Arthroscopic and open reconstruction of the posterolateral corner of the knee have equally good clinical results: first results of a prospective 12-month follow-up study.

PURPOSE: Arthroscopic reconstruction techniques for higher-grade posterolateral corner (PLC) injuries (Fanelli Type B, PoLIS LI-B) have not yet been validated in clinical studies. The open reconstruction technique described by Arciero is well-established and showed good restoration of joint stability in previous studies. This study aimed to compare clinical outcomes of this established open surgery technique to a newly developed arthroscopic technique in a prospective randomized clinical trial. METHODS: Between 2019 and 2021, this study focused on chronic high-grade PLC injuries (Fanelli Type B, PoLIS LI-B). Group A consisted of patients treated with conventional open surgery following Arciero's technique, while Group B included patients treated with Arciero's arthroscopic technique. All cases underwent additional PCL reconstruction. After a minimum 12-month follow-up, clinical scores and objective stability assessments were compared between the groups. RESULTS: In total, 26 (group A 12, group B 14) eligible patients with a mean follow-up of 14.9 ± 7.2 months were evaluated in the present study. Knee stability and patient-reported outcome scores (PROMS) were significantly improved when comparing pre- and post-operative values (p < 0.0001). No clinically relevant differences in PROMS (Lysholm: A 83.9 ± 11.4 vs. B 85.3 ± 13.8; IKDC: A 76.91 ± 12.6 vs. B 76.8 ± 15.7) were shown in both groups. Additionally, no statistically significant differences were detected between groups with respect to external rotation, range of motion and instrumental stability testing. Arthroscopic reconstruction showed significantly shorter operation time (p = 0.0109). There were no clinical failures or neurovascular complications of the surgical procedures. CONCLUSION: Both surgical techniques for isolated chronic PLC Fanelli Type B injuries significantly improved the knee stability, were equivalent with respect to PROMs and led to good clinical results. However, arthroscopic PLC reconstruction was associated with a shorter surgery time compared to open PLC reconstruction. Therefore, arthroscopic PLC reconstruction may be a viable option in the hands of an experienced surgeon. LEVEL OF EVIDENCE: Prospective cohort study, II.

Hoffa fractures are associated with concomitant soft tissue injures and a high postoperative complication rate.

INTRODUCTION: Hoffa fractures are a rare and often overlooked entity. The main goal of surgical treatment is to restore the articular surface and maintain knee function. However, current clinical data indicate heterogeneous outcomes. The aim of this multicenter study was to obtain a representative data set of patients with isolated Hoffa fractures with special emphasis on concomitant soft tissue injuries, diagnostic algorithms, treatment strategies and functional outcomes. MATERIALS AND METHODS: Participating Level I trauma centres were asked to review their internal database for isolated Hoffa fractures treated surgically between 2010 and 2020. Demographics, mechanism of injury, diagnostic and therapeutic algorithm, Letenneur classification, concomitant soft tissue injuries, and postoperative knee function and complications were analysed. RESULTS: A total of 56 patients from six participating trauma centres were included. The median age at injury was 45 years (15-94) with a median follow-up of 19 months (2-108). The most common mechanism of injury was high-energy trauma, with unicondylar lateral Letenneur type I and II fractures being the most common. Surgical treatment was independent of the type of fracture and included isolated screw fixation, combined plate and screw fixation and isolated plate osteosynthesis. Isolated screw fixation resulted in significantly better range of motion (ROM) values (p = 0.032), but the highest number of postoperative complications (n = 14/20, n.s.) compared to the other fixation techniques. The highest number of fixation failures requiring revision was observed in the plate and screw fixation group (n = 3/8, p = 0.008). Osteochondral flake fractures (n = 12/43, 27%) and lateral meniscus injuries (n = 5/49, 10%) were commonly seen in Hoffa fractures. CONCLUSIONS: Treatment of Hoffa fractures with screw fixation resulted in significantly better functional outcomes, probably due to less comminuted fractures. Concomitant cartilage, meniscal and ligamentous injuries are common and warrant preoperative recognition and management.

Current standard of care for distal femur fractures in Germany and Switzerland.

BACKGROUND: Distal femur fractures occur with an incidence of 4.5/100,000 and show a prevalence of 0.4%. Causes include low-impact trauma in older patients and high-impact trauma in younger patients without pre-existing medical conditions. The aim of this study was to perform a comprehensive evaluation of trauma mechanisms, trauma-promoting factors, comorbidities, medication history and type of surgical care to provide an overview of the causes of injury and the most appropriate therapeutic approach. METHODS: In this multicenter cohort study a retrospective analysis of 229 patients who sustained a distal femur fracture between January 2011 and December 2020 was performed. Individual fracture patterns, fracture predisposing factors, concomitant disease profiles, medication history, treatment strategy and associated complications were analyzed. RESULTS: 229 patients were included in the retrospective analysis. A total of 113-type 33 A, 50-type 33 B and 66-type 33 C fractures were diagnosed, of whom 92% received a lateral locking plate osteosynthesis. There was a complication in 14.4% of all cases, of which 6.1% were attributable to infection. Significant risk factors for developing a complication were an increased BMI (29.9 ± 8.5 kg/m2; p = 0.04), fracture displacement of over half a shaft width (p < 0.001) and AOC fractures (p < 0,016), specifically C2 fractures (p < 0,008). CONCLUSION: In this multicenter retrospective cohort study, lateral locking plate osteosynthesis was the method of choice and was selected in over 90% of cases, regardless of the fracture classification and risk factors. A complication rate of 14.4% emphasizes the necessary analysis of patient- and care-specific risk factors and a resulting adjustment of the therapy strategy. An increased BMI (29.9 ± 8.5 kg/m2; p = 0.04), fracture displacement of over half a shaft width (p < 0.001) and AOC fractures (p < 0,016), specifically C2 fractures (p < 0,008) increase the risk of developing a complication and should prompt an early switch to a treatment strategy that provides more stability.

Sendai virus infection induces apoptosis through activation of caspase-8 (FLICE) and caspase-3 (CPP32).

Sendai virus (SV) infection and replication lead to a strong cytopathic effect with subsequent death of host cells. We now show that SV infection triggers an apoptotic program in target cells. Incubation of infected cells with the peptide inhibitor z-VAD-fmk abrogated SV-induced apoptosis, indicating that proteases of the caspase family were involved. Moreover, proteolytic activation of two distinct caspases, CPP32/caspase-3 and, as shown for the first time in virus-infected cells, FLICE/caspase-8, could be detected. So far, activation of FLICE/caspase-8 has been described in apoptosis triggered by death receptors, including CD95 and tumor necrosis factor (TNF)-R1. In contrast, we could show that SV-induced apoptosis did not require TNF or CD95 ligand. We further found that apoptosis of infected cells did not influence the maturation and budding of SV progeny. In conclusion, SV-induced cell injury is mediated by CD95- and TNF-R1-independent activation of caspases, leading to the death of host cells without impairment of the viral life cycle.

Quantification of VP22-GFP spread by direct fluorescence in 15 commonly used cell lines.

BACKGROUND: The intercellular transport property of VP22 chimeric proteins offers the opportunity for the improvement of gene therapy delivery systems. Since enhanced therapeutic effects of transduced genes already have been exemplified for chimeric proteins VP22-p53 and VP22-tk, we were interested in examining whether spread of VP22 chimeric proteins is a general biological phenomenon not restricted to distinct tissues or species. METHODS: To study intercellular spread of VP22-GFP fusion proteins, 15 different mammalian cell lines were transfected with 200-2000 ng of VP22-GFP or GFP expression plasmids. Expression of VP22-GFP or GFP was monitored by fluorescence microscopy of live GFP fluorescence and direct FACS analysis. For selected cell lines, antibody detection of VP22-GFP spread was analysed by confocal microscopy as a control. RESULTS: Spread of VP22-GFP fusion proteins was detected in all 15 cell lines tested, and quantified by FACS analysis. Experimental conditions were found to be critical in the investigation of VP22-mediated intercellular spread. CONCLUSION: Results of our study indicate that spread of VP22 chimeric proteins is a general biological phenomenon not restricted to distinct tissues or species. Therefore, further evidence is provided that VP22-enhanced gene therapeutic effects may be obtained irrespective of the target organ/tissue to be addressed.