Introduction

We investigated whether blood metal ions could effectively identify bilateral metal-on-metal hip patients at risk of adverse reactions to metal debris (ARMD).

Blood metal ion sampling can help detect poorly functioning metal-on-metal hip arthroplasties (MoMHA's) requiring revision. Little is known about the variation in these levels following bearing exchange. This study aimed to determine the changes that occur in blood and urine metal ion concentrations following MoMHA revision.

A single-centre prospective cohort study was undertaken between 2005 and 2012 of patients with failing large-diameter MoMHA's and high blood metal ions requiring revision to non-metal-on-metal articulations. All patients had normal renal function. Whole blood and urine were collected for metal ion analysis preoperatively and regularly following revision.

Twenty-three MoMHAs (21 hip resurfacings and 2 total hip arthroplasties; mean age 56.0 years and 65% female) were revised at a mean time of 7.9 years (range 2.0–14.5 years) from primary surgery. All revisions were performed by the senior author using primary total hip implants (12 ceramic-on-polyethylene bearings, 10 oxinium-on-polyethylene bearings, and 1 metal-on-polyethylene bearing implanted). Mean (range) metal ion concentrations pre-revision were: blood cobalt 13.9µg/l (1.32–74.7µg/l), blood chromium 8.9µg/l (1.29–57.3µg/l), urine cobalt 104.6µg/24 hours (4.35–747.3µg/24 hours), urine chromium 33.2µg/24 hours (4.39–235.4µg/24 hours). After revision the mean metal ion concentrations (percentage of pre-revision values) were: blood cobalt at 2 days=10.7µg/l (77%), 6 days=7.7µg/l (55%), 2 months=3.4µg/l (24%), 1 year=1.0µg/l (7%), 2 years=0.42µg/l (3%); blood chromium at 2 days=8.7µg/l (98%), 6 days=5.5µg/l (62%), 2 months=2.2µg/l (25%), 1 year=1.5µg/l (16%), 2 years=0.97µg/l (11%); urine cobalt at 2 days=31.9µg/24 hours (30%), 6 days=21.5µg/24 hours (21%), 2 months=6.1µg/24 hours (6%), 1 year=0.99µg/24 hours (1%), 2 years=0.61µg/24 hours (1%); urine chromium at 2 days=34.4µg/24 hours (103%), 6 days=15.8µg/24 hours (48%), 2 months=9.3µg/24 hours (28%), 1 year=2.8µg/24 hours (8%), 2 years=1.9µg/24 hours (6%).

Following MoM revision cobalt levels decline rapidly in an exponential pattern with a single rate of decay through the 2 year period, reaching reference levels within the first year. Chromium follows a similar pattern but starts lower and takes longer. Renal response to cobalt returns to reference level within days of revision.

High short-term failure rates have been observed with a number of metal-on-metal (MoM) hip designs. Most patients require follow-up with blood metal ions, whichprovide a surrogate marker of in-vivo bearing wear. Given these results are used in clinical decision making it is important values obtained within and between laboratories are reproducible.

To assess the intra-laboratory and inter-laboratory variability of blood metal ion concentrations analysed by four accredited laboratories.

Whole blood was taken from two participants in this prospective study. The study specimen was obtained from a 42 year-old female with ceramic-on-ceramic hip arthroplasty failure resulting in unintended metal-on-ceramic wear and excessively high systemic metal ion levels. The control specimen was from a 52 year-old healthy male with no metal exposure. The two specimens were serially diluted to produce a total of 25 samples with different metal ion concentrations in two different anticoagulants each. Thus 50 samples were sent blinded in duplicate (total 100) to four accredited laboratories (A, B, C, D) to independently analyse blood metal ion concentrations. Ten commercially available reference specimens spiked with different amounts of metal ions were also obtained with known blood metal ion concentrations (range for cobalt 0.15µg/l-11.30µg/l and chromium 0.80µg/l to 37.00µg/l) and analysed by the four laboratories.

The intra-laboratory coefficients of variation for repeat analysis of identical patient specimens were 7.32% (laboratory A), 4.64% (B), 7.50% (C), and 20.0% (D). The inter-laboratory variability for the analysis of all 25 samples was substantial. For the unmixed study specimen the laboratory results ranged from a cobalt of 263.7µg/l (D) to 525.1µg/l (D) and a chromium of 13.3µg/l (D) to 36.9µg/l (A). For the unmixed control specimen the laboratory results ranged from a cobalt of 0.13µg/l (B) to 0.77µg/l (D) and a chromium of 0.13µg/l (D) to 7.1µg/l (A). For one of the mixed specimens the laboratory results ranged from a cobalt of 12.50µg/l (A) to 20.47µg/l (D) and a chromium of 0.73µg/l (D) to 5.60µg/l (A). Similar inter-laboratory variation was observed for the other mixed samples. The true mean (standard deviation) of the 10 commercial samples was 4.48µg/l (4.20) for cobalt and 8.97µg/l (10.98) for chromium. This was similar to the values obtained by all four laboratories: mean (standard deviation) cobalt ranged from 3.54µg/l (3.17) in laboratory A to 4.35µg/l (4.13) in laboratory D, and chromium ranged from 7.76µg/l (9.50) in laboratory B to 9.55µg/l (9.16) in laboratory A.

When testing patient samples, large variations existed both between and within four laboratories accredited to perform analysis of blood metal ion concentrations. However, this was not the case when assessing commercially spiked samples which are regularly used to validate laboratory testing. This is of great clinical concern and could lead clinicians to either recommend unnecessary revision or delay surgery, with both having the potential to adversely affect patient outcomes. It is recommended that laboratories use patient samples to assess the accuracy and reproducibility of the analyses performed. This may also assist in explaining the variations observed in this study.

Introduction

Little is known about variations in blood metal ions following bearing exchange for poorly functioning metal-on-metal hip replacements (MoMHRs). This study aimed to determine the changes that occur in blood and urine metal ion concentrations following MoMHR revision.

Aim:

AIS causes a loss of trunk height. This paper documents this loss against sitting height standards and assesses formulae for adjusting height loss back to the standard.

Oxford hip and knee scores are being used by many heath care commissioners to determine whether individual patients are eligible for joint replacement surgery. Oxford scores were not designed for use in deciding whether patients are suitable for surgery and they are not validated as a triage tool. The aim of this study was to assess what effect these predetermined threshold Oxford Scores would have on a contemporary patient cohort.

An analysis was undertaken of 4254 pre-operative Oxford scores in patients who had already undergone either hip resurfacing, a total hip, total knee or unicompartmental knee replacement surgery at our institution between 2008 and 2011. We assessed how these scores would affect the decision making pathway determining which patients would be eligible for joint replacement surgery. We also evaluated the effects this would have on patients undergoing surgery in terms of gender, sex, age and type of arthroplasty.

22.4% hip resurfacings, 10.0% of total hip replacements, 7.5% total knee replacements and 11.0% unicompartmental knee replacements would have been declined on the Oxford Scores system. The selection criteria as set by the health care commissioners was found to be ageist as there was a bias against older patients obtaining surgery. There was a bias against different forms of arthroplasty, particularly those patients suitable for resurfacing or unicompartmental knee replacement. It was also sexist as it selectively excluded male patients from surgery.

Rather than using pre-operative Oxford scores to discern which patients are eligible for surgery, evaluation of patient factors which are reported to adversely affect the outcome of hip and knee replacement surgery, may offer a better solution to improving quality of care. Oxford scores are undertaken to benchmark a providers performance and not to decide on an individual's suitability for surgery.

Background

Unicompartmental knee arthroplasty provides a good alternative to total knee arthroplasty in patients with isolated medial compartment osteoarthritis. There has been variable reporting in the literature as to whether age and sex affect the survival of unicompartmental knee arthroplasty. The aim of this study was to determine whether age and sex were predictors of failure for the Oxford unicompartmental knee arthroplasty.

Introduction

Direct lateral approaches to the hip require detachment and repair of the anterior part of the gluteus medius and minimus tendon attachments. Limping may occur postoperatively due to nerve injury or failure of muscle re-attachment. The aim of this study was to assess the integrity of abductor muscle repairs using a braided wire suture marker.

Background

A number of studies have reported on the early failure of the Oxford unicompartmental knee arthroplasty. However, less evidence is available regarding the outcome following revision of failed unicompartmental knee prostheses to total knee arthroplasty. The aims of this study were to determine the time to failure for the Oxford unicompartmental knee arthroplasty and to assess the short-term outcome following revision surgery.

Aims

The purpose of our study was three fold; firstly to assess the survival of closing wedge high tibial osteotomies (CWHTO), secondly to assess any clinical factors or radiological alignment which may affect survival and thirdly to assess the change in tibial inclination and patella height.

Aims

The primary aim of this study was to determine the long-term survival of OATS (Osteochondral Autograft Transfer System) (Arthrex, Florida, USA) grafting in our centre and evaluate the reasons for failure, the secondary aim was to ascertain if age, gender, BMI, site or size of OATS graft had any influence on outcome.

Background

Unicompartmental knee arthroplasty provides a good alternative to total knee arthroplasty in patients with isolated medial compartment osteoarthritis. There has been variable reporting in the literature as to whether age and sex affect the survival of unicompartmental knee arthroplasty.

Background

A number of studies have reported on the early failure of the Oxford unicompartmental knee arthroplasty. However, less evidence is available regarding the outcome following revision of failed unicompartmental knee prostheses to total knee arthroplasty.

Introduction

Monitoring of scoliosis is traditionally done with radiographs, which can be associated with an increased risk of cancer secondary to multiple exposures over many years. This study investigated whether the findings from surface topography can be used to monitor scoliosis curves and how much this method affects outcome scores in patients with scoliosis. This study therefore had two subsets: (1) to investigate whether lateral asymmetry (LA) from ISIS2 surface topography can predict radiographic Cobb angle, providing an alternative non-invasive means of monitoring patients with scoliosis (LA and Cobb subset); and (2) to establish the relationships between the magnitude of the deformity in scoliosis, measured by Cobb angle on radiograph and volumetric asymmetry (VA) with the ISIS2 surface topography, and the patient perception of self-image and mental health, measured with SRS-22 scores (Cobb, VA, and SRS subset).

Purpose of the study

To establish the relation between the magnitude of the deformity in scoliosis, measured by cobb angle on radiograph & Volumetric asymmetry with the ISIS2 surface topography, and the patient perception of self image and mental health, measured with SRS-22 scores.

Purpose of the study

Monitoring of scoliosis is traditionally done with radiographs which can be associated with an increased risk of cancer secondary to multiple exposures over many years. This study investigates whether lateral asymmetry (LA) from ISIS2 surface topography can predict radiographic cobb angle, to provide an alternative non- invasive means of monitoring scoliosis patients.

Aim

To assess the survival of revision knee replacements at our institution and to identify prognostic factors that predict failure in revision knee surgery.

We prospectively reviewed 2440 Cemented Anantomical (side specific) AGC total knee replacements performed on 2074 patients between 2002 and 2008 in our unit. The surgery was performed by a number of surgeons, both Consultant and Trainee grades. 1357 underwent PCL sacrificing surgery with implantation of Posterior Stabilised Femoral Implant (Cam and Grove) and 1083 underwent PCL retaining surgery with implantation of a Non-Stabilised Femoral Implant. The mean age at date of surgery for Posterior Stabilised prosthesis was 69 years (range 23-94) and Non-Posterior Stabilised prosthesis was 70 (range 33-97) with no significant difference p< 0.05 (C.I 95%). Follow up at present mean 4 years (range 1-6 years).

11 patients underwent secondary patella resurfaced for anterior knee pain at a mean of 1.5 years following the index procedure (range 0.5-4.1 years) with 6 patients reporting a marked improvement in anterior knee pain post operatively. 3 patients underwent removal of patella buttons for symptomatic loosening at a mean of 2.7 years follow index procedure.

A total of 17 patients underwent a revision of either tibial or femoral components (0.7%). Indications for revision were infection in 11 patients, gross instability in 1 patient, periprosthetic fracture in 1 patient, persistent stiffness in 1 patient. 3 patients underwent revision for symptomatic loosening of the tibial component at a mean of 2.9 years (range 1.1-4.0).

These short to medium term results for the Anatomic AGC total knee replacement agree with published results from other centres.

Introduction

Secondary osteoarthritis in a dysplastic hip is a surgical challenge. Severe leg length discrepancies and torsional deformities add to the problem of inadequate bony support available for the socket. Furthermore, many of these patients are young and wish to remain active, thereby jeopardising the long-term survival of any arthroplasty device.

For such severely dysplastic hips, the Birmingham Hip Resurfacing (BHR) device provides the option of a dysplasia component, a hydroxyapatite-coated porous uncemented socket with two lugs to engage neutralisation screws for supplementary fixation into the solid bone of the ilium more medially. The gap between the superolateral surface of the socket component and the false acetabulum is filled with impacted bone graft.

Introduction: The Oxford hip score (OHS) instrument is used to assess pain and disability before and after hip arthroplasty and may be used as a standard for auditing pre and post-operative patients. It has been suggested that patients with a low pre-operative hip score (< 25th percentile) should be carefully assessed before surgical management is employed. This study aimed to determine the factors that influence a surgeon’s decision to undertake hip arthroplasty in patients with a low pre-operative hip score.

Methods: All patients who underwent hip arthroplasty over a two month period (n=121) were included. Of these, four pre-operative OHS questionnaires were missing. The remaining (117) were validated and those scoring below the published 25th percentile (58.3%) were selected (n=35), termed the ‘low-group’. Individual OHS responses scored 0–4 were examined (0 = no impairment and 4 = worst impairment) and the proportional differences between the responses for this group and the remaining 75% were investigated. The pre-operative radiographic Tönnis stage of osteoarthritis was determined.

Results: The median cohort OHS was 68.8% (IQR = 50–79%). Of the questions that scored highly, 59% were purely pain related, 14% function and 27% both. 66% of patients experienced moderate/severe pain and 31% suffered night pain. The ‘low-group’ never scored 4 (worst impairment) on questions concerning washing, transport, shopping, stairs and work. However, 57% scored 4 on questions encompassing a pain component. In all questions except donning socks and walking, the proportion of 4 in the ‘low-group’ was significantly different to the remainder of the cohort. Tönnis grade 3 (osteophytes and advanced loss of joint space) osteoarthritis predominated (49%).

Conclusion: Arthroplasty in patients with low pre-operative OHS is influenced mainly by pain affecting quality of life. Half of these patients also have advanced features of osteoarthritis on radiographic assessment despite the low scores.

Introduction: A proposed benefit of hip resurfacing is straightforward revision. This study assesses the outcome of revision in a large series of failed resurfacings.

Methods: A consecutive series of 84 revisions of metal-on-metal hip resurfacings was analysed. The cohort consisted of 51 (61%) women and 33 (39%) men with a mean age of 48.0 years (range: 15.1–75.3 years) at primary resurfacing. The underlying diagnosis was primary osteoarthritis in 40 (48%) patients, developmental dysplasia of the hip in 13 (15%), avascular necrosis in 9 (11%) and slipped upper femoral epiphysis in 7 (8%).

Mean patient age at first revision was 50.8 years (range: 18.4–75.9 years), at a median of 1.8 years (25^th percentile 0.03 years, 75^th percentile 4.6 years) after the primary operation. 29 (35%) resurfacings were revised for aseptic loosening, 23 (27%) for periprosthetic fracture, 8 (10%) for component malalignment, 8 (10%) for pain alone, 4 (5%) for infection, 4 (5%) for avascular necrosis and 4 (5%) for instability.

Results: At a mean follow-up of 4.6 years (range: 1.0–8.2 years) after the first revision, 10 (12%) of the revised hips had undergone a second revision procedure. 6 men and 3 women required re-revision (data not available for 1 patient). The reasons for the first revision were acetabular malalignment (n=2), femoral neck fracture (n=2), aseptic loosening (n=2), avascular necrosis (n=1), instability (n=1) and pain alone (n=1). The second revision was required at a mean of 3.4 years (range: 0.4–6.3 years) after the first.

Discussion: This study suggests that revisions of hip resurfacing for acetabular malalignment may be at increased risk of subsequent re-revision (2 of 7 patients, 29%). Revision for other causes appears to have better survival in the short to medium term.

Introduction: In contrast to degenerative (OA) and inflammatory arthritides which are primarily joint surface diseases, femoral head osteonecrosis (ON) is a bone substance disease which extends to the surface. Is HR effective in ON?

Methods: This is a single-surgeon retrospective consecutive case-series with a 5 to 15-year (mean 9.5) follow-up of 95 patients (104 hips) with Ficat-Arlet III/IV ON treated with HR. Mean age is 43 (18 – 68) years. Two patients died from unrelated causes and none is lost to follow-up. Revision of either component for any reason was the end-point. Patients were assessed clinically and with hip function scores and anteroposterior, cross-table lateral radiographs.

Results: Ten failures (1 fracture, 6 femoral head collapse, 2 infections, 1 cup loosening) give a failure rate of 9.6% and 89% survivorship. All the above have been converted to total hip arthroplasty (THA). In one further patient the femoral component has tilted into varus. No other patient shows clinical or radiological adverse signs.

Discussion and Conclusion: Several studies in THA suggest that the results are generally worse in patients with ON compared to those with OA. Others find no difference. Our results show that the cumulative survival of HR in osteonecrosis is worse than that with other diagnoses. Further collapse of the femoral head is the most common reason for failure and it occurred between 3 and 9 years after implantation. HR was originally an option for hip joint surface disease such as OA. ON being a substance problem is in our hands a relative contraindication to hip resurfacing.

Introduction: Metal ion release from metal-metal (MM) joints continues to cause concern. Blood metal levels are a measure of systemic exposure. The usefulness of plasma and erythrocyte levels rests on whether individual variability in these blood fractions is within acceptable limits.

Methods: 461 concurrent specimens of whole blood (WB), plasma and erythrocytes from a heterogeneous group of patients with large and small diameter MM hip arthroplasties were analysed using high resolution mass-spectrometry. 41 specimens were excluded because the level was below the limit of detection. Agreement was assessed with scatter plots, mean differences and Bland and Altman limits of agreement. A p value of d0.05 was considered significant.

Results: Mean differences between WB and its fractions were statistically highly significant (p< 0.001). The scatter showed that the variability in plasma chromium was worse at lower levels and that in erythrocytes was worse at higher levels. Bland analyses showed the limits of agreement extended from −106% to 74% for cobalt and −108 to 158% for chromium and −58% to 46% for cobalt and −63% to 52% for chromium in erythrocytes and plasma respectively. Erythrocyte chromium distribution in the erythrocytes shows no increase with increasing chromium levels in WB.

Discussion: and Conclusion: The variability with plasma and erythrocytes compared to WB metal ion levels rejects the hypothesis that these can be used as surrogate measures of systemic exposure. There appears to be a cellular ceiling beyond which chromium entry into the cell is resisted. This makes erythrocyte levels particularly unsuitable as markers of systemic chromium exposure.

We report the survival at ten years of 173 consecutive Birmingham Hip Resurfacing’s implanted between August 1997 and August 1998 at a single institution. Failure was defined as revision of either the acetabular or femoral component for any reason during the study period.

The survival at the end of ten years was 96.5% (95%c. i. 89.1 – 99.5%) The mean age of the patients at implantation was 50 years (range 15 – 75). There were 124 (72%) male cases and 49 (28%) female cases. 123 (71%) cases had the diagnosis of osteoarthritis, 9 osteonecrosis, 5 rheumatoid and 3 DDH. The posterior approach was used in 154 (89%) cases and anterolateral in 19 (11%). Cases were performed by 5 different surgeons.

There were 5 revisions, 9 unrelated deaths and 18 were lost to follow-up beyond 5 years. Two revisions occurred for infection (6 months and 2 years). A revision at 3.5 years for acetabular loosening and two further at 6.4 and 7.9 years due to avascular necrosis of the femoral head and collapse were performed. No other revisions are impending. The median pre-operative oxford hip score was 61% (IQR 48–73) and the median 10 year score was 7% (IQR 0–31) for 110 completed forms.

Further analysis of the total resurfacing database at this institution of 2775 cases was performed. Cox-proportional hazard analysis identified that component size and pre-operative diagnosis were significantly associated with failure. Although females may initially appear to have a greater risk of revision this is related to differences in the size and pre-operative diagnosis between the genders. This study confirms that hip resurfacing using a metal-on-metal bearing of known provenance can provide a solution in the medium term for the younger more active adult who requires surgical intervention for hip disease.

Introduction: Metal-metal (MM) surface replacement arthroplasty of the hip is showing promise as an effective and enduring solution in the management of hip arthritis in the young, and is being increasingly used. The main concern is the release of metal ions into the systemic circulation and their long-term effects. There is concern that metal ions cross the placenta in pregnant women with MM bearing arthroplasties with the potential for mutagenic effects in the offspring. The hypothesis is that metal ions pass freely through the placenta and that there is no difference in the maternal and cord metal ion levels.

Methods: This is a controlled cross-sectional study of women of child-bearing age with MM bearing surface replacement arthroplasties. (n= 25, mean age: 32 years, mean duration after resurfacing 60.3 months, 3 bilateral). The control group consisted of 24 subjects who do not have a metallic implant, were not taking any supplements containing cobalt or chromium salts and were registered to undergo an elective LSCS at the regional hospital. Mean age of the control group was 31.3 years. No patient in either group was known to have renal failure. Whole blood specimens were obtained from the mothers just before delivery and before infusion of any fluids, and cord blood specimens were obtained immediately after delivery. High resolution inductively couples mass spectrometry (HRICPMS) was used for metal ion analysis.

Results: Cobalt and chromium were detectable in all specimens in both the study patients and controls. In the study group, mean cord metal ion levels were significantly lower than the maternal cobalt (p < 0.05) and chromium (p < 0.0001) levels thus rejecting the null hypothesis. In the control group, the mean difference between maternal and cord metal ion levels was only 5 to 7% and was statistically not significant (p > 0.5).

The mean difference in cord chromium between the study and control groups is not statistically significant (p > 0.05), although cord cobalt in the study group is significantly higher (p < 0.01) than that in controls. Whilst there is a four-fold elevation of maternal cobalt in the study patients and an almost 7-fold increase in maternal chromium levels as compared to the control group, the elevation in the cord cobalt and chromium in the study group are smaller.

Discussion and Conclusion: The differences between maternal and cord metal ions in the control patients indicate that normally the placenta allows an almost free passage of metal ions. This is understandable when we realize that these elements are also required by the developing foetus for its cellular and metabolic functions. The relative levels of metal ions in the maternal and cord blood in the study group patients reveal that the placenta does exert a modulatory effect on metal transfer. The mean cord levels of cobalt and chromium in these patients are only 57% and 24% of the maternal blood levels respectively. There is a continuing need for efforts to reduce metal ion release from artificial joints and also to monitor metal ion levels in patients with MM devices.

Introduction: The senior author undertakes single stage revision hip arthroplasty for cases with no preoperative evidence of infection based on history and examination, ESR and CRP results and negative results from selective aspirations. Despite this a large proportion of intra-operative samples are positive for infection. The purpose of our study is to look at the results of intra-operative histology and microbiology samples in these cases and to assess the subsequent incidence of infection.

Methods: Retrospective case study comprising of 230 single stage revision total hip arthroplasties carried out by a single surgeon over 5 year period (2003–2008). Intra-operatively tissue samples were taken from multiple sites and sent for both histology and microbiology. Microbiology results were reported at 24hrs, 48hrs, 7 days and 21 days and correlated with histology reports.

Results: From a total number of 230 patients, we had 98 left and 132 right hip revision arthroplasties. There were 95 men and 135 women with a mean age of 73 years (range 40–93). Intra-operative microbiology was negative in 108 patients (46.95%), of which 3 patients’ histology samples were consistent with infection. Of the 122 microbiology positive patients (53.04%), there were 8 histology samples consistent with infection. The most frequent growths were of Coagulase negative Staphylococcus (64 cases) and Propionibacterium (18 cases). 3 cases subsequently developed deep infection.

Discussion: This study highlights a significant discrepancy between intra-operative microbiology and intra-operative histology results. There is also a very high discrepancy between pre-operative assessment and intra-operative microbiological findings although the majority of cases subsequently did not show any clinical evidence of infection.

Introduction: The Corail stem is a well proven femoral implant used for the past 22 years. It is the most common uncemented femoral stem used for total hip replacements in the UK. The stem was modified in 2004 with an increased neck taper to allow for an increased range of bearings and modular heads. This study reviews a series of primary total hip replacements using this recently modified Corail stem to assess if this implant is still performing to acceptable standards.

Method: A prospective patient database collated by 2 arthroplasty surgeons recorded data at the time of operation and subsequent follow up. All intra-operative and post-operative complications were recorded. Pre and postoperative oxford hip scores were analysed.

Results: 751 cases were reviewed. The average age was 63 with females accounting for 69%. The pinnacle cup was used in 83% of cases, with a polyethylene bearing in 48%. Survival of the stem at 3 years was 99.9% (1 periprosthetic fracture following a fall), the cup 99.6%, with overall survival of 99.5%. The most common intra operative complication was calcar fracture occurring in 0.9%. Dislocation occurred in 0.5%, subsidence in 0.3%, deep infection in 0.1% and leg length discrepancy requiring shoe raise in 0.1%. Average 3 year oxford hip score was 12.

Discussion: 3 year survival of both the femoral stem and the total hip replacement are above the quoted rates in the National Joint Registry’s 4th annual report for corail and uncemented stems (98.8% and 98.1% respectively), and also exceeds that of cemented stems (99.1%). The same report quotes similar rates of calcar fractures (0.8%), although we recorded no other perioperative complications. We conclude the new generation of Corail stem has excellent 3 year performance.

Introduction: Hip resurfacing has gained popularity for treating young and active patients with arthritis. Recent literature has reported increase revision rate amongst females as compared to males undergoing resurfacing. The aim of this study is to identify any differences in survival or functional outcome between male and female patients treated with metal-on-metal hip resurfacing.

Methods: All procedures performed between July 1997 to July 2003 were extracted from the database and grouped based on gender. 1266 patients (1441 hips, 582 female and 859 male patients) were identified. The preoperative diagnosis, Oxford hip score, component size, post operative complications and revisions were recorded. Failures included revision of either the femoral or acetabular components.

Results: The mean follow up was 5.5 years. There were 52 revisions in total (30 in female and 22 in male group). The 8 year survival in the male and female groups were 96.1% and 91.5% respectively which is significantly different (p=0.0006). The size of the femoral component was significantly associated with revision (p=0.0008). Cox proportional hazard modelling including gender, aetiology and femoral component size identified a diagnosis of osteoarthritis reduced the risk of revision of 0.2 times (p=0.0004). However, SUFE was significantly associated 5.57 times increased risk of revision (p=0.0019). With every millimetre increase in head size there was a reduction in risk of revision of 0.89 (p=0.0098). By inclusion of all variables in this model gender was found not to be significantly associated with failure.

Conclusion: This study demonstrates that although females may initially appear to have a greater risk of revision this is related to differences in the femoral size and pre-operative diagnosis between the genders. Patient selection for resurfacing is best made on size and diagnosis rather than gender.

Background: Scoliotic deformity has been traditionally measured by Cobb angle using radiography. This parameter gives a measure of the lateral curve in the spine in the coronal plane. However, patients are often more concerned about their rib humps or other volumetric asymmetries in the surface of their backs. There is often little relation between Cobb angle and the magnitude of the asymmetry. A method of quantifying volumetric deformity, especially if it requires no radiation, would therefore be useful for spinal surgeons and patients alike.

Methods: The three dimensional shape of the back is measured using structured light and digital photography with ISIS2, a non-commercial surface topography system. Markers are placed on bony landmarks so that the surface can be related to body axes. A zero plane is defined through the sacrum and the vertebra prominens, parallel to the line between the markers on the dimples of Venus. A curve is fitted through the markers on the spinous processes on the measured surface and is used as the line of symmetry. The difference in the areas between the surface and the zero plane on each side of the symmetry line is then calculated for each horizontal (transverse) section. The left and right volumetric asymmetry parameters are then calculated by summing the area differences on each side and normalising for back length. These parameters range from zero for a perfect straight back with no transverse asymmetry to over 70 for extreme transverse asymmetry. The variability in these parameters was investigated using pairs of photographs of 59 patients. Two photographs were taken with the patient walking around the room between them. Left and right volumetric asymmetry was then calculated for each measurement and Bland-Altman analysis was carried out.

Results: The mean difference between pairs of measurements was −0.10, the standard deviation was 2.03 and the 95% tolerance limits covering 95% of the population were −4.8 to 4.6 for left volumetric asymmetry; the mean difference was 0.46, standard deviation was 3.13 and the 95% tolerance limits covering 95% of the population were −6.8 to 7.7 for right volumetric asymmetry. There was no evidence of bias from the Bland-Altman plots.

Conclusions: The variability in the volumetric asymmetry was low in comparison to the levels found for subjectively classified ‘moderate’ deformity. Change in degree of volumetric deformity can be monitored by ISIS2 volumetric asymmetry.

Metal-on-metal hip resurfacing is increasingly common. Patients suitable for hip resurfacing are often young, more active, may be in employment and may have bilateral disease. One-stage bilateral total hip replacement has been demonstrated to be as safe as a two-stage procedure and more cost effective. The aim of this study was to compare the in-patient events, outcome and survival in patients undergoing one-stage resurfacing with a two-stage procedure less than one-year apart.

Methods. Between July 1994 and August 2006 a consecutive series of 93 patients underwent bilateral hip resurfacing within a year. 34 patients in the one-stage group. 44 patients in the two-stage group. The age, gender, diagnosis, ASA grade, total operative time, blood transfusion requirements, medical complication, surgical complications, length of stay, duration of treatment, revision and Oxford hip scores were recorded.

Results. There were no significant differences in age, gender, ASA grade between the one-stage and the two-stage. There were 4 minor complications in the one stage group and 5 in the two-stage group. All patients that suffered a complication made a full recovery. There was no significant difference in the blood transfusion requirements. The mean anaesthetic time was 136 minutes in the one stage group and 92 minutes in the two-stage group with a significant mean difference of 44 minutes(95% c.i. 31–52). The mean total length of hospital stay was 11 days in the one-stage group and 16 days in the two-stage group with a significant mean difference of 5 days(95\% c.i. 4.0–6.9). The mean difference in length of treatment time of 6.5 months was significant(95\% c.i. 4.0–9.0).

No patients have undergone a revision procedure during the study period and no patient is awaiting revision surgery.

Conclusions. This study demonstrates no detrimental effects when performing a one-stage bilateral metal-on-metal hip resurfacing in comparison to a two-stage procedure. There are advantages of a one-stage procedure over a two-stage procedure for bilateral disease. Total hospital stay is reduced by 31.3% and the mean length of treatment is reduced by 50.0%. These benefits do not appear to come at the cost of increase complications. The complication rate in both groups was very low and all of the complications were short-term and are unlikely to have any bearing on the longevity of the prosthesis.

ISIS2 is a surface topography system measuring the three-dimensional shape of the back in scoliosis patients using digital photography with structured light. Lateral asymmetry is the ISIS clinical parameter estimating the curve of the spine in the coronal plane [1]. The shape of the back changes with patient stance, breathing and muscle tension. Although ISIS2 uses bony landmark markers to minimise the effect of stance, there will still be variations from measurement to measurement. The aim of this work is to quantify the variability in lateral asymmetry measurements. The patients were asked to stand in the patient stand in a relaxed normal pose; the feet were placed just outside the blocks on the footplate, the abdomen rested lightly against the crossbar of the stand, and the arms were supported away from the sides of the body by the arm rests. Two photographs were taken with the patient walking around the room between them. The mean difference between pairs of measurements on 62 patients was 0.12°, the standard deviation was 1.64° and the 95% limits of agreement were −3.10° to 3.34°. A plot of difference against mean showed no significant evidence of a relationship between them (r = −0.10). The standard deviation for intraob-server measurement of Cobb angle has been reported as ranging from 1.4° to 3.3° [2,3,4] and clinically significant change is generally regarded as greater than 5°. This experiment shows that intraobserver variability in lateral asymmetry is thus sufficiently low to detect clinically significant changes in the curve of the spine.

An automated system has been developed to measure three-dimensional back shape in scoliosis patients using structured light. The low-cost system uses a digital camera to acquire a photograph of a patient with coloured markers on palpated bony landmarks, illuminated by a pattern of horizontal lines. A user-friendly operator interface controls the lighting and camera and leads the operator through the analysis. The system presents clinical information about the shape of the patient’s deformity on screen and as a printed report. All patient data (both photographs and clinical results) are stored in an integral database. The database can be interrogated to allow successive measurements to be plotted for monitoring the deformity.

The system is non-invasive, requiring only a digital photograph to be taken of the patient’s back. Identification of the bony landmarks allows all clinical data to be related to body axes. This reduces the effects of variability in patient stance. Measurement of a patient, including undressing, landmark marking and dressing, can be carried out in approximately 10 minutes. The clinical results presented are based on the old ISIS report. This includes:

transverse sections at 19 levels from vertebra prominens to sacrum.

Additionally, a three-dimensional wire-frame plot, a coloured contour plot and a pair of bilateral asymmetry plots give visual impressions of any deformity in the measured back.

Introduction. Painful post-collapse femoral head osteonecrosis (AVN) continues to be a therapeutic challenge. Joint preserving surgery does not produce satisfactory results after femoral head collapse, making an arthroplasty almost inevitable. Does metal-metal resurfacing offer a conservative option that matches the consistent results of a stemmed THA in these patients?

Methods. 104 consecutive resurfacings (94 patients) performed for Ficat stage III/IV AVN were reviewed clinically, radiologically and with Oxford hip scores. Mean age at operation was 43.9 years. Aetiology included trauma (20%), steroids/chemotherapy (25%), alcohol abuse (8%), AVN secondary to Perthes’/SUFE (4%) and idiopathic (43%). Two types of devices were used a) McMinn Resurfacing Arthroplasty, HA-coated smooth uncemented cup and cemented femoral component and b) Birmingham Hip Resurfacing, porous HA cup and cemented femoral component.

Results. At 2 to 11.5 years (mean 7.7 years), there were seven (6.7%) failures: four from further femoral head collapse, two infections and one osteolysis, aseptic loosening. The cumulative survival at 11years is 90% (figure 1). Mean Oxford score at follow-up is 15.4. 55% participate in moderate to heavy work or participate in regular sporting activity.

Discussion. The results of any treatment modality in AVN are not as good as those in osteoarthritis. One reason is that the etiopathological factors that caused non-traumatic AVN (steroids etc) have the potential to cause continued femoral head damage. Post-traumatic patients need complex reconstructions and risk a higher failure rate. Those on immunosuppressants are prone to infections. The results of hip resurfacing in AVN in this series are no different from THRs in many published series. Metal-metal resurfacing is a good conservative option for post-collapse femoral head AVN and gives acceptable results if strict patient selection criteria are followed.

Introduction: Hip resurfacing is a bone conserving option that offers a better revision prospect for young and active patients. Encouraging results from several centres prove that they function well in the early years. Their long-term survival will be known from continued monitoring of early resurfacings.

Methods: This is a retrospective study of two cohorts of young (< 55 years) patients of osteoarthritis treated with hybrid-fixed metal-metal resurfacings. The cohorts are a) consecutive patients treated by the senior author in 1994 and 95 with a hydroxyapatite-coated smooth uncemented cup and a cemented femoral component and b) consecutive patients treated with hydroxyapatite-coated porous uncemented cup and a cemented femoral component since 1997 with a minimum follow-up of 5 years. 420 resurfacings (360 patients, 287 males and 73 females) were reviewed with Oxford hip scores and activity level monitoring (UCLA scale). Mean age at operation was 48.3 years.

Results: Ten patients (11 hips) died from unrelated causes. Out of the remaining 409 hips (350 patients) at a follow-up of 5 to 11.5 years (mean 7.1 years), there was one failure (cumulative failure rate 0.25% at 11 years) from avascular necrosis of the femoral head. The mean Oxford score of the 350 patients is 13.4. 87% had a UCLA score of 7 and above. 55% participated in impact sports or were involved in heavy occupational work.

Discussion: In the present study, with no loss to follow-up, excellent hip survival (99.75%) and activity level were seen. Young patients regard return to activities as one of their highest priorities. None of these patients were advised to change their activities at work or leisure.

The extremely low failure rate in the medium term proves the suitability of resurfacing in young active patients. However, caution needs to be exercised until long term results are available.

Introduction: Metal ions generated from metal-metal joints are transported in plasma and within cells. Whole blood (WB) analysis is a good measure of systemic metal exposure because it includes both intracellular and extracellular compartments. Analysis of whole blood is technically more challenging than serum. But can serum levels be considered equivalent to whole blood levels in the assessment of systemic metal exposure?

Methods: 262 concurrent WB and serum specimens from patients after metal-metal hip arthroplasty were analyzed for metal levels by high-resolution mass-spectrometry (reporting limits 0.06μg/l for serum and 0.1μg/l for WB). The relationship between serum and WB levels were studied using four methods of agreement testing: paired t-test, Pearson correlation, Bland-Altman agreement and variability on normalized-scatter.

Results: Mean WB and serum chromium concentrations were 2.2 and 4.2μg/l (p< 0.001). Corresponding values for cobalt were 2.4 and 3.2 μg/l (p< 0.001). The normalized scatter (fig 1B) shows poor congruence between whole blood and serum levels especially at lower concentrations. Pearson correlation confirms poor agreement at lower concentrations even after excluding outliers.

Bland-Altman analysis (Figure 1A) shows the limits of agreement between serum and WB are unacceptably wide (1.7 to -5.1 for chromium) suggesting poor agreement.

Discussion: The proportion of metal ion levels in serum and blood cells shows great variability. With advances made inmass-spectrometry, poor instrument sensitivity is a non-issue. Is there then a case for continued use of serum as a measure of systemic metal ion exposure? It can be justified only if serum levels show good agreement with WB levels throughout the range of measurements. Concurrent analysis of serum and whole blood metal ion concentrations in the present study, do not show such an agreement with four methods of testing, suggesting that serum metal concentrations cannot be reliably used as an instrument to measure systemic metal ion exposure.

Objective: Diagnostic delay is well recognised in soft tissue sarcoma (STS). The aim of this paper is to assess whether symptom duration/time to diagnosis, has any impact on patient survival and also if patient and tumour-related factors are related to the duration of symptoms prior to presentation.

Method: We performed a retrospective analysis of prospectively collected data for all patients diagnosed or treated with STS at our centre over a 20-year period. Information regard¬ing when the patients first experienced symptoms was entered into a local oncology database at their first consultant-outpatient appointment. Symptom duration was defined as time in weeks from first symptoms experienced by the patient to the time of diagnosis. Data analysis was performed using StatView and R. Risk factors were assessed by Kaplan-Meier analysis and the Cox proportional hazards model. Stat¬istical significance was determined using 95% confidence intervals where appropriate. Students t-test was used to compare categorical data.

Results: The study population comprised 1508 patients. 159 had metastatic disease at diagnosis and overall 5-year survival in this group was 14%. In view of this poor prognosis these patients were excluded from further analyses. In the remaining 1349 patients overall 5-year survival was 60%. Mean symptom duration within our study was 70.2 weeks. A Cox Proportional hazards model showed that duration of symptoms had a significant impact on survival (p=0.0037) with each additional week of symptoms reducing the monthly hazard rate by 0.2%. Patient and tumour-related factors that were significantly associated with longer symptom durations were low grade, subcutaneous tumours, and those patients with either epitheliod or synovial sarcomas. Symptom duration was not associated with tumour size or patient age/gender.

Conclusion: Patients presenting with long symptom durations/diagnostic delay, tend to have low grade disease and a more favourable outcome than patients who experience short symp¬tom durations.

To determine the ten-year survivorship of the Original M E Muller Straight Stem Total Hip Replacement System with emphasis on the longevity of the femoral component in accordance with guidelines published by the National Institute of Clinical Excellence, 266 consecutive hip arthroplasties using the above prosthesis were performed by the senior author between 1983 and 1992. 24 patients were lost to follow-up. Of the remaining 242 patients 80 were male and 162 female. The mean age was 67.49 years. The diagnosis for the majority of patients was osteoarthritis of the hip joint. Pre-operative planning was carried out and the patients were scored using Charnley’s modification of the d’ Aubigne and Postel numerical grading system A mono-bloc stem with a 32-millimeter head used via the trans gluteal approach recommended by Muller. Following discharge serial follow-up consisted of both clinical and radiological evaluation. The data was prospectively stored on a Microsoft access database. The survival of the prosthesis using revision for aseptic loosening as an end-point was calculated by actuarial analysis.

135 patients attended their ten-year follow-up. 97% of patients had good to excellent pain relief and improvement in movement of the joint following surgery. 38% had good to excellent mobility with the remaining having restricted mobility due to associated co-morbid factors. Only in 3% of patients was mobility restricted as a result of the arthroplasty. 7 revisions were carried out for aseptic loosening, all as a result of failure of the acetabular component. The cumulative survival for this hip replacement system was 95.9% and that for the femoral component was 100% at 10 years.

The Muller Straight Stem femoral component is based on a press-fit concept and gives predictable long-term results when recommended surgical technique is followed. This series confirms the reliability of the stem design and satisfies the NICE guidelines.

Metal on metal hip resurfacing was introduced in 1992 by Derek McMinn initially using an all cementless device and then an all cemented device. A hybrid resurfacing with a cemented femoral component and a cementless acetabular component was introduced in 1994. The manufacturer of the hybrid hip resurfacing was changed in 1996. Since 1997 the Birmingham hip resurfacing has been in continuous use.

The device is approved by NICE (National Institute for Clinical Excellence) for use within the NHS in patients with Osteoarthritis of the hip. The device is not yet approved for use in patients with Rheumatoid Arthritis and other types of inflammatory arthritis. There are concerns regarding bone quality in rheumatoid patients, which may result in a high incidence of component loosening or femoral neck fracture. Conventional total hip replacement is a successful procedure in inflammatory arthritis however with modern treatments producing increased activity levels there are concerns about polyethylene wear.

The author has performed metal on metal hip resurfacing in patients with inflammatory arthritis over the past 12 years. A total of 170 patients have been operated on with 198 resurfacings. 33% of patients have a diagnosis of some type of inflammatory arthritis. The outcomes have been assessed using Oxford hip scores and long term clinical and radiological review. Our results indicate that there is a minimal risk of femoral neck fracture and a minimal risk of component loosening when the device is used with this approach in patients with inflammatory arthritis.

Hip Resurfacing has always been an attractive concept for the treatment of hip arthritis in younger patients. Introduction of modern metal-on-metal hip resurfacing in 1991 in Birmingham, UK made this concept a reality.

In the early years, resurfacings were used only by a few experienced surgeons. From 1997, Birmingham Hip Resurfacings (BHRs) are being widely used in younger and more active patients. A breakdown of the ages at operation in the regional NHS hospital in Birmingham during the period April 1999 to March 2004 show that the mean age of metal-metal resurfacings is 51 years and the mean age of total hip replacements is 70 years.

At a 3.7 to 10.8 year follow-up (mean follow-up 5.8 years), the cumulative survival rate of metal-metal resurfacing in young active patients with osteoarthritis is 99.8%. In the long term, none of these patients were constrained to change their occupational or leisure activities as a result of the procedure. The overall revision rate of BHRs in all ages and all diagnoses is also very low (19 out of 2167 [0.88%] with a maximum follow-up of 7.5 years).

Improvements in instrumentation and a minimally invasive approach developed by the senior author have made this successful device even more attractive. Although objective evidence does not support the fact that the longer approach was any more invasive than the minimal route, patient feedback shows that it is very popular with them. While minimal approach is indeed appealing, it has a steep learning curve. In the early phase of this curve, care should be taken to avoid the potential risk of suboptimal component placement which can adversely affect long-term outcome.

It is true that metal-metal bearings are associated with elevated metal ion levels. In vitro studies of BHRs show that they have a period of early run-in wear. This is not sustained in the longer term. These findings are found to hold true in vivo as well, in our studies of 24- hour cobalt output and whole blood metal ion levels. Epidemiological studies show that historic metal-metal bearings are not associated with carcinogenic effects in the long-term.

Metal ion levels in patients with BHRs are in the same range as the levels found in those with historic metal-metal total hip replacements.

This study reports the early results of Birmingham Hip Resurfacing in a group of patients less than 25 years of age. We assessed over a period of 5 years all patients who underwent hip resurfacing who were under the age of 25. Thirty-eight patients underwent 43 hip resurfacing procedures for a variety of diagnoses. This included 15 with Developmental Dysplasia of the Hip (DDH), 13 with Osteonecrosis (ON) of the femoral head, and 7 with End-stage Spastic Hip Disease (ESSHD). We assessed complications, failure and revision rates. Patients completed co-op and oxford hip scores and both clinical and radiographic assessments. At a follow-up of a maximum of 5 years the survival rate was 93% with a further 7% showing radiographic features of failure. Thirteen hips (30%) had a femoral osteotomy at the time of resurfacing allowing correction of length and rotation with no apparent increase in complications. Those who required revision were successfully converted to metal- metal total hip replacement. Our results report the first use of this type of prosthesis in a group of patients under the age of 25 and demonstrate comparable results to standard treatments at this early stage. This study supports the use of hip resurfacing as alternative to conventional treatments for this complex group of patients.

Purpose: To see if current guidelines for the early diagnosis of sarcomas can be improved.

Method: Data on 1100 patients referred to our unit with a lump suspicious of sarcoma was analyzed to try and identify clinical features more common in malignant than benign lumps. The following five items were analysed: size, history of increasing size, presence of pain, depth, age. For each of these items sensitivity, specificity, accuracy and weights of evidence were collected. ROC curves were used to identify the most sensitive cut off for continuous data.

Results: The best cut off predicting malignancy for size was 8cm and for age 53 years

The weights of evidence (WE) are logs of the likelihood ratios and can be added and a probability then calculated. e.g. a 36 yr old with a 10cm, deep, painless lump that is increasing in size scores −0.39 + 0.4 + 0.4 – 0.11 + 0.58 = 0.88. This equates to a risk of the lump being malignant of 70%.

Conclusion: This analysis shows that increase in size is the strongest predictor of malignancy/benignancy followed by age > 53 and size > 8cm. This data can help formulate strategies for earlier detection of soft tissue sarcomas.

The growing interest in the use of metal on metal bearings in the treatment of end stage hip arthritis in the young has raised the need to monitor metal ion levels in these patients. Blood levels are good indices of the safety of these devices. Total wear/corrosion over a given time period is best estimated from 12 or 24-hour urine collections. Whole blood samples of 52 patients with metal on metal hip arthroplasties were analysed for levels of chromium, cobalt and molybdenum using high-resolution induction coupled plasma mass-spectrometry. Fifteen of these were in an older age group (mean age 75.3years) and had metal on metal hip replacements performed 19–28 years before the assessment. The rest (37) were younger (mean age 52.9 years) and had hip resurfacings performed in the last 4 years. The results show higher levels of ions than those found in the normal population.

This agrees with other studies. However we found no significant difference between the levels in the older patients with THR and the younger patients with hip resurfacing. In another study, urine collections from 78 patients who had hip resurfacings in the past and are now at different postoperative durations (2, 4, 6, 8, 10, 12, 18, 24 and 36-month periods) were analysed for metal ions using the same technique. The mean levels show an increase compared to the preoperative values but this increase is not statistically significant.

The urinary excretion of cobalt in these groups have also been compared with the expected cobalt release due to corrosion in this alloy. They were found to rise above the corrosion levels only in the 8–12 month period, possibly due to “run-in” of the bearing. It can be concluded that the ion levels can be attributed mainly to corrosion and there is minimal contribution from wear.

Aims: The rate of polyethylene wear has been reported to be considerably higher with uncemented metal backed cups articulating with cemented as well as uncemented femoral components. There are many reports comparing wear between cemented all polyethylene and uncemented metal backed cups from different manufacturers, however there are no reports comparing wear of polyethylene manufactured in identical method.

Patients and methods: 361 consecutive hips between 1988 and 1995 were operated at our hospital by using either cemented all polyethylene Zimmer Flanged (ZF) or uncemented Harris-Galante (HG) acetabular component rticulated with Exeter polished tapered cemented stainless steel stem with a 26mm size head. A total of 107 hips (75 ZF and 32 HG) were excluded. A custom-made computer programme was used to assess polyethylene wear (by using the method of Livermore etal). A statistical analysis was used to find average annual wear and significance of difference in the wear of ZF cups and HG cups using student’s t-test.

Results: There were 87 male and 167 were female patients with an average age of 63.92 years (18 – 86). The average follow-up for ZF cups was 3.85 years (2.5 – 5.4). and for HG cups was 5.3 years (2.5 – 9.3). The mean annual wear rate of ZF cups was 0.127mm (SD 0.088). For HG cups the mean was 0.1388mm (SD 0.086).

Conclusion: Polyethylene ZF cups have wear characteristics similar to HG cups at a mean follow-up of 4.6 years.

Purpose: Primary bone tumours situated at the distal end of the humerus are exceptional and observed in only 1% of the cases. Reconstruction at this level is often difficult due to the wide bone resection. Choosing a massive prosthesis is an interesting method allowing correct carcinological and functional results. We report a series of ten patients who underwent reconstruction of the lower end of the humerus between 1970 and 2001 with a massive prosthesis after tumour resection.

Material and methods: This series included four men and six women, mean age 51 years (15–76). Eight patients had primary bone tumours and two had secondary bone lesions. Mean follow-up was 79 months (9–372). The custom-made constrained hinge prosthesis composed of chromium-cobalt and titanium was cemented. Regular clinical and radiological follow-up data were recorded. The Henneking score and the Toronto Extremity Survival Score (TESS) were used to assess functional outcome.

Results: Three patients underwent revision for aseptic loosening of the humeral component at 48, 56 and 366 months with problem of polyethylene insert wear for two of them. There were no infctions or local recurrences and no secondary amputations. The posterior or anterolateral approach was used for humeral resection (mean 153 mm, 63–160 mm). Postoperatively, three patients developed transient palsy (one radial and two ulnar) which regressed. Four patients died from metastasis and had a satsifactory prosthesis result at time of death. The mean TESS was 73% (29–93%) at last follow-up

Discussion: Although this is a small series, the long-term results appear to indicate that reconstruction of the lower extremity of the humerus with a massive prosthesis is a satisfactory option for this rare tumour localisation.

Between 1965 and 1973 a total of 808 McKee-Farrar metal-on-metal cemented total hip arthroplasties were performed in the Norfolk and Norwich Hospital. Of these, 230 surviving arthroplasties have been reviewed at average follow-up of 13.9 years. There were good or excellent results in 49% of the arthroplasties as judged by the Harris hip score with 78% of these having little or no pain. A comprehensive radiographic analysis was undertaken and a survivorship study of 81% of the total number of prostheses is presented.

Mechanical abnormalities of the patellofemoral joint are among the many causes that have been suggested for adolescent knee pain. This study seeks to identify these factors. Measurements of joint mobility and lower limb morphology were made on 446 pupils at a comprehensive school, 136 of whom had suffered knee pain in the previous year. The pupils with symptoms enjoyed sporting activities significantly more than their symptom-free contemporaries. Joint mobility, the Q-angle, genu valgum and anteversion of the femoral neck were not significantly different between those pupils with and those without anterior knee pain. Data on lower limb morphology of normal adolescents are presented. Examination of 52 hospital outpatients aged 13 to 36 years with anterior knee pain produced results comparable with those for the pupils. It is concluded that chronic overloading, rather than faulty mechanics, is the dominant factor in the genesis of anterior knee pain in adolescent patients.