Endoscopic anatomy for hip arthroscopies. We need to know the anatomy in order to have a safe access to the hip and avoid complications. In the hip, from an arthroscopic point of view, we have four spaces or compartments. Two interarticular, the central compartment and the peripheral compartment, separated by the acetabular labyrinth, and two extraarticular, the peritocanteric space and the divluteal or subluteal space. The central compartment includes the acetabular fossa, ligamentum terres, lunate cartilage, and articular surface of the femoral head in the weight-bearing area. The acetabulum is hemispheric in shape and is partially covered at the weight-bearing surface by articular cartilage, creating a lunate-shaped cartilage configuration with the rim and non-rim portions. This is very important because we will have non-rim cartilage lesions, as you can see here, and rim cartilage lesions. At the anterior-posterior apex of the acetabular fossa within its lunate surface, appears an articular lesion immediately above the acetabular fossa, referred to as the escalate crease, is frequently seen. This is a normal variant, and we must not confuse it with early degenerative changes. The fissile scars and area devoid of articular surface extending in a linear fashion, demarcating the area of the old triradiate fissus. This should not be misinterpreted as an old fracture line. Another anatomical landmark is the psoas fossa. This is a normal group of indentation at 2, 3, or 8, 9 o'clock in the anterior rib of the acetabulum where the psoas crosses. Sometimes the psoas tend to indent the medial joint capsule at this point, as you can see here. At the anterior-inferior region of the acetabulum, there is a cavity of focal bone indentation, the acetabular notch, often referred to as the cotyloid fossa that contains the pulmonary and ligamentum teres and is sustained by the transverse ligament. The ligamentum teres or ligamentum capitis femoris is an interarticular ligament that attaches the head of the femur to the acetabulum. It is raised in the inferior part of the acetabular fossa and runs inferiorly and anteriorly across the joint space to insert into the fovea capitis of the head of the femur. The normal length is 32 millimeters, and it has a broad acetabular region attaching to both sides of the cotyloid notch with two fascicles, the ischiatic and the pubic fascicles. This ligament, as you can see here in this video, is tough in external rotation and lax in internal rotation. The anterior triangle, which is composed of the anterior capsule, anterior labrum, and femoral head, is a very powerful landmark and will give direct visualization of the spinal needle when establishing the anterior portal. At the free margin of the bony acetabulum, there is a fibrocartilage structure, the labrum, with increased depth and extension of the cotyloid fossa. Labrum is divided into capsular and articular sides. Capsular side is thicker and composed of dense connective tissue. Articular side is composed of type II collagen fibrocartilage. The sternal face of the acetabulum inserts under the joint capsule, leaving a free border. It is thicker superiorly and posteriorly than it is inferiorly and anteriorly. Although the acetabular labrum was described as an homogeneous ring-shaped structure, this posterior part can be bifurcated, as you can see in this illustration. The peripheral compartment, sorry, in some cases, we will find a sublateral sulcus beam, posterior inferior, the most frequent location. The peripheral compartment is full of the non-weight-bearing cartilage of the femoral head, femoral neck, synovial folds, and capsular and ligaments. There is usually a normal paravagal sulcus or peri-labral recess above the lateral labrum. This is another view of the peripheral compartment of the hip. This is the femoral head, the labrum, the peri-labral recess, femoral head, and this is the sun orbicularis. Another view of the femoral neck, the femoral head, the sun orbicularis, it is the circular fibrous extension of the femoral ligament. The medial fold is an important reference for initial orientation, and usually indicates the medial limit for performing osteochondroplasty in cases of femoral acetabular impingement. Usually, it's not adherent to the femoral neck and passes approximately from the medial border of the femoral head distally to the lesser trochanter. The lateral folds have been called alike a structure representing branches of the medial femoral circumflex artery to the inferior portion of the femoral head. This structure marks the end point of trimming of the femoral head and neck action for femoral acetabular impingement surgery. During this fold, subia voicus contains important vessels for vascular supply of the femoral head. Another normal variant is an anterior capsule called direct contact to psoas tendon. We will find in 15 to 20% of cases, and it has no pathologic relevance and is a drainage of the person. As you can see here, there is a hole, and in this case, this is a normal structure, but it has just some lesion in an impingement of the labrum or the tendon. The peritrochanteric compartment. The borders of the peritrochanteric compartment consist of the tensor fasciae latae and iliotibial band laterally, the abductor tendons superior medially, the vastus lateralis inferior medially, the gluteus maximus muscle superiorly, and each tendon posteriorly. We approach this stage with an all-in-side technique and this is the view of the insertion of the gluteus max tendon. For me, this is the lighthouse in this space, running posterior to the vastus lateralis into the linear aspera. This is the gross anatomy of the gluteus medius and minimus muscle tendon units of the right hip. I recommend this chapter in the techniques in orthopedics to review this anatomy. This video shows different endoscopic views of the peritrochanteric space. You can see here, we identify the vastus lateralis, some fatty tissue near the sciatica nerve, vastus gluteus maximus link, and in this case, gluteus maximus link, and here we will find the iliotibial band which have received changes in asymptomatic coxa saltan externs. You can see here. Fibrous bands and bursa from the trochanteric bursa may need to be removed in order to best visualize the medius attachment to the greater trochanter. Now we will focus on posterior or subgluteal space anatomy. Subgluteal space is the cellular and fatty tissue situated between the middle and deep gluteal aponeurosis layers. First, we must know the gross anatomy, and I recommend the book from Hal Martin and Gomez de Hoyos, Posterior Hip Pain. Once in the peritrochanteric space, just above the gluteal link, we make a window to access the subgluteal space, then localize the quadratus and find the sciatic nerve distal to the quadratus, which is the sciatic quadratus, and this is the call we do to enter this space. This is the quadratus, sciatic, and the relationship between them. Distally, we must identify the ischial tunnel, and we usually do distal decompression before any proximal work. You must inspect this tunnel, and you must release any fibrous from the sciatic nerve to the tendons nearby. Check sciatic nerve vascularity. Normal sciatic nerve will have noticeable epineural blood flow and epineural fat, whereas an abnormal sciatic nerve will appear white, lacking epineural blood flow, as you can see here, normal and normal. Then periformis muscle and tendon is identified proximally. You can see here the sciatic nerve, the tendon of the periformis, and the muscle. So you might pay constant attention to the branches of the inferior gluteal artery, which are in vicinity of the periformis muscle. As you can see here, in the case of periformis syndrome and trauma of the sciatic nerve, the tendon, muscle, tendon, muscle, sciatic nerve, the branches of the inferior gluteal artery nearby, and this is the tendon of the periformis. The possible variations of anatomical relationship between the periformis muscle and the sciatic nerve should be identified. This is the Beton and Anson classification. Fibrovascular bands must be identified and released. This is a band, fibrovascular band. This is pierced in the sciatic nerve, and this is a vascular band. This is an endoscopy view showing a tight view of Beton. Before the identification of the sciatic branches, look at the sciatic nerve is passing through the periformis. After the section, a divided sciatic nerve passing through and below the periformis muscle is identified. This will be the peroneum branch, and this is the tibial branch, superior periformis and inferior periformis. At the sciatic notch, this is another endoscopic view and then after releasing some vascular bands, and this is an important structure. This is the inferior gluteal nerve. This is the sciatic nerve, and as we see, it has two components just near the sciatic notch. This is the peroneal branch, and this is the tibial branch. Insertional pathology and variations concerning sciatic nerve and osteoarthritic gemelli complex are also possible being the most frequent and osteoarthritic internals penetrating the nerve. We must know the anatomy for hamstring surgery and also for endoscopy, open or endoscopy. You can see here the gross anatomy and the endoscopic anatomy is very similar. The sciatic nerve is close to the ischial tuberosity. This is the sacrotuberous ligament, hamstrings, the ischial tuberosity, and the quadratus insertion into the ischial tuberosity. We must know also the anatomy of the ischiofemoral space. The lesser trochanter can be approached through a small window in the quadratus femoris muscle. This window is located between the medial fifth complex femoral artery, proximal, and first perforating femoral artery distal. The proximal and distal edges of the muscle should be preserved in order to avoid injury to this arteries. This is the space that we get at the end of this surgery, 17 millimeters between the nerve and the lesser trochanter. And this is another view of endoscopic decompression of ischiofemoral impingement syndrome. Thank you very much, and thank you, Ana, for giving me this opportunity to present our videos and illustrations.

endoscopic anatomy

hip arthroscopies

central compartment

peripheral compartment

anatomical variations