Survivorship in total knee arthroplasty (TKA) is multifactorial and dependent upon alignment, ligament balance, patient characteristics, and implant factors. The contribution of each factor leading to implant loosening is not well known. This study defined the effect of femoral component sizing relative to tibial size on loading patterns in the proximal tibia. Changes in strain were measured in tibiae implanted with appropriately sized metal-backed tibial components loaded with 2 sizes of femoral components. Significant increases of shear strain up to 126% were measured in peripheral regions of the tibia when loaded with a larger vs a smaller femoral component. Increased peripheral loading in the proximal tibia could predispose to a higher risk of cancellous overload and failure. Limiting stress concentrations in the periphery of the proximal tibia by considering sizing relationships between femoral and tibial components may decrease osseous strains and the likelihood of bony overload in TKA.
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http://dx.doi.org/10.1016/j.arth.2008.11.003 | DOI Listing |
World J Orthop
December 2024
Department for Science, Dubai College, Dubai 00000, Dubayy, United Arab Emirates.
Hip arthroplasty in patients with a history of paediatric hip disorders presents a significant challenge for orthopaedic surgeons. These patients are typically younger and have greater functional demands. Therefore, achieving optimal biomechanical conditions is crucial, involving placement of the acetabulum at the ideal centre of rotation and securing a stable femoral component with good offset to preserve abductor muscle function and restore leg length.
View Article and Find Full Text PDFBone Joint J
January 2025
Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA.
Aims: The purpose of this study was to directly compare the Modular Dual Mobility (MDM) Mobile Bearing Hip System (Stryker, USA) and large femoral heads (LFHs) in revision total hip arthroplasties (THAs) at mid-term follow-up, with specific emphasis on survival free of re-revision for dislocation, any re-revision, dislocation, and the risk of metal-related complications.
Methods: We identified 299 revision THAs performed at a single tertiary care academic institution from March 2011 to July 2014. Aseptic loosening of the acetabular component (n = 65), dislocation (n = 58), and reimplantation as part of a two-stage exchange protocol (n = 57) were the most common reasons for index revision.
Bone Jt Open
January 2025
Department of Orthopaedic Surgery, Ehime University Graduate School of Medicine, Toon, Japan.
Aims: Excellent outcomes have been reported following CT-based robotic arm-assisted total hip arthroplasty (rTHA) compared with manual THA; however, its superiority over CT-based navigation THA (nTHA) remains unclear. This study aimed to determine whether a CT-based robotic arm-assisted system helps surgeons perform accurate cup placement, minimizes leg length, and offsets discrepancies more than a CT-based navigation system.
Methods: We studied 60 hips from 54 patients who underwent rTHA between April 2021 and August 2023, and 45 hips from 44 patients who underwent nTHA between January 2020 and March 2021 with the same target cup orientation at the Department of Orthopedic Surgery at Ozu Memorial Hospital, Japan.
Bone Joint J
January 2025
Musculoskeletal Tumor Section, Department of Orthopedic Surgery, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
Aims: Dislocation is a major concern following total hip arthroplasty (THA) for osteoarthritis (OA). Both dual-mobility components and standard acetabular components with large femoral heads are used to reduce the risk of dislocation. We investigated whether dual-mobility components are superior to standard components in reducing the two-year dislocation and revision risk in a propensity-matched sample from the Danish Hip Arthroplasty Register (DHR).
View Article and Find Full Text PDFBone Joint J
January 2025
Grampian Orthopaedics, Aberdeen Royal Infirmary, Aberdeen, UK.
Aims: The Exeter femoral stem has a cemented, polished taper-slip design, and an excellent track record. The current range includes short-length options for various offsets, but less is known about the performance of these stems. The aim of this study was to compare the survival of short-length stems with standard-length Exeter stems.
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