Table 1 Study characteristics.
Author, year | Level of Evidence | Sample | Single-bundle group | Double bundle group | Measures and outcomes |
|---|---|---|---|---|---|
Adravanti et al.1 | I | n = 60 Inclusion: age between 16 and 45 years, complete ACL rupture within 4 months | Single-bundle ACL reconstruction. The tibial tunnel was prepared using a dedicated elbow aimer in the posterior half of the native ACL footprint while maintaining the ACL stump. The femoral tunnel diameter was usually 7 to 8 mm and the tibial tunnel diameter 8 to 9 mm accordingly to the graft dimension. n = 30 | Double-bundle ACL reconstruction. The semitendinosus was used for the anteromedial bundle and the gracilis for the posterolateral bundle. n = 30 | Patients were evaluated preoperatively and after surgery at 6 months, 1, 3, and 6 years using the Lysholm score, IKDC form, and KT-2000 |
Ahlden et al.3 | I | n = 103 Inclusion: patients with a unilateral ACL injury and older than 18 years | Single-bundle ACL reconstruction. The femoral tunnel was first addressed. The femoral ACL insertion site was marked with a Steadman awl in the shallow aspect of the AM bundle insertion site and near the centre of the ACL footprint. n = 50 | Double-bundle ACL reconstruction. The femoral tunnels were first addressed. The femoral insertion sites of the AM and PL bundles were marked with a Steadman awl. n = 53 | Clinical assessments at the preoperative and follow-up times were as follows: pivot-shift test, KT-1000 arthrometer laxity measurements, manual Lachman test, range of motion, Lysholm knee-scoring scale, and Tegner activity scale, KOOS, 1-legged hop test, and square hop test |
Araki et al.4 | I | n = 20 Inclusion: chronic ACL deficiency in one knee and had an indication for ACL reconstruction | Single femoral and single tibial tunnels were created at the central position between the original insertion of the AMB and PLB. n = 10 | Two femoral and two tibial tunnels to reproduce the AMB and PLB. n = 10 | KT-1000 measurements, isokinetic muscle peak torque, heel-height difference, and Lysholm score at the preoperative and one-year follow-up times between these two groups |
Beyaz et al.9 | I | n = 31 Inclusion: patients without lower limb bone fractures, who had not undergone previous lower extremity surgery, and whose other knee examination was normal | In the single-bundle method, the ACL was aligned in the middle of the tibial tunnel exit. n = 16 | In the dual-bundle method, a 5 cm oblique incision was made 2 cm below and medial to the tibial tuberosity to harvest gracilis and semitendinosus tendons. n = 15 | Clinical evaluations were performed at 8 years postoperatively with the IKDC, Tegner, and Lysholm knee-scoring systems |
Bohn et al.11 | I | n = 36 Inclusion: age 18–50 years, magnetic resonance imaging-verified ACL injury with symptoms of instability, no previous knee ligament surgery, no concomitant knee ligament injuries, and an uninjured contralateral knee | The tibial bone tunnel was positioned in the intercondylaris anterior area in the centre of the native tibial ACL footprint using the inner aspect of the lateral meniscus anterior insertion area as a landmark. n = 13 | The semitendinosus tendon (for the AM bundle) and the gracilis tendon (for the PL bundle) were looped over a 20 mm EndoButton CL femoral fixation implant. n = 23 | The tibial rotation was determined during walking, running, and a pivoting task. Other outcome parameters were KT-1000 knee laxity measurements and subjective outcome scores of KOOS and IKDC |
Ebert et al.20 | II | n = 50 Inclusion: less than 60 years old, non-cartilage lesions above grade 3 or lower than 3 cm2, knee joint dislocations and partial resection of the meniscus of less than 50% | For the SB technique, a graft that was 7–9 mm in diameter and 7–9 cm in length was prepared by folding it. n = 31 | Two grafts were prepared for the DB technique. n = 19 | The VAS for pain and function, the Tegner activity score, IKDC and the Lysholm and Marshall scores were used as evaluation methods; the anterior stability (KT-1000 arthrometer measurement) and the deficits in muscle strength in extension and flexion of both knees were measured in a standardized manner one year after surgery |
Fujita et al.22 | I | n = 55 Inclusion: the patient was diagnosed with ACL insufficiency and provided informed written consent for this study | Double semitendinosus combined with double gracilis tendons for the AM bundle. n = 31 | The PL bundle graft in DB reconstruction and combined quadruple semitendinosus and double gracilis tendons in the AM and PL reconstructions; 2 femoral and 2 tibial tunnels to reproduce the AM and PL bundles for DB reconstruction were created. n = 19 | The Lysholm score, Tegner score, anterior laxity with the KT-1000 arthrometer, rotator instability with the pivot-shift test, and muscle strength with knee extensor and flexor isokinetic peak torques at 60°/s were evaluated |
Hussein et al.26 | I | n = 209 Inclusion: an ACL rupture in active patients with a closed growth plate | The procedure of anatomic single-bundle reconstruction was similar to anatomic double-bundle reconstruction. n = 78 | With the scope in the medial portal, a 3/32 Steinman pin was introduced through the accessory medial portal and placed at the centre of the PL femoral insertion site. In chronic cases, we placed it below the lateral intercondylar ridge and anterior to the bifurcate ridge. n = 138 | The outcomes were the Lysholm score and subjective IKDC form. The KT-1000 arthrometer was used to evaluate anteroposterior stability, and the pivot-shift test was used to determine rotational stability |
Jarvela et al.28 | II | n = 90 Inclusion: primary ACL reconstruction, closed growth plates, and the absence of ligament injuries to the contralateral knee | The femoral tunnel was drilled through an anteromedial portal as posterior as possible without breaking the posterior wall of the femur with a free-hand technique at approximately 10 o’clock in the right knee and 2 o’clock in the left knee. n = 60 | Two tunnels on the femoral side were made via an anteromedial portal (not transtibial) with a free-hand technique without a guide to the anatomic position of the insertion sites of each bundle. n = 30 | The evaluation methods consisted of a clinical examination, which included stability measurements using a KT-1000 arthrometer, and a manual pivot-shift test. The IKDC and Lysholm knee scores were used to evaluate the knee preoperatively and at the 10-year follow-up |
Kang et al.30 | II | n = 84 Inclusion: (1) no history of previous surgery in the injured knee; (2) no concomitant injury of other knee ligaments; (3) a healthy contralateral knee; (4) chondral lesions no more severe than grade II according to the Outerbridge classification; (5) meniscus repair or partial meniscectomy involving less than one-third of the entire meniscus; (6) no patellofemoral symptoms or absence of systemic illnesses | Single-bundle reconstruction with modified BPTB allograft was shaped into a column of 25 mm in length and 10 mm in diameter; n = 43 | For DB ACL reconstruction, tibialis anterior allografts were prepared to make 2 double-looped grafts for the AM and PL bundles. n = 41 | Clinical outcomes including Lachman and pivot-shift tests, KT-1000 arthrometer measurements, and IKDC classification; Lysholm and Tegner activity scores were compared between the two groups at the last follow-up |
Karikis et al.31 | I | n = 105 Inclusion: patients > 18 years old with a unilateral ACL injury | The femoral tunnel was addressed first. The femoral ACL insertion site was marked with an awl in the shallow aspect of the AM bundle insertion site, which is near the centre of the ACL footprint, to place the centre of the tunnel just as deep as the bifurcate ridge approximately 8 to 10 mm from the posterior cartilage at the 3 or 9 o’clock position in the notch orientation and with the knee at 90° of flexion. n = 52 | For the DB technique, both femoral and tibial remnants of AM and PL bundles were identified with the knee at 90° of flexion. The femoral tunnels were addressed first. The femoral insertion sites of the AM and PL bundles were identified and marked with an awl. n = 53 | Multiple subjective and objective clinical evaluation tests and radiographic assessments of osteoarthritis (OA) were performed including the following: the Tegner score, the pivot-shift test, KT-1000 arthrometer laxity measurements, manual Lachman test, single-legged-hop test, square-hop test, range of motion, Lysholm knee scoring scale, Tegner activity scale, or Knee injury and Osteoarthritis Outcome Score |
Koga et al.32 | II | n = 53 Inclusion: primary ACL reconstruction with an autologous semitendinosus tendon | For the SB reconstruction, 2 double-strand grafts were looped and hooked to 1 EndoButton CL. n = 25 | For DB reconstruction, 2 double-strand bundles for the anteromedial bundle (AMB) and posterolateral bundle (PLB) were created with the EndoButton CL devices. The open end of each graft was closed in the same fashion as the SB method. n = 28 | The following evaluation methods were used: clinical examination, KT-1000 arthrometer measurement, muscle strength, Tegner activity score, Lysholm score, subjective rating scale regarding patient satisfaction and sports performance level, graft retear, contralateral ACL tear, and additional meniscus surgery |
Liu et al.34 | I | n = 80 Inclusion: complete, isolated, chronic ACL lesions (mean injury-to-surgery interval, 23.5 months; range, 1.5–180 months) received an ACL reconstruction with a 6- to 8-stranded HG | The femoral tunnel was drilled through the AAMP behind the resident’s ridge as posterior as possible without breaking the posterior wall of the femur and using a 6-mm femoral guide at approximately the 10 o’clock (or 2 o’clock) position. n = 40 | On the femoral side, both the AMB and PLB tunnels were drilled through the AAMP behind the resident’s ridge as posterior as possible without breaking the posterior wall of the femur and using a 6-mm femoral guide. n = 40 | The outcome assessment was performed by a blinded independent observer using International Knee Documentation Committee (IKDC), Tegner, and Lysholm scores as well as range of motion (ROM), Lachman test, pivot-shift test, KT-2000 arthrometer side-to-side difference, and return-to-sport data |
Liu et al.35 | I | n = 42 Inclusion: 1. Men aged 18–40 at the time of surgery; 2. First ACL reconstruction surgery; 3. Single leg involvement; and 4. Able to attend preoperative assessment | For HT-SB surgery, the semitendinosus and gracilis tendons (approximately 7–9 mm in diameter) were harvested and inserted into the femoral and tibial tunnels (both approximately 7–9 mm in diameter). n = 22 | For HT-DB surgery, the semitendinosus and gracilis tendons were harvested. Two tunnels (6–7 mm in diameter for the AM tunnel and 5–7 mm in diameter for the posterolateral (PL tunnel)) were drilled over both the femur and tibia. n = 20 | The KT-1000, Lysholm, IKDC, one-leg hop test and Lachman test were performed blindly at baseline and 1-year post-reconstruction |
Mayr et al.37 | I | n = 64 Inclusion: all consecutive patients presented to the outpatient clinic with an ACL rupture | For SB ACL reconstruction, both tendons were used as a 4-strand graft; for DB reconstruction, the gracilis tendon was used as a double-strand graft to replace the anteromedial bundle and the double-strand semitendinosus tendon was used for replacement of the posterolateral bundle. n = 30 | In the DB technique, the femoral drill pin for the anteromedial bundle was placed into the proximal and anterior part of the femoral footprint of the ACL and for the posterolateral bundle was placed into the posterior and distal portion. n = 34 | A follow-up examination 2 years after surgery consisted of IKDC 2000 assessment, Laxitester measurement of anteroposterior translation regarding rotational stability, and radiographic evaluation |
Mayr et al.38 | I | n = 64 Inclusion: all consecutive patients presented to the outpatient clinic with an ACL rupture | For SB ACL reconstruction, both tendons were used as a 4-strand graft; for DB reconstruction, the gracilis tendon was used as a double-strand graft to replace the anteromedial bundle and the double-strand semitendinosus tendon was used for replacement of the posterolateral bundle. n = 30 | In the DB technique, the femoral drill pin for the anteromedial bundle was placed into the proximal and anterior part of the femoral footprint of the ACL and for the posterolateral bundle was placed into the posterior and distal portion. n = 34 | A follow-up examination 5 years after surgery consisted of IKDC 2000 assessment, Laxitester measurement of anteroposterior translation regarding rotational stability, and radiographic evaluation |
Misonoo et al.42 | II | n = 44 Inclusion: patients whose ACL was reconstructed using either a SB o rDB method | For the SB reconstruction, the semitendinosus tendon was used as two double stranded grafts. First, using a tibial guide, the tibial tunnel was created at the centre of the ACL footprint. n = 22 | In the technique used for DB reconstruction, two femoral and two tibial tunnels were created under controlled arthroscopic visualization to anatomically reproduce both the AM and PL bundle using the hamstring tendon graft. n = 22 | Clinical assessment, including Tegner score, Lysholm score, and knee arthrometric measurement, revealed a restoration of the reconstructed knee stability |
Sasaki et al.49 | I | n = 14 Inclusion: unilateral ACL reconstruction | Single-bundle ACL reconstruction with Patellar Tendon: either the modified transtibial technique or the transportal technique was selected during surgery depending on accessibility to the femoral ACL insertion. A 10 mm-wide bone-patellar tendon-bone graft was harvested from the central portion of the patellar tendon with approximately 15 mm–long bone plugs on both ends. n = 5 | Double-bundle ACL Reconstruction with Hamstring Tendon: the semitendinosus tendon was usually harvested with a tendon harvester. The distal and proximal half of the semitendinosus tendon was looped and used as the AMB and PLB graft, respectively. n = 9 | Clinical outcomes (knee flexion (ROM), heel-height difference, side-to-side difference in anterior laxity, rotational laxity, and Tegner activity score) were compared between the DB and SB groups and an examination of factors affecting subjective outcomes (KOOS results) was performed |
Song et al.50 | II | n = 130 Inclusion: patients with ACL injury, chondral lesions less than the Outerbridge grade of 3, and with or without meniscal injury | For the SB ACLR, the tibialis anterior allograft was also prepared as a single-looped graft (diameter, 8–9 mm). After tibial tunnel preparation at the centre of the ACL insertion, a femoral tunnel at the centre of the footprint was created through the anteromedial portal. n = 65 | For DB reconstruction, fresh-frozen tibialis anterior allografts were prepared to make 2 single-looped grafts of 6-mm diameter for PLB and of 7-mm diameter for AMB. n = 65 | The stability results were evaluated using the Lachman and pivot-shift tests and stress radiography. Additionally, the functional outcomes were based on the Lysholm knee score, Tegner activity score, and IKDC subjective scale |
Ventura et al.54 | II | n = 80 Inclusion: 18 to 45 years old; primary ACL reconstruction; absence of concomitant cartilage, ligament, or meniscal pathology requiring surgery; and no history of knee injury or lower limb pathology | Patients belonging to the SB group underwent SB reconstruction with doubled hamstrings. n = 40 | Patients belonging to the DB group underwent DB reconstruction using a 2-stranded semitendinosus tendon for the AM bundle and a 2-stranded gracilis tendon for the PL bundle. n = 40 | Patients were assessed preoperatively with functional assessment including the International Knee Documentation Committee 2000 knee subjective form and visual analogue scale as well as physical examination (including the pivot-shift test and instrumented knee laxity measurement). Vertical jump assessment with the Optojump system has been introduced as a method comparing functional ability between the 2 surgical techniques. The same protocol was repeated at 6 months, 12 months, and 2 years after surgery |
Volpi et al.55 | II | n = 40 Inclusion: specific sports activities age 18–45, no additional ligamentous lesions, absence of rheumatic pathologies, type IV Outerbridge chondral lesions, axial deviation of the knee, and any previous surgery to the examined knee | Single-bundle ACL reconstructions with the patellar tendon were performed using two re-absorbable cross pins for the femoral fixation and both tibial rigid fix and re-absorbable pins for the tibial fixation. n = 20 | Double-bundle ACL reconstruction with semitendinosus and gracilis tendons were performed using the transtibial technique with a dedicated guide. The femoral fixation of both PL and AM bundles was achieved with pins, while for the tibial side, both bundles were fixed with a metal staple or bioscrew at 108° and 45–50° of flexion, respectively. n = 20 | Clinical assessment, including Tegner score, Lysholm score, IKDC and KT-1000 |
Xu et al.58 | I | n = 80 Inclusion: primary ACL rupture in adult patients | The procedure was similar to the anatomic double-bundle reconstruction. The femoral tunnel was also created through the accessory medial portal, but the centre of the tunnel was placed in the middle of the insertion site. n = 40 | The AM and PL tunnels on the femur were drilled based on the identified insertion sites through the accessory medial portal. n = 40 | Pre- and post-operatively, all patients received a preoperative examination, including Lachman, anterior drawer, and pivot shift testing, and were also tested with KT-1000 arthrometer with a knee flexion of 30 and 90° and a manual maximum force. All patients were also evaluated with the IKDC subjective score, Lysholm score and Tegner score |
Zaffagnini et al.60 | I | n = 79 Inclusion: positive clinical examination with (Lachman test, anterior drawer test and pivot-shift test) respect to a contra-lateral normal knee. Patients with medial and lateral meniscal injuries, grade 1 or 2 MCL injuries and Outerbridge 1 or 2 chondral lesions were also included | Autologous LSBPTB technique: BPTB autograft was harvested through a single straight midline incision. In all cases, we used the central third of the ipsilateral patellar tendon. n = 39 | naDBH technique: Semitendinosus and gracilis tendons from the ipsilateral limb were harvested with an open tendon stripper. n = 40 | Patients were subjectively and objectively evaluated using the IKDC score, Tegner level, and manual maximum displacement test with a KT-2000TM arthrometer. Radiographic evaluation was performed according to the IKDC grading system and the re-intervention rate for meniscal lesions was also recorded |
Zhang et al.61 | I | n = 94 Inclusion: primary ACL reconstruction with no combined PCL injury, lateral collateral ligament injury, PL rotatory instability or fracture about knee joint, no subtotal or total meniscectomy, no previous knee ligament surgery, no arthritic changes, no malalignment and a normal contralateral knee | In single-bundle reconstruction, a tibial tunnel was first made by inserting a 2.0 Kirschner wire into the centre of ACL insertion to the tibia and then drilling with a cannulated drill and a dilatar to create a bone tunnel with the same diameter as the tendon graft. n = 49 | In double-bundle reconstruction, a 2.0 Kirschner wire was inserted posterior to the footprint of ACL insertion into the tibia via the Pro-trae ACL guide system; then, a dilatar and a cannulated drill were used to create a bone tunnel with the same diameter as the PL bundle of the graft. n = 45 | The rotational stability, as evaluated by the pivot-shift test, was significantly superior in Group DB compared to that in Group SB. No significant difference regarding ACL revisions, total flexion work, mean peak flexion torque and extension work between the groups was detected using the Tegner activity score, the knee injury and osteoarthritis outcome score, the Lysholm functional score, anterior knee pain or mobility, and subjective knee function. In addition, the Lachman test or the KT-1000 maximum manual force test was investigated |
