Background Optimal treatment of prosthetic joint infection and chronic osteomyelitis consists of surgical removal of biofilm-embedded bacteria, followed by a 6–12 week course of antimicrobial therapy. However, when optimal surgery is not feasible, oral prolonged suppressive antibiotic therapy (PSAT) is recommended to prevent prosthesis loosening and/or relapse of infection. Since 2010, we have used infection salvage therapy using off-label subcutaneous (sc) injection of a β-lactam as PSAT for patients in whom oral PSAT is not possible. Methods A single-centre prospective cohort study (2010–18) reporting treatment modalities, efficacy and safety in all patients receiving sc PSAT. NCT03403608. Results The 10 included patients (median age 79 years) had polymicrobial (n = 5) or MDR bacterial (n = 4) prosthetic joint infection (knee, n = 4; hip, n = 3) or chronic osteomyelitis (n = 3). After initial intensive therapy, seven patients received ertapenem, three patients received ceftriaxone and one patient received ceftazidime by sc injection (one patient received 8 days of ceftriaxone before receiving ertapenem). In one patient, sc PSAT failed with recurrent signs of infection under treatment. In three patients, sc PSAT had to be discontinued due to side effects; in only one of these was the sc route implicated (skin necrosis following direct sc injection and not gravity infusion). Median treatment duration was 433 days. In six patients, sc PSAT was successful with favourable outcome at the time of writing. Interestingly, three patients with MDR bacterial carriage at baseline lost this under PSAT during follow-up. Conclusions As salvage therapy, sc PSAT delivered by gravity infusion is a safe and interesting alternative when an optimal surgical strategy is not feasible and no oral treatment is available.

Purpose The purpose of this study was to report the long-term outcomes of a continuous series of patients who underwent simultaneous anterior cruciate ligament (ACL) reconstruction and opening wedge high tibial osteotomy (HTO) for varusrelated early medial tibio-femoral osteoarthritis. It was hypothesized that this combined surgery sustainably allowed return to sport with efficient clinical and radiological results. Methods From 1995 to 2015, all combined ACL reconstruction (bone-patellar tendon-bone graft) and opening wedge HTO for anterior laxity and early medial arthritis were included. Clinical evaluation at final follow-up used Tegner activity score, Lysholm score, subjective and objective IKDC scores. Radiologic evaluation consisted in full-length, standing, hip-to-ankle X-rays, monopodal weight-bearing X-rays and skyline views. AP laxity assessment used Telos™ at 150 N load. Student's t test was performed for matched parametric data, Wilcoxon for nonparametric variables and Friedman test was used to compare small cohorts, with p < 0.05. Results 35 Patients (36 knees) were reviewed with a mean follow-up of 10 ± 5.2 years. The mean age at surgery was 39 ± 9. At final follow-up 28 patients (80%) returned to sport (IKDC ≥ B): 11 patients (31%) returned to sport at the same level and 6 (17%) to competitive sports. Mean subjective IKDC and Lysholm scores were 71.8 ± 14.9 and 82 ± 14.1, respectively. The mean decrease of the Tegner activity level from preinjury state to follow-up was 0.8 (p < 0.01). Mean side-to-side difference in anterior tibial translation was 5.1 ± 3.8 mm. Three patients were considered as failures. The mean preoperative mechanical axis was 4.2° ± 2.6° varus and 0.8° ± 2.7° valgus at follow-up. Osteoarthritis progression for medial, lateral, and femoropatellar compartments was recorded for 12 (33%, p < 0.05), 6 (17%, p < 0.001), and 8 (22%, p < 0.05) knees, respectively. No femoro-tibial osteoarthritis progression was observed in 22 knees (61%). Conclusions Combined ACL reconstruction and opening wedge HTO allowed sustainable stabilization of the knee at 10-year follow-up. However, return to sport at the same level was possible just for one-third of patients, with femoro-tibial osteoarthritis progression in 39% of cases. Level of evidence III.

Bacteriophages are viruses that specifically target bacteria. They are considered to have a high potential in patients with prosthetic joint infection (PJI), as they have a synergistic anti-biofilm activity with antibiotics. We report here the case of an 88-year-old man (63 kg) with relapsing Pseudomonas aeruginosa prosthetic knee infection. The patient had severe alteration of the general status and was bedridden with congestive heart failure. As prosthesis explantation and/or exchange was not feasible, we proposed to this patient the use of phage therapy to try to control the disease in accordance with the local ethics committee and the French National Agency for Medicines and Health Products Safety (ANSM). Three phages, targeting P. aeruginosa, were selected based on their lytic activity on the patient's strain (phagogram). Hospital pharmacist mixed extemporaneously the active phages (initial concentration 1 ml of 1 × 1010 PFU/ml for each phage) to obtain a cocktail of phages in a suspension form (final dilution 1 × 109 PFU/ml for both phages). Conventional arthroscopy was performed and 30 cc of the magistral preparation was injected through the arthroscope (PhagoDAIR procedure). The patient received intravenous ceftazidime and then oral ciprofloxacin as suppressive antimicrobial therapy. Under this treatment, the patient rapidly improved with disappearance of signs of heart failure and pain of the left knee. During the follow-up of 1 year, the local status of the left knee was normal, and its motion and walking were unpainful. The present case suggests that the PhagoDAIR procedure by arthroscopy has the potential to be used as salvage therapy for patients with P. aeruginosa relapsing PJI, in combination with suppressive antimicrobial therapy. A Phase II clinical study deserves to be performed to confirm this hypothesis.

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