The study aimed to determine how well recorded pain levels and range of motion relate to patients' reported levels of functional ability/disability pre- and post- total hip arthroplasty.

Range of motion (ROM), Oxford Hip Score (OHS) and Self-Report Harris Hip Score (HHS) were recorded pre-operatively and 3 months post-total hip arthroplasty. Pearson's correlation coefficients were calculated to determine the strength of the relationships both pre- and post-operatively between ROM (calculated using the HHS scoring system) and scores on OHS and HHS and response relating to pain from the questionnaires (question 1 HHS and questions 1, 6, 8, 10, 11 and 12 of OHS) and overall scores.

Only weak relationships were found between ROM and HHS pre- (r = 0.061, n = 99, p = 0.548) and post-operatively (r = 0.373, n = 66, p = 0.002). Similar results were found for OHS, and when ROM was substituted for flexion range. In contrast, strong correlations were found between OHS pain component and HHS pre- (r = -0.753, n = 107, p<0.001) and post-operatively (r = -0.836, n = 87, p<0.001). Strong correlations were also found between the OHS pain component correlated with the HHS functional component only (HHS with score for questions relating to pain deducted) pre- (r = -0.665, n = 107, p<0.001) and post-operatively (r = -0.688, n = 87, p<0.001). Similar results were found when the HHS pain component was correlated with OHS.

In orthopaedic clinical practice ROM is routinely used to assess the success or failure of arthroplasty surgery. These results suggest that this should not be done. Instead, asking the patient the level of pain that they are experiencing may be a good determinant of level of function. The results of this study may aid the development of arthroplasty scoring systems which better assess patients' functional ability.

Introduction: The use of prolonged courses of parenteral or oral antibiotic therapy in combination with a two-stage exchange procedure in the management of the infected total hip arthroplasty is reported by many major series.

Methods: We present a series of 114 patients, all with microbiologically proven chronic deep infection, treated with a two-stage exchange with antibiotic loaded cement and where a prolonged course of antibiotic therapy has not been used. The mean follow-up for all patients is 74months (range 2–175months) with all surviving patients having a minimum 2 year follow-up.

Results: Infection was successfully eradicated in 100 patients (88%). The infection cure rate in our series is similar to that reported elsewhere where prolonged adjuvant antibiotic therapy was used.

Discussion: Using the technique described a prolonged course of systemic antibiotics does not appear to be necessary; the high costs of antibiotic administration, both to the patient and care facility are not incurred.

Introduction: Bone cements produced by different manufacturers vary in their mechanical properties and antibiotic elution characteristics. Small changes in the formulation of a bone cement, which may not be apparent to surgeons, may also affect these properties. The manufacturing method of Palacos bone cement with added gentamicin has recently changed. We have carried out a study to examine the mechanical characteristics and antibiotic elution of Schering-Plough Palacos (‘old’ version), Heraeus Palacos (‘new’ version) and Depuy CMW Smartset bone cements.

Methods: Schering-Plough Palacos R40G (contains 0.5g gentamicin per 40g mix), Heraeus Palacos R+G (contains 0.5g gentamicin per 40g mix) and Depuy-CMW Smartset GHV (contains 1g gentamicin per 40g mix) were used. 40g samples of the three cements with no additional vancomycin, 1g and 2g vancomycin were prepared by a standard method using vacuum mixing in a syringe. Antibiotic elution over a five week period was measured using an immunoassay method. Standard mechanical testing was carried out according to methods defined in ISO 5833.

Results: Both Heraeus Palacos and Smartset bone cements performed significantly better than Schering-Plough Palacos in terms of mechanical characteristics both with and without additional antibiotics. All cements show a deterioration in flexural strength with increasing addition of vancomycin although staying above ISO minimum levels. Both Heraeus Palacos and Smartset elute significantly more gentamicin cumulatively than Schering-Plough Palacos. Smartset elutes significantly more vancomycin cumulatively compared with Heraeus Palacos.

Discussion: Both Heraeus Palacos and Smartset Bone cements elute significantly more gentamicin than Schering-Plough Palacos with no deterioration in mechanical characteristics. Smartset also elutes significantly more vancomycin than Heraeus Palacos without adverse affect on mechanical characteristics. Although marketed as the ‘original’ Palacos, Heraeus Palacos has significantly altered mechanical and antibiotic elution characteristics compared with previous versions.

Introduction: Deep infection is a devastating complication following hip arthroplasty. In the early 1970’s Staphylococcus Aureus (SA) was believed to be the causative organism in most cases and Coagulase Negative Staphylococccus (CNS) was widely regarded as a contaminant. It subsequently became recognised that the majority of infections are caused by CNS rather than SA, probably due to the use of peri-operative antimicrobial agents and laminar air flow in theatre.

Aims: The aim of this study was to look at the causative organisms in patients with an infected total hip replacement to see if the pattern of infection has changed with time.

Methods: Between February 1999 and November 2004, 95 patients underwent 1^st stage revision surgery at the Northern General Hospital for definite infection following total hip replacement. At least 5 tissue samples were taken at the time of surgery prior to antibiotic administration. Infection was confirmed when at least 3 of the samples were positive on microbiological culture. We retrospectively reviewed the records of these patients and identified the causative organisms.

Results: The 95 patients were infected with 130 different organisms. Of these 32% were SA including MRSA (7.2%), 27% CNS, 13.6% Enterococcus, 4.8% pseudomonas and 3.2% Streptococcci. 29% of patients had polymicrobial infection.

Discussion: Data published in the literature as well as historical data from our unit suggest that CNS is by far the most common organism causing prosthetic hip joint infection. Our results however, show a recent decrease in the proportion of CNS and an increase in SA and polymicrobial infection.

Introduction: It is common practice to use additional antibiotics in bone cement for revision hip surgery. Ideally antibiotic elution would initially be rapid and then reduce to zero in order to reduce the risk of antibiotic resistance developing. There is evidence that the addition of antibiotics to bone cement leads to deterioration in mechanical properties. We have carried out a study to see if the addition of vancomycin to Palacos R40G and Smartset GHV affects their in-vitro antibiotic elution and mechanical properties.

Methods: Palacos R40G (contains 0.5g gentamycin per 40g mix) and Smartset GHV (contains 1g gentamycin per 40g mix) were used. 40g samples of the two cements with no additional vancomycin, 1g and 2g vancomycin were prepared by a standard method using vacuum mixing in a syringe. Antibiotic elution over a five week period was measured using an immunoassay method. Standard mechanical testing was carried out according to methods defined in ISO 5833.

Results: Smartset GHV eluted double the quantity of gentamycin as Palacos R40G, as would be expected. Both cements eluted more gentamycin when vancomycin was added. Smartset appears to elute more vancomycin than Palacos initially and then shows a more rapid tailing off. The mechanical properties of the two cements were the same with no statistical differences found between them. Both showed deterioration in flexural strength with addition of increasing vancomycin.

Discussion: Smartset may have improved qualities of antibiotic elution as compared with Palacos with similar mechanical properties. The presence of higher initial quantities of gentamycin does not lead to reduced mechanical properties.

Introduction: The correct identification of the infecting micro-organism in prosthetic joint infections is difficult and there is no single method that is wholly reliable. We report a novel method intended to improve accuracy by disrupting the biofilm surrounding the prosthesis and transferring samples rapidly to culture medium.

Method: Explanted prostheses from 20 revision operations were sampled by pressing a microbiology swab or by passing a No.10 surgical blade along it. The sample so obtained was plated immediately in the operating theatre onto horse-agar petri dishes. These were incubated in aerobic conditions in the laboratory. Culture results were compared with those obtained from our standard detection method using multiple tissue samples with are plated or grown in prolonged aerobic and anaerobic culture broth.

Results: The method proved practical to perform in practice. When compared with multiple tissue samples as the standard, the Positive Predictive Value was 90%, Negative Predictive Value 80%, sensitivity 82%, specificity 89%. In 4 of the 10 true positive samples, the theatre-inoculated samples yielded early results within 3 days, while conventional method yielded positives only later on prolonged culture.

Discussion: The above pilot is to continue and has started to alter our practice in sample taking. Blade-scrape does appear to penetrate the biofilm successfully. Growing confidence in interpretation and ease in reading the plates mean that in certain cases, we consider the results to be more reliable than traditional tissue culture. Direct plating also reduces the chance of bacterial overgrowth in broth inhibiting colonies of secondary infective organisms. Further refinement is needed, particularly with regard to anaerobic bacteria. Inaccuracies have resulted when agar plates are allowed to go out of date.

Bone cements produced by different manufacturers vary in their mechanical properties and antibiotic elution characteristics. Small changes in the formulation of a bone cement, which may not be apparent to surgeons, can also affect these properties. The supplier of Palacos bone cement with added gentamicin changed in 2005. We carried out a study to examine the mechanical characteristics and antibiotic elution of Schering-Plough Palacos, Heraeus Palacos and Depuy CMW Smartset bone cements.

Both Heraeus Palacos and Smartset bone cements performed significantly better than Schering-Plough Palacos in terms of mechanical characteristics, with and without additional vancomycin (p < 0.001). All cements show a deterioration in flexural strength with increasing addition of vancomycin, albeit staying above ISO minimum levels. Both Heraeus Palacos and Smartset elute significantly more gentamicin cumulatively than Schering-Plough Palacos. Smartset elutes significantly more vancomycin cumulatively than Heraeus Palacos.

The improved antibiotic elution characteristics of Smartset and Heraeus Palacos are not associated with a deterioration in mechanical properties. Although marketed as the ‘original’ Palacos, Heraeus Palacos has significantly altered mechanical and antibiotic elution characteristics compared with the most commonly-used previous version.

We present a series of 114 patients with microbiologically-proven chronically-infected total hip replacement, treated between 1991 and 2004 by a two-stage exchange procedure with antibiotic-loaded cement, but without the use of a prolonged course of antibiotic therapy. The mean follow-up for all patients was 74 months (2 to 175) with all surviving patients having a minimum follow-up of two years. Infection was successfully eradicated in 100 patients (87.7%), a rate which is similar to that reported by others, but where prolonged adjuvant antibiotic therapy has been used. Using the technique described, a prolonged course of systemic antibiotics does not appear to be essential and the high cost of the administration of antibiotics can be avoided.

The use of prolonged courses of parenteral or oral antibiotic therapy in the management of two stage revision of infected total knee arthroplasty is reported by all major series.

We present a series of 59 consecutive patients, all with microbiologically proven deep infection managed at our unit where a prolonged course of antibiotic therapy has not been routinely used. The mean follow-up is 56.4 months (range 24–114 months). Of the 38 patients undergoing a staged exchange, infection was successfully eradicated in 34 patients (89%) with recurrent or persistent infection in 4 (11%). The infection cure rate in our series is similar that reported elsewhere.

A prolonged course of antibiotic therapy does not seem to alter the incidence of recurrent or persistent infection. The costs of antibiotic administration are high, both to the patient and care facility. It may be unnecessary.

All major studies have incorporated the use of prolonged courses of parenteral or oral antibiotic therapy in the management of two-stage revision of an infected total knee arthroplasty. We present a series of 59 consecutive patients, all with microbiologically-proven deep infection of a total knee arthroplasty, in whom a prolonged course of antibiotic therapy was not routinely used. The mean follow-up was 56.4 months (24 to 114).

Of the 38 patients who underwent a staged exchange, infection was successfully eradicated in 34 (89%) but recurrent or persistent infection was present in four (11%). Our rate of cure for infection is similar to that reported elsewhere. We conclude that a prolonged course of antibiotic therapy seems not to alter the incidence of recurrent or persistent infection. The costs of the administration of antibiotics are high and such a regime may be unnecessary.

We describe our medium-term results for the management of chronic osteomyelitis in long bones using the Lautenbach procedure. Seventeen consecutive patients (18 segments) were treated prospectively. Osteomyelitis had been present for a mean of 12.5 years (1 to 31). A discharging sinus was present in all cases. Nine of the associated fractures had failed to unite and a further two needed correction of malunion. The Lautenbach procedure involves debridement, intramedullary reaming and the insertion of double-lumen tubes to establish both a local antibiotic delivery system and cavity analysis for volume and culture. The end-point of treatment is when the irrigate produces three consecutive clear cultures with improvement in the blood indices and obliteration of the cavity volume.

The mean length of treatment was 27 days (14 to 48). One patient required a second procedure and another local debridement for recurrence of the infection. Two patients had Papineau grafting because of cortical defects. All the patients have subsequently remained free from infection. After treatment 11 had internal or external fixation for treatment of non- or malunion or a joint replacement, including two successful limb-lengthening procedures. Two further patients, while cured of infection, underwent amputation for other reasons. The mean length of follow-up was 75 months.

This procedure allows precise control over the osteomyelitis until objective assessment suggests that infection has been cleared and the cavity obliterated.

We recommend this procedure for long-standing complex cases in which basic techniques using debridement and antibiotics have failed.

The incidence of infection after primary arthroplasty is low. However, with the increasing number of arthroplasties being performed the prevalence of infection is increasing. The pattern of infecting organisms following total joint arthroplasty has changed and gentamicin resistant organisms are becoming increasingly common. Vancomycin added to bone a cement carrier can, with adequate surgical debridement be very effective in the eradication of established resistant infection. We report the results of its use in 33 patients with 26 infected hip and 7 infected knee arthroplasies. 32 patients remain clinically and radiologically free of infection after a mean follow-up of 67 months. There was one recurrence of infection and there were three positive second stage cultures of uncertain significance. Vancomycin is potentially a very useful tool in the management of deep infection following arthroplasty surgery.

Although the incidence of infection associated with hip and knee prostheses is low, with the increasing number of arthroplasties being carried out, the total number of such cases is increasing. The pattern of infecting organisms after total joint arthroplasty has changed and gentamicin-resistant organisms are becoming increasingly common. In conjunction with surgical debridement, vancomycin added to a bone-cement carrier can be very effective in the treatment of infection caused by such organisms.

We report the results of its use in proven deep infection in 26 hip and seven knee arthroplasties. After a mean follow-up of 67 months, 32 patients remained clinically and radiologically free from infection. There was one recurrence and positive second-stage cultures of uncertain significance in three other patients. Vancomycin is potentially very useful in the management of deep infection after arthroplasty.

We report two cases of fungal infection of prosthetic joints which were successfully treated by the incorporation of fluconazole into polymethylmethacrylate beads inserted at the time of debridement.

We reviewed a series of 91 patients with deep infection of a cemented total hip arthroplasty caused by coagulase-negative staphylococci (C-NS). Of these, 72 were treated by one-stage exchange arthroplasty with a failure rate of 13% due to recurrence of infection. The other 19 patients have started or completed treatment by a two-stage exchange without failure to date. In 27 of the 91 patients multiple strains of C-NS were discovered, many being resistant to previously used antibiotics. The use of gentamicin-containing cement in the primary arthroplasty was significantly associated with the emergence of gentamicin-resistant C-NS in subsequent deep infection. Bacteriological diagnosis of such infections must take into consideration the possibility that multiple strains of the organism are involved.