Aims. Despite recent literature questioning their use, vancomycin and clindamycin often substitute cefazolin as the preoperative antibiotic prophylaxis in primary total knee arthroplasty (TKA), especially in the setting of documented allergy to penicillin. Topical povidone-iodine lavage and vancomycin powder (VIP) are adjuncts that may further broaden antimicrobial coverage, and have shown some promise in recent investigations. The purpose of this study, therefore, is to compare the risk of acute periprosthetic joint infection (PJI) in primary TKA patients who received cefazolin and VIP to those who received a non-cephalosporin alternative and VIP. Methods. This was a retrospective cohort study of 11,550 primary TKAs performed at an orthopaedic hospital between 2013 and 2019. The primary outcome was PJI occurring within 90 days of surgery. Patients were stratified into two groups (cefazolin vs non-cephalosporin) based on their preoperative antibiotic. All patients also received the VIP protocol at wound closure. Bivariate and multiple logistic regression analyses were performed to control for potential confounders and identify the odds ratio of PJI. Results. In all, 10,484 knees (90.8%) received cefazolin, while 1,066 knees (9.2%) received a non-cephalosporin agent (either vancomycin or clindamycin) as preoperative prophylaxis. The rate of PJI in the cefazolin group (0.5%; 48/10,484) was significantly lower than the rate of PJI in the non-cephalosporin group (1.0%; 11/1,066) (p = 0.012). After controlling for confounding variables, the odds ratio (OR) of developing a PJI was increased in the non-cephalosporin cohort compared to the cefazolin cohort (OR 2.389; 1.2 to 4.6); p = 0.01). Conclusion. Despite the use of topical irrigant solutions and addition of local antimicrobial agents, the use of a non-cephalosporin perioperative antibiotic continues to be associated with a greater risk of TKA PJI compared to cefazolin. Strategies that increase the proportion of patients receiving cefazolin rather than non-cephalosporin alternatives must be emphasized. Cite this article: Bone Jt Open 2022;3(1):35–41

Introduction. First generation cephalosporins remain the gold standard perioperative antibiotic for total hip and knee arthroplasty (THA, TKA). However, some patients have documented or self-reported allergies to antibiotics, most commonly penicillin, that result in changes to perioperative antibiotic coverage. Furthermore, patients testing positive for methicillin resistant staphylococcus aureus (MRSA) represent another group where an alternative to cefazolin, typically vancomycin, is often chosen for perioperative prophylaxis. The aims of this study were to 1) characterize the antibiotic choices for perioperative prophylaxis at the time of primary TKA and THA, 2) assess the efficacy of a preoperative antibiotic allergy testing program, and 3) determine rates of periprosthetic joint infection (PJI) based on perioperative antibiotic regimen. Methods. We evaluated all patients undergoing primary TKA or THA at a single academic institution from January 2004-May 2017, yielding a cohort of 29,695 patients. A series of institutional databases were combined to determine which patients underwent antibiotic allergy testing prior to surgery, outcomes from the allergy consultation, perioperative antibiotic management strategy, and survivorship free of infection until final follow-up. Results. Antibiotic allergy testing was performed in 3,411 patients (11.5%) on the basis of a patient provided history of possible penicillin or cephalosporin allergy. Among those tested, 3,310 patients (97.0%) were cleared by the allergist to use cephalosporins in the perioperative period and 2,883 patients (87.1%) eventually received cefazolin. For the entire cohort, 28,174 patients (94.9%) received an operative antibiotic regimen including cefazolin and 1,521 patients (5.1%) received non-cefazolin antibiotics, most commonly vancomycin or clindamycin. Survivorship free of PJI was significantly higher among patients receiving cefazolin compared to non-cefazolin antibiotics with the most rapid divergence occurring within 2 months of surgery (p<0.001) (Figure 1). Survivorship free of PJI in the cefazolin compared to the non-cefazolin groups was 99.40% vs 99.34% at 1 month, 99.11% vs 98.55% at 2 months, 98.83% vs 98.22% at 1 year, and 98.15% vs 96.96% at 10 years (Table 1). Notably, the increased PJI rate observed in the non-cefazolin group was not attributable to high preoperative MRSA prevalence as 0 of the 38 PJIs grew MRSA on culture. The number needed to treat with cefazolin to prevent 1 PJI was 164 patients at 1-year and 84 patients at 10-years. Therefore, potentially 6,098 PJIs could be prevented by 1-year and 11,905 by 10-years in a cohort of 1,000,000 primary TKA and THA patients. Conclusions. This study demonstrates a significantly higher rate of PJI when non-cefazolin antibiotics are used for prophylaxis during primary TKA and THA, which is likely attributable to the superior spectrum of coverage for common PJI organisms compared to vancomycin or clindamycin. This is supported by the increased rate of non-MRSA PJI observed in the non-cefazolin cohort. Furthermore, cefazolin has been shown to act synergistically with vancomycin against MRSA. This work highlights the positive impact of a formal preoperative antibiotic allergy testing program to increase cefazolin usage. Also, surgeons may consider using cefazolin as a dual agent in the case of known MRSA colonization, whenever possible for PJI prophylaxis during TKA and THA. For any figures or tables, please contact authors directly

Aims

This study compared patient-reported outcomes of three total knee arthroplasty (TKA) designs from one manufacturer: one cruciate-retaining (CR) design, and two cruciate-sacrificing designs, anterior-stabilized (AS) and posterior-stabilized (PS).

Aims

The results of irrigation and debridement with component retention (IDCR) in the treatment of acutely infected total knee arthroplasties (TKAs) have been variable. The aim of this study was to assess the outcome after IDCR when combined with chronic antibiotic suppression. We also evaluated survivorship free from subsequent infection, removal of the components, and death, as well as the risk factors for failure.

Aims

To present our experience of using a combination of intra-articular osteotomy and external fixation to treat different deformities of the knee.

Although it is clear that opening-wedge high tibial osteotomy (HTO) changes alignment in the coronal plane, which is its objective, it is not clear how this procedure affects knee kinematics throughout the range of joint movement and in other planes.

Our research question was: how does opening-wedge HTO change three-dimensional tibiofemoral and patellofemoral kinematics in loaded flexion in patients with varus deformity?Three-dimensional kinematics were assessed over 0° to 60° of loaded flexion using an MRI method before and after opening-wedge HTO in a cohort of 13 men (14 knees). Results obtained from an iterative statistical model found that at six and 12 months after operation, opening-wedge HTO caused increased anterior translation of the tibia (mean 2.6 mm, p <  0.001), decreased proximal translation of the patella (mean –2.2 mm, p <  0.001), decreased patellar spin (mean –1.4°, p < 0.05), increased patellar tilt (mean 2.2°, p < 0.05) and changed three other parameters. The mean Western Ontario and McMaster Universities Arthritis Index improved significantly (p < 0.001) from 49.6 (standard deviation (sd) 16.4) pre-operatively to a mean of 28.2 (sd 16.6) at six months and a mean of 22.5 (sd 14.4) at 12 months.

The three-dimensional kinematic changes found may be important in explaining inconsistency in clinical outcomes, and suggest that measures in addition to coronal plane alignment should be considered.

Cite this article: Bone Joint J 2014; 96-B:1214–21.