Clinical features and outcome of bone and joint infections with streptococcal involvement: 5-year experience of interregional reference centres in the south of France.

Streptococcal bone and joint infections are less common than staphylococcal cases. Few studies have reported the cases with well-identified Streptococcus species. Their clinical features and prognosis are not clearly known to date. Moreover, no treatment regimen has yet been clarified. We reviewed the streptococcal bone and joint infection cases managed in our centres from January 2009 to December 2013. We described the epidemiology, clinical and microbiologic characteristics, treatment approach and outcome. Among the 93 cases, 83% of patients were men with a median age of 60 years, and 90% of patients had comorbidities or risk factors. Bacteraemia occurred in 14% of cases. Serious complications occurred in six patients, including severe sepsis (two cases) and infective endocarditis (two cases). Orthopaedic device infections were observed in 35% of cases, including 17 patients with internal osteosynthesis device infection, 14 with prosthetic joint infection and three with vertebral osteosynthesis device infection. The median time between orthopaedic device implantation and onset of infection was 447 days. Fourteen species of Streptococcus were identified, including 97 isolates using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and three isolates using molecular identification. The five most represented species included S. agalactiae (37%), S. dysgalactiae (12%), S. anginosus (11%), S. constellatus (10%) and S. pneumoniae (9%). Streptococci isolates were susceptible to amoxicillin, with the exception of one S. mitis isolate. Remission 1 year after the end of treatment was recorded in 83%. One patient died of infection; eight patients had infections that failed to respond to treatment; and seven patients experienced relapse. Twenty patients (22%) had an unfavourable functional outcome, including 19 amputations and one arthrodesis. Five significant prognostic factors associated with an unfavourable clinical outcome were identified, including peripheral neuropathy (p 0.009), peripheral arterial disease (p 0.019), diabetes mellitus (p 0.031), location in the femur (p 0.0036), location in the foot (p 0.0475), osteitis without an orthopaedic device (p 0.041) and infection caused by S. dysgalactiae (p 0.020). The rate of poor outcomes remains high despite the low number of Streptococcus isolates resistant to antibiotics. Some prognostic factors, such as the presence of S. dysgalactiae, are associated with an unfavourable clinical outcome. Antibiotic regimens of streptococcal bone and joint infections are not standardized and need to be further investigated.

Staphylococcus caprae bone and joint infections: a re-emerging infection?

Staphylococcus caprae has been recently classified as a human pathogen, but the incidence of S. caprae in human bone and joint infections (BJIs) is under-reported. In this study, we report 25 cases of S. caprae BJI, and we review the 31 cases published in the literature. Molecular techniques and matrix-assisted laser desorption ionization time-of-flight mass spectrometry improved the identification of clinically relevant S. caprae strains. In this study, 96% of S. caprae BJIs were localized to the lower limbs, and 88% of the cases involved orthopaedic device infections. S. caprae joint prosthesis infections (JPIs), internal osteosynthesis device infections (I-ODIs) and BJIs without orthopaedic device infections were recorded in 60%, 28% and 12% of cases, respectively. Ten (40%) S. caprae BJIs were polymicrobial infections. These infections were associated with past histories of malignancy (p 0.024). Of the 14 bacterial species related to S. caprae BJI, 57% were staphylococci. I-ODIs were significantly associated with polymicrobial infections (p 0.0068), unlike JPIs, which were monomicrobial infections (p 0.0344). Treatment with rifampicin and fluoroquinolone was recorded in 40% of cases. Surgical treatment was performed in 76% of cases, e.g. prosthesis removal (36%), osteosynthesis device removal (24%), and surgical debridement (16%). Thirty per cent of cases were not treated. Relapses were observed mainly in the patients treated by surgical debridement only (p 0.033). In summary, S. caprae BJI is an underestimated hospital-acquired emerging infection. S. caprae BJI is correlated with infections in orthopaedic devices, which must be removed to control the infection.

Bone and joint infections due to anaerobic bacteria: an analysis of 61 cases and review of the literature.

The diagnosis of anaerobic bone and joint infections (BJI) were underestimated before the advent of molecular identification and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). We report 61 cases of anaerobic infections based on our 4-year experience with the management of BJI. A total of 75% of cases were post-surgical infections, associated with osteosynthesis devices (65%). Early infections occurred in 27% of cases, delayed infections in 17.5% of cases, and late infections in 55% of cases. We recorded 36 species of 93 anaerobic strains using MALDI-TOF MS (91) and molecular methods (2). We identified 20 strains of Propionibacterium acnes, 13 of Finegoldia magna, six of Peptoniphilus asaccharolyticus, and six of P. harei. Polymicrobial infections occurred in 50 cases. Surgical treatment was performed in 93.5% of cases. The antibiotic treatments included amoxicillin (30%), amoxicillin-clavulanic acid (16%), metronidazole (30%), and clindamycin (26%). Hyperbaric oxygen therapy was used in 17 cases (28%). The relapse rate (27%) was associated with lower limbs localization (p = 0.001). P. acnes BJI was associated with shoulder (p = 0.019), vertebra (p = 0.021), and head flap localization (p = 0.011), and none of these cases relapsed (p = 0.007). F. magna BJI was associated with ankle localization (p = 0.014). Anaerobic BJI is typically considered as a post-surgical polymicrobial infection, and the management of this infection combines surgical and medical treatments. MALDI-TOF MS and molecular identification have improved diagnosis. Thus, physicians should be aware of the polymicrobial nature of anaerobic BJI to establish immediate broad-spectrum antibiotic treatment during the post-surgical period until accurate microbiological results have been obtained.

Traumatic inter-condylar dislocation of the patella: report of two cases.

Traumatic patellar dislocation usually occurs in the lateral direction. In a few cases, however, the patella rotates around its horizontal axis and becomes wedged between the femoral condyles. We report two cases of traumatic inter-condylar patellar dislocation that required surgical management.