Ipsilateral PTG ACL Reconstruction ProcedureProfessor Sanjiv Jari30th March 2016
An examination under anaesthetic assesses the laxity of all of the ligaments in the knee and records knee motion.
The knee is prepared and draped under sterile conditions. 20mls of local anaesthetic with adrenaline is injected into the portal sites and knee joints as pre-emptive analgesia. A tourniquet is elevated around the limb to allow a bloodless field for the operation.
An arthroscopy of the knee joint assesses and deals with any other damage within the knee such as meniscus tears or chondral damage and also clears the ACL stump from the knee if appropriate at this stage.
The limb is re-prepared and draped. A small medial open incision is made to allow exposure of the knee joint and specifically of the anterior cruciate ligament. Special retractors are used within this minimal incision to allow full exposure of the ACL.
The ACL stump is cleared out to allow space for the new ligament to be placed. The intercondylar notch containing the anterior and posterior cruciate ligaments is widened on the lateral side to allow a gap of 10 to 11mm between the posterior cruciate ligament and the lateral wall or insertion point of the anterior cruciate ligament.
A free hand guide wire is placed into the tibia from the outside into the centre of the knee so that it enters the knee in the correct position of the ACL footprint. This tunnel is over-drilled to 10mm. The position of the tunnel is posteriorised with a series of curettes to get the tunnel in exactly the correct position.
The reamings from the drilling and curetting are collected and stored for use later in the operation.
A guide wire is placed freehand into the anatomically correct footprint of the femoral side of the ACL. This is done independently and not through the tibial tunnel. The advantage of independent placements is that it can be exactly accurate and is not limited by the tibial tunnel. If the tibial tunnel is in the wrong position this will magnify the error making the femoral tunnel also in the wrong position. By re-reaming the tibial tunnel if the wire is going through it for the femoral side it can also widen this tibial tunnel unnecessarily and so potentially compromising the fixation of the graft.
The femoral tunnel is a blind ending tunnel which is reamed to an appropriate depth to allow placement of the graft so that the tibial bone block is near the tibial joint surface.
Once again the bone reamings and drillings are collected. The individual tunnel lengths are measured. Once the length of the tunnel is known a graft of the appropriate size can be harvested.
Through the same incision a central third of the patellar tendon, taking bone blocks at the patella and tibial ends, are harvested. This graft is 10mm wide as a minimum. The bone blocks at each end are drilled with three holes through and three strong sutures are passed into each bone block.
The graft is measured as are the lengths of each bone block. The bone tendon interfaces are marked.
A special passing drill is used to pass the graft into the pre-drilled tunnels. The graft is advanced so that the bone block on the tibial side is just below the tibial articular surface.
The femoral bone block is fixed with an interference screw.
The knee is extended to ensure that there is full hyperextension of the knee with no impingement in the notch. The knee is placed at 30° of flexion and the tibial bone block is fixed with either an interference screw or cortical button. The knee is put through a full range of motion to ensure full hyperextension and full flexion is present and the fixation re-tensioned as appropriate.
The tourniquet is released and the bleeding is cauterised. The knee is washed out.
The defect in the patellar tendon is approximated and closed. The bone plug harvest sites in the tibia and patella are bone grafted with the previously collected reamings.
The incision into the knee capsule is closed. Local anaesthetic is infiltrated into the wounds as well as into the knee joint. 10mls of Viscoseal is also placed in the knee.
A full length compression stocking is placed on the knee over which a cold compression device is applied.
The postoperative infusion of intravenous anti-inflammatory medication is administered for a 24 hour period. The knee is placed on a CPM machine.