Port Sites

Because the hip joint is deep and surrounded by important neurovascular structures, both the skin entry point and the direction of each portal matter. A three-portal setup using an anterolateral portal, a modified mid-anterior portal, and a distal anterolateral accessory portal is common. Traditional anterior and posterolateral portals remain useful alternatives.

General principles

Before prepping, mark the anterior superior iliac spine (ASIS) and greater trochanter. A line from the ASIS toward the patella is a useful anterior safety landmark; routine portals should remain lateral to this line because the femoral neurovascular bundle lies medially.

The first portal is normally created with the hip distracted by approximately 8-10 mm. A spinal needle is used before the skin incision, followed by a guidewire and cannula. Fluoroscopy is commonly used for the first portal; subsequent portals are created under direct arthroscopic visualization. Prior to placing the first portal, air or saline can be used to distend the hip joint.

Common portals

Portal	Typical location	Role	Main structures at risk
Anterolateral portal	1-2 cm proximal and anterior to the greater trochanter	Primary viewing portal	Superior gluteal nerve if too proximal
Anterior portal	At the intersection of a horizontal line from the greater trochanter and a longitudinal line from the ASIS	Central compartment work	Lateral femoral cutaneous nerve, lateral femoral circumflex artery branches, femoral neurovascular bundle if too medial/deep
Mid-anterior portal	Medial to anterolateral but lateral to the ASIS-patella line; various points described	Similar to anterior portal	Lateral femoral cutaneous nerve, lateral femoral circumflex artery branches
Distal anterolateral portal	3-5 centimeters distal to the anterolateral portal	Access to peripheral compartment around femoral neck	lateral femoral circumflex artery branches
Posterolateral portal	1-2 cm posterior and proximal to the greater trochanter	Posterior access to hip joint	Sciatic nerve

1. Anterolateral portal

The anterolateral portal is usually created first, 1-2 cm anterior and proximal to the anterior/superior most aspect of the greater trochanter. Under fluoroscopy, the needle is directed toward the superior acetabular roof while staying away from the labrum and femoral-head cartilage. The anterolateral portal commonly holds the 70-degree arthroscope, and poor initial placement can make the remainder of the case difficult.

2. Anterior portal

The traditional anterior portal is an established central-compartment portal near the intersection of a vertical line from the ASIS and a horizontal line from the greater trochanter. Modern techniques often move this portal laterally or use a modified mid-anterior portal instead because the lateral femoral cutaneous nerve lies close to the traditional anterior portal.

3. Mid-anterior portal

The mid-anterior portal is commonly the second portal and is created under direct visualization through the anterolateral portal. The skin entry point is usually several fingerbreadths medial to the anterolateral portal but should remain lateral to the ASIS-patella line.

4. Distal anterolateral portal

The distal anterolateral portal is placed distal to the anterolateral portal by about 3-5 centimeters. It provides a favorable angle for drilling and anchor placement along the anterior and superior acetabular rim and is also useful for femoral head-neck and peripheral-compartment work.

5. Posterolateral portal

The posterolateral portal lies 1-2 centimeters posterior and proximal to the posterior superior aspect of the greater trochanter and provides posterior central- and peripheral-compartment access. The sciatic nerve is the major structure at risk, so the portal should remain close to the posterior border of the greater trochanter.

Accessory portals

Other described portals include proximal mid-anterior, proximal anterolateral accessory, peritrochanteric, and additional distal accessory portals. Accessory portals are created as needed to improve visualization and instrument trajectory. Proximal accessory portals tend to be useful for peripheral-compartment work, distal accessory portals can help with acetabular anchor placement and labral work and peritrochanteric portals provide access for bursectomy and other less common procedures.

References