Single versus double hamstring tendon graft in anterior cruciate ligament (ACL) reconstruction in the paediatric patient

Procedure name: Single hamstring tendon ACL reconstruction Approximate procedure duration: 1.5 hours Two senior surgeons will perform all surgeries at the Queensland Children’s Hospital. Both have been allowed a surgical learning curve of 20 cases (minimum) before the start of the trial. Smith&Nephew (S&N) UltraButton + round ExtendoButton will be used. Tendon harvest and graft preparation: The semitendinosus hamstring tendon be harvested for the single graft technique. A tendon stripper will be used to release the tendons from their proximal attachment via a standard push technique to a length of approximately 22cm. Graft preparation for the single hamstring technique will involve tripling the single semitendinosus tendon over two S&N UltraButton loops (with a round ExtendoButton being attached to the tibial UltraButton). The ends of the tendon complex are sutured via a whip-stitch technique using a #1 Ethibond suture on a J-needle. The prepared tendon complex will be set aside and soaked in a Vancomycin laden Raytec sponge. Once prepared, the graft is measured for both length (to ensure that the graft will adequately span the knee joint and sufficiently pass through both tunnels) and diameter (to determine the required femoral and tibial tunnel diameters for reaming). Knee arthroscopy and tunnel drilling: These are comparable between interventions and therefore will not be elaborated here. Graft passing and fixation: The nylon suture is pulled through the tibial tunnel so that the loop end is exiting out of the tibial tunnel. The graft is orientated and the Ethibond sutures are placed through the nylon loop. The Ethibond sutures are passed through the tibial and femoral tunnels and out of the skin of the anterolateral thigh. The arthroscope is placed into the knee joint and the Ultrabutton loop and graft are pulled into the femoral tunnel under vision to the line drawn on the graft from previous measurements. The Ultrabutton is toggled and flipped on the femoral side. The graft is held taught and the Femoral Ultraloop is reduced pulling the graft into the femoral tunnel to its desired length (~20mm). The knee is then brought out to 30-40 degrees flexion, and the tibial Ultraloop is reduced to pull the graft into the tibial tunnel. Final tensioning of the graft is done with knee extended to 0 degrees flexion the ExtendoButton is secured down to the tibia. Post-operative care and rehabilitation: These are comparable between interventions and therefore will not be elaborated here. Protocol adherence: A data monitoring committee will convene every 6 months to monitor post randomisation protocol adherence, patient safety and treatment efficacy during the surgical stage of the trial.