 degrees using a custom knee flexion device. Our results demonstrate that distinct ACL graft force patterns were generated for the high-force and low-force femoral graft tunnels. For high-force ACL grafts, ACL graft forces increased as the knee was flexed both in cadaveric and in vivo knees. At 90 degrees of knee flexion, high-force ACL grafts had significantly greater mean graft force when compared with baseline (cadaver: 7.76 ± 0.54 N at 90 degrees vs. 4.94 ± 0.14 N at 0 degree, p = 0.004; in vivo: 7.29 ± 0.42 N at 90 degrees vs. 4.74 ± 0.13 N at 0 degree, p = 0.007). In contrast, the graft forces for low-force ACL grafts did not change with knee flexion (cadaver: 4.94 ± 0.11 N at 90 degrees vs. 4.72 ± 0.14 N at 0 degree, p = 0.41; in vivo: 4.78 ± 0.26 N at 90 degrees vs. 4.77 ± 0.06 N at 0 degree, p = 1). Compared with nonisometric ACL grafts, the graft force for grafts placed in an isometric position had significantly lower ACL graft forces at 15, 30, 45, 60, 70, and 90 degrees in both cadaveric and in vivo knees. In conclusion, we have developed a novel ACL reconstruction model that can reproducibly produce two ACL graft force patterns. This model would permit further research on how ACL graft forces may affect subsequent graft healing, maturation, and function.

The Contribution of Partial Meniscectomy to Preoperative Laxity and Laxity After Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction: In Vivo Kinematics With Navigation

2019 ◽  
Vol 47 (13) ◽  
pp. 3203-3211
Author(s):  
Alberto Grassi ◽  
Stefano Di Paolo ◽  
Gian Andrea Lucidi ◽  
Luca Macchiarola ◽  
Federico Raggi ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Acl Reconstruction ◽  
Knee Flexion ◽  
Cruciate Ligament ◽  
Single Bundle ◽  
Anatomic Acl Reconstruction ◽  
Medial Meniscectomy ◽  
Lateral Meniscectomy ◽  
Anterior Cruciate

Background: Limited in vivo kinematic information exists on the effect of clinical-based partial medial and lateral meniscectomy in the context of anterior cruciate ligament (ACL) reconstruction. Hypothesis: In patients with ACL deficiency, partial medial meniscus removal increases the anteroposterior (AP) laxity with compared with those with intact menisci, while partial lateral meniscus removal increases dynamic laxity. In addition, greater postoperative laxity would be identified in patients with partial medial meniscectomy. Study design: Cross-sectional study; Level of evidence, 3. Methods: A total of 164 patients with ACL tears were included in the present study and divided into 4 groups according to the meniscus treatment they underwent: patients with partial lateral meniscectomy (LM group), patients with partial medial meniscectomy (MM group), patients with partial medial and lateral meniscectomy (MLM group), and patients with intact menisci who did not undergo any meniscus treatment (IM group). A further division in 2 new homogeneous groups was made based on the surgical technique: 46 had an isolated single-bundle anatomic ACL reconstruction (ACL group), while 13 underwent a combined single-bundle anatomic ACL reconstruction and partial medial meniscectomy (MM-ACL group). Standard clinical laxities (AP translation at 30° of knee flexion, AP translation at 90° of knee flexion) and pivot-shift (PS) tests were quantified before and after surgery by means of a surgical navigation system dedicated to kinematic assessment. The PS test was quantified through 3 different parameters: the anterior displacement of the lateral tibial compartment (lateral AP); the posterior acceleration of the lateral AP during tibial reduction (posterior acceleration); and finally, the area included by the lateral AP translation with respect to the flexion/extension angle (area). Results: In the ACL-deficient status, the MM group showed a significantly greater tibial translation compared with the IM group ( P < .0001 for AP displacement at 30° [AP30] and 90° [AP90] of flexion) and the LM group ( P = .002 for AP30 and P < .0001 for AP90). In the PS test, the area of LM group was significantly larger (57%; P = .0175) than the one of the IM group. After ACL reconstruction, AP translation at 30° was restored, while the AP90 remained significantly greater at 1.3 mm ( P = .0262) in the MM-ACL group compared with those with intact menisci. Conclusion: Before ACL reconstruction, partial medial meniscectomy increased AP laxity at 30° and 90° and lateral meniscectomy increased dynamic PS laxity with respect to intact menisci. Anatomic single-bundle ACL reconstruction decreased laxities, but a residual anterior translation of 1.3 mm at 90° remained in patients with partial medial meniscectomy, with respect to those with intact menisci.

The Elongation Behavior of the Anterior Cruciate Ligament Graft in Vivo

2001 ◽  
Vol 29 (2) ◽  
pp. 161-166 ◽  
Author(s):  
Bruce D. Beynnon ◽  
Benjamin S. Uh ◽  
Robert J. Johnson ◽  
Braden C. Fleming ◽  
Per A. Renström ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Cruciate Ligament ◽  
Anterior Cruciate Ligament Graft ◽  
Anterior Cruciate

Effect of Dynamic Changes in Anterior Cruciate Ligament In Situ Graft Force on the Biological Healing Response of the Graft-Tunnel Interface

2018 ◽  
Vol 46 (4) ◽  
pp. 915-923 ◽  
Author(s):  
Richard Ma ◽  
Michael Schär ◽  
Tina Chen ◽  
Marco Sisto ◽  
Joseph Nguyen ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Acl Reconstruction ◽  
Cruciate Ligament ◽  
Male Rats ◽  
Joint Motion ◽  
Dynamic Changes ◽  
Knee Motion ◽  
Acl Graft ◽  
Anterior Cruciate

Background: Anterior cruciate ligament (ACL) grafts that are placed for reconstruction are subject to complex forces. Current “anatomic” ACL reconstruction techniques may result in greater in situ graft forces. The biological effect of changing magnitudes of ACL graft force on graft-tunnel osseointegration is not well understood. Purpose: The research objective is to determine how mechanical force on the ACL graft during knee motion affects tendon healing in the tunnel. Study Design: Controlled laboratory study. Methods: Male rats (N = 120) underwent unilateral ACL reconstruction with a soft tissue flexor tendon autograft. ACL graft force was modulated by different femoral tunnel positions at the time of surgery to create different graft force patterns with knee motion. External fixators were used to eliminate graft load during cage activity. A custom knee flexion device was used to deliver graft load through controlled daily knee motion. Graft-tunnel healing was then assessed via biomechanical, micro–computed tomography, and histological analyses. Results: ACL graft-tunnel healing was sensitive to dynamic changes in graft forces with postoperative knee motion. High ACL graft force with joint motion resulted in early inferior ACL graft load to failure as compared with knees that had low-force ACL grafts and joint motion and knees that were immobilized (mean ± SD: 5.50 ± 2.30 N vs 9.91 ± 3.54 N [ P = .013] and 10.90 ± 2.8 N [ P = .001], respectively). Greater femoral bone volume fraction was seen in immobilized knees and knees with low-force ACL grafts when compared with high-force ACL grafts at 3 and 6 weeks. Conclusion: The authors were able to demonstrate that ACL graft-tunnel incorporation is sensitive to dynamic changes in ACL graft force with joint motion. Early high forces on the ACL graft appear to impair graft-tunnel osseointegration. Clinical Relevance: Current “anatomic” techniques of ACL reconstruction may result in greater graft excursion and force with knee motion. Our results suggest that the postoperative rehabilitation regimen may need to be modified during the early phase of healing to protect the reconstruction.

The in Vivo Kinematics of the Anteromedial and Posterolateral Bundles of the Anterior Cruciate Ligament during Weightbearing Knee Flexion

2007 ◽  
Vol 35 (4) ◽  
pp. 547-554 ◽  
Author(s):  
Susan S. Jordan ◽  
Louis E. DeFrate ◽  
Kyung Wook Nha ◽  
Ramprasad Papannagari ◽  
Thomas J. Gill ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Knee Flexion ◽  
Cruciate Ligament ◽  
In Vivo Kinematics ◽  
Anterior Cruciate

Static and Fatigue Strength of a Fixation Device Transducer for Measuring Anterior Cruciate Ligament Graft Tension

2000 ◽  
Vol 122 (6) ◽  
pp. 600-603 ◽  
Author(s):  
Isaac Zacharias ◽  
M. L. Hull ◽  
Stephen M. Howell
Keyword(s):  
Anterior Cruciate Ligament ◽  
Fatigue Strength ◽  
Cruciate Ligament ◽  
Fixation Device ◽  
Structural Failure ◽  
Femoral Fixation ◽  
Anterior Cruciate Ligament Graft ◽  
Scale Error ◽  
Anterior Cruciate

To determine which exercises do not overload the graft-fixation complex during intensive rehabilitation from reconstructive surgery of the anterior cruciate ligament (ACL), it would be useful to measure ACL graft loads during rehabilitative activities in vivo in humans. A previous paper by Ventura et al. (1998) reported on the design of an implantable transducer integrated into a femoral fixation device and demonstrated that the transducer could be calibrated to measure graft loads to better than 10 percent full-scale error in cadaveric knees. By measuring both the static and fatigue strengths of the transducer, the purpose of the present study was to determine whether the transducer could be safely implanted in humans without risk of structural failure. Eight devices were loaded to failure statically. Additionally, seven devices were tested using the up-and-down method to estimate the median fatigue strength at a life of 225,000 cycles. The average ultimate strength was 1856±74 N and the median fatigue strength was 441 N at a life of 225,000 cycles. The maximum graft load during normal daily activities is estimated to be 500 N and the 225,000 cycle life corresponds to that of the average healthy individual during a 12-week period. Considering that patients who have had an ACL reconstruction are less ambulatory than normal immediately following surgery and that biologic incorporation of the graft should be well developed by 12 weeks thus decreasing the load transmitted to the fixation device, the FDT can be safely implanted in humans without undue risk of structural failure. [S0148-0731(00)00606-3]

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.

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