OMNI ARC HIP SYSTEM SURGICAL TECHNIQUE ... Caution: Do not excessively impact the stem. Excessively...

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Transcript of OMNI ARC HIP SYSTEM SURGICAL TECHNIQUE ... Caution: Do not excessively impact the stem. Excessively...


  • Table of Contents

    Indications & Contraindications

    Technique at a Glance

    Femoral Canal Preparation

    Implant Trialing

    Implant Insertion

    Implant Removal

    Implant Sizing

    Instrument List


    Note: Please refer to the Product Insert (Instructions for Use) for important information pertaining to the product description and handling, indications for use, warnings and precautions, possible adverse effects, and contraindications.










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  • Indications for Use: The OMNI ARC™ Hip Stem is intended for use as the femoral component of a primary or revision total hip replacement when used with the OMNI Interface™ Acetabular System. The OMNI Interface Acetabular System articulates with the OMNI Modular Femoral Head (Cobalt Chromium or Ceramic). The femoral hip stem is intended for uncemented fixation and single use implantation. These prostheses may be used for hip arthroplasty to treat the following conditions, as appropriate:

    • Non-inflammatory degenerative joint disease, including osteoarthritis and avascular necrosis; • Rheumatoid arthritis; • Correction of functional deformity; • Congenital dislocation; • Revision procedures where other treatments or devices have failed; • Femoral neck and trochanteric fractures of the proximal femur.

    The ARC Hip Stem is also intended for use in hemiarthroplasty when used with the OMNI Bipolar Head. For further details, please refer to the OMNI Bipolar Head Instructions for Use.

    Contraindications Absolute contraindications include: • Infection or sepsis or osteomyelitis; • Insufficient bone structure or quality that may affect the stability of the implant; • Rapid joint destruction or bone absorption; • Skeletal immaturity; • Muscular, ligamentous, neurological, vascular deficiencies or poor skin coverage that may

    compromise the affected extremity; • Alcoholism or other addictions; • Sensitivity to the implant materials; • High levels of physical activity (e.g. competitive sports, heavy physical labor); • Obesity that can produce loads on the prosthesis that can lead to failure of the fixation of the

    device or the device itself; • Use of a head offset greater than +7mm. Relative contraindications include: • Uncooperative patient or a patient with neurological disorders and incapable of following

    instruction; • Metabolic disorders that may impair bone formation or bone quality; • Distant foci of infections.


    2 | O M N I A R C H I P S YS T E M S U R G I C A L T EC H N I Q U E









    Resect Femoral Neck Open Femoral Canal Rasp Femoral Canal

    Trial Neck Options Trial Head Options Implant Final Stem

    Implant Femoral Head Implant Removal

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  • Femoral Neck Resection The neck resection for the ARC stem is typically conservative. The recommended location of the osteotomy is in Zone B as described in Figure 1. This will provide the most options for restoring the proper leg length and offset.

    Zone A : 0-5mm Sub Capital

    Zone B : 5-10mm Sub Capital

    Zone C : >10mm Sub Capital

    Fine tuning the cut may be necessary after an initial assessment during trialing. It is important to make the initial cut conservative to preserve the option of resecting additional bone if needed.

    Make the cut perpendicular to the neck axis to ensure uniform engagement between the bone and the proximal stem. The Neck Resection Guide is included in the instrument set for additional reference. (Fig. 2)





    4 | O M N I A R C H I P S YS T E M S U R G I C A L T EC H N I Q U E

    Figure 2

    Figure 1

  • Opening Femoral Canal Open the femoral canal using the Starter Awl. Note the direction of the tip of the Starter Awl relative to the handle. (Fig. 3) Apply light pressure on the handle laterally (towards the greater trochanter) as the Awl is advanced to help guide the tip on a curved path along the calcar.

    Using the Canal Finder, expand the opening created by the Awl to prepare for rasping. Continue to follow the medial curve, working the handle back and forth to expand the canal opening. (Fig. 4)

    Proximal Canal Preparation Utilize the Starter Rasp to begin preparing the proximal femur. Like the Starter Awl, apply light pressure on the handle laterally (towards the greater trochanter) as the Starter Rasp is advanced to help guide the tip on a curved path along the calcar. The Starter Rasp is fully seated when the transition of the teeth and handle is flush with the neck cut. (Fig. 5).


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    Figure 3

    Figure 5

    Figure 4

  • Initial Trialing with the Rasp Once the final Rasp has been seated, begin by attaching the Neutral Neck Trial (Fig 6). Attach the appropriate Head Trial to the Neutral Neck Trial and reduce the hip joint (Fig 7).

    Conduct a thorough range of motion anlysis to check for bony impingement.

    Assess the stability and leg length. If necessary, change the neck trial and/or head trial and repeat trial reduction until the desired result is achieved.

    Refer to the “Head Center Position” table (page 10) of this technique to see how different neck and head combinations affect leg length and offset.

    Reduce the hip and assess the joint mechanics. If the hip is too tight, it may be appropriate to resect a little more bone from the femoral neck. If the hip is loose, an increased head trial should be used when performing trial reduction with the final Stem.

    After completing the initial trial reduction, remove the Rasp.


    Trial Color Black/Brown

    Gray Dark Blue

    Head Trial -3.5 mm

    +0 +3.5 mm

    Green +7 mm

    6 | O M N I A R C H I P S YS T E M S U R G I C A L T EC H N I Q U E

    Figure 6

    Figure 7

  • Stem Insertion Insert the selected ARC Stem into the femoral canal and push the implant into position as far as possible with hand pressure. Use the Monoblock Stem Inserter by placing the round tip of the impactor into the lateral stem impactor indent on the stem. (Fig 8)

    Impact the Stem until the prosthesis is level with the neck resection. The edge of the proximal coating should be flush with the neck resection. However, depending on bone quality and femoral preparation technique, the stem may sit a couple of millimeters proud of the resected surface. This can also be affected by how planer the neck resection was prepared.

    Caution: Do not excessively impact the stem. Excessively impacting the stem may result in bone fracture. If stem does not seat with normal impaction, consider re-inserting the Rasp to clear away additional bone.

    Femoral Head Impaction The selected femoral head implant is then inserted over the neck trunnion and impacted using the supplied femoral head impactor. (Fig 9)

    NOTE: All taper surfaces should be thoroughly cleaned and dried prior to inserting the neck into the stem.


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    Figure 8

    Figure 9

  • Attach the Monoblock Stem Extractor Adaptor to the end of the Slap Hammer. Slide the U-shaped stem extractor slot onto the implant neck below the neck trunnion and turn the locking thread until tight. (Fig. 10)

    Apply quick, short strikes with the Slap Hammer Weight to remove the Stem from the femur. Frequently check the connection of the Slap Hammer to the Neck Removal Adaptor to the neck and re-tighten, if necessary.


    8 | O M N I A R C H I P S YS T E M S U R G I C A L T EC H N I Q U E

    Figure 10


    Product Code

    Size A B C*

    HC-21000 0 80 mm 90 mm 100 mm

    HC-21001 1 80 mm 90 mm 100 mm

    HC-21002 2 90 mm 100 mm 115 mm

    HC-21003 3 100 mm 111 mm 126 mm

    HC-21004 4 110 mm 121 mm 137 mm

    HC-21005 5 120 mm 132 mm 147 mm

    If the trial reduction is too tight, even when using a -3.5 mm offset Head Trial, additional bone should be resected from the femoral neck. If the trial reduction is too loose, even when using a +7 mm offset Head Trial, it may be necessary to convert to an OMNI K1™ or K2™ stem. The table below shows the smallest K Series stem corresponding to the final ARC Rasp or Femoral Implant that was used.

    ARC Rasp or Stem Size OMNI K1-K2 Stem Size

    0 2

    1 3

    2 4

    3 6

    4 7

    5 10


    B C

    OMNI ARC™ Sizing Chart

    *Measured to neutral head/neck configuration. For other head/neck options, see OMNI ARC Head Centers for relative leg length.

    9 | O M N I A R C H I P S YS T E M S U R G I C A L T EC H N I Q U E


    NE CK

    LE NG



    OMNI ARC™ Head Centers Offset and leg length measurements are relative to a neutral neck, neutral head combinati