Christen Ravn

Dr. Christen Ravn


Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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12 January 2023 in Journal of Bone and Joint Infection
Verified
Journal Article
Open access
PDF file
CRChristen Ravn
Christen Ravn
JNJeroen Neyt
Jeroen Neyt
Natividad BenitoNatividad Benito
Natividad Benito
MAMiguel Araújo Abreu
Miguel Araújo Abreu
YAYvonne Achermann
Yvonne Achermann
ASAlex Soriano
Alex Soriano
This clinical guideline is intended for use by orthopedic surgeons and physicians who care for patients with possible or documented septic arthritis of a native joint (SANJO). It includes evidence and opinion-based recommendations for the diagnosis and management of patients with SANJO.

3 April 2023 in Journal of Infection
Verified
Journal Article
Open access
NRNora Renz
Nora Renz
TMTomislav Madjarevic
Tomislav Madjarevic
MFMatteo Ferrari
Matteo Ferrari
RBRoland Becker
Roland Becker
CRChristen Ravn
Christen Ravn
DPDaniel Pérez-Prieto
Daniel Pérez-Prieto
Infection after anterior cruciate ligament reconstruction (ACL-R) is a rare but devastating complication affecting predominantly young and sportive individuals. A timely and correct diagnosis as well as optimized management is paramount to circumvent serious sequelae and compromise in life quality. These recommendations are primarily intended for use by infectious disease specialists and microbiologists, but also orthopedic surgeons and other healthcare professionals who care for patients with infections after ACL-R. They are based on evidence mainly originating from observational studies and opinions of experts in the field, and cover the management of infections after ACL-R with a special focus on etiology, diagnosis, antimicrobial treatment and prevention. Comprehensive recommendations on surgical treatment and rehabilitation are presented separately in a document primarily addressing orthopedic professionals.

20 September 2016 in Acta Orthopaedica
Verified
Journal Article
Open access
CRChristen Ravn
Christen Ravn
UTUlrika Furustrand Tafin
Ulrika Furustrand Tafin
BBBertrand Bétrisey
Bertrand Bétrisey
SOSøren Overgaard
Søren Overgaard
ATAndrej Trampuz
Andrej Trampuz
Background and purpose — Antibiotic treatment of patients before specimen collection reduces the ability to detect organisms by culture. We investigated the suppressive effect of antibiotics on the growth of non-adherent, planktonic, and surface-related biofilm bacteria in vitro by using sonication and microcalorimetry methods. Patients and methods — Biofilms of Staphylococcus aureus, S. epidermidis, Escherichia coli, and Propionibacterium acnes were formed on porous glass beads and exposed for 24 h to antibiotic concentrations from 1 to 1,024 times the minimal inhibitory concentration (MIC) of vancomycin, daptomycin, rifampin, flucloxacillin, or ciprofloxacin. The beads were then sonicated to dislodge biofilm, followed by culture and measurement of growth-related heat flow by microcalorimetry of the resulting sonication fluid. Results — Vancomycin did not inhibit the heat flow of staphylococci and P. acnes at concentrations ≤1,024 μg/mL, whereas flucloxacillin at >128 μg/mL inhibited S. aureus. Daptomycin inhibited heat flow of S. aureus, S. epidermidis, and P. acnes at lower concentrations (32–128 times MIC, p < 0.001). Rifampin showed inconsistent results in staphylococci due to random emergence of resistance, which was observed at concentrations ≤1,024 times MIC (i.e. 8 μg/mL). Ciprofloxacin inhibited heat flow of E. coli at ≥4 times MIC (i.e. ≥ 0.06 μg/mL). Interpretation — Whereas time-dependent antibiotics (i.e. vancomycin and flucloxacillin) showed only weak growth suppression, concentration-dependent drugs (i.e. daptomycin and ciprofloxacin) had a strong suppressive effect on bacterial growth and reduced the ability to detect planktonic and biofilm bacteria. Exposure to rifampin rapidly caused emergence of resistance. Our findings indicate that preoperative administration of antibiotics may have heterogeneous effects on the ability to detect biofilm bacteria.

10 May 2018 in Journal of Orthopaedic Research
Verified
Journal Article
Closed access
PDF file
CRChristen Ravn
Christen Ravn
IFInês S. Ferreira
Inês S. Ferreira
EMElena Maiolo
Elena Maiolo
SOSøren Overgaard
Søren Overgaard
ATAndrej Trampuz
Andrej Trampuz

17 November 2021 in Journal of Clinical Orthopaedics and Trauma
Verified
Journal Article
Open access
PDF file
NJNiels Martin Jensen
Niels Martin Jensen
SSSigne Steenstrup
Signe Steenstrup
CRChristen Ravn
Christen Ravn
HSHagen Schmal
Hagen Schmal
BVBjarke Viberg
Bjarke Viberg
This study aimed to systematically review the current literature on studies using negative pressure wound therapy (NPWT) or dressings following fracture-related infection (FRI) in internal osteosynthesis of the extremity. Articles were analyzed on fracture and wound healing and included when comparing or describing the use of either NPWT or dressings in FRI. We conducted a systematic literature search in four electronic databases: Embase, Medline, the Cochrane Library, and Scopus. The studies were screened by two authors using Covidence.org and evaluated for risk of bias. A total of 8576 records were identified. No articles compared NPWT to dressings. Seven case reports and three case series included a total of 115 patients treated for FRI. Fracture healing was achieved in 21 out of 67 patients treated with NPWT (4 amputations and 46 not described) and all 48 patients in the dressing group (4 patients needed additional sequestrectomy procedures). Five studies did not describe fracture healing. In 57 out of 67 patients treated with NPWT, the wounds were described as healed, closed, or requiring soft tissue reconstruction (4 amputations and six lacking description). The dressing group had complete wound coverage in 18 patients and partial coverage in 30 patients. Studies were generally at high risk of bias because of insufficient descriptions of both patient demographics and outcomes. No studies compared NPWT to dressings, and the existing literature is at high risk of bias. The included studies were of low-level evidence. NPWT can be neither recommended nor advised against to cover infected osteosynthesis.