Hip resurfacing following previous proximal femoral osteotomy

Until recently, the options for patients with a degenerative hip and a previous femoral osteotomy included arthrodesis, total hip arthroplasty with osteotomy or CADCAM total hip arthroplasty. Technological improvements have allowed the reintroduction of hip resurfacing. We report the results of hip resurfacing in four patients with previous valgus or extension proximal femoral osteotomies. Patients were assessed for pre and post-operative pain, walking distance and range of movement. All patients had an abnormal angulation, of the femoral neck, of 30 degrees or more in either coronal or sagittal plane. They are within the severe group of disordered proximal femoral anatomy according to Harris et al. The mean age at operation was 32 years (range 30 - 34). The mean follow-up was 3 years (range 1 - 8). Postoperatively no patient required analgesia and all patients had a minimum uninterrupted walking ability of 30 or more minutes with the exception of the patient who had undergone previous leg lengthening. We recommend this comparatively straightforward operation compared to current alternatives. (Hip International 2005; 15: 119-22).

Trachipleistophora hominis infection in the myocardium and skeletal muscle of a patient with AIDS

OBJECTIVES

To review the literature relevant to microsporidial infection of muscle and to describe a case of human microsporidial infection involving both skeletal and cardiac muscle.

METHODS

Samples from an AIDS patient with myositis have been examined by light and electron microscopy.

RESULTS

We describe the findings at autopsy of a 47 year old Australian male with late stage AIDS, who had skeletal and cardiac muscle involvement with the microsporidian Trachipleistophora hominis. This is the third definitively identified case of human T. hominis infection and the first to describe infection of the myocardium.

CONCLUSIONS

Microsporidial infection of muscle is rare in humans, but more work is needed to elucidate both the organisms and routes of transmission of this group of parasitic protozoa.

A survey of the perspectives of specialist palliative care providers in the UK of inpatient respite

One of the major reasons for admission of patients to hospital in late stage disease is the inability of carers to continue to provide care at home. Specialist palliative care services have typically admitted patients for acute symptom control, terminal care and respite care to benefit them and their carers. This paper reports the results of a cross-sectional survey of inpatient respite care provision provided by specialist palliative care services and hospices in the UK. A structured questionnaire was mailed to 242 clinical services managers listed in the Hospice Information Directory in 2003. A 69% response rate was achieved. The questionnaire explored the nature of respite services, their purpose, organization, delivery and examined definitions used. The analysis indicated that 80% of the sample provided inpatient respite care. Most inpatient respite admissions were planned, of fixed duration (7-14 days) and were intended to benefit patients and carers. There was some evidence that respite provision was regarded as a lower priority than admissions for symptom control and terminal care, and that patients' needs were prioritized over those of carers. Only 10% of services conducted regular, routine audit, with very few seeking the views of service users. Findings suggest that carers' needs and wishes are not prioritized by specialist palliative care services offering inpatient respite, which may mean that they find it difficult to maintain their caregiving roles over longer disease trajectories or in the face of overwhelming demands.

Cryptococcal meningitis in two apparently immunocompetent Maltese patients

Two cases of cryptococcal meningitis occurring in immunocompetent men are described. The first case involves a farmer in whom cryptococcal meningitis was rapidly diagnosed using direct microscopy, latex antigen tests and culture of cerebrospinal fluid (CSF). In the second case, initial mycological tests on CSF (direct microscopy and culture) were repetitively negative and latex antigen tests gave unconvincing results. The patient was started on triple antituberculosis therapy, on which he improved immediately; therapy was continued for 1 year with the patient remaining well. However, within 1 week of stopping therapy, he had to be readmitted with neurological signs and symptoms. Culture of CSF this time yielded Cryptococcus neoformans and the antigen test was consistently positive. These are the first reported cases of cryptococcal meningitis in immunocompetent patients in Malta.

ProteinDBS: a real-time retrieval system for protein structure comparison

We have developed a web server (ProteinDBS) for the life science community to search for similar protein tertiary structures in real time. This system applies computer visualization techniques to extract the predominant visual patterns encoded in two-dimensional distance matrices generated from the three-dimensional coordinates of protein chains. When meaningful contents, represented in a multi-dimensional feature space, have been extracted from distance matrices, an advanced indexing structure, Entropy Balanced Statistical (EBS) k-d tree, is utilized to index the data. Our system is able to return search results in ranked order from a database with 46 075 chains in seconds, exhibiting a reasonably high degree of precision. To our knowledge, this is the first real-time search engine for protein structure comparison. ProteinDBS provides two types of query method: query by Protein Data Bank protein chain ID and by new structures uploaded by users. The system is hosted at http://ProteinDBS.rnet.missouri.edu.

Short-term results of hemi-resurfacing for osteonecrosis of the femoral head

Published evidence has supported the use of femoral head resurfacing for patients with osteonecrosis of the femoral head. Between June 1999 and April 2001 we prospectively studied 15 femoral heads resurfaced in 12 patients with the Conserve Resurfacing Hemiarthroplasty. The male to female ratio was 8:4 and the mean age 38.7 years (range 26-60). The mean follow-up was 22.8 months (range 4-36). The senior author performed all procedures. There was one case of Ficat stage II, 9 cases of stage III and 5 cases of early stage IV. The mean time from onset of symptoms to surgery was 33.5 months (range 9-60). There were no intra or post-operative complications associated with any of the hemiarthroplasty procedures.

RESULTS

Nine of the fifteen patients had a poor result that warranted revision surgery within two years of prosthesis implantation. We conclude that in our hands the results of femoral resurfacing hemiarthroplasty are unpredictable and advise caution when recommending the procedure to patients with osteonecrosis of the femoral head. (Hip International 2004; 14: 174-81).

The use of tranexamic acid to reduce blood loss during total knee arthroplasty

HYPOTHESIS

The fall in haemoglobin following unilateral total knee arthroplasty is reduced by tranexamic acid administration.

METHODS

60 patients were studied in total, 30 received tranexamic acid 10 mg/kg on induction and a further dose shortly before the release of the tourniquet. Surgery was performed by the senior author in a standardised fashion using the Freeman Samuelson cemented total knee replacement. Haemoglobin levels were measured 2 weeks pre and 3 days post operatively. Any complications were noted. A control group was matched using the Bone and Joint Research Unit database for age, sex, disease and pre-operative haemoglobin level. This group had been monitored in the same way as the group treated with tranexamic acid.

RESULTS

In the group receiving no tranexamic acid the mean fall in haemoglobin was 2.8 g/dl (95% CI of mean 2.5-3.2) and in the group treated with tranexamic acid 1.7 g/dl (95% CI of mean 1.3-2) P<0.01. There were no complications in either group.

CONCLUSIONS

The administration of tranexamic acid is an effective method of reducing the haemoglobin fall following knee arthroplasty.

Systemic exposure, tolerability, and efficacy of pimecrolimus cream 1% in atopic dermatitis patients

AIMS

To measure pimecrolimus blood concentrations and to evaluate tolerability and efficacy in children and infants treated topically for atopic dermatitis with pimecrolimus cream 1% for three weeks.

METHODS

Three open label, non-controlled, multiple topical dose studies were conducted in children aged 8-14 years (study A, ten patients), and in infants aged 8-30 months (study B, eight patients) and 4-11 months (study C, eight patients). Pimecrolimus blood concentrations were determined on days 4 and 22 of treatment, and at end of study. Efficacy was assessed using the Eczema Area and Severity Index (EASI).

RESULTS

Pimecrolimus blood concentrations were consistently low, typically (81%) below 1 ng/ml, with more than half of the measurements below the assay limit of quantitation (0.5 ng/ml) in studies A and B. The highest blood concentration measured throughout the three studies was 2.6 ng/ml. The cream was well tolerated, locally and systemically. The most common adverse event suspected to be related to study medication was a transient mild to moderate stinging sensation at the application site in 5/26 patients. There was no indication of any systemic adverse effect. The patients responded well to therapy with a rapid onset of action, usually within four days. Median reductions of EASI from baseline at day 22 were 55% (study A), 63% (study B), and 83% (study C).

CONCLUSION

Three weeks treatment of children and infants with extensive atopic dermatitis, using pimecrolimus cream 1% twice daily, is well tolerated and results in minimal systemic exposure, at which no systemic effect is expected.

Hydroxyapatite-coated femoral components in total knee arthroplasty: medium term results

Thirty-six consecutive total knee arthroplasties with hydroxyapatite (HA)-coated femoral components were prospectively followed up according to a standardised protocol for a mean period of 10 years (range, 7-11 years). Clinical and radiologic examination was performed at each follow-up evaluation. One patient (1 knee) was lost to follow up at 7 years, and 4 other patients (6 knees) died. Radiographs were studied for signs of loosening and presence of lucencies. Survival analysis was performed using a life table with revision as the criterion for failure. Two knees (1 patient) were revised because of aseptic loosening. The tibial component of one other knee was revised because of osteolysis in the medial tibial condyle. In the remaining knees, no radiologic evidence of loosening was seen. The survival of the femoral component at a mean follow-up time of 7 years, when 31.5 knees were at risk, was 94% with revision for femoral aseptic loosening as the end point. At 10 years, when 24 knees were at risk, the survival remained 94%.

Gastroduodenal tolerability of lumiracoxib vs placebo and naproxen: a pilot endoscopic study in healthy male subjects

BACKGROUND

Lumiracoxib (Prexige) is a cyclooxygenase-2 (COX-2) selective inhibitor.

AIM

To compare the gastroduodenal tolerability of lumiracoxib with placebo and naproxen in a randomized, parallel-group, double-blind study.

METHODS

: Sixty-five healthy male subjects were randomized to receive 8 days' dosing with lumiracoxib 200 mg twice daily (b.d.) (n = 21), placebo (n = 22) or naproxen 500 mg b.d. (n = 22). Endoscopic evaluations of gastric and duodenal mucosae were conducted at baseline and after 8 days' dosing. Serum was assayed for ex-vivo concentrations of thromboxane B2 (TxB2) to determine cyclooxygenase-1 (COX-1) inhibitory activity.

RESULTS

Sixty subjects (20 per group) completed the study. No gastroduodenal erosions were observed in subjects receiving lumiracoxib. Thirteen subjects receiving naproxen developed duodenal erosions. At the gastric site, one subject in each of the naproxen and placebo groups had erosions; one subject receiving naproxen also developed a small asymptomatic gastric ulcer. Gastrointestinal adverse events accounted for 42.3% of all adverse events, occurring in 3/21, 4/22 and 6/22 of the lumiracoxib, placebo and naproxen groups, respectively. TxB2 levels were similar for patients receiving placebo or lumiracoxib, but were reduced by > 95% in patients receiving naproxen, compared with placebo.

CONCLUSIONS

Multiple doses of lumiracoxib resulted in gastroduodenal tolerability similar to placebo and superior to naproxen.

Atypical herpes type 2 encephalitis associated with normal MRI imaging

We describe a case of chronic atypical herpes simplex type 2 encephalitis in an immunocompromised 68 year old man presenting with headache and cognitive changes without focal neurological or MRI findings. To our knowledge this is the first described case of herpes simplex encephalitis associated with normal MRI brain imaging and non-focal neurological examination. This further expands the range of clinical presentations that may be associated with herpes simplex encephalitis and emphasises the value of PCR for herpes simplex virus in the investigation of encephalitis regardless of imaging findings.

Effect of lidocaine and NMDA injections into the medial pontobulbar reticular formation on mastication evoked by cortical stimulation in anaesthetized rabbits

Neurons of the dorsal nucleus reticularis pontis caudalis (nPontc) fire rhythmically during fictive mastication, while neurons of the ventral half tend to fire tonically (Westberg et al., 2001). This paper describes the changes in the pattern of rhythmical mastication elicited by stimulation of the sensorimotor cortex during inhibition or excitation of neurons in this nucleus and adjacent parts of nucleus reticularis gigantocellularis (Rgc) in the anaesthetized rabbit. Masticatory movements and electromyographic (EMG) activity of the masseter and digastric muscles produced by cortical stimulation were recorded before, during and after injections of a local anaesthetic (lidocaine) or excitatory amino acid N-methyl-d-aspartate (NMDA) into nPontc and Rgc through a microsyringe with attached microelectrode to record neuronal activity. Lidocaine inhibited local neurons and modified the motor program, and the effects varied with the site of injection. Most injections into the ventral half of nPontc increased cycle duration, digastric burst duration and burst area. The action of lidocaine in dorsal nPontc was more variable, although burst duration and area were often decreased. The effects on the muscle activity were always bilateral. Lidocaine block of the rostromedial part of Rgc had no effect on movements or on EMGs. Injections of NMDA excited local neurons and when injected into ventral nPontc, it completely blocked mastication. Dorsal injections either had no effect or increased cycle frequency, while decreasing burst duration and area. No increases in EMG burst duration or area were observed with NMDA. Our findings suggest that neurons of ventral nPontc tonically inhibit other parts of the central pattern generator during mastication, while dorsal neurons have mixed effects. We incorporated these findings into a new model of the masticatory central pattern generator.

A femoral component with proximal HA coating. An analysis of survival and fixation at up to ten years

We describe the survival at ten years of 100 femoral components of the Freeman hip prosthesis. It is proximally hydroxyapatite (HA)-coated and was fixed without cement. Radiological assessment identified radiolucent lines (RLLs) and lytic lesions and was used to measure migration. The criterion of failure was revision or impending revision for aseptic femoral loosening. No femoral components were revised or are awaiting revision for aseptic loosening, giving 100% survival at ten years (95% confidence interval, 95.7 to 100), although 59 were at risk at ten years. Two components were revised for fracture of a ceramic head with damage to the trunnion. Although well fixed in each, for survival analysis we evaluated the hip as if the patient had died. Twelve acetabular components were revised and at each operation the femoral component was found to be well fixed, was not disturbed and remained in the survival analysis. Three patients were lost to follow-up, and 12 died with well-functioning prostheses. Radiologically, all except one of the components appeared to be well fixed with no RLLs and no lytic lesions at the latest follow-up. The mean vertical migration was 0.4 mm at one year, 0.8 mm at two years and 1.4 mm at ten years. One component had migrated 7.6 mm at ten years (2.1 mm in year 1) and developed RLLs in Gruen zones I and II. The symptoms, however, were only minor and revision was not indicated. Our study has shown that proximal HA coating gives effective fixation for a femoral component.

Failure of an uncemented non-porous metal-backed prosthesis with augmentation using impacted allograft for acetabular revision 12- to 17-year results

We have reviewed 29 patients (30 hips) who had undergone revision total hip arthroplasty using a Freeman metal-backed acetabular component and acetabular impaction allografting. The mean follow-up was for 153 years (12 to 17). Five patients (5 hips) died with the prosthesis in situ and four (4 hips) were lost to follow-up. Twelve hips had failed and in the remaining nine there were minor symptoms. The mean time to failure requiring further surgery was nine years. Excluding patients who were lost to follow-up or had died, 72% of the hips were radiologically loose at the last review. The commonest pattern in those requiring revision was failure of the reinforcement ring in adduction with remodelling of the medial wall. Of the nine patients who had not undergone revision, one with bilateral replacements had no current radiographs and only three of the remaining seven replacements had no radiological signs of loosening. The short-term results for this technique have been reported to be satisfactory, but in the long term they are not. The factors associated with failure include the design of the prosthesis, which has been implicated in disappointing long-term results when used in primary arthroplasty, but not with the frequency of failure found in this series. It seems that the reliance on peripheral screw fixation over a bed of allograft without bridging the graft does not provide sufficient stability to allow incorporation of the graft.

Should the cement mantle around the femoral component be thick or thin?

We have compared the survival and radiological outcome at ten years after total hip replacement using two techniques for preparing the femoral canal. The same prosthesis was used throughout and all operations were performed by the same surgical team. In technique 1 the canal was over-reamed by 2 mm and in technique 2 it was reamed to the same size as the prosthesis. Technique 1 was performed on 92 patients and technique 2 on 97 patients. The survival at ten years was 97.2% (90.6 to 99.2) for technique 1 and 98.8% (92.9 to 99.8) for technique 2. Vertical migration was greater in technique 1 (1.8 mm versus 1.0 mm at five years; p = 0.36). There were significantly more lytic lesions and radiolucent lines at five years (p = 0.0061) with technique 1. We conclude that technique 2 is not worse and may produce better long-term results than current teaching suggests.

Impact of legume 'break' crops on the yield and grain quality of wheat and relationship with soil mineral N and crop N content

The effect of annual 'break' crops on the yield and protein content of wheat was investigated over 3 seasons on a Red Kandasol on the south-western slopes of New South Wales. The 'break' crops included lupin and pea grown for grain, pea and vetch managed for silage, clovers managed for silage or hay, and vetch and clovers managed for green manuring. Wheat was sown for 2 years following the legume year, or canola and wheat followed the legumes. Averaged over 3 experiments the yields of first crop wheat following pea or vetch silage crops were comparable with those after grain pea. Yields following clover forage conservation crops or green manures exceeded those after grain pea by at least 0.41 t/ha; average yield increase after clover green manure was 0.93 t/ha. In one experiment, yields of second crop wheat were greater, by up to 0.37 t/ha, after forage conservation or green manure legume 'breaks' than after grain legumes. In 2 experiments, second crop wheat yields were greater after a first crop of canola than a first crop of wheat. Compared with continuous wheat yield, aggregate mean wheat yield increases were 3.5–4 t/ha following grain legumes, pea, and vetch silage crops, but 5.3–6.3 t/ha following clover forage conservation and green manure crops. However, the relative effects of legume treatments on wheat yield were significantly seasonally dependent. Yield and grain protein variation in wheat after legumes was significantly correlated with variation in mineral N at wheat establishment. However, in one experiment, yield was correlated only with variation in mineral N below the 20-cm soil depth, whereas protein was correlated only with variation in mineral N above the 20 cm soil depth. Yield increases in first crop wheat did not occur at the expense of grain protein.

Impact of legume 'break' crops on the residual amount and distribution of soil mineral nitrogen

Important factors in the successful uptake of grain legumes by cereal growers have been their capacity to increase soil N and control cereal disease, as these have underpinned high yields in following wheat crops. However, alternative 1-year legume crops are required to introduce additional biodiversity and management flexibility for cereal growers. The effects on soil mineral N and potential contribution to soil total N of other legume enterprises were studied. These included vetch (Vicia bengalhensis) or clovers (mix of Trifolium alexandrinum, T.�versiculosum, T. resupinatum) managed for green manure; pea (Pisum sativum), vetch, or clovers managed for silage; and clovers managed for hay. These were compared with pea and lupin (Lupinus angustifolius) managed for grain production. Wheat was also included as a control. The legumes were grown in acidic Red Kandasol soil at Wagga Wagga in southern New South Wales, in 1996, 1997, and 1998. Mineral N was measured in the autumn or winter of seasons 1997 and 1998 respectively. Amounts of stubble residue N were measured in all seasons. The green manure crops, particularly vetch, produced more mineral N than both grain legumes. The forage conservation crops (silage or hay) produced similar amounts of mineral N to grain pea and more than grain lupin. For the grain and green manure legume crops, variation in amounts of mineral N was explained by the total N content of legume stubble residue, but for the forage conservation crops, more mineral N was measured than was predictable from stubble N. The amounts of mineral N at different soil depths differed between legume treatments and experiments (sites and years). Based only on above-ground plant N, the green manure crops contributed more to increasing total soil N than grain legumes; in turn, the grain legumes contributed more than the forage conservation crops. It was concluded that alternative annual legume enterprises to grain legumes may provide at least similar enrichment of soil mineral N early in the following season, and that all annual legume enterprises may accumulate nitrate deep in the soil profile in some seasons.

Origin and distribution of polycyclic aromatic hydrocarbons in surficial sediments from the savannah river

Surface sediments collected from the Savannah River, located in the southeastern state of Georgia, USA, in June-July 1994 were analyzed for individual polycyclic aromatic hydrocarbons (PAHs). Three subdivisions of the river were identified for the study: upstream from, adjacent to, and downstream from the city of Savannah. There was high spatial variability in the total PAH (SigmaPAH) concentrations that ranged from 29 to 5,375 ng/g with an average concentration of 1,216 +/- 1,161 (SD). Of the three subdivisions, the highest SigmaPAH concentrations were in the middle segment, which was adjacent to urban and industrial areas. To elucidate sources, molecular indices based on indices among phenanthrene versus anthracene and fluoranthene versus pyrene were used to determine pyrogenic and petrogenic sources, respectively. These indices have been used by other authors to differentiate sources. In most cases, PAHs in sediments nearest the city of Savannah were of high temperature and pyrogenic origin. These pyrogenic PAHs were highly associated with toxicity to benthic organisms. The two-ringed naphthalene and substituted naphthalenes, which are petroleum-related PAHs, were significantly higher in the lower section of the river relative to the subdivisions. This river segment receives inputs primarily from shipping and boating traffic. Perylene, which is indicative of nonanthropogenic terrestrial inputs of carbon, had the highest concentration among the individual PAHs measured. High perylene concentrations were found at stations located upstream and adjacent to forested terrain and where salinity level was low. To discriminate pattern differences and similarities of individual PAHs among samples, principal component analysis (PCA) was performed on the more hydrophobic and persistent nonalkylated PAHs. These differences and similarities were used to infer perylene origin. PCA was performed on 14 nonalkylated PAHs that was normalized to the sum of nonalkylated PAHs, using a correlation matrix. Generally, the PAHs were separated into group patterns according to chemical and physical properties associated with log K(OW), except perylene. Perylene, a five-ringed PAH, was distinctly separated from the other five-ringed PAHs. The sources for perylene are likely from biogenic, terrestrial precursors. The collected data show that pyrogenic PAHs were highly associated with biological effects on benthic organisms, based on bioassay results. Perylene, a nonanthropogenic PAH, was found throughout the river and constituted a large percentage of total PAHs in the upper river.

Consensus neuropathological diagnosis of common dementia syndromes: testing and standardising the use of multiple diagnostic criteria

The aim of this study was to assess the variation between neuropathologists in the diagnosis of common dementia syndromes when multiple published protocols are applied. Fourteen out of 18 Australian neuropathologists participated in diagnosing 20 cases (16 cases of dementia, 4 age-matched controls) using consensus diagnostic methods. Diagnostic criteria, clinical synopses and slides from multiple brain regions were sent to participants who were asked for case diagnoses. Diagnostic sensitivity, specificity, predictive value, accuracy and variability were determined using percentage agreement and kappa statistics. Using CERAD criteria, there was a high inter-rater agreement for cases with probable and definite Alzheimer's disease but low agreement for cases with possible Alzheimer's disease. Braak staging and the application of criteria for dementia with Lewy bodies also resulted in high inter-rater agreement. There was poor agreement for the diagnosis of frontotemporal dementia and for identifying small vessel disease. Participants rarely diagnosed more than one disease in any case. To improve efficiency when applying multiple diagnostic criteria, several simplifications were proposed and tested on 5 of the original 20 cases. Inter-rater reliability for the diagnosis of Alzheimer's disease and dementia with Lewy bodies significantly improved. Further development of simple and accurate methods to identify small vessel lesions and diagnose frontotemporal dementia is warranted.

The natural history and significance of radiolucent lines at a cemented femoral interface

We studied 185 total hip replacements and related the identification of radiolucent lines (RLLs) at two years to the later development of lytic lesions and loosening. Linear polyethylene wear was also measured. RLLs appeared in 34 hips at a mean of 2.0 years after operation, and lytic lesions in ten hips at 5.7 years. Of 151 THRs without RLLs there was neither rapid migration nor loosening and only one developed a possible lytic lesion. Of 23 hips with non-progressive RLLs there was neither rapid migration nor loosening, but six developed a lytic lesion. By contrast, 11 THRs with progressive RLLs migrated rapidly and seven developed a lytic lesion. Six THRs with progressive RLLs failed. The wear rates were the same in all groups, although limited numbers were available for study. If the surgeon achieves secure initial fixation as shown by slow or no migration and no RLLs during the first two years, it is likely that no lytic lesions will develop by five years or aseptic loosening by ten years. If an imperfect, but adequate, interface is achieved, as shown by slow migration and non-progressive RLLs lytic lesions adjacent to the RLLs may develop by five years, but aseptic loosening will be unlikely at ten. Insecure initial fixation, as shown by more rapid migration and progressive RLLs at two years, is likely to lead to the formation of lytic lesions at five years and loosening at ten. The outcome after THR is therefore determined at the initial operation and may be predicted at two years. The presence of lytic lesions reflects soft tissue at the interface as shown by the RLLs which accompany and promote loosening but, in our study, did not cause it.