Anatomic and Biomechanical Characteristics of the Ankle Joint and Total Ankle Arthroplasty

2005 ◽  
pp. 25-42
2017 ◽  
Vol 2 (3) ◽  
pp. 2473011417S0001
Author(s):  
Lawrence DiDomenico ◽  
Danielle Butto

Category: Ankle, Ankle Arthritis Introduction/Purpose: The purpose of this review is to present a case of post-traumatic ankle valgus and distal lateral tibial osteonecrosis successfully treated with staged deltoid repair, opening wedge tibial osteotomy, fibular lengthening, syndesmotic fusion and total ankle arthroplasty. Methods: Initial surgery consisted of ankle joint arthrotomy and deltoid imbrication. The second surgery consisted of a tibial opening wedge osteotomy with autogenous cortical fibular bone graft superior to the area of osteonecrosis to correct the 20 degree ankle valgus. Fibular lengthening osteotomy and fusion of the distal syndesmosis were also performed. CT scan confirmed bony consolidation at the distal tibiofibular syndesmosis as well as union of the allograft opening wedge. The final surgery was total ankle joint replacement with bone grafting of the area of osteonecrosis. Results: After 5 years of follow up the patient has progressed out of his AFO to full weightbearing. He reports no ankle pain, improved function and range of motion and is ambulating independently with no assistive devices. Conclusion: We successfully treated a case of distal lateral tibial osteonecrosis, and a 20 degree ankle valgus with staged deformity correction and ankle replacement. Radiographs demonstrate a well seated and positioned implant. We believe that with proper alignment that total ankle arthroplasty is a safe treatment option in the face of bone infarction.


2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0048
Author(s):  
Francesca E. Wade ◽  
Gregory Lewis ◽  
Andrea H. Horne ◽  
Lauren Hickox ◽  
Michael C. Aynardi ◽  
...  

Category: Ankle; Ankle Arthritis Introduction/Purpose: Deficits in ankle joint kinetics following total ankle arthroplasty (TAA) may be attributed to a reduction in the force-generating capacity of ankle joint muscles, but it is also important to consider the alterations to joint structure that may accompany this procedure. One key parameter indicative of joint structure with the potential to be influenced by TAA is the plantarflexion moment arm of the Achilles tendon (ATma). ATma is an indicator of the potential for the tendon force to produce plantarflexion moment that is determined by the three-dimensional line of action of the tendon relative to the ankle joint axis. The purpose of this study was to assess pre-to-post TAA changes in ATma; we hypothesized that pre- and post-TAA moment arms would not be different. Methods: We tested 10 TAA patients (age at surgery: 62.86 +- 9.72 y; height: 1.72 +- 0.08 m; body mass: 97.81 +- 20.89 kg) at pre-operative (˜ 1 mo pre) and post-operative (˜6 mo post) visits. All procedures involving testing of human subjects were approved by the Penn State Hershey Medical Center Institutional Review Board. ATma were measured using a method that combined ultrasound imaging of the tendon with 3D motion tracking of both the ultrasound probe and the ankle joint. The tendon and joint axis were located during trials in which the patients were seated with the knee extended while the ankle joint was voluntarily rotated in the sagittal plane. We also examined sagittal-plane weightbearing radiographs (pre- and post-op) to determine the AP distance from the center of the talar dome to the posterior margin of the calcaneus. Pre- and post-op ATma were compared using a paired t-test and regression. Results: No significant mean differences were found between post-op ATma and pre-op ATma (p = 0.360). Despite this, some patients were found to have large differences between pre- and postoperative ATma. For example, participants 1, 3, and 8 exhibited changes of -54.22%, +64.14% and +123.98% (pre-to-post) respectively (Figure 1). A moderate correlation between pre- and post-op ATma was found (r2 = 0.461, p = 0.031), indicating that only 46.1% of the variance in post-op ATma was explained by pre-op ATma (Figure 1). The normalized AP distance measured from the radiographs did not significantly change on average pre- to post-TAA (p = 0.561), and we found the change in this distance to correlate with the change in ATma (r2 = 0.370, p = 0.062). Conclusion: This is the first investigation of whether TAA alters ATma. Our results supported our hypothesis that pre-operative ATma predicts post-operative ATma. However, our hypothesis is supported only when the mean differences are considered, as there were sizeable differences for individuals. Despite a non-significant average change in ATma following TAA, at the individual level substantial changes in ATma were observed in seven of the 10 patients. Change in ATma was only partly explained by change in the AP position of the talar dome. Change in ATma has potential consequences for function in terms of ankle plantarflexor strength and walking velocity.


2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0030
Author(s):  
Robert Kulwin ◽  
Steven L. Haddad

Category: Ankle Arthritis; Other Introduction/Purpose: Talar and calcaneal height have been identified as important not only to the biomechanics of ankle joint function but of the adjacent joints of the hindfoot as well. Many proposed measurement systems have been introduced to the literature to assess talar height in ankle arthroplasty, but have significant shortcomings. The malleoli frequently develop osteophytes after total ankle arthroplasty. If the subtalar joint is fused or arthritic, methods relying on landmarks such as the angle of Gissane are similarly unreliable. Lastly, subsidence is often asymmetrical. Measuring from the highest point of the talar component may not be reflective of functional talar height. We propose using adjusted talocalcaneal height to assess the functional restoration of talar height. Methods: Pre and post-operative radiographs and weight bearing computed tomography (WBCT) were reviewed for 40 cases of failed total ankle arthroplasty undergoing revision. Bony landmarks were assessed for consistency over a time course of two to four years post operatively. Talocalcaneal height was measured along from the center of the tibial component of ankle arthroplasty on weight bearing lateral radiographs and on sagittal and coronal reconstructions on WBCT (fig 1). Measurements on radiographs and WBCT were compared for agreement. For implants where lateral radiographs could not be used (AgilityTM, Depuy), sagittal and coronal WBCT was used. Results: Average adjusted talocalcaneal height as measured on lateral radiographs, sagittal WBCT, coronal WBCT, and averaged values from sagittal and coronal WBCT was 68mm, 67.4mm, 68.5mm, and 68mm respectively. There was not a significant difference between the lateral radiographs and WBCT measurement methods (p= 0.30, 0.37, 0.46), and correlation was 0.99 for all methods. Measurements did not vary in cases of angular subsidence or subtalar fusion. Conclusion: Adjusted talocalcaneal height is a reproducible and reliable measurement to assess talar height. It accommodates procedures frequently performed in tandem with total ankle arthroplasty such as calcaneal osteotomy and subtalar fusion. It relies on a single, static bony landmark, and remains valid in cases of asymmetric subsidence. Lastly, it incorporates calcaneal height, which affects not only ankle joint mechanics but adjacent joint mechanics as well.


2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0010
Author(s):  
Guilherme Saito ◽  
Daniel Sturnick ◽  
Jonathan Deland ◽  
Scott Ellis ◽  
Constantine Demetracopoulos

Category: Ankle Arthritis Introduction/Purpose: Correct positioning of total ankle arthroplasty (TAA) implants has been associated with superior clinical outcomes. Furthermore, biomechanical studies have demonstrated that poor alignment of the components may lead to early component wear, compromising the longevity of the prosthesis. Malpositioning of TAA implants affects ligament engagement patterns and joint contact mechanics, possibly leading to altered joint kinematics. However, the correlation between implant position and ankle joint motion is still unclear. The objective of this study was to assess the effect of tibial component position on ankle kinematics following TAA during simulated gait. Methods: Eight mid-tibia cadaveric specimens were utilized in this IRB approved study. The stance phase of gait was simulated both pre- and post-TAA in each specimen using a six-degree of freedom robotic platform. Ground reaction forces and tibial kinematic from in vivo data were replicated while physiologic tendon force profiles were applied to each extrinsic ankle tendons by linear actuators instrumented. Ankle kinematics was measured from reflective markers attached to bones via surgical pins. TAAs were completed using a common fixed-bearing total ankle system following the manufacturer recommended protocol (Salto Talaris, Integra LifeSciences). Using reconstructed CT data, 3D tibial component position relative to a standard ankle joint reference was characterized (Figure 1A). The effect of tibial component position on absolute differences in ankle kinematics (pre – post TAA) was assessed using linear regression with a level of significance set to p = 0.05. Results: Differences in ankle joint kinematics were only identified in the transverse plane, where internal talar rotation was significantly increased following TAA compared to the native condition (Figure 1B). The medial position of TAA tibial components was found to be positively associated with increased internal talar rotation (Figure 1C; β = 1.861 degrees/mm, R2 = 0.72, p = 0.008). No other measurements of tibial component position (anterior-posterior/inferior-superior position, sagittal/frontal/transverse plane angle) were found to be significantly associated with altered ankle kinematics following TAA (All β < 0.1 and p > 0.05). Conclusion: This study suggests that medial positioning of the tibial implant affects ankle kinematics. During operative procedures the tibial component is usually positioned in order to preserve bone stock of the medial and lateral malleolus. However, little attention is given to the position of the implant in relation to the center of the tibial axis. This finding could have clinical implications for techniques implemented during surgical procedures and for the development of new instrumentation systems.


2020 ◽  
pp. 107110072097093
Author(s):  
Hyuck Sung Son ◽  
Jung Gyu Choi ◽  
Jungtae Ahn ◽  
Bi O Jeong

Background: In patients with end-stage varus ankle osteoarthritis (OA), hindfoot varus malalignment resulting from the varus deformity of the ankle joint is common. Although total ankle arthroplasty (TAA) performed to correct varus deformity of the ankle joint has the effect of correcting hindfoot alignment, no reports to date have described how much hindfoot alignment correction can be achieved. The purpose of this study was to identify correlation between ankle deformity correction and hindfoot alignment change after performing TAA in patients with end-stage varus ankle OA. Methods: A total of 61 cases that underwent TAA for end-stage varus ankle OA and followed up for at least 1 year were enrolled for this study. Correlation between changes of tibial-ankle surface angle (TAS), talar tilt (TT), and tibiotalar surface angle (TTS) and changes of hindfoot alignment angle (HA), hindfoot alignment ratio (HR), and hindfoot alignment distance (HD) measured preoperatively and at postoperative year 1 was analyzed. Results: TAS, TT, and TTS changed from 83.9 ± 4.1 degrees, 5.8 ± 5.0 degrees, and 78.1 ± 5.9 degrees, respectively, before operation to 89.2 ± 2.1 degrees, 0.4 ± 0.5 degrees, and 88.7 ± 2.3 degrees, respectively, after operation. HA, HR, and HD also changed from −9.2 ± 4.6 degrees, 0.66 ± 0.18, and −11.2 ± 6.9 mm to −3.7 ± 4.1 degrees, 0.48 ± 0.14, and −5.0 ± 5.3 mm. All the changes were statistically significant ( P < .001, respectively). The regression slope of correlation was 0.390 ( R2 = 0.654) between TTS and HA; 0.017 ( R2 = 0.617) between TTS and HR; and 0.560 ( R2 = 0.703) between TTS and HD. Conclusion: In patients with end-stage varus ankle OA, changes of hindfoot alignment could be predicted based on degree of ankle deformity corrected with TAA. Level of Evidence: Level IV, case series.


2020 ◽  
pp. 107110072097609
Author(s):  
Gun-Woo Lee ◽  
Hyoung-Yeon Seo ◽  
Dong-Min Jung ◽  
Keun-Bae Lee

Background: Modern total ankle arthroplasty (TAA) prostheses are uncemented press-fit designs whose stability is dependent on bone ingrowth. Preoperative insufficient bone density reduces initial local stability at the bone-implant interface, and we hypothesized that this may play a role in periprosthetic osteolysis. We aimed to investigate the preoperative bone density of the distal tibia and talus and compare these in patients with and without osteolysis. Methods: We enrolled 209 patients (218 ankles) who underwent primary TAA using the HINTEGRA prosthesis. The overall mean follow-up duration was 66 (range, 24-161) months. The patients were allocated into 2 groups according to the presence of periprosthetic osteolysis: the osteolysis group (64 patients, 65 ankles) and nonosteolysis group (145 patients, 153 ankles). Between the 2 groups, we investigated and compared the radiographic outcomes, including the Hounsfield unit (HU) value around the ankle joint and the coronal plane alignment. Results: HU values of the tibia and talus measured at 5 mm from the reference points were higher than those at 10 mm in each group. However, comparing the osteolysis and nonosteolysis groups, we found no significant intergroup difference in HU value at every measured level in the tibia and talus ( P > .05). Concerning the coronal plane alignment, there were no significant between-group differences in the tibiotalar and talar tilt angles ( P > .05). Conclusions: Patients with osteolysis showed similar preoperative bone density of the distal tibia and talus compared with patients without osteolysis. Our results suggest that low bone density around the ankle joint may not be associated with increased development of osteolysis. Level of Evidence: Level III, retrospective cohort study.


2019 ◽  
Vol 4 (4) ◽  
pp. 247301141988435
Author(s):  
Thos Harnroongroj ◽  
Amelia Hummel ◽  
Scott J. Ellis ◽  
Carolyn M. Sofka ◽  
Kristin C. Caolo ◽  
...  

Background: Restoring the joint line is an important principle in total knee arthroplasty. However, the effect of joint line level on patient outcomes after total ankle arthroplasty (TAA) remains unclear, as there is no established method for measuring ankle joint level in TAA. The objective of this study was to develop a reliable radiographic ankle joint line measurement method and to compare ankle joint line level measured pre-TAA, post-TAA, and in nonarthritic ankles. Methods: A total of 112 radiographic sets were analyzed. Each set included weightbearing anteroposterior radiographs of the operative ankle taken preoperatively, 1-year postoperatively, and of the contralateral ankle. Measurements of vertical intermalleolar distance (VIMD) and vertical joint line distance (VJLD) at pre-TAA, post-TAA, and of the contralateral ankle were recorded by 2 authors on 2 separate occasions. The ratio of VJLD to VIMD was defined as the joint line height ratio (JLHR). Reliability of measurements and correlation between VIMD and VJLD were assessed. Pre-TAA, nonarthritic contralateral ankle, and post-TAA JLHR were compared and considered significantly different if P <.05. Results: The inter- and intrarater reliability of radiographic measurements was excellent ( r > 0.9). There were strong positive correlations of VIMD and VJLD, r = 0.809 (pre-TAA)/0.756 (post-TAA), P < .001. Mean (SD) pre-TAA, nonarthritic contralateral ankle, and post-TAA JLHRs were 1.54 (0.31), 1.39 (0.26), and 1.62 (0.49), respectively. Pre- and post-TAA JLHRs were significantly higher compared to the nonarthritic contralateral ankle ( P < .05). JHLR was not significantly different between pre- and post-TAA ( P = .15). Conclusion: The JLHR was reliable and could be a clinically applicable method for assessing ankle joint line level in patients undergoing TAA. End-stage ankle arthritis demonstrated elevated joint line level compared with nonarthritic ankles, and the joint line level post-TAA remained elevated compared with nonarthritic ankles. Further studies are needed to understand the effect of joint line elevation on clinical outcomes after TAA. Level of Evidence: Level III, retrospective comparative study.


Author(s):  
Yanwei Zhang ◽  
Zhenxian Chen ◽  
Hongmou Zhao ◽  
Xiaojun Liang ◽  
Cheng Sun ◽  
...  

In vivo load and motion in the ankle joint play a key role in the understanding of the failure mechanism and function outcomes of total ankle arthroplasty. However, a thorough understanding of the biomechanics of the ankle joint in daily activities is lacking. The objective of this study was to develop a novel lower extremity musculoskeletal multibody dynamics model with total ankle arthroplasty considering the 6 degrees of freedom of the ankle joint motions and the deformable contact mechanics of the implant, based on force-dependent kinematics method. A patient who underwent total ankle arthroplasty surgery was considered. The walking gait data of the patient was measured in a gait laboratory and used as the input for the patient-specific musculoskeletal modeling. The predictions from the musculoskeletal model of total ankle arthroplasty included dorsiflexion–plantar flexion, inversion–eversion, internal–external rotation, anterior–posterior translation, inferior–superior translation, and medial–lateral translation of the tibiotalar joint, the ankle contact forces, the muscle activations, and the ligament forces. The magnitudes and tendencies of the predicted results were all within reasonable ranges, as compared with the data available in the literature. The predicted peak total ankle contact force was 6.55 body weight. In addition, the peak contact forces of the lateral and medial compartments were 4.22 body weight and 2.59 body weight, respectively. This study provides a potential new platform for the design of a better ankle prosthesis, the improvement of the operation techniques of the clinicians, and the accelerated postoperative recovery of the patients.


2019 ◽  
Vol 13 (Supl 1) ◽  
pp. 63S
Author(s):  
Guilherme Honda Saito ◽  
Daniel Sturnick ◽  
Jonathan Deland ◽  
Scott Ellis

Introduction: Correct positioning of total ankle arthroplasty (TAA) implants has been associated with superior clinical outcomes. However, the correlation between implant position and ankle motion is unclear. The objective of this study was to assess the effect of tibial component position on ankle kinematics during simulated gait. Methods: The stance phase of gait was simulated pre and post-TAA with 8 mid-tibia cadaveric specimens using a six-degrees-of-freedom robotic platform. Ankle kinematics were measured based on reflective markers. A fixed-bearing total ankle system (Salto Talaris, Integra LifeSciences) was used. Using reconstructed CT data, the 3D tibial component position relative to a standard ankle joint reference was characterized (Fig 1A). The effect of the tibial component position on absolute differences in ankle kinematics (pre/post TAA) was assessed using linear regression with a level of significance set to p = 0.05. Results: Differences in ankle joint kinematics were only identified in the transverse plane, where internal talar rotation was significantly increased following TAA compared with the native condition (Fig 1B). The medial position of TAA tibial components was positively associated with increased internal talar rotation (Fig 1C; β = 1.861 degrees/mm, R2 = 0.72, p = 0.008). Conclusion: This study suggests that a medial-lateral position of the tibial implant affects ankle kinematics. During operative procedures, the tibial component is usually positioned to preserve the bone stock of the medial and lateral malleolus. However, little attention is given to the position of the implant in relation to the center of the tibial axis. This finding could have clinical implications for techniques.


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