OBJECTIVE: Subtalar arthroereisis is a procedure commonly performed in children with flat feet. The procedure is performed when conservative treatment did not have the desired effect,or when the patient\'s abnormal symptoms are very severe and make it difficult for them to function normally in daily life. The aim of this study was to assess whether subtalar arthroereisis and physiotherapy improve the quality of life among children with flat feet.
METHODS: The study comprised 79 patients (140 operated feet) diagnosed with a flat foot defect who underwent a subtalar arthroereisis procedure. A self-administered questionnaire and a shortened version of the standardised WHOQOL-BREF questionnaire were used in the research.
RESULTS: The study confirmed that the patients\' quality of life after surgery was high in all the areas regarding the somatic, psychological, social and environmental domains. In the group of children assessed 13-24 months after surgery. it was also found that rapid fatigue after exercise (30% ± 9%) and Achilles tendon contracture (7% ± 4%) were significantly reduced. The results of the study confirmed that subtalar arthroereisis contributes to a decreased demand for orthoses in children (9% ± 6%) and for orthopaedic footwear (11% ± 5%) than before surgery.
CONCLUSIONS: The employment of subtalars arthroereisis has a positive effect on the quality of life of children with flat feet. The surgery contributes to a reduction in pain and other abnormal symptoms that are associated with flat feet. In addition, physiotherapy performed after the procedure had a positive effect on the healing process and contributed to the improvement of the children\'s quality of life.

Background and Objectives: Despite the established role of subtalar joint arthrodesis (SJA) for treatment of subtalar osteoarthritis, achieving bone union remains challenging, with up to 46% non-union rates. Adequate compression and stable fixation are crucial for successful outcomes, with internal screw fixation being the gold standard for SJA. The delta configuration, featuring highly divergent screws, offers stability, however, it can result in hardware irritation in 20-30% of patients. Solutions to solve this complication include cannulated compression screw (CCS) countersinking or cannulated compression headless screw (CCHS) application. The aim of this biomechanical study was to investigate the stability of a delta configuration for SJA utilizing either a combination of a posterior CCHS and an anterior CCS or a standard two-CCS combination. Materials and Methods: Twelve paired human cadaveric lower legs were assigned pairwise to two groups for SJA using either two CCSs (Group 1) or one posterior CCHS and one anterior CCS (Group 2). All specimens were tested under progressively increasing cyclic loading to failure, with monitoring of the talocalcaneal movements via motion tracking. Results: Initial stiffness did not differ significantly between the groups, p = 0.949. Talocalcaneal movements in terms of varus-valgus deformation and internal-external rotation were significantly bigger in Group 1 versus Group 2, p ≤ 0.026. Number of cycles until reaching 5° varus-valgus deformation was significantly higher in Group 2 versus Group 1, p = 0.029. Conclusions: A delta-configuration SJA utilizing a posterior CCHS and an anterior CCS is biomechanically superior versus a standard configuration with two CCSs. Clinically, the use of a posterior CCHS could prevent protrusion of the hardware in the heel, while an anterior CCS could facilitate less surgical time and thus less complication rates.

Medial displacement calcaneal osteotomy (MDCO) is the standard procedure for flatfoot. We investigated the effect of MDCO on the foot using a finite element analysis. Foot models were created from computed tomography data of 8 patients with flat feet. MDCO was performed on each model with bone translation distance of 4, 8, and 12 mm. The morphological changes, plantar pressures, and stress percentage on the talocrural and subtalar joints were evaluated before and after surgery. Morphological evaluation showed improvement in the medial longitudinal arch. The stress percentage of plantar pressure in the medial area decreased, and the stress percentage of plantar pressure in the mid- and lateral forefoot area increased. At the talocrural joint, the medial and middle stress percentage increased, while the lateral and posterior stress percentage decreased. In the subtalar joint, the stress percentage in the middle subtalar joint increased and that in the posterior subtalar joint decreased. Within the posterior subtalar joint, the anterior and medial stress percentage increased, while the posterior and lateral stress percentage decreased. Preoperative simulation using the finite element analysis may be useful in understanding postoperative morphological changes and loading conditions to perform patient-specific surgery.

UNASSIGNED: To compare radiographic union and clinical outcomes between parallel and angulated screw configurations (SCs) for patients undergoing subtalar arthrodesis due to posttraumatic subtalar arthritis (PSA) after displaced intra-articular calcaneal fractures.
UNASSIGNED: This study retrospectively reviewed 140 consecutive PSA cases from March 2011 to November 2021 (parallel SC: group 1, n = 80; angulated SC: group 2, n = 60). Radiographic union, Foot and Ankle Outcome Score (FAOS), and visual analog scale (VAS) scores were among the outcome assessments. Six months after surgery, nonunion was confirmed based on plain radiographs, clinical evaluation, and computed tomography.
UNASSIGNED: Groups 1 and 2 included 14 (17.5%) and 3 (5.0%) nonunion cases, respectively (p = 0.035). There was no significant difference in preoperative FAOS and VAS scores between the groups. However, group 2 had significantly better clinical outcomes in 2 of the 5 FAOS domains (sports and quality of life), as well as VAS scores at 3 and 6 months postoperatively and at the final follow-up (p < 0.05).
UNASSIGNED: Using the angulated SC for PSA had a lower nonunion rate and superior clinical outcomes than the parallel SC. Obtaining better radiological and clinical outcomes when using the angulated SC, rather than the parallel SC, would be advantageous.

Fracture of the lateral process of the talus (FLPT) is uncommon in clinical practice and can be easily missed or misdiagnosed. In recent years, as researchers from all over the world have further deepened their research on FLPT, there has been a breakthrough in the classification, and the methods and principles of clinical management have changed accordingly; however, there is still no standardized guideline for the diagnosis and management of FLPT, and there have been few relevant literature review articles related to this kind of fracture in the past at least 5 years. In this article, we review the clinical classification, classification-based therapeutic recommendations, and prognosis of FLPT, with the aim of providing a reference for the clinical diagnosis and management of this infrequent fracture.

BACKGROUND: The use of subtalar arthroereisis as an adjunct to the surgical treatment of stage 1 flexible progressive collapsing foot deformity (PCFD) is controversial. The aim was to investigate the clinical outcomes and report the implant removal rate of subtalar arthroereisis as an adjunct for stage 1 PCFD.
METHODS: A retrospective study of 212 consecutive feet undergoing operative management of stage 1 PCFD with adjunctive subtalar arthroereisis between October 2010 and April 2018. The primary outcome was the Foot and Ankle Outcome Score (FAOS). Secondary outcomes included Foot and Ankle Disability Index (FADI), Euroqol-5D-5L Index and implant removal rate.
RESULTS: Post-operative clinical FAOS outcomes were collected for 153 feet (72.2%). At mean 2.5-year follow-up, the mean ± standard deviation FAOS for each domain was as follows; Pain: 81.5 ± 18.5, Symptoms: 79.5 ± 12.9, Activities of Daily Living: 82.5 ± 15.4 and Quality of Life: 64.2 ± 23.7. EQ-5D-5L Index was 0.884 ± 0.152. Pre-operative scores were available for 20 of these feet demonstrating a statistically significant improvement in all FAOS, FADI and EQ-5D-5L domains (p < 0.05). The implant removal rate for persistent sinus tarsi pain was 48.1% (n = 102).
CONCLUSIONS: Use of a subtalar arthroereisis implant as an adjunct to conventional procedures in stage 1 flexible PCFD can result in significant improvement in pain and function. Patients should be counselled as to the relatively frequent rate of subsequent implant removal.
METHODS: IV.

The interaction among joints of the midtarsal complex and subtalar joint is important for locomotor function; however, its complexity poses substantial challenges in quantifying the joints\' motions. We determine the mobility of these joints across locomotion tasks and investigate the influence of individual talus morphology on their motion. Using highly accurate biplanar videoradiography, three-dimensional bone kinematics were captured during walking, running and hopping. We calculated the axis of rotation of the midtarsal complex and subtalar joint for the landing and push-off phases. A comparison was made between these rotation axes and the morphological subtalar axis. Measurement included total rotation about and the orientation of the rotation axes in the direction of the subtalar joint and its deviation via spatial angles for both phases. The rotation axes of all three bones relative to the talus closely align with the morphological subtalar axis. This suggests that the midtarsal and subtalar joints\' motions might be described by one commonly oriented axis. Despite having such an axis, the location of the axes and ranges of motion differed among the bones. Our results provide a novel perspective of healthy foot function across different sagittal plane-dominant locomotion tasks underscoring the importance of quantifying midtarsal complex and subtalar motion while accounting for an individual\'s talus morphology.

BACKGROUND: The talocrural joint and the subtalar joint are the two major joints of the ankle-joint complex. The position and direction of the exosuit force line relative to these two joint axes can influence ankle motion. We aimed to understand the effects of different force-lines on ankle multidimensional motion.
METHODS: In this article, three assistance force line schemes for ankle exosuits were proposed: perpendicular to the talocrural joint axis (PT), intersecting with the subtalar joint axis (IS), and parallel to the triceps surae (PTS). A theoretical model was proposed to calculate the exosuit\'s assistance moment. Seven participants completed four experimental tests of ankle plantarflexion, including three passive motions assisted by the PT, PTS and IS schemes, and one active motion without exosuit assistance (Active).
RESULTS: The simulation results demonstrated that all three exosuits were able to produce significant moments of ankle plantarflexion. Among these, the PT scheme exhibited the highest moments in all dimensions, followed by the PTS and IS schemes. The experimental findings confirmed the effectiveness of all three exosuit schemes in assisting ankle plantarflexion. Additionally, as the assistive force lines approached the subtalar joint, there was a decrease in ankle motion assisted by the exosuits in non-plantarflexion directions, along with a reduction in the average distance of ankle angle curves relative to active ankle motion. Furthermore, the linear correlation coefficients between inversion and plantarflexion, adduction and plantarflexion, and adduction and inversion gradually converged toward active ankle plantarflexion motion.
CONCLUSIONS: Our research indicates that the position of the exosuit force line to the subtalar joint has a significant impact on ankle inversion and adduction. Among all three schemes, the IS, which has the closest distance to the subtalar joint axes, has the greatest kinematic similarity to active ankle plantarflexion and might be a better choice for ankle assistance and rehabilitation.

Subtalar dislocations, ankle dislocations, and total talar dislocations are high-energy injuries. As such, there may be associated osseous or soft tissue injuries that can be diagnosed with advanced imaging such as computed tomography (CT) or MRI. With closed injuries, closed reduction may require sedation or general anesthesia, flexion of the knee to release the tension of the gastrocnemius-soleus complex, distraction is applied, the deformity is accentuated, then the deformity is corrected. Open injuries are usually associated with a higher level of energy and a higher rate of infection. It is important to thoroughly irrigate and debride open dislocations both before and after reduction.

BACKGROUND: Osteochondral lesions on the lateral process of the talus involving the subtalar joint are rare; the optimal surgical treatment remains to be clarified as there are few reports. Additionally, bilateral cases are extremely rare. Therefore, the clinical outcomes of the surgical treatment for bilateral osteochondral lesions on the lateral process of the talus involving the subtalar joint have not been fully elucidated.
METHODS: A 16-year-old boy who played soccer presented to our hospital with bilateral hindfoot pain. The symptoms persisted even after 3 months of conservative treatment. The patient and family requested surgical treatment to relieve the symptoms.
METHODS: The patient was diagnosed with bilateral osteochondral lesions on the lateral process of the talus, involving the subtalar joint based on computed tomography and magnetic resonance imaging findings.
METHODS: Arthroscopic debridement and microfracture were performed bilaterally.
RESULTS: Postoperative computed tomography and magnetic resonance imaging of both feet revealed remodeling of the subchondral bone. The patient returned to play at the pre-injury level with no pain.
CONCLUSIONS: This report describes a case of bilateral osteochondral lesions on the lateral process of the talus, involving the subtalar joint. Arthroscopic debridement and microfracture were effective in relieving symptoms and the subchondral bone remodeling. To the best of our knowledge, this is the first report of arthroscopic treatment of osteochondral lesions of the lateral process of the talus involving the subtalar joint.