Surgical Technique SL-PLUS™ MIA SL-PLUS™ SLR-PLUS™ Contents Indications / contraindications .........................................................................................................2 Warnings and precautions ...............................................................................................................4 Preoperative planning ......................................................................................................................5 Surgical technique ............................................................................................................................6 Postoperative treatment ..................................................................................................................16 Explantation of the stem ..................................................................................................................17 Implants ...........................................................................................................................................18 Demo Implant ................................................................................................................................. 21 Dimensions ....................................................................................................................................22 Instruments ....................................................................................................................................28 Sterilization .....................................................................................................................................38 N.B. The surgical technique described in this brochure is the procedure suggested by the authors for uncomplicated surgery. The surgeon must, however, decide which procedure is the most suitable and effective for each individual patient. 1 Indications/contraindications Indications SL-PLUS™ MIA SL-PLUS™ SLR-PLUS™ All femur types can be treated with the exception of those with extreme curvature, e.g. after angulation osteotomies. In these cases, a corrective osteotomy beforehand may be appropriate. • Advanced degeneration of the hip joint as a result of degenerative, post-traumatic or rheumatoid arthritis • Fracture or avascular necrosis of the femoral head • Conditions resulting from previous surgery such as osteosynthesis, joint reconstruction, arthrodesis, hemiarthroplasty or hip total prosthesis The SLR-PLUS revision stem is designed for prosthetic arthroplasty in revision surgery. Indications SLR-PLUS™ • Dysplasia • Revisions of cemented and non-cemented implants due to aseptic or non-aseptic loosenings, osteolysis, dislocations or impingements • Insufficient soft tissue balancing Indications for Lateral Stem SL-PLUS™ • Varus femur forms • Trumpet shape of the proximal femur (champagne flute) • Insufficient soft tissue balancing • Status after previous operations (e.g. displacement osteotomy, pelvic osteotomy) Lateral Stem SL-PLUS™ MIA SL-PLUS™ SLR-PLUS™ The Lateral stem design has a much greater offset (see Dimensions on p. 22, 24, 26) and, at 123°, a much smaller CCD angle than the standard stem (131°). In the case of coxa vara, the CCD angle is smaller than normal (126°). Implanting a stem prosthesis with a CCD angle of 131° or more can result in a medialization and/or lengthening of the leg. By implanting a lateralizing stem, the lever arms can be reconstructed in such a way that the strength of the pelvic-trochanter muscles is restored. At the same time, an optimal soft tissue tension is achieved. This minimizes the risk of an inadequate gait and the risk of luxation, if required by the preoperative planning. 2 Contraindications SL-PLUS™ MIA SL-PLUS™ SLR-PLUS™ • 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 disease that may endanger the function of the implant, such as: - Any allergies to the implant materials - Renal insufficiency - Cardiac insufficiency (e.g. as a result of increased metal ion levels in the blood) • Revision with extensive bone defects extending for distal to the lesser trochanter and thereby reducing the stable anchoring of the stem to less than half Contraindications SLR-PLUS™ • Bone defects following tumor resections • Periprothetic fractures Important It will be seen that SLR-PLUS Revision stem may be used in a wide variety of cases. The limitation are complex revisions in which even such adjunctive measures as cerclages or wires fail to stabilize the device in the proximal part of the femur. In such cases, a long revision stem; e.g. REDAPT™ should be used, which obtains fixation in the distal half of the host bone. 3 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 tapers The 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 required, 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 revisions For 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. 4 Preoperative planning SL-PLUS™ MIA SL-PLUS™ SLR-PLUS™ Preoperative planning is essential to determine the correct orientation and size of implant. AP and axial x-rays are required for this purpose. The offset and neck length to be achieved with the prosthesis are determined with the aid of x-ray templates. X-ray Templates - scale 1.15:1 • SL-PLUS MIA stem, Lit. No. 2202 x x • SL-PLUS stem, Lit. No. 2201 • SLR-PLUS stem, Lit. No. 2203 Today, digital templating is the new standard in many institutions. Smith & Nephew is supporting a number of third party digital pre-operative planning tools. Please contact your local Smith & Nephew representative for further information. To determine the entry point in the medullary canal, the surgeon is advised to draw the femoral axis on the AP radiograph and extend this proximally. This line indicates how far laterally the box chisel needs to be placed to open up the medullary canal, thus facilitating identification of the lateral entry point at operation. It is also helpful to define the position of the stem within the canal. The distance x from the shoulder of the stem to the greater and lesser trochanter is measured and can serve as an additional leg length check. Note X-ray templating is not as reliable for determining implant sizing in revision cases as they are in planning for primary implantations and can therefore only provide an approximate estimate of the actual stem size required. 5 Surgical technique SL-PLUS™ MIA SL-PLUS™ Position of the patient and approach For the purpose of this surgical technique, the anterolateral, minimally invasive