Aims

Hip arthroplasty aims to accurately recreate joint biomechanics. Considerable attention has been paid to vertical and horizontal offset, but femoral head centre in the anteroposterior (AP) plane has received little attention. This study investigates the accuracy of restoration of joint centre of rotation in the AP plane.

Aims

Our aim in this study was to describe a continuing review of 11 total hip arthroplasties using 22.225 mm Alumina ceramic femoral heads on a Charnley flanged femoral component, articulating against a silane crosslinked polyethylene.

Introduction

Cross linked polyethylene (XLPE) has gained popularity as a bearing surface of choice for younger patients despite only medium term results being available for wear rates. Concern remains regarding the long-term stability and durability of these materials. In order to address these issues we present the longest radiological and clinical follow-up of XLPE.

We reviewed the literature on the currently available choices of bearing surface in total hip replacement (THR). We present a detailed description of the properties of articulating surfaces review the understanding of the advantages and disadvantages of existing bearing couples. Recent technological developments in the field of polyethylene and ceramics have altered the risk of fracture and the rate of wear, although the use of metal-on-metal bearings has largely fallen out of favour, owing to concerns about reactions to metal debris. As expected, all bearing surface combinations have advantages and disadvantages. A patient-based approach is recommended, balancing the risks of different options against an individual’s functional demands.

Cite this article: Bone Joint J 2014;96-B:147–56.

Introduction

There are over 110 special tests described in the literature for clinical examination of the shoulder, but there is no general consensus as to which of these are the most appropriate to use. Individual opinion appears to dictate clinical practice. Rationalising which tests and clinical signs are the most useful would not only be helpful for trainees, but would also improve day to day practice and promote better communication and understanding between clinicians.

Introduction

Four weeks after the earthquake in Kashmir, multidisciplinary surgical teams were organised within the UK (MiST). The aim was to help with disaster victims who had been transferred to Rawalipindi. We reviewed the work carried by one such team from the 5-18 November 2005.

This is a retrospective review of the results of the Acclaim total elbow replacement in 11 older patients aged ≥ 65 years with primary osteoarthritis of the elbow, with a mean follow-up of 57.6 months (30 to 86.4).

Significant reductions in pain and improvement in range of movement and function were recorded. Radiological review revealed two patients with 1 mm lucencies in a single zone, and one patient with 1 mm lucencies in two zones. No components required revision. There were no deep infections, dislocations or mechanical failures. Complications included one intra-operative medial condylar fracture and one post-operative transient ulnar neuropathy, which resolved.

This study demonstrates that the Acclaim prosthesis provides good symptomatic relief and improvement of function in patients with primary osteoarthritis, with low rates of loosening or other complications. This prosthesis can therefore be considered for patients aged ≥ 65 years with primary osteoarthritis of the elbow.

We report the effect of padding on the efficiency of the pneumatic tourniquet for the upper limb. Varying thicknesses of two commercially-available types of orthopaedic padding (Cellona and Velband) were applied to the arms of 20 volunteers, with three pressure transducers placed directly beneath the padding. A tourniquet was positioned over the padding and inflated to 220 mmHg.

Significant reductions in the transmitted pressure were recorded from the transducers with both padding materials. With eight layers of padding, reductions in pressure of 13% (1% to 26%) and 18% (7% to 35%) were seen with Cellona and Velband, respectively. The reduction in pressure with Velband padding correlated with increasing arm circumference (Pearson’s correlation coefficient 0.711, p < 0.001).

Studies to date have examined how arm circumference affects the required tourniquet inflation pressure. Our study is the first to investigate the effect of the padding and the findings suggest that using more than two layers results in a significant reduction in the transmitted pressure.

Background: Current treatments for Low back pain (LBP) are often empirical and few directed at the underlying disorder, altered discal cell metabolism, which precipitates the problem. The use of gene therapy to manipulate discal metabolism to treat LBP is an interesting possibility. The Intervertebral disc (IVD) is a therapeutic target in LBP, and one approach to gene therapy would be to isolate IVD chondrocytes (IVDC) and transfer genes Ex Vivo into these cells. Subsequent reinjection of these genetically altered cells into the lumbar IVD, would permit the expression of the trans-gene in vivo, generating the therapeutic protein within the IVD.

Methods: To test the viability of this approach, we isolated human IVDC from patients undergoing surgery, grew them Ex vivo and transfected them with the marker gene LacZ, using an adenovirus vector and the CMV promoter. Expression of the gene was then measured using X-gal staining for the gene product ~-galactosidase.

Results: IVDC infected with adenovirus/CMV-LacZ showed maximal LacZ expression 2 days post infection, with almost 50% of cells displaying X-gal positivity within monolayer cultures and 100% infection within alginate culture, gene expression was maintained up to 4 weeks and control cultures showed no LacZ expression.

Conclusion: This study shows that human IVDC can be transfected with a foreign gene using the adenovirus vector. The gene transduction of a therapeutic gene into IVDC, could provide long lasting effect. In addition the use of inducible promoters could allow for the autoregulation of gene expression.

Background: Low back pain (LBP) is a major cause of disability. However, current treatments are often empirical and few are directed at the underlying disorder, altered discal cell metabolism, which precipitates the problem. The use of gene therapy to manipulate discal metabolism to treat LBP is an interesting possibility. The Intervertebral disc (IVD) is a therapeutic target in LBP, and one approach to gene therapy would be to isolate IVD chondrocytes (IVDC) and transfer genes ex vivo into these cells. Subsequent reinjection of these genetically altered cells into the lumbar IVD, would permit the expression of the transgene in vivo, generating the therapeutic protein within the IVD.

Methods: To test the viability of this approach, we isolated human IVDC from patients undergoing surgery, grew them ex vivo and transfected them with the marker gene LacZ, using an adenovirus vector and the CMV promoter. Expression of the gene was then measured using X-gal staining for the gene product _-galactosidase. Post infection, some cells were treated with forskolin for 24 hours to assess whether expression of the transgene could be manipulated.

Results: IVDC infected with adenovirus/CMV-LacZ showed maximal LacZ expression 2 days post infection, with almost 50% of cells displaying X-gal positivity. Cells maintained a low level of expression for the remaining 12 days of the study. Control cultures showed no LacZ expression. Cells treated with forskolin after infection with adenovirus/CMV-LacZ exhibited 4 times the level of _-galactosidase activity seen in unstimulated cultures.

Conclusion: This study shows that human IVDC can be transfected with a foreign gene using the adenovirus vector. The gene transduction of a therapeutic gene into IVDC could provide a long lasting effect. In addition, the use of inducible promoters could allow for the autoregulation of gene expression.

Purpose and Background: There is increasing evidence that events within the diseased intervertebral disc (IVD) are mediated by locally synthesised cytokines. A prominent histological, imaging and surgical feature of IVD disease is degradation of the cartilaginous discal matrix. Whilst the mechanism by which this is mediated is unknown, in other situations where connective tissues are degraded degradation is the result of production of matrix-degrading enzymes by local connective tissue cells stimulated by cytokines, particularly the beta isoform of interleukin-1 (IL-1β). Included amongst these disorders is osteoarthritis (OA) of diarthrodial joints. OA has many similarities to the discal “degeneration” seen in mechanical back pain syndromes. In the current study, we have used a combination of in-situ techniques to establish if IL-1β is responsible for stimulating matrix degradation in the IVD.

Methods: Using a combination of radioactive in-situ hybridisation (ISH) and competitive in situ zymography (ISZ) we have studied expression of IL-1β and IL-1R – its type 1 receptor (ISH) and matrix degradation (ISZ) in five diseased lumbar IVD taken at spinal fusion surgery and 10 cadaveric IVD (five normal and five diseased). The nucleus pulposus (NP) was separated from the annulus fibrosus and diced into 0.5cm cubes. Half the cubes (typically three) were fixed in formalin and processed into paraffin wax for ISH, and half were used for ISZ. For ISH, 5 μm sections of paraffin-embedded tissue were reacted with cDNA probes radiolabelled with 35S to 580 and 530 base segments of the IL-1β and IL-1R molecules. Hybridisation was disclosed using autoradiography. For ISZ, 50 μm vibratome sections were placed into wells on microscope slides precoated with gelatin. Sections were incubated for 10 days, half in culture medium and half in medium supplemented with human recombinant IL-1 receptor antagonist (IL-1Ra – an inhibitor of IL-1). Sections were photographed at daily intervals to detect evidence of gel degradation.

Results: Chondrocytes within patient and cadaveric diseased but not normal discs expressed mRNA for both IL-1β and IL-1R. By ISZ, the same cells degraded gelatin. Degradation was inhibited by recombinant IL-1Ra.

Conclusion: This study shows that chondrocytes of diseased discs express IL-1 and its receptor. The same cells produced matrix-degrading enzymes by a mechanism that can be inhibited by the IL-1 inhibitor IL-1Ra. IL-1 is a potential therapeutic target for the management of IV disc disease.