PATH® Technique General Precautions

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

Portal Placement
A small Acetabular Trial Shell (20070146 or 20070152) or face plate is selected and attached to the Acetabular Alignment Handle (2007S001 for CONSERVE®, 20070014 for LINEAGE®) via the Threaded Cup Adaptor (20070013), along with the Portal Placement Guide (20070015). The trial shell, usually one or two sizes smaller than that templated, is lowered into the open acetabulum. The body of the alignment handle will indicate the desired final cup position, and help position the portal placement guide. With the alignment handle shaft perpendicular to the table, the abduction angle is approximately 40°-45°. Additional adduction is sometimes required as the pelvis may be tilting 10°-15° anteriorly with the leg drawn forward and the femur retracted (alignment handle no longer perpendicular to the table). With the crossbar portion of the handle perpendicular to the patient’s torso, anteversion is approximately 20°.

The Trocar (20070016) is first placed through the Cannula (2007ST20) and then through the portal placement guide sleeve in order to create the portal just behind the posterior edge of the femur. An approximate 1 to 1.5 cm stab wound is made at the location where the trocar will intersect the leg. The trocar and cannula are passed through the stab wound, with the cannula remaining behind after the alignment handle/portal placement guide assembly is removed.

Acetabular Reaming
The Hex Socket Reamer Baskets (20071040 – 20071064) are passed through the main incision while the Reamer Shaft (20070011) is passed through the cannula. The Acetabular Reamer Adaptor (20070010 or 20070110) is available in cases where the corresponding hex socket reamer baskets are unavailable. Reaming starts one or two sizes under the templated acetabular size. Initial reaming is often carried out directly medially to remove any remaining articular cartilage. If a large central osteophyte is present, additional central reaming may be required. Reaming continues in the standard fashion until an adequate bed of bleeding bone is present.

Acetabular component size is chosen using the last reamer basket size as the cup size. In the presence of very sclerotic bone, an additional 1 mm of reaming over the nominal size may be required. Conversely, in the presence of very soft bone, under-reaming by 1mm will work best. The acetabular component is placed on the alignment handle via the BFH® Suction Plate (20072036 – 20072056) with standard hospital vacuum pressure for CONSERVE® cups or the threaded cup adaptor for LINEAGE® cups, passed through the main incision, and located in its appropriate position within the acetabulum.

Cup Impaction
The Impactor Shaft (20070017) is passed through the cannula and into the spherical tip of the Alignment Handle (2007S001 for BFH or 20070014 for Lineage). Precise component placement is carried out using the alignment guide as both a cup holder and alignment indicator. The acetabular component is impacted to the point of stability in approximately 40° of abduction and 20°-25° of anteversion using the alignment guide, bony landmarks, and an understanding of the true patient position at the time of cup placement. An intra-op radiograph is useful to precisely assess position as well as leg length during final trial reduction.

In CONSERVE® hip cases, suction is then released and the alignment guide and suction plate are removed. In LINEAGE® hip cases, after the acetabular component has been cleaned and dried, the desired liner can be impacted with the appropriate Ceramic/Metal Liner Impactor (20070023, 20070024 or 20070025) in place. Impaction proceeds in the standard manner through the cannula.

**Special attention must be taken into consideration to the patient positioning and bony anatomy for proper cup alignment. In addition, a ball spike or tamp may be used to tap the rim of the cup for minor adjustments to the final cup placement.
***If using the LINEAGE® cup implants, please note that the liner impactors are not radiolucent and must be given special attention for removal after impaction of the liner.

Femoral Preparation
Attention is then directed to the proximal femur. Soft tissue is cleared from the lateral neck and the intertrochanteric wall. The remaining lateral neck is removed using the ronguer. A Cylindrical Chisel (8000010 and 20070052, 20070053 or 20070054) can be utilized to remove the hard bone of the lateral calcar and to shave the inner wall of the greater trochanter. The Offset Hohman (20070032 or 20070033) is placed over the tip of the greater trochanter and the anterior acetabulum retractor is placed over the medial calcar and under the remaining short external rotators. The position of the hip can be 45°-80° of flexion and 45°-80° of internal rotation depending on the tightness of the soft tissues. It is always held in maximum adduction to protect the posterior skin.

Femoral Reaming / Broaching
Femoral Reamers with T-Handle (K0001016 and 4700R090, 4700R105, 4700R120 and 4700R150) assist in identifying the normal axis and in lateralizing the access channel, i.e. the opening in the upper lateral femur. Sequentially larger reamers are used to open the lateral calcar area. The Tissue Protecting Reamer Sleeve (PRFS0451) is utilized to protect the soft tissues. Broaching begins, typically with the smallest size broach, to contour and orient the femoral opening. Broaching continues until the appropriate size and insertion depth, as determined from preoperative templating, are achieved. The insertion depth should correspond to within approximately 5 mm of the templated amount. This is the measurement from the tip of the greater trochanter to the shoulder of the prosthesis, using the desired center of rotation as determined by preoperative x-rays. This amount is typically between 10 and 20 mm. The MIS Broach Alignment Bracket and Guide Rod (20070055, 20070056) can be used to ensure proper alignment during broaching. The Slotted Broach Impactor Handle (SLBROHAN or LGBROHAN) and broach alignment guide rod provide depth markings to indicate the insertion depth. Increased offset will require deeper insertion of the prosthesis and thus deeper broaching. The femoral trial is then impacted. The trial represents the true size and depth of insertion of the final implant, facilitating the most accurate trial reduction.

Stem Impaction
The neck and head trials are chosen, and final reduction is carried out. The hip should be stable in full extension and 70°-80° external rotation with pressure applied to the posterior aspect of the greater trochanter. It should also be stable between 30° and 90° flexion, 30°-50° adduction, 70°-80° internal rotation, as well as 120° flexion in neutral rotation and neutral adduction. Once the desired neck/head combination has been chosen, the trial components are removed. The actual stem is implanted, and the insertion depth is rechecked and the appropriate neck/head combination is once again trialed.

Leg length is assessed using the surgeon’s desired technique. The neck and head implants are then assembled, placed (retrograde under skin) and then into the stem pocket, and impacted. Observation should be made of the calcar integrity upon final implantation of the femoral component, and after impaction of the modular neck and femoral head. The hip is then reduced.

The final leg length and hip stability check is carried out. Adjustments are made as indicated. Occasionally, if anterior impingement is noted, additional anterior capsule is resected. Also, observation should be made for bony impingement from residual femoral neck or anterior acetabular rim osteophytes.