**5.1 The transtibial technique**

Rosenberg is the surgeon who introduced the transtibial technique for ACL reconstruction (Rosenberg & Deffner, 1997; Rosenberg & Brown, 1997; Chen et al., 2003). We will briefly summarize the technique. In a first step, regardless the nature of the graft, a specific tibial drill guide is used to insert a 2.4mm guide wire in the foot of the ACL tibial footprint. In the sagittal plane, a 55° angle orientation with regard to the plane of the tibial plateau is recommended (Fig. 5A). In the coronal plane the guide wire is inserted 1.5cm medial to the tibial tubercle (Fig. 5B), above the pes anserinus tendons, and oriented at 25° with regard to the tibial axis (75° with regard to the tibial plateau surface). The guide wire is then used to guide a cannulated drill bit which diameter corresponds to the graft diameter (Fig.5C).

Fig. 5. Transtibial technique, tibial steps. A: insertion of the tibial guide wire at 55 degree inclination with regard to the tibial plateau plane. B: the starting point of the guide wire is just medial to the tibial tubercle. C: a cannulated drill, which size corresponds to the graft diameter is passed on the guide wire. The knee is maintained at 90 degree of flexion.

In a second step, with the knee bent at 90° of flexion, a femoral guide is introduced through the tibial tunnel inside the intercondylar notch region. The femoral guide has a hook at its intra articular tip which offset (3-9mm) is chosen according to the size of the knee and where the surgeon decides to drill the femoral tunnel in relation with the ACL femoral footprint

Before the early 1990's most of the ACL reconstruction were performed through medial arthrotomy which became with time mini arthrotomy. However, arthroscopic reconstruction (Paulos et al., 1991) undergone rapid development. Although achievement of stability has been well-documented in open ACL reconstructive procedures, it quickly appeared arthroscopically assisted ACL reconstruction offered significantly diminished morbidity, and more predictable rehabilitation after surgery. Improvements in

Rosenberg is the surgeon who introduced the transtibial technique for ACL reconstruction (Rosenberg & Deffner, 1997; Rosenberg & Brown, 1997; Chen et al., 2003). We will briefly summarize the technique. In a first step, regardless the nature of the graft, a specific tibial drill guide is used to insert a 2.4mm guide wire in the foot of the ACL tibial footprint. In the sagittal plane, a 55° angle orientation with regard to the plane of the tibial plateau is recommended (Fig. 5A). In the coronal plane the guide wire is inserted 1.5cm medial to the tibial tubercle (Fig. 5B), above the pes anserinus tendons, and oriented at 25° with regard to the tibial axis (75° with regard to the tibial plateau surface). The guide wire is then used to guide a cannulated drill bit which diameter corresponds to the graft diameter (Fig.5C).

A B C

Fig. 5. Transtibial technique, tibial steps. A: insertion of the tibial guide wire at 55 degree inclination with regard to the tibial plateau plane. B: the starting point of the guide wire is just medial to the tibial tubercle. C: a cannulated drill, which size corresponds to the graft diameter is passed on the guide wire. The knee is maintained at 90 degree of flexion.

In a second step, with the knee bent at 90° of flexion, a femoral guide is introduced through the tibial tunnel inside the intercondylar notch region. The femoral guide has a hook at its intra articular tip which offset (3-9mm) is chosen according to the size of the knee and where the surgeon decides to drill the femoral tunnel in relation with the ACL femoral footprint

**5. The evolution of ACL reconstruction** 

**5.1 The transtibial technique** 

instrumentation allowed refining the precision of the technique.

Fig. 6. Transtibial technique, femoral steps. A: An endofemoral guide wire is introduced through the tibial tunnel. The knee remains bent at 90 degree. The hook located at the proximal tip has variable offset with regard to the shaft of the aimer (X mm). An eyelet needle is drilled through the lateral femoral condyle. This drawing perfectly illustrates the fact one can't reach the center of the ACL femoral footprint with the transtibial technique. B: An endoscopic cannulated drill is passed on the on the guide wire drilling a femoral socket at the desired depth. During drilling, the tibial tunnel is widened by the drill.

(Fig. 6). A long guide wire with an eyelet is inserted with the help of the femoral guide, through the lateral femoral condyle, breaching the lateral cortex until it passes through the skin of the lateral side of the thigh. The femoral guide is removed keeping the guide wire in the condyle. Then, maintaining the knee at 90° of flexion, a cannulated endoscopic drill, which head is the cutting part and the shaft smaller, is threaded on the guide wire through the tibial tunnel, the intercondylar notch, the lateral femoral condyle at a depth which depends on graft type and fixation type. The diameter of the endoscopic drill is chosen according to the graft diameter. The eyelet of the guide wire is used to pull a loop suture through the tibial tunnel, the intercondylar notch and the tibial tunnel exiting on the lateral side of the thigh. The loop stitch is use do pull the graft until it settles in the femoral tunnel and fixed appropriately either with an interference screw, an Endobutton or with cross pins. Then the graft is put under Manual tension; the knee is cycled from full extension to full flexion at least 20 times. The length variation of the graft at the exit of the tibial tunnel is measured and the graft fixed in the tibia either with an interference screw or using extra cortical fixation: button or screw post and washer. The knee flexion at fixation depends on the graft length variation: the larger is the length variation, closer to extension the fixation must be done in order to avoid extension deficit.

As the reader will notice the "clock-face" reference do determine the tunnel position is not used in this chapter. Although this reference has been widely accepted in the literature to describe femoral tunnel positioning it has generated more confusion than clarification (Fu, 2008; Van Eck et al., 2010). The "clock-face" system is based on radiographs of the knee in extension while ACL reconstruction is performed at 90 degree of flexion or more. Therefore

Contemporary Anterior Cruciate Ligament Reconstruction 205

assist the orthopaedic surgeon in assessing the current success of single-bundle reconstruction. The primary factors assessed were tibial subluxation and side-to-side differences in laxity. Secondary outcomes included concomitant injuries and treatments, complications, graft failure, range of motion, and radiographic evidence of degenerative changes. In this review of 1024 single-bundle anterior cruciate ligament reconstructions, including HS and BTPB autografts, 495 concomitant meniscal tears, 95 chondral injuries, and 2 posterior cruciate ligament tears were noted. The complication rate was 6%, and graft failure 4%. Reported pivot-shift test results were negative in 81% of cases; reported Lachman tests were negative in 59% cases; and KT-1000 arthrometer side-to-side differences were < 5 mm in 86% of cases. Flexion and extension deficits were reported in 9 of 11 studies through mean range of motion or deficit ranges. Radiographic changes of articular surface were observed in 7% of the knees at follow-up. The authors concluded this systematic review of a significant body of unbiased outcome data on single-bundle ACL reconstruction demonstrates it to be a safe, consistent surgical procedure affording reliable results. On the other hand, there was still 19%persisting positive pivot shift tests (5-32%), 41% positive Lachman tests (14-76%), and 29% KT1000 side-to-side difference > 3mm (10- 54%). It appears the range of the values is quite variable from one publication to another. This is related to subjective bias when evaluating the patients. If one considers the persistence of a positive pivot shift test as a criterion for anatomic failure, single bundle transtibial ACL reconstruction has failed to restore a normal knee kinematic in 5 to 32% of the cases. The KT1000 arthrometer, which is certainly the most objective test method, showed almost 30% of anatomical failures. Accordingly one may questions the validity of single bundle

transtibial ACL reconstruction which lead to 30% of anatomic failures.

seems to be more frequently met after BPTB graft than after HS grafts.

mostly based on the drawbacks of the transtibial technique

Regardless the graft types (allograft vs autograft**)**, graft source (bone patellar tendon bone, hamstring or Achilles tendon**)**, some significant factors influence the outcome (Kowalchuk et al., 2009) of single bundle reconstruction: lower patient-reported outcome is strongly associated with obesity (BMI>30), smoking, meniscectomy and severe chondrosis at time of surgery. Also, a more vertical orientation of the graft influences the occurrence of a residual

In the long term range, following BPTB, good results are maintained at 15 years after surgery with respect to ligamentous stability, subjective outcomes, and range of motion while kneeling pain remains a significant problem. Concern remains regarding the incidence of further anterior cruciate ligament injury (24% sustained contralateral ACL ruptures, and 8% ruptured the graft). Graft rupture was associated with a graft inclination angle <17°. Contralateral anterior cruciate ligament rupture was associated with age<18 years at time of primary injury. There is increasing number of patients (51%) with radiographic and clinical signs of osteoarthritis despite surgical stabilization (Hui et al., 2011). The joint degeneration

Several surgeons, who early recognized the need to further improve the outcome of ACL reconstruction, moved towards a more anatomic way to reconstruct the ACL. This was

**5.2.2 Factors influencing the outcome** 

pivot shift test (Pinczewski et al., 2008).

**6. The move toward anatomy** 

the orientation of the clock face is no longer valid as the ACL femoral insertion site moves from vertical to horizontal when the knee bends. Furthermore the intercondylar notch is a 3 dimensional structure while the clock-face refers to a 2-diemnsional structure which is neglectful of the depth of the notch.

Fig. 7. Passing the graft. A: the leading stiches of the graft are first pulled through the tibial and femoral tunnel with the help of the eyelet guide wire. B: the graft is then pulled through the tunnels until it fills the femoral tunnel.

As the whole reconstruction procedure is performed through a small tibial incision which is used for harvesting and drilling, the transtibial technique is also called "one-incision" technique. Alternatively, "two-incision" technique has been developed. With this technique a lateral thigh incision is performed in order to settle, behind the lateral femoral condyle, a rear entry femoral guide, which position is arthroscopically controlled. The guide wire and the tunnel drilling are then performed from outside in. With the "twoincision" technique, the position of the femoral guide wire is independent from the tibial tunnel. However, due to the lateral thigh incision and its associated morbidity, the "twoincision" technique has never known a large development. On the contrary, the oneincision technique has quickly spread worldwide. With appropriate instruments "oneincision"ACL reconstruction with quadrupled hamstring tendons can be performed in less than 30 minutes in skilful hands.
