Effects of the Ankle Flexion Angle During Anterior Talofibular Ligament Reconstruction on Ankle Kinematics, Laxity, and In Situ Forces of the Reconstructed Graft

2022 ◽  
pp. 107110072110693
Author(s):  
Yuzuru Sakakibara ◽  
Atsushi Teramoto ◽  
Tetsuya Takagi ◽  
Satoshi Yamakawa ◽  
Hiroaki Shoji ◽  
...  

Background: This study aimed to evaluate the effects of the ankle flexion angle during anterior talofibular ligament (ATFL) reconstruction on ankle kinematics, laxity, and in situ force of a graft. Methods: Twelve cadaveric ankles were evaluated using a 6–degrees of freedom robotic system to apply passive plantar flexion and dorsiflexion motions and multidirectional loads. A repeated measures experiment was designed using the intact ATFL, transected ATFL, and reconstructed ATFL. During ATFL reconstruction (ATFLR), the graft was fixed at a neutral position (ATFLR 0 degrees), 15 degrees of plantar flexion (ATFLR PF15 degrees), and 30 degrees of plantar flexion (ATFLR PF30 degrees) with a constant initial tension of 10 N. The 3-dimensional path and reconstructed graft tension were simultaneously recorded, and the in situ force of the ATFL and reconstructed grafts were calculated using the principle of superposition. Results: The in situ forces of the reconstructed grafts in ATFLR 0 degrees and ATFLR PF 15 degrees were significantly higher than those of intact ankles. The ankle kinematics and laxity produced by ATFLR PF 30 degrees were not significantly different from those of intact ankles. The in situ force on the ATFL was 19.0 N at 30 degrees of plantar flexion. In situ forces of 41.0, 33.7, and 21.9 N were observed at 30 degrees of plantar flexion in ATFLR 0, 15, and 30 degrees, respectively. Conclusion: ATFL reconstruction with the peroneus longus (PL) tendon was performed with the graft at 30 degrees of plantar flexion resulted in ankle kinematics, laxity, and in situ forces similar to those of intact ankles. ATFL reconstructions performed with the graft fixed at 0 and 15 degrees of the plantar flexion resulted in higher in situ forces on the reconstructed graft. Clinical Relevance: Fixing the ATFL tendon graft at 30 degrees of plantar flexion results in an in situ force closest to that of an intact ankle and avoids the excessive tension on the reconstructed graft.

2020 ◽  
Vol 48 (4) ◽  
pp. 916-922
Author(s):  
Yuzuru Sakakibara ◽  
Atsushi Teramoto ◽  
Tetsuya Takagi ◽  
Satoshi Yamakawa ◽  
Hiroaki Shoji ◽  
...  

Background: Although a variety of surgical procedures for anterior talofibular ligament (ATFL) reconstruction have been reported, the effect of initial graft tension during ATFL reconstruction remains unclear. Purpose/Hypothesis: This study investigated the effects of initial graft tension on ATFL reconstruction. We hypothesized that a high degree of initial graft tension would cause abnormal kinematics and laxity. Study Design: Controlled laboratory study. Methods: Twelve cadaveric ankles were tested with a robotic system with 6 degrees of freedom to apply passive plantarflexion and dorsiflexion motions and a multidirectional load. A repeated measures experiment was designed with the intact ATFL, transected ATFL, and reconstructed ATFL at initial tension conditions of 10, 30, 50, and 70 N. The 3-dimensional path and reconstructed graft tension were simultaneously recorded, and the in situ forces of the ATFL and reconstructed graft were calculated with the principle of superposition. Results: Initial tension of 10 N was sufficient to imitate normal ankle kinematics and laxity, which were not significantly different when compared with those of the intact ankles. The in situ force on the reconstructed graft tended to increase as the initial tension increased. In situ force on the reconstructed graft >30 N was significantly greater than that of intact ankles. The in situ force on the ATFL was 19 N at 30° of plantarflexion. In situ forces of 21.9, 30.4, 38.2, and 46.8 N were observed at initial tensions of 10, 30, 50, and 70 N, respectively, at 30° of plantarflexion. Conclusion: Approximate ankle kinematic patterns and sufficient laxity, even with an initial tension of 10 N, could be obtained immediately after ATFL reconstruction. Moreover, excessive initial graft tension during ATFL reconstruction caused excessive in situ force on the reconstructed graft. Clinical Relevance: This study revealed the effects of initial graft tension during ATFL reconstruction. These data suggest that excessive tension during ATFL reconstruction should be avoided to ensure restoration of normal ankle motion.


2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0041
Author(s):  
Yuzuru Sakakibara ◽  
Atsushi Teramoto ◽  
Tomoaki Kamiya ◽  
Kota Watanabe ◽  
Toshihiko Yamashita

Category: Basic Sciences/Biologics Introduction/Purpose: Ankle sprains are the most common sports injuries, and anterior talofibular ligament (ATFL) injury comprised 85% of all ankle sprains. Most patients recover with conservative treatment, but 20% of them progress to chronic ankle instability. Some studies have reported that anatomic reconstruction using a tendon graft is one of the best procedures to restore the ankle to its condition before symptom development. However, the effect of initial graft tension during ATFL reconstruction is still unclear. Therefore, the objective of this study was to investigate the effect of the initial graft tension during ATFL reconstruction. Methods: Eight fresh-frozen cadaveric ankle specimens were subjected to passive plantarflexion (PF)-dorsiflexion (DF) movement from 15° DF to 30° PF using the 6-degree-freedom robotic system. In addition, 60 N of anterior-posterior load, 1.7 Nm of inversion-eversion (IV-EV) torque, and 1.7 Nm of internal-external rotation (IR-ER) torque were applied to the ankle. During testing, 3-dimensional paths of the ankle were recorded simultaneously. Furthermore, in-situ forces of the ATFL and reconstructed graft were calculated using the principle of superposition. A repeated experiment was designed with the intact condition (intact), ATFL transection, and ATFL reconstruction with four different initial graft tensions (10 N, 30 N, 50 N, and 70 N). Results: AP laxity, IV-EV laxity and IR-ER laxity with ATFL transection was significantly greater than those with intact. In ATFL transection, the talus was significantly translated anteriorly with inversion and internal rotations under passive PF-DF motion compared with intact. Kinematic patterns and laxity in ATFL reconstruction with initial tension of 10 N and 30 N almost imitated intact, but in ATFL reconstruction with initial tension 70 N, the talus was significantly translated with external rotation compared with intact. As the initial graft tension during ATFL reconstruction increased, in-situ force of the reconstructed graft tended to increase during PF-DF motion. In-situ force of the reconstructed graft tension was significantly greater with initial tensions of 50 N, and 70 N than with intact during PF-DF motion (Figure 1). Conclusion: ATFL deficiency altered ankle kinematics and laxity. Although the optimal initial graft tension during ATFL reconstruction might restore ankle kinematics and laxity, excessive initial graft tension caused abnormal kinematics and laxity. Furthermore, the reconstructed graft tension increased as the initial tension increased. Initial tension during ATFL reconstruction has the important effect of imitating the normal ankle condition. We suggest that over-tensioning during ATFL reconstruction should be avoided in order to imitate the conditions of a normal ankle.


2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0006
Author(s):  
Yuzuru Sakakibara ◽  
Atsushi Teramoto ◽  
Hiroaki Shoji ◽  
Tonmoaki Kamiya ◽  
Kota Watanabe ◽  
...  

Category: Ankle, Basic Sciences/Biologics Introduction/Purpose: Anatomical anterior talofibular ligament (ATFL) reconstruction is a standard surgical treatment for chronic lateral ankle instability. The optimal position during ATFL reconstruction is still uncertain. The purpose of this study was to investigate the effect of ankle position during ATFL reconstruction on ankle kinematics, laxity, and in-situ force on the graft. Methods: Twelve fresh-frozen cadaveric ankles were evaluated. First, ankle specimens were subjected to passive plantarflexion (PF)-dorsiflexion (DF) movement, from 15° DF to 30° PF, using a 6-degrees-of-freedom robotic system. Then, 60 N of anterior- posterior (AP) load, 1.7 Nm of inversion-eversion (IV-EV) torque, and 1.7 Nm of internal-external rotation (IR-ER) torque were applied to the ankle. During testing, 3-dimensional paths of the ankle were recorded simultaneously. In-situ forces on the ATFL and reconstructed graft were calculated using the principle of superposition. A repeat experiment was designed with intact (intact), ATFL transection, and ATFL reconstruction conditions, using 3 different flexion angles (Group A: 0°, Group B: PF 15°, Group C: PF 30°). Results: In ATFL transection condition, the talus was significantly translated anteriorly with internal rotation during PF-DF motion, compared to that in intact condition. In addition, laxity in AP, IV-EV, and IR-ER conditions was significantly greater than in intact condition. In each ATFL reconstruction group, kinematics and laxity showed no significant difference compared to that in intact condition. In intact condition, in-situ force was maximal at PF 30° (19.0±12.0 N). The in-situ force on the reconstructed graft in Group A, B, and C at PF 30° was 50.0±12.4 N, 33.7±13.0 N, and 21.9±7.5 N. The in-situ force in Group A and B was significantly greater than in intact condition. The in-situ force in Group C was not significantly different compared to that in intact condition (Figure 1). Conclusion: Ankle position during ATFL reconstruction affected in-situ force on the reconstructed graft. ATFL reconstruction at PF 30° is recommended to avoid excessive in-situ force on the reconstructed graft.


2008 ◽  
Vol 43 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Thomas Kernozek ◽  
Christopher J. Durall ◽  
Allison Friske ◽  
Matthew Mussallem

Abstract Context: Ankle braces may enhance ankle joint proprioception, which in turn may affect reflexive ankle muscle activity during a perturbation. Despite the common occurrence of plantar-flexion inversion ankle injuries, authors of previous studies of ankle muscle latencies have focused on inversion stresses only. Objective: To examine the latency of the peroneus longus (PL), peroneus brevis (PB), and tibialis anterior (TA) muscles in response to various degrees of combined plantar-flexion and inversion stresses in braced and unbraced asymptomatic ankles. Design: Repeated measures. Setting: University biomechanics laboratory. Patients or Other Participants: Twenty-eight healthy females and 12 healthy males (n = 40: mean age = 23.63 years, range = 19 to 30 years; height = 172.75 ± 7.96 cm; mass = 65.53 ± 12.0 kg). Intervention(s): Participants were tested under 2 conditions: wearing and not wearing an Active Ankle T1 brace while dropping from a custom-made platform into 10°, 20°, and 30° of plantar flexion and 30° of inversion. Main Outcome Measure(s): The time between platform drop and the onset of PL, PB, and TA electromyographic activity was measured to determine latencies. We calculated a series of 2-way analyses of variance to determine if latencies were different between the conditions (braced and unbraced) and among the plantar-flexion angles (α = .05). Results: No interaction was found between condition and plantar-flexion angle. No significant main effects were found for condition or plantar-flexion angle. Overall means for braced and unbraced conditions were not significantly different for each muscle tested. Overall means for angle for the PL, PB, and TA were not significantly different. Conclusions: Reflexive activity of the PL, PB, or TA was unaffected by the amount of plantar flexion or by wearing an Active Ankle T1 brace during an unanticipated plantar-flexion inversion perturbation.


2017 ◽  
Vol 52 (5) ◽  
pp. 411-421
Author(s):  
David M. Bazett-Jones ◽  
Wendy Huddleston ◽  
Stephen Cobb ◽  
Kristian O'Connor ◽  
Jennifer E. Earl-Boehm

Context:  Patellofemoral pain (PFP) is typically exacerbated by repetitive activities that load the patellofemoral joint, such as running. Understanding the mediating effects of changes in pain in individuals with PFP might inform injury progression, rehabilitation, or both. Objective:  To investigate the effects of changing pain on muscular strength and running biomechanics in those with PFP. Design:  Crossover study. Setting:  University research laboratory. Patients or Other Participants:  Seventeen participants (10 men, 7 women) with PFP. Intervention(s):  Each participant completed knee pain-reducing and pain-inducing protocols in random order. The pain-reducing protocol consisted of 15 minutes of transcutaneous electric nerve stimulation (TENS) around the patella. The pain-inducing protocol was sets of 20 repeated single-legged squats (RSLS). Participants completed RSLS sets until either their pain was within at least 1 cm of their pain during an exhaustive run or they reached 10 sets. Main Outcome Measure(s):  Pain, isometric hip and trunk strength, and running mechanics were assessed before and after the protocols. Dependent variables were pain, normalized strength (abduction, extension, external rotation, lateral trunk flexion), and peak lower extremity kinematics and kinetics in all planes. Pain scores were analyzed using a Friedman test. Strength and mechanical variables were analyzed using repeated-measures analyses of variance. The α level was set at P < .05. Results:  Pain was decreased after the TENS (pretest: 3.10 ± 1.95, posttest: 1.89 ± 2.33) and increased after the RSLS (baseline: 3.10 ± 1.95, posttest: 4.38 ± 2.40) protocols (each P < .05). The RSLS protocol resulted in a decrease in hip-extension strength (baseline: 0.355 ± 0.08 kg/kg, posttest: 0.309 ± 0.09 kg/kg; P < .001). Peak plantar-flexion angle was decreased after RSLS (baseline: −13.97° ± 6.41°, posttest: −12.84° ± 6.45°; P = .003). Peak hip-extension (pretest: −2.31 ± 0.46) and hip-abduction (pretest: −2.02 ± 0.35) moments decreased after both the TENS (extension: −2.15 ± 0.48 Nm/kg, P = .015; abduction: −1.91 ± 0.33 Nm/kg, P = .015) and RSLS (extension: −2.18 ± 0.52 Nm/kg, P = .003; abduction: −1.87 ± 0.36 Nm/kg, P = .039) protocols. Conclusions:  This study presents a novel and effective method of increasing pain in persons with PFP. Functionally increased pain after RSLS coincides with reduced hip-extensor muscle strength and decreased plantar-flexion angle during running. The TENS treatment decreased pain during running in those with PFP but failed to influence strength. Hip moments were reduced by both protocols, which may demonstrate that acute increases or decreases in pain cause runners to change their mechanics.


2013 ◽  
Vol 48 (3) ◽  
pp. 337-345 ◽  
Author(s):  
Matthew K. Seeley ◽  
Jihong Park ◽  
Daniel King ◽  
J. Ty Hopkins

Context: Knee injuries are prevalent, and the associated knee pain is linked to disability. The influence of knee pain on movement biomechanics, independent of other factors related to knee injuries, is difficult to study and unclear. Objective: (1) To evaluate a novel experimental knee-pain model and (2) better understand the independent effects of knee pain on walking and running biomechanics. Design: Crossover study. Setting: Biomechanics laboratory. Patients or Other Participants: Twelve able-bodied volunteers (age = 23 ± 3 years, height = 1.73 ± 0.09 m, mass = 75 ± 14 kg). Intervention(s): Participants walked and ran at 3 time intervals (preinfusion, infusion, and postinfusion) for 3 experimental conditions (control, sham, and pain). During the infusion time interval for the pain and sham conditions, hypertonic or isotonic saline, respectively, was continuously infused into the right infrapatellar fat pad for 22 minutes. Main Outcome Measure(s): We used repeated-measures analyses of variance to evaluate the effects of time and condition on (1) perceived knee pain and (2) key biomechanical characteristics (ground reaction forces, and joint kinematics and kinetics) of walking and running (P < .05). Results: The hypertonic saline infusion (1) increased perceived knee pain throughout the infusion and (2) reduced discrete characteristics of each component of the walking ground reaction force, walking peak plantar-flexion angle (range = 62°–67°), walking peak plantar-flexion moment (range = 95–104 N·m), walking peak knee-extension moment (range = 36–49 N·m), walking peak hip-abduction moment (range = 62–73 N·m), walking peak support moment (range = 178–207 N·m), running peak plantar-flexion angle (range = 38°–77°), and running peak hip-adduction angle (range = 5–21°). Conclusions: This novel experimental knee pain model consistently increased perceived pain during various human movements and produced altered running and walking biomechanics that may cause abnormal knee joint-loading patterns.


2002 ◽  
Vol 23 (9) ◽  
pp. 825-832 ◽  
Author(s):  
Satoru Ozeki ◽  
Kazunori Yasuda ◽  
Kiyoshi Kaneda ◽  
Kenichi Yamakoshi ◽  
Takahiro Yamanoi

The strain changes of the central part of the anterior talofibular ligament (ATFL), the posterior talofibular ligament (PTFL), the calcaneofibular ligament (CFL), and the tibiocalcaneal ligament (TCL) were measured simultaneously for a full range of ankle motion. Twelve fresh frozen amputated ankles were used. To measure the strain changes of the ligaments, a Galium-lndium-filled silastic strain transducer was implanted in the center of each ligament. The zero strain reference was determined immediately after the measurement of strain changes in five of the 12 ankles by tensile testing of each bone-ligament-bone preparation. The maximum strain change of the ATFL, the PTFL, the CFL and the TFL were 7.9%, 5.9%, 5.3% and 5.2%, respectively. The ATFL was elongated in plantar flexion and shortened in dorsiflexion. The PTFL and the CFL were shortened in plantar flexion and elongated in dorsiflexion. The TCL was the longest around the neutral position and became shorter in planter flexion and dorsiflexion. The results showed that the ATFL was taut in plantar flexion over 16.2°, the PTFL and the CFL were taut in dorsiflexion over 18° and 17.8° respectively, and the TCL was taut between 9.5° of dorsiflexion and 9.5° of plantar flexion. The length change pattern was different among the ankle ligaments, although there was only a slight difference between that of the PTFL and the CFL. This study provides fundamental data useful in studying ankle ligament reconstruction.


2018 ◽  
Vol 23 (suppl_1) ◽  
pp. e16-e16
Author(s):  
Ahmed Moussa ◽  
Audrey Larone-Juneau ◽  
Laura Fazilleau ◽  
Marie-Eve Rochon ◽  
Justine Giroux ◽  
...  

Abstract BACKGROUND Transitions to new healthcare environments can negatively impact patient care and threaten patient safety. Immersive in situ simulation conducted in newly constructed single family room (SFR) Neonatal Intensive Care Units (NICUs) prior to occupancy, has been shown to be effective in testing new environments and identifying latent safety threats (LSTs). These simulations overlay human factors to identify LSTs as new and existing process and systems are implemented in the new environment OBJECTIVES We aimed to demonstrate that large-scale, immersive, in situ simulation prior to the transition to a new SFR NICU improves: 1) systems readiness, 2) staff preparedness, 3) patient safety, 4) staff comfort with simulation, and 5) staff attitude towards culture change. DESIGN/METHODS Multidisciplinary teams of neonatal healthcare providers (HCP) and parents of former NICU patients participated in large-scale, immersive in-situ simulations conducted in the new NICU prior to occupancy. One eighth of the NICU was outfitted with equipment and mannequins and staff performed in their native roles. Multidisciplinary debriefings, which included parents, were conducted immediately after simulations to identify LSTs. Through an iterative process issues were resolved and additional simulations conducted. Debriefings were documented and debriefing transcripts transcribed and LSTs classified using qualitative methods. To assess systems readiness and staff preparedness for transition into the new NICU, HCPs completed surveys prior to transition, post-simulation and post-transition. Systems readiness and staff preparedness were rated on a 5-point Likert scale. Average survey responses were analyzed using dependent samples t-tests and repeated measures ANOVAs. RESULTS One hundred eight HCPs and 24 parents participated in six half-day simulation sessions. A total of 75 LSTs were identified and were categorized into eight themes: 1) work organization, 2) orientation and parent wayfinding, 3) communication devices/systems, 4) nursing and resuscitation equipment, 5) ergonomics, 6) parent comfort; 7) work processes, and 8) interdepartmental interactions. Prior to the transition to the new NICU, 76% of the LSTs were resolved. Survey response rate was 31%, 16%, 7% for baseline, post-simulation and post-move surveys, respectively. System readiness at baseline was 1.3/5,. Post-simulation systems readiness was 3.5/5 (p = 0.0001) and post-transition was 3.9/5 (p = 0.02). Staff preparedness at baseline was 1.4/5. Staff preparedness post-simulation was 3.3/5 (p = 0.006) and post-transition was 3.9/5 (p = 0.03). CONCLUSION Large-scale, immersive in situ simulation is a feasible and effective methodology for identifying LSTs, improving systems readiness and staff preparedness in a new SFR NICU prior to occupancy. However, to optimize patient safety, identified LSTs must be mitigated prior to occupancy. Coordinating large-scale simulations is worth the time and cost investment necessary to optimize systems and ensure patient safety prior to transition to a new SFR NICU.


Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 48
Author(s):  
Junya Saeki ◽  
Soichiro Iwanuma ◽  
Suguru Torii

The structure of the first toe is independent of that of the other toes, while the functional difference remains unclear. The purpose of this study was to investigate the difference in the force generation characteristics between the plantar-flexion of the first and second–fifth metatarsophalangeal joints (MTPJs) by comparing the maximal voluntary plantar-flexion torques (MVC torque) at different MTPJs and ankle positions. The MVC torques of the first and second–fifth MTPJs were measured at 0°, 15°, 30°, and 45° dorsiflexed positions of the MTPJs, and at 20° plantar-flexed, neutral, and 20° dorsiflexed positions of the ankle. Two-way repeated measures analyses of variance with Holm’s multiple comparison test (MTPJ position × ankle position) were performed. When the MTPJ was dorsiflexed at 0°, 15°, and 30°, the MVC torque of the first MTPJ when the ankle was dorsiflexed at 20° was higher than that when the ankle was plantar-flexed at 20°. However, the ankle position had no significant effect on the MVC torque of the second–fifth MTPJ. Thus, the MVC torque of the first MTPJ was more affected by the ankle position than the second–fifth MTPJs.


2014 ◽  
Vol 44 (10) ◽  
pp. 1845-1852 ◽  
Author(s):  
Michelle Schalemberg Diehl ◽  
Clair Jorge Olivo ◽  
Carlos Alberto Agnolin ◽  
Ricardo Lima de Azevedo Junior ◽  
Vinícius Felipe Bratz ◽  
...  

The objective of this research was to evaluate of three grazing systems (GS) with elephant grass (EG), Italian ryegrass (IR) + spontaneous growing species (SGS); EG + IR + SGS + forage peanut (FP); and EG + IR + SGS + red clover (RC), during the winter and summer periods in rotational grazing with dairy cattle. Experimental design was completely randomized with three treatments, two replicates with repeated measures. Lactating Holstein cows receiving 1% BW-daily feed supplement with concentrate were used in the evaluation. Eight grazing cycles were performed during the experimental period. The values of pre forage mass and stocking rate were 2.52, 2.60 and 2.99 t ha-1 and 2.64, 2.77 and 3.14 animal unit ha-1, respectively for GS. Samples of forage were collected by hand-plucking technique to analyze the crude protein (CP), neutral detergent fiber (NDF), in situ dry matter digestibility (ISDMD), in situ organic matter digestibility (ISOMD) of forage present between rows of elephant grass, in the rows of elephant grass and the legumes. Higher value of CP, ISOMD and lower of NDF were observed for the grazing systems mixed with legumes forage.


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