Background: Infection remains the single most devastating complication of joint arthroplasty. In cases of established prosthetic infection, where implant retention is not feasible, there is limited consensus on an optimum management protocol.

Aim: To assess the outcome of revision for infected hip prostheses using a novel treatment regimen.

Materials and Methods: Retrospective study of a consecutive case series of 40 patients with late chronic hip joint prosthetic infection treated by a single surgeon over a 4 year period. The mean interval between index arthroplasty and revision for infection was 40 months, with patients having prior symptoms of infection for a mean of 22 months.

The treatment protocol consisted of a two stage exchange with removal of infected components via a posterior approach incorporating an extended trochanteric osteotomy, insertion of an interim antibiotic eluting cement spacer and re-implantation of an extensively coated uncemented prosthesis on the femoral side. Systemic antibiotic treatment following each stage consisted of an abridged course of 5 days post operative intravenous administration followed by complete cessation of anti-microbial therapy. The mean interval between implant removal and re-implantation was 111 days.

Results: At a mean follow up of 29.6 months (minimum 12 months), there were 2 cases of recurrent prosthetic infection. Dislocation following the second stage occurred in 7 patients. There was one mortality and one case of post operative sciatic nerve palsy. The Harris hip score increased from a pre-operative mean of 43.8 to a post operative mean of 83.9. At follow up, no patient had required revision for aseptic loosening or mechanical instability on the femoral side

Conclusion: The combination of effective staged surgical joint debridement, a shortened post operative course of systemic antibiotic treatment and an adequate latent period before re-implantation has led to encouraging early results in this series of revised chronic hip joint prosthetic infections.

Objectives

A possible solution for the management of proximal femoral bone loss is a modular femoral endoprosthesis (EPR). Although the outcome of EPRs in tumour surgery has been well described, the outcome of their use in revision hip surgery has received less attention. The aim of this study was to describe the outcome of using EPR for non-neoplastic indications.

Abstract. Introduction. In general the life expectancy of population is improving. This is causing to increase case load of peri-prosthesis fractures after joint replacements. We present our results of peri-prosthesis fracture around hip managed by revision arthroplasty. Methods. A retrospective analysis of 24 consecutive patients of periprosthetic hip fracture treated with a revision arthroplasty at Major Trauma Centre between February 2021 and January 2022. Results. 12 male and 12 female patients, average age 78 years. 3 fractures around BHR prosthesis, 2 type A, 15 type B and 3 of type C (Vancouver). The surgery was done in an average 6 days after injury (range 1–14). 6 patients died in follow up, 1 patient contracted infection, 2 developed LLD and 1 patient had multiple dislocations. 6 patients had revision using endo-prosthesis. Advanced age with peri-prosthesis fracture has increased risk of mortality (average age 84.5 years). Conclusion. Endo-prosthesis replacement had higher risk of dislocation, infection and mortality. Overall patients do well after a revision arthroplasty for periprosthetic hip fracture. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

The thrust plate prosthesis (TPP) is a femoral implant which stimulates physiological loading. This eliminates stress shielding, hence subsequent aseptic loosening of the femoral endo-prosthesis (Huggler/Jacob et al). Between December 1994 and December 1999, TPP (third generation prototype) were inserted in 63 hips in 58 patients between the ages of 19 and 75. This is a study and follow-up of one single surgeon. 46 hips in 41 patients were available for follow-up, clinical assessment (Harris Hip Score) and radiological evaluation (Buergi et al). The average hip score improved from a pre-operative score of 39 to 94 postoperatively. All patients achieved their occupational status post-operatively. Radiological evaluation assesses the cortical bone reaction in the mediocaudad zone of the femoral neck to the thrust plate. 36 hips (80%) maintained excellent osseous ingrowth between the mediocaudad femoral neck and the flat surface of the thrust plate (Type I reaction). There were 3 loosenings (technical error/poor selections), 1 deep infection, 2 stress fractures, 9 (20%) myositis ossificans, 1 broken screw and no dislocations. Implantation requires:. pre-operative templating,. careful precision with the preferred 130° of neck femoral shaft angle. firm osseous fixation. Revision surgery, if required, is uncomplicated. It will be as for implanting a primary endo-prosthesis due to the preservation of excellent bone stock. The study shows promise of longevity and one hip arthroplasty for life, especially in young patients

Background: Chronic prosthetic joint infection is a cause of patient morbidity and can be challenging to treat. Surgeons performing revision arthroplasty of the hip and knee are confronted with a growing number of patients with extensive loss of bone stock. The use of a modular endoprosthesis is a possible method of treatment in such patients. Aim: The purpose of this study was to assess the functional outcomes and the success of a single and two stage revision procedure in eradicating chronic prosthetic joint infection using a femoral endoprosthesis. Methods: A prospective database was reviewed of 20 patients who underwent a proximal, total or distal femoral endoprosthetic replacement after chronic prosthetic infection. Radiographs performed at the time of latest follow up were evaluated for signs of loosening, osteomyelitis and implant failure. The functional status was assessed using the Short Form (SF)-36 health survey score, Toronto extremity salvage score (TESS) and the Enneking score. Results: Thirteen patients underwent a single stage revision procedure and seven had been treated with a staged revision. At the latest follow up none of the 13 patients treated with a single stage procedure had evidence of ongoing infection. Of the seven patients who had a staged revision, 3 patients had evidence of ongoing infection. The mean pre operative Enneking score for the entire group was 17.1 points and this improved to 47.5 points post operatively (p< 0.0002). The mean pre operative TESS score for the entire group was 42% and this improved to 59% post operatively (p< 0.005). There was also a statistically significant improvement in all of the components of the SF-36 score. Conclusion: We believe that the use of a modular endo-prosthesis in the treatment of chronic prosthetic joint infection is a successful and viable option in eradicating infection, preserving the limb and providing a good functional result

Massive cemented endoprosthesis are used to enable early resumption of activity after tumour surgery. The longevity of the prosthesis varies with anatomical site, pros-thesis type, and mode of þxation. Revision surgery will be required in approximately 50% of cases of endopros-thetic replacements around the knee by 10 years because of aseptic loosening. Insertion of a second cemented endoprosthesis is a challenge because of the poor quality of the remaining bone and loosening recurs quickly. The use of extracortical plate þxation in joint sparing surgery where the remaining bone after tumour resection will not accept an intramedullary stem is also described. The þrst series of 14 patients with extracortical plate þxation in difþcult revision or joint-sparing tumour surgery with a mean follow-up of 5 years are described. The three-plate design incorporates well within a remodelled cortex to achieve osseomechanical integration with all patients regaining their premorbid level of function within 5 months. At 5 years the Enneking scores averaged 27.3. One revision was required in a femoral replacement because of loosening. It was possible to insert a new endo-prosthesis as the intramedullary bone had reconstituted. The preliminary results suggest that this technique may provide an easy, biomechanically friendly alternative to a device with an intramedullary stem, which has a shorter lifespan in revision tumour surgery

The first Ceramic knee implant in a human patient was used by Dr. G. Langer of the Orthopedic Clinic at the University of Jena, Germany in 1972 [. 1. ]. In 1980, Drs. Oonishi and Hasegave began using a Alumina femoral component on a polyethylene tibial component [. 2. ]. These early attempts all involve the search for solutions to the wear and degradation problems. The application of ceramics was limited by the demand of thin components. In the present feasibility study the in vitro wear behavior of a knee concept with a novel Alumina Matrix Composite (AMC) Ceramic was examined [. 3. ,. 4. ]. The wear behavior of the Ceramic components for the knee system were tested in accordance to ISO/WD 14243-3 for 5*106 cycles. Six samples were tested. The lubricant was calf serum diluted with deionized water. All tests have been performed with components made of the novel AMC Ceramic. The wear test performed showed an average gravimetric wear rate below 1 mg/1*106 cycles on each of the six components. A change of geometry was not measurable after 5 million cycles. No significant change of the surface structure was detectable with a conventional surface tracer. SEM and AFM pictures show traces of ultra mild abrasive wear at the surface. The performed investigation on the novel knee concept shows the following potential benefits for a Ceramic knee bearing:. approx. 500 times lower volumetric wear. low risk of tribologically induced failure. no PE particle induced osteolysis. The novel AMC Ceramic offers a solution to minimize the allergic and wear related problems of knee implants. New concepts on the basis of hard on hard combination are to be realized. The use of knee endo-prosthesis with Ceramic on Ceramic combination is an option for îzeroî wear bearings in the knee. These first results motivate to start further R& D on Ceramic on Ceramic bearings for total knee implants

Summary Statement. A porcine model using Yucatan minipigs was found to be very promising for the investigation of healing around transcutaneous osseointegrated implants. Pigs demonstrated surprising agility and adaptability including the ability to ambulate on three legs during the immediate postoperative period. Introduction. Previous non weight-bearing and weight-bearing caprine, canine and ovine models have evaluated design, material, and biological coating variations in an attempt to improve the wound healing and skin-implant seal around transcutaneous osseointegrated implants. Although these models have primarily been used as a window into the application of transcutaneous osseointegrated implants in humans, some important model characteristics affecting wound healing and infection have been missing including: 1) replication of the physiological tissue response, and 2) availability of a transcutaneous site with sufficient soft tissue coverage. Pig skin, like human, is relatively hairless, tightly attached to the subcutaneous tissue, vascularised by a cutaneous blood supply, and healed by means of epithelialization. Swine have been extensively utilised for superficial and deep wound healing studies and can offer ample soft tissue coverage following a lower limb amputation. Development of a porcine model is important for continued understanding and improvement of weight-bearing transcutaneous osseointegration. Methods. Two male Yucatan mini-pigs (9 months, 36kg) were fit with transcutaneous osseointegrated prostheses using a single-stage transtibial amputation and prosthesis implantation procedure. The endo-prosthesis consisted of a cylindrical intraosseous threaded section and a smooth transcutaneous section. The transcutaneous sections were smooth to promote epithelialization and deter direct skin-implant adhesion. The implants were custom manufactured from medical grade Ti-6Al-4V alloy. The exo-prosthesis, consisting of an adjustable length leg and foot, was attached by clamp to the supercutaneous portion of the implant following either one or two days of sling constraint to limit initial weight-bearing. Various exo-prosthesis designs and configurations were trialed. The animals’ behavior and gait were closely observed. Weight-bearing was monitored using a force plate. At 5 and 8 weeks, clinical, microbiological, and histological data were examined to assess wound healing and infection at the skin-bone-implant interface. Results. The pigs demonstrated surprising agility and adaptability. They were able to successfully ambulate on three legs during the post-op period before weight-bearing was permitted. They adapted quickly to changes in exo-prosthesis design, position, and length. Although bacterial colonization was verified, neither of the animals exhibited clinical signs of infection over the respective eight and five week studies. Histological results indicated that there was no skin to implant adhesion but that epithelial growth was progressing towards the implant in one animal. Healing of the transcutaneous wound site showed substantial progress but a definitive skin seal was non-existent at the eight week time point. Discussion/Conclusion. This is likely the first animal model developed, having soft tissue characteristics similar to those found in humans, in which an axially-loaded, weight-bearing implant was successfully used. Results indicated that this porcine model offers many advantages over previous models for the development, evaluation, and comparison of the various techniques being advocated to achieve successful transcutaneous osseointegration in humans. The Yucatan miniature pig's ability to ambulate on three legs during the immediate post-operative period and quickly adjust to changes in the exo-prosthesis design, coupled with their physiological similarity to humans, makes them a valuable model for future studies

We used a knee-sparing distal femoral endoprosthesis in young patients with malignant bone tumours of the distal femur in whom it was possible to resect the tumour and to preserve the distal femoral condyles. The proximal shaft of the endoprosthesis had a coated hydroxyapatite collar, while the distal end had hydroxyapatite-coated extracortical plates to secure it to the small residual femoral condylar fragment. We reviewed the preliminary results of this endoprosthesis in eight patients with primary bone tumours of the distal femur. Their mean age at surgery was 17.years (14 to 21). The mean follow-up was 24 months (20 to 31). At final follow-up the mean flexion at the knee was 102° (20° to 120°) and the mean Musculoskeletal Tumour Society score was 80% (57% to 96.7%).

There was excellent osteointegration at the prosthesis-proximal bone interface with formation of new bone around the hydroxyapatite collar. The prosthesis allowed preservation of the knee and achieved a good functional result. Formation of new bone and remodelling at the interface make the implant more secure. Further follow-up is required to determine the long-term structural integrity of the prosthesis.