duringlca reconstruction resorbable transcondylar system for femoral fixation

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during during LCA LCA recon recon s s truction truction R R esorbable transcondyl esorbable transcondyl ar ar system system for femoral fixation for femoral fixation

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Page 1: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

duringduringLCA LCA reconreconsstructiontruction

RResorbable transcondylesorbable transcondylararsystemsystem

for femoral fixationfor femoral fixation

Page 2: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

The productThe product

STST: Dr. Daniel J. McKernan, : Dr. Daniel J. McKernan, Toledo, Ohio, USAToledo, Ohio, USA

BTBBTB: Dr. Paul H. Marks, : Dr. Paul H. Marks, Toronto, Ontario, CANToronto, Ontario, CAN

Created by:Created by:

Page 3: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

42 mm42 mm

42 mm42 mm

3.3

mm

3.3

mm

2.7

mm

2.7

mm

The “Cross Pin”The “Cross Pin”

Bone-Bone-Tendon-BoneTendon-Bone

Soft-TissueSoft-Tissue

Material: PLA, Polilactic AcidMaterial: PLA, Polilactic AcidReabsorption: 2-4 yearsReabsorption: 2-4 yearsIdrolysis (COIdrolysis (CO22 + H + H22O)O)

Page 4: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

The instrumentsThe instrumentsSoft Soft TissueTissue

Femoral rod:7, 8, 9, 10 mm

Page 5: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

The instrumentsThe instrumentsBone-Tendon-BoneBone-Tendon-Bone

Femoral rod:9, 10, 11, 12 mm

Stepped trocar: to drill the bone plug

Page 6: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

The sterile kitThe sterile kitTwo pinsTwo pins

One interlocking trocarOne interlocking trocar

Two sleevesTwo sleeves

Page 7: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

The sterile kitThe sterile kit

Page 8: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Surgical techniqueSurgical techniqueSoft Tissue and Bone Tendon Soft Tissue and Bone Tendon BoneBone

Tibial Tibial tunnel tunnel

Femoral half Femoral half tunnel: 25-30 mm tunnel: 25-30 mm depth depth

Page 9: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Surgical techniqueSurgical technique

Harvest the Semitendinosus and Gracilis Harvest the Semitendinosus and Gracilis tendonstendons

Page 10: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Surgical techniqueSurgical technique

Fold the two grafts over a strong Fold the two grafts over a strong suturesuture(Ethibond #4 or 5)(Ethibond #4 or 5)

Page 11: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Whip stitch (Ethibond #2) the Whip stitch (Ethibond #2) the looped-over part of the graft as looped-over part of the graft as shown: it is important to create a shown: it is important to create a secure and compact bundlesecure and compact bundle

Surgical techniqueSurgical technique

Page 12: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Mark the graft at 30 mm for later Mark the graft at 30 mm for later reference when placing it into the reference when placing it into the femoral half-tunnelfemoral half-tunnel

Surgical techniqueSurgical technique

Page 13: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Choose the Choose the femoral rod of femoral rod of the same the same diameter of the diameter of the tunneltunnel

Attach it to the Attach it to the guide frameguide frame

Surgical techniqueSurgical technique

Page 14: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Insert the guide Insert the guide (attached to the (attached to the appropriate size appropriate size femoral rod) into femoral rod) into the femoral tunnel the femoral tunnel until it touches until it touches the endthe end

Surgical techniqueSurgical technique

Page 15: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Assemble the sleeve over an Assemble the sleeve over an interlocking trocar: note that the interlocking trocar: note that the trocar is much longer then the sleevetrocar is much longer then the sleeve

interlocking trocar sleeve

Surgical techniqueSurgical technique

Page 16: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Note how the trocar blocks itself: the Note how the trocar blocks itself: the sleeve-trocar assembly can rotate sleeve-trocar assembly can rotate togethertogether

Surgical techniqueSurgical technique

Page 17: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Surgical techniqueSurgical technique

Drill the Drill the sleeve-sleeve-trocar trocar assembly assembly through the through the two holes of two holes of the guide the guide into the into the lateral side lateral side of the femurof the femur

Page 18: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Surgical techniqueSurgical technique

Remove the Remove the guide frame guide frame from the from the knee, leaving knee, leaving only the two only the two sleeves sleeves in the in the lateral aspect lateral aspect of the femur.of the femur.

Page 19: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Surgical techniqueSurgical technique

Note that a lot of saline solution Note that a lot of saline solution comes out: this shows the right comes out: this shows the right placement of the sleeves.placement of the sleeves.

Page 20: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Surgical techniqueSurgical technique

To verify furthermore the right placement To verify furthermore the right placement of the two sleeves, use the scope and a of the two sleeves, use the scope and a trocar.trocar.

Page 21: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Surgical techniqueSurgical technique

Pull the graft Pull the graft into the into the tunnel using tunnel using a guide wirea guide wire

Page 22: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Surgical techniqueSurgical technique

During the graft placement, the saline During the graft placement, the saline outflow stops: this shows that the graft outflow stops: this shows that the graft has filled the tunnelhas filled the tunnel

Page 23: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Surgical techniqueSurgical technique

Insert the RIGIDfix Insert the RIGIDfix cross pins into the cross pins into the sleeves using the sleeves using the stepped pin insertion stepped pin insertion rod and mallet.rod and mallet.

Page 24: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Surgical techniqueSurgical technique

During the pin insertion the surgeon During the pin insertion the surgeon feels the press-fit sensation: the pin feels the press-fit sensation: the pin crosses through the soft tissue fibers crosses through the soft tissue fibers and presses them towards the tunnel and presses them towards the tunnel surface.surface.

Page 25: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Surgical techniqueSurgical technique

Remove the Remove the sleeves.sleeves.The graft is now The graft is now fixed in the fixed in the femoral tunnel femoral tunnel by two parallel by two parallel absorbable pins.absorbable pins.

Page 26: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Surgical techniqueSurgical technique

Pay attention to remove the sleeves: Pay attention to remove the sleeves: pull it with the removal-tool in the pull it with the removal-tool in the straight direction, without twisting or straight direction, without twisting or bending.bending.

Page 27: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Surgical technique

Bone Tendon Bone

Graft the central Graft the central third from the third from the patellar tendonpatellar tendon

Place one drill Place one drill hole in the hole in the femoral plug for femoral plug for application of a application of a stay suturestay suture

Page 28: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Surgical techniqueBone Tendon Bone

interlocking trocar sleeve

Assemble the sleeve over an Assemble the sleeve over an interlocking trocar: note that the interlocking trocar: note that the trocar is about so long as the sleevetrocar is about so long as the sleeve

Page 29: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Surgical techniqueSurgical technique

Bone Tendon Bone Tendon BoneBone

Drill the longer trocar through Drill the longer trocar through the femoral sleeves in order to the femoral sleeves in order to create the holes on the bone create the holes on the bone plugplug

Pull the graft is inside the half Pull the graft is inside the half tunnel tunnel

Page 30: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

SUMMARIZINGSUMMARIZINGFemoral half tunnel: 25-30 mm Femoral half tunnel: 25-30 mm lenghtlenght

Place the guide/femoral rod into the femoral half Place the guide/femoral rod into the femoral half tunneltunnel

Drill the two sleeves Drill the two sleeves into the lateral side of into the lateral side of the femurthe femur

Drill the two sleeves Drill the two sleeves into the lateral side of into the lateral side of the femurthe femur

Soft TissueSoft Tissue Bone Tendon Bone Tendon BoneBone

Pull the graft in placePull the graft in place Pull the graft in placePull the graft in place

Insert the cross pinsInsert the cross pins

Insert the cross pinsInsert the cross pins

Drill the bone plugDrill the bone plug

Page 31: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

The The PRESSPRESS--FITFIT

Page 32: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

In the ST technique:In the ST technique:there is “press-fit” not “hanging on”!there is “press-fit” not “hanging on”!

Page 33: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

7 m

m3

.3 m

m

10

.3 m

m

7 mm 7 mm

10

.3 m

m

3.3

mm

In the ST technique:In the ST technique:there is “press-fit” not “hanging on”!there is “press-fit” not “hanging on”!

Page 34: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

30

mm

9 m

m

16

.5 m

m

30

mm

5.8

mm

19

.8 m

m

10

.3 m

m

17

.8 m

m

25 mm

The dimensions of femoral rodThe dimensions of femoral rodand B-T-B pinsand B-T-B pins

N.B.: 2.7 mm is the diameter of Bone Tendon Bone pins

Page 35: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Ultimate loadUltimate load

0

100

200

300

400

500

600

700

Ultimate load for ST (Newton)

RIGIDfixEndoButtonTransFix

0

20

40

60

80

100

120

Stiffness for ST (N/mm)

RIGIDfixEndoButtonTransFix

StiffnessStiffness

R = 623 NR = 623 N

K = 60 N/mmK = 60 N/mm

Technical data for STTechnical data for ST

Page 36: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Technical data for BTBTechnical data for BTB

Ultimate loadUltimate load

0

10

20

30

40

50

60

70

80

90

Stiffness for BTB (N/mm)

RIGIDfixBioScrew

StiffnessStiffness

0

100

200

300

400

500

600

Ultimate load for BTB (Newton)

RIGIDfixBioScrew

R = 424 NR = 424 N

K = 74 K = 74 N/mmN/mm

Page 37: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Cyclic loading testsCyclic loading tests

Average migrationAverage migration

0.14

0.43

1.12

1.40

2.09

2.38

3.07

3.36

Migration for ST (mm)

RIGIDfixEndoButtonTransFix

1,4 mm1,4 mm

Cyclic Cyclic loadingloading

LoadLoad

TimeTime

150 N150 N

10 N10 N

n = 1000 ciclesn = 1000 cicles

Page 38: DuringLCA reconstruction Resorbable transcondylar system for femoral fixation

Orientation Orientation teststests

The ST tendons are whipstitched at the looped The ST tendons are whipstitched at the looped end, forming a tight bundle that is “press-fit” end, forming a tight bundle that is “press-fit” placed into the femoral tunnel. This allows placed into the femoral tunnel. This allows RIGIDfix absorbable pins to cross the graft in RIGIDfix absorbable pins to cross the graft in any plane and provide rigid fixation.any plane and provide rigid fixation.