Hip implant retrieval analysis is the most important source of insight into the performance of new materials and designs of hip arthroplasties. Even the most rigorous in vitro testing will not accurately simulate the behavior of implant materials and new designs of prosthetic arthroplasties. Retrieval analysis has revealed such factors as the effects of gamma-in-air sterilisation of polyethylene, fatigue failure mechanisms of polymethylmethacrylate bone cement, fretting corrosion of Morse taper junctions, third body wear effects of both hard-on-hard and hard-on-soft bearing couples, and the effects of impingement of components on the full spectrum of bearing surfaces, none of which was predicted by pre-implantation in vitro testing of these materials and combinations. The temporal sequence of the retrieval process is approximately six years from first implantation through retrieval analysis, laboratory investigation, and publication of results, and thus, in addition to rigorous clinical evaluation, represents the true development and insight cycle for new designs and materials

We undertook a review of the literature relating to the two basic stem designs in use in cemented hip replacement, namely loaded tapers or force-closed femoral stems, and the composite beam or shape-closed designs. The associated stem fixation theory as understood from in vitro studies and finite element modelling were examined with reference to the survivorship results for each of the concepts of fixation.

It is clear that both design principles are capable of producing successful long-term results, providing that their specific requirements of stem metallurgy, shape and surface finish, preparation of the bone and handling of the cement are observed.

Periprosthetic joint infection (PJI) is one of the most dreaded complications after arthroplasty surgery; thus numerous approaches have been undertaken to equip metal surfaces with antibacterial properties. Due to its antimicrobial effects, silver is a promising coating for metallic surfaces, and several types of silver-coated arthroplasty implants are in clinical use today. However, silver can also exert toxic effects on eukaryotic cells both in the immediate vicinity of the coated implants and systemically. In most clinically-used implants, silver coatings are applied on bulk components that are not in direct contact with bone, such as in partial or total long bone arthroplasties used in tumour or complex revision surgery. These implants differ considerably in the coating method, total silver content, and silver release rates. Safety issues, such as the occurrence of argyria, have been a cause for concern, and the efficacy of silver coatings in terms of preventing PJI is also controversial. The application of silver coatings is uncommon on parts of implants intended for cementless fixation in host bone, but this option might be highly desirable since the modification of implant surfaces in order to improve osteoconductivity can also increase bacterial adhesion. Therefore, an optimal silver content that inhibits bacterial colonization while maintaining osteoconductivity is crucial if silver were to be applied as a coating on parts intended for bone contact. This review summarizes the different methods used to apply silver coatings to arthroplasty components, with a focus on the amount and duration of silver release from the different coatings; the available experience with silver-coated implants that are in clinical use today; and future strategies to balance the effects of silver on bacteria and eukaryotic cells, and to develop silver-coated titanium components suitable for bone ingrowth. Cite this article: Bone Joint J 2021;103-B(3):423–429

Over the past 30 years there have been many improvements in implant fixation, correction of deformity, improved polyethylene wear, and survival after knee replacement. The work over the last decade has focused on less invasive surgical techniques, multimodal pain management protocols, more rapid functional recovery and reduced length of stay, aiming to minimise the side effects of treatment while maintaining function and implant durability. When combined and standardised these pre-, intra- and post-operative factors have now facilitated outpatient knee replacement procedures for unicompartmental replacement, patella femoral arthroplasty and total knee replacement (TKR). We have found liposomal bupivacaine, with potential for longer therapeutic action, to be a helpful adjunct and describe our current pain management program. The next step in our multimodal program is to improve the duration of patient satisfaction and reduce cost and length of stay after TKR. Cite this article: Bone Joint J 2014;96-B(11 Suppl A):7–9

Since 1996 more than one million metal-on-metal articulations have been implanted worldwide. Adverse reactions to metal debris are escalating. Here we present an algorithmic approach to patient management. The general approach to all arthroplasty patients returning for follow-up begins with a detailed history, querying for pain, discomfort or compromise of function. Symptomatic patients should be evaluated for intra-articular and extra-articular causes of pain. In large head MoM arthroplasty, aseptic loosening may be the source of pain and is frequently difficult to diagnose. Sepsis should be ruled out as a source of pain. Plain radiographs are evaluated to rule out loosening and osteolysis, and assess component position. Laboratory evaluation commences with erythrocyte sedimentation rate and C-reactive protein, which may be elevated. Serum metal ions should be assessed by an approved facility. Aspiration, with manual cell count and culture/sensitivity should be performed, with cloudy to creamy fluid with predominance of monocytes often indicative of failure. Imaging should include ultrasound or metal artifact reduction sequence MRI, specifically evaluating for fluid collections and/or masses about the hip. If adverse reaction to metal debris is suspected then revision to metal or ceramic-on-polyethylene is indicated and can be successful. Delay may be associated with extensive soft-tissue damage and hence poor clinical outcome

Failure of bone repair is a challenging problem in the management of fractures. There is a limited supply of autologous bone grafts for treating nonunions, with associated morbidity after harvesting. There is need for a better source of cells for repair. Mesenchymal stem cells (MSCs) hold promise for healing of bone because of their capacity to differentiate into osteoblasts and their availability from a wide variety of sources. Our review aims to evaluate the available clinical evidence and recent progress in strategies which attempt to use autologous and heterologous MSCs in clinical practice, including genetically-modified MSCs and those grown on scaffolds. We have compared various procedures for isolating and expanding a sufficient number of MSCs for use in a clinical setting. There are now a number of clinical studies which have shown that implantation of MSCs is an effective, safe and durable method for aiding the repair and regeneration of bone

The survivorship of contemporary resurfacing arthroplasty of the hip using metal-on-metal bearings is better than that of first generation designs, but short-term failures still occur. The most common reasons for failure are fracture of the femoral neck, loosening of the component, osteonecrosis of the femoral head, reaction to metal debris and malpositioning of the component. In 2008 the Australian National Joint Registry reported an inverse relationship between the size of the head component and the risk of revision in resurfacing hip arthroplasty. Hips with a femoral component size of ≤ 44 mm have a fivefold increased risk of revision than those with femoral components of ≥ 55 mm irrespective of gender. We have reviewed the literature to explore this observation and to identify possible reasons including the design of the implant, loading of the femoral neck, the orientation of the component, the production of wear debris and the effects of metal ions, penetration of cement and vascularity of the femoral head. Our conclusion is that although multifactorial, the most important contributors to failure in resurfacing arthroplasty of the hip are likely to be the design and geometry of the component and the orientation of the acetabular component

The management of bone loss in revision replacement of the knee remains a challenge despite an array of options available to the surgeon. Bone loss may occur as a result of the original disease, the design of the prosthesis, the mechanism of failure or technical error at initial surgery. The aim of revision surgery is to relieve pain and improve function while addressing the mechanism of failure in order to reconstruct a stable platform with transfer of load to the host bone. Methods of reconstruction include the use of cement, modular metal augmentation of prostheses, custom-made, tumour-type or hinged implants and bone grafting. The published results of the surgical techniques are summarised and a guide for the management of bone defects in revision surgery of the knee is presented

Despite advances in the prevention and treatment of osteoporotic fractures, their prevalence continues to increase. Their operative treatment remains a challenge for the surgeon, often with unpredictable outcomes. This review highlights the current aspects of management of these fractures and focuses on advances in implant design and surgical technique

A modular femoral head–neck junction has practical advantages in total hip replacement. Taper fretting and corrosion have so far been an infrequent cause of revision. The role of design and manufacturing variables continues to be debated. Over the past decade several changes in technology and clinical practice might result in an increase in clinically significant taper fretting and corrosion. Those factors include an increased usage of large diameter (36 mm) heads, reduced femoral neck and taper dimensions, greater variability in taper assembly with smaller incision surgery, and higher taper stresses due to increased patient weight and/or physical activity. Additional studies are needed to determine the role of taper assembly compared with design, manufacturing and other implant variables.

Cite this article: Bone Joint J 2013;95-B, Supple A:3–6.

Most proximal humeral fractures are stable injuries of the ageing population, and can be successfully treated non-operatively. The management of the smaller number of more complex displaced fractures is more controversial and new fixation techniques have greatly increased the range of fractures that may benefit from surgery.

This article explores current concepts in the classification and clinical aspects of these injuries, reviewing the indications, innovations and outcomes for the most common methods of treatment.

This paper describes the presence of tenodesis effects in normal physiology and explores the uses of operative tenodesis in surgery of the upper limb.

Neurological conditions affecting the hip pose a considerable challenge in replacement surgery since poor and imbalanced muscle tone predisposes to dislocation and loosening. Consequently, total hip replacement (THR) is rarely performed in such patients. In a systematic review of the literature concerning THR in neurological conditions, we found only 13 studies which described the outcome. We have reviewed the evidence and discussed the technical challenges of this procedure in patients with cerebral palsy, Parkinson’s disease, poliomyelitis and following a cerebrovascular accident, spinal injury or development of a Charcot joint. Contrary to traditional perceptions, THR can give a good outcome in these often severly disabled patients.

Articular cartilage repair remains a challenge to surgeons and basic scientists. The field of tissue engineering allows the simultaneous use of material scaffolds, cells and signalling molecules to attempt to modulate the regenerative tissue. This review summarises the research that has been undertaken to date using this approach, with a particular emphasis on those techniques that have been introduced into clinical practice, via in vitro and preclinical studies.

The management of patients with a painful total knee replacement requires careful assessment and a stepwise approach in order to diagnose the underlying pathology accurately. The management should include a multidisciplinary approach to the patient’s pain as well as addressing the underlying aetiology. Pain should be treated with appropriate analgesia, according to the analgesic ladder of the World Health Organisation. Special measures should be taken to identify and to treat any neuropathic pain. There are a number of intrinsic and extrinsic causes of a painful knee replacement which should be identified and treated early. Patients with unexplained pain and without any recognised pathology should be treated conservatively since they may improve over a period of time and rarely do so after a revision operation.

Although mechanical stabilisation has been a hallmark of orthopaedic surgical management, orthobiologics are now playing an increasing role. Platelet-rich plasma (PRP) is a volume of plasma fraction of autologous blood having platelet concentrations above baseline. The platelet α granules are rich in growth factors that play an essential role in tissue healing, such as transforming growth factor-β, vascular endothelial growth factor, and platelet-derived growth factor. PRP is used in various surgical fields to enhance bone and soft-tissue healing by placing supraphysiological concentrations of autologous platelets at the site of tissue damage. The easily obtainable PRP and its possible beneficial outcome hold promise for new regenerative treatment approaches.

The aim of this literature review was to describe the bioactivities of PRP, to elucidate the different techniques for PRP preparation, to review animal and human studies, to evaluate the evidence regarding the use of PRP in trauma and orthopaedic surgery, to clarify risks, and to provide guidance for future research.

Methicillin-resistant Staphylococcus aureus (MRSA) has become a ubiquitous bacterium in both the hospital and community setting. There are two major subclassifications of MRSA, community-acquired and healthcare-acquired, each with differing pathogenicity and management. MRSA is increasingly responsible for infections in otherwise healthy, active adults. Local outbreaks affect both professional and amateur athletes and there is increasing public awareness of the issue. Health-acquired MRSA has major cost and outcome implications for patients and hospitals. The increasing prevalence and severity of MRSA means that the orthopaedic community should have a basic knowledge of the bacterium, its presentation and options for treatment.

This paper examines the evolution of MRSA, analyses the spectrum of diseases produced by this bacterium and presents current prevention and treatment strategies for orthopaedic infections from MRSA.

The advent of computer-assisted knee replacement surgery has focused interest on the alignment of the components. However, there is confusion at times between the alignment of the limb as a whole and that of the components. The interaction between them is discussed in this article. Alignment is expressed relative to some reference axis or plane and measurements will vary depending on what is selected as the reference. The validity of different reference axes is discussed. Varying prosthetic alignment has direct implications for surrounding soft-tissue tension. In this context the interaction between alignment and soft-tissue balance is explored and the current knowledge of the relationship between alignment and outcome is summarised.

This article considers the establishment, purpose and conduct of knee arthroplasty registers using the Swedish register as an example. The methods of collection of appropriate data, the cost, and the ways in which this information may be used are considered.

Polymethylmethacrylate remains one of the most enduring materials in orthopaedic surgery. It has a central role in the success of total joint replacement and is also used in newer techniques such as percutaneous vertebroplasty and kyphoplasty.

This article describes the current uses and limitations of polymethylmethacrylate in orthopaedic surgery. It focuses on its mechanical and chemical properties and links these to its clinical performance. The behaviour of antibiotic-loaded bone cement are discussed, together with areas of research that are now shedding light upon the behaviour of this unique biomaterial.