4

 

 

P ITFALLS

• Absolute contraindications

  • Hip pain referred from other sources, such as a compression fracture of the lumbar spine

     

  • Osteonecrosis or synovitis in the absence of mechanical symptoms

     

  • Acute skin lesions or ulceration, especially in the vicinity of portal placement

     

  • Sepsis with accompanying osteomyelitis or abscess formation

     

  • Advanced osteoarthritis, grade III or IV heterotopic bone, joint ankylosis, and significant protrusion.

 

Hip Arthroscopy

 

Indications

• Labral tears

• Chondral lesions

• Loose bodies

• Synovial diseases: synovial chondromatosis, pigmented villonodular synovitis

• Trauma

• Crystalline diseases (gout, pseudogout)

• Previous total hip arthroplasty

• Early-stage osteonecrosis

• Symptomatic impingement

  Examination/Imaging

• Positive examination findings include a positive McCarthy sign; inguinal pain with flexion, adduction, and internal rotation; and inguinal pain with resisted straight leg-raising test.

  Controversies

  • Morbid obesity is a relative contraindication for arthroscopy, not only because of distraction limitations but also because of the requisite length of instruments necessary to access and maneuver within the deeply recessed joint.

  • Moderate dysplasia needs to be judiciously evaluated prior to arthroscopic intervention.

  • Candidates for hip arthroscopy should have reproducible symptoms and physical findings that limit function, along with a history of mechanical symptoms such as clicking, catching, locking, or buckling.

   

• Gadolinium-enhanced arthrogram magnetic resonance imaging may increase the diagnostic yield of intra-articular hip pathology, as shown by the labral tear evident in Figure 1 (arrow).

  Surgical Anatomy

• The deeply recessed femoral head lies within the bony acetabulum. The hip joint is enclosed within a thick fibrocapsular and muscular envelope in close proximity to the sciatic nerve, lateral femoral cutaneous nerve, and femoral neurovascular structures.

• Fluoroscopic images determine the relative distraction of the femoral head from the acetabulum (see accompanying video).

  Treatment Options

  • Lateral approach

  • Supine approach

   

  • The negative intra-articular pressure that results from the distraction force is released using a 6-inch, 18-gauge spinal needle with a Nytinol wire and an image intensifier if necessary. The needle is placed superior to the greater trochanter and tangential to the acetabulum, and a “give” sensation is felt upon capsule entry.

  • A second 6-inch, 18-gauge spinal needle is then advanced into the hip capsule, and then the joint is injected with approximately 30 to 40 ml of normal saline. Flow from the second spinal needle confirms intra-articular placement of both needles.

     

    Hip Arthroscopy

     

     

     

    5

     

    FIGURE 1

     

     

    6

     

     

    P EARLS

    • A tensiometer on the hip distraction device may be a significant help in preventing overzealous distraction.

       

    • Adequate distraction should be 8–10 mm for ease of instrument entrance.

       

    • General anesthesia with adequate skeletal muscle relaxation also reduces the force required to distract the hip.

       

    • The majority of hip arthroscopies can be done with distraction forces between 25 and 100 lbs of direct axial traction

       

      P ITFALLS

    • Adequate distraction is not only important for visualization but also to prevent scuffing of chondral surfaces.

       

    • Avoid continuous traction for more than 1 hour at a time.

       

    • Inadvertant loss of traction while instruments are in the joint may result in harm to the articular cartilage or instrument breakage within the joint.

     

    Hip Arthroscopy

     

    Positioning

• The lateral approach requires that the patient be positioned in the lateral decubitus position with the affected hip up. Most intra-articular lesions occur in the anterior quadrant of the hip and can be treated easily via the two primary portals of the lateral approach. Surgeons may use a modified fracture table, or a dedicated hip distractor can be positioned on a regular operating room table and adjusted in multiple planes (Fig. 2).

• Adequate distraction is required to separate the femoral head away from the acetabulum to allow passage of instruments into the recesses of the joint.

• A well-padded perineal post is positioned and adjusted prior to applying traction.

• Axial traction is applied via a carefully padded foot boot with the heel firmly seated and secured. The traction device is adjusted such that the foot can be maintained in neutral position with respect to eversion and/or inversion of the hindfoot, thereby avoiding undue stress to the ligamentous structures on one side or the other of the ankle.

• Distraction is applied with the leg abducted between 0° and 20°, depending on the patient’s neck shaft angle and the depth of the acetabulum. The hip then is placed in slight forward flexion of approximately 10–20°.

  Portals/Exposures

• Lateral approach (Fig. 3)

  Controversies

  • Surgeon preference for lateral vs. supine position.

   

  Equipment

  • Dedicated hip distractor is available through Innomed Corp (Savannah, GA).

   

  • The skin incisions are superficial, not penetrating deeper than the subcutaneous adipose tissue. Then, tapered blunt trocars are used to pass through the adipose, fascia, and muscle tissue. This technique protects all interceding neurovascular structures and muscle from sharp equipment and repetitive trauma during the

    exchange of instruments.

     

  • The pressure required varies by patient and by capsular location. A lens may be needed.

• Anterior superior paratrochanteric portal

  • The anterior superior paratrochanteric portal provides excellent visualization of the femoral head, anterior neck, anterior labrum, and synovial tissues beneath the zona orbicularis.

     

     

     

    7

     

    Hip Arthroscopy

     

    FIGURE 2

     

     

     

    FIGURE 3

     

    8

     

     

    P EARLS

    • The paratrochanteric portals pass through fewer muscle planes, avoid potential injury to the lateral femoral cutaneous nerve, and puncture the superior hip capsule, which is slightly thinner.

       

    • Image intensification is helpful to alter the position of the portal pathway. The posterolateral portal is considered a very safe portal. Placing this portal under direct visualization facilitates its intra-articular position. This is commonly done by placing the camera in the anterolateral portal first.

       

      P ITFALLS

    • The neurovascular structure that is at potential risk with the anterior superior paratrochanteric portal is the superior gluteal nerve. It is located 4–6 centimeters above the tip of the greater trochanter.

       

    • The initial trocar placement for the posterior superior paratrochanteric portal is slightly superior and slightly anterior to avoid deflection posteriorly and potential injury to the sciatic nerve. Positioning of the hip in flexion greater than 20° can translate the sciatic nerve anteriorly, bringing this structure into jeopardy. Likewise, external rotation of the femur posteriorly translates the greater trochanter and increases the likelihood of posterior deflection of the trocar, which may potentiate injury to the sciatic nerve. It is for this reason that the leg must be placed in neutral or slight internal rotation when passing the needle or trocar for this portal.

     

    Hip Arthroscopy

     

    In combination with the posterior superior trochanteric portal, it is an extremely useful portal for instrumentation and treatment of anterior labral lesions and acetabular chondral lesions.

  • The cannula is aimed toward the center of the acetabulum at the fovea while keeping it as close to the femoral head as possible.

  • This portal transgresses the anterior musculotendinous junction of the gluteus medius, the tendinous region of the gluteus minimus, and the anterior hip capsule before entering the joint.

• Posterior superior paratrochanteric portal

  • The posterior paratrochanteric portal is used to view the posterior capsule, posterior labrum, and the posterior femoral head.

     

    Instrumentation

    • The intra-articular structures in the hip joint can most often be visualized with a standard 30° arthroscope; however, there are times when a 70° arthroscope is benenficial.

    • Telescoping cannulas are extremely helpful for removal

      of large loose bodies or to accommodate angled punches.

    • A variety of probes and hooks are first used to evaluate the intra-articular structures.

    • A variety of long suction punches have been designed specifically for hip arthroscopy.

    • Extra-length mechanical shavers can also be useful for débridement of labral tears.

    • Curved shaver blades with either convex or concave surfaces improve navigation of the convex surface of the femoral head.

    • An unsheathed bur is helpful should bony resection be necessary.

    • Flexible thermal devices with precise control of temperature and coagulation are extremely useful in débriding chondral flaps and the torn labral rim.

     

     

    9

     

    Controversies

    • An important point with the posterolateral portal is that the “pop” that is encountered when entering the joint must be felt before bone is encountered. If bone is felt without the sensation of traversing the capsule, the trocar is either too high and the outer wall of the acetabulum is encountered, or too low and the head of the femur is encountered.

     

    Hip Arthroscopy

     

    • The entry point for this portal is placed at the junction of the posterior and middle thirds of the superior trochanteric ridge, essentially mirroring the anterior paratrochanteric portal.

    • Correct positioning of the posterior trochanteric portal passes through the posterior margin of the musculotendinous junction of the gluteus medius muscle.

Procedure

Step 1

 

P EARLS

• Flexible thermal devices with precise control of temperature and coagulation are extremely useful in débriding chondral flaps and the torn labral rim.

   

• Inflamed, redundant synovial tissue can also be resected and coagulated.

   

  P ITFALLS

• Over-resection of labral tissue should be avoided.

 

• Have a routine sequence for visualization of the central compartment.

• The labrum is an important anatomic structure in the hip joint with many functions; therefore, the least intrusive means of resecting or stabilizing a labral tear (Fig. 4, arrow) should be emphasized.

• Arthroscopic treatment of labral tears involves judicious débridement back to a stable base and to healthy-appearing tissue while preserving the capsular labral tissue.

 

 

 

 

FIGURE 4

 

10

 

 

 

Hip Arthroscopy

 

FIGURE 5

 

Instrumentation/ Implantation

• Labral tears are débrided with straight or curved extra-length shavers.

 

Step 2

• Chondral flaps require chondroplasty. If there is a full-thickness chondral defect (Fig. 5, arrow), the subchondral bone is drilled or treated with a microfracture technique to enhance fibrocartilage formation.

  Instrumentation/ Implantion

  • Chondral flaps are addressed using straight and curved shavers, angled basket forceps, and electrothermal tools with straight and flexible tips.

  • Microfracture of the chondral lesion may be done with straight or angled picks.

   

  Step 3

• Complete the procedure in the central compartment prior to examining the peripheral compartment.

• If surgery needs to be done in the peripheral compartment, traction is released and the hip is then flexed between 30° and 45°.

• Loose bodies are also sometimes found in the peripheral compartment (Fig. 6, arrow), and they can be removed from extra-articular spaces as well using fluoroscopic guidance.

   

  P EARLS

  • The central compartment should be addressed prior to the peripheral compartment.

   

  Postoperative Care and Expected Outcomes

• Most patients require crutches from 2 to 7 days. Patients may progress to full weight bearing as soon as comfort allows.

• Most patients are able to drive within 24–48 hours of the surgery.

 

11

 

 

P ITFALLS

• If resecting impinging bone or osteophytes, care must be taken to resect enough bone to address the problem without resecting too much bone, resulting in weakened bone integrity that may predispose to fracture.

   

• The posterior portion of the femoral head should not be resected in order to avoid compromising the blood supply and predisposing to avascular necrosis.

 

 

P EARLS

• Activity is gradually increased as comfort permits. This includes walking (not on a treadmill) or using a stationary bike or swimming once the stitches are removed.

   

  P ITFALLS

• Twisting and pivoting motions should be avoided for the first 6 weeks as they may produce sharp pain until postoperative swelling has subsided.

• Numbness in the perineum (including vagina or penis) or foot may occur that can last from a few days up to a few weeks. This distraction neurapraxia, like a knee tourniquet neurapraxia, resolves with time.

• Other activites to be avoided are use of the Nordic Track, Stair Master–type leg press machines, and deep squats.

 

 

 

Instrumentation/Implantation

• Loose bodies can be resected and simultaneously aspirated with a variety of long suction punches designed specifically for hip arthroscopy.

• Alternatively, a partial synovectomy can be done using straight and curved extra-length shavers.

• Impinging osteophytes can be resected with unhooded burrs under fluoroscopic guidance.

 

Hip Arthroscopy

 

FIGURE 6

 

12

 

Hip Arthroscopy

 

Evidence

Byrd JW. Hip arthroscopy utilizing the supine position. Arthroscopy. 1994;10:275–80.

 

The supine position in arthroscopic hip surgery is performed on a standard fracture table with fluoroscopy. Traction is used to distract the hip for introduction of the instruments. Three standard arthroscopic portals are routinely used.

 

Glick JM. Hip arthroscopy using the lateral approach. Instr Course Lect. 1988;37:223–31.

 

Hip arthroscopy provides complete visualization of the joint space using a direct lateral approach over the greater trochanter, with the patient in the lateral decubitus position. The involved leg is held in an abducted and flexed position with traction by pulleys hung overhead.

 

McCarthy JC, Lee JA. Acetabular dysplasia: a paradigm of arthroscopic examination of chondral injuries. Clin Orthop. 2002;122–8.

 

Mild uncovering of the anterior femoral head subjects the labrum to increased load and potential susceptibility to tearing most frequently anteriorly. The findings in the current study support the concept that labral disruption frequently is a predecessor in the continuum of degenerative joint disease.

 

McCarthy JC, Lee JA. Hip arthroscopy: indications, outcomes, and complications. Instr Course Lect. 2006;55:301–8.

 

Hip arthroscopy is technically demanding and requires special distraction tools and operating equipment. With proper patient selection hip arthroscopy can successfully manage numerous intra-articular conditions such as labral and chondral injuries, loose bodies, foreign bodies and synovial conditions.

 

McCarthy JC, Noble PC, Schuck MR, Wright J, Lee J. The Otto E. Aufranc Award: The role of labral lesions to development of early degenerative hip disease. Clin Orthop. 2001;25–37.

 

Arthroscopic and anatomic observations support the concept that labral disruption and degenerative joint disease are frequently part of a continuum of joint disease.