Aim

Acute hematogenous periprosthetic joint infection (AHI) is a diagnosis on the rise. The management is challenging and the optimum treatment is not clearly defined. The purpose of this study was to evaluate the characteristics of AHI, and to study risk factors affecting treatment outcome.

Aim

Debridement, antibiotics and implant retention (DAIR) has become the preferred treatment in early prosthetic joint infections (PJI) and acute haematogenous PJI, but the success rates have been varying. The aim of this study was to evaluate the outcome of a high quality DAIR procedure performed according to a consistently applied surgical protocol in early PJI's and acute haematogenous PJI's in hip and knee.

Aim

Prosthetic joint infection (PJI) is a much feared complication to arthroplasty with significant patient morbidity. Rifampin is increasingly used in staphylococcal PJIs treated with debridement and retention of the prosthesis. The evidence supporting rifampin combination therapy in PJIs is limited due to the lack of controlled studies. The aim of this study is to evaluate the effect of adding rifampin to conventional antimicrobial therapy in early staphylococcal PJIs treated with debridement and retention.

Summary Statement

Our data suggest that postoperative component positioning in TKA with PSPG is not consistent with pre-operative software planning. More studies are needed to rule out possible learning curve in this study.

Background: Infection after total hip arthroplasty is a dreaded complication with an incidence of 0,5–1 % after primary interventions. The optimum treatment of deep infection remains controversial. Debridement, retention of the prosthesis and antimicrobial treatment is an attractive option of treatment for early deep infections, but this method has often been reported with poor outcome. If restricting this method to patients with a stable implant, short duration of symptoms and contained soft tissue, the success rate seems to be substantially improved. We report the outcome of early prosthetic joint infections treated with debridement and retention of components in a prospectively recorded 8-year cohort.

Materials and Methods: All elective hip arthroplasties between 1998 and 2005 were prospectively recorded as a part of a quality registration with demographic and clinical data. In the same period, we recorded 39 (24 women) consecutive patients with a mean age of 71 years (range, 32–89) who presented with an early prosthetic joint infection within one month after the index operation. Infection was clinically diagnosed and based on the CDC definition for deep incisional surgical site infection. Medical and surgical treatment were chosen individually by the treating surgeons on the basis of the different clinical settings. The primary outcome measures were clinical, radiographic and laboratory evidence of recurrent infection or revision with isolation of the initial microbial agent. All patients were followed from index operation to final clinical visit in 2008 or death. 11 patients were dead, and a chart review was then done.

Results: Staphylococcus aureus was isolated in 23/39 patients (59%). Coagulase negative staphylococci were isolated in 19 patients (49 %), of which 4 were methicillin-resistant. 15 of the infections were polymicrobial. 37 patients were treated with soft-tissue debridement, retention of the prosthesis and antimicrobial therapy. The mean duration of antimicrobial therapy was 70 days (range, 20–270). The mean duration of days after index operation until initial debridement, was 22 days (range, 11–63). At a mean follow-up of 48 months (range, 9–120), 35/37 patients had no signs of recurrent prosthetic infection. 26 infections (70,3%) were eradicated by debridement alone, 9 after additional surgery. When treated within 3 weeks after index operation, 17/23 infections were eradicated by debridement alone (73,9%).

Conclusions: The data suggests that debridement, retention of the prosthesis and antimicrobial treatment is a reasonable option for treating early prosthetic joint infection after primary hip arthroplasty. Efficacy seems higher with earlier diagnosis and treatment.

Introduction: C-stem is a triple taper polished femoral stem. The rationale for this design is to achieve an evenly distributed proximal loading of the cement mantle. This design is thought to enhance stability of the stem inside the mantle and lead to bone remodelling medially. There is to our knowledge no randomized trial comparing this stem to a well documented stem. We chose to compare it to the best documented stem in the Norwegian arthroplasty register, the Charnley monoblock.

Methods: 70 patients scheduled for total hip replacement were randomized to either C-stem or Charnley monoblock. All received a 22 mm stainless steel head, OGGEE cup and Palacos Cement with Gentamycin. We used a transgluteal approach in all cases. Harris and Oxford hip scores were measured preoperatively and after two years. Standard X-rays were taken postoperatively and after two years. Radiostereometry (RSA) was done postoperatively and after 3,6,12 and 24 months.

Results: There was no significant difference in Harris or Oxford hip scores after two years.

RSA after two years: (table deleted)

Discussion: Polished tapered stems are designed to sink inside the mantle. Our results confirm this theory for the C-stem. The subsidence is comparable to other collarless tapered stems with good long-term survival. For all other migrations/rotations the C-stem is as stable as the Charnley monoblock. This predicts good long-term results for this stem.

Roentgen stereophotogrammetry was used to measure the migration of the centre of the femoral head in 84 cemented Lubinus SP I hip arthroplasties (58 primary operations, 26 revisions). Four to seven years later, seven femoral components had been revised because of painful loosening. These implants showed greater subsidence, medial migration and posterior migration during the first two postoperative years than did the hips which had not been revised. Six months after operation, subsidence of more than 0.33 mm combined with a total migration of more than 0.85 mm predicted an increased risk of subsequent revision; the amount of subsidence at two years was an even better predictor. The probability of revision was greater than 50% if the subsidence at two years was 1.2 mm or more.

We investigated the fixation of fully-threaded cementless acetabular prostheses in 20 patients with osteoarthritis, measuring the migration of the cup using roentgen stereophotogrammetric analysis (RSA). All the cups migrated proximally, 13 moved laterally or medially, and nine moved anteriorly or posteriorly in the first two postoperative years, the average migration being 1.1 to 1.4 mm in either direction. Rotatory movements of up to 5.7 degrees were found in nine of the 13 hips where this analysis could be performed. Movements of cobalt-chrome (12) and titanium alloy (8) cups did not differ significantly. Seventeen of the 20 patients had some pain two years after the operation. The migration of the prostheses indicates that 'osseointegration' had not occurred. The combination of this with persistent pain suggests that the long-term results will be unfavourable.