Suppressive antimicrobial therapy (SAT) is used worldwide for patients with a prosthetic joint infection (PJI but clear definitions or guidelines regarding the indications, antimicrobial strategy or treatment duration are currently lacking in the literature. The aim of this study was to identify the global differences in the clinical practice of SAT for PJI. An online survey was designed to investigate the current opinion on indication and treatment goals, preferred antimicrobial drugs, dosing and treatment duration and follow-up of patients with PJI on suppression. The survey was distributed using e-mail lists of several international bone and joint infection societies and study groups. Recipients were asked to share the survey with colleagues who were not a member of one of the societies but who were involved in PJI care.Aim
Method
Periprosthetic joinTt infection (PJI) remains an uncommon, yet devastating complication of total hip arthroplasty (THA) and total knee arthroplasty (TKA). Debridement with antibiotics and implant retention (DAIR) provides an alternative to staged revision. Chronic infection is considered to be a contraindication to DAIR, however, outcomes stratified by chronicity have not been documented. We performed a retrospective review of all DAIR cases performed at our institution between 2008–2015. Timeframe to treatment was categorized as acute (< 6 weeks since surgery), chronic (>6 weeks since surgery) or acute hematogenous (previously well-functioning prosthesis). Treatment failure was defined as reoperation during the first 90-days following DAIR. Univariate analysis (Mann-Whitney U and Chi-square; p<0.05) and generalized estimating equations (GEE) were used with multiple comparison adjustment by Tukey-Kramer method (α = 0.05).Introduction
Methods
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. 116 patients had 3-dimensional templating as part of their routine planning for THR (Optimized Ortho, Sydney). 96 patients from 3 surgeons (AS, JB, SM) received a blade stem (TriFit TS, Corin, UK) through a posterior approach. 18 patients received a fully HA-coated stem (MetaFix, Corin, UK) through a posterior approach by a single surgeon (WB). The anteversion of the native femoral neck was measured from a 3D reconstruction of the proximal femur. All patients received a post-operative CT scan which was superimposed onto the pre-op CT scan. The difference between native and achieved stem anteversion was then measured. As surgeons had differing philosophies around target stem anteversion, the differences amongst surgeons were also investigated.Introduction
Method
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). Fifty-nine patients had a pre-operative CT scan as part of their routine planning for THR. The patients were asked to lie in a comfortable position in the CT scanner. The internal/external rotation of the femur, described as the angle between the posterior condyles and the CT coronal plane, was measured. The native femoral neck anteversion, relative to the posterior condyles, was also determined. Identical measurements were performed at one-week post-op using the same CT methodology. The relationship between femoral IR/ER and femoral anteversion was studied pre- and post-op. Additionally, the effect of changing anteversion on the axial rotation of the femur was investigated.Introduction
Method
The prevalence of symptomatic osteoarthritis (OA) in the knee is 11–11% compared to 3.4–4.4% in the ankle. In addition to this, 70% of ankle arthritis is post-traumatic while the vast majority of knee arthritis is primary OA. Several reports have previously implicated biochemical differences in extracellular matrix composition between these joint cartilages; however, it is unknown whether there is an inherent difference in their transcriptome and how this might affect their respective functionality under load, inflammatory environment etc. Therefore, we have analysed the transcriptome of ankle and knee cartilage chondrocytes to determine whether this could account for the lower prevalence and altered aetiology of ankle OA. Human full-depth articular cartilage was taken from the talar domes (n=5) and the femoral condyles (n=5) following surgical amputation. RNA was extracted and next generation sequencing (NGS) performed using the NextSeq®500 system. Statistical analysis was performed to identify differentially regulated genes (p adj < 0.05). Data was analysed using Integrated Pathway Analysis software and genes of interest validated by quantitative PCR.Introduction
Methods
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 purpose of this study was to identify factors (radiographic and MRI) which may be important in determining whether a degenerative spondylolisthesis at L4/5 is mobile. We identified 60 consecutive patients with a degenerative spondylolisthesis(DS) at L4/5 and reviewed their imaging. Patients were separated into groups on the basis of whether the DS was mobile (group A) or non-mobile (Group B) when comparing the upright plain lumbar radiograph to the supine MRI. We assessed the lumbar lordosis, pelvic incidence, sacral slope, pelvic tilt, grade of the slip, facet angles at L4/5, facet tropism, facet effusion size, facet degenerative score (cartilage and sclerosis values) and disc degenerative score (Pfirrmann) at L4/5.Aim:
Method:
The Lenke Classification for adolescent idiopathic scoliosis (AIS) classifies curves as nonstructural if they reduce to less than 25° on bending radiographs. We aimed to establish whether there is a significant difference in curves assessed as structural/ nonstructural when comparing bending radiographs to forced traction radiographs. We undertook a retrospective database review of 100 consecutive AIS patients having undergone surgical correction by the 2 senior authors, together with radiographic review. Curves were classified according to the Lenke system including modifiers. Magnitude of the minor curves were compared on plain PA standing radiographs, bending radiographs and forced traction radiographs.Aim:
Methods:
To compare the degree of deformity correction achieved using cobalt chromium versus titanium alloy rods in patients with Adolescent Idiopathic Scoliosis. A retrospective comparison of two cohorts of patients with Adolescent Idiopathic Scoliosis treated with posterior segmental pedicle screw fixation using either Titanium or Cobalt Chromium rods. The radiographs of 50 patients treated before 2009 (Ti group) and 50 patients after 2009 (CoCr group) were reviewed for changes in: Main Coronal Curvature Sagittal Balance (C7 Plumb Line) Kyphosis (T5-12)Aim:
Method:
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.
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.
The Pipino prosthesis was introduced as an alternative to hip resurfacing because of its bone preserving capability. Preserving the femoral neck to a greater extent saves valuable bonestock for possible revision procedures. The stem (proximal 2/3) and acetabular cup are hydroxyapatite coated. Bearings were all either ceramic or metal on polyethylene. All procedures were performed or directly supervised by the senior author. Patients in the cohort were assessed pre-operatively, in the short term and the medium term using the Harris Hip Score(HHS). Hip radiographs were performed at medium term follow-up to assess for radiological signs of aseptic loosening. The study is based on a cohort of 70 patients, 34 male and 36 female with mean age of 52 (range 13-71). Followed up over a mean period of 43 months (range 17-60). 70 patients were contacted and 64 patients were reviewed. Four patients were lost to follow-up. Indications for surgery were Osteoarthritis (56); Rheumatoid arthritis (8); AVN (3); SUFE (2); Perthes (2); DDH (1); Psoriatic Arthropathy (1). The cohort’s preoperative HHS showed a mean 50.1 (range 25-88). This increased to a mean of 95.9 (range 55-100) in the short term review period, during the medium term review the mean 93.6 (range 63-100). With 82% of patients in the excellent group and 88% good to excellent group. At the final review there was one case of aseptic loosening (Cup) which required revision surgery. There were 2 dislocations and one intraoperative lateral femoral wall fracture and no cases of superficial or deep infection. In conclusion we believe that the Pipino collum femo-ris preserving total hip arthroplasty has excellent short and medium term results.
