Posterolateral Portal

The posterolateral portal is positioned similar to the anterolateral portal except at the posterior margin of the greater trochanter (see Figure 7.2). Again, it is a relatively straight shot under fluoroscopic control, but it is facilitated by direct visualization through the arthroscope from the anterolateral portal. Maintaining direct visualization is of greater importance because the posterolateral portal gets closer to major structures, specifically the sciatic nerve.

The posterolateral portal penetrates both the glu-teus medius and minimus before entering the lateral capsule at its posterior margin (Figure 7.9). Its course is superior and anterior to the piriformis tendon (Figure 7.10). It lies closest to the sciatic nerve at the level of the capsule. The distance to the lateral edge of the nerve averages 2.9 cm.

Several technical errors or alterations in technique during arthroscopy can place the sciatic nerve at greater risk. First, although hip flexion may relax the capsule, easing distraction, it may potentially draw the

FIGURE 7.6. The ascending branch of the lateral circumflex femoral artery (arrow) has an oblique course distal to the anterior portal seen here at the level of the capsule. This specimen demonstrates a terminal branch (double arrow) coursing vertically adjacent to the portal. (Reprinted with permission from Byrd et al.13)

FIGURE 7.6. The ascending branch of the lateral circumflex femoral artery (arrow) has an oblique course distal to the anterior portal seen here at the level of the capsule. This specimen demonstrates a terminal branch (double arrow) coursing vertically adjacent to the portal. (Reprinted with permission from Byrd et al.13)

Superior Gluteal N

Superior Gluteal N

Posterolateral Branch

Gluteus Médius M.

Portal

Pathway

FIGURE 7.7. Anterolateral portal pathway/relationship to superior gluteal nerve. (Courtesy of Smith & Nephew Endoscopy, Andover, MA.)

Gluteus Médius M.

Portal

Pathway

Sciatic Nerve Pathway

FIGURE 7.9. Posterolateral portal pathway/relationship to sciatic nerve and superior gluteal nerve. (Courtesy of Smith & Nephew Endoscopy, Andover, MA.)

FIGURE 7.7. Anterolateral portal pathway/relationship to superior gluteal nerve. (Courtesy of Smith & Nephew Endoscopy, Andover, MA.)

FIGURE 7.9. Posterolateral portal pathway/relationship to sciatic nerve and superior gluteal nerve. (Courtesy of Smith & Nephew Endoscopy, Andover, MA.)

sciatic nerve closer to the joint, making it more vulnerable to injury. Second, it is important to maintain neutral rotation during portal placement. If the hip is inadvertently externally rotated, this moves the greater trochanter more posterior relative to the femoral head and the hip joint (Figure 7.11). This type of starting position, again, can place the sciatic nerve more at risk for injury. Thus, although slight flexion may relax the capsule, excessive flexion should be avoided. Also, care should be taken to ensure that the hip is in neutral rotation during portal placement. Intraoperative rotation of the hip may facilitate visualiza tion of portions of the femoral head but should not be performed until after all portals have been established.

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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