Printer Friendly

Bone-patellar tendon-bone graft preparation technique to increase cross-sectional area of the graft in anterior cruciate ligament reconstruction/ Tehnika obrade kost-ligament casice-kost kalema za povecanje povrsine poprecnog preseka kalema kod rekonstrukcije prednjeg ukrstenog ligamenta kolena.


Patellar tendon autografts are used daily by orthopedic surgeons for anterior cruciate ligament (ACL) reconstruction because they are known to give good and easily reproducible clinical results. The first surgeon who used a part of patellar ligament for ACL replacement was Langworthy in 1930s [1]. Thirty years later, Jones [2] and Bruckner [3] refined the initial technique by using the central third of the patellar tendon. Following Franke's [4] publication, bone-patellar tendon-bone (BTB) became one of the most popular graft sources and gained further popularity both in Europe and the United States through the work of Eriksson [5] and Clancy [6].

The use of BTB graft is associated with excellent clinical results in 80-90% of cases, as well as some complications of the knee extensor mechanism, including BTB harvest site morbidity [7] and disruption of the knee extensor apparatus [8]. Bone-patellar tendon-bone graft ensures strong initial graft fixation using interference screws, allowing direct bone-bone healing and consecutive bony integration at the fixation points of the reconstruction [7]. The main disadvantage of BTB is a graft-tunnel mismatch [9] due to a smaller cross-section area and incomplete filling of the tunnel compared to hamstring tendon graft [10, 11].

Not much has changed in the way the BTB graft is prepared before implantation. Pujil et al. [12] described arthroscopic double-bundle ACL reconstruction technique using a rectangular patellar bone block, a double stranded patellar tendon, and a double tibial bone block. By simulating anatomical ACL reconstruction, Shino et al. [13] and Herbort et al. [14] tried to improve the BTB SB technique, creating a rectangular tunnel and bony part of the graft, neglecting the importance of the cross-sectional area of the classic BTB graft, with a width of 10 mm and the thickness of 3-5 mm, which ultimately depends on the individual patient's characteristics [15-17].

The aim of this study was to present the modified BTB graft preparation technique. We hypothesized that modified BTB graft preparation technique would increase the cross-sectional area of the graft, thus getting closer to the characteristics of the native ACL and/or hamstring tendon graft.

Material and Methods

The procedure of the study was approved by the Local Human Research Ethical Committee. A prospective study, conducted from July 1 to December 31, 2013, included 93 male patients of the average age 26 (15-44) in whom measurements of the patellar tendon and BTB graft were performed during the anterior cruciate ligament reconstruction. Only men were included in the study due to a small number of women operated in that period. The knee was approached through a vertical skin incision made from the middle of the patella to the inferior portion of the tibial tubercle, with the knee flexed. The skin flaps were created and the incision was sharply carried down through the transverse fibres of the paratenon. The paratenon was incised at its midpoint to expose the entire width of the patellar tendon. Next, while maintaining the tendon in a stretched position by flexing the knee, it was incised first on one side of the graft followed by the other side, obtaining 12-14 mm wide patellar tendon. Then, a chisel was used to create the tibial bone plug, approximately 25 mm long and 10mm wide, by scoring the tibial cortex and removing an equilateral triangle of bone with the saw. An osteotome was used to lift the tibial bone plug carefully from its bed onto a lap pad. The patellar tendon with a tibial bone plug was lifted up and cleaned off the remaining soft tissue attachments with the scissors. Using an oscillating saw, a patellar plug of trapezoidal shape, 25 mm long and 10 mm wide, was created and gently removed. The tendinous part of the BTB graft was measured (its width and thickness) and prepared on a side table by an assistant (Figure 1). The graft was then placed on the holder with a handle in a way which allowed sewing the edges of the patellar tendon in the shape of a tube (Figure 2). The diameter of the graft was determined by passing the folded graft through the sizing cylinders with incremental size changes of 1 mm. The circumference of the central part of the BTB graft was manually measured using a suture tightened around the graft. The suture was then cut and its length was measured in mm [14]. The diameters of the circle and the cross-sectional areas were then calculated using a geometrical calculation (O = 2r[pi] and P = [r.sup.2][pi]) (Figure 3).

The standard anterolateral portal was used as a viewing portal and the anteromedial one as a working portal. The ACL stump was debrided. The femoral tunnel was created through the anteromedial portal to avoid excess fluid loss. The knee was placed at 110-120 degrees of flexion. The femoral guide with an appropriate offset was introduced into the joint through the anteromedial portal. With the help of a femoral guide, a drill-wire was placed into the centre of the anatomic ACL insertion which was then overdrilled with a 10-mm diameter reamer. A suture was retrieved after the guide pin had been drilled into the joint. Afterwards, a cannulated reamer with an equal diameter to the graft created the tibial tunnel. A grasper was then placed through the tibial tunnel to retrieve the suture. Then the graft was passed through the tibia into the femoral socket, and once the graft was properly positioned in the tunnel, it was fixed with round cannulated interference screws (RCI). Firm traction was applied to the tibial bone block while putting the knee through the full range of knee motion in order to pretense the graft and make sure that there is no impingement in full extension. The graft was then tensioned using 80 N force and the screws were additionally tightened if needed. Lachman test was used to check the knee stability. A drain was placed in the knee and the operative wound was closed in the usual fashion.


The width and the thickness of patellar tendon was 33 mm (28-43) and 4.05 mm (3-5), respectively. The width of the taken patellar tendon was 13.62 mm (12-14). After the preparation of the BTB grafts (Table 1), the following measures were recorded: the circumference of 30 mm, the diameter of 9.55, and the cross-sectional area of 71.59 [mm.sup.2] in 9 patients; the circumference of 31 mm, the diameter of 9.87 mm, and the cross-sectional area of 76.50 [mm.sup.2] in 15 patients, and the circumference of 32 mm, the diameter of 10.19 mm, and the cross-sectional area of 81.51 [mm.sup.2] in 69 patients.


The patellar tendon is the most distal part of the extensor mechanism which connects the inferior pole of the patella and the tibial tubercle. Technically, it is a ligament (connecting a bone to a bone), but it has often been referred to as a tendon because the patella is a sesamoid bone. The average length of the patellar tendon is 40-53 mm [15, 16, 18, 19]. The patellar tendon is wider proximally than distally because the fascicles tend to converge toward the midline [20]. Yoo et al. [15] measured the width of the proximal and distal part of the tendon and they were 30 mm and 24 mm, respectively. In our study, the mean patellar tendon width measured in the middle of the tendon was 33 mm (28-43 mm). Regarding the thickness of the patellar tendon, it has been shown that the central third of the patellar tendon is significantly thicker than the medial and lateral thirds [18], and may be affected by long-term sports activity [21]. The average patellar tendon thickness in our study ranged from 3 to 5 mm, similar to the average tendon thickness described in other studies using either magnetic resonance imaging (MRI) [19], or cadaveric [16, 17] knee measurements.

The goal of the anatomical ACL reconstruction is to restore the natural anatomy. The reconstructed ACL size is determined by the harvested graft size, not by the size of the native ACL insertion site[13]. It is important to know the geometric characteristics of the graft including the length, cross-sectional area, and surface attachment of ACL in order to determine the optimal mechanical graft properties and obtain optimal ACL reconstruction results. The ACL has a "band-like" shape and does not have the same dimensions throughout its whole length [22]. Harner et al. [23] measured the cross-sectional area of the ACL mid-substance in older cadavers, and found that cross-sectional ACL mid-substance area was approximately 3.5 times smaller than the ACL tibial and femoral insertions. The tibial insertion area in 2D (projected on the tibial plateau) ranged from 114 [mm.sup.2] to 229 [mm.sup.2] [17, 24, 25], while the calculated cross-section area of the native ACL ranged from 32 to 65 [mm.sup.2], also confirmed in cadaveric studies [12, 16, 25].

If a BTB graft has the thickness of 3 mm, the width of 10 mm and the cross-sectional area (CSA) of 30 [mm.sup.2], it is still significantly smaller than a cross-sectional area of the native ACL and/or 8 mm diameter hamstring tendon graft (with 50 [mm.sup.2] of cross-sectional area) [17]. Shimizu et al. [26] and Yoshiya et al. [27] have reported that a 10-mm wide patellar tendon graft has an average CSA of 33 [mm.sup.2], while Staubli et al. [28] reported the average CSA of 36 [mm.sup.2] in a cadaveric study. For the patellar tendon graft of the average thickness (3-5 mm) [16-18] and the width of 10 mm, the CSA will be 30-50 [mm.sup.2]. Our modified BTB graft preparation technique made it possible to increase its cross-sectional area to 71-81 [mm.sup.2], and come close to the CSA of the native ACL and hamstring tendon graft (Table 2).

Regardless of whether the anatomic tunnel placement in the native footprint may be more important than a complete filling of the footprints [29], we believe that our modified BTB graft preparation allows better reconstruction of native ACL and/or hamstring tendon graft geometric characteristics. Geometric characteristics of the patellar tendon directly affect the BTB graft and the results of ACL reconstruction, and in an ideal anatomical ACL reconstruction, the geometry of the ACL graft should resemble that of the original ACL [30]. The major finding in the present study is that the modified BTB graft preparation technique made it possible to increase its CSA.

One of the possible complications associated with our modified BTB graft preparation is a rupture of the patellar tendon. We have been using this modified BTB graft preparation technique since 2006, and out of 1750 ACL reconstructions we performed during this period, only two patients developed a patellar tendon rupture 8 months after surgery associated with an intense jump [31].

The main weakness of this study is the lack of mechanical and biological testing of our graft, which is going to be addressed in our future research.


For the average thickness (3-5 mm) and width (10 mm) of the patellar tendon graft, the cross-sectional area will be 30-50 [mm.sup.2]. The modified bone-patellar tendon-bone graft preparation technique made it possible to increase its cross-sectional area to 71-81 [mm.sup.2].


BTB--bone-patellar tendon-bone

ACL--anterior cruciate ligament

CSA--corss-sectional area


[1.] Eikenbary CF. A suggested method for the repair of crucial ligaments of the knee. Surg Gynecol Obstet. 1927;45:93-4.

[2.] Jones KG. Reconstruction of the anterior cruciate ligament using the central one-third of the patellar ligament: a follow-up report. J Bone Joint Surg Am. 1970;52:1302-8.

[3.] Bruckner H. Eine neue methode der kreuzbandplastik. Chirurg. 1966;37:413-4.

[4.] Franke K. Clinical experience in 130 cruciate ligament reconstructions. Orthop Clin North Am. 1976;7:191-3.

[5.] Eriksson E. Reconstruction of the anterior cruciate ligament. Orthop Clin North Am. 1976;7:167-79.

[6.] Clancy WG Jr. Intra-articular reconstruction of the anterior cruciate ligament. Orthop Clin North Am. 1985;16:181-9.

[7.] Reinhardt KR, Hetsroni I, Marx RG. Graft selection for anterior cruciate ligament reconstruction: a level I systematic review comparing failure rates and functional outcomes. Orthop Clin North Am. 2010;41:249-62.

[8.] Milankov M, Rasovic P, Kovacev N, Milovic M, Bojat V. Fracture of the patella after the anterior cruciate ligament reconstruction. Med Pregl. 2012;65:476-82.

[9.] Auge II WK, Yifan K. A technique for resolution of graft-tunnel length mismatch in central third bone-patellar tendon-bone anterior cruciate ligament reconstruction. Arthroscopy. 1999;15:877-81.

[10.] Toritsuka Y, Horibe S, Mitsuoka T, Nakamura N, Hamada M, Shino K. Comparison between the cross-sectional area of bone-patellar tendon-bone grafts and multistranded hamstring tendon grafts obtained from the same patients. Knee Surg Sports Traumatol Arthrosc. 2003;11:81-4.

[11.] Iriuchishima T, Shirakura K, Yorifuji H, Aizawa S, Fu FH. Size comparison of ACL footprint and reconstructed autograft. Knee Surg Sports Traumatol Arthrosc. 2013;21:797-803.

[12.] Pujol N, Fong O, Karoubi M, Beaufils P, Boisrenoult P Anatomic double-bundle ACL reconstruction using a bone-patellar tendon-bone autograft: a technical note. Knee Surg Sports Traumatol Arthrosc. 2010;18:43-6.

[13.] Shino K, Nakata K, Nakamura N, Toritsuka Y, Horibe S, Nakagawa S, et al. Rectangular tunnel double-bundle anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft to mimic natural fiber arrangement. Arthroscopy. 2008;24:1178-83.

[14.] Herbort M, Tecklenburg K, Zantop T, Raschke MJ, Hoser C, Schulze M, et al. Single-bundle anterior cruciate ligament reconstruction: a biomechanical cadaveric study of a rectangular quadriceps and bone patellar tendon bone graft configuration versus a round hamstring graft. Arthroscopy. 2013;29:1981-90.

[15.] Yoo JH, Yi SR, Kim JH. The geometry of patella and patellar tendon measured on knee MRI. Surg Radiol Anat. 2007; 29:623-8.

[16.] Iriuchishima T, Yorifuji H, Aizawa S, Tajika Y, Murakami T, Fu FH. Evaluation of ACL mid-substance cross-sectional area for reconstructed autograft selection. Knee Surg Sports Traumatol Arthrosc. 2014;22:207-13.

[17.] Yanke AB, Bell R, Lee AS, Shewman E, Wang VM, Bach BR Jr. Characteristics compared with hemi-patellar tendon grafts central-third bone-patellar tendon-bone allografts demonstrate superior biomechanical failure. Am J Sports Med. 2013;41:2521-6.

[18.] Goldstein JL, Verma N, McNickle AG, Zelazny A, Ghodadra N, Bach BR Jr. Avoiding mismatch in allograft anterior cruciate ligament reconstruction: correlation between patient height and patellar tendon length. Arthroscopy. 2010;26:643-50.

[19.] Brown JA, Brophy RH, Franco J, Marquand A, Solomon TC, Watanabe D, et al. Avoiding allograft length mismatch during anterior cruciate ligament reconstruction. Am J Sports Med. 2007;35:986-9.

[20.] Toumi H, Higashiyama I, Suzuki D, Kumai T, Bydder G, McGonagle D, et al. Regional variations in human patellar trabecular architecture and the structure of the proximal patellar tendon enthesis. J Anat. 2006;208:47-57.

[21.] Grzelak P, Polguj M, Podgorski M, Majos A, Krochmalski M, Domzalski M. Patellar ligament hypertrophy evaluated by magnetic resonance imaging in a group of professional weightlifters. Folia Morphol (Warsz). 2012;71:240-4.

[22.] Triantafyllidi E, Paschos NK, Goussia A, Barkoula NM, Exarchos DA, Matikas TE, et al. The shape and the thickness of the anterior cruciate ligament along its length in relation to the posterior cruciate ligament: a cadaveric study. Arthroscopy. 2013;29:1963-73.

[23.] Harner CD, Baek GH, Vogrin TM, Carlin GJ, Kashiwaguchi S, Woo SL. Quantitative analysis of human cruciate ligament insertions. Arthroscopy. 1999;15:741-9.

[24.] Siebold R, Ellert T, Metz S, Metz J. Tibial insertions of the anteromedial and posterolateral bundles of the anterior cruciate ligament: morphometry, arthroscopic landmarks, and orientation model for bone tunnel placement. Arthroscopy. 2008;24:154-61.

[25.] Hashemi J, Chandrashekar N, Cowden C, Slauterbeck J. An alternative method of anthropometry of anterior cruciate ligament through 3-D digital image reconstruction. J Biomech. 2005;38:551-5.

[26.] Shimizu K, Yoshiya S, Kurosaka M, Sugihara T, Beppu M, Aoki H. Change in the cross-sectional area of a patellar tendon graft after anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. 2007;15:515-21.

[27.] Yoshiya S, Kurosaka M, Shoda E, Kuroda R, Shimizu K, Yamamoto T, et al. Cross-sectional area of a bone-patellar tendon-bone graft for anterior cruciate ligament reconstructon. J Knee Surg. 2003;16:75-8.

[28.] Staubli HU, Schatzman L, Brunner Rincon L, Nolte LP. Quadriceps tendon and patellar ligament: cryosectional anatomy and structural property in young adults. Knee Surg Sports Traumatol Arthrosc. 1996;4:100-10.

[29.] Bedi A, Maak T, Musahl V. O'Loughlin P, Choi D, Citak M, et al. Effect of tunnel position and graft size in single-bundle anterior cruciate ligament reconstruction: an evaluation of time-zero knee stability. Arthroscopy. 2011;27:1543-51.

[30.] Kropf EJ, Shen W, van Eck CF, Musahl V, Irrgang JJ, Fu FH. ACL-PCL and intercondylar notch impingement: magnetic resonance imaging of native and double-bundle ACL-reconstructed knees. Knee Surg Sports Traumatol Arthrosc. 2013;21:720-5.

[31.] Kovacev N, Antic J, Gvozdenovic N, Obradovic M, Vranjes M, Milankov M. Patellar tendon rupture: treatment results. Med Pregl. 2015;68(1-2):22-8.

Rad je primljen 20. VI 2015.

Recenziran 29. VI 2015.

Prihvacen za stampu 30. VI 2015.

DOI: 10.2298/MPNS1512371M

Miroslav MILANKOV (1,2), Mirko OBRADOVIC (1,2), Miodrag VRANJES (1,2) and Zlatko BUDINSKI (1,2)

University of Novi Sad, Faculty of Medicine (1)

Clinical Center of Vojvodina, Novi Sad

Department of Orthopedic Surgery and Traumatology (2)

Corresponding Author: Prof, Dr Miroslav Milankov, Klinicki centar Vojvodine, Klinika za ortopedsku hirurgiju i traumatologiju, 21000 Novi Sad, Hajduk Veljkova 1-7, E-mail:

Table 1. Geometric characteristics of the modified BTB graft

Tabela 1. Geometrijske karakterisitke modifikovanog kalema

No of patients    BTB graft circumference in mm    Diameter
Broj pacijenata   (measured at the central part)    in mm
                   (O=2r[pi])/Obim kalema u mm     Precnik
                    (mereno u sredisnjem delu)       u mm

9                               30                   9.55
15                              31                   9.87
69                              32                  10.19

No of patients    Half-diameter         Cross-sectional
Broj pacijenata       in mm           area in [mm.sup.2]
                   Poluprecnik        (P=[r.sup.2][pi]).
                      u mm        Poprecni pesek u [mm.sup.2]

9                     4.77                   71.59
15                    4.93                   76.50
69                    5.09                   81.51

O circumference/obim; P surface/povrsina, r half-diameter/
poluprecnik, [pi] = 3,14
COPYRIGHT 2015 Drustvo Lekara Vojvodine
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2015 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Author:Milankov, Miroslav; Obradovic, Mirko; Vranjes, Miodrag; Budinski, Zlatko
Publication:Medicinski Pregled
Article Type:Report
Date:Nov 1, 2015
Previous Article:Development and achievements of assisted reproductive technology/ razvoj i dostignuca asistirane reproduktivne tehnologije.
Next Article:Diagnostic role of fluorine-18 ([sup.18]F) fluorodeoxyglucose positron emission tomography computed tomography in detecting recurrent disease in...

Terms of use | Privacy policy | Copyright © 2019 Farlex, Inc. | Feedback | For webmasters