Introduction. We report the results of revision surgery in recurrent infection after anterior cruciate ligament reconstruction (ACLR) consisting of graft canal debridement and the local application of a calcium sulfate bone substitute (CSBS) with the addition of gentamicin and vancomycin in graft canal and infected foci. Materials and methods. Three patients (3 knees) were operated due to a chronic and unsuccessfully treated knee infection after ACLR. Two patients underwent multiple previous revisions (4 and 9, respectively). In all cases, the tibial ACL graft canal and adjacent bone foci were debrided. Post debridement defects in the femur and tibia and the graft tunnel in the tibia were filled with CSBS with an addition of gentamicin and vancomycin. If the absence of the ACL graft was stated, the tibial canal was closed from the joint side with a collagen sponge with gentamicin. Results. After a follow-up of 20 to 26 months, all patients obtained a complete resolution of inflammation and CRP normalization. No side effects related to CSBS were observed. There was no deterioration in the knee function and stability compared to the pre-revision status. Conclusions. CSBS with the addition of gentamicin and vancomycin applied in the graft canal and inflammatory foci in the surrounding cancellous bone proved to be effective and unrelated to complications in chronic infection after ACLR. Level of Evidence: IV (case series).

Introduction Septic arthritis after arthroscopy (SAAA) is a devasting complication which reported frequency varies about 0.04%–5.7%. The aim of the study is to analyze frequency of SAAA at one orthopedic center, risk factors and accuracy of actual prophylactic measures. Materials and Methods A retrospective study (level of evidence: V) includes 794 (665 primary and 129 revision) “clean” arthroscopies performed in the years 2017–2018 with confirmed joint infection during 30 days after operation without the use of non-resorbable implants and up to 1 year after procedures with non-resorbable implants. Demographic and medical data about potential risk factors of SAAA were analyzed: patients age, sex, operated joint, type of procedure, primary or revision procedure, the use of drains, usage of non-absorbable implant, time of surgery, BMI, time lapse from index operation to diagnosis of SAAA, length of hospital stay, causative microorganisms. All operations were performed by eight different but experienced surgeons, in operation theatre with vertical laminar flow with the capacity of 50 air exchanges per hour. The perioperative antibiotic prophylaxis consisted of one preoperative dose 1 g cefazolin in simple arthroscopies, which was prolonged to 24 hours with 3 doses in cases of implantation of non-absorbable implant (55.8% of patients). Results From 794 cases 4 have been infected: 2 after knee arthrolysis, one after ACL reconstruction and one after rotator cuff repair. There were 2 early, with manifestation within 30 days, and 2 late-onset SAAA. Infections occurred in 0.5% of all arthroscopies and in 0.47% of knee arthroscopies alone. Patients age and time of surgery have not been found significantly different in infected and non-infected cases, whereas age and time of surgery have been significantly different in revision and non-revision cases. Conclusions Primarily aseptic arthroscopic procedures performed with respect to actual perioperative preventive measures have a low risk of postoperative septic arthritis. The risk increases with patients age and time of operation, but not significantly.