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The market for orthopedic implants is growing rapidly with the increasing prevalence of orthopedic diseases in an aging society. Different designs and materials have been developed over the years and have, in general, shown excellent results in pre-clinical testing. However, there have been incidences of serious complications when novel implants or materials are put into clinical use, with some well-known cases being metallosis in patients implanted with metal-on-metal hip replacements and osteolysis from polyethylene wear debris generated in hip and knee joint replacements. Unforeseen factors related to new designs, materials and surgical techniques can lead to different outcomes for pre-clinical testing and clinical use. While often an excellent indicator of a device's performance in clinical settings, pre-clinical testing does sometime fail to predict critical flaws in implant development. This article aims to explore the gaps in the current approach to testing. The ISO international standard of pre-clinical testing should be modified to more adequately capture actual clinical use of the implant and simulate daily activities. This article will also introduce modern methods for implant development, such as FEM, 3D printing and computer-aided orthopedic surgery, which can be widely applied to improve pre-clinical testing procedures and reduce the incidence of surgical malalignment by analyzing biomechanical performance, planning surgical procedure and providing surgical guide.

To validate the previous anatomic study result about angle nerve of facial nerve through 3-dimensional (3-D) visualization technique, so as to provide theory basis for clinic treatment of nerve loss.The full-thickness soft tissue at internal side of inner canthus was harvested from adult cadaveric head. The skin was 3 cm in length and 1 cm in width, with 2 parallel cut lines as location markers. The specimen was sliced continuously into 120 slices, with 10 microm in thickness for every slice, 0.25 mm apart. The slices underwent HE staining and 2-D digital image was gained by high resolution scanner. Then 3-D reconstruction was performed.(1) It showed the 3-D structures and routes of angle nerve, as well as the relationship between angle nerve and angle arteriovenous. All the reconstructed structures can be displayed together or separately, also from any angles. (2) It confirmed the accuracy of microscopic anatomy study about angle nerve. (3) The 3-D reconstruction of angle nerve, as well as the surrounding structure could be very useful for clinical application.Based on the histologic study and computer technology, the 3-D reconstruction of angle nerve could provide accurate basis for the feasibility of clinic treatment of angle nerve loss.

To discuss the midface aging mechanism through anatomic study of malar fat pad.10 fresh adult cadaveric heads (20 sides) fixed by vascular perfusion of formalin were used for anatomic study with microsurgery technique under microscope. The midfacial ligament and connective tissue between skin and subcutaneous fat were observed carefully in different parts of midface. The location, shape and extent of malar fat pad was also recorded and photographed.The malar fat pad has a triangle shape. The bottom is a curve along the orbicularis retaining ligament at the lower eyelid. The fat pad is extended internally to the nasolabial fold and labiomandibular fold, externally from the major zygomatic muscle end point at the malar surface to the angulus oris and submandibular edge. (2) The malar fat pad is composed of meshed fibrous tissue, with big fat particles in it. It becomes tight when being stretched in horizontal direction along nasolabial fold and loosen when being stretched in vertical direction. (3) There is tight connection between skin and fat pad, which is divided into four areas as I, II, III, IV. The areas I, II, III are strip-shaped parelled to the nasolabial fold. The area IV is a irregular quadrilateral. (4) There are six fixation ligaments between malar fat pad and deep tissue: orbicularis retaining ligament upper layer of lower eyelid, orbicularis retaining ligament substratum of lower eyelid, zygomaticus ligament, zygomatic cutaneous ligament, zygomatic cutaneous ligament substratum, platysma There are four closely connected areas cutaneous forward ligament, cheek maxilla ligament.between the facial skin and malar fat pad which makes malar fat pad and skin keep relatively consistent. The malar fat pad moving down mainly resulted from slack of ligaments support which is one of the reasons for aging face.

To study the anatomy of angular nerve (AN), so as to provide safe approach for the denervation surgery of corrugator supercilii, depressor supercilii and procerus.10 fresh cadaver (20 sides)were perfused and fixed with formalin. Dissection was performed in the 10 x operating microscope. The plexus of the zygomatic branch and the buccal branch were detected to confirm the AN. The relationship of AN with the surrounding blood vessels was observed. We tracked AN until it entered corrugator supercilii, depressor supercilii and procerus.(1) AN was classified into I, II, III type according to its formation pattern. Type I (20%, 4/20 sides) AN is single, which is mainly from the plexus of buccal branch plus the zygomatic branch from the orbicularis oculi muscle. In type II (20%, 4/20 sides), the single AN was formed by buccal branch plexus and zygomatic branch plexus in the "Four Muscle Gap". In type III (60%, 12/20 sides), the AN had two branches in the "Four Muscle Gap". (2) The three types AN passed inferior to the support ligament at the suborbital part, and then transversed medial to the support ligament at the medial canthus, along the vessels of medial canthus. (3) The branch of AN enters the depressor supercilii or procerus 2.19 to 4.28 mm above the medial canthus ligament. The backward branch enters the levator labii superioris alaeque nasi 6.89 to 9.38 mm below the medial canthus ligament.The approach of denervation surgery for AN should be performed medial to the support ligation, between 2.19 mm above the medial canthus and 6.89 mm below the medial canthus.