الفهرس 
ANATOMY AND BIOMECHANICSOnly 14 pages are availabe for public view
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Abstract
The talus has a unique anatomic shape and function that predisposes it to uncommon but often serious injuries, It has seven articular surfaces. The calcaneal articular facets form the subtalar joint, the anteromedial trochlear surface, central trochlear surface, and lateral process form the talar portion of the ankle joint. The talus is held in the ankle by bony constraints, the medial and lateral malleolus, and constraining ligaments. Talar fractures are uncommon, constituting less than 1% of all reported fractures, and only 3% to 6% of all foot fractures.
Most talar fractures result from high-energy trauma and have a high rate of associated injuries. Approximately 50% of all talar fractures occur through the talar neck, which is the portion of the talus that has the smallest cross-sectional area and is covered with a relatively weak cortex. High-energy trauma that produces displaced talar neck fractures interrupts the blood supply of the talus and often causes varying degrees of articular cartilage damage. Obtaining satisfactory clinical results while avoiding complications presents a unique challenge in the treatment of talar neck fractures.
Talus fractures have confounded physicians for centuries. Reports as early as 1820 have demonstrated poor outcomes and a high mortality rate after this injury and its subsequent management, leading some early surgeons to recommend amputation as the primary treatment
As anesthesia has evolved as a distinct specialty and modern orthopedic techniques have been developed, numerous case series and reports of talus fractures have been published, with wide variations in treatment strategies and patient outcomes. Despite modern advances, talar neck fractures continue to represent problematic injuries that are associated with numerous complications and less than satisfactory results after treatment. The current published studies impart valuable information but lack the meta-analyses and systematic reviews necessary to guide clinical practice. Thus, the treatment of talar neck fractures has relied on longstanding paradigms and traditions. The present systematic review was undertaken in an attempt to further define the complication rates, prognoses as they relate to injury severity, effects of surgical delay, functional outcomes after treatment, and incidence of secondary operative procedures.
Talar neck fractures have been associated with a high incidence of complications, including osteonecrosis, infection, skin necrosis, malunion, non-union, and posttraumatic arthritis. The high-energy nature of the injury required to produce a displaced talar neck fracture also causes severe associated soft tissue damage, including damage to the precarious blood supply. Anatomic reduction and internal fixation of displaced neck fractures to restore and to maintain alignment has a key role in minimizing the complications rate. However, the sequelae of posttraumatic complications may be inevitable. Even in the absence of steonecrosis following anatomic fracture reduction and fixation, patients frequently experience chronic pain and stiffness due to post-traumatic arthritis.
Likewise , osteonecrosis of the talus is a significant complication. In many cases, however, the radiographic appearance of osteonecrosis may not correlate with permanent disability.