Three-dimension-printed custom-made prosthetic reconstructions: from revision surgery to oncologic reconstructions

Background The use of custom-made 3D-printed prostheses for reconstruction of severe bone defects in selected cases is increasing. The aims of this study were to evaluate (1) the feasibility of surgical reconstruction with these prostheses in oncologic and non-oncologic settings and (2) the functional results, complications, and outcomes at short-term follow-up. Methods We analyzed 13 prospectively collected patients treated between June 2016 and January 2018. Diagnoses were primary bone tumour (7 patients), metastasis (3 patients), and revision of total hip arthroplasty (3 patients). Pelvis was the most frequent site of reconstruction (7 cases). Functional results were assessed with MSTS score and complications according to Henderson et al. Statistical analysis was performed using Kaplan-Meier and log-rank test curves. Results At a mean follow-up of 13.7 months (range, 6 \u2013 26 months), all patients except one were alive. Oncologic outcomes show seven patients NED (no evidence of disease), one NED after treatment of metastasis, one patient died of disease, and another one was alive with disease. Overall survival was 100% and 80% at one and two years, respectively. Seven complications occurred in five patients (38.5%). Survival to all complications was 62% at two years of follow-up. Functional outcome was good or excellent in all cases with a mean score of 80.3%. Conclusion 3D-printed custom-made prostheses represent a promising reconstructive technique in musculoskeletal oncology and challenging revision surgery. Preliminary results were satisfactory. Further studies are needed to evaluate prosthetic design, fixation methods, and stability of the implants at long-ter

An extendable modular endoprosthetic system for bone tumour management in the leg

A modular endoprosthetic system has been developed at the Groningen University Hospital and the University of Twente. The system can bridge a defect resulting from the resection of a malignant bone tumour which has developed around the knee joint of a child. Since the other healthy leg continues to grow, the system includes an element whose length can be adjusted non-invasively by using an external magnetic field. In addition to this lengthening element, there are one hip and two knee components, connectors of various lengths, and fixation elements. The paper describes the elements of the modular endoprosthetic system. Tables are created by means of which the elemental composition of such an endoprosthesis can be determined for each individual patient

How to salvage a salvage endoprosthesis.

Custom-made endoprostheses can be linked to existing well-fixed implants in the treatment of complex periprosthetic femoral fractures. By adopting this salvage approach, secure implants can be retained in favour of patients undergoing more tissue disruptive procedures such as total femoral replacements. In this piece, we present a unique case illustrating a salvage strategy for treating a failed cement-linked salvage endoprosthesis, a complex scenario which to our knowledge has never before been reported

Custom stems for femoral deformity in patients less than 40 years of age: 70 hips followed for an average of 14 years

Background and purpose Femoral deformity associated with osteoarthritis is a challenge for both the surgeon and the implant. Many of the patients with these deformities are young. Standard implants can be difficult to fit into these femurs. We prospectively evaluated the outcome of custom uncemented femoral stems in young patients

Early Development of Total Hip Replacement

Annotated and edited transcript of a Witness Seminar held on 14 March 2006. Introduction by Dr Francis Neary and Professor John Pickstone. First published by the Wellcome Trust Centre for the History of Medicine at UCL, 2007. ©The Trustee of the Wellcome Trust, London, 2007. All volumes are freely available online at: www.history.qmul.ac.uk/research/modbiomed/wellcome_witnesses/Annotated and edited transcript of a Witness Seminar held on 14 March 2006. Introduction by Dr Francis Neary and Professor John Pickstone,Annotated and edited transcript of a Witness Seminar held on 14 March 2006. Introduction by Dr Francis Neary and Professor John Pickstone,Annotated and edited transcript of a Witness Seminar held on 14 March 2006. Introduction by Dr Francis Neary and Professor John Pickstone,Annotated and edited transcript of a Witness Seminar held on 14 March 2006. Introduction by Dr Francis Neary and Professor John Pickstone,Annotated and edited transcript of a Witness Seminar held on 14 March 2006. Introduction by Dr Francis Neary and Professor John Pickstone,Annotated and edited transcript of a Witness Seminar held on 14 March 2006. Introduction by Dr Francis Neary and Professor John Pickstone,Total hip replacement effectively began in the UK in 1938 and has led to widely used, commercially successful, mass-produced devices that relieve pain for an ever increasing period. The Witness Seminar, chaired by Mr Alan Lettin, discussed the remarkable postwar collaboration of British surgeons, engineers and manufacturing firms in the development of efficient alloys, surgical procedures, instruments and the implementation of clean, bacteria-reduced air in enclosed operating theatres, as illustrated by successful prostheses and techniques developed in Norwich (Kenneth McKee), Wrightington (Sir John Charnley), Stanmore (John Scales), Redhill (Peter Ring), and Exeter (Robin Ling and Clive Lee). Early failures - such as loosening from infection, osteolysis, and wear debris - stimulated the search for improved materials and fixation methods, as well as the addition of antibiotics to bone cement to reduce infection. National hip registers that record the survival of different implants were adopted in Europe in the 1970s (2003 in the UK), and they pinpoint the successful devices, as measured by survival and low rates of revision. An introduction to the volume by Dr Francis Neary and Professor John Pickstone, and appendices on materials by Professor Alan Swanson; on international standards by Mr Victor Wheble; and of details of selected prosthesis supplement the transcript. Contributors include: Lady Charnley, the late Mr Harry Craven, Mr Graham Deane, Professor Duncan Dowson, Mr Reg Elson, Dr Alex Faulkner, Professor Michael Freeman, Mrs Phyllis Hampson, Mr Kevin Hardinge, Mr Mike Heywood-Waddington, Mr John Kirkup, Mr Krishna (Ravi) Kunzru, Miss Betty Lee, Mr Alan Lettin (chair), Mr John Older, Mr John Read, Mr Peter Ring, Mr Ian Stephen, Mr Malcolm Swann, Professor Alan Swanson, Sir Rodney Sweetnam, Mr Keith Tucker, Mr Victor Wheble and Professor Michael Wroblewski. Reynolds L A, Tansey E M. (eds) (2007) Early development of total hip replacement, Wellcome Witnesses to Twentieth Century Medicine, vol. 29. London: The Wellcome Trust Centre for the History of Medicine at UCL.The Wellcome Trust Centre for the History of Medicine at UCL is funded by the Wellcome Trust, which is a registered charity, no. 210183

In vivo evaluation of a vibration analysis technique for the per-operative monitoring of the fixation of hip prostheses

<p>Abstract</p> <p>Background</p> <p>The per-operative assessment of primary stem stability may help to improve the performance of total hip replacement. Vibration analysis methods have been successfully used to assess dental implant stability, to monitor fracture healing and to measure bone mechanical properties. The objective of the present study was to evaluate in vivo a vibration analysis-based endpoint criterion for the insertion of the stem by successive surgeon-controlled hammer blows.</p> <p>Methods</p> <p>A protocol using a vibration analysis technique for the characterisation of the primary bone-prosthesis stability was tested in 83 patients receiving a custom-made, intra-operatively manufactured stem prosthesis. Two groups were studied: one (n = 30) with non cemented and one (n = 53) with partially cemented stem fixation. Frequency response functions of the stem-femur system corresponding to successive insertion stages were compared.</p> <p>Results</p> <p>The correlation coefficient between the last two frequency response function curves was above 0.99 in 86.7% of the non cemented cases. Lower values of the final correlation coefficient and deviations in the frequency response pattern were associated with instability or impending bone fracture. In the cases with a partially cemented stem an important difference in frequency response function between the final stage of non cemented trial insertion and the final cemented stage was found in 84.9% of the cases. Furthermore, the frequency response function varied with the degree of cement curing.</p> <p>Conclusion</p> <p>The frequency response function change provides reliable information regarding the stability evolution of the stem-femur system during the insertion. The protocol described in this paper can be used to accurately detect the insertion end point and to reduce the risk for intra-operative fracture.</p

Biomechanics of Contemporary Implants and Prosthesis: Modeling, Experiments, and Clinical Application

Modern medicine is now more oriented towards patient-based treatments. Taking into account individual biological features allows for increasing the quality of the healing process. Opportunities for modern hardware and software allow not only the complex behavior of implants and prostheses to be simulated, but also take into account any peculiarities of the patient. Moreover, the development of additive manufacturing expands the opportunities for materials. Technical limits for composite materials, biomaterials, and metamaterials are decreasing. On the other hand, there is a need for more detailed analyses of biomechanics research. A deeper understanding of the technological processes of implants, and the mechanobiological interactions of implants and organisms will potentially allow us to raise the level of medical treatment. Modern trends of the biomechanics of contemporary implants and prostheses, including experimental and mathematical modeling and clinical application, are discussed in this book

Design of Custom Made Prosthesis of the Hip

Replacement of a natural hip joint with an artificial is one of the most commonly used surgical procedures in orthopaedic surgery. This paper describes the methodology of the hip joint prosthesis design, which presents the foundation for the automation of all stages of the development of custom-made prostheses. A general mathematical model based mostly on B-spline surfaces is used in order to define the prosthesis geometry. In order to verify the method, a software solution was developed and used for designing prostheses based on ten diagnostic images obtained by various methods. The results of the analysis of the ten designed prostheses, out of which five manufactured, show that deviations from the desired values are less than the errors caused by diagnostic imaging

Total Hip Joint Replacement Biotelemetry System

The development of a biotelemetry system that is hermetically sealed within a total hip replacement implant is reported. The telemetry system transmits six channels of stress data to reconstruct the major forces acting on the neck of the prosthesis and uses an induction power coupling technique to eliminate the need for internal batteries. The activities associated with the telemetry microminiaturization, data recovery console, hardware fabrications, power induction systems, electrical and mechanical testing and hermetic sealing test results are discussed