Isometry of anteromedial reconstructions mimicking the deep medial collateral ligament depends on the femoral insertion.

PURPOSE: This study aimed to investigate the length change patterns of the native deep medial collateral ligament (dMCL) and potential anteromedial reconstructions (AMs) that might be added to a reconstruction of the superficial MCL (sMCL) to better understand the control of anteromedial rotatory instability (AMRI). METHODS: Insertion points of the dMCL and potential AM reconstructions were marked with pins (tibial) and eyelets (femoral) in 11 cadaveric knee specimens. Length changes between the pins and eyelets were then tested using threads in a validated kinematics rig with muscle loading of the quadriceps and iliotibial tract. Between 0° and 100° knee flexion, length change pattern of the anterior, middle and posterior part of the dMCL and simulated AM reconstructions were analysed using a rotary encoder. Isometry was tested using the total strain range (TSR). RESULTS: The tibiofemoral distance of the anterior dMCL part lengthened with flexion (+12.7% at 100°), whereas the posterior part slackened with flexion (-12.9% at 100°). The middle part behaved almost isometrically (maximum length: +2.8% at 100°). Depending on the femoral position within the sMCL footprint, AM reconstructions resulted in an increase in length as the knee flexed when a more centred position was used, irrespective of the tibial attachment position. Femoral positioning in the posterior aspect of the sMCL footprint exhibited <4% length change and was slightly less tight in flexion (min TSR = 3.6 ± 1.5%), irrespective of the tibial attachment position. CONCLUSION: The length change behaviour of potential AM reconstructions in a functionally intact knee is mainly influenced by the position of the femoral attachment, with different tibial attachments having a minimal effect on length change. Surgeons performing AM reconstructions to control AMRI would be advised to choose a femoral graft position in the posterior part of the native sMCL attachment to optimise graft length change behaviour. Given the high frequency of MCL injuries, sufficient restoration of AMRI is essential in isolated and combined ligamentous knee injuries. LEVEL OF EVIDENCE: There is no level of evidence as this study was an experimental laboratory study.

Hygienestandards im OP ­ führen sie nachhaltig zur Verbesserung der Qualität?

BACKGROUND: In Germany, nosocomial infections and postoperative wound infections are a significant burden for the healthcare system and the patients affected. A postoperative wound infection is often accompanied by a massive deterioration in the quality of the treatment success of surgical measures in terms of patient stress, the functional results and the cost-effectiveness of a treatment for the service provider. The aim of this article is to present the current hygiene requirements for the perioperative setting in a comprehensible manner and to explain them to everyone involved in the surgical procedure. METHOD: First of all, the importance of hygienic measures is explained, as well as a brief overview of the development up to modern hygiene concepts of today. Then the current recommendations of the KRINKO (Commission for Hospital Hygiene and Infection Prevention at the Robert Koch Institute): "Prevention of postoperative wound infections, recommendation of the Commission for Hospital Hygiene and Infection Prevention (KRINKO) at the Robert Koch Institute" are presented. CONCLUSION: Hygienic work is a basic prerequisite for work in the surgical area, because convincing treatment results with good functional results cannot be achieved in many areas (e.g. modern endoprosthetics) without sufficient hygiene. The modern requirements for hygienic work are complex and affect all areas of the hospital. The best possible degree of process quality can only be guaranteed if all pillars of modern hygiene concepts are observed.