Presentation on theme: "DuringLCA reconstruction Resorbable transcondylar system for femoral fixation."— Presentation transcript:
duringLCA reconstruction Resorbable transcondylar system for femoral fixation
The product ST: Dr. Daniel J. McKernan, Toledo, Ohio, USA BTB: Dr. Paul H. Marks, Toronto, Ontario, CAN Created by:
42 mm 3.3 mm 2.7 mm The Cross Pin Bone-Tendon- Bone Soft-Tissue Material: PLA, Polilactic Acid Reabsorption: 2-4 years Idrolysis (CO 2 + H 2 O)
The instruments Soft Tissue
The instruments Bone-Tendon-Bone
The sterile kit Two pins One interlocking trocar Two sleeves
The sterile kit
Surgical technique Soft Tissue and Bone Tendon Bone Tibial tunnel Femoral half tunnel: mm depth
Surgical technique Harvest the Semitendinosus and Gracilis tendons
Surgical technique Fold the two grafts over a strong suture (Ethibond #4 or 5)
Whip stitch (Ethibond #2) the looped- over part of the graft as shown: it is important to create a secure and compact bundle Surgical technique
Mark the graft at 30 mm for later reference when placing it into the femoral half-tunnel Surgical technique
Choose the femoral rod of the same diameter of the tunnel Attach it to the guide frame Surgical technique
Insert the guide (attached to the appropriate size femoral rod) into the femoral tunnel until it touches the end Surgical technique
Assemble the sleeve over an interlocking trocar: note that the trocar is much longer then the sleeve interlocking trocar sleeve Surgical technique
Note how the trocar blocks itself: the sleeve-trocar assembly can rotate together Surgical technique
Drill the sleeve-trocar assembly through the two holes of the guide into the lateral side of the femur
Surgical technique Remove the guide frame from the knee, leaving only the two sleeves in the lateral aspect of the femur.
Surgical technique Note that a lot of saline solution comes out: this shows the right placement of the sleeves.
Surgical technique To verify furthermore the right placement of the two sleeves, use the scope and a trocar.
Surgical technique Pull the graft into the tunnel using a guide wire
Surgical technique During the graft placement, the saline outflow stops: this shows that the graft has filled the tunnel
Surgical technique Insert the RIGIDfix cross pins into the sleeves using the stepped pin insertion rod and mallet.
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.
Surgical technique Remove the sleeves. The graft is now fixed in the femoral tunnel by two parallel absorbable pins.
Surgical technique Pay attention to remove the sleeves: pull it with the removal-tool in the straight direction, without twisting or bending.
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
Surgical technique Bone Tendon Bone interlocking trocar sleeve Assemble the sleeve over an interlocking trocar: note that the trocar is about so long as the sleeve
Surgical technique Bone Tendon Bone Drill the longer trocar through the femoral sleeves in order to create the holes on the bone plug Pull the graft is inside the half tunnel
SUMMARIZING Femoral half tunnel: mm lenght Place the guide/femoral rod into the femoral half tunnel Drill the two sleeves into the lateral side of the femur Soft Tissue Bone Tendon Bone Pull the graft in place Insert the cross pins Drill the bone plug
The PRESS - FIT
In the ST technique: there is press-fit not hanging on!
7 mm 3.3 mm 10.3 mm 7 mm 10.3 mm 3.3 mm In the ST technique: there is press-fit not hanging on!
30 mm 9 mm 16.5 mm 30 mm 5.8 mm 19.8 mm 10.3 mm 17.8 mm 25 mm The dimensions of femoral rod and B-T-B pins N.B.: 2.7 mm is the diameter of Bone Tendon Bone pins
Ultimate load Stiffness R = 623 N K = 60 N/mm Technical data for ST
Technical data for BTB Ultimate load Stiffness R = 424 N K = 74 N/mm
Cyclic loading tests Average migration 1,4 mm Cyclic loading Load Time 150 N 10 N n = 1000 cicles
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.