Introduction

Appropriate prosthetic alignment is an important factor in maintaining stability and maximising the performance of the bearing after total hip replacement (THR). With a cementless component, the anteversion of the native femur has been shown to influence the anteversion of the prosthetic stem. However, the extent to which anteversion of a cementless stem can be adjusted from the native anteversion has seldom been reported. The aim of this study was to investigate the difference between native and stem anteversion with two different cementless stem designs.

Introduction

The posterior condylar axis of the knee is the most common reference for femoral anteversion. However, the posterior condyles, nor the transepicondylar axis, provide a functional description of femoral anteversion, and their appropriateness as the ideal reference has been questioned. In a natural standing positon, the femur can be internally or externally rotated, altering the functional anteversion of the native femoral neck or prosthetic stem. Uemura et al. found that the femur internally rotates by 0.4° as femoral anteversion increases every 1°. The aim of this study was to assess the relationship between femoral anteversion and the axial rotation of the femur before and after total hip replacement (THR).

The lifetime prevalence of symptomatic osteoarthritis at the knee is 50% osteoarthritis of the ankle occurs in only 1% of the population. This variation in prevalence has been hypothesised to result from the differential responsiveness of the joint cartilages to catabolic stimuli.

Human cartilage explants were taken from the talar domes (n=12) and the femoral condyles (n=7) following surgical amputation. Explants were cultured in the presence of either a combination of high concentration cytokines (TNFα, OSM, IL-1α) to resemble a post traumatic environment or low concentration cytokines to resemble a chronic osteoarthritic joint. Cartilage breakdown was measured by the percentage loss of Sulphated glycosaminoglycan (sGAG) from the explant to the media during culture. Expression levels of the pro-inflammatory molecules nitric oxide and prostaglandin E₂ were also measured.

Significantly more sGAG was lost from knee cartilage exposed to TNFα (22.2% vs 13.2%, P=0.01) and TNFα in combination with IL-1α (27.5% vs 16.0%, P=0.02) compared to the ankle; low cytokine concentrations did not affect sGAG release. Significantly more PGE₂ was produced by knee cartilage compared to ankle cartilage however no significant difference in nitrite production was noted.

Cartilage from the knee and ankle has a divergent response to stimulation by pro-inflammatory cytokines, with high concentrations of TNFα alone, or in combination with IL-1α amplifying cartilage degeneration. This differential response may account for the high prevalence of knee arthritis compared to ankle OA and provide a future pharmacological target to treat post traumatic arthritis of the knee.

Bertolotti first described articulation of the L5 transverse process with the sacrum as a cause of back pain in 1917. Since then little attention has been payed to these atypical articulations despite their high reported incidence.

Here we describe our early experience of surgical treatment and propose a validated CT based classification of lumbosacral segment abnormalities (LSSA).

400 lumbosacral CT scans were reviewed (NBT), a classification devised and incidence of abnormalities recorded. 40 patients were selected and 4 independent observers classified each scan. Case notes for all patients (C&V) who received steroid injections into or surgical excision of LSSAs were reviewed. Results as follows:

5 types of abnormality were identified.

Type 0 - normal

Type 1 - asymmetrical shortening of the iliolumbar ligament

Type 2 - transverse process of L5 within 2mm of the sacrum

Type 3 - diarthrodial joint (3A: no evidence of degeneration 3B: degenerative change)

Type 4 - transverse process and sacrum have fused

Type 5 - extends to L4

54.5% of patients had abnormalities. The kappa values for the intra-observer results were 0.69 to 0.88 and the inter-observer ratings gave a combined score of over 0.7 indicating substantial agreement.

Our CT classification of LSSAs is both straight forward to use and repeatable. The incidence of these abnormalities is higher in our population of CT scans compared to previous published series using plain radiographs. All patients treated with surgical excision of established articulations (Type 3A or above) reported good or excellent outcomes following excision.

The anatomy of the prevertebral region of the neck is of vital importance to orthopaedic surgeons when managing cervical spine trauma. Lateral radiographs are used in the acute assessment of this area as they are readily available and cost effectiveness. Thickening of the retropharyngeal space on a radiograph may be highly suggestive of serious and life-threatening pathologies. Accurate interpretation of radiological evidence is essential to assist the clinician in diagnosis. Current guidelines for radiological measurement state that these prevertebral soft tissues should not exceed 5mm at the midvertebral level of C3 and 20mm at C7. A ratio between soft tissue measurements and the width of the corresponding vertebra has also been championed as this takes into account magnification errors and variation in patient body habitus. Soft tissue measurements greater than 30% of the upper cervical vertebral bodies and greater than 100% of the lower cervical vertebral bodies are considered to be abnormal. The aim of this study was to assess reliability of current radiological guidelines on soft tissue measurement. A review of 200 consecutive normal lateral soft tissue cervical spine radiographs was undertaken. Patients were included if they were immobilised for blunt trauma and were aged 18 or older. Each patient included had cervical pathology excluded by a combination of clinical examination, flexion-extension views, CT and or MRI. Exclusion criteria included those patients with pre-existing cervical or retropharyngeal pathology, those who had been intubated or had a nasogastric tube passed. Two reviewers independently assessed soft tissue and bony widths at C3 and C7 using the PACs Software. All measurements were taken at the mid vertebral level, not at the end plates to ensure any anterior osteophytes did not create a falsely wide measurement. Plane film radiographs of 107 males and 93 females were included with an average age of 53. At the C3 level, mean soft tissue widths were 4.7mm ± 0.84mm SD and ranged from 2.7 to 7.4mm. The mean soft tissue width at C7 was 14.4mm ± 2.8mm SD with a range of 7.1 to 21.0 mm. Our results show 21.5% (43/200) of the patients exceeded the 5mm upper limit and 20% (40/200) exceeded the soft tissue to vertebra ratio at C3. Only 1% (2/200) of patients exceeded the upper limit of 20mm at C7 and only 2% (4/200) exceeded the soft tissue to vertebra ratio. The C3 guideline for maximum soft tissue widths has a poor specificity (78.5%) and the soft tissue to vertebral ratio at this level may also lead to further unnecessary investigation, as it too has a specificity of only 80%. However, the guidelines for PVST measurements at C7 are much more reliable with a specificity of 99.5% for the absolute measurement and 99% for the soft tissue to vertebra ratio. The ratio measurement has not conferred any significant diagnostic benefit over the static measurement. Current guidelines overestimate injuries at the C3 level but seem appropriate at the C7 level. There is no major benefit to using a ratio measurement over an absolute value.

Staphylococcus aureus is one of the leading causes of surgical site infection (SSI). Over the past decade there has been an increase in methicillin-resistant S. aureus (MRSA). This is a subpopulation of the bacterium with unique resistance and virulence characteristics. Nasal colonisation with either S. aureus or MRSA has been demonstrated to be an important independent risk factor associated with the increasing incidence and severity of SSI after orthopaedic surgery. Furthermore, there is an economic burden related to SSI following orthopaedic surgery, with MRSA-associated SSI leading to longer hospital stays and increased hospital costs. Although there is some controversy about the effectiveness of screening and eradication programmes, the literature suggests that patients should be screened and MRSA-positive patients treated before surgical admission in order to reduce the risk of SSI.

Cite this article: Bone Joint J 2013;95-B:4–9.

Nationally, experimental estimated Indigenous life expectancy was 59 years for Indigenous males (compared with 77 for all males) and 65 years for Indigenous females (compared with 82 years for all females). This is a difference of around 17 years for both males and females (ABS 2004).

The Australian Government has embarked on numerous educational and health campaigns addressing the disease processes that lead to such a stark difference in life expectancy. The results of these campaigns are evident, as the population of Indigenous Australians over 60 years of age has risen from 9968 (Census 1986) to 25604 (Census 2008). As a result, we are now beginning to see orthopaedic degenerative disease states such as osteoarthritis. This increase in the number of Iindigenous Australians suffering from osteoarthritis will result in a greater number of hip and knee joint arthroplasty for osteoarthritis. Although the largest populations of Indigenous patients reside in urban areas, notably Sydney (census count 41,800), Brisbane (41,400) and Perth (21,300), the Torres Strait region of Queensland has 83% of the Indigenous population in remote Australia (Census 2008).

This is reflected in the number of hip and knee joint arthroplasties performed through the orthopaedic department at the Cairns Base Hospital on indigenous patients, from a total of seven in 2001 to a total of 22 in 2008.

Retrospective analysis was conducted of those patients failing to attend their full complement of post-operative follow-up in the first year post total hip and knee joint arthroplasty for the eight year period from 2001 to 2008 at the Cairns Base Hospital. Within this period a total of 99 hip and knee arthroplasties were performed on indigenous patients. Over 30% of indigenous patients failed to attend their full complement of post-operative follow up in the first year post hip and knee joint arthroplasty.

Due to the increasing life expectancy of the indigenous population, more are presenting with orthopaedic degenerative disease states that require joint arthroplasty. The higher number of co-morbidities such as type II diabetes mellitus and peripheral vascular disease makes post operative follow up of the indigenous patient essential to avoid complications. The lack of follow up will undoubtedly lead to an inability to appropriately monitor the indigenous patient's recovery and/or decrease in morbidity post total hip and knee joint arthroplasty. Patient centered follow-up must be given greater consideration in relation to the Australian indigenous population such as an increase in outreach services, the provision of orthopaedic follow up by the local health practitioners in the rural and remote setting, maintaining up to date contact details along with affording the indigenous patient greater access to transport so as to improve follow up.