Open debridement, irrigation with implant retention and antibiotic treatment (DAIR) is an accepted approach for early prosthetic joint infections (PJI). Our aim was to design a score to predict patients with a higher risk of failure.

From 1999 to 2014 early (<90 days) PJIs without signs of loosening of the prosthesis were treated with DAIR and were prospectively collected and retrospectively reviewed. The primary end-point was early failure defined as: 1) the need of an unscheduled surgery, 2) death-related infection within the first 60 days after debridement or 3) the need for suppressive antibiotic treatment. A score was built-up according to the logistic regression coefficients of variables available before debridement.

A total of 222 patients met the inclusion criteria. The most frequently isolated microorganisms were coagulase-negative staphylococci (95 cases, 42.8%) and Staphylococcus aureus (81 cases, 36.5%). Fifty-two (23.4%) cases failed. Independent predictors of failure were: chronic renal failure (OR:5.92, 95%CI:1.47–23.85), liver cirrhosis (OR:4.46, 95%CI:1.15–17.24), revision surgery (OR:4.34, 95%CI:1.34–14.04) or femoral neck fracture (OR:4.39, 95%CI:1.16–16.62) compared to primary arthroplasty, CRP >11.5 mg/dL (OR:12.308, 95%CI:4.56–33.19), cemented prosthesis (OR:8.71, 95%CI:1.95–38.97) and when all intraoperative cultures were positive (OR:6.30, 95%CI:1.84–21.53). Furthermore, CRP showed a direct relationship with the percentage of positive cultures (Linear equation, R2=0,046, P=0.002) and an inverse association with the time between the debridement and failure (Logarithmic equation, R2=0.179, P=0.003). A score for predicting the risk of failure was done using pre-operative factors (KLIC-score, figure 1) and it ranged between 0–9.5 points. Patients with a score ≤2, >2–3.5, 4–5, >5–6.5 and ≥7 had a failure rate of 4.5%, 19.4%, 55%, 71.4% and 100%, respectively.

The KLIC-score was highly predictive of early failure after debridement. In the future, it would be necessary to validate our score using cohorts from other institutions.

Early prosthetic joint infections (PJI) are managed with debridement, implant retention and antibiotics (DAIR). Our aim was to evaluate risk factors for failure after stopping antibiotic treatment.

From 1999 to 2013 early PJIs managed with DAIR were prospectively collected and retrospectively reviewed. The main variables potentially associated with outcome were gathered and the minimum follow-up was 2 years. Primary endpoint was implant removal or the need of reintroducing antibiotic treatment due to failure.

A total of 143 patients met the inclusion criteria. The failure rate after a median (IQR) duration of oral antibiotic treatment of 69 (45–95) days was 11.8%. In 92 cases PJI was due to gram-positive (GP) microorganisms, in 21 due to gram-negatives (GN) and 30 had a polymicrobial infection. In GP infections, combination of rifampin with linezolid, cotrimoxazole or clindamycin was associated with a higher failure rate (27.8%, P=0.026) in comparison to patients receiving a combination of rifampin with levofloxacin, ciprofloxacin or amoxicillin (8.3%) or monotherapy with linezolid or cotrimoxazole (0%) (Figure 1). Among patients with a GN infection, the use of fluoroquinolones was associated with a lower failure rate (7.1% vs 37.5%, P=0.044). Duration of antibiotic treatment was not associated with failure.

The only factor associated with failure was the oral antibiotic selection, but not the duration of treatment. Linezolid, cotrimoxazole and clindamycin but not levofloxacin serum concentrations are reduced by rifampin; a fact that could explain our findings. Further studies monitoring serum concentration could help to improve the efficacy of these antibiotics when combining with rifampin.

Stored red blood cells (RBCs) undergo a variety of changes that impair their post-transfusion viability, but the detrimental effect of such lesion at the clinical level is a matter of debate (1) and there is no data about the incidence of postoperative infection, a complication frequently associated with transfusion of stored RBCs (2).

We reviewed 9906 patients who underwent a primary or revision arthroplasty between January 2000 and December 2012. Of these, 1153 (11.6%) received transfusion during surgery or within the first 6h after surgery (early transfusion, ET) and 920 (9.3%) received transfusion only between 24 and 96 hours after surgery (late transfusion, LT). Primary end-point was prosthetic joint infection (PJI) within the first year. Demographics, joint, type of surgery, duration of surgery, number and length of storage of transfused RBCs were collected. Ethical Committee approved the study.

The median age was 74.9 (IQR:68.3–80.1) years and 1546 (74.6%) were female. There were 914 (44.1%) hip and 1117 (53.9%) knee arthroplasties and 428 (20.6%) were revision surgeries. The median duration of surgery was 105 (IQR:80–145) minutes. A total of 100 (4.8%) patients had a PJI. Figure 1 shows the PJI rate according to the number of RBC units transfused and the proportion of such units that had been stored for more than 14 days, both in the ET-group (Fig. 1A) and the LT-group (Fig. 1B). In the ET-group, the fact that >50% of transfused RBCs had been stored >14 days was an independent predictor of PJI (OR:2.50, 95%CI:1.44–4.33, Hosmer-Lemeshow test P=0.972).

Stored RBC occlude the microcirculation (1), thereby precluding a good oxygenation of the surgical wound and the arrival of leukocytes and prophylactic antibiotics. Both factors are involved in the progression from wound bacterial contamination to wound infection and are particularly operative in the few hours following surgery (5). It is biologically plausible that transfusion of old RBC in this early, critical period results in more wound infections as compared to RBCs transfused later.

In primary total knee arthroplasty (TKA) performed under ischemia the antibiotic prophylaxis is administered 15’ before inflating the tourniquet. The infection rate in TKA is higher than in hip arthroplasty. We hypothesise that ischemia could impair the efficacy of the antibiotic. The objective of our study was to compare the effectiveness of two schedules of antibiotic administration.

We conducted a randomised and a double blind study. Patients were assigned to receive placebo 15’ before inflating tourniquet and cefuroxim 1.5 g 10’ before releasing the tourniquet (experimental arm) or cefuroxim 1.5 g 15’ before inflating tourniquet and placebo 15’ before releasing tourniquet (standard arm). In both arms cefuroxime 1.5 g was administered 6 hours after finishing surgery. The variables gathered were: age, sex, indication for TKA, co-morbidity, ASA score, duration of the operation, number of blood transfusions, days of hospitalisation and number of surgical site infections after 3 months of surgery. Categorical variables were compared using the χ² test or the Fisher exact test and quantitative variables using Student-t test.

Nine hundred and eight patients were randomised and 466 and 442 patients were allocated to experimental and standard arms respectively. Both groups were similar and there were no differences in deep and superficial infection rates, 1.39% and 4.18% for experimental arm and 3.39% and 3.17% for standard arm (p> 0.05). The experimental arm had a lower global and deep infection rate than the standard arm when the length of surgery was lower than the 75th percentile (global: 4.03 vs 7.93%, p=0.04, deep: 1.72% vs 4.44%, p=0.07).

The administration of antibiotic prophylaxis 10’ before releasing the tourniquet decreases the surgical site infection rate when the duration of surgery is lower than the 75th percentile.

Introduction and Objectives: Periprosthetic fractures present some difficult problems: the inability to use intramedullary implants, difficulty in inserting screws (since the cavity is occupied), bone fragility, great mechanical demands, elderly patients, and associated conditions. We have used two osteosynthesis reinforcement techniques in these cases: massive intramedullary cementation and implantation of bone allograph counterplates. Both techniques give a simple solution for complex peri-prosthetic fractures.

Materials and Methods: We used this technique to treat 9 periprosthetic fractures of the femur between 1999 and 2003. In 3 cases, massive intramedullary cementation was used (Johansson type III, distal to the prosthetic stem) and in 6 cases a bone allograft counterplate (Johansson type II, around the prosthesis), associated with the stem replacement in 2 cases. Allografts came from the Tissue Bank of the Institut Clinic de l’Aparell Locomotor (ICAL). There were 7 females and 2 males, with an average age of 76 years (range: 66–83). Average follow-up time was 14 months (range: 6 months to 3.5 years).

Results: In 8 of 9 cases (89%), fracture consolidation was achieved in 3.5 months, with patients regaining the same ability to walk as before the injury. In one case with intramedullary cementation, non-union developed with breakage of the plate at 10 months post-intervention. This case was treated with compression osteosynthesis with a new plate and bone allograft counterplate, and final outcome was satisfactory (consolidation at 4 months) with the patient walking with full weight bearing without crutches.

Discussion and Conclusions: We believe both techniques are useful in the resolution of periprosthetic fractures of the femur over porous bone. However, a very precise surgical technique is necessary, as well as respect for the classical principles of osteosynthesis: fracture fixation with anatomic reduction, interfragmentary compression, and maximum care afforded soft tissue.