Tibial shaft fractures

INTRODUCTION

Closed tibial fractures are common long-bone fractures. Greater than 70,000 hospitalizations, 800,000 office visits and 500,000 hospital days, have been attributed to tibial shaft fractures. The presence of significant osteoporosis increases the risk for compound or more complex fractures with higher morbidity [1].

This topic will review issues related to tibial shaft fractures. A general overview of tibial fractures is presented separately. (See "Overview of tibial fractures".)

PERTINENT ANATOMY

The tibia is the major weight-bearing bone of the lower leg (figure 1 and figure 2). The proximal portion of the bone, the tibial plateau, forms the lower surface of the knee joint. The tibial shaft bridges the distance to the distal tibia which contributes the superior articular surface of the ankle joint at the tibiotalar articulation as well as the medial malleolus. Another key bony landmark is the tibial tuberosity which sits several centimeters below the joint line and the inferior patellar pole and serves as the attachment site for the patellar tendon [2].

A strong fibrous structure, the interosseous membrane connects the tibia and fibula along the length of the two bones. Proximally, this structure, reinforced by strong anterior and posterior ligaments, forms a synovial joint, the proximal tibiofibular articulation. Distally the interosseous membrane and three ligaments, the anterior, posterior and transverse tibiofibular ligaments stabilize the superior ankle joint. Another fibrous structure the crural fascia surrounds the bones and muscles of the lower leg. Fascial extensions and the interosseous membrane separate the muscles, nerves and vessels of the lower leg into four distinct compartments (picture 1). Three of these, the anterior, posterior and deep posterior compartments all border the tibia and can be compromised by tibial injury.

Nerves and vessels lie within the anterior and the deep posterior compartments and trauma that causes significant swelling in these compartments can result in neurovascular compromise. The key blood supply of the tibia arises from periosteal vessels and the nutrient artery. The nutrient artery originates from the posterior tibial artery and enters the posterolateral cortex at the middle third of the tibial shaft near the origin of the soleus muscle. Fractures in this region potentially compromise this blood supply. The periosteal vessels provide a less vulnerable circulation as they derive an abundant blood supply from the anterior tibial artery which travels down along the interosseous membrane. Vascular compromise can arise more proximally from marked effusion of the knee joint or trauma that affects the popliteal artery before it branches into the anterior and posterior tibial arteries or at the level of the anterior tibial artery as it branches off the popliteal artery and passes through a gap in the interosseous membrane [2].