R. M. Kerry

The use of vancomycin-impregnated cement beads in the management of infection of prosthetic joints

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.

Irradiated allograft bone for acetabular revision surgery: RESULTS AT A MEAN OF FIVE YEARS

We report the results of the revision of 123 acetabular components for aseptic loosening treated by impaction bone grafting using frozen, morsellised, irradiated femoral heads and cemented sockets. This is the first large series using this technique to be reported. A survivorship of 88% with revision as the end-point after a mean of five years is comparable with that of other series.

Bone remodelling around a cemented polyethylene cup: A LONGITUDINAL DENSITOMETRY STUDY

The aims of this study were to examine the repeatability of measurements of bone mineral density (BMD) around a cemented polyethylene Charnley acetabular component using dual-energy x-ray absorptiometry and to determine the longitudinal pattern of change in BMD during the first 24 months after surgery. The precision of measurements of BMD in 19 subjects ranged from 7.7% to 10.8% between regions, using a four-region-of-interest model. A longitudinal study of 27 patients demonstrated a transient decrease in net pelvic BMD during the first 12 months, which recovered to baseline at 24 months. The BMD in the region medial to the dome of the component reduced by between 7% and 10% during the first three months, but recovered to approximately baseline values by two years. Changes in BMD in the pelvis around cemented acetabular components may be measured using dual-energy x-ray absorptiometry. Bone loss after insertion of a cemented Charnley acetabular component is small, transient and occurs mainly at the medial wall of the acetabulum. After two years, bone mass returns to baseline values, with a pattern suggesting a uniform transmission of load to the acetabulum.

Fluconazole-impregnated beads in the management of fungal infection of prosthetic joints

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.

Mid- to long-term results of irradiated allograft in acetabular reconstruction: A FOLLOW-UP REPORT

Between 1990 and 2000, 123 hips in 110 patients were reconstructed for aseptic loosening using impaction bone grafting with frozen, irradiated, morsellised femoral heads and cemented acetabular components. This series was reported previously at a mean follow-up of five years. We have extended this follow-up and now describe the outcome of 86 hips in 74 patients at a mean of ten years. There have been 19 revisions, comprising nine for infection, seven for aseptic loosening and three for dislocation. In surviving acetabular reconstructions, union of the graft had occurred in 64 of 67 hips (95.5%). Survival analysis for all indications at ten years was 83.3% (95% confidence interval (CI) 68 to 89) and 71.3% (95% CI 58 to 84) at 15 years. Acetabular reconstruction using irradiated allograft and a cemented acetabular component is an effective method of reconstruction, providing results in the medium- to long-term comparable with those of reported series where non-irradiated freshly-frozen bone was used.

The survival of support rings in complex acetabular revision surgery

Between 1980 and 2000, 63 support rings were used in the management of acetabular deficiency in a series of 60 patients, with a mean follow-up of 8.75 years (2 months to 23.8 years). There was a minimum five-year follow-up for successful reconstructions. The indication for revision surgery was aseptic loosening in 30 cases and infection in 33. All cases were Paprosky III defects; IIIA in 33 patients (52.4%) and IIIB in 30 (47.6%), including four with pelvic dissociation. A total of 26 patients (43.3%) have died since surgery, and 34 (56.7%) remain under clinical review. With acetabular revision for infection or aseptic loosening as the definition of failure, we report success in 53 (84%) of the reconstructions. A total of 12 failures (19%) required further surgery, four (6.3%) for aseptic loosening of the acetabular construct, six (9.5%) for recurrent infection and two (3.2%) for recurrent dislocation requiring captive components. Complications, seen in 11 patients (18.3%), included six femoral or sciatic neuropraxias which all resolved, one grade III heterotopic ossification, one on-table acetabular revision for instability, and three early post-operative dislocations managed by manipulation under anaesthesia, with no further instability. We recommend support rings and morcellised bone graft for significant acetabular bone deficiency that cannot be reconstructed using mesh.

Treatment without long courses of systemic antibiotics

We manage prosthetic joint infection without systemic antibiotics or prolonged hospital admission (or intravenous antibiotics via outpatient intravenous services).1 We target antibiotic treatment to organisms isolated from either a diagnostic aspirate or joint washout (in the case of early infection). At the …

Stay Short or Go Long? Can a Standard Cemented Femoral Prosthesis Be Used at Second-Stage Total Hip Arthroplasty Revision for Infection Following an Extended Trochanteric Osteotomy?

BACKGROUND The aim of this study was to review the results of the use of a cemented, standard length, taper-slip femoral component at second stage following an extended trochanteric osteotomy (ETO). METHODS We reviewed prospectively collected data from the hospital arthroplasty database, identifying and reviewing all patients who had undergone an ETO at first-stage revision for infection, who had subsequently undergone second-stage reimplantation. RESULTS Over 17 years, 99 patients underwent 102 2-stage procedures with ETO at first stage, with a mean follow-up of 5.5 years; 70 of 102 patients received a standard prosthesis following ETO union and 32 of 102 patients received a long-stem prosthesis at second stage because of deficiencies in proximal femoral bone stock. There was a significant difference in the Paprosky classification between the 2 groups (P < .0001); 77% of the standard group and 52% of the long-stem group had no complications. A significant complication (infection, fracture, or dislocation) was observed in 12% patients in the standard group and 16% patients in the long-stem group. A number of radiographs were independently reviewed to assess for ETO union and complications and an intraclass correlation of 0.84 (P < .0001) was observed. CONCLUSION A standard femoral prosthesis can be implanted at second stage following ETO union for Paprosky type I and some type II femora. There is no greater risk of complications, and distal bone stock is preserved for potential revision surgery in the future.

Raphael James Kerry

Raphael James Kerry (“Ray”) wrote: “I was born in Nottingham and educated at High Pavement School. The summer of 1939 was highly significant, with a scholarship to read science at University College, Nottingham, as the war started. I became a founder member of Nottingham University Air Squadron, going to a flying school in Florida in peacetime America. “As the war ended I switched to medicine at the …

Letter to the Editor: Aseptic Loosening of Total Hip Arthroplasty: Infection Always Should be Ruled Out

We welcome the study by Parvizi et al. [3] published in the May edition of the journal and the attention it draws to the misdiagnosis of aseptic loosening which may occur if infection is not rigorously excluded. This supports the work of other authors, who have confirmed infection in as much as 13% of cases of presumed aseptic loosening [2]. The methodology of the study however poses some questions. First, the distinction between patients with infection and without infection must be questioned as a large proportion of patients deemed to be correctly diagnosed as having aseptic loosening did not have specimens sent for culture. In patients who did have specimens sent, a minimum of three intraoperative specimens were cultured but this number has been shown to be inadequate [1]. Sending less than five intraoperative specimens is especially likely to be insensitive for the low virulence organisms which are most likely to masquerade as aseptic loosening. There is also the likelihood that a proportion of the patients assigned to Group 1 (prosthetic joint infection) on the grounds of definite prosthetic joint infection at the time of subsequent rerevision actually had infection after their revision surgery rather than representing falsely diagnosed aseptic loosening. Also, in patients assigned to Group 1 on the basis of positive cultures, the number of tissues required to be positive for a diagnosis of infection is not stated. It is recognized that positive cultures from one tissue specimen are likely to represent contamination, again emphasizing the need to send an adequate number of specimens [1]. After arrival at the laboratory, the microbiologic processing of the specimens is not detailed. Variations in processing technique are recognized to greatly impact on the sensitivity and specificity of orthopaedic tissue culture. Correctly diagnosing prosthetic joint infection is a team effort requiring an appropriate number of correctly taken specimens to be rapidly transported to a microbiology laboratory. The specimens need to be processed correctly, avoiding contamination but optimizing the potential for growth of any pathogenic organisms. Important in this regard are the use of broth cultures (and their subsequent terminal subculture at the end of prolonged incubation) in addition to direct cultures and prolongation of incubation to detect slow-growing low virulence organisms [4]. Finally, the organisms grown need to be identified correctly, their significance interpreted, and an appropriate management plan formulated between surgeon and microbiologist. Ideally patients with possible prosthetic joint infections should be under the care of a surgeon with a specialist interest in the field and the diagnostic process facilitated by the use of a microbiology laboratory and reporting microbiologist specializing in orthopaedic infections. By adopting this approach the number of incorrect diagnoses of aseptic loosening can be minimized.