Survival analysis of one-stage exchange of infected unicompartmental knee arthroplasty: a single-center study with minimum 3 years follow-up.

PURPOSE: The rates of unicompartmental knee arthroplasty (UKA) are increasing yet little data exists regarding management of periprosthetic joint infections (PJI) after UKA, particularly utilizing one-stage revision. The aim of this study was to determine the septic and all-cause revision-free survival of UKA PJIs treated with one-stage revision, as well as functional outcomes and risk factors for failure. METHODS: A retrospective review of one-stage septic revisions with a hinged or rotating hinged implant between 2000 and 2015 at a single institution was performed. Results of 15 patients with a minimum of 3-year follow-up (mean = 93 months; range 37-217) were evaluated by means of infection control, survivorship, patient reported functional score and possible causal factors for a re-revision. Kaplan-Meier curves and Cox regression analysis were used. RESULTS: After a mean of 8 years of follow-up infection control rate was 93.3%, the survivorship free of any reoperation, including both septic and aseptic causes, was 80% at 5 years and 64.2% at ten years and average Lysholm score was 72.7 ± 21.3 (33-100). CONCLUSION: One-stage revision for PJI of UKA using a hinged knee design has excellent infection-free survival at mid to long-term follow-up. Likewise, patient reported functional outcomes are promising. However, one-third of patients required aseptic reoperation and aseptic loosening was the dominant etiology.

Accident Mechanisms and Injury Patterns in E-Scooter Users­A Retrospective Analysis and Comparison With Cyclists.

BACKGROUND: E-scooter sharing systems were initiated in Hamburg in June 2019. The number of persons injured in Hamburg in e-scooter accidents rose thereafter. The goal of this study was to determine the typical accident mechanisms and injury patterns after e-scooter accidents in Germany, and to compare these with bicycle accidents. METHODS: In a retrospective study, accidents with e-scooters and bicycles that occurred from June 2019 to June 2020 were registered and analyzed with respect to demography, accident mechanisms, diagnostics, patterns of injury, emergency medical care, operations, and inpatient hospitalizations. RESULTS: 89 persons sustained e-scooter accidents (mean age 33.9 years, standard deviation [SD] 14 years); 435 persons who sustained bicycle accidents (mean age 42.5 years, SD 17 years) served as a comparison group. E-scooter accidents more commonly occurred at night (37% versus 14%), and 28% of the persons who sustained them were under the influence of alcohol (cyclists: 6%). 54% of the injured e-scooter riders suffered trauma to the head or face; 14% had a severe head injury and 16% had a severe facial injury. Fractures of the upper limbs were more common than fractures of the lower limbs (18% versus 6%). On initial assessment in the emergency room, injured cyclists were more frequently classified as needing immediate treatment than injured e-scooter riders (7% versus 1%). CONCLUSION: The head, face, and upper limbs are the most commonly affected parts of the body in e-scooter accidents. Compared to bicycle accidents, e-scooter accidents more commonly occur on weekends and in association with alcohol. From a medical point of view, abstaining from alcohol consumption and wearing a helmet when using an e-scooter is strongly recommended.

Do patients with von Willebrand disease exhibit higher blood loss and revision rates in hip and knee arthroplasty? A case-control study.

BACKGROUND: The aim of the study was to compare the perioperative blood loss, need for transfusion and one-year revision rates in patients undergoing hip and knee arthroplasty who also have a diagnosis of von Willebrand disease (VWD) with a matched control group. METHODS: A retrospective single-centre case-control study was conducted. Fifty-eight patients with VWD and 116 controls (1:2 match) who were operated for primary or revision hip and knee arthroplasty at our hospital were included. Blood loss, haemoglobin (Hb)-drop, need for blood transfusion, intraoperative complications and revision rates within one year were noted in all cases. Outcome measures for subgroups of the primary hip, primary knee, revision hip and revision knee procedures, were also analysed. RESULTS: The mean perioperative Hb-drop was 3.47 (±1.27) g/dL and blood loss was 293 (±97) ml for the VWD group while Hb-drop was 2.85 (±1.21) g/dL and blood loss was 232 (±105) mL for the control group (P < .001). There were no significant increased transfusion rates (P = .264) and revision rates in the VWD group (P = .634). Patients having primary hip surgery had significantly higher Hb-drop (3.68 ± 1.25 g/dL vs 2.62 ± 1.19 g/dL; P = .003), higher blood loss (293 vs 203 mL; P = .002) and increased need for a transfusion (21% vs 2.6%; P = .038) compared to the controls. No outcome measure was found to be significantly different for primary and revision knee surgery. CONCLUSIONS: The results of this study suggest that patients with VWD undergoing primary or revision total hip and knee arthroplasty have higher levels of blood loss than the control cohort. Perioperative protective measures including meticulous surgical techniques should be considered.

PARP1 inhibition radiosensitizes HNSCC cells deficient in homologous recombination by disabling the DNA replication fork elongation response.

There is a need to develop new, more efficient therapies for head and neck cancer (HNSCC) patients. It is currently unclear whether defects in DNA repair genes play a role in HNSCCs' resistance to therapy. PARP1 inhibitors (PARPi) were found to be "synthetic lethal" in cancers deficient in BRCA1/2 with impaired homologous recombination. Since tumors rarely have these particular mutations, there is considerable interest in finding alternative determinants of PARPi sensitivity. Effectiveness of combined irradiation and PARPi olaparib was evaluated in ten HNSCC cell lines, subdivided into HR-proficient and HR-deficient cell lines using a GFP-based reporter assay. Both groups were equally sensitive to PARPi alone. Combined treatment revealed stronger synergistic interactions in the HR-deficient group. Because HR is mainly active in S-Phase, replication processes were analyzed. A stronger impact of treatment on replication processes (p = 0.04) and an increased number of radial chromosomes (p = 0.003) were observed in the HR-deficient group. We could show that radiosensitization by inhibition of PARP1 strongly correlates with HR competence in a replication-dependent manner. Our observations indicate that PARP1 inhibitors are promising candidates for enhancing the therapeutic ratio achieved by radiotherapy via disabling DNA replication processes in HR-deficient HNSCCs.