Basic Science Considerations in Primary Total Hip Replacement Arthroplasty

Total Hip Replacement is one of the most common operations performed in the developed world today. An increasingly ageing population means that the numbers of people undergoing this operation is set to rise. There are a numerous number of prosthesis on the market and it is often difficult to choose between them. It is therefore necessary to have a good understanding of the basic scientific principles in Total Hip Replacement and the evidence base underpinning them. This paper reviews the relevant anatomical and biomechanical principles in THA. It goes on to elaborate on the structural properties of materials used in modern implants and looks at the evidence base for different types of fixation including cemented and uncemented components. Modern bearing surfaces are discussed in addition to the scientific basis of various surface engineering modifications in THA prostheses. The basic science considerations in component alignment and abductor tension are also discussed. A brief discussion on modular and custom designs of THR is also included. This article reviews basic science concepts and the rationale underpinning the use of the femoral and acetabular component in total hip replacement

Outcomes of cartilage repair techniques for chondral injury in the hip-a systematic review.

OBJECTIVE/PURPOSE: The aim of the study was to assess the options of treatment and their related outcomes for chondral injuries in the hip based on the available evidence whilst highlighting new and innovative techniques. METHODS: A systematic review of the literature from PubMed (Medline), EMBASE, Google Scholar, British Nursing Index (BNI), Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Allied and Complementary Medicine Database (AMED) was undertaken from their inception to March 2017 using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Clinical outcome studies, prospective/retrospective case series and case reports that described the outcome of cartilage repair technique for the chondral injury in the hip were included. Studies on total hip replacement, animal studies, basic studies, trial protocols and review articles were excluded. RESULTS: The systematic review found 21 relevant papers with 596 hips. Over 80% of the included studies were published in or after 2010. Most studies were case series or case reports (18 studies, 85.7%). Arthroscopy was used in 11 studies (52.4%). The minimum follow-up period was six months. Mean age of the participants was 37.2 years; 93.5% of patients had cartilage injuries of the acetabulum and 6.5% of them had injuries of the femoral head. Amongst the 11 techniques described in the systematic review, autologous matrix-induced chondrogenesis, osteochondral autograft transplantation and microfracture were the three frequently reported techniques. CONCLUSION: Over ten different techniques are available for cartilage repair in the hip, and most of them have good short- to medium-term outcomes. However, there are no robust comparative studies to assess superiority of one technique over another, and further research is required in this arena

Comparative genetic structure of two co-occurring tree species, Maclura pomifera (Moraceae) and Gleditsia triacanthos (Leguminosae)

Maclura pomifera, an autotetraploid, and Gleditsia triacanthos, a diploid, are ecologically similar dioecious tree species that often co-occur in early successional habitats throughout the mid-western United States. We studied levels of genetic diversity and patterns of genetic structure for four polymorphic enzyme loci of M. pomifera and 16 polymorphic enzyme loci of G. triacanthos from a single population in eastern Kansas. Levels of expected heterozygosity were high for both species, averaging 0.725 for M. pomifera and 0.366 for G. triacanthos. Although genotypes for nearly all G. triacanthos loci were in Hardy-Weinberg frequencies, three of four M. pomifera loci deviated from equilibrium expectations. Two aspects of genetic structure were explored. First, the extent of clonal growth was estimated by comparing genotypes of stems within 50 G. triacanthos and 32 M. pomifera clumps. The great majority of clumps contained more than one genotype, and in many clumps, all stems were genetically unique. Secondly, as revealed by spatial autocorrelation analyses, genetic substructure was very local for both species, with significant positive autocorrelation occurring only within clumps of individuals or among near neighbours. We argue that this pattern of spatial structure for both species results from extremely local seed dispersal and establishment of individuals from the same multiseeded fruit