Relevant Anatomy And Biomechanics

Understanding ACL anatomy is important for interpreting imaging studies and planning surgical reconstruction. The ACL is approximately 31 to 38 mm in total length and has a mid-substance cross-sectional area of 44 mm2.12,13 It courses from the

Figure 51-4 Lateral radiograph in a chronically anterior cruciate ligament-deficient patient demonstrating accentuation of the sulcus terminalis (arrow) termed the lateral notch sign.

knee revealing a classic lateral capsular avulsion (arrow), termed a Segond fracture. This patient underwent magnetic resonance imaging, which confirmed an anterior cruciate ligament tear, and underwent reconstruction.

Figure 51-4 Lateral radiograph in a chronically anterior cruciate ligament-deficient patient demonstrating accentuation of the sulcus terminalis (arrow) termed the lateral notch sign.

knee revealing a classic lateral capsular avulsion (arrow), termed a Segond fracture. This patient underwent magnetic resonance imaging, which confirmed an anterior cruciate ligament tear, and underwent reconstruction.

Figure 51-5 Sagittal magnetic resonance imaging demonstrating an intact (A) and ruptured (B) anterior cruciate ligament. Note the fiber discontinuity, hemorrhage, and sizable effusion present in the injured knee. Arrows indicated normal (A) and abnormal (B) joint capsule position.

Figure 51-6 Magnetic resonance imaging demonstrating typical bone bruise pattern encountered with acute anterior cruciate ligament injury: posterolateral tibial plateau and anterolateral femoral condyle. Arrows indicate increased signal on MRI in areas of bone bruise on femoral condyle and tibial plateau.

Figure 51-6 Magnetic resonance imaging demonstrating typical bone bruise pattern encountered with acute anterior cruciate ligament injury: posterolateral tibial plateau and anterolateral femoral condyle. Arrows indicate increased signal on MRI in areas of bone bruise on femoral condyle and tibial plateau.

posteromedial surface of the lateral femoral condyle in the intercondylar notch to its tibial attachment approximately 15 mm behind the anterior border of the tibial articular surface, just medial to the anterior horn of the lateral meniscus. At both insertion sites, the ligament attaches over a broad, flattened area that is more than three times the cross-sectional area of the mid-substance ligament.14 Additionally, the ACL has been described as being composed of two distinct anatomic and functional structures: the anteromedial and posterolateral bundles. Each bundle contributes to approximately half of the overall size of the ACL14 (Fig. 51-7).

The ligament has an ultimate tensile load of 2160 N and a stiffness of 242 N/mm and can tolerate a strain of 20% prior to failure. The forces in the intact ACL range from 100 N during passive knee extension to about 400 N with walking, and up to 1700 N with cutting and acceleration-deceleration activities.15,16 The individual bundles have been reported to have different bio-mechanical characteristics and tensioning patterns. Tension in the anteromedial bundle increases with flexion angles greater than 30 degrees, whereas the posterolateral bundle is more taut in extension.17 Additionally, the role of the posterolateral bundle in resisting coupled rotatory loads is being investigated.18

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Cure Tennis Elbow Without Surgery

Cure Tennis Elbow Without Surgery

Everything you wanted to know about. How To Cure Tennis Elbow. Are you an athlete who suffers from tennis elbow? Contrary to popular opinion, most people who suffer from tennis elbow do not even play tennis. They get this condition, which is a torn tendon in the elbow, from the strain of using the same motions with the arm, repeatedly. If you have tennis elbow, you understand how the pain can disrupt your day.

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