The number of athletes engaged in climbing sports has risen. Specific physical and psychological skills are required. The objective of this review was to determine factors for high climbing performance. We evaluated physiological, biomechanical and psychological characteristics that simplify the ascent. We also assessed training and recovery strategies. Medline (Pubmed), Cochrane Library and Google scholar up to September 2018. A low skinfold thickness, body fat and large forearm volume were anthropometric traits in successful climbers. Well-trained forearm flexors with high aerobic capacities lead to an efficient style. Hand grip strength and endurance, postural stability and optimized kinematic motions were favourable. Elite climbers had long finger and bent-arm hang times. Psychologically, an "iceberg profile" was typical. Constant training with fingerboard and dynamic eccentric-concentric training helped to push the "red-point grade". Hand, forearm strength and endurance are highly important elements in elite climbers. An efficient climbing style with perpetual focus and accuracy, high speed and low exhaustion due to adaption to repeated isometric exercise is helpful in the ascent, while low body fat and a large bone-to-tip pulp make it easier. Constant training is essential, e.g. eccentric-concentric training of finger flexors, which should be followed by active recovery.

Minimally invasive surgery has become more and more important for the treatment of traumatic spine fractures. Besides, some clinical studies, objective data regarding the possible lower damage to the surrounding tissue of the spine is still missing. Here we report a sheep model where we compared a percutaneous versus an open approach for dorsal instrumentation with pedicle screws to the spine. Twelve skeletally mature sheep underwent bilateral pedicle screw fixation at the L4–L6 level. Forty-eight pedicle screws were bilaterally inserted into the pedicles and connected with rods using either an open dorsal standard or a percutaneous approach. Operation time, blood flow, compartment pressure, radiation time, loss of blood, laboratory findings and EMG were evaluated to objectify possible advantages for the percutaneous operation technique. Loss of blood and the distribution of CK-MM as a marker for muscle damage were significantly lower in the percutaneous group. However, radiation time was significantly longer in the percutaneous group. Other parameters like compartment pressure, blood flow and also measurement of the EMG at different time points did not reveal significant differences. Based on the results we found in the present study, percutaneous screw insertion can bring moderate advantages but it should be noted that essential functional deficits to the muscle could not be detected.

The vision of gluing two bone fragments with biodegradable and biocompatible adhesives remains highly fascinating and attractive to orthopedic surgeons. Possibly shorter operation times, better stabilization, lower infection rates, and unnecessary removal make this approach very appealing. After 30 years of research in this field, the first adhesive systems are now appearing in scientific reports that may fulfill the comprehensive requirements of bioadhesives for bone. For a successful introduction into clinical application, special requirements of the musculoskeletal system, challenges in the production of a bone adhesive, as well as regulatory hurdles still need to be overcome. In this article, we will give an overview of existing synthetic polymers, biomimetic, and bio-based adhesive approaches, review the regulatory hurdles they face, and discuss perspectives of how bone adhesives could be efficiently introduced into clinical application, including legal regulations.

Osteoarthritis (OA) is a chronic disease affecting the whole joint, which still lacks a disease-modifying treatment. This suggests an incomplete understanding of underlying molecular mechanisms. The Wnt/β-catenin pathway is involved in different pathophysiological processes of OA. Interestingly, both excessive stimulation and suppression of this pathway can contribute to the pathogenesis of OA. microRNAs have been shown to regulate different cellular processes in different diseases, including the metabolic activity of chondrocytes and osteocytes. To bridge these findings, here we attempt to give a conclusive overview of microRNA regulation of the Wnt/β-catenin pathway in bone and cartilage, which may provide insights to advance the development of miRNA-based therapeutics for OA treatment.

Because of an increasing life expectancy of patients and the rising number of joint replacements, peri- and interprosthetic femoral fractures are a common occurrence in most trauma centers. This study was designed to answer two primary questions. First, whether the fracture risk increases with two intramedullary implants in one femur; and second, whether a compression plate osteosynthesis is sufficient for stabilizing an interprosthetic fracture. Twenty-four human cadaveric femurs were harvested and four groups were matched based on the basis of bone density using a peripher quantitative computer tomography (pQCT). All groups-(I) hip prosthesis with a cemented femoral stem; (II) hip prosthesis and retrograde femoral nail; (III) hip prosthesis, retrograde femoral nail, and lateral compression plate; (IV) all three implants with an additional simulated interprosthetic fracture-were biomechanically tested in a four-point bending in lateral-medial direction. The second group with two intramedullary implants exhibited 20% lower fracture strength in comparison with group 1 with proximal femoral stem only. The stabilization of an interprosthetic fracture with a lateral compression plate (group IV) resulted in a fracture strength similar to femur with prosthesis only. Two intramedullary implants reduce the fracture strength significantly. If an interprosthetic fracture occurs, sufficient stability can be achieved by a lateral compression plate. Because two intramedullary implants in the femur may decrease the fracture strength, the treatment of supracondylar femoral fractures with a retrograde nail in cases with preexisting ipsilateral hip prosthesis should be reconsidered.

MicroRNAs (miRNAs) can be transported in extracellular vesicles (EVs) and are qualified as possible messengers for cell–cell communication. In the context of osteoarthritis (OA), miR-221-3p has been shown to have a mechanosensitive and a paracrine function inside cartilage. However, the question remains if EVs with miR-221-3p can act as molecular mechanotransducers between cells of different tissues. Here, we studied the effect of EV-mediated transport in the communication between chondrocytes and osteoblasts in vitro in a rat model. In silico analysis (Targetscan, miRWalk, miRDB) revealed putative targets of miRNA-221-3p (CDKN1B/p27, TIMP-3, Tcf7l2/TCF4, ARNT). Indeed, transfection of miRNA-221-3p in chondrocytes and osteoblasts resulted in regulation of these targets. Coculture experiments of transfected chondrocytes with untransfected osteoblasts not only showed regulation of these target genes in osteoblasts but also inhibition of their bone formation capacity. Direct treatment with chondrocyte-derived EVs validated that chondrocyte-produced extracellular miR-221-3p was responsible for this effect. Altogether, our study provides a novel perspective on a possible communication pathway of a mechanically induced epigenetic signal through EVs. This may be important for processes at the interface of bone and cartilage, such as OA development, physiologic joint homeostasis, growth or fracture healing, as well as for other tissue interfaces with differing biomechanical properties.