cemented hip stem - smith & nephew · pdf filecemented hip stem ™ nota bene: the

C E M E N T E D H I P S T E M

Nota Bene: The technique descrip-
tion herein is made available to the
healthcare professional to illustrate
the authors suggested treatment
for the uncomplicated procedure.
In the final analysis, the preferred
treatment is that which addresses the
needs of the patient.
SURGICAL TECHNIQUECOMPLETED IN CONJUNCTION WITH
Paul Pellicci, M.D.New York, New York
Robert B. Bourne, M.D., F.R.C.S.(C)London, Ontario, Canada
Peter Brooks, M.D.Cleveland, Ohio
Wayne M. Goldstein, M.D.Chicago, Illinois
James Guyton, M.D.Memphis, Tennessee
Jim Kudrna, M.D.Chicago, Illinois
David LaVelle, M.D.Memphis, Tennessee
Cecil H. Rorabeck, M.D.London, Ontario, Canada
James Harkess, M.D.Memphis, Tennessee

4
PREOPERATIVE PLANNINGBoth an anteroposterior radiograph of the pelvis with the hips in neutral rotation and a lateral hip radiograph optimize preoperative templating. The proximal one-third of the femur should be visible on these radiographs.
Reference points should be placed at the center ofthe femoral head and the junction of the femoralneck and proximal border of the lesser trochanter onthe anteroposterior radiograph. This should be doneon both the operative and nonoperative sides. Thedistance between the center of the femoral head andthe point at the top of the lesser trochanter shouldbe measured with the ruler on the X-ray template.
This should be done on both the operative and non-operative sides as shown in Figure 1. If there is asignificant discrepancy, a straight line can bedrawn across the inferior margins of the obturatorforamina to determine where the line intersects
both femora. The surgeon can then determinewhether lengthening of the operative side is needed.
NOTE: Evidence of a leg length discrepancy should becorroborated by a preoperative physical examination.
The appropriate size stem should be chosen basedupon the size of the femoral canal and the desiredcement mantle. The cement mantle outlined on the X-ray template should reach the endostealsurface over the mid-portion of the stem as shown in Figure 2. A through-the-groin lateral X-ray can be used to more accurately determineproper stem sizing.
Figure 1. Anteroposterior radiograph demonstrating one method of determining leg length inequality.
Figure 2. Anteroposterior radiograph demonstratingproper templating of a femur.
PREOPERATIVE PLANNING
120% MAGNIFICATION
Neck LengthStandard Offset: 32 mmHigh Offset: 37 mm
Synergy is a trademark of Smith & Nephew, Inc.
MM0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
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190
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S Y N E R G Y C E M E N T E D S T A N D A R D A N D H I G H O F F S E T S I Z E 1 3
03/99 7138-0444
1999 Smith & Nephew, Inc., Memphis, TN U.S.A.
SIZE13
For use with Smith & Nephew12/14 femoral heads only.
-3 and +16 femoral headsavailable in 28 mm and 32 mm only.
*Denotes skirted heads
13
43 mm
37 mm
30 mm
130 mm
+16+12
+8+4+03
**
CementMantle
RecommendedCentralizer 10 mm
10
20
30

5
On the anteroposterior film, the center of rotation of the prosthetic femoral head should overlay thecenter of rotation of the patients femoral head. In cases of significant distortion on the operativeside, the non-operative side may be used. With the stem centered in the canal and the prostheticcenter of rotation aligned with the patients center of rotation, the neck cut can be marked through the slot in the template. The distance between thismark for the neck cut and the mark on the lessertrochanter should be recorded. This number will aid in making the femoral neck resection at theappropriate level.
With the X-ray template in proper alignment, thefemoral head neck length and stem offset should be recorded. Using this methodology helps to optimize both the leg length and offset of the proximal femur.
A properly implanted Synergy cemented stem thatprovides both normal leg length and offset is shownin Figure 3.
Figure 3. Anteroposterior radiograph of a properlyimplanted Synergy cemented stem.
PREOPERATIVE PLANNING

RecommendedStem Centralizer Cross A-P M-L
Size Length Size Section Width Width9 110 mm 8 mm 8 mm 11 mm 24 mm
10 115 mm 8 mm 8 mm 12 mm 25 mm
11 120 mm 9 mm 9 mm 13 mm 26 mm
12 125 mm 10 mm 10 mm 14 mm 27 mm
13 130 mm 10 mm 11 mm 15 mm 28 mm
14 135 mm 11 mm 12 mm 16 mm 29 mm
15 140 mm 12 mm 13 mm 17 mm 30 mm
16 140 mm 12 mm 14 mm 18 mm 31 mm
17 140 mm 13 mm 15 mm 19 mm 32 mm
6
When Femoral Head Component Selected Is:
Size 3 +0 +4 +8 +12 +169 28 31 35 39 43 47
9 HO 32 35 39 43 47 51
10 29 32 36 40 44 48
10 HO 33 36 40 44 48 52
11 29 32 36 40 44 48
11 HO 33 36 40 44 48 52
12 30 33 37 41 45 49
12 HO 34 37 41 45 49 53
13 31 34 38 42 46 50
13 HO 35 38 42 46 50 54
14 32 34 38 42 46 50
14 HO 37 40 44 48 52 56
15 32 35 39 43 47 51
15 HO 37 40 44 48 52 56
16 33 36 40 44 48 52
16 HO 38 41 45 49 53 57
17 34 37 41 45 49 53
17 HO 39 42 46 50 54 58
NECK LENGTH MM
Size 3 +0 +4 +8 +12 +16
9 25 27 29 32 35 37
10 26 27 30 33 35 38
11 26 28 31 33 36 39
12 27 29 31 34 37 39
13 28 30 32 35 38 40
14 28 30 33 35 38 41
15 29 30 33 36 38 41
16 29 31 34 37 39 42
17 30 32 35 38 40 43
For use with Smith & Nephew 12/14 taper femoral heads only.
Size 3 +0 +4 +8 +12 +169 32 34 37 40 43 46
9 HO 38 40 43 46 49 52
10 33 35 38 41 44 47
10 HO 39 41 44 47 50 53
11 34 36 39 42 45 48
11 HO 40 42 45 48 51 54
12 34 37 40 43 46 49
12 HO 40 43 46 49 52 55
13 35 37 40 43 46 49
13 HO 41 43 46 49 52 55
14 36 38 41 44 47 50
14 HO 44 46 49 52 55 58
15 37 39 42 45 48 51
15 HO 45 47 50 53 56 59
16 37 40 43 46 49 52
16 HO 45 48 51 54 57 60
17 38 40 43 46 49 52
17 HO 46 48 51 54 57 60
NECK OFFSET MM
NECK HEIGHT MM
NECK LENGTH MM
SPECIFICATIONS
STEM SPECIFICATIONS

7
NOT ACTUAL SIZE
NOTE: For illustration purposesonly. Surgical templates areavailable by contacting yourSmith & Nephew Representativeor Customer Service.
3 and +16 femoralheads available in 28 mmand 32 mm only.
*Denotes skirted heads.
Neck LengthStandard OffsetHigh Offset
HIGH OFFSET
+16+12
+8+4+03
**
STANDARD OFFSET
STEM LENGTH
CEMENTMANTLE(1 mm)
NECK HEIGHT
A-P WIDTH
M-L WIDTH
NECK L
ENGTH
CROSSSECTION
DISTALCENTRALIZER
2-3 mmCEMENTMANTLE
NECK ANGLE131
10
20
30
00

8
2.PrepareAcetabulumIf acetabular reconstruction isrequired, prepare the acetabulumusing the surgical technique for the intended acetabular component.
1.FemoralOsteotomyThe point of the femoral neck resectionshould be marked with electrocauterycorresponding to both the preoperativetemplating and the intraoperative measure-ment. Prior to the resection of the femoralhead, assemble the broach, trial neck andtrial femoral head corresponding to theimplant that was templated. Place this trial stem on the femur to verify that the center of the prosthetic head alignswith the center of the femoral head. This will confirm that the level of thefemoral neck resection is appropriate and will reestablish the desired leg length and offset of the proximal femur. Osteotomize the femoral neck (Figures 1A and 1B.)
Figure 1A
Figure 1B
SURGICAL TECHNIQUE

9
3.Femoral CanalPreparationRemove remnants of thefemoral neck and open themedullary canal using thebox osteotome (Figure 2).Use the canal finder andmodular T-handle forinitial femoral reaming(Figure 3).
NOTE: It is important to stay lateral with both the box osteotome and canalfinder. Care should be taken to ensure that theinitial reaming tract into the femur is in neutralalignment with the femoral axis.
Figure 2
Figure 3
SURGICAL TECHNIQUE

10
4.Opening Of TheFemoral CanalContinue to enlarge thefemoral canal sequentially using the femoral reamers.Each reamer is marked with two or three lines. Stopreaming when the mark onthe reamer associated withthe templated stem size iseven with the medial femoralneck resection or endostealbone resistance is encoun-tered (Figure 4). If reamingbecomes difficult beforereaching the templated stemsize, consider using a stemsize smaller than thetemplated stem size.
NOTE: It is important to staylateral with the femoral ream-ers to ensure that the canal isbeing opened in neutral align-ment with the femoral axis.
Figure 4
SURGICAL TECHNIQUE

11
5.Broach Assembly/DisassemblyAssemble the broach to the broachhandle by placing the broach post in the clamp. Use thumb to lock the clamp onto the broach. Amodular anteversion handle can be assembled to the broachhandle to provide version control(Figure 5A).
Disassemble the broach from thebroach handle by placing two fingers(index and middle) in the rectangu-lar slot. Apply pressure to the releasebar by squeezing the two fingerstoward the thumb resting on themedial side of the broach hand

cemented hip stem - smith & nephew · pdf filecemented hip stem ™ nota bene: the

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