Arthrex TightRope Fixation of a Soft Tissue Graft

Introduction

Classically, techniques for all-inside anterior cruciate ligament (ACL) reconstruction involved the use of transtibial drilling of the ACL femoral socket. Although elegant, it does not always provide an anatomical ACL reconstruction. Common pitfalls associated with this technique include a tibial tunnel that is too posterior, as well as a high vertical, anterior, and medial femoral tunnel position, providing poor rotational control. The most common cause of revision ACL reconstruction is technical error on the part of the surgeon, specifically nonanatomic ACL reconstruction.

Although the first generations of all-inside techniques were not ideal, the outside-in technique for creating the femoral socket fell out of favor due to morbidity. However, surgical instrumentation has evolved significantly with the introduction of narrow retrograde drilling pins that curb the associated morbidity of the outside-in technique.

In addition, retrograde drilling pins are an advantage over anteromedial portal drills because they avoid risk of damaging the medial femoral cartilage and do not require a hyperflexed position. Outside-in technique is not constrained and affords the surgeon independent anatomic positioning of the tibial and femoral tunnels. Traditional ACL tunnels require violation of the outer cortices to create full-length tunnels, whereas retrograde drilling provides precise control over tunnel depth, allowing the ability to take the minimal amount of bone required for formation of the socket.

In addition, newer generation suspensory fixation no longer limits the surgeon to a fixed length. The surgeon now has the ability to retension the graft prior to finial fixation.

Surgical Technique

Arthrex (Naples, Florida) TightRope fixation via GraftLink technique requires learning specific graft preparation, socket creation, and of course fixation techniques. Soft tissue hamstring harvest is achieved via the “pluck and run” technique, which affords considerable cosmesis and theoretically decreases postoperative morbidity compared with traditional techniques. When creating graft tunnels or in this case “sockets,” it is important to bear in mind that graft length is less than the sum of the socket length plus the intra-articular graft distance. This is important because it ensures the graft will not bottom out completely in the sockets during final tensioning. For fixation, the senior author uses TightRope RT for femoral suspensory fixation and TightRope ABS for femoral fixation.

Hamstring Graft Harvesting

TightRope fixation can be used with multiple graft selection, such as bone–patellar–bone, autograft, or allograft. For hamstring autograft harvesting, the senior author uses a minimally invasive technique first described by Prodromos et al. This is performed through a small posterior medial incision ( Fig. 65.1 ). The tendons are first palpated in the area of the medial popliteal fossa. A transverse skin incision approximately 2–3 cm is made in line with the popliteal crease skinfold. The popliteal fascia is incised in a longitudinal fashion. This level is such that the semitendinosus is directly inferior to the gracilis and is usually void of muscle tissue when compared with the gracilis ( Fig. 65.2 ).

With the use of a right ankle clamp, the semitendinosus is retrieved and retained by placing a stay suture. Soft tissue attachments are bluntly freed. An open tendon stripper is used to release the proximal tendon ( Fig. 65.3 ). The proximal portion of the graft is then delivered from the wound and stripped of muscular tissue ( Fig. 65.4 ). At this point in time the graft can be whipstitched however desired. Then with the use of a closed tendon stripper, the distal portion of the graft is harvested ( Fig. 65.5 ). Muscle tissue may have to be cleaned from the proximal portion of the graft before inserting the closed tendon stripper and freeing it from its distal insertion. If the semitendinosus graft is at least 27 cm, this can be used in a quadrupled fashion for the complete graft of 70 mm. However, a graft less than this can be augmented with a gracilis, which is harvested in the same fashion.