Complex multifault rupture during the 2016 Mw 7.8 Kaikoura earthquake, New Zealand.

On 14 November 2016, northeastern South Island of New Zealand was struck by a major moment magnitude (Mw) 7.8 earthquake. Field observations, in conjunction with interferometric synthetic aperture radar, Global Positioning System, and seismology data, reveal this to be one of the most complex earthquakes ever recorded. The rupture propagated northward for more than 170 kilometers along both mapped and unmapped faults before continuing offshore at the island's northeastern extent. Geodetic and field observations reveal surface ruptures along at least 12 major faults, including possible slip along the southern Hikurangi subduction interface; extensive uplift along much of the coastline; and widespread anelastic deformation, including the ~8-meter uplift of a fault-bounded block. This complex earthquake defies many conventional assumptions about the degree to which earthquake ruptures are controlled by fault segmentation and should motivate reevaluation of these issues in seismic hazard models.

Problems of bridging plate fixation for the treatment of forearm shaft fractures with the locking compression plate.

INTRODUCTION: Treatment of diaphyseal forearm fractures by open reduction and internal plate fixation is a well-accepted strategy. In a variety of fracture localizations, the use of bridging plate fixation with locking compression plates (LCP) has been shown to improve biomechanical and biological characteristics. Only very limited clinical data are available on bridging plate fixation using LCPs for the treatment of diaphyseal forearm fractures. The aims of this study were to assess both clinical outcomes of LCP fracture treatments, and the implant-specific advantages and disadvantages. METHOD: The study consisted of 53 patients. All relevant data were extracted from the medical reports and radiographs. Of the 53 patients, 39 completed the disabilities of the arm, shoulder and hand (DASH) questionnaire and 35 patients were available for clinical examination. The mean time of follow-up was 23.3 months. RESULTS: Thirty-nine fractures of the radius and 45 fractures of the ulna were treated with 3.5 mm LCPs. Due to a fracture non-union, four patients underwent a second operation. In 13 patients, hardware had already been removed at the time of follow-up. Complete documentation of the removal operation was available for ten patients; in seven of these, procedures difficulties occurred. Mean ranges of motion were 138°, 141° and 162° for elbow flexion-extension, wrist flexion-extension and pronation-supination, respectively. The mean DASH score was calculated at 14.9. CONCLUSION: In conclusion, our data show that clinical and functional outcomes of LCP plating of diaphyseal forearm fractures are comparable to the use of conventional implants. However, implant-specific problems during hardware removal must be considered.

Bone debris: dead matter or vital osteoblasts.

BACKGROUND: Mechanical manipulation, pressure, and temperature increase can induce bone necrosis during intramedullary reaming. METHODS: In this study, the bone debris obtained after reaming 18 sheep tibiae was analyzed to investigate its vitality by measuring alkaline phosphatase activity. Two different reamer designs were used for the project. Bone cells were first cultivated in a specific growth medium, counted 3 weeks after the reaming procedure, and then cultivated for another 5 weeks. RESULTS: At the end of the project, qualitative evaluation showed positive alkaline phosphatase activity in most of the cases, and quantitative evaluation also showed enzyme activity. The positive alkaline phosphatase results were independent of the reamer sizes and reamer design. No significant results were obtained from a comparison of different reamer sizes and designs. This indicates that osteoblasts survive after correctly performed reaming. CONCLUSION: The results prove the vitality of the bone debris and confirm clinical observations.