Intraoperative Direct Mechanical Stimulation of the Anterior Cruciate Ligament Elicits Short- and Medium-Latency Hamstring Reflexes

2005 ◽  
Vol 94 (6) ◽  
pp. 3996-4001 ◽  
Author(s):  
B. Friemert ◽  
M. Faist ◽  
C. Spengler ◽  
H. Gerngross ◽  
L. Claes ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Mechanical Stimulation ◽  
Local Anesthetics ◽  
Cruciate Ligament ◽  
Maximum Amplitude ◽  
Afferent Input ◽  
Reflex Response ◽  
Surgical Reconstruction ◽  
Anterior Cruciate ◽  
Stimulation Of

The anterior cruciate ligament (ACL) has not only a mechanical but also a sensorimotor function. Patients with injuries of the ACL frequently complain of knee instability despite good mechanical stabilization after surgical reconstruction. Compared with healthy subjects, their latencies of hamstring reflexes after anterior tibia translation are considerably increased. There is evidence for the existence of a reflex arc between the ACL and the hamstrings. The aim of this study was to determine if there is a direct reflex response after an isolated mechanical stimulation of the ACL in humans. In 10 patients who underwent arthroscopy, hamstring electromyographic (EMG) responses were assessed intraoperatively after applying an isolated load on the ACL. Latencies, amplitudes, and integrals of the EMG responses were analyzed. In four patients, the measurements were repeated after injection of local anesthetics into the ACL. In all subjects, responses with mean latencies of 42 ± 4.4 (SD) ms corresponding to a medium latency response (MLR) were found. In seven subjects, they were preceded by responses with a short-latency (SLR) of 24 ± 2.7 ms. The maximum amplitude was 8.6 ± 7 mV, the integral 0.064 ± 0.05 mV*s. The injection of local anesthetics reduced the amplitude by 34 ± 12% and the integral by 50 ± 20%. Direct mechanical stimulation of the ACL evokes considerably smaller SLRs and MLRs than anterior tibia translation during standing. It is argued that latency changes observed in patients with ACL ruptures may be rather due to changes in the sensorimotor integration of the afferent input from the knee joint than to the absence of the direct ACL reflex.

Bioreactor and scaffold design for the mechanical stimulation of anterior cruciate ligament grafts

2013 ◽  
Vol 23 (3) ◽  
pp. 225-237 ◽  
Author(s):  
M. Hohlrieder ◽  
A.H. Teuschl ◽  
K. Cicha ◽  
M. van Griensven ◽  
H. Redl ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Mechanical Stimulation ◽  
Cruciate Ligament ◽  
Scaffold Design ◽  
Anterior Cruciate ◽  
Stimulation Of

Factors affecting graft force in surgical reconstruction of the anterior cruciate ligament

1990 ◽  
Vol 8 (4) ◽  
pp. 514-521 ◽  
Author(s):  
Jack L. Lewis ◽  
William D. Lew ◽  
Lars Engebretsen ◽  
Robert E. Hunter ◽  
Curtis Kowalczyk
Keyword(s):  
Anterior Cruciate Ligament ◽  
Cruciate Ligament ◽  
Surgical Reconstruction ◽  
Factors Affecting ◽  
Anterior Cruciate

scholarly journals Evaluation of Anterior Cruciate Ligament Surgical Reconstruction Through Finite Element Analysis

2021 ◽  
Author(s):  
Konstantinos Risvas ◽  
Dimitar Stanev ◽  
Lefteris Benos ◽  
Konstantinos Filip ◽  
Dimitrios Tsaopoulos ◽  
...  
Keyword(s):  
Finite Element ◽  
Anterior Cruciate Ligament ◽  
Reference Model ◽  
Numerical Models ◽  
Cruciate Ligament ◽  
Surgical Techniques ◽  
Surgical Reconstruction ◽  
Modeling Framework ◽  
Element Analysis ◽  
Anterior Cruciate

Abstract Anterior Cruciate Ligament (ACL) tear is one of the most common knee injuries. The ACL reconstruction surgery aims to restore healthy knee function by replacing the injured ligament with a graft. Proper selection of the optimal surgery parameters is a complex task. To this end, we developed an automated modeling framework that accepts subject-specific geometries and produces finite element knee models incorporating different surgical techniques. Initially, we developed a reference model of the intact knee, validated with data provided by the OpenKnee project. This helped us evaluate the effectiveness of estimating ligament stiffness directly from MRI. Next, we performed a plethora of “what-if” simulations, comparing responses with the reference model. We found that a) increasing graft pretension and radius reduces relative knee displacement, b) the correlation of graft radius and tension should not be neglected, c) graft fixation angle of 20 degrees can reduce knee laxity, and d) single-versus double-bundle techniques demonstrate comparable performance in restraining knee translation. In most cases, these findings confirm reported values from comparative clinical studies. The numerical models are made publicly available, allowing for experimental reuse and lowering the barriers for meta-studies. The modeling approach proposed here can complement orthopedic surgeons in their decision-making.

scholarly journals Nationwide survey on the use of local antibiotics during anterior cruciate ligament reconstruction in Norway

2020 ◽  
Author(s):  
Monica Alessandria Sailer ◽  
Inge Skråmm ◽  
Einar Andreas Sivertsen ◽  
Stein Håkon Lygre ◽  
Asbjørn Årøen
Keyword(s):  
Anterior Cruciate Ligament ◽  
Anterior Cruciate Ligament Reconstruction ◽  
Ligament Reconstruction ◽  
Cruciate Ligament ◽  
Nationwide Survey ◽  
Surgical Reconstruction ◽  
Local Antibiotics ◽  
Cruciate Ligament Reconstruction ◽  
Anterior Cruciate

Abstract Objective: The use of local antibiotics in surgical reconstruction of the anterior cruciate ligament (ACLR) in Europe and Scandinavia is increasing.We wanted to survey the scope of this practice in Norway. In cooperation with the Norwegian cruciate ligament registry we contacted all institutions in Norway performing ACLR to find out.Results: The results showed that the practice of local antibiotics in ACLR is not widely used in Norway.

scholarly journals Gait Analysis and Knee Kinematics in Patients with Anterior Cruciate Ligament Rupture: Before and After Reconstruction

2020 ◽  
Vol 10 (10) ◽  
pp. 3378
Author(s):  
Dmitry Skvortsov ◽  
Sergey Kaurkin ◽  
Alexander Akhpashev ◽  
Aljona Altukhova ◽  
Alexander Troitskiy ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Gait Analysis ◽  
Acl Reconstruction ◽  
Cruciate Ligament ◽  
Surgical Reconstruction ◽  
Control Group ◽  
Cycle Duration ◽  
Post Surgery ◽  
Before And After ◽  
Anterior Cruciate

The objective of the study was to evaluate the clinical, functional, and biomechanical symptoms in patients with anterior cruciate ligament (ACL) rupture before and after ACL reconstruction. The study enrolled 20 patients and 20 healthy subjects as controls. Walking biomechanics was assessed at three time points: before surgery and three months and a year or more after surgical reconstruction. Impact loads on both sides differed significantly from the respective values before surgery (p<0.05). Walking cycle duration decreased with time after surgery. On both sides (affected and unaffected), hip movement amplitudes were significantly smaller than in control (p<0.05). They remained so in the follow-up periods after the reconstruction. Before ACL reconstruction, the amplitude of the main flexion of the knee was significantly reduced both on the affected and unaffected sides. The amplitude gradually increased after the reconstruction, and a year post-surgery, it reached, on the operated side, the same values as in the control group. Complete functional recovery of the knee joint was not achieved within a year after the ACL surgical reconstruction. The remaining changes, however, were not clinically pronounced and could only be detected by instrumental gait analysis. The compensatory processes developed bilaterally, in both the hip and knee joints.

Use Caution When Assessing Preoperative Leg-Length Discrepancy in Pediatric Patients With Anterior Cruciate Ligament Injuries

2020 ◽  
Vol 48 (12) ◽  
pp. 2948-2953
Author(s):  
Madison R. Heath ◽  
Alexandra H. Aitchison ◽  
Lindsay M. Schlichte ◽  
Christine Goodbody ◽  
Frank A. Cordasco ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Acl Reconstruction ◽  
Cruciate Ligament ◽  
Intraclass Correlation ◽  
Case Series ◽  
Surgical Reconstruction ◽  
Radiographic Examination ◽  
Leg Length ◽  
Level Of Evidence ◽  
Anterior Cruciate

Background: Pre- and postoperative standing hip-to-ankle radiographs are critical for monitoring potential postoperative growth arrest and resultant deformities after pediatric anterior cruciate ligament (ACL) reconstruction. Purpose: To determine the prevalence of apparent preoperative leg-length discrepancies (LLDs) that resolve at the first postoperative radiographic examination in patients undergoing ACL reconstruction in order to understand what proportion of the noted preoperative deformities may have been inaccurate. Study Design: Case series; Level of evidence, 4. Methods: A retrospective review of prospectively collected preoperative and first postoperative full-length hip-to-ankle radiographs was performed in a cohort of skeletally immature patients who had an acute ACL injury and underwent subsequent surgical reconstruction. Leg length measurements for both the injured and the uninjured legs were obtained for comparison. Results: A total of 112 patients (mean age, 12.7 ± 1.7 years) were included (79 boys and 33 girls). Leg-length measurement interrater reliability among 3 raters for 25 randomly chosen images was nearly perfect (intraclass correlation coefficient, 0.996; 95% CI, 0.994-0.998). At baseline, there was no apparent preoperative LLD (<5 mm) in 48% (n = 54) of participants, while 37% (n = 41) displayed a small apparent LLD (5 to <10 mm), 12% (n = 13) displayed a moderate apparent LLD (10 to <15 mm), and 4% (n = 4) displayed a large apparent LLD (≥15 mm). Of the patients with an apparent preoperative LLD, 66% (n = 38) of them tore their ACL on the leg measuring shorter. At first postoperative radiographs, 48% (n = 28) of patients with an apparent preoperative LLD showed resolution to no LLD: 46% (n = 19) of patients with a small apparent preoperative LLD, 54% (n = 7) of patients with a moderate apparent LLD, and 50% (n = 2) of patients with a large apparent LLD. Conclusion: A high percentage of patients (48%) with apparent preoperative LLDs showed resolution to no LLDs by their first postoperative imaging, indicating that preoperative hip-to-ankle radiographs display some false LLDs in patients with recent ACL tears who are unable to fully extend their injured leg and bear weight.

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