Arthroscopy of the hip is already a very important diagnostic and therapeutic tool for hip joint related pathology. Hip arthroscopy has a clear advantages over any other method of imaging currently available. Glick reported that it allowed a diagnosis to be made in 40% of cases of painful hips where all prior investigations had been normal!
Current indications for hip arthroscopy include removal of loose bodies, synovial biopsy, subtotal synovectomy, management of labral tears, synovial chondromatosis, osteochondritis dissecans, chondral lesions, or staging of chondral lesions, and the treatment of pyarthrosis.
Arthroscopic removal of bullet fragments from the hip, extraction of intraarticular cement, and impinging ligamentum teres have been reported. In adults, lavage and debridement for early stage septic arthritis can be performed. In paediatric patients, the small size of the joint and the close proximity of neurovascular structures make the procedure difficult to perform safely and adequately and is best avoided.
Common indications for Hip Arthroscopy
- Loose bodies
- Labral tears
- Chondral lesions of the acetabular or femoral head
- Osteonecrosis of the femoral head
- Ruptured or impinging ligamentum teres
- Dysplasia
- Synovial Abnormalities: Synovial chondromatosis, Hematologic disorders
- Infection
- After total hip arthroplasty (diagnosis of occult sepsis or removal of intra-articular wire or cement)
- After trauma (dislocation, Pipkin fracture, removal of foreign body)
- Osteoarthritis
- Extra-articular conditions
Approaches and Portals
Three standard portals are used for this procedure.
- Anterior
- Antero-lateral, and
- Postero-lateral
The antero-lateral portal is established first, using a 6-inch, 17-gauge needle under fluoroscopy. The portal is in the safe zone and penetrates the gluteus medius muscle with the superior gluteal nerve traversing approximately 4.4-cm cephalad to the portal.
To make the inferior portal and the postero-lateral portal, pass the spinal needle into the joint observing the needle and its position with a 70-degree arthroscope. Verify correct placement with fluoroscopy.
Place the anterior portal at the intersection of a line drawn from the anterosuperior iliac spine and a transverse line drawn from the superior margin of the greater trochanter, which when extended more medially is just superior to the top of the symphysis pubis. The anterior portal penetrates the sartorius and rectus femoris before entering the anterior capsule.
Procedure
After establishing the three portals, place the outflow in the postero-lateral portal. To view the acetabulum, labrum, and the femoral head from each of the three portals, alternate the 70-degree scope and 30-degree scope between the anterolateral and anterior portals.
Rotate the lens and internally and externally rotate the hip. The 70-degree scope is best for viewing the labrum and the periphery of the acetabulum and femoral head, and the 30-degree scope is used for viewing of the central portion of the acetabulum, femoral head, and superior portion of the acetabular fossa.
To perform arthroscopy in the lateral decubitus position, place the affected hip superior and abducted between 20 and 45 degrees and extend it.
- Use an image intensifier to evaluate traction and to guide instruments.
- Apply sufficient traction to create a space large enough to accommodate a 5-mm arthroscope and instruments.
- Prepare and drape the hip in a routine sterile manner to allow access as far anteriorly as the femoral artery and slightly past the posterior aspect of the greater trochanter.
- The average amount of traction necessary to distract the hip 8mm is 50 pounds.
- Mark the anatomical landmarks, including the femoral artery anteriorly, the antero-superior iliac spine, and the inguinal ligament, and outline the anterior, posterior, and superior portions of the greater trochanter.
Make two portals over the greater trochanter and a third portal directly anterior. At the anterior point over the superior edge of the greater trochanter, insert a 6-inch, 18-gauge spinal needle into the hip joint under image intensifier guidance.
Make a skin incision at the needle site and insert the arthroscope sheath with a sharp trocar in the same direction, again under image intensifier guidance. After the capsule has been penetrated, replace the sharp trocar with a blunt one and insert the sheath as far into the joint as possible. Place the inflow on the arthroscope.
Next, establish an anterior portal for inflow. Insert a spinal needle at a point where a sagittal line through the anterior iliac spine meets a horizontal line from the proximal tip of the greater trochanter. Angle the needle 45 degrees in the cephalad direction and 20 degrees medially, using the image intensifier and the arthroscope for guidance. Make a small skin incision at the needle site and insert a 5.25-inch inflow cannula.
Extra portals can be made at the posterosuperior corner of the greater trochanter or anywhere between the greater trochanter and the anterior portal. The arthroscope also can be changed among the different portals, and further exposure of the hip joint can be obtained by rotating the leg. Use of a 70- or 90-degree arthroscope is also recommended. Compared with the supine position in which the anterolateral portal is often used, the lateral position provides comfortable access to the hip joint via the para-trochanteric approach.
Special extra long arthroscopic instruments are required to ease insertion and to maintain the instrument’s position within the hip joint. Initial insertion of long spinal needles (6”, 16 gauge) allow release of the negative pressure vacuum phenomenon created with joint distraction and act as a guide for ideal portal
All arthroscopic instruments should be passed through sturdy metallic sheaths or cannulas long enough to traverse soft tissues surrounding the hip once a portal is made.
Most of the intra-articular structures in the hip joint can be seen by varying the angle of the arthroscope and the portals used. Furthermore, specialised arthroscopic working instruments, such as shavers, burrs, drills, and loose body retrievers need to be of appropriate length and diameter to traverse the soft-tissue envelope of the hip and allow manipulation within the hip joint.
Results
Reports by McCarthy et al. and O’Leary et al. have shown 85% and 91% respective improvement in hip pain and dysfunction with arthroscopic debridement of labral defects.
Good results also have been reported after arthroscopic debridement of loose bodies and chondral defects of the hip. O’Leary et al. reported 89% improvement in patients with chronic hip pain from previous Legg-Calve-Perthes disease. Arthroscopic debridement for osteoarthritis and avascular necrosis has shown results similar to arthroscopic debridement of other arthritic joints.
Yamamoto Y et al (2005) studied 32 hip joints with snapping hip syndrome. Plain radiography, hip arthrography, magnetic resonance imaging (MRI), and arthroscopy were performed in these patients and the findings were compared. Arthroscopic surgeries were conducted in the following cases and resolved the snappin