Ankle prosthesis

BACKGROUND: The purpose of this study was to evaluate the clinical and radiological outcomes of high-flexion total knee arthroplasty (TKA) using Vega Knee System (B. Braun, Aesculap) at a long-term follow-up and to analyze the implant survivorship. METHODS: We enrolled 165 patients (232 knees) with a minimum 7-year follow-up after TKA (VEGA Knee System). For clinical assessment, range of motion (ROM), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) were used...

OBJECTIVES: Residual varus after total knee arthroplasty (TKA) can affect functional outcomes, which may worsen in the presence of obesity. However, no studies were found to compare the outcomes of obese patients involving postoperative residual mild varus or neutral. The aim of this study was to compare postoperative complications and prosthesis survival, and functional outcomes for knees of obese patients with neutral or mild varus after TKA. METHODS: We retrospectively reviewed 188 consecutive obese patients (body mass index ≥30 kg/m2 ) at our hospital who underwent TKA due to varus knee osteoarthritis from January 2010 to December 2015...

The spacer block technique is widely used in medial fixed-bearing unicompartmental knee arthroplasty (UKA) for osteoarthritis (OA) and osteonecrosis (ON), while it is still unclear if there is any difference in the extension gap between UKAs for the two conditions. To clarify the question, the data from 87 consecutive patients (OA: 57 patients and ON: 30 patients) who underwent medial fixed-bearing UKA with the spacer block technique were retrospectively collected and analyzed. The component gap between the medial tibial osteotomy surface and the femoral trial prosthesis in extension was measured using a UKA tensor, and the preosteotomy gap was calculated in each condition...

Ambulation in everyday life requires walking at variable speeds, variable inclines, and variable terrains. Powered prostheses aim to provide this adaptability through control of the actuated joints. Some powered prosthesis controllers can adapt to discrete changes in speed and incline but require manual tuning to determine the control parameters, leading to poor clinical viability. Other data-driven controllers can continuously adapt to changes in speed and incline but do so by imposing the same non-amputee gait patterns for all amputee subjects, which does not consider subjective preferences and differing clinical needs of users...

BACKGROUND: Reconstruction with vascularized fibula grafts (VFG) after intercalary resection of sarcoma may offer longevity by providing early graft-host union and fracture healing. The ability of the fibula to hypertrophy under mechanical stress, as well as vascularized bone in the area, may also be advantageous, given that soft tissues may be compromised because of resection, chemotherapy, or radiation therapy. VFG with a massive allograft combines the primary mechanical stability of the graft with the biological potential of the vascularized fibula; however, complications and the durability of this combined reconstruction are not well described...

BACKGROUND: Lower limb amputation contributes to structural and functional brain alterations, adversely affecting gait, balance, and overall quality of life. Therefore, selecting an appropriate prosthetic ankle is critical in enhancing the well-being of these individuals. Despite the availability of various prostheses, their impact on brain neuroplasticity remains poorly understood. OBJECTIVES: The primary objective is to examine differences in the degree of brain neuroplasticity using magnetic resonance imaging (MRI) between individuals wearing a new passive ankle prosthesis with an articulated ankle joint and a standard passive prosthesis, and to examine changes in brain neuroplasticity within these two prosthetic groups...

Reducing energy consumption during walking is a critical goal for transtibial amputees. The study presents the evaluation of a semi-active prosthesis with five transtibial amputees. The prosthesis has a low-power actuator integrated in parallel into an energy-storing-and-releasing foot. The actuator is controlled to compress the foot during the stance phase, supplementing the natural compression due to the user's dynamic interaction with the ground, particularly during the ankle dorsiflexion phase, and to release the energy stored in the foot during the push-off phase, to enhance propulsion...

BACKGROUND: Joint salvage surgeries such as tibiotalocalcaneal arthrodesis and talar prosthesis are commonly used in the surgical treatment of collapsed avascular necrosis of the talus (AVNT). However, differences in outcomes of these 2 surgical treatments are still inconclusive. This study compared the 10- to 13-year outcomes and 10-year survivorship rates of tibiotalocalcaneal arthrodesis and talar body prosthesis in the surgical treatment of collapsed AVNT. METHODS: A retrospective comparative study was conducted of patients who underwent either tibiotalocalcaneal arthrodesis or talar body prosthesis implantation between 2005 and 2012...

Individuals with transtibial amputation (TTA) experience asymmetric lower-limb loading which can lead to joint pain and injuries. However, it is unclear how walking over unexpected uneven terrain affects their loading patterns. This study sought to use modeling and simulation to determine how peak joint contact forces and impulses change for individuals with unilateral TTA during an uneven step and subsequent recovery step and how those patterns compare to able-bodied individuals. We expected residual limb loading during the uneven step and intact limb loading during the recovery step would increase relative to flush walking...

BACKGROUND: The incidence of all periprosthetic fractures (PPF), which require complex surgical treatment associated with high morbidity and mortality, is predicted to increase. The evolving surgical management has created a knowledge gap regarding its impact on immediate outcomes. This study aimed to describe current management strategies for PPF and their repercussions for in-hospital outcomes as well as to evaluate their implications for the community. METHODS: PIPPAS (Peri-Implant PeriProsthetic Survival Analysis) was a prospective multicentre observational study of 1387 PPF performed during 2021...

PURPOSE: The results of medial open-wedge high tibial osteotomy (MOWHTO) according to age is inconclusive. This study aimed to compare the clinical outcomes and failure of MOWHTO in patients < 55 years and > 65 years. METHODS: Consecutive patients who underwent MOWHTO from July 2009 to August 2020 were retrospectively analyzed. 205 patients were considered for analysis. A 1-to-1 propensity score matched analysis to assess clinical outcomes scores including International Knee Documentation Committee (IKDC) subjective score and Lysholm score, radiologic outcomes, complication, and Total Knee Arthroplasty (TKA) conversion between patients > 65 years and patients < 55 years was performed...

OBJECTIVE: We investigated the advantages of robotic arm-assisted total knee arthroplasty (raTKA) over conventional manual TKA (cmTKA) by comprehensively comparing patients who received raTKA and cmTKA in terms of postoperative pain, function, imaging assessment, and trauma to the body. This study investigated the efficacy and safety of raTKA in patients using the YUANHUA-TKA system. METHODS: In a prospective, randomized single-blind trial, 60 patients undergoing primary unilateral TKA from October 2020 to December 2020 were randomly assigned to either raTKA or cmTKA...

Conjoined twins are identical twins joined in utero and are a rare phenomenon. This report discusses a case of female thoraco-omphalo-ischiopagus tripus conjoined twins. The twins were separated at age two, and once medically stable, spent one month in inpatient rehabilitation to improve their sitting balance and gross motor skills. This was followed by outpatient physical therapy. The twins initially had customized ZipZac seats, which they were able to wheel independently. After six months of therapy, the girls began walking with posterior walkers and prostheses...

Powered ankle prostheses have been proven to improve the walking economy of people with transtibial amputation. All commercial powered ankle prostheses that are currently available can only perform one-degree-of-freedom motion in a limited range. However, studies have shown that the frontal plane motion during ambulation is associated with balancing. In addition, as more advanced neural interfaces have become available for people with amputation, it is possible to fully recover ankle function by combining neural signals and a robotic ankle...

INTRODUCTION: Amputation leads to a permanent disability and brings a dramatic change in the life and function of the individual, more so in individuals with lower limb amputation. A lower limb amputation reduces mobility and can make persons dependent on assistive devices like crutches or a wheelchair. Restoring mobility and optimal physical functioning of an individual with lower limb amputation is the most important rehabilitation goal. There are very few studies that have quantified mobility deficits with valid outcome measures, especially in the Indian population...

INTRODUCTION: Powered prosthetic feet require customized tuning to ensure comfort and long-term success for the user, but tuning in both clinical and research settings is subjective, time intensive, and the standard for tuning can vary depending on the patient's and the prosthetist's experience levels. METHODS: Therefore, we studied eight different metrics of gait quality associated with use of a research-grade powered prosthetic foot in seven individuals with transtibial amputation during treadmill walking...

This short communication presents the gait1415+2 musculoskeletal model, that has been developed in OpenSim to describe the lower-extremity of a human subject with transfemoral amputation wearing a generic lower-limb bone-anchored prosthesis. The model has fourteen degrees of freedom, governed by fifteen musculotendon units (placed at the contralateral and residual limbs) and two generic actuators (one placed at the knee joint and one at the ankle joint of the prosthetic leg). Even though the model is a simplified abstraction, it is capable of generating a human-like walking gait and, specifically, it is capable of reproducing both the kinematics and the dynamics of a person with transfemoral amputation wearing a bone-anchored prosthesis during normal level-ground walking...

This study examines the correlation between the weight-bearing (WB) long leg radiograph (LLR) derived hip-knee-ankle angle (HKAA) and intra-operative supine computer-assisted surgery (CAS) derived HKAA measurements at the beginning and end of total knee arthroplasty (TKA). The primary aim of the study was to determine if weight-bearing alignment could be mimicked or inferred based on intra-operative alignment findings. We conducted a prospective analysis from a cohort of 129 TKAs undergoing a CAS TKA at a single centre by a single surgeon...

Patients with bilateral ankle arthritis have higher rates of primary and secondary/inflammatory arthritis and a more debilitating condition than those with unilateral pathology. The limited bilateral total ankle arthroplasty (TAA) literature supports both 1-surgeon and 2-surgeon team bilateral TAAs as safe and effective with comparable improvements in patient-reported outcome measures (PROMs), complications, reoperations, and prosthesis survival as unilateral TAA and staged bilateral TAA. Additional benefits of bilateral arthroplasty supported in the hip and knee literature include cost reduction, noninferior and even superior perioperative complication profiles, improved PROM and satisfaction, shorter recovery time, early rehabilitation, and less time away from employment...

Powered knee-ankle prostheses can offer benefits over conventional passive devices during stair locomotion by providing biomimetic net-positive work and active control of joint angles. However, many modern control approaches for stair ascent and descent are often limited by time-consuming hand-tuning of user/task-specific parameters, predefined trajectories that remove user volition, or heuristic approaches that cannot be applied to both stair ascent and descent. This work presents a phase-based hybrid kinematic and impedance controller (HKIC) that allows for semi-volitional, biomimetic stair ascent and descent at a variety of step heights...