In all cases, we use the regular knee arthroscopic surgery procedure and the standard anterolateral ... read more ↘ portal (ALP) and an anteromedial portal (AMP; the latter just above the anterior horn of the internal meniscus) to view and confirm the tears. Once the ACL complete tear is assessed, the autologous hamstring tendons (gracilis and semitendinosus) are harvested. Both tendons are folded in two to double the thickness of each bundle and to obtain a diameter of 6–7 mm for PL bundle (gracilis) and of 7–9 mm for AM bundle (semitendinosus). Once the femoral and tibial insertions are measured—in order to confirm the anatomical indication for the technique— the AM femoral tunnel is drilled through the AMP with the knee flexed at 95–100°. The insertion site is located using a Kirschner wire at 10:30–11:00 clockwise for the right knee and at 13:30–14:00 clockwise for the left knee; the most posterior position is selected in order to preserve a 2-mm distance from the tunnel with respect to the posterior wall of the external femoral condyle’s internal face. The tunnel is completely drilled and measured using the regular EndoButton CL technique (Smith & Nephew Endoscopy, Andover, MA), and a suture thread is passed through and left into the tunnel. At this point, we switch arthroscopic portals in order to use AMP as the viewing portal and ALP as the working portal. The specific femoral aimer is then inserted to drill the PL femoral tunnel outside-in from ALP. Once the ball at the far end of the aimer is placed in the AM tunnel—previously drilled—an 11mm distance is preserved from the central point of both tunnels, so the ball can be accommodated inside the femoral tunnel and there- fore increase or reduce the inter-tunnel distance. The aimer is placed externally, in the three space dimensions, at approximately 2 cm from the external epicon- dyle of the femur. The PL femoral tunnel is performed outside-in inserting a Kirschner wire and using a cannu- lated reamer. Once the tibial entry point was localized at the centre of the footprint or slightly posterior to the insertion of the anterior horn of the external meniscus, a tibial tunnel is performed adopting the standard technique, with a single-bundle drill guide (Smith & Nephew Endoscopy, Andover, MA) and preserving the intra-articular borders of the tibial footprint. The angulation of the tibial tunnel should be 50° in the sagittal plane and 30° in the coronal one. Once the three tunnels have been created, the suture threads in both femoral tunnels are retrieved trough the tibial tunnel, and the gracilis tendon for the PL bundle is inserted in first place. Afterwards, the semitendinosus tendon is also inserted using the standard technique for bundle fixation with EndoButton CL (Smith & Nephew Endoscopy, And- over, MA). Tibial fixation is then carried out with the knee flexed at 40° using a Biosure (Smith & Nephew Endoscopy, Andover, MA) interference screw 1 mm wider than the tunnel’s size. Finally, with the knee flexed at 20°, the PL bundle is fixed with another interference Biosure (Smith & Nephew Endoscopy, Andover, MA) screw, inserted outside-in, and also 1 mm upsized than the tunnel’s diameter. All patients followed the same postoperative rehabilitation protocol, consisting on immediate partial weight bear- ing, protected by a brace in full extension for 3 weeks. Immediate mobility of 0–30° was allowed during the first week, and of 0–60° between weeks 2 and 3. Free movement and closed kinetic chain exercises were permitted at 3 weeks, cycling at 6 weeks, and straight, flat surface running at 12 weeks.
STEPS 1. VIEW AND VERIFICATION OF THE FEMORAL INSERTION SIZE THROUGH AMP. 2. CREATION OF THE AM FEMORAL TUNNEL THROUGH THE AMP USING A “LOW” STANDARD TECHNIQUE. 3. PORTALS ARE SWITCHED AND PL FEMORAL TUNNEL IS DRILLED OUTSIDE-IN USING A SPECIFIC AIMER THROUGH ALP. 4. STANDARD TIBIAL TUNNEL DRILLING. 5. BUNDLE FIXATION: FIRST, AM AS PER STANDARD ENDOBUTTON; SECOND, BOTH BUNDLES IN THE TIBIAL TUNNEL WITH A SCREW; AND, FINALLY, THE PL BUNDLE WITH ANOTHER SCREW OUTSIDE-IN.
