Dynamic subtalar joint space measurement analysis following tibiotalar arthrodesis and total ankle replacement.

Background: Tibiotalar arthrodesis and total ankle replacement are current standards for treating end-stage ankle osteoarthritis. Our clinical understanding of biomechanical causes and risk factors for subtalar secondary osteoarthritis development following surgical treatment is limited. The objective of this retrospective study was to investigate subchondral bone morphometric differences of individuals treated with a tibiotalar arthrodesis or ankle arthroplasty that may influence subtalar joint measurements during overground walking; results were compared between surgical groups, their unaffected limb, and asymptomatic controls.

Talar Morphology of Charcot-Marie-Tooth Patients With Cavovarus Feet.

Background: Charcot-Marie-Tooth disease (CMT), a common inherited neurologic disorder, significantly impacts the morphology of foot bones, particularly the talus. The disease has been classified into types based on specific mutations, with the most common being CMT type 1 (CMT1; demyelinating) and CMT type 2 (CMT2; axonal). However, the specific osseous morphologic variations in CMT patients and their major genetic subgroups remain insufficiently understood, posing challenges in clinical management and surgical intervention.

Standardizing 3 Dimensional Measurements in Foot and Ankle Imaging: A Contemporary Review and Methodological Proposal.

Increasing utilization of weight-bearing computed tomography and fluoroscopy has driven the need for standardization of 3 dimensional (3D) measurements in the foot and ankle. These emerging imaging modalities are currently used to evaluate foot and ankle conditions including ankle osteoarthritis, progressive collapsing foot deformity, midfoot instability, and hallux valgus. This study aims first to provide a comprehensive review of clinical studies that have utilized these 3D methodologies.

Cadaveric validation of markerless tracking using weightbearing computed tomography versus conventional computed tomography imaging techniques.

This study aimed to validate the use of weightbearing computed tomography against conventional computed tomography and against bead tracking for markerless tracking of key foot and ankle bones. A left cadaveric limb was implanted with tantalum beads and underwent conventional computed tomography and weightbearing computed tomography scanning, followed by biplane fluoroscopy motion capture to simulate gait. Bone models from conventional computed tomography and weightbearing computed tomography were compared for surface differences and kinematic analysis across six joints.

Ankle osteoarthritis: Toward new understanding and opportunities for prevention and intervention.

The ankle infrequently develops primary osteoarthritis (OA), especially when compared to the hip and the knee. Ankle OA instead generally develops only after trauma. The consequences of end-stage ankle OA can nonetheless be extremely debilitating, with impairment comparable to that of end-stage kidney disease or congestive heart failure.

Recommendation of minimal distal tibial length for long axis coordinate system definitions.

Accurate anatomical coordinate systems for the foot and ankle are critical for interpreting their complex biomechanics. The tibial superior-inferior axis is crucial for analyzing joint kinematics, influencing bone motion analysis during gait using CT imaging and biplane fluoroscopy. However, the lack of consensus on how to define the tibial axis has led to variability in research, hindering generalizability.

Static posture weightbearing joint angle differences in patients with varus ankle osteoarthritis.

Background: Advanced varus ankle osteoarthritis is a debilitating disease that can present with limited physical function, severe pain, and diminished quality of life. Weightbearing computed tomography enables submillimeter 3-dimensional visualization, computational analyses, and enhanced diagnoses in reporting complex degenerative changes more accurately.

Research Question: This study set to compare static posture weightbearing joint angle differences in healthy and varus ankle osteoarthritis patients (compensated and non-compensated).

Quantitative Skeletal Imaging and Image-Based Modeling in Pediatric Orthopaedics.

Purpose Of Review: Musculoskeletal imaging serves a critical role in clinical care and orthopaedic research. Image-based modeling is also gaining traction as a useful tool in understanding skeletal morphology and mechanics. However, there are fewer studies on advanced imaging and modeling in pediatric populations.

Automatic anatomical foot and ankle coordinate toolbox.

Accurate analysis of bone position and orientation in foot and ankle studies relies on anatomical coordinate systems (ACS). Reliable ACSs are necessary for many biomechanical and clinical studies, especially those including weightbearing computed tomography and biplane fluoroscopy. Existing ACS approaches suffer from limitations such as manual input, oversimplifications, or non-physiological methods.

Morphologic analysis of the 1st and 2nd tarsometatarsal joint articular surfaces.

Tarsometatarsal joint arthrodesis is used to treat a variety of injuries and deformities in the midfoot. However, the surgical technique has not been optimized, in part due to limited knowledge of morphologic features and variation in the related joints. Previous research has relied primarily on dissection-based anatomical analysis, but quantitative imaging may allow for a more sophisticated description of this complex.

Joint coverage analysis in progressive collapsing foot deformity.

Progressive collapsing foot deformity (PCFD) is characterized by a progressive subluxation of the peritalar bones and respective joints. Two-dimensional conventional radiographs are limited in their ability to visualize the peritalar bones and joints with adequate detail to describe the complex three-dimensional deformity. An improved understanding of the relationship between joint coverage and deformity would allow clinicians to use coverage analysis to distinguish among the stages of PCFD.

Statistical multi-level shape models for scalable modeling of multi-organ anatomies.

Statistical shape modeling is an indispensable tool in the quantitative analysis of anatomies. Particle-based shape modeling (PSM) is a state-of-the-art approach that enables the learning of population-level shape representation from medical imaging data (e.g.

Biomechanical Insights Afforded by Shape Modeling in the Foot and Ankle.

Advancements in volumetric imaging makes it possible to generate high-resolution three-dimensional reconstructions of bones in throughout the foot and ankle. The use of weightbearing computed tomography allows for the analysis of joint relationships in a consistent natural position that can be used for statistical shape modeling. Using statistical shape modeling, a population-based statistical model is created that can be used to compare mean bone shape morphology and identify anatomical modes of variation.

Acetabular labrum and cartilage contact mechanics during pivoting and walking tasks in individuals with cam femoroacetabular impingement syndrome.

Femoroacetabular impingement syndrome (FAIS) is a motion-related pathology of the hip characterized by pain, morphological abnormalities of the proximal femur, and an elevated risk of joint deterioration and hip osteoarthritis. Activities that require deep flexion are understood to induce impingement in cam FAIS patients, however, less demanding activities such as walking and pivoting may induce pain as well as alterations in kinematics and joint stability. Still, the paucity of quantitative descriptions of cam FAIS has hindered understanding underlying hip joint mechanics during such activities.

Multi-level multi-domain statistical shape model of the subtalar, talonavicular, and calcaneocuboid joints.

Traditionally, two-dimensional conventional radiographs have been the primary tool to measure the complex morphology of the foot and ankle. However, the subtalar, talonavicular, and calcaneocuboid joints are challenging to assess due to their bone morphology and locations within the ankle. Weightbearing computed tomography is a novel high-resolution volumetric imaging mechanism that allows detailed generation of 3D bone reconstructions.

Mechanics and energetics of human feet: a contemporary perspective for understanding mobility impairments in older adults.

Much of our current understanding of age-related declines in mobility has been aided by decades of investigations on the role of muscle-tendon units spanning major lower extremity joints (e.g., hip, knee and ankle) for powering locomotion.

Dual Approach to Talar Dome Increases Access for Fracture Care Without Osteotomy.

Background: There is no consensus surgical treatment algorithm for talar body fractures, with authors recommending both soft tissue-only and osteotomy-based approaches. This study evaluates talar dome access via dual approaches to the talar dome through anterolateral transligamentous (ATL) and modified posteromedial (mPM) approaches.

Methods: Ten cadaveric legs (5 matched pairs) were included.

Medial Head of the Gastrocnemius Tenotomy Through a Posteromedial Approach Significantly Improves Surgical Accessibility of the Tibial Plateau.

Objectives: Compare accessible area of the posterior tibial plateau through a modified posteromedial (PM) approach before and after tenotomy of the medial head gastrocnemius. We report the outcomes of 8 patients who underwent gastrocnemius tenotomy during PM approach.

Methods: A modified PM approach was performed on 10 cadaveric legs, and the surgically accessible area was outlined.

Patients with cam-type femoroacetabular impingement demonstrate increased change in bone-to-bone distance during walking: A dual fluoroscopy study.

Cam-type femoroacetabular impingement (FAI) syndrome is a painful, structural hip disorder. Herein, we investigated hip joint mechanics through in vivo, dynamic measurement of the bone-to-bone distance between the femoral head and acetabulum in patients with cam FAI syndrome and morphologically screened controls. We hypothesized that individuals with cam FAI syndrome would have larger changes in bone-to-bone distance compared to the control group, which we would interpret as altered joint mechanics as signified by greater movement of the femoral head as it articulates within the acetabulum.

Total Ankle Replacement Provides Symmetrical Postoperative Kinematics: A Biplane Fluoroscopy Imaging Study.

Background: In vivo measurements of tibiotalar and subtalar joint motion following TAR are unavailable. Using biplane fluoroscopy, we tested the hypothesis that the prosthetic tibiotalar joint and adjacent subtalar joint would demonstrate kinematic and range of motion differences compared to the contralateral untreated limb, and control participants.

Methods: Six patients of 41 identified candidates that all underwent unilateral Zimmer TAR (5.

Micro-CT analysis of the Lisfranc complex reveals higher bone mineral density in dorsal compared to plantar regions.

Injuries to the Lisfranc complex may require surgical fixation, the stability of which may be correlated with bone mineral density (BMD). However, there is limited research on regional BMD variations in the Lisfranc complex. This study used quantitative micro-CT to characterize regional BMD in the four bones (medial cuneiform, intermediate cuneiform, first metatarsal, and second metatarsal) of this complex.

Talar Dome Access Through Posteromedial Surgical Intervals for Fracture Care.

Background: Posterior talar body fractures are rare injuries without a consensus surgical approach. This study evaluates the accessible area of the talar dome through 2 posteromedial approach intervals (posteromedial [PM] and modified posteromedial [mPM]) both with and without distraction.

Methods: Ten male cadaveric legs (5 matched pairs) were included.

Interaction of loading and ligament injuries in subtalar joint instability quantified by 3D weightbearing computed tomography.

Despite decades of research since its first description, subtalar joint instability remains a diagnostic enigma within the concept of hindfoot instability. This could be attributed to current imaging techniques, which are impeded by two-dimensional measurements. Therefore, we used weightbearing computed tomography imaging to quantify three-dimensional displacement associated with subtalar joint instability.