Abstract

Abstract

Abstract

The NZ Standards of Service Provision for Sarcoma patients were developed by the NZ Sarcoma working group and published by the Ministry of Health (MOH) in 2013. Although not formally enacted by the MOH we aimed to determine the impact of these published standards and referral pathways on disease-specific survival of patients with soft-tissue sarcoma in NZ.

The Middlemore Musculoskeletal Tumour Unit database was searched. Patients referred for treatment in our centre with a diagnosis of soft tissue sarcoma in the five-year period before (n=115) and after (n=155) were included. We excluded patients with bone sarcomas and retroperitoneal soft tissue sarcomas.

The rate of referral after inappropriate treatment reduced after implementation of the Standards (24% vs 12%, p=0.010). The number of patients referred with tumours larger than 50mm decreased (74.8% vs 72.3%, p=0.021) and fewer had metastases at diagnosis (11.3% vs 3.2%, p=0.017). Mortality was lower in the group after introduction of the Standards (45% vs 30%, p=0.017). The estimated disease-specific survival curve between the two groups shows a trend towards increased survival in the post-standards group, although not reaching statistical significance. Local recurrence rate and metastasis rate after definitive treatment were similar between the two groups. Patients had a shorter duration of symptoms before referral in the post-Standards group although this was not statistically significant.

Since implementation of the Standards, patients have been referred more promptly, with fewer inappropriate treatments. The time to mortality curve indicates a trend towards improved disease-specific survival. We conclude that the pathway for investigation and referral for this condition has become clearer, supporting the ongoing use of the Sarcoma Standards, and that these should be formally implemented by the MOH.

With increasing numbers of total joint arthroplasties being performed, peri-prosthetic fracture incidence is rising, and operative management remains the gold standard. Short-term survivorship up to 12 months has been well-documented but medium to long-term is almost unknown. We present survivorship review from a district general hospital, undertaking 800 primary hip and knee arthroplasties per year. Patients with peri-prosthetic fractures and background total knee replacements were identified using our computer database between 2006–2011. All patients were operated on our site; methods used include open reduction, internal fixation (ORIF) using Axsos (Stryker Newbury) locking plates (28), intra-medullary nailing (1) or complex revision (6) depending on fracture and patient factors and surgeon's preference. Mortality was assessed at 30 days, 12 months and 5 years. Thirty-four patients were identified with a 7:1 female to male ratio and mean age of 76. 75% of patients had their primary arthrodesis at our hospital. There was only 1 plate failure noted requiring revision plating. Mortality at 30 days, 12 months and 5 years were 3.2, 12.5% and 50% respectively. When compared to the literature our time interval from index surgery to fracture is considerably longer (115 vs 42 months). Further multi-centre reviews are required to further asses this unexpected finding. Overall mortality is better than our hip fracture cohort, suggesting that good results can be achieved in District Hospital. The longer-term results are encouraging and can act as a guide for patients with this injury. We recommend that patients are managed in consultant-led, multi-disciplinary teams.

The medical model of history, examination and investigation forms the bedrock of diagnosis and management of all patients. The essence is the recognition of patterns of symptoms and signs. In the modern era there are an increasing number of non-medical resources ranging from web-based information, computer diagnostic aids and non-specialist healthcare professionals to provide a diagnosis and commence management of a wide range of conditions, including knee problems. We analysed the quality and patterns of clinical presentation in order to answer the question how closely clinical symptoms and examination findings correlate to diagnosis based on MRI scan and/or arthroscopic findings. The analysis was a dataset of a consecutive series of patients, aged 18 to 45, with no past history of knee problems or end stage arthritis, presenting to a single specialist triage physiotherapist, working within an integrated knee service, who fully completed a standardised knee assessment proforma of presenting symptoms and signs at a large district general hospital. The study comprises 86 patients and 98 knees. We analysed this data based on diagnostic findings of MRI scan or arthroscopy to provide definitive intra-articular diagnosis. Based on standard textbook descriptions of common presentations, we went on to define the patients' presentation history and examination as typical or atypical, with typical meaning the symptoms and signs correlated with the diagnosis. The null hypothesis is that patients have a high chance of typical presentations for common knee conditions. In the 75% of patients with a significant intra-articular pathology we found the majority had chondral rather than meniscal tears 1.7 to 1. Forty four percent of patients had atypical symptoms and 71% had atypical clinical signs, 30% and only 26% of the cohort had both typical symptoms and signs together, reflecting a surprisingly low positive predictive probability of symptoms and signs in this group of patients, particularly those with chondral lesions which was 44%. In this cohort, 57% of the cohort has 3 or more multiple diagnoses. In the diagnostically normal group, 43% had symptoms and signs typical for a meniscal tear. We conclude that clinical symptoms and signs surprisingly inaccurate in guiding intra-articular pathology within the knee, even in a sub-set considered the easy and accurate to assess. The number of multiple diagnoses and the incidence of false positive results also means that simplistic interpretations of non-definitive diagnoses and linear causation of pain pathways should be treated cautiously.

A number of studies suggest revision of unicompartmental knee replacement (UKR) to total knee replacement (TKR) is straightforward. We hypothesise that this is not always the case in terms of complexity, cost and clinical outcome.

We identified 23 consecutive patients revised from UKR to TKR by 2 consultant surgeons (2005–2008). These were matched by age, sex and comorbidity to a cohort of primary TKRs (42 patients) performed during the same period. Data were collected regarding demographics, cost (surgical time & implants) and 1 & 5-year follow-up of clinical outcome (OKS) and outpatients attended.

There was no statistically significant difference in cost of implants for revision UKR to TKR vs. primary TKR (p=0.08), however operative time was significantly higher in the revision group. One year mean OKS was significantly higher in the primary TKR group (mean 30 vs. 23 p=0.03), but 5-year follow up showed no significant difference (mean OKS 27 vs. 32 p=0.20). The revision group had statistically significantly greater number of follow-up appointments (mean 6 Vs. 2 p<0.0001).

Revision of UKR to TKR is not a universally straightforward procedure, carrying significant overall cost implications. Clinical outcomes, although significantly different at 1 year are almost the same at 5 years.

Unicompartmental knee replacement (UKR) is an established treatment for single compartment end-stage knee arthrosis with good recorded survivorship. Although often used in more active, younger patients, patient selection remains controversial. To identify risk factors for early failure we compared patients with UKR failure requiring revision to total knee replacement (TKR) with a control group.

Between September 2002 and 2008, 812 Oxford Mobile Bearing Medial UKRs were implanted. 21 implants (20 patients) required revision to TKR within 5 years. The leading cause for revision was lateral compartment disease progression (11 patients). In the revision group, 17 patients were female (81%), average age at index surgery was 64.1 (range 48–81) and average BMI 31.8 (range 24.4–41.5).

Our UKR patients with early failure requiring revision were more likely to be female (p=0.0012) whilst age and BMI were similar between groups. Although the change in tibio-femoral valgus angle was similar, control group patients started in varus becoming valgus post-operatively, whereas revision group patients started in valgus and became more valgus post-operatively. This might explain lateral compartment disease progression as our leading cause of early failure. We believe females with medial compartment disease but valgus alignment are at greater risk of early failure and it is particularly important not to overstuff the medial compartment.

The Femoro Patella Vialli (FPV) is indicated for isolated patello-femoral joint replacement (PFJR). It is now the second most commonly used PFJR in the UK, however there are limited studies evaluating its outcome. Key differences include a larger component sulcus angle of 140 degrees which more closely mimics the normal knee.

Between 2006 and 2012, we performed 53 consecutive FPV patellofemoral arthroplasties in 41 patients with isolated patellofemoral joint osteoarthritis. Mean age was 62.2years (39–86) and mean follow-up was 3.5 years. Mean Oxford Knee scores improved from 19.7 to 37.7 at latest follow-up. Ninety four percent of patients were happy or very happy with their knees. Progression of tibiofemoral osteoarthritis was seen 12% of knees. 2 knees required revision to TKR at 7 months post-operatively, which we attribute to poor patient selection. There were no cases of maltracking patella or patella dislocations at final follow-up, which we attribute to the larger sulcus angle. There were no cases of radiological loosening.

Our findings suggest the FPV patellofemoral prosthesis has good mid-term functional outcomes.

A simple classification system, NOF complexity classification, was developed at the Great Western Hospital Trauma and Orthopaedic department, allowing stratification of resources. This is a four-group classification system, each group with two elements, firstly the patients medical fitness and secondly the complexity of the fracture. (C0=medically fit + simple fracture, C1=medically fit + complex fracture, C2=medically unfit + simple fracture, C3=medically unfit + complex fracture)

Between June 2008 and June 2009, data was collected retrospectively for 290 patients during a weekly MDT meeting to enter data that has been gathered into a departmental database to monitor our performance. The outcomes that we looked for to test the validity of this classification are the thirty-day mortality, annual mortality and length of hospital stay all stratified by complexity.

Results showed that there has been a strong correlation between the complexity classification and the 30-day and annual mortality with P values of 0.015 and 0.008 respectively. This resulted in a 30-day mortality of 4.4%, which is half the national average. Our average length of stay was equal to the national average of 23 days.

This classification system has allowed an improvement in service by adapting a classification system, which is understood by both the Orthogeriatric and Orthopaedic teams.

Orthopaedic practice is increasingly guided by conclusions drawn from analysis of Joint Registry Data. Analysis of the England and Wales National Joint Registry (NJR) led Sibanda et al to conclude that UKR should be reserved for more elderly patients due to higher revision rates in younger patients. To determine our UKR revision rates at the Great Western Hospital we requested knee arthroplasty data from the NJR, Hospital Episode Statistics (HES) data submitted by our centre to the Primary Care Trust, and interrogated our internal theatre implant database. This revealed significant discrepancies between different data sources.

We collected data from each source for 2005, 2006, and 2007. Operations were classified as TKR, UKR, Other or Unspecified. Results are illustrated in the attached table:

Key findings:

Our theatre implant database appears most accurate and includes a greater number of joint replacement operations than NJR or HES data and fewer ‘unspecified’ procedures.

In summary there is significant inaccuracy in our NJR data which may affect the validity of conclusions drawn from NJR data analysis. HES data is even less accurate with implications for hospital funding. We strongly advise other centres to continue to maintain accurate implant data and to perform a similar audit to calculate error rates for NJR and HES data. Further analysis is required to identify at which stage of data collection inaccuracies occur so that solutions can be devised. We are currently analysing data from 2008 and 2009.

Aim

Grade is the most important predictor of the biological behaviour of soft tissue sarcomas. Assigning a pathologic grade is always a difficult task as discordance rate is 30-40% even among experienced sarcoma pathologists. Many of these tumours are heterogeneously large and only small fractions are sampled for biopsy. This emphasizes the need for an objective and accurate assessment of histology. Our aim is to evaluate the role of Choline as a tumour marker in (i) differentiating benign from malignant soft tissue tumour, (ii) to distinguish recurrent/residual tumours using in-vivo MR spectroscopy.

Aim

Grade is the most important predictor of the biological behaviour of soft tissue sarcomas. Assigning a pathologic grade is always a difficult task as discordance rate is 30-40% even among experienced sarcoma pathologists. Many of these tumours are heterogeneously large and only small fractions are sampled for biopsy. This emphasizes the need for an objective and accurate assessment of histology. Our aim is to evaluate the role of Choline as a tumour marker in (i) differentiating benign from malignant soft tissue tumour, (ii) to distinguish recurrent/residual tumours using in-vivo MR spectroscopy.

Unicompartmental knee replacement (UKR) is an established treatment for single compartment end-stage arthrosis with good recorded survivorship. UKRs are often implanted into more active younger patients, but patient selection remains controversial. A recent study, led by the Royal College of Surgeons Clinical Effectiveness Unit, demonstrated that prosthesis revision rates decrease strongly with age (Van Der Meulen et al 2008). It has therefore been suggested that UKR should only be considered in elderly patients. This contrasts our observed experience of early revision cases leading us to compare these patients with a control group.

Between September 2002 and 2008, 812 Oxford Mobile Bearing Medial UKRs were implanted. We compared all patients who underwent UKR revision to Total Knee Replacement (TKR) against a control group of 50 consecutive UKR patients.

20 implants have required revision to TKR in 19 patients since 2002. Median age at index surgery was 68 (range 48-81), median BMI was 31 (range 25-41.5), 17 patients were female (85%), and median implant survival was 25 months (range 6-57). Control group median age at index surgery was 66 (range 46-81), median BMI was 30 (range 22-51), and 27 patients were female (54%). Median Oxford Knee Score recorded in September 2009 was 36 (range 14-54) for revision patients and 21 (range 14-39) for the control group (p=0.021).

Our UKR patients with early failure requiring revision are far more likely to be female (p=0.015), as well as older and with a higher BMI than the control group. We feel this is a subset of patients at high risk of failure, despite meeting all criteria for UKR. The underlying causes are likely to be multifactorial, but a key factor may be that this group has varus tricompartment osteoarthritis rather than classical anteromedial osteoarthritis. Our data counters recent advice based on National Joint Registry data.

The Oxford mobile bearing unicompartmental knee replacement (UKR) is a validated, highly successful implant with an excellent ten-year survivorship. From November 2001 to September 2006 three hundred and eighty two patients who had a medial cemented Oxford Unicompartmental knee replacement (Biomet, Bridgend, UK) via a minimally invasive approach were prospectively entered into a database and followed up as per departmental policy in the specialist joint assessment clinic. We have noted a minority of patients have persistent postoperative pain and/or mechanical symptoms resistant to the standard postoperative therapies. We report the outcome of 22 patients who had an arthroscopy for persistent pain and/or mechanical symptoms a median of 15 months (range 4 months – 31 months) following medial unicompartmental knee replacement. The median follow up time following arthroplasty was 38 months (range 16 months – 63 months). Post arthroscopy we divided our study patients into two groups; those who had an improvement in symptoms and those who had none. These groups were then compared, with particular reference to demographics, check radiographs and arthroscopic findings. The results showed that patients with anterior or anteromedial symptoms in whom a medial rim of scar tissue was identified and debrided sixty seven percent had a significantly increased probability of symptomatic improvement (p<0.005). In addition men appeared to significantly improve more that women (p<0.043). When performed this therapeutic intervention many prevent or at least defer the need for early revision to total knee replacement in some cases and we have no complications as a result of the arthroscopic intervention. This observational study provides evidence for a role for arthroscopy in selected patients with pain following unicompartmental knee replacement.

Background

A retrospective review of all patients transferred by helicopter ambulance to the Great Western Hospital over a 20-month period between January 2003 and September 2004 was undertaken to establish the case-mix of patients (trauma and non-trauma) transferred and the outcome of their admission and length of hospital stay.

Aim

To assess the efficacy and ease of use of the Oxford Knee Score (OKS) in soft tissue knee pathology.

Aims

To devise a simple clinical risk classification system for patients undergoing primary total knee arthroplasty (PTKR) to facilitate risk and cost estimation, and aid pre-operative planning.

Background

Referral to centres with a pelvic service is standard practice for the management of displaced acetabular fractures.

Acoustic emission is an uncommon but well-recognised phenomenon following total-hip arthroplasty using hard-on-hard bearing surfaces. The incidence of squeak has been reported between 1% – 10%. The squeak can be problematic enough to warrant revision surgery. Several theories have been proposed, but the cause of squeak remains unknown. Acoustic analysis shows squeak results from forced vibrations that may come from movement between the liner and shell. A potential cause for this movement is deformation of the shell during insertion.

6 cadaver hemipelvises were prepared to accept ace-tabular components. A shell was selected and pre-insertion the inner shape was measured using a profilometer. The shell was implanted and re-measured. 2x screws were then placed and the shells re-measured. The results were assessed for deformation.

Deformation of the shells occurred in 5 of the 6 hemi-pelvises following insertion. The hemipelvis of the non-deformed shell fractured during insertion. Following screw insertion no further shell deformation occurred.

The deformation was beyond the acceptable standards of a morse taper which may allow movement between components, and this may produce an acoustic emission. Further in-vitro testing is being conducted to see whether shell deformation allows movement producing an acoustic emission.