1 Introduction

The relationship between specialisation and clinical outcomes have been well documented in the orthopaedic literature.^1–7 Evidence suggests that hospitals and clinicians with higher volumes are likely to produce better than average results and that hospitals and individual clinicians performing low numbers of procedures are not likely to produce the best outcomes and therefore not provide best value for financial resources.^5,7 The more complex procedures, therefore, are best performed by surgeons with experience in similar cases to ensure improved patient outcomes. Managing infected hip replacements is challenging and requires experience in advanced arthroplasty techniques and reconstructions. One solution is to limit the complex procedures in district general hospitals to one or two surgeons with subspecialty interest and experience in particular procedures such as managing periprosthetic joint infection (PJI). The Getting it Right First Time (GIRFT) report also highlighted the need for regional networks to be set up for complex orthopaedic procedures to ensure best outcomes.⁸

In our district unit we perform high volume of primary hip and knee arthroplasties. Revision arthroplasties are currently performed by two surgeons. The senior author (NE) has special interest in managing revision arthroplasty and PJI.⁹ We believe having surgeons with subspecialty interest within district general hospital settings provides and maintains the necessary experience to manage complex cases and improves patients’ outcomes.

The choice of single- or two-stage revision for PJI of the hip remains controversial. Surgeons balance multiple factors when pursuing a particular strategy based on patients’ factors, their own skills and expertise, available resources, and the infecting organism. To date, there are no level-I evidence comparing these two approaches. The INFORM trial,¹⁰ (ISRCTN10956306), is the first multicentre randomised controlled trial comparing single-versus two-stage revisions for infected hip arthroplasties and it is currently recruiting patients. The available evidence currently based on observational studies that have assessed re-infection outcomes following the one-stage or two-stage surgical revisions and have reported inconsistent results.^11–13

The aim of this study was to evaluate the clinical outcomes of subspecialist-surgeon's consecutive series of two-stage revision of infected total hip replacements in district general hospital settings.

2 Materials & methods

We included a consecutive series of patients with PJI of the hip who underwent two-stage revision protocol with minimum 2-year follow up. All patients had confirmed PJI based on the international consensus criteria¹⁴ at time of presentation and confirmed infecting organism from deep tissue samples taken at time of first stage revision. Local approval was obtained from the local research and ethical committee. Demographic and operative data were collected. Formal clinical assessment was undertaken for the purposes of this study with both objective and patient reported outcome measures performed at final follow up. We considered infection “controlled” when the following criteria were met: absence of clinical, serologic, and radiographic signs of infection, and no mortality secondary to infection or treatment during the follow up period. This was confirmed at final follow up using the Musculoskeletal Infection Society criteria.^14,15 We considered failure to eradicate infection as recurrence of infection with same or other organisms, need for repeat second stage or excision arthroplasty. Our outcome measures included the Western Ontario and McMaster Universities Osteoarthritis-Hip (WOMAC),¹⁶ Oxford Hip Score (OHS)¹⁷ and the Hip Disability and Osteoarthritis Outcome Score (HOOS).¹⁸

3 Results

We included 29 consecutive patients (13 females, 16 males) with minimum 2-year follow up, average 5 yrs (range 2–9). Average ag at presentation was 63 yrs (range 30–75). The underlying diagnoses prior to primary hip replacements were mostly osteoarthritis (19/29). Nine patients (31%) had previous surgeries prior to their primary hip replacement and six patients (20.7%) reported having wound problems at time of their primary hips. Primary implants were uncemented metal-on-metal (27.6%) (Table 1). Average interval between primary and first-stage was 7.3 yrs (SD 5.7; range 0.5–25 yrs). Most presented with chronic infections (76%) and 5 patients (17%) presented with sepsis (Table 2). Average interval between stages was 3.5 months (2–7 months). One patient presented with profound sepsis required prolonged ITU stay and repeat first stage, reimplantation was delayed for 7 months until medically optimised. Infection eradication rate at final follow up was 96.5% (1 reinfection). Overall complication rate was 13.8% (Table 3). One young patient with hepatitis-C and intravenous drug abuse had failed 2-stage protocol and had recurrence of infection and was treated with excision arthroplasty, patients reported outcome measures were therefore collected for 28 patients. The mean and average scores summarised in Table 4. These scores suggest satisfactory outcomes.

4 Discussion

Two stage revision remains the gold standard for managing PJI around hip replacements. Although high success rate in eradicating infection through a single stage revision have been reported in the literature. Wolf et al.¹³ in their systematic review of 11 two-stage studies (321 patients) and eight one-stage studies (576 patients) reported an increased re-infection rate after one-stage (12.3%) compared to two-stage revision (6.5%) of infected total hip replacements. There was however a higher mortality rate associated with the two-stage compared to one-stage. In another review, Lange et al.,¹¹ of 36 studies of either one-stage revision (375 patients) or two-stage revision (929 patients), reinfection occurred with an estimated absolute risk of 13.1% (95% confidence interval: 10.0%–17.1%) in the one-stage cohort and 10.4% (95% confidence interval: 8.5%–12.7%) in the two-stage cohort. Functional outcomes have not been studied as extensively as reinfection rates. Lenoard et al.¹² in their review assessed functional outcomes and found only small case series studies with small numbers of patients with a trend toward better functional outcomes in single-stage surgery, but this reached significance in only one study. In this study, all patients underwent two-stage revisions. In their cross-sectional study of patient-reported outcome measures following two-stage revision, Polusen et al.¹⁹ reported mean OHS 29.2 (range 25.4–33.0; n = 45). In a systematic review of 12 studies of two-stage revision, the average WOMAC score was 73 (n = 185) patients with a mean follow-up of 69.8 months.²⁰ Most of these studies were small case-series from tertiary centres.

Our success in eradicating infection through two-stage revision protocol and our patient-reported outcome measures indicate that our results are at least comparable to what has been reported in series from tertiary centres.11–13^,19–21

5 Conclusions

We believe that subspecialisation in arthroplasty to manage PJI within orthopaedic departments in district general hospitals has the potential to improve patients’ outcomes. Regional multidisciplinary meetings and networks with specialist tertiary centres provide the support for such local services and tertiary referrals are then made in conjunction with these regional centres.

Conflicts of interest

None to be declared by any of the authors.