1. Resorbable transcondylar
system
for femoral fixation
during
LCA
reconstruction

2. The product Created by: ST: Dr. Daniel J. McKernan, Toledo, Ohio, USA
BTB: Dr. Paul H. Marks,
Toronto, Ontario, CAN

3. The “Cross Pin” Bone-Tendon-Bone Soft-Tissue
2.7 mm
Bone-Tendon-Bone
42 mm
3.3 mm
Soft-Tissue
42 mm
Material: PLA, Polilactic Acid
Reabsorption: 2-4 years
Idrolysis (CO2 + H2O)

4. The instruments
Soft Tissue

5. The instruments
Bone-Tendon-Bone

6. The sterile kit
Two pins
One interlocking trocar
Two sleeves

7. The sterile kit

8. Surgical technique Soft Tissue and Bone Tendon Bone
Femoral half tunnel: mm depth
Tibial tunnel

9. Surgical technique
Harvest the Semitendinosus and Gracilis tendons

10. Surgical technique Fold the two grafts over a strong suture
(Ethibond #4 or 5)

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

12. Surgical technique
Mark the graft at 30 mm for later reference when placing it into the femoral half-tunnel

13. Surgical technique
Choose the femoral rod of the same diameter of the tunnel
Attach it to the guide frame

14. Surgical technique
Insert the guide (attached to the appropriate size femoral rod) into the femoral tunnel until it touches the end

15. Surgical technique
Assemble the sleeve over an interlocking trocar: note that the trocar is much longer then the sleeve
interlocking trocar
sleeve

16. Surgical technique
Note how the trocar blocks itself: the sleeve-trocar assembly can rotate together

17. Surgical technique
Drill the sleeve-trocar assembly through the two holes of the guide into the lateral side of the femur

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

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

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

21. Surgical technique
Pull the graft into the tunnel using a guide wire

22. Surgical technique
During the graft placement, the saline outflow stops: this shows that the graft has filled the tunnel

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

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

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

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

27. Surgical technique Bone Tendon Bone
Graft the central third from the patellar tendon
Place one drill hole in the femoral plug for application of a stay suture

28. Surgical technique Bone Tendon Bone
Assemble the sleeve over an interlocking trocar: note that the trocar is about so long as the sleeve
interlocking trocar
sleeve

29. Surgical technique Bone Tendon Bone
Pull the graft is inside the half tunnel
Drill the longer trocar through the femoral sleeves in order to create the holes on the bone plug

30. SUMMARIZING Femoral half tunnel: 25-30 mm lenght
Place the guide/femoral rod into the femoral half tunnel
Soft Tissue
Bone Tendon Bone
Drill the two sleeves into the lateral side of the femur
Drill the two sleeves into the lateral side of the femur
Pull the graft in place
Pull the graft in place
Insert the cross pins
Drill the bone plug
Insert the cross pins

31. The PRESS-FIT

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

33. there is “press-fit” not “hanging on”!
In the ST technique:
there is “press-fit” not “hanging on”!
7 mm
7 mm
3.3 mm
10.3 mm
3.3 mm
10.3 mm
7 mm

34. The dimensions of femoral rod
and B-T-B pins
5.8 mm
9 mm
10.3 mm
16.5 mm
17.8 mm
19.8 mm
30 mm
30 mm
25 mm
N.B.: 2.7 mm is the diameter of Bone Tendon Bone pins

35. Technical data for ST
Ultimate load
R = 623 N
Stiffness
K = 60 N/mm

36. Technical data for BTB
Ultimate load
R = 424 N
Stiffness
K = 74 N/mm

37. Cyclic loading tests Cyclic loading Average migration 1,4 mm Load
n = 1000 cicles
150 N
10 N
Time
Average migration
1,4 mm

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