Alberto Leardini

• D.Phil.
• Managing Director at Istituto Ortopedico Rizzoli

Aims Patients with knee osteoarthritis (OA) and varus deformity present altered gait parameters, especially a large knee adduction moment that is predictive of OA progression. The distinct role of each coexisting parameter, such as OA grade, varus deformity, and previous meniscectomy, in the setting of high tibial osteotomy is not clear. Therefore,...

Introduction Metal porous structures are becoming a standard design feature of orthopedic implants such as joint endoprostheses. The benefits of the pores are twofold: 1) help improve the cementless primary stabilization of the implant by increasing osteointegration and 2) reduce the overall stiffness of the metal implant thus minimizing stress-shi...

This study investigates the morphological impact of using three-dimensional (3D) printed custom implants in surgical hip reconstruction compared to the conventional bone graft and standard size implant methods. An amount of 16 patients at the Rizzoli Orthopaedic Institute who underwent hip reconstruction surgery for tumors involving the P2 pelvis r...

Early-stage knee osteoarthritis is often suitable for treatment with high tibial osteotomy (HTO). This is an effective joint-preserving treatment, resulting in good postoperative outcomes. To overcome the limitations of traditional HTO, the surgical technique and correction accuracy can be enhanced by personalised procedures using three-dimensional...

Background: This study aimed to evaluate post-operative lower limb function following second-generation mechanically aligned medial pivot (MP) TKA implantation. Standard gait analysis was performed to collect kinematic and kinetic data, which were then compared with physiological data from the literature obtained using the same evaluation methodolo...

Featured Application Inclusion of cone-beam computed-tomography scans in weight-bearing, combined with clinical score systems, may lead to more robust pre- and post-operative evaluations of correction surgery following the modified Grice–Green surgical procedure for adult acquired flatfoot, as well as more biomechanically based skeletal investigati...

Seventy‐eight parameters are theoretically needed to describe the relative position and orientation of all the 14 bones in the foot and ankle with respect to a reference bone (foot posture). However, articular contacts and soft tissues introduce kinematic coupling, reducing the number of the foot degrees‐of‐freedom (DOF). This study aims at providi...

The decade from 2010–2020 has seen the development of cone beam weight-bearing CT (WBCT) as a major innovation in the foot and ankle realm, becoming an important modality for bone and joint imaging. The ability to provide three-dimensional images of the naturally loaded skeleton has enabled several subsequent innovations to arise with aims to haste...

Measuring the forces produced at the ankle joint is critical to diagnose musculoskeletal pathologies. In standard clinical practice, ankle force is often assessed through manual joint manipulation and visual observation. This study introduces a simple apparatus, the Ankle Force Transducer (AFT), based on a uniaxial load cell capable of measuring an...

In March 2021, we invited submissions to the MDPI Special Issue “Biomechanics and Human Motion Analysis”, in the form of original research papers, methodological advances, mini reviews or perspective articles [...]

Featured Application The inclusion of gait analysis, suitably combined with anatomical modelling derived from patient-specific medical imaging, may lead in the near future to more robust post-operative evaluations of personalized HTO to support the efficacy of this surgical technique, as well as innovative and more biomechanically based pre-operati...

The evolution of the medial longitudinal arch (MLA) is one of the most impactful adaptations in the hominin foot that emerged with bipedalism. When and how it evolved in the human lineage is still unresolved. Complicating the issue, clinical definitions of flatfoot in living Homo sapiens have not reached a consensus. Here we digitally investigate t...

Background Custom-made implants are a valid option in revision total hip arthroplasty to address massive acetabular bone loss. The aim of this study was to assess the accuracy of custom-made acetabular implants between preoperative planning and postoperative positioning using CT scans. Methods In a retrospective analysis, three patients who underw...

This scoping review aims to present existing evidence on new technologies reported recently to assess patients with patellofemoral pain (PFP). The literature search was conducted in September 2023, and search engines were Medline (via Pubmed), Scopus, and Cochrane Central. The preferred search term was “patellofemoral pain”, as the 2016 PFP consens...

Background: Patient specific devices represent a promising tool to improve accuracy and simplify high tibial osteotomy (HTO) procedures. The current study aims to assess accuracy of the correction of alignment and posterior tibial slope (PTS), and provide patient reported outcomes (PROMs) of a new personalised cutting guide and fixation plate (TOK...

Introduction: The “postural control system” acts through biomechanical strategies and functional neuromuscular adaptations to maintain body balance under static and dynamic conditions. Postural stability and body weight distribution can be affected by external sensory inputs, such as different visual stimuli. Little information is available about t...

The foot is responsible for the bodyweight transfer to the ground, while adapting to different terrains and activities. Despite this fundamental role, the knowledge about the foot bone intrinsic kinematics is still limited. The aim of the study is to provide a quantitative and systematic description of the kinematics of all bones in the foot, consi...

High Tibial Osteotomy is frequently performed to correct varus knees misalignment and thus to prevent end-stage osteoarthritis. Traditional systems lack pre-surgical planning and custom-fit fixation plates. A new 3D printed system has been developed for a personalized surgical procedure. This starts with careful correction planning based on a stand...

High tibial osteotomy (HTO) is a joint preserving alternative to knee replacement for medial tibiofemoral osteoarthritis in younger, more active patients. The procedure is technically challenging and limited also by ‘one size fits all’ plates which can result in patient discomfort necessitating plate removal. This clinical trial evaluated A novel c...

This study explores knowledge sharing in temporary teams which use 3D printing technology to support surgical interventions. We focus on the planning phase of orthopaedic surgeries when senior surgeons organise a temporary team to create personalised treatment using 3D printing technology. We conduct in-depth interviews with 25 surgeons and their t...

The present review paper aimed at discussing the current major issues in total ankle replacement, both the technical and biomechanical concepts, and the surgical and clinical concerns. Designers shall target at the same time restoration of natural ankle kinematics and congruity of the artificial surfaces throughout the range of motion. Surgeons are...

Background: Adult acquired flat foot (AAFF) is a symptomatic postural alteration of the foot due to modifications in bony structures and/or soft tissues supporting the medial longitudinal arch. For the most severe cases, when orthotic solutions do not provide enough pain relief, surgery may be necessary. Research question: Is it possible to rest...

Three-dimensional (3D)-printed anatomical models of the bones play a key role in complex surgical procedures. These subject-specific physical models are valuable in pre-operative planning and may also offer assistance during surgery by improving the visibility of inaccessible anatomical structures, particularly in spine surgery. Starting from medic...

Despite showing promising functional outcomes for pelvic reconstruction after sarcoma resection, custom-made pelvic implants continue to exhibit high complication rates due to fixation failures. Patient-specific finite element models have been utilized by researchers to evaluate implant durability. However, the effect of assumed boundary and loadin...

Cone-beam CT (CBCT) scans now enable accurate measurements on foot skeletal structures with the advantage of observing these in 3D and in weight-bearing. Among the most common skeletal deformities, the varus/valgus of the hindfoot is the most complex to be represented, and a number of measure proposals have been published. This study aims to analyz...

Background: The accuracy of the coronal alignment corrections using conventional high tibial osteotomy (HTO) falls short, and multiplanar deformities of the tibia require consideration of both the coronal and sagittal planes. Patient-specific instrumentations have been introduced to improve the control of the correction. Clear evidence about custo...

Ankle-Foot Orthoses (AFOs) are the most common devices prescribed to support the ankle and restore a quasi-normal gait pattern in drop-foot patients. AFO stiffness is possibly the main mechanical property affecting foot and ankle biomechanics. A variety of methods to evaluate this property have been reported, however no standard procedure has been...

Background Anatomical custom-made prostheses make it possible to reconstruct complicated bone defects following excision of bone tumors, thanks to 3D-printed technology. To date, clinical measures have been used to report clinical-functional outcome and provide evidence for the effectiveness of this new surgical approach. However, there are no stud...

Objective: Osteoarthritis (OA) is a multifactorial musculoskeletal disorder affecting mostly weight-bearing joints. Chondrocyte response to load is modulated by inflammatory mediators and factors involved in extracellular cartilage matrix (ECM) maintenance, but regulatory mechanisms are not fully clarified yet. By using a recently proposed experime...

Three-dimensional bone shape reconstruction is a fundamental step for any subject-specific musculo-skeletal model. Typically, medical images are processed to reconstruct bone surfaces via slice-by-slice contour identification. Freeware software packages are available, but commercial ones must be used for the necessary certification in clinics. The...

Background. Mechanical models of the human ankle complex are used to study the stabilizing role of ligaments. Identification of ligament function may be improved via image-based personalized approach. The aim of this study is to compare the effect of the ligament origin and insertion site definitions obtained with different magnetic resonance imagi...

Ankle foot orthoses (AFOs) are medical devices prescribed to support the foot and ankle of drop-foot patients. Passive-dynamic AFOs (PD-AFOs) are an effective solution for less severe cases. While off-the-shelf PD-AFOs are rather inexpensive, they provide poor anatomical fit and do not account for the required patient-specific biomechanical support...

In orthopaedic oncology, limb salvage procedures are becoming more frequent thanks to recent major improvements in medical imaging, biomechanical modelling and additive manufacturing. For the pelvis, surgical reconstruction with metal implants after tumor resection remains challenging, because of the complex anatomical structures involved. The aim...

Background A fully personalized combination of Gait Analysis (GA), including Ground Reaction Force (GRF), and patient-specific knee joint morphology has not yet been reported. This can provide valuable biomechanical insight in normal and pathological conditions. Abnormal knee varus results in medial knee condylar hyper-compression and osteoarthriti...

Background A complete definition of anatomical reference systems (ARS) for all bones of the foot and ankle complex is lacking. Using a morphological approach, we propose new ARS for these bones with the aim of being highly repeatable, consistent among individuals, clinically interpretable, and also suited for a sound kinematic description. Methods...

Diabetic foot syndrome refers to heterogeneous clinical and biomechanical profiles, which render predictive models unsatisfactory. A valuable contribution may derive from identification and descriptive analysis of well-defined subgroups of patients. Clinics, biology, function, gait analysis, and plantar pressure variables were assessed in 78 patien...

Static and dynamic measurements of the medial longitudinal arch (MLA) in the foot are critical across different clinical and biomechanical research fields. While MLA deformation can be estimated using skin-markers for gait analysis, the current understanding of the correlates between skin-marker based models and radiographic measures of the MLA is...

While lower limb biomechanics of people with diabetes are well described, the effects of diabetes type and of peripheral neuropathy on foot joint kinematics have not been addressed in depth. A total of 70 patients with type 1 (n = 25) and type 2 (n = 45) diabetes mellitus, with and without peripheral neuropathy, underwent functional evaluation via...

Background: The clinical outcomes of total ankle replacement are limited by prosthesis component malpositioning during surgery. The goal of this study is to assess the mechanical impact of this malpositioning in a validated computer model. Methods: In a previously developed multi-body dynamic model of the human ankle complex three different arti...

Acquired adult flatfoot is a frequent deformity which implies multiple, complex and combined 3D modifications of the foot skeletal structure. The difficult thorough evaluation of the degree of severity pre-op and the corresponding assessment post-op can now be overcome by cone-beam (CBCT) technology, which can provide access to the 3D skeletal stru...

This study proposes a new method for the definition of anatomical reference system (ARS) for the bones of foot and ankle based on morphological and functional criteria, meant for the 3D description of the foot posture. The method shows high inter-and intra-operator precision (<1° and <1mm), providing a 3D characterization of the foot arches, which...

The aim of this work is to propose and validate a semi-automatic procedure, including bone segmentation and ICP-based bone registration, for the reconstruction of bone kinematics in the foot and ankle through Weight-Bearing CT. The semi-automatic segmentation is compared to manual one and the overall accuracy of the procedure is addressed.

We investigated the motion of the foot and ankle bones from a series of static Weight Bearing CT (WBCT) scans, evaluating load related variation through principal component analysis (PCA). For the two investigated feet, unloaded motion can be explained with three synergies. When load is considered, a fourth synergy is needed. In both cases, all the...

The foot is anatomically and functionally complex, and thus an accurate description of intrinsic kinematics for clinical or sports applications requires multiple segments. This has led to the development of many multi-segment foot models for both kinematic and kinetic analyses. These models differ in the number of segments analyzed, bony landmarks...

Human bones are biological examples of functionally graded lattice capable to withstand large in vivo loading and allowing optimal stress distribution. Disruption of bone integrity may require biocompatible implants capable to restore the original bone structure and properties. This study aimed at comparing mechanical properties and biological beha...

It is established that human movements in the vicinity of a permanent static magnetic field, such as those in magnetic resonance imaging (MRI) scanners induce electric fields in the human body; this raises potential severe risks of health to radiographers and cleaners exposed routinely to these fields in MRI rooms. The relevant directives and param...

Osteoarthritis (OA) is an evolving disease and a major cause of pain and impaired mobility. A deeper understanding of cartilage metabolism in response to loading is critical to achieve greater insight into OA mechanisms. While physiological joint loading helps maintain cartilage integrity, reduced or excessive loading have catabolic effects. The ma...

Purpose To compare weight-bearing cone-beam computer tomography (CBCT) and conventional computer tomography (CT)-based measurements of patellofemoral alignment and stability in patients surgically treated for recurrent patellar dislocation. These scans implied respectively single-leg up-right posture, the knee flexed, and lower limb muscles activat...

Background Foot healthcare research is focusing increasingly on personalized orthotic and prosthetic devices to address patient-specific morphology and ailments. Customization requires advanced 3D image processing tools to assess foot and leg geometrical parameters and alterations. The aim of this study is to present a new software for the measurem...

Hip dysplasia patients after total hip replacement show worse functional performance compared to primary osteoarthritis patients, and unfortunately there is no research on muscle and joint loads that would help understand rehabilitation effects, motor dysfunctions and failure events. We tested the hypothesis that a higher functional improvement in...

This study aims to develop techniques for ankle joint kinematics analysis using motion capture based on stereophotogrammetry. The scope is to design marker attachments on the skin for a most reliable identification of the instantaneous helical axis, to be targeted for the fabrication of customized hinged ankle-foot orthoses. These attachments shoul...

Background: Computer navigation and patient-specific instrumentation for total ankle arthroplasty have still to demonstrate their theoretical ability to improve implant positioning and functional outcomes. The purpose of this paper is to present a new and complete total ankle arthroplasty customization process for severe posttraumatic ankle joint...

Background Total ankle arthroplasty is intended to restore physiological joint function in case of severe ankle arthritis. However, little is known about the functional outcome associated to different prosthesis designs. The aim of this retrospective study was to compare clinical and functional outcomes via gait analysis of two ankle prostheses des...

Different location and incidence of lower extremity injuries have been reported in rearfoot strike (RFS) and forefoot strike (FFS) recreational runners. These might be related to functional differences between the two footstrike patterns affecting foot kinematics and thus the incidence of running injuries. The aim of this study was to investigate a...

Background Measurements of plantar loading reveal foot-to-floor interaction during activity, but information on bone architecture cannot be derived. Recently, cone-beam computer tomography (CBCT) has given visual access to skeletal structures in weight-bearing. The combination of the two measures has the potential to improve clinical understanding...

Skin-markers based multi-segment models are growing in popularity to assess foot joint kinematics in different motor tasks. However, scarce is the current knowledge of the effect of high-energy motor tasks, such as running, on the repeatability of these measurements. This study aimed at assessing and comparing the inter-trial, inter-session, and in...

Background The Oxford Foot Model (OFM) and Rizzoli Foot Model (RFM) are the two most frequently used multi-segment models to measure foot kinematics. However, a comprehensive comparison of the kinematic output of these models is lacking. Research question What are the differences in kinematic output between OFM and RFM during normal gait and typic...

With the goal to restore ankle and foot function also in the long term, custom-made prostheses are becoming more frequently possible solutions for severe bone loss and avascular necrosis of the talus. A young professional rock climber was implanted with a custom-made talonavicular prosthesis, and short-term (30 months) assessment has been published...

Background: Emerging sensing and communication technologies are contributing to the development of many motor rehabilitation programs outside the standard healthcare facilities. Nowadays, motor rehabilitation exercises can be easily performed and monitored even at home by a variety of motion-tracking systems. These are cheap, reliable, easy-to-use...

After a total hip arthroplasty, a limited range of motion and lower-limb disability continue to be observed, with these being mainly associated with the implant design and the head-to-neck ratio. Larger diameters of the head bearings were assumed to provide better stability, a larger range of motion, and smaller risks of dislocation and stem-to-lin...

Background In severe cases of ankle and subtalar arthritis, arthrodesis of the subtalar joint is performed in combination with ankle arthroplasty. In these special cases gait analysis reveals real motion at the replaced tibiotalar joint. Methods 23 patients affected by ankle and subtalar arthritis, treated either with a 3-component or a 2-componen...

Background For the diagnosis and treatment of foot and ankle disorders, objective quantification of the absolute and relative orientation angles is necessary. The present work aims at assessing novel techniques for 3D measures of foot bone angles from current Cone-Beam technology. Methods A normal foot was scanned via weight-bearing CT and 3D-mode...

The foot seems to demonstrate considerable power absorption and generation characteristics during running. These have been mainly accounted to the mechanics of the ankle joint, however, evidence suggests that joint kinetics have been overestimated by single-segment foot models. The scope of the present study was to estimate the energetics of the an...

Biomechanical models of the knee joint allow the development of accurate procedures as well as novel devices to restore the joint natural motion. They are also used within musculoskeletal models to perform clinical gait analysis on patients. Among relevant knee models in the literature, the anatomy-based spatial parallel mechanisms represent the jo...

Objective Soldiers’ lower limbs and feet are frequently affected by overload- and overuse-related injuries. In order to prevent or limit the incidence of these injuries, the use of foot orthoses is often recommended. The aim of this study is to assess the effects of shock-absorbing insoles on in-shoe plantar pressure magnitude and distribution in a...

The aim of this study was to analyze the extent to which postoperative patellofemoral joint (PFJ) kinematics assessed at 6-month follow-up after total knee arthroplasty (TKA) mimics the intraoperative kinematics after final component implantation. The study hypothesis, already proved in terms of tibiofemoral joint (TFJ) kinematics, is that the intr...

The case of a former high-level professional soccer player is presented at 10-year follow-up after arthroscopically implanted lateral Collagen Meniscus Implant (CMI). The patient achieved a full-knee functional recovery and a complete sport resumption to the same pre-injury level for several soccer seasons and he is still performing semi-profession...

Background: Advancements in additive manufacturing, along with new 3D scanning tools, are increasingly fulfilling the technological need for custom devices in personalized medicine. In podiatry and in the footwear industry, custom orthotic and footwear solutions are often required to address foot pathologies or morphological alterations which cann...

Musculoskeletal radiology has been mostly limited by the option between imaging under load but in two dimensions (i.e., radiographs) and three-dimensional (3D) scans but in unloaded conditions (i.e., computed tomography [CT] and magnetic resonance imaging in a supine position). Cone-beam technology is now also a way to image the extremities with 3D...

The International Society of Biomechanics (ISB) has charged this committee with development of a standard similar in scope to the kinematic standard proposed in Wu et al. (2002) and Wu et al. (2005). Given the variety of purposes for which intersegmental forces and moments are used in biomechanical research, it is not possible to recommend a partic...

Foot structure and kinematics have long been considered as risk factors for foot and lower-limb running injuries. The authors aimed at investigating foot joint kinetics to unravel their receptive and propulsive characteristics while running barefoot, both with rearfoot and with midfoot striking strategies. Power absorption and generation occurring...

Knowledge of the stabilizing role of the ankle and subtalar ligaments is important for improving clinical techniques such as ligament repair and reconstruction. However, this knowledge is incomplete. The goal of this study was to expand this knowledge by investigating the stabilizing function of the ligaments using multiple morphologically subject-...

Category Hindfoot Introduction/Purpose An adult-acquired flatfoot deformity is a three-dimensional (3D) condition characterized by a loss of the medial longitudinal arch, valgus alignment of the hindfoot, and abduction of the midfoot. When conservative measures are not sufficient, a medializing calcaneal osteotomy (MCO) is frequently performed to...