Ceramic bearings have several desirable properties, such as resistance to wear, hardness, and biocompatibility, that favour it as an articulating surface in hip arthroplasty. However, ceramic fracture remains a concern. We have reviewed the contemporary literature, addressing the factors that can influence the incidence of ceramic bearing surface fracture. Cite this article:
Aims. Instability remains a challenging problem in both primary and
revision total hip arthroplasty (THA). Dual mobility components
confer increased stability, but there are concerns about the unique
complications associated with these designs, as well as the long-term
survivorship. Materials and Methods. We performed a systematic review of all English language articles
dealing with dual mobility THAs published between 2007 and 2016
in the MEDLINE and Embase electronic databases. A total of 54 articles
met inclusion criteria for the final analysis of primary and revision
dual mobility THAs and dual mobility THAs used in the treatment
of fractures of the femoral neck. We analysed the survivorship and
rates of aseptic loosening and of intraprosthetic and extra-articular
dislocation. Results. For the 10 783 primary dual mobility THAs, the incidence of aseptic
loosening was 1.3% (142 hips); the rate of intraprosthetic dislocation
was 1.1% (122 hips) and the incidence of extra-articular dislocation
was 0.46% (41 hips). The overall survivorship of the acetabular
component and the dual mobility components was 98.0%, with all-cause revision
as the endpoint at a mean follow-up of 8.5 years (2 to 16.5). For the 3008 revision dual mobility THAs, the rate of aseptic
acetabular loosening was 1.4% (29 hips); the rate of intraprosthetic
dislocation was 0.3% (eight hips) and the rate of extra-articular
dislocation was 2.2% (67 hips). The survivorship of the acatabular
and dual mobility components was 96.6% at a mean of 5.4 years (2
to 8). For the 554 dual mobility THAs which were undertaken in patients
with a fracture of the femoral neck, the rate of intraprosthetic
dislocation was 0.18% (one hip), the rate of extra-articular dislocation
was 2.3% (13 hips) and there was one aseptic loosening. The survivorship
was 97.8% at a mean of 1.3 years (0.75 to 2). Conclusion. Dual mobility
Pathological assessment of periprosthetic tissues is important, not only for diagnosis, but also for understanding the pathobiology of implant failure. The host response to wear particle deposition in periprosthetic tissues is characterised by cell and tissue injury, and a reparative and inflammatory response in which there is an innate and adaptive immune response to the material components of implant wear. Physical and chemical characteristics of implant wear influence the nature of the response in periprosthetic tissues and account for the development of particular complications that lead to implant failure, such as osteolysis which leads to aseptic loosening, and soft-tissue necrosis/inflammation, which can result in pseudotumour formation. The innate response involves phagocytosis of implant-derived wear particles by macrophages; this is determined by pattern recognition receptors and results in expression of cytokines, chemokines and growth factors promoting inflammation and osteoclastogenesis; phagocytosed particles can also be cytotoxic and cause cell and tissue necrosis. The adaptive immune response to wear debris is characterised by the presence of lymphoid cells and most likely occurs as a result of a cell-mediated hypersensitivity reaction to cell and tissue components altered by interaction with the material components of particulate wear, particularly metal ions released from cobalt-chrome wear particles. Cite this article: Professor N. A. Athanasou. The pathobiology and pathology of aseptic implant failure.
Primary total knee arthroplasty (TKA) is a reliable
procedure with reproducible long-term results. Nevertheless, there
are conditions related to the type of patient or local conditions
of the knee that can make it a difficult procedure. The most common
scenarios that make it difficult are discussed in this review. These
include patients with many previous operations and incisions, and
those with severe coronal deformities, genu recurvatum, a stiff knee,
extra-articular deformities and those who have previously undergone
osteotomy around the knee and those with chronic dislocation of
the patella. Each condition is analysed according to the characteristics of
the patient, the pre-operative planning and the reported outcomes. When approaching the difficult primary TKA surgeons should use
a systematic approach, which begins with the review of the existing
literature for each specific clinical situation. Cite this article:
Periprosthetic joint infection (PJI) is one of
the most feared and challenging complications following total knee arthroplasty.
We provide a detailed description of our current understanding regarding
the management of PJI of the knee, including diagnostic aids,
pre-operative planning, surgical treatment, and outcome. Cite this article: