The radiographic relationship between the cortical overlap view (COV) and the tip of the greater trochanter.

For proximal femoral nailing, choosing the proper entry point with the aid of C-arm imaging is crucial. Therefore, obtaining accurate radiological views that facilitate sound identification of the tip of the greater trochanter (GT) is of utmost importance. The aim of this study was to define a radiological view characterised by reproducible radiographic landmarks which will allow the reliable identification of the tip of the GT in the anteroposterior view. Anatomical and radiographic features of 16 cadaveric femurs were analysed. The cortical overlap view (COV), characterised by the radiological overlap of the density line of the piriform fossa and the intertrochanteric crest, was identified. It marks the rotation of the proximal femur at which the GT can be accurately identified and used to determine the desired entry point for a proximal femoral nail. Trainees and fully qualified orthopedic trauma surgeons were asked to identify the correct COV in radiological imaging series. Mean internal rotation of the femur to achieve a COV was 17.5° (range 12.8°-21.8°). In the COV the tip of the GT is the highest visible point and the mean distance from the cortical overlap line to the tip of the GT is 4.45 mm. Intra- and inter-rater reliability was high with ICC(2,k) = 0.932 and ICC(2,k) = 0.987 respectively. Trainees achieved higher rates of correct COV identification than specialists. There was no significant correlation between the internal rotation of the femur to achieve the COV and femoral antetorsion. In conclusion, the COV is a highly reproducible radiological view that is characterised by radiographic landmarks easy to recognise. It allows for accurate identification of the tip of the GT, which can be used by the surgeon as a reference to determine the desired entry point for an intramedullary nail.

Preserving the lower extremity after severe devolving injuries to meet the patient's demand in two cases: (Limb salvage after degloving injury).

BACKGROUND: Severe injuries of the foot are a life-changing event. They often lead to some form of disability, and are therefore very challenging to manage. Injuries of the extremity, especially the foot and ankle, are distinct predictors of poor outcome in polytrauma patients.Degloving injuries of the lower extremity involving the heel and foot are a rare and unique subgroup of severe foot injuries.Treating degloving injuries is challenging. The surgical approach has to take into consideration both osseous and massive soft tissue injuries aiming to preserve the unique architecture of the lower limb and reconstruct the soft tissue.There are several surgical approaches for treating degloving injuries of the lower limb. CASE PRESENTATION: We would like to share our experience with two cases of young very active patients who suffered from a complex injury of the lower limb that included a massive degloving injury. It was of paramount importance to salvage the lower limb and keep it functional.Both patients were treated while using the degloved skin as a defatted full thickness skin flap that was replanted on the injured limb followed by application of VAC-therapy. CONCLUSION: We treated two patients suffering a severe degloving injury of the lower extremity with degloved skin as a full thickness flap in order to preserve both the extremity itself as well as the function of the lower limb according to the individual requirements of the patients. Consequently, we could enable the patient to pursue their professional musical training requiring subtle use of the lower extremity as well as ensuring sufficient function of the lower extremity in everyday use.

The nail-shaft-axis of the of proximal femoral nail antirotation (PFNA) is an important prognostic factor in the operative treatment of intertrochanteric fractures.

INTRODUCTION: Due to the world's aging population, intertrochanteric fractures are frequent. Considering age and comorbidities of most of these patients, it is indispensable to enable early postoperative mobilization of these patients. Intramedullary osteosynthesis with PFN-A is widely used and, in general, considered safe and reliable for the operative treatment of intertrochanteric fractures. However, implant -related complications are reported in 6-21% of all cases. In this study, we are analyzing complication rates and risk factors for implant-related complications. MATERIALS AND METHODS: All intertrochanteric fractures admitted to our hospital and treated with PFN-A between January 2012 and January 2016 were analysed retrospectively. Radiological analyses of the CCD and the lateral offset on the uninjured side was compared to the CCD initially postoperatively and during follow-up on the operated side. Furthermore, we analysed the tip-apex distance (TAD), blade position in the femoral head and introduced the nail-shaft axis as a new parameter. RESULTS: Within 101 intertrochanteric fractures included, 16 implant-related complications were encountered (15.84%). Analyses of risk factors for secondary varus displacement of greater than 10° within the follow-up and thus risk for cut-out in the osteosynthesis revealed that etasblished risk factors such as a TAD > 25 mm, reduction in varus and an improper position of the blade were also significant risk factors in our cohort for failure of the osteosynthesis. Moreover, we introduced the nail-shaft axis a new potential risk factor and could show that a too medial or too lateral nail-shaft axis is also significantly associated with secondary varus displacement. CONCLUSION: When treating introchanteric fractures with PFNA reduction in neutral or even slight valgus, aiming for a TAD < 25 mm and a correct position of the blade within the femoral head reduced the risk for secondary varus displacement significantly. Furthermore, we suggest to aim for a central nail-shaft axis.

Direct crosstalk between cancer and osteoblast lineage cells fuels metastatic growth in bone via auto-amplification of IL-6 and RANKL signaling pathways.

The bone microenvironment and its modification by cancer and host cell interactions is a key driver of skeletal metastatic growth. Interleukin-6 (IL-6) stimulates receptor activator of NF-κB ligand (RANKL) expression in bone cells, and serum IL-6 levels are associated with poor clinical outcomes in cancer patients. We investigated the effects of RANKL on cancer cells and the role of tumor-derived IL-6 within the bone microenvironment. Using human breast cancer cell lines to induce tumors in the bone of immune-deficient mice, we first determined whether RANKL released by cells of the osteoblast lineage directly promotes IL-6 expression by cancer cells in vitro and in vivo. We then disrupted of IL-6 signaling in vivo either via knockdown of IL-6 in tumor cells or through treatment with specific anti-human or anti-mouse IL-6 receptor antibodies to investigate the tumor effect. Finally, we tested the effect of RANK knockdown in cancer cells on cancer growth. We demonstrate that osteoblast lineage-derived RANKL upregulates secretion of IL-6 by breast cancers in vivo and in vitro. IL-6, in turn, induces expression of RANK by cancer cells, which sensitizes the tumor to RANKL and significantly enhances cancer IL-6 release. Disruption in vivo of this auto-amplifying crosstalk by knockdown of IL-6 or RANK in cancer cells, or via treatment with anti-IL-6 receptor antibodies, significantly reduces tumor growth in bone but not in soft tissues. RANKL and IL-6 mediate direct paracrine-autocrine signaling between cells of the osteoblast lineage and cancer cells, significantly enhancing the growth of metastatic breast cancers within bone.