Heterotopic ossification following total elbow arthroplasty: a comparison of the incidence following elective and trauma surgery.

Aims: The primary aim of this retrospective study was to identify the incidence of heterotopic ossification (HO) following elective and trauma elbow arthroplasty. The secondary aim was to determine clinical outcomes with respect to the formation of heterotopic ossification. Patients and Methods: A total of 55 total elbow arthroplasties (TEAs) (52 patients) performed between June 2007 and December 2015 were eligible for inclusion in the study (29 TEAs for primary elective arthroplasty and 26 TEAs for trauma). At review, 15 patients (17 total elbow arthroplasties) had died from unrelated causes. There were 14 men and 38 women with a mean age of 70 years (42 to 90). The median clinical follow-up was 3.6 years (1.2 to 6) and the median radiological follow-up was 3.1 years (0.5 to 7.5). Results: The overall incidence of HO was 84% (46/55). This was higher in the trauma group (96%, 25/26) compared with the elective arthroplasty group (72%, 21/29) (p = 0.027, Fisher's exact test). Patients in the trauma group had HO of higher Brooker class. The presence of HO did not significantly affect elbow range of movement within the trauma or elective groups (elective arthroplasty, Mann-Whitney U test, p = 0.070; trauma arthroplasty, p = 0.370, Mann-Whitney U test). Conclusion: HO after total elbow arthroplasty is seen more commonly than previously reported. We have reported a significantly higher rate of HO in TEAs performed for trauma than those performed electively. Cite this article: Bone Joint J 2018;100-B:767-71.

Rifampicin prophylaxis for throat carriage of Haemophilus influenzae type b in patients with invasive disease and their contacts.

OBJECTIVE: To determine rates of colonisation with Haemophilus influenzae type b among household contacts of children with invasive H influenzae type b disease; compliance among medical staff with recommendations for use of rifampicin prophylaxis; and effects of rifampicin treatment in H influenzae type b colonisation of patients and contacts. DESIGN: Prospective study of patients and their household contacts. SETTING: Royal Children's Hospital (the major paediatric hospital) in Victoria, Australia, with catchment population of 4.2 million, including 300,000 children aged under 5 years. SUBJECTS: 234 patients (age range 6 weeks to 8 years) with 235 episodes of all types of invasive H influenzae type b disease admitted during 1988-9 and their contacts. MAIN OUTCOME MEASURES: Positive cultures of H influenzae type b from throat swabs taken at admission and six weeks subsequently; recording of rifampicin prophylaxis. RESULTS: The percentage of patients with positive throat cultures fell from 69% (33/48) on day 1 of admission to 9% (4/47) after three days' treatment; at six weeks' follow up 32% (32/99) of patients who had not received rifampicin and 8% (5/61) who had, had positive throat cultures. Among household contacts, 33% (62/190) of children and 7% (25/359) of adults were colonised, and the colonisation rates were similar in contacts of patients with all types of H influenzae type b disease. Rifampicin prophylaxis was indicated in 85 families; in 34% it was not prescribed at all for contacts and in 41% not as recommended. The colonisation rates at follow up were significantly less in siblings given rifampicin (12%, 9/78), particularly in families in which all members were treated (3%), than in those in which they were not (36%) (odds ratio 21.5; 95% confidence interval 3.0 to 103.4). CONCLUSIONS: The rate of throat colonisation with H influenzae type b was similar among siblings of children with all types of invasive H influenzae type b disease. Colonisation in contacts can be reduced by rifampicin prophylaxis, but some contacts remained colonised or were recolonised by the time of follow up. Medical staff complied poorly with current recommendations for rifampicin prophylaxis, which reduces its intrinsically limited value in preventing H influenzae type b disease.

Outer membrane protein subtypes of Haemophilus influenzae type b isolates causing invasive disease in Victoria, Australia, from 1988 to 1990.

Outer membrane protein subtyping of 187 isolates of Haemophilus influenzae type b (Hib), isolated from children with invasive Hib disease in Victoria, Australia, showed that a single outer membrane protein subtype (1VA) was responsible for 83% of the infections. It was identical to that responsible for the majority of cases of invasive Hib disease in Europe.

Antibodies to Haemophilus influenzae type b outer membrane proteins in children with epiglottitis or meningitis and in healthy controls.

The two most common manifestations of Haemophilus influenzae type b (Hib) infection in Western communities are meningitis and epiglottitis. The role of antibodies against outer membrane proteins (OMP) in the pathogenesis of these diseases was investigated by Western blotting (immunoblotting) with an OMP antigen prepared from a local Hib strain. Acute- and convalescent-phase serum samples from 25 children with epiglottitis and 20 with meningitis and single serum samples from 19 control children in the same age group were tested. Western blots were evaluated quantitatively by use of graphs generated from a densitometer. OMP antibody was detected in all sera from patients and controls. There was no significant difference between the mean antibody level in acute-phase sera from children with meningitis (336 +/- 143 arbitrary units) and those from children with epiglottitis (286 +/- 134 arbitrary units). However, the mean OMP antibody level in sera from healthy controls, with no known history of Hib disease, was significantly higher than that in sera from patients with Hib disease within 2 days of admission to the hospital (patients [n = 35], 282 +/- 144; controls [n = 19], 425 +/- 236; P = 0.007). The difference was due mainly to higher levels, in control sera, of antibody against four proteins, one of which is either P1 or a comigrating protein of 49 kDa. The finding of higher levels of OMP antibody in healthy controls suggests a protective role for antibodies directed against one or more OMP. This information could be exploited in future vaccine development.

A national collaborative study of resistance to antimicrobial agents in Haemophilus influenzae in Australian hospitals. The Australian Group for Antimicrobial Resistance (AGAR).

An Australia-wide survey of the prevalence of resistance to antimicrobial agents among Haemophilus influenzae was conducted on clinically significant isolates collected between July 1988 and September 1990. Laboratories from the capital cities of each Australian state and territory participated. Nine hundred and seventy clinical isolates were examined for beta-lactamase production and the MICs of ampicillin, coamoxiclav, chloramphenicol, cefaclor, ceftriaxone, cefotaxime, tetracycline, rifampicin, trimethoprim, sulphamethoxazole and co-trimoxazole were determined using the NCCLS agar dilution method with Haemophilus Test Medium. A smaller number of isolates were tested against penicillin V, penicillin G, ciprofloxacin, piperacillin and erythromycin in addition. The proportion of beta-lactamase producing strains was higher among invasive strains (21.6%) than non-invasive strains (14.2%) and varies considerably between states. The highest prevalence of ampicillin resistance was found in invasive strains from Canberra (40.8%), the lowest in non-invasive strains from Adelaide (5.1%). Paradoxically, in non-invasive strains, although beta-lactamase production was less common, resistance to other antimicrobials was commoner than in invasive strains and also varied between states.