A Comparison of the Outcomes of Quadriceps Autograft versus Hamstring Autograft For Use In Anterior Cruciate Ligament (ACL) Reconstruction

This is a randomised control trial comparing the outcomes of a quadriceps autograft versus a hamstring autograft for the treatment of ACL deficient knees in patients older than 15 years. The Surgery will be performed by a Senior Consultant Orthopaedic Surgeon with at least 5 years experience. The patients will have an arthroscopic examination of the knee to ensure that they do not have any of the exclusion criteria. Then once they are determined to be eligible for the study an envelope will be opened which determines if a quadriceps or a hamstring tendon will be harvested. The ACL reconstruction will then be performed with the selected tendon. There is no significant difference in the time taken to harvest the quadriceps versus the hamstring tendon, with an approximate time of 45 minutes. Hamstrings: The Semitendinosus tendon is harvested from a 3 cm longitudinal incision over the pes anserine tendon origin utilizing an open tendon stripper. The Semi-tendinosis tendon is harvested and if a sufficient diameter and length was achieved, (length of at least 28cm and quadrupled diameter of at least 8 mm) the gracilis was left. However, if the length is not sufficient then the gracilis is harvested as well. The Semitendinosis is then prepared by incorporating the ABS tightrope. This is achieved by doubling up the tendon and whip stitching the ends together utilizing a fibre loop. The double loop is then quadrupled incorporating the RT tightrope. A 0 fibrewire suture is then placed 2cm from the end of the tendon at each end of the tendon. The suture goes through all the tendons and is then lopped around the graft. A so-called triple/double graft is prepared if both the gracilis and Semi-Tendinosus are prepared. Quadriceps: A full-thickness central slip of quadriceps tendon is harvested through a 3cm longitudinal incision over the proximal pole of the patella. A 10x7 mm Arthrex double blade is used to cut the central slip. The distal aspect is then released with a 15 Blade and the Cigar cutter utilized to strip proximally to a length of 7 cm and then cut. The proximal end is attached to an ABS tightrope using a fibrelink and the proximal aspect attached to a RT tightrope also utilizing a fibrelink. Preparation and drilling of tunnels: The ACL footprint in the notch is cleared with a shaver and electrocautery device to clearly see the back of the femoral condyle. The tibial stump of the ACL is removed. For both techniques after graft harvest: A 6/9 outside–in guide from Arthrex is utilized to place the femoral tunnel in the IDEAL position. The IDEAL femoral tunnel position aims to; replicate the most isometric fibres within the native ACL, be localized in the direct fibre subsection of the ACL origin base, be equidistant from the bottom and top of the notch with a tunnel back wall that is 1mm thick and eccentrically located high and deep within the footprint, be anatomic in position, and achieves a low tension-flexion pattern in the ACL graft, thus replicating the native tension-flexion behavior of the ACL. A flipcutter from Arthrex utilized to retrograde drill a tunnel of the measured diameter of the graft to a length of 25 mm. A fibrestick suture is passed and the loop is temporarily retrieved out of the lateral portal. An Arthrex tibial guide is used to drill an antegrade tunnel. The tibial guide angle is set at 55 degrees. A guide pin is inserted first and this is followed by a reamer diameter corresponding to the graft diameter plus 0.5mm, to help pull the graft through the tibia. The Femoral loop-passing suture is then retrieved through the tibial tunnel and the graft is delivered through the tibia into the femur. The RT button is flipped and pulled 1.5 cm into the femoral tunnel. The ABS button is then placed on the tibial side and tensioned ensuring 2 cm of length is in the tibial tunnel. Final tensioning of the RT button is then performed, pulling a further 5 mm into the femoral socket with the knee extended. All surgeons will undergo cadaver training prior to the commencement of the study to ensure uniformity of surgical technique. Post-operatively the patients will all undergo a standardised physiotherapy programme regardless of the tendon used for the reconstruction. Initially this consists of static quadriceps and hamstring exercises. Over the first 6 weeks gradual progression of range of motion, weight bearing progression and active assisted range quadriceps and hamstrings exercises. From 6 weeks onwards focus on strengthening and proprioceptive exercises. Physiotherapy will continue up to 6 months. This will be a multi-centre randomised controlled trial with locations in Whangarei, Auckland and Christchurch. The patients will have routine post-operative follow-ups at a prescribed time. There will be specific measurements of the stability of the reconstruction and strength testing of both the hamstrings and the quadriceps at the 1 year and 2 year mark