PATH® Technique General Precautions

Patient Positioning	Neck Resection
Skin Incision	Portal Placement
Deep Dissection	Cup Impaction
Piriformis / Conjoined Tendon Release	Stem Impaction

Piriformis / Conjoined Tendon Release
A Blunt Hohmann (2007005) retractor is placed just above the piriformis/conjoined tendon, and deep to the capsular minimus muscle. Care is taken to not pull firmly on the Hohmann, as this may cause unnecessary trauma to the capsular minimus muscle. The piriformis tendon is released as close to its insertion onto the greater trochanter as possible.

Care is taken to preserve maximum piriformis tendon length. Approximately 1-2 cm of additional piriformis tendon length is typically present beyond the posterior edge of the greater trochanter. Bending the bovie at this point assists in maximizing piriformis tendon length. After release of the piriformis tendon, soft tissue attachments to the underlying capsule can be further released using the bovie or blunt dissection. The capsule is visible beneath the piriformis tendon, as is the upper edge of the obturator internus tendon.

The capsular incision is made parallel to the obturator internus tendon at its upper edge, parallel also to the neck axis. A cut is made from the intertrochanteric line to the rim of the acetabulum, at which point it is then turned proximally into a hockey stick or "J" orientation along the posterior acetabular edge. The intertrochanteric attachments are released over a length of approximately 8-10 mm proximally and distally. Care is taken not to release the remaining short external rotators. The distal capsular insertion on the posterior femoral neck does not extend very far, therefore only minimal distal capsular release is required. The hip is adducted, flexed and maximally internally rotated to facilitate dislocation.

After dislocation, the Anterior Acetabular Retractor (20070002 or 20070112) is placed along the inferior neck and a standard Hohmann is placed along the superior neck. This retractor placement is typically approximately 1 cm proximal to the low end of the skin incision. The hip is typically in 45° of flexion and 60°-70° of internal rotation as the neck is cut.

Neck Resection
Soft tissue (short external rotator) is visible on the femoral neck. The neck cut is started using a narrow oscillating saw blade, with the retractors protecting the skin edges. The oscillating saw is oriented approximately 45° to the long axis of the femur and in as close to neutral version as possible (beveling this cut into a small amount of anteversion does not pose a problem when using collarless implants).

After cutting through the center of the femoral neck, penetrating the anterior cortex with the oscillating saw blade, a reciprocating saw blade is utilized in an effort to minimize skin trauma, completing the resection from inside to outside on both sides. Once the cut is completed, a Schanz Screw (20070051 or 20070057) is passed into the center of the femoral head and the head is removed.

The leg is allowed to return to approximately 30° flexion, 20° adduction and approximately 30° internal rotation. The Anterior Acetabular Retractor (20070002 or 20070112) is placed along the anterior acetabular rim, adjacent to the anterior inferior spine at approximately 10-11 o'clock in the left hip and approximately 1-2 o’clock in the right hip. It is secured just over the bony rim and should not lever on the gluteus muscle, but on the tip of the greater trochanter (tilting approx 30° toward the foot of the patient). This retractor may require adjustment during the course of the operation.

A narrow Hohmann retractor is placed at the 12 o'clock position above the labrum and just inside the capsule. A small amount of dissection using a bovie or curved half-inch osteotome will facilitate separation of the labrum and the capsule. This provides a shelf for placement of an angled Hohmann or, in most cases, a 1/8 inch Steinmann pin. The pin is placed above the lateral rim of the acetabulum, but directed proximally to avoid interference during reaming. The pin is then bent at a 90° angle to act as a temporarily fixed retractor. The PINPOINT™ Posterior Acetabular Retractor (20071016 or 20071017) is placed posteriorly on the ischium, between the capsule and the labrum. Extending the hip at this point relaxes the posterior soft tissues and aids in retractor placement.

The PINPOINT™ Retractor (20071016 or 20071017) is temporarily fixed into position using 1/8 inch Steinmann pins, facilitating posterior rim exposure. Soft tissue is cleared from within the acetabulum, and removal of the labrum is facilitated using a long pituitary-type Ronguer (20070035). Traditional rongeurs are too large and obscure the view of the acetabular rim. The entire acetabular rim should be visible with the retractor array as described.

Complete removal of the labrum is carried out. The obturator artery is often encountered posteriorly. After removal of soft tissue, bleeding can be controlled using electrocautery (a long bovie tip is recommended). An oval skin opening is generally visible at this point and the reamers and acetabular component will be readily passed through this space. Occasionally, the calcar will drift proximally. Lifting the knee will help clear the path for the acetabular reamers.