Operative Hip Arthroscopy - part 5 doc

ter it takes off from the femoral artery (see Figure 6.6). The ascending branch of the lateral circumflex femoral artery has an oblique course along the direction of the intertrochanteric line. The superior gluteal nerve and artery are the most superior of 10 neurovascular structures that exit through the sciatic notch (Figure 6.7). They course transversely in a posterior to anterior direction between the deep surface of the gluteus medius and the superficial surface of the gluteus minimus, innervat- ing and supplying blood to both. The sciatic nerve ex- its the notch under the piriformis tendon and then lies posterior to the other short external rotators in a ver- tical direction as it courses distally (see Figure 6.7). An intricate vascular anastomosis converges at the lower border of the quadratus femoris consisting of the ascending branch of the first perforating artery, the descending branch of the inferior gluteal artery, and transverse branches of the medial and lateral circumflex femoral arteries (see Figure 6.7). CAPSULAR AND JOINT ARCHITECTURE The ilium, ischium, and pubic bones unite at the acetabulum, forming the innominate bone. During childhood, these bones are separated within the acetabulum by the triradiate cartilage, which fuses at skeletal maturity. The acetabulum has an inclined abduction angle of approximately 35 degrees from the horizontal and a forward flexed position of approximately 20 degrees (Figure 6.8A,C). The articular surface of the acetabulum has a horseshoe or lunate shape (Figure 6.9). The central inferior acetabular fossa is devoid of articular surface. It is occupied by a fat pad cov- ered with synovium called the pulvinar. Addition- ally, it contains the acetabular attachment of the ligamentum teres. The socket of the acetabulum is completed inferiorly by the transverse acetabular ligament. 104 J .W . THOMAS BYRD Iliacus muscle Lateral femoral cutaneous nerve Ascending branch of the lateral circumflex femoral artery Psoas major muscle Iliopsoas muscle Femoral nerve artery & vein FIGURE 6.6. Neurovascular structures (anterior view). CHAPTER 6: GROSS ANATOMY 105 Descending branch of inferior gluteal artery 1st perforating artery Superior gluteal nerve & artery Inferior gluteal nerve & artery Pudendal nerve Posterior femoral cutaneous nerve Sciatic nerve Medial circumflex femoral artery FIGURE 6.7. Neurovascular structures (posterior view). FIGURE 6.8. (A) Acetabular orientation averages 35 degrees of abduction from the horizontal plane. The neck shaft angle formed between the axis of the femoral neck and femoral shaft averages 125 degrees. (B) Femoral anteversion, determined by the angle created between the bicondylar axis of the knee and the axis of the femoral neck in the transverse plane, averages 14 degrees. (C) The acetabulum is also oriented with 20 degrees of forward flexion relative to the sagittal plane. The labrum is a fibrocartilaginous structure that attaches to the bony rim of the acetabulum, effectively deepening to a socket. The labrum terminates inferiorly at the anterior and posterior margins of the acetabular fossa. It then becomes contiguous with the transverse acetabular ligament, which completes the circumferential ring of the acetabulum. We are learn- ing that the labrum is a nonhomogeneous structure with considerable variation in different areas of the acetabulum (see Chapter 8). Although variable, the proximal femur has a neck shaft angle that averages 125 degrees, with approximately 14 degrees of femoral neck anteversion (see Figure 6.8A,B). The femoral head has an articular surface that forms approximately two-thirds of a sphere, articulating with the acetabulum (see Figure 6.9). Me- dially, on the articular portion of the femoral head, is a pit called the fovea capitis, the site of the femoral attachments of the ligamentum teres. The bony architecture of the hip provides it with significant intrinsic stability. This stability is further enhanced by an intricate complex of capsular ligaments. This complex consists of four distinct ligaments that provide varying contributions to the joint. The intricate nature and specific design of the capsular ligaments has been well defined by various anatomic studies. However, over time, more will be learned about the ligaments as a better appreciation is gained of the arthroscopic appearance of this anatomy. Perhaps this construct will even be partially redefined. Anteriorly, the capsule consists primarily of the iliofemoral ligament or ligament of Bigelow (Figure 6.10). It has an inverted Y shape beginning from its iliac attachment on the superior aspect of the acetabulum. It then fans out in a spiraling pattern to its femoral attachment along the intertrochanteric line. It is one of the strongest ligaments in the body, and the spiraling direction of its fibers makes it taut in extension in a wringing-out mechanism and relaxed in flexion. The ischiofemoral ligament reinforces the posterior capsule (Figure 6.11). It too has a spiraling pattern as it courses from its ischial attachment on the posterior acetabular rim to its femoral attachment on the superolateral neck, medial to the base of the greater trochanter. The pubofemoral ligament, although relatively weak, reinforces the inferior and anterior capsule from 106 J .W . THOMAS BYRD Lunate articular surface Labrum Acetabular fossa Transverse acetabular ligament Ischium Pubis Fovea capitis Ligamentum teres Ilium FIGURE 6.9. Formed from portions of the ilium, ischium, and pubis, the lunate-shaped articular surface of the acetabulum surrounds the fossa contain- ing the acetabular attachment of the ligamentum teres and fat, both encased in synovium. The labrum effectively deepens the socket and is contiguous with the transverse acetabular ligament inferiorly. The articular surface of the femoral head forms approximately two- thirds of a sphere. Medially, the ligamentum teres attaches at the fovea capitis. The diameter of the femoral neck is only 65% of the diameter of the femoral head, which allows for freer range of motion without marginal impingement. CHAPTER 6: GROSS ANATOMY 107 Pubofemoral ligament Iliofemoral ligament ANTERIOR FIGURE 6.10. The iliofemoral ligament (ligament of Bigelow) has the shape of an inverted Y as it spirals from its attachment on the iliac portion of the superior acetabulum to its femoral attachment on the anterior neck. It is quite powerful and becomes taut in extension. The relatively weak pubofemoral ligament reinforces the inferior and anterior capsule, where it blends with the medial edge of the iliofemoral ligament. Ischiofemoral ligament POSTERIOR FIGURE 6.11. The ischiofemoral ligament reinforces the posterior capsule, spiraling from its attachment on the ischial portion of the posterior acetabulum to the superolateral aspect of the femoral neck. the pubic part of the acetabular rim where it blends with the medial edge of the iliofemoral ligament (see Figure 6.10). Again, the spiraling nature of this complex tends to screw the femoral head medially into the acetabulum during extension, which has several clinical implications. First, this explains why patients with an irritable hip, whether the result of trauma, disease, or infection, tend to rest with the hip in a slightly flexed position, relaxing the capsule. Second, from a surgical standpoint, it would appear advanta- geous to perform arthroscopy with the hip flexed, further relaxing the capsule. However, this can create po- tential concern for portal placement, as discussed in Chapter 7. The fourth ligament is the ligament of the head of the femur (ligamentum teres) (Figure 6.12). Coursing from its attachment in the acetabular fossa to the fovea of the femoral head, it is intracapsular, yet encased in synovium, making it extrasynovial. Its relatively weak, redundant nature makes it unlikely that this has any significant stabilizing effect on the hip. The size and strength of this ligament are variable, and it is occasionally absent, the significance of which is unknown. A deep layer of fibers within the ligamentous capsule courses circularly around the neck of the femur, creating the zona orbicularis (see Figure 6.12). This layer may serve as a collar to constrict the capsule and help maintain the femoral head within the acetabulum. VASCULAR SUPPLY TO THE FEMORAL HEAD Intraarticular isolation of the femoral head and neck makes it highly dependent on its tenuous vascular supply. Its susceptibility to circulatory compromise is an ongoing source of concern to physicians who treat hip pathology. Ischemic insult followed by avascular necrosis (AVN) of the femoral head, similar to other forms of osteonecrosis, has been clearly linked to cer- tain disease states and types of exposure although it is less clearly associated with others and often purely idiopathic. 10 AVN has been associated with previous trauma including fracture and dislocation and may occur iatrogenically in association with surgical procedures that violate the vascular pattern. 108 J .W . THOMAS BYRD Ligamentum teres Zona orbicularis FIGURE 6.12. The ligamentum teres is redundant and weak and contributes little to the capsular stability of the hip. Encased in synovium, it is intracapsular, yet extrasynovial. The poorly defined and uncertain nature of AVN is reflected in the myriad surgical procedures that have been described in its management, none of which has proven to be superior, and few of which have even been shown to be truly effective in altering the natu- ral course of the process. 11 Arterial blood supply to the femoral head is achieved through an anastomosis of three sets of arteries (Figure 6.13). The principal vessels ascend in the synovial retinaculum, which is a reflection of the ligamentous capsule onto the neck of the femur. These vessels arise mainly posterior superiorly and posterior inferiorly from the medial circumflex femoral artery, which is supplemented to a lesser extent from the lateral circumflex femoral artery. These vessels anasto- mose with the terminal branches of the medullary artery from the shaft of the femur. The third source is the anastomosis within the femoral head from the artery of the ligamentum teres, which arises from a posterior division of the obturator artery. This vessel may persist with advanced age, but in approximately 20% of the population it never develops. References 1. Anderson JE: Grant’s Atlas of Anatomy, 7th ed. Baltimore: Williams & Wilkins, 1978. 2. Hoppenfeld S, deBoer P (eds): Surgical Exposures in Or- thopaedics. The Anatomic Approach. Philadelphia: Lippincott, 1984. 3. Byrd JWT: Hip arthroscopy utilizing the supine position. Ar- throscopy 1994;10:275–280. 4. Byrd JWT, Pappas JN, Pedley MJ: Hip arthroscopy: an anatomic study of portal placement and relationship to the extra- articular structures. Arthroscopy 1995;11:418–423. 5. Glick JM: Hip arthroscopy using the lateral approach. Instr Course Lect 1988;37:223–231. 6. Johnson L: Hip joint. In: Johnson L (ed). Diagnostic and Surgi- cal Arthroscopy, 3rd ed. St. Louis: Mosby, 1986:1491–1519. 7. Ide T, Akamatsu N, Nakajima I: Arthroscopic surgery of the hip joint. Arthroscopy 1991;7:204–211. 8. Henry AK: Extensile Exposure, 2nd ed. New York: Churchill Livingstone, 1973. 9. Gross RH: Arthroscopy in hip disorders in children. Orthop Rev 1977;6:43–49. 10. Jones JP: Concepts of etiology and early pathogenesis of osteonecrosis. Instr Course Lect 1994;43:499–512. 11. Steinberg ME: Early diagnosis, evaluation and staging of osteonecrosis. Instr Course Lect 1994;43:513–518. CHAPTER 6: GROSS ANATOMY 109 Artery of ligamentum teres (foveolar artery) Medial circumflex femoral artery Deep femoral artery Retinacular arteries superior anterior/posterior inferior Ascending transverse & descending branches of the lateral circumflex femoral artery FIGURE 6.13. The femoral head receives arterial blood flow from an anastomosis of three sets of arteries: (1) the retinacular vessels, primarily from the medial circumflex femoral artery and, to a lesser extent, the lateral circumflex femoral artery; (2) terminal branches of the medullary artery from the shaft of the femur; and (3) the artery of the ligamentum teres from the posterior division of the obturator artery. 110 7 Portal Anatomy J.W. Thomas Byrd T here has been much variation, as well as pre- cision, in the description in the literature of portal placements for hip arthroscopy. The at- tention given to these detailed descriptions is impor- tant for two reasons: (1) accessibility of the joint and (2) avoidance of the major surrounding neurovascular structures. The tip of the greater trochanter is the common landmark used in describing a variety of lateral portals. 1–3 Equal variation can be found in the description of an anterior portal (Figure 7.1). Eriksson et al., 4 Frich et al., 5 and Gross 6 base the portal lateral to the femoral pulse. Ide et al. 7 describe an anterior portal 1 cm lateral and distal to the midpoint of a line between the anterior superior iliac spine and the symphysis pubis. Johnson 8 also describes the symphysis pubis as a landmark, positioning a portal at the site of intersection of a sagittal line drawn distally from the anterior superior iliac spine and a transverse line drawn laterally from the pubic symphysis. Dorfmann et al., 9 follow- ing a cadaveric study, were most comfortable with a portal inserted midway along a line between the anterior superior iliac spine and the superior tip of the greater trochanter. Conversely, Glick et al. 10 describe an anterior portal at the site of intersection of a sagittal line drawn distally from the anterior superior iliac spine and a transverse line across the tip of the greater trochanter. Similarly, Watanabe 11 describes the same approach in his text on arthroscopy of small joints. A medial approach was also described by Gross, 6 appli- cable in the pediatric population with hip dysplasia. I use three standard arthroscopy portals (Figure 7.2). 12 Two of these are placed laterally (anterolateral and posterolateral) over the superior margin of the greater trochanter and can effectively enter the hip under direct fluoroscopic control. Positioning of the anterior portal requires more triangulation technique. Herein are described the three standard portals that I use for hip arthroscopy (see Chapter 11) and the specific anatomic relationship of the major structures to these portals (Table 7.1). 13 All three portals are routinely established for each arthroscopic procedure and usually found to provide adequate accessibility of the joint. If, however, an al- ternative portal is necessary, knowing the anatomic relationship of the extraarticular structures to these index portals should be helpful in safely establishing supplemental entry sites. ANTERIOR PORTAL The anterior portal is established by drawing a sagittal line distally from the anterior superior iliac spine and a tranverse line from the superior margin of the greater trochanter (see Figure 7.2). The intersection of these two lines marks the site of the anterior portal. The portal must be directed approximately 45 degrees cephalad and 30 degrees toward the midline. In the clinical setting, this is performed under fluoroscopic control as well as direct visualization through the arthroscope from the anterolateral portal, which is established first for introduction of the arthroscope. The anterior portal lies an average of 6.3 cm distal to the anterior superior iliac spine. It penetrates the muscle belly of the sartorius and the rectus femoris before entering through the anterior capsule (Figure 7.3). Typically, the lateral femoral cutaneous nerve is divided into three or more branches at the level of the anterior portal. The portal passes within several millimeters of one of these branches, usually the most medial branch (Figure 7.4). Consequently, moving the portal more laterally, a maneuver that has occasionally been described for avoidance of the lateral femoral cutaneous nerve, is ineffective. It simply places the portal more within the remaining branches of the nerve. In fact, moving the portal more medially would more effectively avoid the lateral femoral cutaneous nerve, but this maneuver would be ill advised because of the increasingly closer proximity of the femoral nerve. Because of the multiple branches, the lateral femoral cutaneous nerve is not easily avoided by altering the portal position, but it is protected by using meticulous technique in portal placement. Specifi- cally, it is most vulnerable to a skin incision placed too deeply, lacerating one of the branches. Passing from the skin to the capsule, the anterior portal runs almost tangential to the axis of the femoral nerve and lies only slightly closer at the level of the capsule with an average minimum distance of 3.2 cm (Figure 7.5). Although variable in its relationship, the ascending branch of the lateral circumflex femoral artery is usually approximately 3.7 cm inferior to the anterior portal (Figure 7.6). In some cadaver specimens, a small terminal branch of this vessel has been identified ly- ing within millimeters of the portal at the level of the capsule. The clinical significance of this is uncertain, and there have been no reported cases of excessive bleeding from the anterior position. ANTEROLATERAL PORTAL The anterolateral portal lies most centrally in the safe zone for arthroscopy and thus is the portal established first for introduction of the arthroscope. It is positioned directly over the superior margin of the greater trochanter at its anterior border (see Figure 7.2). Ac- counting for the slightly anterior position of the femoral head resulting from femoral neck anteversion, this allows a relatively straight shot into the hip joint under fluoroscopic guidance in the anteroposterior (AP) plane. Care should be taken during portal placement to assure neutral rotation of the hip because excessive internal or external rotation alters the relationship of the greater trochanter with the femoral head. The anterolateral portal penetrates the gluteus medius before entering the lateral aspect of the cap- CHAPTER 7: PORTAL ANATOMY 111 Anterior superior iliac spine Femoral pulse Pubic symphysis Greater trochanter A B DE C Anterior Portal Anterolateral Portal Posterolateral Portal FIGURE 7.1. Various descriptions of an anterior portal have been proposed: (A) based lateral to the femoral pulse; (B) 1 cm lateral and distal to the midpoint of a line between the anterior superior iliac spine (ASIS) and symphysis pubis; (C) site of intersection of a sagittal line from the ASIS and a transverse line from the symphysis pubis; (D) midpoint of a line between the ASIS and superior tip of the greater trochanter; (E) intersection of a sagittal line from the ASIS and a transverse line from the tip of the greater trochanter. Note: I strongly discourage consideration of the portal described in B; this does not appear to represent a safe approach to the joint. Also, note that palpation of the femoral pulse as a landmark can be difficult once the surgical field has been sterilely prepared. FIGURE 7.2. The site of the anterior portal coincides with the intersection of a sagittal line drawn distally from the anterior superior iliac spine and a transverse line across the superior margin of the greater trochanter. The direction of this portal courses approximately 45 degrees cephalad and 30 degrees toward the midline. The anterolateral and posterolateral portals are positioned directly over the superior aspect of the trochanter at its anterior and posterior borders. (Courtesy of Smith & Nephew Endoscopy, Andover, MA.) 112 J .W . THOMAS BYRD TABLE 7.1. Distance from Portal to Anatomic Structures Based on an Anatomic Dissection of Portal Placements in Eight Fresh Cadaver Specimens). Portal Anatomic structure Average (cm) Range (cm) Anterior superior iliac spine 6.3 6.0–7.0 Lateral femoral cutaneous nerve a 0.3 0.2–1.0 Anterior Femoral nerve (level of sartorius) b 4.3 3.8–5.0 Femoral nerve (level of rectus femoris) 3.8 2.7–5.0 Femoral nerve (level of capsule) 3.7 2.9–5.0 Ascending branch of lateral circumflex femoral artery 3.7 1.0–6.0 c Terminal branch 0.3 0.2–0.4 Anterolateral Superior gluteal nerve 4.4 3.2–5.5 Posterolateral Sciatic nerve 2.9 2.0–4.3 a Nerve had divided into three or more branches and measurement was made to the closest branch. b Measurement made at superficial branch of sartorius, rectus femoris, and capsule. c Small terminal branch of ascending branch of lateral circumflex femoral artery identified in three specimens. Source: From Byrd et al., 13 with permission of Arthroscopy. FIGURE 7.4. The relationship of the anterior portal to the multiple branches of the lateral femoral cutaneous nerve is shown. Multiple branches at the level of the portal are character- istic, and the branches always extend lateral to the portal. (Reprinted with permission from Byrd et al. 13 ) FIGURE 7.3. Anterior portal pathway/relationship to lateral femoral cutaneous nerve, femoral nerve, and lateral circumflex femoral artery. (Courtesy of Smith & Nephew Endoscopy, Andover, MA.) sule at its anterior margin (Figure 7.7). The structure of most significance relative to this portal is the superior gluteal nerve (Figure 7.8). After exiting the sciatic notch, the superior gluteal nerve courses transversely posterior to anterior across the deep surface of the gluteus medius. Its relationship is the same with both the lateral portals, with an average distance of 4.4 cm. 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. Maintain- ing 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 gluteus 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 (Fig- ure 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 CHAPTER 7: PORTAL ANATOMY 113 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 7.5. The femoral nerve (n) lies lateral to the femoral artery (a) and vein (v). The relationship of the anterior portal as it pierces the sartorius is shown. (Reprinted with permission from Byrd et al. 13 ) [...]... Ogaku Shoin, 19 85 12 Byrd JWT: Hip arthroscopy utilizing the supine position Arthroscopy 1994;10:2 75 280 13 Byrd JWT, Pappas JN, Pedley MJ: Hip arthroscopy: an anatomic study of portal placement and relationship to the extra-articular structures Arthroscopy 19 95; 11:418– 423 14 McCarthy JC, Day B, Busconi B: Hip arthroscopy: applications and technique J Am Acad Orthop Surg 19 95; 3:1 15 122 8 Arthroscopic... 1979;60A :57 5 58 5 2 Hisaw FL: Experimental relaxation of the pubic ligaments in the guinea pig Proc Soc Exp Biol Med 1921;23:661–689 3 Wilkinson JS: Prime factors in the aetiology of congenital dislocation of the hip J Bone Joint Surg 1963;45B:268–2 85 4 Takechi H, Nagashima H, Ito S: Intra-articular pressure of the hip joint outside and inside the labrum J Jpn Orthop Assoc 1982 ;56 :52 9 53 6 5 Horii M,... the hip joint Arthroscopy 1991;7:204–211 8 Johnson L: Hip joint In: Johnson L (ed) Diagnostic and Surgical Arthroscopy, 3rd ed St Louis Mosby, 1986:1491– 151 9 9 Dorfmann H, Boyer T, Henry P, DeBie P: A simple approach to hip arthroscopy Arthroscopy 1988;4:141–142 10 Glick JM, Sampson TG, Gordon RB, Behr JT, Schmidt E: Hip arthroscopy by the lateral approach Arthroscopy 1987;3:4–12 11 Watanabe M: Arthroscopy. .. Scand 1934; 75: 1 85 196 Gray’s Anatomy, 37th ed New York: Longman, 1989 :51 8 52 6 Gray AJR, Villar R: The ligamentum teres of the hip: an arthroscopic classification of its pathology Arthroscopy 1997;13: 57 5 57 8 Dvorak M, Duncan CP, Day B: Arthroscopic anatomy of the hip Arthroscopy 1990;6:264–273 Noriyasu S, Suzuki T, Sato E, et al: On the morphology and frequency of Weitbrecht’s retinacula in the hip joint... adult hip joints: an anatomic study in cadavera Am J Orthop 2001;30:809–812 13 Glick JM: Hip arthroscopy In: McGinty JB (ed) Operative Arthroscopy New York: Raven Press, 1991:663–676 14 Suzuki S, Kasahara Y, Seto Y, et al: Arthroscopy in nineteen children with Perthés disease: pathologic changes of the syn- 18 19 20 21 22 23 24 25 26 27 28 29 30 31 ovium and the joint surface Acta Orthop Scand 1994; 65: 581–... Mogensen B, Lidgren L: Arthroscopy of the hip in juvenile chronic arthritis J Pediatr Orthop 1981;1:273–278 4 Eriksson E, Arvidsson I, Arvidsson H: Diagnostic and operative arthroscopy of the hip Orthopaedics 1986;9:169–176 5 Frich LH, Lauritzen J, Juhl M: Arthroscopy in diagnosis and treatment of hip disorders Orthopaedics 1989;12:389– 391 116 J.W THOMAS BYRD 6 Gross RH: Arthroscopy in hip disorders in... Surg [Br] 1990;72:7 65 769 Klaue K, Durnin CW, Ganz R: The acetabular rim syndrome A clinical presentation of dysplasia of the hip J Bone J Surg [Br] 1991;73:423–429 Suzuki S, Awaya G, Okada Y, et al: Arthroscopic diagnosis of ruptured acetabular labrum Acta Orthop Scand 1986 ;57 :51 3– 51 5 Edward D, Lomas D, Villar RN: Comparison of MRI and hip arthroscopy in diagnosis of disorders of the hip joint J Bone... remember the specific hip position at the time of injury of the labrum associated with aging have been reported by Ueo and coauthors.16 This group accounts for 48.6% of the labral tears in the experience of Lage and coauthors.11 In a relatively recent publication, Seldes and coauthors10 studied 55 embalmed and 12 fresh-frozen adult hips with a mean age of 78 years Of these, 96% (53 of 55 ) had labral tears,... hip osteoarthritis Orthopedics 1999;22:4 05 409 9 Villar RN: Hip Arthroscopy, vol 5 Oxford: ButterworthHeinemann, 1992 :52 9 53 6 10 Seldes RM, Tan V, Hunt J, et al: Anatomy, histologic features, and vascularity of the adult acetabular labrum Clin Orthop 2001;382:232–240 11 Lage AL, Patel JV, Villar RN: The acetabular labral tear: an arthroscopic classification Arthroscopy 1996;12:269–272 12 Tan V, Seldes... acquired condition that is highly prevalent in aging adult hips Labral tears occur early in the arthritic process of the hip and maybe one of the causes of degenerative hip disease IDIOPATHIC No degenerative change, and no history of previous injury, can be present for a labral tear to be classified in this group Fitzgerald 15 reported that 25 of 55 of his patients (46%) had no previous history of trauma, . Pappas JN, Pedley MJ: Hip arthroscopy: an anatomic study of portal placement and relationship to the extra- articular structures. Arthroscopy 19 95; 11:418–423. 5. Glick JM: Hip arthroscopy using the. Ar- throscopy 1994;10:2 75 280. 13. Byrd JWT, Pappas JN, Pedley MJ: Hip arthroscopy: an anatomic study of portal placement and relationship to the extra-articular structures. Arthroscopy 19 95; 11:418– 423. 14 relatively recent publication, Seldes and coauthors 10 studied 55 embalmed and 12 fresh-frozen adult hips with a mean age of 78 years. Of these, 96% (53 of 55 ) had labral tears, with 74% of the tears

Định dạng
Số trang	29
Dung lượng	2,08 MB