Bone is formed through the processes of endochondral and intramembranous ossification. In endochondral ossification primary mesenchymal cells differentiate to chondrocytes and then are progressively substituted by bone, while in intramembranous ossification mesenchymal stem cells (MSCs) differentiate directly into osteoblasts to form bone. The steps of osteogenic proliferation, differentiation,...

A century ago, in 1909, Martin Kirschner (1879-1942) introduced a smooth pin, presently known as the Kirschner wire (K-wire). The K-wire was initially used for skeletal traction and is now currently used for many different goals. The development of the K-wire and its insertion devices were mainly influenced by the change in operative goals and by the introduction of antibiotics. The first versi...

Osteochondritis dissecans is a condition primarily found in the knee, elbow, and ankle, which affects subchondral bone and potentially the overlying articular cartilage. Although the etiology is not certain, possible causative factors include repetitive microtrauma, ischemia, genetic and endocrine factors, and anomalies of ossification. The etiology, presentation, and management is age-dependen...

background. improving the implantation conditions in order to reduce the failure is always desirable for researchers. the aim of this study was to compare two different types of dental implant materials from biomechnical viewpoint in order to introduce a novel simulation method to select suitable materials for dental implants. methods. in this research, drilling process was performed in the cor...

A new arthroscopic approach for traumatic instability has been developed with which avulsed capsulolabral tissue can be effectively attached to the glenoid articular rim with sutures, providing anatomic reattachment and effective deepening of the glenoid concavity similar to that achieved by open repair. This technique does not depend on fixation devices, trans-scapular drilling, or implantatio...

Good flow and pressure control is essential for successful Underbalanced Drilling (UBD) operations. This work evaluates the use of Model Predictive Control (MPC) for integrated control of well conditions and the topside separation system during UBD. The downhole well pressure, separator liquid levels, and the separator pressure are controlled by manipulation of the rig pump, the choke, and the ...

Nowadays, underground structures play vital role in developing different countries. Such structures are constructed in many civil activities such as development of road and railways, subways, water, gas and sewage lines, underground subways, nuclear wastes land filling, fuel storage and military installations. With an appropriate drilling method being selected, instabilities created in tunnels ...

Intramedullary nailing is a technically demanding procedure which involves an excessive amount of x-ray acquisitions; one study lists as many as 48 to successfully complete the procedure. In this work, a novel low cost radiation-free drilling guide is designed to assist surgeons in completing the distal locking procedure without any x-ray acquisitions. Using an augmented reality fluoroscope tha...

BACKGROUND Osteochondrosis dissecans is a disorder of the subchondral bone potentially affecting the adjacent articular cartilage. There remains disunity with regard to treatment methods. CASE PRESENTATION We present the case of a 21-year-old Swiss woman who presented with clinically symptomatic bilateral osteochondrosis dissecans lesions at both medial femoral condyles. She underwent sequent...