Surgical Technique

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SBG™

Nota Bene

The following technique is for informational and educational purposes only. It is not intended to serve as medical advice. It is the responsibility of treating physicians to determine and utilize the appropriate products and techniques according to their own clinical judgment for each of their patients. For more information on the SBG including its indications for use, contraindications, and product safety information, please refer to the product’s label and the Instructions for Use packaged with the product.

Contents

Indications / Contraindications .......................................................... 4

Warning and precautions ................................................................... 5

Case Studies ...................................................................................... 6

Preoperative Planning ........................................................................ 8

Surgical Technique ............................................................................. 8

Removing the SBG™ stem .................................................................. 13

Sterilization ........................................................................................ 15

Implants ............................................................................................. 17

Instrumentation ................................................................................. 18

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• Advanced degeneration of the hip joint as a result of degenerative, post-traumatic or rheumatoid arthritis.

• Dysplasia coxarthrosis with confined medullary cavity

• Fracture or avascular necrosis of the femoral head

• Unstable femoral neck fractures

• Conditions resulting from previous operations, such as osseosynthesis, joint reconstruction, arthrodesis, hemiarthroplasty or hip total prosthesis.

• Geriatric traumatology

• Coxarthrosis

• Acute or chronic infections, local or systemic

• Local infections of the area operated

• Severe muscle, nerve or vascular diseases that endanger the extremity in question

• Lacking bone substance or inadequate bone quality that endangers a stable seating of the prosthesis

• All concomitant diseases that may endanger the function of the implant, such as:

– Any allergies to implant materials – Renal insufficiency – Cardiac insufficiency (e.g. as a result of increased metal/ions concentration in the blood)

• Pathological fractures

• Pertrochanteric to subtrochanteric fractures

• Pregnancy

Indications

Contraindications

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Warnings and precautions

The following may not be implanted under any circumstances• Implant components that have been damaged or scratched• Implants that have been handled inappropriately or

processed in a way that is not part of the surgical technique• Implants that have already been used• Implants where the packaging and/or labelling is damaged or not intact

Please return the affected devices to the appropriate Smith & Nephew representative or sales office.

Reliable fit of femoral ball heads on stem tapersThe taper connection can only be reliably and firmly seated if the surface of the ball head cone and the surface and structure of the hip stem taper are completely intact. The disposable plastic cap protecting the stem taper from damage shall not be removed until the trial ball is attached. To ensure that the ball head performs as re-quired, it is essential to take great care when attaching it to the stem taper: Clean and dry the neck taper with a clean, sterile cloth. Place the prosthetic femoral head on the neck taper and firmly impact with the femoral head impactor and a mallet several times. Never reuse a femoral ball head that has been impacted onto a stem cone and then removed.

Restrictions on head/insert combinations• BIOLOX®forte/delta ceramic inserts must only be combined with BIOLOX®forte/delta ceramic ball heads

Restrictions on head/taper combinations• Material: Stainless steel (FeCrNiMoNbN) heads and stainless steel stems should only be used together. Neither

should be used with other metal components.• Sizes: all ball head sizes of Smith&Nephew Orthopaedics AG can safely be used with all hip stems of

Smith&Nephew Orthopaedics AG. For combinations with components of other manufactures (e.g. Smith & Nephew Inc.), the surgeon must verify if the combination is allowed as listed in the compatibility matrix (lit. no. 04758) available on www.smith-nephew.com/compatibilitymatrix. Ball heads should only be combined with hip stems of identical taper dimensions.

Femoral ball head revisionsFor the revision of a femoral ball head, apply the following:• The corresponding insert has to be revised as well.• Replacement only by a metal ball head or a special ceramic revision femoral ball head featuring a metallic taper

adaptor (BIOLOX® OPTION). Do not assemble a standard ceramic head on a used taper; the ceramic head may fracture from irregularities on the femoral component taper.

• In the case of a revision involving a fractured ceramic component, femoral ball head and insert have to be revised. Remove all loose identifiable fragments and thoroughly irrigate and lavage the operative site. A special ceramic revision femoral ball head coupled with a metallic taper adaptor should be used if the femoral taper is intact. Metal or Oxinium femoral ball heads with a polyethylene insert shall not be used for revising fractured ceramic components. In case the taper is damaged or no appropriate ceramic revision femoral ball head is available, the femoral stem must be revised to provide a suitable femoral taper to attach a new ceramic ball head.

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Case Study

48-year-old patient with femoral headnecrosis, right hip.

Management with a total hip endoprosthesis, anSBG™ stem, in November 1991.

After 10 years in situ the X-ray image does not showany lytic zones in the calcar region.

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50-year-old patient with coxarthrosis, right hip. Management with a total hip endoprosthesis, anSBG™ stem in February 2007.

After 16 months in situ the X-ray image does notshow any lytic zones in the calcar region.

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Preoperative Planning

For surgical planning there are radiographic templates available on a scale of 1.15:1. Theappropriate template is used to define stem size, implant depth, resection line and leg length.

Surgical TechniqueThe following illustrations show exemplarily the surgical technique for the minimal invasive anterolateral approach.

Incision

Laterally above the greater trochanter. Divide the fascia lata longitudinally, directly dorsal of the tensor fasciae latae muscle. Lift the fascia lata and the tensor fasciae latae muscle. Without cutting enter between the vastus lateralis muscle and the gluteus medius and minimus muscles onto the ventral side of the femoral neck.

Divide the joint capsule longitudinally towards the femoral neck and make a T-shaped incision so that the femoral neck and femoral head can be exposed.

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Measuring leg length (optional)

Insert a Kirschner wire in the area of the spina iliaca anterior superior.

Attach an approx. 60 cm ruler to the Kirschner wire and read off the leg length before head resection by applying forceps above the patella. Alternatively, the length or distance can be measured from the top of the lesser trochanter before resection of the femoral head. When leg length or distance has been measured, resect the femoral head at the typical position.

Preparation of the acetabulum

Determine the anatomical entrance plane of the acetabulum. Implant the cup, selected to suit preference.

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Preparation of the medullary cavity

Expose the cut surface of the femoral neck by rotating the leg externally through 90°, performing adduction and flexion simultaneously. Starting from the cut surface, remove cancellous bone from the medullary cavity using a curette or optionally a box chisel and then the rasps.

Using the first rasp, ensure that the femur is rasped laterally up to the cortical bone.

Gradually rasp the femur until the size defi-ned in the preoperative planning stage is reached, starting with the smallest trial rasp and increasing in size up to the selected size. This can be detected by a change in the sound of rasping as soon as the rasp is advanced as far as the cortical bone in the distal region. In order to avoid intramedullary pressure peaks always start with the smallest rasp.

Either a rasp adapter with knock plate or a rasp adapter with coupling for the rasping machine can be used.

Note

The end surface of the rasp should largely coincide with the resection surface or should protrude slightly. The rasp does not have to fill out the proximal medullary cavity completely or have proximal contact with cortical bone.

Care should be taken that the offset adapter is aligned parallel to the longitudinal axis of the femur. Otherwise a varus preparation of the medullary cavity can occur. The “rear” lateral rasp plane should be a straight extension of the medullary cavity.

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Remove the offset adapter and manually fit the neck module onto the trial rasp. There is a neck module available for trial rasp sizes 05–01, 0–3 and 4–7. Note It is important to ensure that the neck module is flat on the trial rasp and that it engages properly.

The selected trial head can either be fitted to the neck module in advance or in situ. The joint is reduced and its stability is tested, a range of motion test is carried out and the leg length is checked.

Implanting the stem

During impaction the protective cap remains on the cone. Slide the implant into the prepared bone bed by hand.

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The stem impactor is inserted into the defined impaction hole on the prosthesis. The stem is driven home with carefully administered blows on the impactor. In order to achieve optimum results consider the anatomical conditions and the setting with regard to varus/ valgus position and antetorsion of the stem. The oval design of the stem impactor and the impactor hole allows the torsion to be well controlled by turning the impactor. As a result of its anatomical shape the prosthesis seeks the optimum path and “pressfit” on its own. The end of the coating of the prosthesis does not have to be at the same level as the resection level. It may project beyond the resection surface.

Note

As with rasping, here too the sound of the hammer blows is indicative of contact with cortical bone. As soon as the definitive position has been reached and the sound becomes higher-pitched do not knock the implant in any further or else there will be a higher risk of the femur fracturing. If in doubt, to ensure that the implant fits snugly, select the larger size rather than a size which is too small.

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Then perform reduction and determine leg length using a trial head; the leg can be lengthened or shortened as necessary (see section «Measuring leg length»). Before positioning the ball head, carefully wash the stem cone with water and then dry. Then position the ball head and secure in place with slight rotation. The ball head is firmly impacted using the plastic Head Impactor. The joint is then reduced, manipulated and retested to ensure proper functioning. That is followed by irrigation, drainage and wound closure. Note Please carefully read the chapter “Reliable fit of femoral ball heads on stem tapers” on page 7. Ceramic heads must never be impacted using a metal instrument.

The SBG stem can be removed with the extraction block and the M8 extraction screw.

Another option is the extraction instrument which is used with the M8 extraction screw. Initial position of the extraction instrument is open.

Removing the SBG™ stem

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First, the extraction screw is screwed into the thread with approximately two turns.

The two outer parts must be folded inwards; first the plastic part and then the metal part.

The two plastic parts form a bed for the 12/14 cone; the metal part covers the plastic part, clamping it tight. Place the folded instrument over the cone. The extraction screw must always face the axial direction.

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ImplantsAll the implants described in this Surgical Technique are sterile when they are delivered bythe manufacturer. Resterilization is not allowed.

InstrumentsSystem components and instruments are not sterile when they are delivered. Before use theymust be cleaned by the usual methods in accordance with internal hospital regulations and sterilized in an autoclave in accordance with the legal regulations and guidelines applicable in the relevant country. For detailed information please refer to leaflet Lit. no. 03389.

The correct settings are given in the instructions for use issued by the autoclave manufacturer. Instrument manufacturers and dealers accept no responsibility for sterilization of products by the customer.

Sterilization

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Stem right SAP No. Art. No. Size Length (L)75001076 0061141T 05 R 105 mm75001078 0061142T 03 R 114 mm75001080 0061143T 02 R 119 mm75001082 0061144T 01 R 124 mm75001084 0061145T 0 R 129 mm75001086 0061146T 1 R 135 mm75001088 0061147T 2 R 141 mm75001090 0061148T 3 R 147 mm75001092 0061149T 4 R 153 mm75001094 0061150T 5 R 159 mm75001096 0061151T 6 R 166 mm75001098 0061152T 7 R 169 mm

Stem left SAP No. Art. No. Size Length (L)75001100 0061161T 05 L 105 mm75001102 0061162T 03 L 114 mm75001104 0061163T 02 L 119 mm75001106 0061164T 01 L 124 mm75001108 0061165T 0 L 129 mm75001110 0061166T 1 L 135 mm75001112 0061167T 2 L 141 mm75001114 0061168T 3 L 147 mm75001116 0061169T 4 L 153 mm75001118 0061170T 5 L 159 mm75001120 0061171T 6 L 166 mm75001122 0061172T 7 L 169 mm

Implants

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Set. No. SAP: 75200176Set. No. Art.: 0942165

SAP No. Art. No. Description Size 75023003 21000615 Case for Rasp, right 75007661 990019 Cover Instrument Case1 75004439 21000075 MIS Detachable Rasp 05 R 75004440 21000076 MIS Detachable Rasp 03 R 75004441 21000077 MIS Detachable Rasp 02 R 75004442 21000078 MIS Detachable Rasp 01 R 75004443 21000079 MIS Detachable Rasp 0 R 75004444 21000080 MIS Detachable Rasp 1 R 75004445 21000081 MIS Detachable Rasp 2 R 75004446 21000082 MIS Detachable Rasp 3 R 75004447 21000083 MIS Detachable Rasp 4 R 75004448 21000084 MIS Detachable Rasp 5 R 75004449 21000085 MIS Detachable Rasp 6 R 75004450 21000086 MIS Detachable Rasp 7 R2 75007311 600924 MIS Double-Offset Adapter, right 17/13 mm

Instrumentation

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Set. Nr. SAP: 75200177Set. Nr. Art.: 0942166

SAP No. Art. No. Description Size 75023002 21000614 Case for Rasps, left 1 75007661 990019 Cover Instrument Case 75004451 21000087 MIS Detachable Rasp 05 L 75004452 21000088 MIS Detachable Rasp 03 L 75004453 21000089 MIS Detachable Rasp 02 L 75004454 21000090 MIS Detachable Rasp 01 L 75004455 21000091 MIS Detachable Rasp 0 L 75004456 21000092 MIS Detachable Rasp 1 L 75004457 21000093 MIS Detachable Rasp 2 L 75004458 21000094 MIS Detachable Rasp 3 L 75004459 21000095 MIS Detachable Rasp 4 L 75004460 21000096 MIS Detachable Rasp 5 L 75004461 21000097 MIS Detachable Rasp 6 L 75004462 21000098 MIS Detachable Rasp 7 L2 75007310 600923 MIS Double-Offset Adapter, left 17/13 mm

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Set. No. SAP: 75200178Set. No. Art.: 0942167

SAP No. Art. No. Description Size 75023001 21000613 Case General Instruments 75007661 990019 Cover Instrument Case1 75007254 600620 MIS Offset Box chisel 2 75007307 600920 MIS Offset Adapter 25 mm3 75001747 1060909 Bolt 4 75004680 21000356 SBG™ Modular Neck 05–01 75004681 21000357 SBG Modular Neck 0–3 75004682 21000358 SBG Modular Neck 4–75 75002160 110242 Head Impactor 6 75004685 21000361 SBG MIS Impactor 7 75004701 21000377 Pull-out Hook 8 75002320 110902 Extraction Block 9 75002325 110911 Extraction Screw M8 J 75002424 111053 Extractor K 75100843* 75100843 Trial Femoral Head 28 XS/-3 75100844 75100844 Trial Femoral Head 28 S/+0 75100845 75100845 Trial Femoral Head 28 M/+4 75100846 75100846 Trial Femoral Head 28 L/+8 75100847 75100847 Trial Femoral Head 28 XL/+12 75100848 75100848 Trial Femoral Head 28 XXL/+16 75100849* 75100849 Trial Femoral Head 32 XS/-3 75100850 75100850 Trial Femoral Head 32 S/+0 75100851 75100851 Trial Femoral Head 32 M/+4 75100852 75100852 Trial Femoral Head 32 L/+8 75100853 75100853 Trial Femoral Head 32 XL/+12 75100854 75100854 Trial Femoral Head 32 XXL/+16 75100855* 75100855 Trial Femoral Head 36 XS/-3 75100856 75100856 Trial Femoral Head 36 S/+0 75100857 75100857 Trial Femoral Head 36 M/+4 75100858 75100858 Trial Femoral Head 36 L/+8 75100859 75100859 Trial Femoral Head 36 XL/+12L 75004468* 21000107 MIS Offset Adapter with Plate 25 mmM 75000642* 21000378 Knock Plate* special size (optional)

Optional: SAP No. Art. No. Description Size 75210288       75210288       SET 22 mm Trial Femoral Heads     S/+0 to XL/+12 75210292 75210292       SET 40 mm Trial Femoral Heads     XS/-4 to L/+8 75210293 75210293       SET 44 mm Trial Femoral Heads     XS/-4 to L/+8 75004665 21000341 Hollow Chisel 75004666 21000342 Rod for Box Chisel

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Optional Rasp Adapters:

Set No. SAP No. Item No. Description Size1 75200169 75007309 600922 Offset-Adapter 10mm2 75200166 75007307 600920 Offset-Adapter 25mm3 75200168 75007308 600921 Offset-Adapter 40mm 75007310 600923 Offset-Adapter left 17/13mm 75007311 600924 Offset-Adapter right 17/13mm 75004612 21000262 Offset-Adapter left 60/25mm 75004613 21000263 Offset-Adapter right 60/25mm6 75210372 75004614 21000264 Offset Adapter w. Plate 45°7 75210406 75004468 21000107 Offset Adapter w. Plate 25mm

752001714

75210202

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Notes

Notes

Notes

ManufacturerSmith & Nephew Orthopaedics AGOberneuhofstrasse 10d6340 BaarSwitzerland

www.smith-nephew.com

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