Biomechanical stress analysis of the main soft tissues associated with the development of adult acquired flatfoot deformity

Background: Adult acquired flatfoot deformity (AAFD) is traditionally related to a tibialis posterior tendon deficiency. In the intermediate stages, treatments are commonly focused on reinforcing this tissue, but sometimes the deformation appears again over time, necessitating the use of more aggressive options. Tissue stress cannot be consistently evaluated through traditional experimental trials. Computational foot modeling extends knowledge of the disease and could help guide the clinical decisions. This study analyzes the biomechanical stress of the main tissues related to AAFD and their capacity to support the plantar arch. Methods: A FE foot model was reconstructed. All the bones, cartilages and tissues related to AAFD were included, respecting their biomechanical characteristics. The biomechanical tissue stress was quantified. The capacity of each soft tissue to support the plantar arch was measured, following clinical criteria. Findings: Biomechanical stress of the tibialis posterior tendon is considerably superior to both the plantar fascia and spring ligament stress. However, it cannot maintain the plantar arch by itself. Both the tibialis posterior tendon and spring ligament act in reducing the hindfoot pronation, while the plantar fascia is the main tissue that prevents arch elongation. The Achilles tendon action increases the plantar tissue stress. Interpretation: The tibialis posterior tendon stress increases when the spring ligament or the fascia plantar fails. These findings are consistent with the theory that regards the tibialis posterior tendon as a secondary actor because it cannot support the plantar arch and claudicates when the hindfoot has rotated around the talonavicular joint

Analysis of biomechanical stresses caused by hindfoot joint arthrodesis in the treatment of adult acquired flatfoot deformity: A finite element study

Background: Treatments of adult acquired flatfoot deformity in early stages (I–IIa–IIb) are focused on strengthening tendons, in isolation or combined with osteotomies, but in stage III, rigidity of foot deformity requires more restrictive procedures such as hindfoot joint arthrodesis. Few experimental studies have assessed the biomechanical effects of these treatments, because of the difficulty of measuring these parameters in cadavers. Our objective was to quantify the biomechanical stress caused by both isolated hindfoot arthrodesis and triple arthrodesis on the main tissues that support the plantar arch. Methods: An innovative finite element model was used to evaluate some flatfoot scenarios treated with isolated hindfoot arthrodesis and triple arthrodesis. Results and conclusions: When arthrodeses are done in situ, talonavicular seems a good option, possible superior to subtalar and at least equivalent to triple. Calcaneocuboid arthrodesis reduces significantly both fascia plantar and spring ligament stresses but concentrates higher stresses around the fused joint

Biomechanical effects of medializing calcaneal osteotomy on bones and the tissues related to adult-acquired flatfoot deformity: a computational study

Medializing calcaneal osteotomy (MCO) is a flatfoot treatment in stages IIa–IIb. It is true that structural correction is well known, but stress changes in foot tissues have not been sufficiently studied to date. Our objective was to evaluate the stress generated by MCO in both hindfoot and forefoot bones and in some soft tissues that support the arch. A finite element foot model was employed, simulating some situations related to flatfoot development. Results show a higher stress concentration around the osteotomy region when MCO is used in patients with plantar fascia weakness. Additionally, the stress increase found in lateral metatarsals would be the explanation for the long-term pain reported by patients

Effectiveness of the Lapidus plate system in foot surgery: APRISMA compliant systematic review

[Abstract] Lapidus arthrodesis is an established standard procedure to correct various footsurgery problems and hallux limitus, hypermobility of the first ray, halluxabductus valgus, and symptomatic lesser metatarsal. After decades, many fixa-tion methods in the orthopaedic surgery industry have been developed fordecreasing complications and improving this technique. The aim of this PRI-SMA compliant systematic review is to analyse the effectiveness of several lapi-dus plate systems in foot surgery. We have carried out the first systematicreview of the relevant published literature so as to systematically evaluate thescientific knowledge available now on this association, assigning predefined eli-gibility criteria. Fourteen studies were selected which had an overall of 738cases. The first tarsal metatarsal joint and hallux valgus were treated by theapplication of different types of Lapidus plate system. The optimal level of thefixation in these procedures is related with the type and system insertion placeof the plate with or without screw in each specific foot disease. There is an insuf-ficient number of studies about the effectiveness of the different types of Lapidusplate system in foot surgery, and there is a need to increase outcomes knowledgeon the level of the fixation, sort of the system, and insert place in foot surgery

Effectiveness of calcaneal osteotomy in surgical treatment of foot conditions: A Prisma statement guidelines compliant systematic review

[Abstract] Calcaneal osteotomy is a commonly established method used to correct various foot malalignment surgery problems that produce varus and valgus hindfoot abnormality as well as Haglund's deformity, cavovarus foot reconstruction, flatfoot deformity, plantar fasciitis, posterior tibial tendon insufficiency and planovalgus foot. After decades, several procedures in orthopaedic foot surgery have been suggested for reducing the risk of wound and neurovascular complications. The goal of this Prisma statement guidelines compliant systematic review was to establish the effectiveness and safety of calcaneal osteotomy in foot surgery. We have performed a novel systematic review of the current published literature in order to evaluate the scientific evidence now available on this association, assigning predefined exclusion and inclusion criteria. Eight investigations were selected which had 191 cases. The adult flatfoot, tibialis posterior reconstruction and cavovarus foot deformity were treated with different procedures of calcaneal osteotomy techniques. The adequate level of effectiveness of calcaneal osteotomy is associated with the kind and location of the incision, with or without screw application, in each specific foot condition. There is a limited number of scientific investigations of the effectiveness and safety of the different kinds of calcaneal osteotomy in foot surgery, and there is the need to enhance outcome knowledge on this foot surgery technique

Low-dose prophylaxis protocol for heterotopic ossification after hip preservation surgery in a sport participants cohort

Background: Heterotopic ossification (HO) is a well-known complication of arthroscopic and open surgical treatment of femoroacetabular impingement (FAI). Incidence of heterotopic ossification has been reported in the literature between 0% and 44% after hip arthroscopy and between 18.2% and 25% after anterior mini-open surgery. Currently, pharmacological prophylaxis with NSAIDs and selective COX-2 inhibitors are commonly used and their effectiveness is well documented in literature. Hypothesis: We hypothesized that the low-dose prophylaxis protocol with selective cox-2 inhibitors decreases the risk of heterotopic ossification in open or arthroscopic hip preservation surgery in athletes. Methods: This study is an analysis of prospectively gathered data on 98 sport participant patients who underwent arthroscopic or anterior mini-open treatment for FAI between April 2008 and April 2018. All the patients received postoperative oral prophylaxis with 60 mg etoricoxib once daily for two weeks. Post-operative X-rays were performed at 1, 3, and 12 months after surgery and reviewed by two orthopedic surgeons blinded to the type and side of surgery. HO were graded according to the Brooker classification. Descriptive statistics was used to analyze demographic data. Bivariate analysis was performed to analyze the association of HO with each of the following variables: type of surgery, physical activity, time of evolution of symptoms, age at surgery, and sex. Finally, a regression model analysis was performed to determine the presence of confounding effects between variables. Results: The study cohort was composed of 54 patients in the arthroscopic treatment group and 44 patients in the anterior mini-open group. HO was identified in 6 (13.6%) patients in the mini-open group. No HO was identified in the arthroscopic group. In the bivariate analysis, “type of surgery” was the only variable that showed a statistically significant association with HO (p = 0.007). Conclusion: Results of this study suggest that anterior mini-open treatment was characterized by a higher risk of HO development compared to hip arthroscopy for femoroacetabular impingement treatment regardless of pharmacological prophylaxis. The treatment regimen of 60 mg etoricoxib daily for two weeks was an effective prophylaxis for HO formation in sport participant patients compared with data available in the literature

Arthroscopic Proximal Row Carpectomy Using the Volar Central Portal

Proximal row carpectomy (PRC) is a well-accepted procedure for the treatment of degenerative lesions of the wrist and advance Kienböck disease. This procedure has been classically described as an open procedure but recently has been reported as an arthroscopic one. Arthroscopic PRC has several advantages such as minimal damage to the dorsal and volar ligaments as well as there being no need to detach the capsule, which can facilitate earlier mobilization and can decrease postoperative stiffness. In addition, there is a reduced risk of the interosseous posterior nerve being injured, and the proprioception system continues to function.This arthroscopically assisted technique uses the volar central portal as a third portal, which can be useful to remove the volar portions of the bones to view the dorsal areas of the bones and to allow the surgeon to work with 2 instruments at the same time. As a result, the time spent on the procedure can be reduced

Low-dose prophylaxis protocol for heterotopic ossification after hip preservation surgery in a sport participants cohort

Background: Heterotopic ossification (HO) is a well-known complication of arthroscopic and open surgical treatment of femoroacetabular impingement (FAI). Incidence of heterotopic ossification has been reported in the literature between 0% and 44% after hip arthroscopy and between 18.2% and 25% after anterior mini-open surgery. Currently, pharmacological prophylaxis with NSAIDs and selective COX-2 inhibitors are commonly used and their effectiveness is well documented in literature. Hypothesis: We hypothesized that the low-dose prophylaxis protocol with selective cox-2 inhibitors decreases the risk of heterotopic ossification in open or arthroscopic hip preservation surgery in athletes. Methods: This study is an analysis of prospectively gathered data on 98 sport participant patients who underwent arthroscopic or anterior mini-open treatment for FAI between April 2008 and April 2018. All the patients received postoperative oral prophylaxis with 60 mg etoricoxib once daily for two weeks. Post-operative X-rays were performed at 1, 3, and 12 months after surgery and reviewed by two orthopedic surgeons blinded to the type and side of surgery. HO were graded according to the Brooker classification. Descriptive statistics was used to analyze demographic data. Bivariate analysis was performed to analyze the association of HO with each of the following variables: type of surgery, physical activity, time of evolution of symptoms, age at surgery, and sex. Finally, a regression model analysis was performed to determine the presence of confounding effects between variables. Results: The study cohort was composed of 54 patients in the arthroscopic treatment group and 44 patients in the anterior mini-open group. HO was identified in 6 (13.6%) patients in the mini-open group. No HO was identified in the arthroscopic group. In the bivariate analysis, “type of surgery” was the only variable that showed a statistically significant association with HO (p = 0.007). Conclusion: Results of this study suggest that anterior mini-open treatment was characterized by a higher risk of HO development compared to hip arthroscopy for femoroacetabular impingement treatment regardless of pharmacological prophylaxis. The treatment regimen of 60 mg etoricoxib daily for two weeks was an effective prophylaxis for HO formation in sport participant patients compared with data available in the literature

Numerical modelling of cancellous bone damage using an orthotropic failure criterion and tissue elastic properties as a function of the mineral content and microporosity.

[EN] Background and objective : Elastic and strength properties of lamellar tissue are essential to analyze the mechanical behaviour of bone at the meso- or macro-scale. Although many effort s have been made to model the architecture of cancellous bone, in general, isotropic elastic constants are assumed for tissue modelling, neglecting its non-isotropic behaviour. Therefore, isotropic damage laws are often used to esti- mate the bone failure. The main goals of this work are: (1) to present a new model for the estimation of the elastic properties of lamellar tissue which includes the bone mineral density (BMD) and the micro- porosity, (2) to address the numerical modelling of cancellous bone damage using an orthotropic failure criterion and a discrete damage mechanics analysis, including the novel approach for the tissue elastic properties aforementioned. Methods : Numerical homogenization has been used to estimate the elastic properties of lamellar bone considering BMD and microporosity. Microcomputed Tomography ( ¿-CT) scans have been performed to obtain the micro-finite element ( ¿-FE) model of cancellous bone from a vertebra of swine. In this model, lamellar tissue is orientated by considering a unidirectional layer pattern being the mineralized colla- gen fibrils aligned with the most representative geometrical feature of the trabeculae network. We have considered the Hashin¿s failure criterion and the Material Property Degradation (MPDG) method for sim- ulating the onset and evolution of bone damage. Results: The terms of the stiffness matrix for lamellar tissue are derived as functions of the BMD and mi- croporosity at tissue scale. Results obtained for the apparent yield strain values agree with experimental values found in the literature. The influence of the damage parameters on the bone mechanics behaviour is also presented. Conclusions : Stiffness matrix of lamellar tissue depends on both BMD and microporosity. The new ap- proach presented in this work enables to analyze the influence of the BMD and porosity on the mechan- ical response of bone. Lamellar tissue orientation has to be considered in the mechanical analysis of the cancellous bone. An orthotropic failure criterion can be used to analyze the bone failure onset instead of isotropic criteria. The elastic property degradation method is an efficient procedure to analyze the failure propagation in a 3D numerical model.The authors acknowledge the Ministerio de Ciencia e Innovacion and the European Regional Development Fund (FEDER) for the financial support received through the projects PID2020-118920RB-I00 and PID2020-118480RB-C21, the Generalitat Valenciana for Plan FDGENT 2018 and Programme PROMETEO 2021/046.Megías-Díaz, R.; Vercher Martínez, A.; Belda, R.; Peris Serra, JL.; Larrainzar-Garijo, R.; Giner Maravilla, E.; Fuenmayor Fernández, F. (2022). Numerical modelling of cancellous bone damage using an orthotropic failure criterion and tissue elastic properties as a function of the mineral content and microporosity. Computer Methods and Programs in Biomedicine. 219:1-17. https://doi.org/10.1016/j.cmpb.2022.10676411721