- Email: [email protected]
Anatomic anterior cruciate ligament reconstruction: The French experience
Anatomic Anterior Cruciate Ligament Reconstruction: The French Experience Pascal Christel, MD, PhD,*,† Jean Pierre Franceschi, MD,† Abdou Sbihi, MD,‡ Philippe Colombet, MD,§ Patrick Djian, MD,*,储 and Guy Bellier, MD储 Anatomical observation and biomechanical studies have shown that the anterior cruciate ligament (ACL) mainly consists of 2 distinct bundles, the anteromedial bundle (AMB) and posterolateral bundle (PLB). These 2 bundles have different roles in the control of knee stability. The AMB essentially controls the anterior tibial translation, whereas the PLB mainly controls the rotatory stability of the knee by limiting the internal rotation of the lateral tibial plateau. Current techniques for reconstruction do not completely reproduce the anatomy and function of the ACL. They address only the anteromedial bundle, which does not fully restore ACL function throughout the arc of motion. Current grafts control the anterior tibial subluxation near extension but are less efficacious in providing rotatory stability. Recently several authors have suggested reconstructing not only the anteromedial bundle, but also the posterolateral bundle. After discussing the relevant anatomical and biomechanical data, this article describes a double-bundle ACL reconstruction technique using hamstring tendons routed through 2 tibial and 2 femoral independent tunnels. Short-term results of this technique are encouraging; however, long-term follow-up studies are needed to compare the outcome of a more physiologic double-bundle ACL reconstruction with single-bundle techniques. Oper Tech Orthop 15:103-110 © 2005 Elsevier Inc. All rights reserved. KEYWORDS anterior cruciate ligament, ACL biomechanics, ligament bundles, ACL reconstruction, twin-tunnel technique
A
s a result of better understanding of its anatomy and biomechanical function, reconstruction of the anterior cruciate ligament (ACL) has been increasingly successful during the past 15 years. The use of arthroscopy permits precise positioning of the graft. In addition, the use of strong grafts and fixation systems has resulted in reliable functional results for this procedure. Nevertheless, a review of the literature shows that simple ACL reconstruction by bone-patellar-tendon-bone graft results in insufficient long-term outcomes (Grades C and D, International Documentation Knee Committee [IKDC] system) in 11% to 30% of the cases1-3 and, more importantly, in the persistence of pivot shift
*Department of Orthopaedic Surgery, Institut de l’Appareil Locomoteur Nollet, Paris, France. †Hôpital Privé Paul d’Egine, Champigny-sur-Marne, France. ‡Service du Professeur Curvale, Hôpital de la Conception, Marseille, France. §CCOS Mérignac, France. 储Cabinet Goethe, Paris, France. Address reprint requests to Pascal Christel, MD, PhD, Institut de l’Appareil Locomoteur Nollet, 23, rue Brochant, 75017 Paris, France. E-mail: [email protected]
1048-6666/05/$-see front matter © 2005 Elsevier Inc. All rights reserved. doi:10.1053/j.oto.2004.11.008
(Grade B, IKDC system) in more than 15% of cases.1 This raised the question of a recurrence of instability and the efficacy of the ACL reconstruction in the prevention of osteoarthritis. Current techniques do not completely reproduce the anatomy and function of the ACL. They address only the anteromedial bundle (AMB) and do not fully reproduce ACL function throughout the range of motion. Current grafts control the anteroposterior stability of a knee near extension but are less efficacious in providing rotatory stability. To improve the stability of the knee and to approximate the complex biomechanical role of the ACL, several authors4-13 have recently proposed the reconstruction of the posterolateral bundle (PLB) in addition to the AM bundle. This article will describe the anatomical and biomechanical rationale for our doublebundle ACL reconstruction technique using hamstring tendons routed through 2 tibial and 2 femoral independent tunnels and report the preliminary clinical results.
Anatomy of the ACL The anatomy of the ACL will be described in detail in another chapter of this publication. Emphasis is put on those charac103
P. Christel et al
104 teristics that appear important to us when 2-bundle reconstruction of the ACL is envisaged. We performed a cadaveric study (unpublished data) with 7 fresh knee specimens that were not affected by arthrosis. The morphometric characteristics of both tibial and femoral insertions of the ACL and its 2 principal bundles, anteromedial (AM) and posterolateral (PL) were measured. The anteroposterior length of the tibial ACL insertion was 17.6 ⫾ 2.1 mm and the mediolateral width was 12.7 ⫾ 2.8 mm. The distance calculated between the centers of the 2 bundles was 9.9 ⫾ 2.11 mm. We noted several elements: ● ● ●
The size of the ACL insertion was proportional to the dimensions of the tibial plateau In some cases, it may be possible that the size of the PL bundle insertion is bigger than that of the AM bundle Because of the “duck foot” shape of the tibial insertion of the ACL,14 the center of a bundle did not coincide with the center of the surface of its bony insertion. This last point is a very important factor to be taken into consideration when placing the tibial guide wire.
Taking into account these dimensions, it is always possible, even in cases of large diameter grafts (eg, 8 mm for the AM bundle and 7 mm for the PL bundle) to pierce 2 tunnels on the tibial site while maintaining a bony bridge of at least 2 mm between them. With regard to the femur, the length of the ACL insertion was 18.3 ⫾ 2.3 mm, and its width was 10.3 ⫾ 2.7 mm. The most distal point of the femoral insertion, corresponding to the distal edge of the PL bundle, was very near to the cartilaginous limit of the lateral condyle, at 2.8 ⫾ 1.5 mm. The most proximal point of the femoral insertion of the ACL was situated at 1.8 ⫾ 1.3 mm from the over-the top point. The distance between the centers of the 2 bundles was 8.2 ⫾ 2.2 mm. The dimensions of the femoral and tibial insertions that we measured corresponded to those already published by Odensten and Gillquist.15 As Harner and coworkers have already shown,16 we found that the surface of the femoral insertion of the ACL was slightly smaller than the tibial insertion. The “duck-foot” effect was less noticeable on the femoral side and it is likely that the center of a bundle coincided with that of its bony insertion. As with the tibia, and even in the case of big grafts, it is always possible to pierce 2 independent tunnels, in the center of each bundle, preserving a bony bridge between them.
Biomechanical Evaluation Numerous articles have reported the distinct role of the 2 ACL bundles. It has been demonstrated that their variation in length is different.17-19 The PL bundle extends more than that AM bundle during flexion of the knee. Sakane and coworkers20 have demonstrated that between 0° and 45° flexion, the PL bundle bears the greatest load, with a maximal at about 15° flexion. At 90° flexion it still bears about 35% of the load. The AM bundle bears maximum strain between 60° and 90° flexion, while its load varies little. It bears 30% of the load of the ACL in extension and 45% in flexion. This is because of
Table 1 Statistical Analysis of the Anterior Tibial Translation According to the ACL Status and Flexion Angle Flexion Angle ACL Status
20°
60°
90°
Cut vs native 1-B vs native 2-B vs native
* * NS
* NS NS
* NS NS
*P < 0.05; 1-B: 1-bundle construct, 2-B: 2-bundle construct.
the quasi-isometric nature of the AM bundle, whereas the PL bundle is more anisometric. The authors performed a cadaver experiment to evaluate control of anterior knee laxity after reconstruction of the ACL comparing double 2-strand AM and PL reconstruction with the classic 4-strand technique.21 We hypothesized that the double-bundle reconstruction would provide better control of anterior laxity in both flexion and extension. Sixteen cadaver knees were randomly assigned to the 2 reconstruction techniques. Anterior tibial translation (ATT) was measured with an arthrometer (Rolimeter™) at maximal manual drawer at 20, 60, and 90° of flexion on the intact knee, after section of the ACL and after arthroscopic reconstruction using either the classical four-strand-one-bundle technique or a double-strand AM and PL technique. An EndoButton CL™ (Smith & Nephew, Andover, MA) was used for the femoral fixation of each bundle. Before the tibial fixation of the bundles, the length variation of each construct was measured between 0 and 90° of flexion under a 50-N tension load. An interference screw was then used for the fixation of each bundle within the tibial tunnel. The extra length of the graft was also stapled on the AM aspect of the tibia. In the single reconstruction group the length of the graft varied by 0.5 ⫾ 0.7 mm. In the 2-bundle group, the length variation was 0.5 ⫾ 0.9 mm for the AM bundle and 3.4 ⫾ 0.5 mm for the PL bundle. The ATT for the 16 knees with an intact ACL was 3.2 ⫾ 1.1, 3.5 ⫾ 1.5, and 2.6 ⫾ 1.1 mm at 20, 60, and 90° of flexion, respectively. After cutting the ACL, ATT significantly increased at all angles: 9.4 ⫾ 3.3, 6.1 ⫾ 2.5, and 6.8 ⫾ 2.9 at 20, 60, and 90° of flexion, respectively. After 1-bundle reconstruction, the ATT decreased by 3.7 ⫾ 0.9, 3.1 ⫾ 1.1, and 2.3 ⫾ 1.6 mm again at 20, 60, and 90° of flexion, respectively. After 2-bundle ACL reconstruction the ATT was 3.4 ⫾ 1.3, 2.6 ⫾ 1.5, and 2.4 ⫾ 1.2 mm at 20, 60, and 90° of flexion respectively. Statistical analysis of the results is listed in Table 1. Compared with the classical one-bundle technique, the 2-bundle reconstruction provided a statistically significant improvement in control of ATT at 20° of flexion. This might be related to the location of the AM tibial tunnel, which is more anterior in the 2-bundle technique compared with the 1-bundle technique. Thus, the AM bundle exhibits a more horizontal orientation with a better control of the ATT close to extension (Fig. 1). Another study was recently performed in collaboration with Amis and Bull of the Biomechanical Engineering De-
Anatomic ACL reconstruction in France
105 attachments, a double-stranded gracilis graft and a doublestranded semitendinosus graft are fashioned, with care being taken to ensure that the length of the final (doubled) grafts will be at least 7 cm. The gracilis graft (future posterolateral bundle) is pulled through an EndoButton with a 15-mm loop, whereas the semitendinosus graft (future anteromedial bundle) is passed through an EndoButton CL with a 20-mm loop, given the longer tunnel for the anteromedial bundle. The grafts are tensioned on a tension board and both strands are sutured together on a 30- to 35-mm long distance at each end using a continuous suture to obtain two bundles made of two tendinous strands each (Fig. 3). The cross-sectional diameter of the grafts is measured with 0.5-mm increment sizers.
Arthroscopic Reconstruction Figure 1 Location of the tibial tunnels in 1- or 2-bundle ACL reconstruction in a cadaver. 1: AM bundle, 2: PL bundle, 3: single tunnel in the 1-bundle technique. The AM tunnel of the 2-bundle technique is more anterior than the single tunnel of the 1-bundle reconstruction
partment at Imperial College, London, UK. This study used Flock of Birds technology.22 In 9 cadaveric knees, anterior tibial translation and rotation were measured in the intact knee, after excision of the ACL, and after ACL reconstruction using a four-strand single-bundle technique versus a twostrand two-bundle technique. One-bundle reconstructions and 2-bundle reconstructions were performed in a random order in the same knees. Thus, after one type of reconstruction, the grafts were removed and the tunnels were filled with a special resin. Then, new tunnels were drilled and the other type of reconstruction technique was performed. Figure 2 shows the anterior tibial translation for a 100-N anterior drawer force combined with a 5-Nm internal rotation force between 0 degree and 90° flexion. After 2-bundle reconstruction, the ATT was identical to that of a knee with intact ACL. The difference in ATT between the 1-bundle group and the 2-bundle group was statistically significant between 25° and 35° flexion. Additional results are currently being analyzed.
Surgical Procedure The following technique is derived from the basic articles published by Franceschi and coworkers10 and Bellier and coworkers.13 The patient is placed supine on the operating table. The tourniquet is placed high up on the thigh to allow the exit of Beath needles from the lateral thigh. The foot rests against a distal support which maintains the knee at 90° of flexion. That way, the knee can be moved freely throughout its full range of motion.
Graft Harvesting The harvesting procedure of the hamstring tendons (gracilis and semitendinosus) is identical to the harvesting procedure for the single-bundle technique. After removing the muscular
An anterolateral portal is created, through which the arthroscope is inserted, and instruments are introduced through an anteromedial portal. Both femoral tunnels are drilled insideout through the AM portal. After the arthroscopic evaluation and treatment of related conditions, the femoral tunnels are first created. The notch and inner aspect of the lateral femoral condyle are prepared to the point where the posterior aspect of the lateral condyle and the origin of the ACL are well visualized (9:00 to 12:00 o’clock position for a right knee, and 12:00- to 3:00-o’clock position for a left knee).
Preparation of the Femoral Tunnel With the knee flexed at least 120°, an endo femoral aimer with a 4-mm offset is introduced through the anteromedial
30
mm 25
20
15
10
5
0 0
30
60
90
-5
Figure 2 Average anterior tibial translation for a 100-N anterior drawer load associated with a 5-Nm internal rotation force couple between 0° and 90° of flexion (〫, native ACL; □, ACL cut; , 1-bundle reconstruction; Œ, 2-bundle reconstruction). After 2-bundle reconstruction, the ATT was identical to that of a knee with intact ACL. The difference in ATT between 1- or 2-bundle was statistically significant between 25° and 35° flexion.
106
P. Christel et al
Figure 4 Femoral tunnel, right knee: For the anteromedial bundle, the guide wire is placed 4 to 5 mm from the posterior border of the lateral femoral condyle, in the standard, 11:00-o’clock position (1: 00-o’clock position for a left knee).
while the posterolateral tunnel does not need to be any wider than 5 to 7 mm. Thus, 2 diverging tunnels are created (Fig. 7).
Figure 3 Grafts are prepared on a tension board. The gracilis graft (G) is pulled through a 15-mm EndoButton CL, whereas the semitendinosus (ST) is passed through a 20-mm EndoButton CL, given the longer tunnel for the anteromedial bundle.
Tibial Tunnels Under arthroscopic control, a specific tibial aimer is now, once again, introduced through the anteromedial portal. As determined from our anatomical measurements, the guide wire for the anteromedial bundle pierces the tibial plateau between the two tibial spines through the center of the AM bundle. The angle of this tunnel is 45 to 50° off the horizontal plane. The entry point on the upper medial tibia is close to the tibial tuberosity. The guide wire for the posterolateral bundle pierces the tibial plateau near the anterolateral tibial spine, approximately 7 mm from the posterior cruciate ligament. The exit point of the guide wire is dependent on the AM guide wire. According to our anatomical measurements, it is located ap-
portal. For the anteromedial bundle, the guide wire is placed 4 mm from the posterior border of the lateral femoral condyle, in the standard 11:00 o’clock position for a right knee (Fig. 4) or 1:00-o’clock position for a left knee. A 4.5-mm cannulated reamer is then introduced on the guide wire, permitting perforation of the lateral cortex of the femur. A specific guide (Fig. 5) is then introduced via the AM portal in the 4.5-mm AM tunnel. It has a divergent direction with the guide-tip introduced into the bone, which directly allows for piercing a second tunnel of 4.5 mm diameter across the condyle, corresponding to the posterolateral bundle placed at the 09:30 position for the right knee (Fig. 6) and at the 2:30 position for the left knee. The anteromedial tunnel is more vertical than its posterolateral counterpart, and a solid bony bridge separates the 2. Eventually, the anteromedial tunnel is reamed with a compacting 6 to 8 mm drill,
Figure 5 Tip of the endofemoral guide for posterolateral tunnel drilling. It is aimed to be introduced in the AM tunnel. Its angulation allows piercing a distal and divergent PL tunnel.
Anatomic ACL reconstruction in France
Figure 6 Femoral tunnel: For the posterolateral bundle, the guide wire is placed at the 2:30 position for the left knee and at the 9:30 position for the right knee. The anteromedial tunnel is more vertical than its posterolateral counterpart, and a solid bony bridge separates the two.
proximately 9 mm posterior to the guide wire of the AM bundle (Fig. 8). The angle of this tunnel is 55 to 60° off the horizontal plane. The entry point on the upper medial tibia is close to the anterior edge of the medial collateral ligament. The 2 tunnels are divergent in all 3 planes, thus assuring a solid bony bridge between them and strong fixation for each bundle. The guide wires are carefully checked for any impingement in the notch, both in flexion and especially in extension. Having confirmed the satisfactory position of our guide wires, the 2 tunnels are then created with compacting routers, beginning with the anteromedial tunnel (from 6 to 8 mm) and followed by the posterolateral tunnel (5 to 7 mm, depending on the thickness of the graft).
107
Figure 8 Endoscopic view of the exit points of the tibial guide wires. The future anteromedial bundle, is situated between the 2 tibial spines, approximately 8 mm anterior to the guide wire of the posterolateral bundle.
Suture loops of different colors are passed through the anteromedial and the posterolateral tunnels using a standard Beath needle to facilitate their identification. First, the posterolateral graft (gracilis) is pulled through the tibial and
femoral tunnels (Fig. 9). Femoral fixation is performed by way of the EndoButton CL. The anteromedial bundle (semitendinosus) is then passed and fixed in a similar manner. It is important to place the knee through a full range of motion before fixation of the grafts, so as to assess separately the length variation of each bundle. The anteromedial bundle is usually isometric, with no appreciable change in length as the knee is flexed and extended through a 90-degree arc. The posterolateral bundle, however, is anisometric and can vary in length by 4 to 6 mm over the same arc of motion. The tibial fixation is performed with 50 N of tension applied to the graft with a spring-loaded dynamometer. The posterolateral bundle is fixed first, with the knee flexed 15°, the knee flexion angle at which the posterolateral bundle is under greatest tension.11 We use an interference screw of 30 to 35 mm in length, which usually is oversized by 1 mm with regard to the tunnel diameter. The anteromedial bundle is then fixed with the knee flexed between 60 and 90°. Finally,
Figure 7 Endoscopic view of the femoral tunnels with threads of different colors ready to pull the graft through.
Figure 9 Endoscopic view of the posterolateral graft (gracilis) alone.
Graft Passage and Fixation
P. Christel et al
108
Paris. Preliminary evaluation was recently available on 135 patients operated on from January 2002 to July 2003 with a minimum one-year follow-up. The preoperative IKDC score was nearly normal in 59 patients (43.5%), and abnormal in 76 patients (56.5%). The average subjective score was 60.3 ⫾ 2.4 (range 58-95). At the last follow-up, 44 patients were ranked as normal (32.7%), 65 as nearly normal (47.8%), 17 as abnormal (13%), and 9 as severely abnormal (6.5%). The average subjective score was 79.5 ⫾ 1.6 (range, 30-100). The improvement was statistically significant (P ⫽ 0.003). Anterior laxity testing using the KT 1000 instrument (side-to-side difference at manual maximum testing) demonstrated significant improvement at P ⫽ 0.001. Several MRI controls were performed. Figure 12 shows a 6-month double-bundle graft where both bundles are clearly identified. Early results are encouraging, but continued prospective and comparative data must be collected to determine the long-term benefits of this more physiologic ACL reconstruction.
Discussion The realization of femoral tunnels by the anteromedial portal permits their anatomical positioning, with a bony bridge ensuring independence of each of the bundles. Femoral drilling through the tibial tunnel does not permit true anatomical positioning.23,24 It is dependent on the tibial tunnel orientation and
Figure 10 (A) Arthroscopic evaluation of the final reconstruction, right knee. (B) For comparison, a native ACL with clear distinct AM and PL bundles is shown.
sutures of both grafts are tied together around a suture post or a staple on the medial aspect of the tibia. The grafts and notch are evaluated arthroscopically to ensure their tension and the absence of impingement between the grafts and the notch (Fig. 10). A postoperative radiograph is shown in Fig. 11. Because we have created a total of four tunnels, we currently place a drain in the knee at the end of the procedure. We recommend the use of a postoperative knee immobilizer for approximately one month, with 50% partial weightbearing. Passive range of motion exercises start immediately after surgery. Nontwisting sports may be resumed at three months postoperatively, and twisting sports at six months postoperatively.
Results Even though this reconstruction technique approximates the functional anatomy of the intact ACL, demonstration of better clinical results is necessary. The first of 2-bundle ACL reconstruction procedures were performed by JP Franceschi in 2000. Since then, more than 500 cases have been operated on by different members of our group in Marseille, Bordeaux and
Figure 11 One-year ML view after 2-bundle ACL reconstruction. Note the 2 EndoButton CL and the 4 tunnels. Tibial fixation has been made with two BioRCI-HA™ interference screws (Smith & Nephew, Andover, MA).
Anatomic ACL reconstruction in France
109 oversized screw of more than 1 mm without enlarging the tunnel’s entry. It is likely that the technique described will evolve in the future as the result of development of better instruments and specific means of fixation. Two-bundle reconstruction of ACL using hamstring tendons is a logical evolution from the 1-bundle technique because of the ease of obtaining 2 individual bundles with the use of these tendons. It is highly likely that other 2-bundle reconstruction techniques based on the use of other grafts will be developed within the next years, eg, bone-hamstring-bone composite grafts26 or allografts, allowing the use of bigger bundles.
Conclusion
Figure 12 Six-month MRI. The knee is in full extension. The two bundles are clearly identified.
exhibits a higher entry point in the notch leading to a sagittally oriented graft. It has been shown by Loh and coworkers25 that the 10-o’clock position more effectively resisted rotatory loads when compared with the 11 o’clock position, while both positions were equally effective in the control of the ATT. The posterolateral tunnel, which is situated in the distal part of the femoral insertion of the ACL at about 9 o’clock, can only be reached and pierced through the AM portal. Nevertheless, positioning of the anteromedial portal must be modified in relation to traditional guide marks. It must be lower and more lateral, at the limit of the medial edge of the patellar tendon to avoid damaging the lateral edge of the medial condyle with the cannulated drills. The length of the anteromedial femoral tunnel is usually between 45 and 50 mm. Use of a 20-mm EndoButton CL ensures a tendon length of 25 to 30 mm within the bone tunnel. In the femoral posterolateral tunnel, with a 15-mm EndoButton CL, the length of bone-tendon contact is 20 to 30 mm. The length of the loop can be modulated depending both on the size of the knee and the length of the intrabony tunnels. The diameters of the tunnels must also correspond to the diameter of the graft as we prefer a “press-fit” bonetendon contact to improve the contact interface. For the tibia, it is necessary to use the longest possible interference screws to increase the resistance of the fixation. For the anteromedial tunnel, it is sometimes necessary to use an oversize 2 mm screw if the cancellous bone is soft. On the other hand, for the posterolateral tunnel which begins on the medial surface of the tibia, the cortical surface of the medial orifice is thick and hard and it is not possible to use an
Considering the complex anatomy of the ACL and the common deficiencies of rotatory control with single-bundle reconstructions, we propose a more physiologic reconstruction that potentially controls both the anteroposterior and the rotatory instability. Specifically, we seek to recreate the 2 bundles of the ACL. We feel that reconstruction of the posterolateral bundle, which is responsible for controlling the internal rotation of the lateral tibial plateau, and the anteromedial bundle, responsible for controlling the anteroposterior stability of the knee, should allow for a more complete reconstruction than the traditional single-bundle procedure. Biomechanical studies favor 2-bundle ACL reconstruction, and preliminary clinical studies encourage us to continue on this path. Nevertheless, quantification of rotatory laxity remains a problem that must be resolved, particularly with regard to the clinical evaluation of patients.
References 1. Bach BR Jr, Tradonsky S, Bojchuk J, et al: Arthroscopically-assisted anterior cruciate ligament reconstruction using patellar tendon autograft. Five- to nine-year follow-up evaluation. Am J Sports Med 26: 20-29, 1998 2. Daniel DM, Stone ML, Dobson BE, et al: Fate of the ACL-injured patient. A prospective outcome study. Am J Sports Med 22:632-644, 1994 3. Nedeff DD, Bach BR Jr: Arthroscopic anterior cruciate ligament reconstruction using patellar tendon autografts: A comprehensive review of contemporary literature. Knee Surg 14:243-258, 2001 4. Rosenberg T, Brown G: Anterior cruciate ligament reconstruction with a quadrupled semitendinosus autograft. Sports Med Arthrosc Rev 5:51-58, 1997 5. Muneta T, Sekiya I, Yagishita K, et al: Two-bundle reconstruction of the anterior cruciate ligament using semitendinosus tendon with Endobuttons: Operative technique and preliminary results. Arthroscopy 15: 618-624, 1999 6. Hara K, Kubo T, Suginoshita T, et al: Reconstruction of the anterior cruciate ligament using a double bundle. Arthroscopy 16:860-864, 2000 7. Pederzini L, Adriani E, Botticella C, et al: Technical note: double tibial tunnel using quadriceps tendon in anterior cruciate ligament reconstruction. Arthroscopy 16:E9, 2000 8. Hamada M, Shino K, Horibe S, et al: Single- versus bi-socket anterior cruciate ligament reconstruction using autogenous multiple-stranded hamstring tendons with EndoButton femoral fixation: A prospective study. Arthroscopy 17:801-807, 2001 9. Mae T, Shino K, Miyama T, et al: Single- versus two-femoral socket anterior cruciate ligament reconstruction technique: Biomechanical analysis using a robotic simulator. Arthroscopy 17:708-716, 2001 10. Franceschi JP, Sbihi A, Champsaur P: Dual arthroscopic reconstruction
P. Christel et al
110
11.
12.
13. 14.
15.
16. 17.
18. 19.
of the anterior cruciate ligament using anteromedial and posterolateral bundles. Rev Chir Orthop 88:691-697, 2002 Yagi M, Wong EK, Kanamori A, et al: Biomechanical analysis of an anatomic anterior cruciate ligament reconstruction. Am J Sports Med 30:660-666, 2002 Marcaccci M, Molgora AP, Zaffagnini S, et al: Anatomic double-bundle anterior cruciate ligament reconstruction with hamstrings. Arthroscopy, 19:540-546, 2003 Bellier G, Christel P, Colombet P, et al: Double stranded hamstring graft for anterior cruciate ligament reconstruction. Arthroscopy, 20:890-894, 2004 Amis AA, Jakob RP: Anterior cruciate ligament graft positioning, tensioning and twisting. Knee Surg Sports Traumatol Arthrosc 6:S2-S12, 1998 (suppl) Odensten M, Gillquist J: Functional anatomy of the anterior cruciate ligament and a rationale for reconstruction. J Bone Joint Surg Am 67: 257-262, 1985 Harner CD, Baek GH, Vogrin TM, et al: Quantitative analysis of human cruciate ligament insertions. Arthroscopy 15:741-749, 1999 Dorlot JM, Christel P, Witvoet J, et al: Displacement of cruciate ligament insertions during flexion of the normal knee. Rev Chir Ortop 70:50-53, 1984 (suppl 2) Norwood LA, Cross MJ: Anterior cruciate ligament: functional anatomy of its bundles in rotatory instabilities. Am J Sports Med 7:23-26, 1979 Hollis JM, Takai S, Adams DJ, et al: The effects of knee motion and
20.
21.
22.
23.
24.
25.
26.
external loading on the length of the anterior cruciate ligament (ACL): A kinematic study. J Biomech Eng 113:208-214, 1991 Sakane M, Fox RJ, Woo S L-Y, et al: In situ forces in the anterior cruciate ligament and its bundles in response to anterior tibial loads. J Othop Res 15:285-293, 1997 Sbihi A, Franceschi JP, Christel P, et al: Anterior cruciate ligament reconstruction: Biomechanical comparison on cadaver specimens using a single or double hamstring technique. Rev Chir Orthop 20:890-894, 2004 Bull AM, Earnshaw PH, Smith A, et al: Intraoperative measurement of knee kinematics in reconstruction of the anterior cruciate ligament. J Bone Joint Surg Br 84:1075-1081, 2002 Giron F, Buzzi R, Aglietti P: Femoral tunnel position in anterior cruciate ligament reconstruction using three techniques. A cadaver study. Arthroscopy 15:750-756, 1999 Arnold MP, Kooloos J, van Kampen A: Single-incision technique misses the anatomical femoral anterior cruciate ligament insertion: a cadaver study. Knee Surg Sports Traumatol Arthrosc 9:194-199, 2001 Loh JC, Fukuda Y, Tsuda E, et al: Knee stability and graft function following anterior cruciate ligament reconstruction: Comparison between 11 o’clock and 10 o’clock femoral tunnel placement. Arthroscopy 19:297-304, 2003 Takeuchi R, Sazito T, Mituhashi S, et al: Double-bundle anatomic anterior cruciate ligament reconstruction using bone-hamstring-bone composite graft. Arthroscopy 18:550-555, 2002
A
s a result of better understanding of its anatomy and biomechanical function, reconstruction of the anterior cruciate ligament (ACL) has been increasingly successful during the past 15 years. The use of arthroscopy permits precise positioning of the graft. In addition, the use of strong grafts and fixation systems has resulted in reliable functional results for this procedure. Nevertheless, a review of the literature shows that simple ACL reconstruction by bone-patellar-tendon-bone graft results in insufficient long-term outcomes (Grades C and D, International Documentation Knee Committee [IKDC] system) in 11% to 30% of the cases1-3 and, more importantly, in the persistence of pivot shift
*Department of Orthopaedic Surgery, Institut de l’Appareil Locomoteur Nollet, Paris, France. †Hôpital Privé Paul d’Egine, Champigny-sur-Marne, France. ‡Service du Professeur Curvale, Hôpital de la Conception, Marseille, France. §CCOS Mérignac, France. 储Cabinet Goethe, Paris, France. Address reprint requests to Pascal Christel, MD, PhD, Institut de l’Appareil Locomoteur Nollet, 23, rue Brochant, 75017 Paris, France. E-mail: [email protected]
1048-6666/05/$-see front matter © 2005 Elsevier Inc. All rights reserved. doi:10.1053/j.oto.2004.11.008
(Grade B, IKDC system) in more than 15% of cases.1 This raised the question of a recurrence of instability and the efficacy of the ACL reconstruction in the prevention of osteoarthritis. Current techniques do not completely reproduce the anatomy and function of the ACL. They address only the anteromedial bundle (AMB) and do not fully reproduce ACL function throughout the range of motion. Current grafts control the anteroposterior stability of a knee near extension but are less efficacious in providing rotatory stability. To improve the stability of the knee and to approximate the complex biomechanical role of the ACL, several authors4-13 have recently proposed the reconstruction of the posterolateral bundle (PLB) in addition to the AM bundle. This article will describe the anatomical and biomechanical rationale for our doublebundle ACL reconstruction technique using hamstring tendons routed through 2 tibial and 2 femoral independent tunnels and report the preliminary clinical results.
Anatomy of the ACL The anatomy of the ACL will be described in detail in another chapter of this publication. Emphasis is put on those charac103
P. Christel et al
104 teristics that appear important to us when 2-bundle reconstruction of the ACL is envisaged. We performed a cadaveric study (unpublished data) with 7 fresh knee specimens that were not affected by arthrosis. The morphometric characteristics of both tibial and femoral insertions of the ACL and its 2 principal bundles, anteromedial (AM) and posterolateral (PL) were measured. The anteroposterior length of the tibial ACL insertion was 17.6 ⫾ 2.1 mm and the mediolateral width was 12.7 ⫾ 2.8 mm. The distance calculated between the centers of the 2 bundles was 9.9 ⫾ 2.11 mm. We noted several elements: ● ● ●
The size of the ACL insertion was proportional to the dimensions of the tibial plateau In some cases, it may be possible that the size of the PL bundle insertion is bigger than that of the AM bundle Because of the “duck foot” shape of the tibial insertion of the ACL,14 the center of a bundle did not coincide with the center of the surface of its bony insertion. This last point is a very important factor to be taken into consideration when placing the tibial guide wire.
Taking into account these dimensions, it is always possible, even in cases of large diameter grafts (eg, 8 mm for the AM bundle and 7 mm for the PL bundle) to pierce 2 tunnels on the tibial site while maintaining a bony bridge of at least 2 mm between them. With regard to the femur, the length of the ACL insertion was 18.3 ⫾ 2.3 mm, and its width was 10.3 ⫾ 2.7 mm. The most distal point of the femoral insertion, corresponding to the distal edge of the PL bundle, was very near to the cartilaginous limit of the lateral condyle, at 2.8 ⫾ 1.5 mm. The most proximal point of the femoral insertion of the ACL was situated at 1.8 ⫾ 1.3 mm from the over-the top point. The distance between the centers of the 2 bundles was 8.2 ⫾ 2.2 mm. The dimensions of the femoral and tibial insertions that we measured corresponded to those already published by Odensten and Gillquist.15 As Harner and coworkers have already shown,16 we found that the surface of the femoral insertion of the ACL was slightly smaller than the tibial insertion. The “duck-foot” effect was less noticeable on the femoral side and it is likely that the center of a bundle coincided with that of its bony insertion. As with the tibia, and even in the case of big grafts, it is always possible to pierce 2 independent tunnels, in the center of each bundle, preserving a bony bridge between them.
Biomechanical Evaluation Numerous articles have reported the distinct role of the 2 ACL bundles. It has been demonstrated that their variation in length is different.17-19 The PL bundle extends more than that AM bundle during flexion of the knee. Sakane and coworkers20 have demonstrated that between 0° and 45° flexion, the PL bundle bears the greatest load, with a maximal at about 15° flexion. At 90° flexion it still bears about 35% of the load. The AM bundle bears maximum strain between 60° and 90° flexion, while its load varies little. It bears 30% of the load of the ACL in extension and 45% in flexion. This is because of
Table 1 Statistical Analysis of the Anterior Tibial Translation According to the ACL Status and Flexion Angle Flexion Angle ACL Status
20°
60°
90°
Cut vs native 1-B vs native 2-B vs native
* * NS
* NS NS
* NS NS
*P < 0.05; 1-B: 1-bundle construct, 2-B: 2-bundle construct.
the quasi-isometric nature of the AM bundle, whereas the PL bundle is more anisometric. The authors performed a cadaver experiment to evaluate control of anterior knee laxity after reconstruction of the ACL comparing double 2-strand AM and PL reconstruction with the classic 4-strand technique.21 We hypothesized that the double-bundle reconstruction would provide better control of anterior laxity in both flexion and extension. Sixteen cadaver knees were randomly assigned to the 2 reconstruction techniques. Anterior tibial translation (ATT) was measured with an arthrometer (Rolimeter™) at maximal manual drawer at 20, 60, and 90° of flexion on the intact knee, after section of the ACL and after arthroscopic reconstruction using either the classical four-strand-one-bundle technique or a double-strand AM and PL technique. An EndoButton CL™ (Smith & Nephew, Andover, MA) was used for the femoral fixation of each bundle. Before the tibial fixation of the bundles, the length variation of each construct was measured between 0 and 90° of flexion under a 50-N tension load. An interference screw was then used for the fixation of each bundle within the tibial tunnel. The extra length of the graft was also stapled on the AM aspect of the tibia. In the single reconstruction group the length of the graft varied by 0.5 ⫾ 0.7 mm. In the 2-bundle group, the length variation was 0.5 ⫾ 0.9 mm for the AM bundle and 3.4 ⫾ 0.5 mm for the PL bundle. The ATT for the 16 knees with an intact ACL was 3.2 ⫾ 1.1, 3.5 ⫾ 1.5, and 2.6 ⫾ 1.1 mm at 20, 60, and 90° of flexion, respectively. After cutting the ACL, ATT significantly increased at all angles: 9.4 ⫾ 3.3, 6.1 ⫾ 2.5, and 6.8 ⫾ 2.9 at 20, 60, and 90° of flexion, respectively. After 1-bundle reconstruction, the ATT decreased by 3.7 ⫾ 0.9, 3.1 ⫾ 1.1, and 2.3 ⫾ 1.6 mm again at 20, 60, and 90° of flexion, respectively. After 2-bundle ACL reconstruction the ATT was 3.4 ⫾ 1.3, 2.6 ⫾ 1.5, and 2.4 ⫾ 1.2 mm at 20, 60, and 90° of flexion respectively. Statistical analysis of the results is listed in Table 1. Compared with the classical one-bundle technique, the 2-bundle reconstruction provided a statistically significant improvement in control of ATT at 20° of flexion. This might be related to the location of the AM tibial tunnel, which is more anterior in the 2-bundle technique compared with the 1-bundle technique. Thus, the AM bundle exhibits a more horizontal orientation with a better control of the ATT close to extension (Fig. 1). Another study was recently performed in collaboration with Amis and Bull of the Biomechanical Engineering De-
Anatomic ACL reconstruction in France
105 attachments, a double-stranded gracilis graft and a doublestranded semitendinosus graft are fashioned, with care being taken to ensure that the length of the final (doubled) grafts will be at least 7 cm. The gracilis graft (future posterolateral bundle) is pulled through an EndoButton with a 15-mm loop, whereas the semitendinosus graft (future anteromedial bundle) is passed through an EndoButton CL with a 20-mm loop, given the longer tunnel for the anteromedial bundle. The grafts are tensioned on a tension board and both strands are sutured together on a 30- to 35-mm long distance at each end using a continuous suture to obtain two bundles made of two tendinous strands each (Fig. 3). The cross-sectional diameter of the grafts is measured with 0.5-mm increment sizers.
Arthroscopic Reconstruction Figure 1 Location of the tibial tunnels in 1- or 2-bundle ACL reconstruction in a cadaver. 1: AM bundle, 2: PL bundle, 3: single tunnel in the 1-bundle technique. The AM tunnel of the 2-bundle technique is more anterior than the single tunnel of the 1-bundle reconstruction
partment at Imperial College, London, UK. This study used Flock of Birds technology.22 In 9 cadaveric knees, anterior tibial translation and rotation were measured in the intact knee, after excision of the ACL, and after ACL reconstruction using a four-strand single-bundle technique versus a twostrand two-bundle technique. One-bundle reconstructions and 2-bundle reconstructions were performed in a random order in the same knees. Thus, after one type of reconstruction, the grafts were removed and the tunnels were filled with a special resin. Then, new tunnels were drilled and the other type of reconstruction technique was performed. Figure 2 shows the anterior tibial translation for a 100-N anterior drawer force combined with a 5-Nm internal rotation force between 0 degree and 90° flexion. After 2-bundle reconstruction, the ATT was identical to that of a knee with intact ACL. The difference in ATT between the 1-bundle group and the 2-bundle group was statistically significant between 25° and 35° flexion. Additional results are currently being analyzed.
Surgical Procedure The following technique is derived from the basic articles published by Franceschi and coworkers10 and Bellier and coworkers.13 The patient is placed supine on the operating table. The tourniquet is placed high up on the thigh to allow the exit of Beath needles from the lateral thigh. The foot rests against a distal support which maintains the knee at 90° of flexion. That way, the knee can be moved freely throughout its full range of motion.
Graft Harvesting The harvesting procedure of the hamstring tendons (gracilis and semitendinosus) is identical to the harvesting procedure for the single-bundle technique. After removing the muscular
An anterolateral portal is created, through which the arthroscope is inserted, and instruments are introduced through an anteromedial portal. Both femoral tunnels are drilled insideout through the AM portal. After the arthroscopic evaluation and treatment of related conditions, the femoral tunnels are first created. The notch and inner aspect of the lateral femoral condyle are prepared to the point where the posterior aspect of the lateral condyle and the origin of the ACL are well visualized (9:00 to 12:00 o’clock position for a right knee, and 12:00- to 3:00-o’clock position for a left knee).
Preparation of the Femoral Tunnel With the knee flexed at least 120°, an endo femoral aimer with a 4-mm offset is introduced through the anteromedial
30
mm 25
20
15
10
5
0 0
30
60
90
-5
Figure 2 Average anterior tibial translation for a 100-N anterior drawer load associated with a 5-Nm internal rotation force couple between 0° and 90° of flexion (〫, native ACL; □, ACL cut; , 1-bundle reconstruction; Œ, 2-bundle reconstruction). After 2-bundle reconstruction, the ATT was identical to that of a knee with intact ACL. The difference in ATT between 1- or 2-bundle was statistically significant between 25° and 35° flexion.
106
P. Christel et al
Figure 4 Femoral tunnel, right knee: For the anteromedial bundle, the guide wire is placed 4 to 5 mm from the posterior border of the lateral femoral condyle, in the standard, 11:00-o’clock position (1: 00-o’clock position for a left knee).
while the posterolateral tunnel does not need to be any wider than 5 to 7 mm. Thus, 2 diverging tunnels are created (Fig. 7).
Figure 3 Grafts are prepared on a tension board. The gracilis graft (G) is pulled through a 15-mm EndoButton CL, whereas the semitendinosus (ST) is passed through a 20-mm EndoButton CL, given the longer tunnel for the anteromedial bundle.
Tibial Tunnels Under arthroscopic control, a specific tibial aimer is now, once again, introduced through the anteromedial portal. As determined from our anatomical measurements, the guide wire for the anteromedial bundle pierces the tibial plateau between the two tibial spines through the center of the AM bundle. The angle of this tunnel is 45 to 50° off the horizontal plane. The entry point on the upper medial tibia is close to the tibial tuberosity. The guide wire for the posterolateral bundle pierces the tibial plateau near the anterolateral tibial spine, approximately 7 mm from the posterior cruciate ligament. The exit point of the guide wire is dependent on the AM guide wire. According to our anatomical measurements, it is located ap-
portal. For the anteromedial bundle, the guide wire is placed 4 mm from the posterior border of the lateral femoral condyle, in the standard 11:00 o’clock position for a right knee (Fig. 4) or 1:00-o’clock position for a left knee. A 4.5-mm cannulated reamer is then introduced on the guide wire, permitting perforation of the lateral cortex of the femur. A specific guide (Fig. 5) is then introduced via the AM portal in the 4.5-mm AM tunnel. It has a divergent direction with the guide-tip introduced into the bone, which directly allows for piercing a second tunnel of 4.5 mm diameter across the condyle, corresponding to the posterolateral bundle placed at the 09:30 position for the right knee (Fig. 6) and at the 2:30 position for the left knee. The anteromedial tunnel is more vertical than its posterolateral counterpart, and a solid bony bridge separates the 2. Eventually, the anteromedial tunnel is reamed with a compacting 6 to 8 mm drill,
Figure 5 Tip of the endofemoral guide for posterolateral tunnel drilling. It is aimed to be introduced in the AM tunnel. Its angulation allows piercing a distal and divergent PL tunnel.
Anatomic ACL reconstruction in France
Figure 6 Femoral tunnel: For the posterolateral bundle, the guide wire is placed at the 2:30 position for the left knee and at the 9:30 position for the right knee. The anteromedial tunnel is more vertical than its posterolateral counterpart, and a solid bony bridge separates the two.
proximately 9 mm posterior to the guide wire of the AM bundle (Fig. 8). The angle of this tunnel is 55 to 60° off the horizontal plane. The entry point on the upper medial tibia is close to the anterior edge of the medial collateral ligament. The 2 tunnels are divergent in all 3 planes, thus assuring a solid bony bridge between them and strong fixation for each bundle. The guide wires are carefully checked for any impingement in the notch, both in flexion and especially in extension. Having confirmed the satisfactory position of our guide wires, the 2 tunnels are then created with compacting routers, beginning with the anteromedial tunnel (from 6 to 8 mm) and followed by the posterolateral tunnel (5 to 7 mm, depending on the thickness of the graft).
107
Figure 8 Endoscopic view of the exit points of the tibial guide wires. The future anteromedial bundle, is situated between the 2 tibial spines, approximately 8 mm anterior to the guide wire of the posterolateral bundle.
Suture loops of different colors are passed through the anteromedial and the posterolateral tunnels using a standard Beath needle to facilitate their identification. First, the posterolateral graft (gracilis) is pulled through the tibial and
femoral tunnels (Fig. 9). Femoral fixation is performed by way of the EndoButton CL. The anteromedial bundle (semitendinosus) is then passed and fixed in a similar manner. It is important to place the knee through a full range of motion before fixation of the grafts, so as to assess separately the length variation of each bundle. The anteromedial bundle is usually isometric, with no appreciable change in length as the knee is flexed and extended through a 90-degree arc. The posterolateral bundle, however, is anisometric and can vary in length by 4 to 6 mm over the same arc of motion. The tibial fixation is performed with 50 N of tension applied to the graft with a spring-loaded dynamometer. The posterolateral bundle is fixed first, with the knee flexed 15°, the knee flexion angle at which the posterolateral bundle is under greatest tension.11 We use an interference screw of 30 to 35 mm in length, which usually is oversized by 1 mm with regard to the tunnel diameter. The anteromedial bundle is then fixed with the knee flexed between 60 and 90°. Finally,
Figure 7 Endoscopic view of the femoral tunnels with threads of different colors ready to pull the graft through.
Figure 9 Endoscopic view of the posterolateral graft (gracilis) alone.
Graft Passage and Fixation
P. Christel et al
108
Paris. Preliminary evaluation was recently available on 135 patients operated on from January 2002 to July 2003 with a minimum one-year follow-up. The preoperative IKDC score was nearly normal in 59 patients (43.5%), and abnormal in 76 patients (56.5%). The average subjective score was 60.3 ⫾ 2.4 (range 58-95). At the last follow-up, 44 patients were ranked as normal (32.7%), 65 as nearly normal (47.8%), 17 as abnormal (13%), and 9 as severely abnormal (6.5%). The average subjective score was 79.5 ⫾ 1.6 (range, 30-100). The improvement was statistically significant (P ⫽ 0.003). Anterior laxity testing using the KT 1000 instrument (side-to-side difference at manual maximum testing) demonstrated significant improvement at P ⫽ 0.001. Several MRI controls were performed. Figure 12 shows a 6-month double-bundle graft where both bundles are clearly identified. Early results are encouraging, but continued prospective and comparative data must be collected to determine the long-term benefits of this more physiologic ACL reconstruction.
Discussion The realization of femoral tunnels by the anteromedial portal permits their anatomical positioning, with a bony bridge ensuring independence of each of the bundles. Femoral drilling through the tibial tunnel does not permit true anatomical positioning.23,24 It is dependent on the tibial tunnel orientation and
Figure 10 (A) Arthroscopic evaluation of the final reconstruction, right knee. (B) For comparison, a native ACL with clear distinct AM and PL bundles is shown.
sutures of both grafts are tied together around a suture post or a staple on the medial aspect of the tibia. The grafts and notch are evaluated arthroscopically to ensure their tension and the absence of impingement between the grafts and the notch (Fig. 10). A postoperative radiograph is shown in Fig. 11. Because we have created a total of four tunnels, we currently place a drain in the knee at the end of the procedure. We recommend the use of a postoperative knee immobilizer for approximately one month, with 50% partial weightbearing. Passive range of motion exercises start immediately after surgery. Nontwisting sports may be resumed at three months postoperatively, and twisting sports at six months postoperatively.
Results Even though this reconstruction technique approximates the functional anatomy of the intact ACL, demonstration of better clinical results is necessary. The first of 2-bundle ACL reconstruction procedures were performed by JP Franceschi in 2000. Since then, more than 500 cases have been operated on by different members of our group in Marseille, Bordeaux and
Figure 11 One-year ML view after 2-bundle ACL reconstruction. Note the 2 EndoButton CL and the 4 tunnels. Tibial fixation has been made with two BioRCI-HA™ interference screws (Smith & Nephew, Andover, MA).
Anatomic ACL reconstruction in France
109 oversized screw of more than 1 mm without enlarging the tunnel’s entry. It is likely that the technique described will evolve in the future as the result of development of better instruments and specific means of fixation. Two-bundle reconstruction of ACL using hamstring tendons is a logical evolution from the 1-bundle technique because of the ease of obtaining 2 individual bundles with the use of these tendons. It is highly likely that other 2-bundle reconstruction techniques based on the use of other grafts will be developed within the next years, eg, bone-hamstring-bone composite grafts26 or allografts, allowing the use of bigger bundles.
Conclusion
Figure 12 Six-month MRI. The knee is in full extension. The two bundles are clearly identified.
exhibits a higher entry point in the notch leading to a sagittally oriented graft. It has been shown by Loh and coworkers25 that the 10-o’clock position more effectively resisted rotatory loads when compared with the 11 o’clock position, while both positions were equally effective in the control of the ATT. The posterolateral tunnel, which is situated in the distal part of the femoral insertion of the ACL at about 9 o’clock, can only be reached and pierced through the AM portal. Nevertheless, positioning of the anteromedial portal must be modified in relation to traditional guide marks. It must be lower and more lateral, at the limit of the medial edge of the patellar tendon to avoid damaging the lateral edge of the medial condyle with the cannulated drills. The length of the anteromedial femoral tunnel is usually between 45 and 50 mm. Use of a 20-mm EndoButton CL ensures a tendon length of 25 to 30 mm within the bone tunnel. In the femoral posterolateral tunnel, with a 15-mm EndoButton CL, the length of bone-tendon contact is 20 to 30 mm. The length of the loop can be modulated depending both on the size of the knee and the length of the intrabony tunnels. The diameters of the tunnels must also correspond to the diameter of the graft as we prefer a “press-fit” bonetendon contact to improve the contact interface. For the tibia, it is necessary to use the longest possible interference screws to increase the resistance of the fixation. For the anteromedial tunnel, it is sometimes necessary to use an oversize 2 mm screw if the cancellous bone is soft. On the other hand, for the posterolateral tunnel which begins on the medial surface of the tibia, the cortical surface of the medial orifice is thick and hard and it is not possible to use an
Considering the complex anatomy of the ACL and the common deficiencies of rotatory control with single-bundle reconstructions, we propose a more physiologic reconstruction that potentially controls both the anteroposterior and the rotatory instability. Specifically, we seek to recreate the 2 bundles of the ACL. We feel that reconstruction of the posterolateral bundle, which is responsible for controlling the internal rotation of the lateral tibial plateau, and the anteromedial bundle, responsible for controlling the anteroposterior stability of the knee, should allow for a more complete reconstruction than the traditional single-bundle procedure. Biomechanical studies favor 2-bundle ACL reconstruction, and preliminary clinical studies encourage us to continue on this path. Nevertheless, quantification of rotatory laxity remains a problem that must be resolved, particularly with regard to the clinical evaluation of patients.
References 1. Bach BR Jr, Tradonsky S, Bojchuk J, et al: Arthroscopically-assisted anterior cruciate ligament reconstruction using patellar tendon autograft. Five- to nine-year follow-up evaluation. Am J Sports Med 26: 20-29, 1998 2. Daniel DM, Stone ML, Dobson BE, et al: Fate of the ACL-injured patient. A prospective outcome study. Am J Sports Med 22:632-644, 1994 3. Nedeff DD, Bach BR Jr: Arthroscopic anterior cruciate ligament reconstruction using patellar tendon autografts: A comprehensive review of contemporary literature. Knee Surg 14:243-258, 2001 4. Rosenberg T, Brown G: Anterior cruciate ligament reconstruction with a quadrupled semitendinosus autograft. Sports Med Arthrosc Rev 5:51-58, 1997 5. Muneta T, Sekiya I, Yagishita K, et al: Two-bundle reconstruction of the anterior cruciate ligament using semitendinosus tendon with Endobuttons: Operative technique and preliminary results. Arthroscopy 15: 618-624, 1999 6. Hara K, Kubo T, Suginoshita T, et al: Reconstruction of the anterior cruciate ligament using a double bundle. Arthroscopy 16:860-864, 2000 7. Pederzini L, Adriani E, Botticella C, et al: Technical note: double tibial tunnel using quadriceps tendon in anterior cruciate ligament reconstruction. Arthroscopy 16:E9, 2000 8. Hamada M, Shino K, Horibe S, et al: Single- versus bi-socket anterior cruciate ligament reconstruction using autogenous multiple-stranded hamstring tendons with EndoButton femoral fixation: A prospective study. Arthroscopy 17:801-807, 2001 9. Mae T, Shino K, Miyama T, et al: Single- versus two-femoral socket anterior cruciate ligament reconstruction technique: Biomechanical analysis using a robotic simulator. Arthroscopy 17:708-716, 2001 10. Franceschi JP, Sbihi A, Champsaur P: Dual arthroscopic reconstruction
P. Christel et al
110
11.
12.
13. 14.
15.
16. 17.
18. 19.
of the anterior cruciate ligament using anteromedial and posterolateral bundles. Rev Chir Orthop 88:691-697, 2002 Yagi M, Wong EK, Kanamori A, et al: Biomechanical analysis of an anatomic anterior cruciate ligament reconstruction. Am J Sports Med 30:660-666, 2002 Marcaccci M, Molgora AP, Zaffagnini S, et al: Anatomic double-bundle anterior cruciate ligament reconstruction with hamstrings. Arthroscopy, 19:540-546, 2003 Bellier G, Christel P, Colombet P, et al: Double stranded hamstring graft for anterior cruciate ligament reconstruction. Arthroscopy, 20:890-894, 2004 Amis AA, Jakob RP: Anterior cruciate ligament graft positioning, tensioning and twisting. Knee Surg Sports Traumatol Arthrosc 6:S2-S12, 1998 (suppl) Odensten M, Gillquist J: Functional anatomy of the anterior cruciate ligament and a rationale for reconstruction. J Bone Joint Surg Am 67: 257-262, 1985 Harner CD, Baek GH, Vogrin TM, et al: Quantitative analysis of human cruciate ligament insertions. Arthroscopy 15:741-749, 1999 Dorlot JM, Christel P, Witvoet J, et al: Displacement of cruciate ligament insertions during flexion of the normal knee. Rev Chir Ortop 70:50-53, 1984 (suppl 2) Norwood LA, Cross MJ: Anterior cruciate ligament: functional anatomy of its bundles in rotatory instabilities. Am J Sports Med 7:23-26, 1979 Hollis JM, Takai S, Adams DJ, et al: The effects of knee motion and
20.
21.
22.
23.
24.
25.
26.
external loading on the length of the anterior cruciate ligament (ACL): A kinematic study. J Biomech Eng 113:208-214, 1991 Sakane M, Fox RJ, Woo S L-Y, et al: In situ forces in the anterior cruciate ligament and its bundles in response to anterior tibial loads. J Othop Res 15:285-293, 1997 Sbihi A, Franceschi JP, Christel P, et al: Anterior cruciate ligament reconstruction: Biomechanical comparison on cadaver specimens using a single or double hamstring technique. Rev Chir Orthop 20:890-894, 2004 Bull AM, Earnshaw PH, Smith A, et al: Intraoperative measurement of knee kinematics in reconstruction of the anterior cruciate ligament. J Bone Joint Surg Br 84:1075-1081, 2002 Giron F, Buzzi R, Aglietti P: Femoral tunnel position in anterior cruciate ligament reconstruction using three techniques. A cadaver study. Arthroscopy 15:750-756, 1999 Arnold MP, Kooloos J, van Kampen A: Single-incision technique misses the anatomical femoral anterior cruciate ligament insertion: a cadaver study. Knee Surg Sports Traumatol Arthrosc 9:194-199, 2001 Loh JC, Fukuda Y, Tsuda E, et al: Knee stability and graft function following anterior cruciate ligament reconstruction: Comparison between 11 o’clock and 10 o’clock femoral tunnel placement. Arthroscopy 19:297-304, 2003 Takeuchi R, Sazito T, Mituhashi S, et al: Double-bundle anatomic anterior cruciate ligament reconstruction using bone-hamstring-bone composite graft. Arthroscopy 18:550-555, 2002