Avanteon®Primary total hip replacement OPERATIVE TECHNIQUE

Femoral Head Resection 3 Femoral Canal Preparation 8 Cement Plug Insertion 11 Femoral Stem Implantation 12

Pre-Operative Planning The overall aim of pre-operative planning is to establish anatomical data from the patient to guide the surgeon towards the optimal size of the femoral stem and acetabular component and their ideal position after implantation. Anteroposterior and lateral X-rays with the hip in neutral position are overlaid with the template film for full pre-operative evaluation. ARCHIVING SYSTEMS templates are also available via your PACS software provider. The X-ray templates for the AVANTEON® Hip system are set at 115% magnification. An example of templating for the AVANTEON® hip system...

Femoral Head Resection Resection cutouts Head centres Stem sizes Central axis of the stem The centre of rotation of the femoral head can also be established, which will help determine appropriate offset and neck length to achieve correct soft tissue tension. The appropriate level to make the femoral neck osteotomy can be identified using the osteotomy guide (007027), and this should be used in conjunction with reference to the pre-operative templating. The AVANTEON® osteotomy guide is placed over the exposed proximal femur and positioned so that the alignment guideline on the device aligns with...

Acetabular Preparation The acetabular rim is fully exposed, identifying and osteophytes. Starting with the smallest reamer, the articular cartilage is progressively reamed until bleeding subchondral bone becomes visible (Figure 3). It is important not to over-ream the anterior and posterior walls. In order to achieve a 3mm thick cement mantle, the final implant is downsized by 6mm from the final reamer size used. Several holes are then made around the acetabulum using the acetabular step drill (007042). These holes are created to aid keying and fixation of the bone cement (Figure 4). Care should...

manufactured from UHMWPE. The rings on the flange are set 2mm apart (Figure 5). Present the cup to the prepared acetabulum to assess the amount of flange to remove, and trim the flange away from the acetabulum to avoid contamination, so that the periphery of the flange sits just inside the acetabular rim. The bone cement is mixed as per the Figure 5 manufacturer’s instructions and guidelines. Pulsed lavage and drying of the bone bed are recommended prior to cementation. Bone cement is introduced into the acetabulum in the normal manner. An acetabular pressuriser should be used to intrude the...

The acetabular cup is introduced so the shaft of the inserter is at 90° to the sagittal plane of the body. The cup is then positioned at 45° of abduction (Figure 8). The acetabular cup pusher (007047) engages with the acetabular cup inserter, and pressure is applied to the cup directly in line with the cup face or 45° to the vertical of the acetabular inserter handle. The anteversion handle (007052) can be used to confirm the degree of anteversion relative to the coronal plane of the body (Figure 9). The degree of anteversion is at the discretion of the surgeon. The pressure applied to the acetabular...

acetabular cup with the acetabular cup pusher, which attaches onto the acetabular cup inserter (Figure 10). the cup in the acetabulum and confirmation of correct alignment, the ejected from the cup by depressing the button on the end of the inserter. Once the inserter has been ejected, the acetabular cup pusher must be immediately into the cup to maintain pressure on the cement (Figure 11). Any extruded Figure 11 bone cement is removed from the periphery of the cup, and pressure is maintained until the bone cement is adequately polymerised. After polymerisation is complete, the acetabular cup...

Femoral Canal Preparation Note: Pre-operative planning and templating, by either PACS or hard-copy x-rays is essential when using a tapered, polished femoral stem to ensure correct leg length, soft tissue tension, and restoration of anatomy. Variations in patient anatomy mean that using the same anatomical reference points in the same way in every patient is inappropriate. Attach the box osteotome (small 007033, large 007034) to the broach handle (007035) and open up the medullary canal by aligning the cut of the osteotome with the piriformis. The appropriate degree of anteversion should be determined...

The AVANTEON® broaching system is designed to provide a uniform continuous cement mantle of at least 2mm. The medial cement mantle increases from 2mm at the distal tip of the stem to 4mm in the calcar region (Figure 15). Pre-operative planning will enable the surgeon to identify the correct offset stem to use. The medial curve of the broach and the stem vary depending on the stem offset. It is essential to use the correct broach that corresponds to the stem offset determined in the pre-operative planning. Figure 15 The smallest broach (CDH 36mm offset, 007100) is used first to prepare the broaches...

Trial Reduction Note: The CDH and 38mm offset stems use the same trial neck The two small holes and the ‘flat’ on the rasp where the trial neck sits correspond to the three depth markings on the definitive stem (Figure 17). The rasp can be inserted to the desired depth as indicated pre-operatively, taking note of the depth marking when rasping. The correct offset trial neck is attached to the spigot on the rasp. The trial neck must be seated properly on the rasp to ensure that the appropriate trial neck has been selected. The trial head with the neck length required to re-establish the femoral...

Cement Plug Insertion 10mm to 20mm cement gap Typical distal cement plug Figure 18 The JRI Femoral Cement Plugs can be used in conjunction with the AVANTEON® cemented hip system. • The Femoral Cement Plugs are available in a comprehensive range of sizes from 10mm to 20mm maximum diameter in 1mm increments. • Made from UHMWPE, when sized and fitted correctly the plugs provide a secure barrier against the ingress of bone cement distally down the femoral canal, enabling pressurisation. The size of cement plug to be used should be determined by using the intramedullary trials to estimate the diameter...