Mixed Reality-Based Simulator for Training on Imageless Navigation Skills in Total Hip Replacement Procedures

Imageless navigation systems (INS) in orthopaedics have been used to improve the outcomes of several orthopaedic procedures such as total hip replacement [1, 2]. However, the increased surgical times and the associate learning curve discourage surgeons from using navigation systems in their theatres [2]. This paper presents a Mixed Reality (MR) simulator that helps surgeons acquire the infrared based navigation skills before performing it in reality. A group of 7 hip surgeons tried the application, expressing their satisfaction with all the features and confirmed that the simulator represents a cheaper and faster option to train surgeons in the use of INS than the current learning methods

Stem diameter and rotational stability in revision total hip arthroplasty: a biomechanical analysis

BACKGROUND: Proximal femoral bone loss during revision hip arthroplasty often requires bypassing the deficient metaphyseal bone to obtain distal fixation. The purpose of this study was to determine the effect of stem diameter and length of diaphyseal contact in achieving rotational stability in revision total hip arthroplasty. METHODS: Twenty-four cadaveric femoral specimens were implanted with a fully porous-coated stem. Two different diameters were tested and the stems were implanted at multiple contact lengths without proximal bone support. Each specimen underwent torsional testing to failure and rotational micromotion was measured at the implant-bone interface. RESULTS: The larger stem diameter demonstrated a greater torsional stability for a given length of cortical contact (p ≤ 0.05). Decreasing length of diaphyseal contact length was associated with less torsional stability. Torsional resistance was inconsistent at 2 cm of depth. CONCLUSION: Larger stem diameters frequently used in revisions may be associated with less diaphyseal contact length to achieve equivalent rotational stability compared to smaller diameter stems. Furthermore, a minimum of 3 cm or 4 cm of diaphyseal contact with a porous-coated stem should be achieved in proximal femoral bone deficiency and will likely be dependent on the stem diameter utilized at the time of surgery

Revision total hip arthroplasty using the Zweymuller femoral stem

Background: A variety of femoral stem designs have been reported to be successful in revision total hip arthroplasty without consensus as to optimal design. We evaluated the clinical and radiographic outcomes in a consecutive series of femoral revisions using a wedge-shape, tapered-stem design at medium and long-term follow-up. Materials and methods: We performed a retrospective review of clinical and radiographic outcomes of twenty-eight consecutive femoral revisions arthroplasties, which were done using the Zweymuller femoral stem. Results: The mean follow-up was 7.4 years (range 2-15 years). No stem re-revision was necessary. All stems were judged to be stable by radiographic criteria at the most recent follow-up. The final mean Harris hip score was 90. There was no difference in Harris hip scores, implant stability, or radiological appearance (distal cortical hypertrophy or proximal stress shielding) of the implants between medium-term (mean 5.7 years) and long-term (mean 12.4 years) follow-up. Conclusions: We found the Zweymuller femoral stem design to be durable for revision hip arthroplasty when there is an intact metaphyseal-diaphyseal junction for adequate press-fit stability at surgery. © Springer-Verlag 2008

The Dome Technique for Managing Massive Anterosuperior Medial Acetabular Bone Loss in Revision Total Hip Arthroplasty: Short-Term Outcomes

PURPOSE: The dome technique is a technique used in performance of revision total hip arthroplasty (THA) involving intraoperative joining of two porous metal acetabular augments to fill a massive anterosuperior medial acetabular bone defect. While excellent outcomes were achieved using this surgical technique in a series of three cases, short-term results have not been reported. We hypothesized that excellent short-term clinical and patient reported outcomes could be achieved with use of the dome technique. MATERIALS AND METHODS: A multicenter case series was conducted for evaluation of patients who underwent revision THA using the dome technique for management of Paprosky 3B anterosuperior medial acetabular bone loss from 2013-2019 with a minimum clinical follow-up period of two years. Twelve cases in 12 patients were identified. Baseline demographics, intraoperative variables, surgical outcomes, and patient reported outcomes were acquired. RESULTS: The implant survivorship was 91% with component failure requiring re-revision in only one patient at a mean follow-up period of 36.2 months (range, 24-72 months). Three patients (25.0%) experienced complications, including re-revision for component failure, inter-prosthetic dual-mobility dissociation, and periprosthetic joint infection. Of seven patients who completed the HOOS, JR (hip disability and osteoarthritis outcome score, joint replacement) survey, five patients showed improvement. CONCLUSION: Excellent outcomes can be achieved using the dome technique for management of massive anterosuperior medial acetabular defects in revision THA with survivorship of 91% at a mean follow-up period of three years. Conduct of future studies will be required in order to evaluate mid- to long-term outcomes for this technique

Impaction bone grafting of the acetabulum at hip revision using a mix of bone chips and a biphasic porous ceramic bone graft substitute: Good outcome in 43 patients followed for a mean of 2 years

Background and purpose One of the greatest problems of revision hip arthroplasty is dealing with lost bone stock. Good results have been obtained with impaction grafting of allograft bone. However, there have been problems of infection, reproducibility, antigenicity, stability, availability of bone, and cost. Thus, alternatives to allograft have been sought. BoneSave is a biphasic porous ceramic specifically designed for use in impaction grafting. BoneSave is 80% tricalcium phosphate and 20% hydroxyapatite. Previous in vitro and in vivo studies have yielded good results using mixtures of allograft and BoneSave, when compared with allograft alone. This study is the first reported human clinical trial of BoneSave in impaction grafting

Bone and joint infections in adults: a comprehensive classification proposal

Ten currently available classifications were tested for their ability to describe a continuous cohort of 300 adult patients affected by bone and joint infections. Each classification only focused, on the average, on 1.3\u2009\ub1\u20090.4 features of a single clinical condition (osteomyelitis, implant-related infections, or septic arthritis), being able to classify 34.8\u2009\ub1\u200924.7% of the patients, while a comprehensive classification system could describe all the patients considered in the study. RESULT AND CONCLUSION: A comprehensive classification system permits more accurate classification of bone and joint infections in adults than any single classification available and may serve for didactic, scientific, and clinical purposes