Versys® Fiber Metal Taper Hip Prosthesis Surgical Technique 1

VerSys® Fiber Metal Taper Hip Prosthesis Surgical Technique VerSys® Fiber Metal Taper Hip Prosthesis Surgical Technique 1 VerSys Fiber Metal Table of Contents Taper Hip Prosthesis Surgical Technique Preoperative Planning 2 Determination of Leg Length 2 Determination of Abductor Muscle Tension and Femoral Offset 3 Component Size Selection/ Templating 3 Surgical Technique 5 Incision 5 Exposure of the Hip Joint 5 Determination of Leg Length 5 Osteotomy of the Femoral Neck 5 Preparation of the Femur 7 Intramedullary Reaming (Optional) 8 Attachment of the Rasp Alignment Tip (Optional) 10 Femoral Rasping 10 Trial Reduction 11 Insertion of the Femoral Component 12 Attachment of the Femoral Head 12 Wound Closure 12 Postoperative Management 12 VerSys Fiber Metal Taper Specifications 13 Fiber Metal Taper — Standard Offset 13 Fiber Metal Taper — Extended Offset 13 2 VerSys® Fiber Metal Taper Hip Prosthesis Surgical Technique Preoperative Planning Determination of Leg Length Determining the preoperative leg Effective preoperative planning length is essential for restoration of allows the surgeon to predict the the appropriate leg length during impact of different interventions in surgery. For most patients, leg lengths order to perform the joint restoration are not equal. If leg lengths are equal in the most accurate and safest in both the recumbent and standing manner. Optimal femoral stem fit, positions, the leg length determination the level of the femoral neck cut, the is simplified. If there are concerns prosthetic neck length, and the femoral regarding other lower extremity component offset can be evaluated abnormalities, such as equinus of the through preoperative radiographic foot or significant flexion or varus/ analysis. Preoperative planning valgus deformities of the knee, perform also allows the surgeon to have the further radiographic evaluation to aid appropriate implants available at in the determination of preoperative leg surgery. length status. The objectives of preoperative planning An A/P pelvic radiograph often gives include: enough documentation of leg length inequality to proceed with surgery. 1. determination of leg length, If more information is needed, a 2. establishment of appropriate scanogram or CT evaluation of leg abductor muscle tension and length may be helpful. From the femoral offset, and clinical and radiographic information on leg lengths, determine the 3. determination of the anticipated appropriate correction, if any, to be component sizes. achieved during surgery. The overall objective of preoperative If the limb is to be significantly planning is to enable the surgeon to shortened, osteotomy and gather anatomic parameters which advancement of the greater trochanter will allow accurate intraoperative may be necessary. If the limb placement of the femoral implant. is shortened without osteotomy and advancement of the greater trochanter, the abductors will be lax postoperatively, and the risk of dislocation will be high. Also, gait will be compromised by the laxity of the abductors. If leg length is to be maintained or increased, it is usually possible to perform the operation successfully without osteotomy of the greater trochanter. However, if there is some major anatomic abnormality, osteotomy of the greater trochanter may be helpful. VerSys® Fiber Metal Taper Hip Prosthesis Surgical Technique 3 Determination of Abductor Component Size Selection/ Large patients and obese patients Muscle Tension and Femoral Templating may have magnification greater than Offset Preoperative planning for insertion 20 percent because their osseous Once the requirements for establishing of a cementless femoral component structures are farther away from the the desired postoperative leg length requires at least two views of the surface of the film. Similarly, smaller have been decided, the next step is to involved femur; an anterior/posterior patients may have magnification less consider the requirement for abductor (A/P) view of the pelvis centered at the than 20 percent. To better determine muscle tension. When the patient has pubic symphysis, and a frog leg lateral the magnification of any x-ray film, use a very large offset between the center view on an 11x17-inch cassette. Both a standardized marker at the level of of rotation of the femoral head and the views should show at least 8 inches of the femur. (Templates of 15 and 10 line that bisects the medullary canal, the proximal femur. In addition, it may percent magnification can be obtained the insertion of a femoral component be helpful to obtain an A/P view of the by special order.) with a lesser offset will, in effect, involved side with the femur internally Preoperative planning is important medialize the femoral shaft. To the rotated. This compensates for in choosing the optimal acetabular extent that this occurs, laxity in the naturally occurring femoral anteversion component, and in providing an abductors will result. and provides a more accurate estimation of the range of acetabular representation of the true medial to VerSys Fiber Metal Taper stems are components that might ultimately be lateral dimension of the metaphysis. offered in two offsets (standard and required. extended) in a 135-degree neck angle. When templating, magnification of The initial templating begins with the This versatility in offset and length the femur will vary depending on the A/P roentgenogram. Superimpose the enables the surgeon to reproduce distance from the x-ray source to the acetabular templates sequentially on almost any offset encountered. film, and the distance from the patient the pelvic x-ray with the acetabular to the film. The VerSys Hip System Although rare, it may not be possible component in approximately 40 templates (Fig. 1) use standard 20 to restore offset in patients with an degrees of abduction. Range of motion percent magnification, which is near unusually large preoperative offset or and hip stability are optimized when the average magnification on most with a severe varus deformity. In such the socket is placed in approximately clinical x-rays. cases, the tension in the abductors can 35 to 45 degrees of abduction. Assess be increased by lengthening the limb, a several sizes to estimate which method that is especially useful when acetabular component will provide the the involved hip is short. If this option best fit for maximum coverage. In most is not advisable and if the disparity is cases, select the largest component great between the preoperative offset possible, being certain that the and the offset achieved at surgery by outside diameter isn't too large to seat using the longest head-neck implant completely in the acetabulum. (Refer to possible, some surgeons may choose the various Zimmer Acetabular System to osteotomize and advance the greater surgical techniques for specific details trochanter to eliminate the slack in the on acetabular reconstruction.) abductor muscles. Technical variations in the placement of the acetabular components can also reduce the differences in offset. Fig. 1 4 VerSys® Fiber Metal Taper Hip Prosthesis Surgical Technique Consider the position and thickness The specific objectives in templating Next, check the fit of the stem on the of the acetabular component in the femoral component include: lateral x-ray. If the lateral x-ray reveals estimating the optimum femoral neck that the A/P dimension of the isthmus 1) determining the anticipated size of length to be used. (To simplify this, the is greater than the medial-lateral (M/L) the implant to be inserted, and acetabular templates are on a separate dimension shown on the A/P film, acetate sheet from the femoral 2) determining the height of the it may be advantageous to increase templates.) Mark the acetabular size implant in the femur and the the size of the stem to better fill the and position, and the center of the location of the femoral neck isthmus. Template the next larger size head on the x-rays. This allows any osteotomy. Now select the femoral component on the A/P x-ray to femoral component to be matched appropriate femoral template. determine the amount of cortical bone with the desired acetabular component The VerSys Fiber Metal Taper Hip that would be removed by reaming to by placing the femoral template over Prosthesis is available in twelve this size. The cortical thickness of the the acetabular template. This will standard body sizes (9 through walls must be great enough to allow provide the best estimation of femoral 20mm) and ten large metaphyseal for additional reaming. If a larger component size and head-neck length (LM) sizes (11 through 20mm). stem would better fill the isthmus, it necessary to achieve the correct leg is preferable to insert the larger stem. The femoral templates show the neck length. This can be accomplished by enlarging length and offset for each of the head/ the isthmus in the M/L dimension with The VerSys Hip System includes several neck combinations (-3.5 to +10.5mm, intramedullary drills. When a larger head diameters. In most patients with depending on head diameter). Note size is chosen to better fill the isthmus an average-sized acetabulum, consider that skirts are present on +10.5mm on the lateral x-ray, reevaluate the A/P a femoral head with an intermediate heads, and on the +3.5mm size 22mm x-ray to ensure that the fit of the diameter, such as 28mm or 32mm. The head. proximal and distal bodies is intermediate femoral heads allow the To estimate the femoral implant size, acceptable. use of an acetabular component with assess both the distal stem size and an outside diameter small enough to Careful attention during this process the body size on the A/P radiograph, seat completely in the bone while also helps the surgeon achieve the goal and then check the stem size on the allowing for a polyethylene liner of of implanting a stem that will provide lateral radiograph. Superimpose sufficient thickness. maximum stability and contact with the the template on the isthmus and host bone.

Load more