scholarly journals Effect of Achilles tendon lengthening on ankle and subtalar joint orientation and load distribution utilizing a novel cadaveric model to simulate weight bearing

2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0021
Author(s):  
Naven Duggal ◽  
Patrick Williamson ◽  
Stephen Okajima ◽  
Peter Biggane ◽  
Michael Nasr ◽  
...  
Keyword(s):  
Achilles Tendon ◽  
Contact Area ◽  
Subtalar Joint ◽  
Peak Pressure ◽  
Weight Bearing ◽  
Joint Orientation ◽  
Ankle Arthroplasty ◽  
Tendon Lengthening ◽  
Mean Pressure ◽  
Achilles Tendon Lengthening

Category: Basic Sciences/Biologics Introduction/Purpose: Ankle arthroplasties are increasingly performed to address ankle arthritis. Patients with long standing ankle arthritis often present with an associated achilles tendon contracture. An open or percutaneous lengthening of the Achilles is commonly performed at the same time as the ankle arthroplasty to improve range of motion. Current ankle arthroplasty implants include mobile bearing and fixed bearing systems. Lengthening the achilles tendon improves dorsiflexion, however the effect of the lengthening on the ankle and subtalar joint is not well documented in the literature. Using a novel system to simulate weight bearing in a cadaveric model, we evaluated achilles tendon lengthening and its effect on ankle and subtalar joint orientation and load distribution. This may have potential implications to polyethylene implant longevity in total ankle arthroplasties. Methods: Five fresh frozen lower limb cadaveric specimens without known skeletal condition were used. The femoral head was potted with PMMA and TekScan pressure sensors were inserted into the ankle and subtalar joint. The specimens were placed on a custom jig, which allowed for load cell modulated loading of the leg; 75 lb load (half body weight)(4) was applied at the femoral head while the foot was supported against a fixed plate keeping the ankle in neutral position. Mean pressure (MP), peak pressure (PP), contact area (CA), and center of force (COF) were measured in both joints under two conditions; baseline (BASE), and following Achilles tendon release (TENDON) to simulate lengthening. Each condition was tested three times per specimen; the results were averaged per specimen and used for final analysis. Displacement of COF was calculated relative to its location at baseline. Results: The Mean Pressure (MP), Peak Pressure (PP) and Contact Area (CA) did not show a statistical difference in the ankle and subtalar joints between baseline (BASE) and TENDON (Achilles tendon release) conditions. (Table 1). Further, the displacement of the COF from the BASE to TENDON was 0.5 mm. In our model, the contracture of the muscle was not fully simulated. Further hindfoot kinetic studies with active achilles contracture may demonstrate a difference in contact forces in the ankle and subtalar joint as compared to normal. Conclusion: Ankle arthroplasty is becoming an effective treatment option for ankle joint arthritis. Our novel study demonstrates that Achilles tendon lengthening did not change the mean pressure, peak pressure, contact area center of force in the ankle and subtalar joint. This model provides validation for further studies evaluating tendon release and contact pressure changes in a cadaver with an implanted fixed bearing versus mobile bearing total ankle prosthesis. Difference in polyethylene wear may effect the longevity of ankle replacements. This study will provide clinicians additional information when evaluating the benefit/risks associated with lengthening the Achilles tendon for ankle arthroplasty patients.

scholarly journals The Effect of Orthotics on Ankle and Subtalar Joint Orientation and Load Distribution Utilizing a Novel System to Simulate Weight Bearing in a Cadaveric Model

2017 ◽  
Vol 2 (3) ◽  
pp. 2473011417S0001
Author(s):  
Naven Duggal ◽  
Ara Nazarian ◽  
Michael Nasr ◽  
Patrick Williamson ◽  
Stephen Okajima ◽  
...  
Keyword(s):  
Body Weight ◽  
Femoral Head ◽  
Lower Limb ◽  
Load Distribution ◽  
Subtalar Joint ◽  
Peak Pressure ◽  
Weight Bearing ◽  
Joint Orientation ◽  
Mean Pressure ◽  
Cadaveric Model

Category: Ankle, Basic Sciences/Biologics, Hindfoot, Biomechanics Introduction/Purpose: Orthotics are commonly prescribed by orthopaedic surgeons to address the hindfoot and midfoot deformity resulting from posterior tibial tendon dysfunction. The public however will often purchase over the counter orthotics for generalized complaints of foot pain that is not associated with any significant deformity or foot pathology. The mechanical axis of the lower limb may be altered in patients who use orthotics despite a normal foot alignment. We hypothesize that patients with normal alignment who use orthotics may adversely change ankle and subtalar joint orientation and load distribution. Methods: Five fresh frozen lower limb cadaveric specimens without known skeletal condition were used. The femoral head was potted with PMMA and TekScan pressure sensors were inserted into the ankle and subtalar joint. The specimens were placed on a custom jig, which allowed for load cell modulated loading of the leg; 75 lb load (half body weight) was applied at the femoral head while the foot was supported against a fixed plate keeping the ankle in neutral position. Testing was achieved by placing an orthotic under the medial half of the plantar talonavicular joint level. Mean pressure (MP), peak pressure (PP), contact area (CA), and center of force (COF) were measured in both the ankle and subtalar joints under three conditions; barefoot (BASE), with a 1.5 cm (ORT1) and 3 cm (ORT2) height orthotic. Each condition was tested three times per specimen. Displacement of COF was calculated relative to its location at baseline. Results: The MP, PP and CA showed a constant decrease from BASE to ORT1 and ORT2. Despite this relation, the only comparison that was significantly different was that between peak pressure values of the baseline and ORT2 conditions of the subtalar joint. The average displacement of COF from BASE was 0.14 mm and 0.42 mm medially, and 0.26 mm and 0.46 mm posteriorly at the ankle joint with ORT1 and ORT2 respectively. The average displacement of COF from BASE was 0.03 mm laterally and 0.08 mm posteriorly with ORT1, and 0.2 mm medially and 0.46 mm posteriorly with ORT2 at the subtalar joint. Conclusion: Foot deformities have an impact on the articular forces in the lower limb. Our results agree with previous studies about the role of foot deformity on the distribution of body weight forces and its consequences across the ankle and subtalar joint. Our novel study also demonstrates that orthotics and orthotics of varying sizes can change the mean pressure, peak pressure, contact area center of force in the ankle and subtalar joint. This study proves the feasibility of its design for studying intra-articular pressure changes in a lower limb cadaveric model with simulated weight bearing.

Pressure Distribution in the Ankle and Subtalar Joint With Routine and Oversized Foot Orthoses

2018 ◽  
Vol 39 (8) ◽  
pp. 994-1000 ◽  
Author(s):  
Patrick Williamson ◽  
Aron Lechtig ◽  
Philip Hanna ◽  
Stephen Okajima ◽  
Peter Biggane ◽  
...  
Keyword(s):  
Contact Area ◽  
Lower Limb ◽  
Subtalar Joint ◽  
Peak Pressure ◽  
Weight Bearing ◽  
Force Distribution ◽  
Foot Orthoses ◽  
Pressure Mapping ◽  
Mean Pressure ◽  
Pressure Peak

Background: Foot orthoses are used to treat many disorders that affect the lower limb. These assistive devices have the potential to alter the forces, load distribution, and orientation within various joints in the foot and ankle. This study attempts to quantify the effects of orthoses on the intra-articular force distribution of the ankle and subtalar joint using a cadaveric testing jig to simulate weight bearing. Methods: Five lower-limb cadaveric specimens were placed on a custom jig, where a 334-N (75-lb) load was applied at the femoral head, and the foot was supported against a plate to simulate double-leg stance. Pressure-mapping sensors were inserted into the ankle and subtalar joint. Mean pressure, peak pressure, contact area, and center of force were measured in both the ankle and subtalar joints for barefoot and 2 medial foot orthosis conditions. The 2 orthosis conditions were performed using (1) a 1.5-cm-height wedge to simulate normal orthoses and (2) a 3-cm-height wedge to simulate oversized orthoses. Results: The contact area experienced in the subtalar joint significantly decreased during 3-cm orthotic posting of the medial arch, but neither orthosis had a significant effect on the spatial mean pressure or peak pressure experienced in either joint. Conclusion: The use of an oversized orthosis could lead to a decrease in the contact area and alterations in the distribution of pressure within the subtalar joint. Clinical Relevance: The use of inappropriate orthoses could negatively impact the force distribution in the lower limb.

scholarly journals Ankle and Subtalar Joint Kinematics following Lateral Ligament Repair- Implications for Early Surgical Treatment

2017 ◽  
Vol 2 (3) ◽  
pp. 2473011417S0002
Author(s):  
Kenneth Hunt ◽  
Nicholas Anderson ◽  
Judas Kelley ◽  
Richard Fuld ◽  
Todd Baldini
Keyword(s):  
Motion Capture ◽  
Contact Area ◽  
Subtalar Joint ◽  
Peak Pressure ◽  
Weight Bearing ◽  
Joint Kinematics ◽  
Ligament Repair ◽  
Tibiotalar Joint ◽  
Ligament Healing ◽  
The Impact

Category: Ankle Introduction/Purpose: The current trend for chronic lateral ankle instability treatment is direct repair of the ATFL and/or CFL by open or arthroscopic-assisted technique. There is recent evidence suggesting improved success with acute ligament repair following high grade ankle sprains as well as on the impact of CFL injury on ankle and subtalar biomechanics. However, the impact of acute repair on ankle and subtalar joint kinematics and biomechanics is not well understood. The purpose of this study was to determine the impact of repairing the ATFL alone compared to repairing both the ATFL and CFL, on restoration of ankle and subtalar joint kinematics. Methods: Ten matched pairs of fresh frozen human cadaveric ankles were dissected to expose intact ATFL and CFL. Ankles were mounted to an Instron at 20° plantar flexion and 15° of internal rotation. Each ankle was loaded to body weight and then inverted from 0 to 20° for three cycles; Peak pressure and contact area were recorded in the ankle joint using a calibrated Tekscan sensor system, and linear and rotational displacement of the talus and calcaneus relative to the ankle mortise was recorded using a three-dimensional motion capture system. Ankles then underwent sequential sectioning of ATFL and CFL and were randomly assigned to ATFL-only repair using two arthroscopic Broström all-soft anchors, or combined ATFL and CFL repair. Testing was repeated after repair. Results: Motion capture showed a significant increase in inversion angle of both the calcaneus and talus after release of each ligament. There was significantly more inversion in the subtalar joint than the tibiotalar joint with weight-bearing inversion. There was a significant increased medial shift of the calcaneus after CFL release. Neither ATFL alone nor combined ATFL/CFL repairs restored normal ankle joint inversion. Isolated ATFL repair restored inversion of subtalar joint nearing the intact state. We found no significant difference in peak pressure or contact area in the tibiotalar joint between the intact ankle and ATFL or combined repair. However, there was a 26% decrease in peak pressure following ATFL repair, and only an 11% decrease in peak pressure following ATFL/CFL repair compared to the uninjured ankle. Conclusion: The addition of CFL repair does not appear to provide significant improvement compared to ATFL repair alone in the immediate repair setting. Neither group demonstrated restoration of normal talus inversion with weight-bearing inversion testing, suggesting that acute repair, without a period of ligament healing, is not sufficient to resist a weight-bearing inversion moment. While the CFL plays an important role in normal ankle mechanics, this data supports the necessity for a protection period to allow sufficient ligament-healing before weight-bearing inversion stresses are applied following surgical repair.

scholarly journals Modified Percutaneous Achilles Tendon Lengthening by Triple Hemisection for Achilles Tendon Contracture

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Yangjing Lin ◽  
Jin Cao ◽  
Changgui Zhang ◽  
Liu Yang ◽  
Xiaojun Duan
Keyword(s):  
Achilles Tendon ◽  
Recurrence Rate ◽  
Operative Time ◽  
Achilles Tendon Rupture ◽  
Tendon Lengthening ◽  
Group A ◽  
Achilles Tendon Lengthening ◽  
The Mean ◽  
Group B

Background. Both percutaneous Achilles tendon lengthening by triple hemisection and the traditional open Z-lengthening are effective methods for Achilles tendon contracture. This study aims to evaluate the efficacy and safety of this new therapeutic method, which is based on the percutaneous sliding technique with three hemi-cuts in the tendon, as compared with the traditional open Z-lengthening. Methods. Retrospective analysis of the Achilles tendon contracture cases in our hospital between January 2010 and September 2016 was conducted. Twenty-five cases received percutaneous Achilles tendon lengthening (group A), and 30 patients who underwent open Z-lengthening during the same period were in the control group (group B). Operative time and hospital stay were statistically analyzed. Incision complication, equinus recurrence rate and Achilles tendon rupture morbidity were recorded. The function was assessed by American Orthopaedic Foot & Ankle Society (AOFAS) score. All cases in group A received Magnetic Resonance Imaging (MRI) of ankle preoperatively and in the follow-ups. Results. The mean follow-up period was 42.04 months in group A and 61.7 months in group B. The entire operative time and the mean hospitalization days were lower in group A than in group B. No incision and infection complication occurred in group A. The infection rate in group B was 3.3%. Equinus recurrence rate was 4% in group A and the equinus recurrence rate in group B was 21.4%. In group A, the mean AOFAS score increased from 64 ± 10.16 points preoperatively to 96.08 ± 3.17 at final follow-up, while the score in group B increased from 63.48 ± 6.2 points to 85.4 ± 10.3. MRI showed continuity of the Achilles tendon and homogeneous signal in group A. Conclusion. Modified surgery can significantly reduce the risk of Achilles tendon rupture, provide better balance in soft tissue strength between ankle dorsiflexion and ankle plantarflexion, helping to avoid recurrence of the deformity.

Surgical Anatomy and Accuracy of Percutaneous Achilles Tendon Lengthening

2006 ◽  
Vol 27 (6) ◽  
pp. 411-413 ◽  
Author(s):  
Michael L. Salamon ◽  
Stephen J. Pinney ◽  
Anthony Van Bergeyk ◽  
Scott Hazelwood
Keyword(s):  
Achilles Tendon ◽  
Surgical Anatomy ◽  
Tendon Lengthening ◽  
Achilles Tendon Lengthening

EFFECT OF ACHILLES TENDON LENGTHENING ON NEUROPATHIC PLANTAR ULCERS☆

2003 ◽  
Vol 85 (8) ◽  
pp. 1436-1445 ◽  
Author(s):  
MICHAEL J. MUELLER ◽  
DAVID R. SINACORE ◽  
MARY KENT HASTINGS ◽  
MICHAEL J. STRUBE ◽  
JEFFREY E. JOHNSON
Keyword(s):  
Achilles Tendon ◽  
Tendon Lengthening ◽  
Plantar Ulcers ◽  
Achilles Tendon Lengthening

scholarly journals The Role of Calcaneofibular Ligament (CFL) Injury in Ankle Instability

2017 ◽  
Vol 2 (3) ◽  
pp. 2473011417S0002
Author(s):  
Kenneth Hunt ◽  
Richard Fuld ◽  
Judas Kelley ◽  
Nicholas Anderson ◽  
Todd Baldini
Keyword(s):  
Contact Mechanics ◽  
Ankle Joint ◽  
Motion Capture ◽  
Contact Area ◽  
Subtalar Joint ◽  
Ankle Instability ◽  
Weight Bearing ◽  
Calcaneofibular Ligament ◽  
Tibiotalar Joint ◽  
Ankle Stability

Category: Ankle Introduction/Purpose: Acute inversion ankle sprains are among the most common musculoskeletal injuries. Higher grade sprains, which include anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) injury, can be particularly problematic and often require surgical repair. The implications of CFL injury on ankle instability are unclear. We aim to evaluate the impact of CFL injury on ankle stability and subtalar joint biomechanics. We hypothesized that CFL injury will result in decreased stiffness and torque, and alteration of ankle contact mechanics compared to the uninjured ankle in a cadaveric model. Methods: Twenty matched cadaveric ankles dissected of skin and subcutaneous tissue were mounted to an Instron with 20° of ankle plantar flexion and 15° of internal rotation. Intact specimens were axially loaded to body weight, then underwent inversion stress along the anatomic axis of the ankle from 0 to 20° (simulating inversion injury) for three cycles. ATFL and CFL were sequentially sectioned, and inversion testing repeated for each condition. Stiffness and change in torque were recorded using an Instron, and pressure and contact area were recorded using a calibrated Tekscan sensor system. Inversion angle of the talus and calcaneus relative to the ankle mortise were recorded using a three-dimensional motion capture system. Paired t tests were performed for inter and intra-group comparisons. Results: Stiffness and torque did not significantly decrease after sectioning of the ATFL, but did decreased significantly after sectioning of CFL. Peak pressures in the tibiotalar joint decreased significantly following CFL release compared to both the uninjured ankle and ATFL-only release. Mean contact area significantly increased following CFL release compared to both the uninjured ankle and ATFL release. There was a concentration of force in the anteromedial ankle joint during weight-bearing inversion. However, the center-of-force shifts 1.22 mm posteromedial after CFL release relative to an intact ankle. Motion capture showed a significant and sequential increase in inversion angle of both the calcaneus and talus, after release of each ligament. There was significantly more inversion in the subtalar joint than the tibiotalar joint with weight-bearing inversion. Conclusion: There is significantly lower stiffness and torque with weight-bearing inversion of the ankle joint complex following injury to both ATFL and CFL, and sequentially greater inversion of the talus and calcaneus with progressive ligament injury. This corresponds to a significant shift in the center of force in the tibiotalar joint. CFL contributes considerably to lateral ankle stability, and sprains that include CFL injury result in substantial alteration of contact mechanics at the ankle and subtalar joints. Repair of CFL may be beneficial during lateral ligament reconstruction, potentially mitigating long-term consequences (e.g., articular damage) of a loose or incompetent CFL.

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