ANATOMIC SURGICAL TECHNIQUE. 5 in 1. Conventional instrumentation 07/11/2013

Transcription

1 ANATOMIC SURGICAL TECHNIQUE 5 in 1 Conventional instrumentation PRO.GB.933/1.0 Octobre 2013

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3 Tibial step 3

4 Intramedullary technique - Based on the preoperative plan, drill the medullary canal with the 8 mm drill bit - Introduce the intramedullary rod mounted on the handle 4

5 Intramedullary technique - Assemble the column on the arm with the right or left tibial cutting guide - Place the entire assembly on the intramedullary rod - Adjust rotation before impaction of the arm spikes on the tibia - Clip the stylus onto the cutting guide (make sure clip is fully engaged) - Adjust the resection level with the stylus as follows: - on the unaffected side (10 mm cut) - on the affected side (exit level of the saw blade) - Check the bone resection level using the resection gauge - Drill 2 headless pins into the 0 holes on the tibial cutting guide 5

6 Extramedullary technique - Assemble on the arm the column with the right or left tibial cutting guide (without preliminary diaphyseal drilling) - Assemble the malleolus clamp, extramedullary tube and the column - Fix the malleolus clamp around the ankle and place the arm on the tibial plateau - Clip the stylus onto the resection guide (make sure clip is fully engaged) - Adjust the resection level with the stylus as follows: - on the unaffected side (10 mm cut) - on the affected side (exit level of the saw blade) - Check the resection level using the resection gauge - Drill 2 headless pins into the 0 holes on the tibial resection guide 6

7 Combined technique - Drill the medullary canal with the 8 mm drill bit - Introduce the intramedullary rod mounted on the handle - Assemble on the arm the column with the right or left tibial resection guide - Assemble the malleolus clamp, extramedullary tube and the column - Fix the malleolus clamp around the ankle and place the arm on the intramedullary rod - Clip the stylus onto the resection guide (make sure clip is fully engaged) - Adjust the resection level with the stylus as follows: - on the unaffected side (10 mm cut) - on the affected side (exit level of the saw blade) - Check the resection level using the resection gauge - Drill 2 headless pins into the 0 holes on the tibial resection guide 7

8 Tibial resection - Using the slap hammer, remove the intra or extramedullary assembly - Slide the resection block closer to the bone - Stabilise the resection block with the 3 headed pins - Perform the tibial resection (medium saw blade recommended thickness 1.25 mm) 8

9 Flexion and extension gaps - Check gaps using a 10 mm spacer mounted on the universal handle, which can accept extramedullary alignment rods NOTE: 2 mm and 4 mm spacers may also added to the 10 mm spacer to improve ligament tension. 9

10 Femoral step 10

11 Femoral intramedullary rod - Flex the knee to 90 - Remove peripheral osteophytes - Drill the femoral medullary canal with the 8 mm drill bit - Place the entire assembly on the intramedullary rod (length 400 mm) Note: If the rod cannot be inserted or there is a pre-existing THR, use the 250 mm intramedullary rod instead 11

12 A/P femoral measurement - Assemble posterior fork with measurement gauge - Insert the valgus barrel into the measuring gauge (angulation and right or left side) determined on x-rays in the preoperative planning or with the simulator - Check the contact with: Distal condyles Posterior Condyles - Put in place the femoral stylus on the anterior cortex 12

13 A/P femoral measurement - Lock antero-posterior space with the lateral screw using the screwdriver - Place the 7 mm spacer between the fork of the gauge (thickness: 3 mm) and the resected tibia (reproduces a 10 mm tibial resection) - 2 or 4 mm spacers may also be added to the 7 mm spacer to improve ligament tension - Check laxity 13

14 Femoral size selection - Read the size according to the graduation marks. 1st possibility: The measurement is exactly aligned with a size - In this case, the reference is both anterior and posterior - The bone resection thickness will be the same as that of the prosthesis, i.e. 8 mm on the posterior face -- Tighten the lateral screw using the screwdriver 14

15 Femoral size selection - Read the size according to the graduation marks. 2 nd possibility : Measurement is between two sizes size 3 +1 mm or size 4-2 mm For an anterior reference: the measured deviation (in millimeters) is applied to the resection of the posterior condyle In the example provided : - If smaller size selected = 9 mm posterior resection - implant thickness: 8 mm + 1 mm of bone Flexion gap will increase - If larger size selected = 6 mm posterior resection - implant thickness: 8 mm 2 mm of bone Flexion gap will decrease 15

16 Rotation selection - Rotation may be selected according to the following anatomical and/or ligament reference: - The 3 anatomical references are: - Transepicondylar axis - Posterior condylar axis - Whiteside line - Ligament landmark - The ligament reference: - An optional set of alignment simulators is available on request - Once rotation is determined, tighten the front screw using the screwdriver 16

17 Setting up threaded pins - Drill the 2 threaded pins into the barrels on the measuring gauge, using the quick release adaptor (universal or A.O.) - Remove the 2 barrels, the intramedullary rod and the measuring gauge 17

18 Femoral resection - Set up the 5-in-1 cutting guide of the selected size onto the pins STANDARD 5-IN-1 FEMORAL RESECTION BLOCK - Check contact with at least one distal condyle - Set up the cutting guide stabiliser and fix it with a headed pin (monocortical) - Fix the 5-in-1 cutting guide with 4 headed pins, always starting with the side in contact with the distal condyle - Remove the 2 threaded pins - Perform the 5 cuts - Remove the headed pins with the pin extractor, and then remove the cutting guide 18

19 Femoral resection Note: IMA 5-IN-1 FEMORAL RESECTION BLOCK - If you use the IMA 5 in 1 cutting guide, fix one or two lateral stabilizers and the femoral cutting guide stabilizer (with the H5 screewdriver) - A threaded pin in in the trochlear groove can come to replace the femoral cutting guide stabilizer - Remove one threaded pin to make 5 half-cuts, then put back in place the threaded pin & remove the second pin to finish the 5 other half-cuts 19

20 Flexion and extension gaps - Extension and flexion gaps may be checked with the 18 mm spacer (10 mm from tibial resection and 8 mm of distal resection) - 2 and 4 mm spacers may also be added to the 18 mm spacer Caution: with the last observation (remove first posterior capsule) 20

21 Final femoral preparation Oval clip used to attach universal handle - Choose the femoral preparation guide of corresponding size. Place universal handle onto oval clip by simultaneously pushing and turning handle - Place femoral preparation guide onto cuts - The guide and the implant medial-lateral dimension are similar. Use the two windows on the anterior face to help position the guide : - The outer (lateral) side of the guide corresponds to the outer edge of the replacement condyle - The inner (medial) side of the window corresponds to the inner edge of the replacement condyle 21

22 Final femoral preparation - The mediolateral position of the guide can also be determined using the line marking the center of the guide - Fix femoral preparation guide with 3 headed pins 22

23 Final femoral preparation - Insert the notch reamer until it stops Nota: Select the reamer size regarding femoral finition guide one 23

24 Final femoral preparation - Place the appropriate box chisel for the side being operated on (left or right) onto the universal handle - Prepare the trochlea using the box chisel within the preparation guide NOTA : Make sure the box chisel is properly oriented top to bottom! 24

25 Final femoral preparation - Put the L-shape chisel onto the universal handle - Prepare the posterior-stabilised cam space by pushing the L-shape chisel into each side of the guided area Peg preparation - Impact the chisel until it reaches the line corresponding to the size of the guide, thus entrance of the guide - Mark the two peg holes with the drill bit with stop - Note: the pegs can be prepared on the trial femoral component - Remove the 3 headed pins using the pin extractor and extract the preparation guide using the universal handle 25

26 Final femoral preparation - To remove bone ridge between distal cut and reamed notch: - Select an osteotome corresponding to femoral finition guide size - Push the osteotome into each slot (edge of hole for reamer) until it stops Bone cuts Opening for osteotome 26

27 Final femoral preparation - Select the trial femoral component appropriate for the size and side being operated - Impact the femoral trial component using the femoral impactors - If the peg holes have not been prepared yet, this can be done on the trial femoral component using the drill bit with stop 27

28 Preparation of the tibial keel 28

29 Tibial plate preparation - Determine the appropriate trial baseplate size. A smaller or larger size relative to the femur may be selected - Position the trial tibial baseplate onto the tibial cut using the tibial baseplate handle - remove the baseplate handle and place a trial insert ( use the same size as the baseplate) - Then reattach the handle to stabilise the insert onto the tibial baseplate 29

30 Tibial plate preparation - Place the assembly below the trial femoral component and move the knee through a flexion/extension cycle to let the baseplate seat itself underneath it (the handle can be removed) - Choose a different insert thickness if needed - Use electrocautery to mark the baseplate position on the tibia using the two lines on the baseplate - Remove the assembly and replace the baseplate (without the insert) using the marks made on the tibia as a guide - Fix baseplate with two 30 mm headed pins 30

31 Tibial plate preparation - Position the appropriate sized routing guide onto the trial baseplate - A handle can be attached to the guide for tibial stem punch - Ream using the tibial reamer until it stops (same for all sizes) - Impact the appropriate sized tibial stem punch (mounted on universal handle) - Remove the assembly using the pin extractor and handle 31

32 Patellar preparation 32

33 Resurfacing option - Position the patella guide with the lugs facing the anterior face of the patella - Using the adjustment wheel, put the 8 mm sensor in contact with the joint face. The jaws of the guide must be opened - Tighten and lock the guide - Read the residual bone thickness - Perform the resection across the slot - Determine required patella size using the trial patellar components - Centre and impact the drilling gauge - Drill the hole for the 3 pegs - Insert the trial patella and test the patellar tracking - Cement the chosen patella using the patella forceps 33

34 Countersinking option - Determine required patella size using the trial patellar components - Select the clamp size suitable for the patella - Place the patellar joint surface towards the clamp - Tighten the forceps to hold the patella - Ream until the reamer comes into contact with the clamp - Remove the forceps, insert the trial patellar component and evaluate the fit of the patella in the trochlea 34

35 Countersinking option - Place the forceps onto the reaming guide - Cement the chosen patella in place and hold it with the clamp 35

36 Final implantation 36

37 Tibial baseplate implantation - Use the keel wrench to screw the peg into the tibial baseplate (cemented or cementless). - Position the tibial baseplate and impact it using the tibial impactor mounted on the universal handle - The tibial baseplate can be impacted using the impactor/holder: - Screw the impactor/holder onto the tibial component - Place the universal handle onto the impactor/holder - Insert and impact the tibial component - Remove the instrument and finish impacting with the tibial impactor 37

38 Femoral component implantation - Put the chosen femoral component (cemented or cementless) onto the condyle holder - Place the femoral component onto the femoral cuts and impact it into place. Remove the condyle holder - Finish impacting with the condyle impactor 38

39 Tibial insert implantation - Place knee in hyperflexion - Remove protective film from the top of the tibial baseplate - Slide the insert into the posterior baseplate rails, then impact its anterior side using the tibial impactor - Reduce the femoral component onto the insert 39

40 Component extraction Revision option 40

41 Tibial baseplate extraction - To remove the tibial baseplate, use Lambotte osteotomes or bone chisels between the insert and the baseplate - Place the universal handle onto the impactor/holder - Screw impactor onto the tibial baseplate - Gradually extract the component by tapping under the anvil 41