Anterior cruciate ligament reconstruction using

Anterior cruciate ligament reconstruction using autologous hamstring double bundle graft compared with single bundle procedures S. A. R. Ibrahim, F. Hamido, A. K. Al Misfer, A. Mahgoob, S. A. Ghafar, H. Alhran From Al Razi Orthopaedic Hospital, Safat, Kuwait

S. A. R. Ibrahim, FRCS, MDOrth, Consultant Department of Sports Unit F. Hamido, FRCS, Orthopaedic Surgeon A. K. Al Misfer, MD Phd, Orthopaedic Surgeon A. Mahgoob, FRCS, Orthopaedic Surgeon S. A. Ghafar, MS, Orthopaedic Surgeon H. Alhran, FRCS, Orthopaedic Surgeon Al Razi Orthopaedic Hospital, P O Box 4235 Safat, Code 13043, Kuwait. Correspondence should be sent to Dr S. A. R. Ibrahim; e-mail: [email protected] ©2009 British Editorial Society of Bone and Joint Surgery doi:10.1302/0301-620X.91B10. 21886 $2.00 J Bone Joint Surg [Br] 2009;91-B:1310-15. Received 10 October 2008; Accepted after revision 10 June 2009

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A total of 218 patients with unilateral anterior cruciate ligament deficiency were randomly assigned to one of four groups. In group A an anatomical double bundle anterior cruciate ligament reconstruction was performed; group B were treated by a single bundle using an Endobutton for femoral fixation; in group C by a single bundle using RigidFix cross pins for femoral fixation; and in group D by a single bundle using a bioabsorbable TransFix II screw for femoral fixation. For tibial fixation a bioabsorbable Intrafix interference screw was used for all the groups and the graft was fashioned from the semitendinosus and gracilis tendons in all patients. In all, 18 patients were lost to follow-up. The remaining 200 were subjected to a clinical evaluation, with assessment of the anterior drawer, Lachman’s and the pivot-shift tests, and KT-1000 arthrometer measurement. They also completed the International Knee Documentation Committee, Lysholm knee and Tegner activity scores. At a mean of 29 months (25 to 38) follow-up there were no significant differences concerning time between injury and range of movement and Lysholm knee scores among the four groups. However, the double bundle method showed significantly better results for the pivot-shift test (p = 0.002). The KT 1000 measurements showed a mean difference between the reconstructed knee and the patients’ normal knee of 1.4 mm in the double bundle group and 2.4 mm in the single bundle group; which was statistically significant. The Lachman and anterior drawer tests also showed superior results for the double bundle method. The International Knee Documentation Committee scale showed no significant difference among the groups (p < 0.001). On clinical evaluation the double bundle group showed less laxity than the single bundle groups. However, regardless of the technique, all knees were improved by anterior cruciate ligament reconstruction compared with their pre-operative status.

Anatomical and biomechanical studies have shown that the anterior cruciate ligament (ACL) comprises two principal bundles, the anteromedial and the posterolateral.1,2 Conventional single bundle techniques of ACL reconstruction have focused on the restoration of the anteromedial bundle while paying limited attention to the posterolateral bundle.3-5 Single bundle ACL reconstructions successfully restore anterior, but not rotational, stability.3,4 Anatomical double bundle reconstructions have been shown in a cadaver model to more closely restore normal kinematics to the knee than a single bundle method.5 Many different techniques are described for ACL reconstruction with two bundles.6-12 A lower placement of the femoral tunnel is considered to resist the rotational load of the knee better than a high position.13 The advantage of double bundle ACL reconstruction is a nearer approximation to the natural insertions of the ACL on the

tibia and the femur, thereby recreating normal biomechanical function more closely.9-11 However, it can be difficult to create a sufficiently low position of the femoral tunnel using a transtibial technique. With the anteromedial portal technique, femoral and tibial tunnels can be placed independently which allows a more anatomical placement of the femoral tunnel.14 Yasuda et al15 described a comparative study of three operative techniques. Their double bundle reconstruction was statistically significantly better than a single bundle procedure using semitendinosus and gracilis tendons, based on anterior stability measured with a KT-1000 arthrometer (MEDmetric, San Diego, California) and a pivot-shift test.16 Muneta et al11 reported that double bundle reconstruction was better than single bundle, based on the Lachman test17 and anterior stability measured with the KT-1000 arthrometer. Conversely, others have found no THE JOURNAL OF BONE AND JOINT SURGERY

ACL RECONSTRUCTION USING AUTOLOGOUS HAMSTRING DOUBLE BUNDLE GRAFT COMPARED WITH SINGLE BUNDLE PROCEDURES

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Table I. Patient data Group Patients

A

B

C

D

Time range between injury and operation (mths)

2 to 4.5

2 to 3.7

2 to 3.6

2 to 4

Operative finding meniscus injury

20 medial 12 lateral


19 medial 9 lateral


Age range in yrs

21 to 32

22 to 33

21 to 31

22 to 30

Weight range in kg

75 to 90

70 to 90

70 to 85

73 to 86

difference between single and double bundle ACL reconstruction using multi-stranded hamstring tendons.6,7 The aim of this study was to evaluate the results of double bundle ACL reconstruction using an anteromedial portal and doubled semitendinosus and double gracilis tendon autografts, with two tunnels on the femoral and the tibial sides, using Endobutton (Smith and Nephew, Andover, Massachussetts) fixation on the femoral side and Intrafix Bioabsorbable interference screws (Mitek, Johnson and Johnson, Westwood, Massachussetts) on the tibial side. In a prospective, randomised trial, this method was compared with a single bundle four-stranded hamstring autograft technique using similar fixation on the tibial side but different fixation in the femur. Our first hypothesis was that post-operative anterior laxity, measured with KT1000, the pivot-shift test and subjective evaluation after the anatomical double bundle ACL reconstruction with hamstring graft, would be significantly better than single bundle reconstruction using the same graft. The second hypothesis was that there would be no significant differences in the other clinical measures between the procedures.

Patients and Methods We randomised 218 men with ACL deficiency into four groups, each using a different technique to secure their hamstring tendon grafts. The randomisation was by a closed envelope method. None of the patients had medial, lateral or posterior laxity on physical examination. The mean time between injury and operation was three months (2 to 4). In all, 200 patients were available for a mean follow-up of 29 months (25 to 38). The remaining 18 were living abroad and were unavailable for review. The mean age of the patients was 28 years (21 to 33) at the time of operation. There was no difference regarding the delay between the injury and operation, operative findings, follow-up time, age, height, weight and gender between the groups (Table I). All the reconstructions were undertaken by an experienced orthopaedic surgeon (SARI). A well-trained orthopaedic surgeon (FH), who was blind to the procedure, performed the pivot-shift test. Surgical technique. A diagnostic arthroscopy was performed through standard anteromedial and anterolateral VOL. 91-B, No. 10, OCTOBER 2009

portals. The gracilis and semitendinous tendon grafts were then harvested through a longitudinal incision 2 cm to 3 cm medial to the tibial tuberosity. For single bundle reconstruction, the harvested tendons were folded four times and for double bundle reconstruction the semitendinosus was doubled to reconstruct the anteromedial bundle and gracilis was doubled to reconstruct the posterolateral bundle. Double bundle: group A (n = 50). Double bundle ACL reconstruction was undertaken using the Acufex (Smith & Nephew, Andover, Massachusetts) director tools for anatomical ACL reconstruction.18 The method requires two femoral and two tibial tunnels whose centres corresponded to the centres of the anatomical anteromedial and posterolateral attachments of the ACL. The femoral tunnels were drilled independently through the anteromedial portal, aimed at the natural femoral ‘footprint’. The tibial tunnels were drilled independently using a dedicated tibial aiming device. The grafts were secured to the femur using Endobuttons and tibial fixation was by Intrafix bioabsorbable screws. Single bundle: group B (n = 48). The tibial tunnel was drilled using the Acufex tibial guide and a standard cannulated drill bit which matched the diameter of the graft. For the femoral tunnel, an appropriate offset hook was placed at the ‘over the top’ positions of 2 o’clock and 10 o’clock for left and right knees, respectively. A drill bit of the diameter of the graft was passed through the tibial tunnel then on through the femur. A depth gauge was used to measure the total length of the femoral channel and the graft was marked with a line placed on the graft 6 mm distal to the total channel length. The graft was then pulled into the femoral tunnel until the marking line just entered the femur, where upon the suture was tied over an Endobutton and the tibial end secured with an Intrafix screw. Single bundle: group C (n = 52). The tibial hole was made in a standard fashion using the Mitek aiming guides (Johnson & Johnson) which enable transtibial drilling of the femur at the correct position to a depth of 30 mm. Using the Mitek cross-pin guide, two cross-pin locking holes were fashioned from the lateral aspect of the femur. This allowed transfixation of the femoral end of the graft with two RigidFix cross-pins (Mitek) once the graft had been drawn into the femoral tunnel to a depth of 30 mm. After tensioning, the tibial end of the graft was secured with an Intrafix screw.

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Table II. Post-operative results of assessment of knee laxity at a mean of 29 months Test

Group A (n = 50)

Group B (n = 48)

Group C (n = 52)

Group D (n = 50)

Lachman’s test Negative Grade I Grade III Grade IV

45 5 0 0

31 10 7 0

38 9 5 0

37 7 6 0

p = 0.04

Anterior drawer test Negative Grade I Grade II Grade III Grade IV

45 5 0 0 0

32 13 3 0 0

35 17 0 0 0

32 18 0 0 0

p = 0.03

KT-1000 arthrometer at 20 lbs 0 to 2 3 to 5 >5

47 3 0

32 10 6

38 6 8

38 7 5

p = 0.04

Single bundle: group D (n = 50). The

tibial tunnel was drilled in a standard fashion at the site of ACL footprint, creating a tunnel that matched the diameter of the graft. A transtibial femoral tunnel was prepared using the Arthrex guides (Arthrex, Naples, Florida), enabling correct positioning of the prepared graft. The femoral end was secured with a TransFix II screw (Arthrex) and the tibial end with an Intrafix screw (Mitek). In all groups the graft was tensioned to 20 lb to 30 lb of force. With regard to associated meniscal injury, 20 knees in group A had medial and 12 had lateral meniscal tears. In group B, 18 had medial and ten had lateral injuries; in group C 19 had medial and nine had lateral; and in group D, 19 had medial and 11 had lateral meniscal injuries. All injured menisci were repaired with the exception of partial excision of six medial and two lateral menisci in group A, four medial and three lateral in group B, seven medial and four lateral in group C and six medial and four lateral in group D. Grade I chondral lesions were seen in six patients, two in group A, two in group B, one in group C and one in group D. All were treated conservatively without surgery. The same pre- and post-operative programme was used for all groups. Rehabilitation. Rehabilitation was the same for all patients. Immediate full weight-bearing and full range of movement were permitted according to their pain tolerance. Crutches were employed for one to two weeks and braces were not used. Closed-kinetic chain quadriceps exercises were started immediately. Cycling was permitted with an ergonometer four to five weeks post-operatively, running allowed at three months, and sports involving pivoting on the treated knee at six months, after the patient had regained full functional stability. In those patients who required a meniscal repair, the programme was modified to restrict knee flexion to 90° for the first five to six weeks.

p = 0.01

Evaluation was performed by clinical examination, a patient satisfaction questionnaire, measurement of joint laxity with the KT-1000 arthrometer (MED metric, San Diego, California), the International Knee Documentation Committee Scale (IKDC)19 and Lysholm and Tegner activity scores.20 Data were analysed using the SPSS 11.0 (SPSS Inc., Chicago, Illinois). The difference of means was undertaken by analysis of variance (ANOVA), paired sampled t-tests and, where appropriate, by the chi-squared test. The significance level was set at p < 0.05.

Results At a mean follow-up of 29 months (25 to 38), rotational stability as evaluated by the pivot-shift test was significantly better in patients in whom the double bundle technique had been undertaken than with any of the single bundle methods. In group A (p = 0.002), 48 patients (96%) had normal rotational stability, but only 20 patients (42%) in group B, 24 patients (46%) in group C and 21 (42%) in group D had rotational laxity of grade I (p = 0.002) (Table II). However, in all groups, the rotational laxity was significantly better at a mean of 29 months (25 to 38) than preoperatively (p < 0.001) (Table III). Manual knee laxity testing with Lachman’s and the anterior drawer tests17 showed that significantly better results were obtained with the double bundle method than the single bundle methods (p = 0.04 and p = 0.03 respectively, Table II). Anterior knee laxity measurements were performed with the KT-1000 arthrometer with an anteriorly directed force of 20 lbs and demonstrated a mean difference in the anterior translation of 1.2 mm (SD 1.8) between the reconstructed and normal knee in all patients. The mean difference when exerting a manual maximum anterior force was 2 mm (SD 1.8). On comparing the anterior translation THE JOURNAL OF BONE AND JOINT SURGERY


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Table III. Results of the pivot-shift test performed pre- and post-operatively Pivot-shift test

Group A (n = 50)

Group B (n = 48)

Group C (n = 52)

Group D (n = 50)

Pre-operatively Normal Nearly normal Abnormal Severely abnormal (%)

0 15 26 9

0 13 28 7

0 14 31 7

0 12 29 9 (18) NS*

Post-operative at a mean of 29 months Normal Nearly normal Abnormal Severely abnormal

48 2 0 0

20 22 6 0

24 24 4 0

21 24 5 0

* NS, not significant

Table IV. Lysholm knee score at a mean 29 month’s follow-up Scores

Group A (n = 50)

Group B (n = 48)

Group C (n = 52)

Group D (n = 50)

(A) Excellent (95 to 100) Good (84 to 94) Fair (65 to 83) Poor

26 23 1 0

20 21 7 0

23 23 6 0

24 22 4 0

(B) Pre-operatively 8 to 9 7 to 8 6 to 7

0 15 35

0 17 31

0 18 34

0 13 37

Post-operatively at a mean of 29 months 7 to 9 6 to 8 5 to 6

37 10 3

31 10 7

33 13 6

31 14 5

between the groups when exerting a manual maximum pull, none of the patients in group A showed more than 5 mm difference between their knees. In the single bundle groups, 19 patients showed more than 5 mm difference (six in group B, eight in group C and five in group D). This difference between the double bundle method and all the single bundle methods was statistically significant (p = 0.04 and p = 0.03 respectively, Table II). At a mean follow-up of 29 months (25 to 38) all patients had full extension of the knee except for two who showed an extension lag, one in group A and one in group B. Only five patients lacked full flexion, with a deficit of 10° to 15°. This was found in one patient in group A, two in group B and one each from groups C and D. Lysholm knee scores and Tegner activity scores showed no significant differences between any of the groups (Table IV). Similarly, the IKDC scores at a mean of 29 months (25 to 39) follow-up showed no significant difference between the groups, with all showing significant improvements compared with their preoperative scores (p < 0.001, Table V). All 200 patients played sport before their injury, with 179 (89.5%) returning to their pre-injury level. However, VOL. 91-B, No. 10, OCTOBER 2009

21 patients had to return to a lower level of activity (one in group A, ten in group B and five each in groups C and D), but none had to give up sport completely. In response to the satisfaction questionnaire, 47 (94%) patients in group A, 35 (73%) in group B, 42 (81%) in group C and 41 (82%) in group D were satisfied with their outcome. Complications. In group A, two of the earlier procedures had migration of the Endobuttons from the lateral femoral cortex. This caused some pain on flexion at 20 to 22 months post-operatively and necessitated their removal at 23 months. Two patients in group A had superficial wound infections, which were treated conservatively with antibiotics and settled. Two patients in group D and one in group C reinjured their knee and disrupted the repair of their sutured menisci, which were removed arthroscopically.

Discussion At short-term follow-up, this study showed that anatomical double bundle ACL reconstruction had significantly better rotational stability when evaluated by the pivot-shift test than patients with a single bundle ACL reconstruction. Assessment of anterior laxity with Lachman’s and the ante-

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Table V. Evaluation of the knee by the International Knee Documentation Committee (IKDC) score pre-operatively and at a mean 29 months’ follow-up IKDC grade*

Group A (n = 50)

Group B (n = 48)

Group C (n = 52)

Group D (n = 50)

Pre-operatively A B C D

0 0 45 4

0 1 43 4

0 2 41 9

0 3 44 3

28 19 5 0

27 18 5 0

At mean 29 months follow-up A 32 23 B 17 20 C 1 5 D 0 0 * A, normal; B, nearly normal; C, abnormal; D, severely abnormal

rior drawer test also showed the double bundle to be superior to the single bundle methods. Furthermore, none of the patients with a double bundle repair had more than a 5 mm difference between the reconstructed and normal knee in KT-1000 measurements obtained when exerting a maximum pull, whereas 14 (9%) of single bundle patients had more than a 5 mm difference. The Endobutton group (B) had slightly more laxity than others along with slight differences on the Tegner and IKDC scales, which we suspect may be due to poorer femoral fixation of the graft. We believe the superiority of the double bundle might in part be due to the anatomical placement of the femoral fixation obtained using the anteromedial portal for drilling, rather than drilling the femur using the transtibial route in the single bundle groups. It has been reported elsewhere that there are no clinically relevant differences between the double and single bundle techniques.6,8 Both are said to provide satisfactory stability and show no significant difference between the laxity measurements and the subjective result. Hara et al21 described a double bundle ACL cruciate ligament reconstruction using a posteromedial portal technique. It was noted that this technique could avoid overlapping of the two femoral tunnels and damage to the posterior cortex of the lateral condyle on the femur during the preparation of the posterolateral bundle. It was also stated that this method required only one tibial tunnel for both bundles. Muneta et al11 described a two-year followup study with 54 consecutive patients using a double bundle technique with cortical fixation on the femoral side and found that ten patients had grade I rotation in the pivot-shift test and none showed more than a 5 mm difference in KT1000 arthrometer testing. They suggested that two separate tunnels were needed on the tibial as well as on the femoral side to better mimic the normal anatomy of the ACL. Petersen et al22 stated that anatomical double bundle reconstruction with two tibial and two femoral tunnels restores anterior tibial translation and biomechanics, particularly as the knee nears full extension. Zantop et al23,24 noted that the femoral centres of the posterolateral and anteromedial bundle are not in the same plane and change their orientation

throughout passive knee flexion. The tibial centre of the anteromedial bundle is aligned with the anterior horn of the lateral meniscus, whereas the tibial centre of the posterolateral bundle is located at the site recommended for the tibial tunnel in single bundle ACL reconstruction, namely 7 mm to 9 mm anterior to the PCL. They concluded that the femoral centre of the posterolateral bundle is shallow and inferior to that of the anteromedial bundle. They also observed that the anteromedial and posterolateral bundles stabilise the knee in response to anterior tibial loads and combined rotatory forces in a synergistic manner. In our method we were able to prepare two femoral tunnels positioned correctly without damaging the lateral femoral cortex or requiring a posteromedial portal. Other descriptions of the double bundle technique have noted good results with this method.15,25,26 Conversely, Asagumo et al27 found there was no significant difference in outcome between the double bundle reconstruction and single bundle with regard to manual laxity, anterior laxity measured by the KT-1000 arthrometer, knee extension and flexion strength, and Lysholm score. In our study, the Lysholm, Tegner activity and IKDC scores were nearly equal in all groups, whereas rotational and anterior stability of the knee was better in the double bundle group. However, the differences in the IKDC scores were not statistically significant and all patients in our study were able to play their original sport. We suggest that the superior rotational stability of the double bundle group might protect the knee from a new injury, particularly in sports that involve pivoting. We accept that our study has some limitations as the numbers of patients in each group was not large and the mean follow-up was only 27 months, but there were significant and important differences among the groups. The pivot-shift test can be difficult to perform but we are unaware of any other simple way of measuring rotational instability of the knee. In contrast, anterior laxity of the knee could be measured with the KT-1000 arthrometer, which is a recognised instrument after ACL reconstruction. Muneta et al28 found that anterior laxity evaluated by a THE JOURNAL OF BONE AND JOINT SURGERY


combination of the KT-1000 arthrometer, pivot-shift Lachman tests revealed that the double group gave statistically significantly better results than the single bundle reconstructions and our findings support this. Although all the techniques used gave almost equal clinical results, the method of double bundle ACL reconstruction produced better rotational stability than single-bundle reconstruction using different fixation techniques on the femoral side and the same fixation on the tibial side. No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.

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arthroscopic reconstruction of the anterior cruciate ligament. Am J Sports Med 2002;30:523-36. 13. Loj JC, Fukuda Y, Tsuda E, et al. Knee stability and graft function following anterior cruciate ligament reconstruction: comparison between 11 o’clock femoral tunnel placement. Arthroscopy 2003;19:297-304. 14. Harner CD, Baek GH, Vogrin TM, et al. Quantitative analysis of human cruciate ligament insertions. Arthroscopy 1999;15:741-9. 15. Yasuda K, Konddo E, Ichiyama H, Tanabe Y, Yohyama H. Clinical evaluation of anatomic double-bundle anterior cruciate ligament reconstruction procedure using hamstring tendon grafts: comparison among 3 different procedures. Arthroscopy 2006;22:240-51. 16. Fetto JF, Marshall JL. Injury to the anterior cruciate ligament producing the pivotshift sign. J Bone Joint Surg [Am] 1979;61-A:710-14. 17. Jonsson T, Althoff B, Peterson L, Renström P. Clinical diagnosis of ruptures of the anterior cruciate ligament: a comparative study of the Lachman test and the anterior drawer sign. Am J Sports Med 1982;10:100-2. 18. Bellier G, Christel P, Colombet P, et al. Double strand hamstring graft for anterior cruciate ligament reconstruction. Arthroscopy 2004;20:890-4. 19. Irrgang JJ, Ho H, Harner CD, Fu FH. Use of the International Knee Documentation Committee guidelines to assess outcome following anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc 1998;6:107-14. 20. Lysholm J, Gillquist J. Evaluation of the knee ligament surgery results with special emphasis on use of scoring system. Am J Sports Med 1982;10:150-4. 21. Hara K, Arai Y, Ohta M, et al. A new double anterior cruciate ligament reconstruction using the posteriormedial portal technique with hamstrings. Arthroscopy 2005;21:1274. 22. Petersen W, Tretow H, Weimann A, et al. Biomechanical evaluation of two techniques for double bundle anterior cruciate ligament reconstruction one tibial tunnel versus two tibial tunnels. Am J Sports Med 2007;35:228-34. 23. Zantop T, Wellermann M, Fu FH, Petersen W. Tunnel positioning of anteromedial and posterolateral bundles in anatomic anterior cruciate ligament reconstruction: anatomic and radiographic findings. Am J Sports Med 2008;36:65-72. 24. Zantop T, Herbort M, Raschke, Fu FH, Petersen W. The role of the anteromedial and posterolateral bundles of the anterior cruciate ligament in anterior translation and internal rotation. Am J Sports Med 2007;35:223-7. 25. Yasuda K, Kondo E, Ichiyama H, et al. Anatomic reconstruction of the anteromedial and posterolateral bundles of the anterior cruciate ligament reconstruction procedure using hamstring tendon grafts: comparison among 3 different procedures. Arthroscopy 2004;20:1015-25. 26. Marcacci M, Mogora A, Zaffagini S, et al. Anatomic double bundle anterior cruciate reconstruction ligament with hamstring. Arthroscopy 2003;19:540-6. 27. Asagumo H, Kimura M, Kabayashi Y, Taki M, Takagishi K. Anatomic reconstruction of anterior cruciate ligament using double bundle hamstring tendons: surgical techniques, clinical outcomes and complications. Arthroscopy 2007;23:602-9. 28. Muneta T, Koga H, Mochizuki T, et al. A prospective randomized study of 4 strand semitendinosus tendon anterior cruciate ligament reconstruction comparing single bundle and double bundle techniques. Arthroscopy 2007;23:618-28.