Table 1.
Pearls and Pitfalls
| Surgical Step | Pearls | Pitfalls |
|---|---|---|
| Graft harvest | ||
| Tibial tuberosity | The surgeon should harvest a bone block that is no longer than 20 mm because it could exceed the total tunnel length. | If the distal bone block overhangs the tibial tunnel, a curved chisel can be used to create a socket within the tibia, allowing the bone block to seat flush with the tibial cortex. |
| Patella | The surgeon should avoid harvesting a superficial bone block from the distal patella when using the oscillating two-thirds toothed hollow saw. | The upper edge of the hollow saw can be pressed down to the level of the insertion of the patellar tendon during harvesting. |
| Femoral tunnel | ||
| Drilling | The surgeon should set the femoral FlipCutter guide to 115°-120° to avoid a killer angle of the femoral tunnel. This eases press-fit insertion of the bone block. | A suture grasper can be used to exactly align the bone block with the entrance of the femoral tunnel before the TightRope is pulled. |
| Socket length | The length of the socket should exceed the total length of the bone block by about 2 mm. | Because the femoral socket is oval, the bone block cannot be fully seated into the tunnel if the length exactly matches the length of the femoral bone block. |
| Tibial tunnel | The use of a 60° aimer ensures sufficient tibial tunnel length. | When the tibial tunnel is short, care must be taken so that the total graft length does not exceed the tunnel length, with the tibial bone block overhanging the tunnel entrance. |
| Graft preparation | The surgeon should place the drill hole centrally within the patellar bone block. | A drill hole placed too proximally might lead to breakage of the bone block when the BTB TightRope is pulled. |
| Graft insertion | When the 9.4-mm trephine is used for harvesting, dilating the tibial tunnel entrance to 10 mm (i.e. with a 10-mm drill tip) facilitates introducing the graft into the tibial tunnel. | It is essential to fully seat the bone block into the femoral socket before shortening the loop strands; otherwise, the bone block might become stuck at the tunnel entrance. |
| Graft fixation | Using a low medial portal (as in the anteromedial drilling technique) with a femoral tunnel at 115°-120° provides the possibility of using an interference screw for femoral fixation if a small and superficial bone block has been harvested. |