Fredericson Michael, Jennings Fabio, Beaulieu Christopher, Matheson Gordon O
Division of Sports Medicine, Department of Orthopaedic Surgery, Stanford University School of Medicine, Stanford, CA 94305-5336, USA.
Top Magn Reson Imaging. 2006 Oct;17(5):309-25. doi: 10.1097/RMR.0b013e3180421c8c.
A stress fracture is a partial or complete bone fracture that results from repeated application of stress lower than the stress required to fracture the bone in a single loading. Otherwise healthy athletes, especially runners, sustain stress injuries or fractures. Prevention or early intervention is the preferable treatment. However, it is difficult to predict injury because runners vary with regard to biomechanical predisposition, training methods, and other factors such as diet, muscle strength, and flexibility. Stress fractures account for 0.7% to 20% of all sports medicine clinic injuries. Track-and-field athletes have the highest incidence of stress fractures compared with other athletes. Stress fractures of the tibia, metatarsals, and fibula are the most frequently reported sites. The sites of stress fractures vary from sport to sport (eg, among track athletes, stress fractures of the navicular, tibia, and metatarsal are common; in distance runners, it is the tibia and fibula; in dancers, the metatarsals). In the military, the calcaneus and metatarsals were the most commonly cited injuries, especially in new recruits, owing to the sudden increase in running and marching without adequate preparation. However, newer studies from the military show the incidence and distribution of stress fractures to be similar to those found in sports clinics. Fractures of the upper extremities are relatively rare, although most studies have focused only on lower-extremity injuries. The ulna is the upper-extremity bone injured most frequently. Imaging plays a key role in the diagnosis and management of stress injuries. Plain radiography is useful when positive, but generally has low sensitivity. Radionuclide bone scanning is highly sensitive, but lacks specificity and the ability to directly visualize fracture lines. In this article, we focus on magnetic resonance imaging, which provides highly sensitive and specific evaluation for bone marrow edema, periosteal reaction as well as detection of subtle fracture lines.
应力性骨折是一种部分或完全性骨折，它是由反复施加低于单次负荷使骨骼骨折所需应力的应力所导致的。原本健康的运动员，尤其是跑步者，容易遭受应力性损伤或骨折。预防或早期干预是较为理想的治疗方法。然而，由于跑步者在生物力学易感性、训练方法以及其他因素（如饮食、肌肉力量和柔韧性）方面存在差异，所以很难预测损伤情况。应力性骨折占所有运动医学门诊损伤的0.7%至20%。与其他运动员相比，田径运动员应力性骨折的发生率最高。胫骨、跖骨和腓骨的应力性骨折是报告最多的部位。应力性骨折的部位因运动项目而异（例如，在田径运动员中，舟骨、胫骨和跖骨的应力性骨折很常见；在长跑运动员中，是胫骨和腓骨；在舞者中，是跖骨）。在军队中，跟骨和跖骨是最常被提及的损伤部位，尤其是新兵，这是由于在没有充分准备的情况下突然增加跑步和行军所致。然而，军队的最新研究表明，应力性骨折的发生率和分布与运动医学门诊中的情况相似。上肢骨折相对少见，尽管大多数研究仅关注下肢损伤。尺骨是上肢最常受伤的骨骼。影像学在应力性损伤的诊断和管理中起着关键作用。平片检查呈阳性时有用，但一般敏感性较低。放射性核素骨扫描高度敏感，但缺乏特异性且无法直接显示骨折线。在本文中，我们重点关注磁共振成像，它能对骨髓水肿、骨膜反应以及细微骨折线的检测提供高度敏感和特异的评估。
