Single femoral socket double-bundle anterior cruciate ligament reconstruction using tibialis anterior tendon: description of a new technique

Editorial Commentary: Proper Anterior Cruciate Ligament Graft Choice Mitigates Against the Need for Anterolateral Ligament Reconstruction

It is not coincidence that fervor surrounding anterolateral ligament (ALL) reconstruction increased as double-bundle anterior cruciate ligament reconstruction (ACLR) enthusiasm cooled. But perhaps we shifted our focus too soon, or perhaps we shifted our focus too much. But we must remember that the ACL is primary. Increases in ACL graft diameter by 1 or 2 mm can significantly increase graft strength and decrease revision rate. Biomechanical and clinical evidence suggests that quadriceps tendon ACLR and patellar tendon ACLR demonstrates less pivot shift phenomena than hamstring ACLR. In addition, As biologically active suture tapes become more mainstream, augmented allografts are an increasingly attractive option. Proper ACL graft choice mitigates against the need for ALL reconstruction. Risk factors for anterolateral rotatory instability may include low body mass index and lateral meniscal pathology, in addition to the well-known risks such as age, gender, activity level, and revision cases. Perhaps lateral extra-articular tenodesis should be reserved for high-risk cases.

Arthroscopic reconstruction of anterior cruciate ligaments with allograft: single-tunnel single-bundle versus single-tunnel double-bundle techniques

Purpose

To compare the clinical results of anterior cruciate ligament (ACL) reconstruction using the single-tunnel single-bundle (STSB) technique versus the single-tunnel double-bundle (STDB) technique.

Methods

This was a retrospective, single-center, single-surgeon study based on data collected from March 2012 to June 2013. According to our inclusion/exclusion criteria, a total of 78 patients (64 males, 14 females; mean age, 25.1 years) who underwent arthroscopic ACL reconstruction with anterior tibialis tendon allografts through either the STSB technique (36 cases) or the STDB technique (42 cases) in our department were recruited. The International Knee Documentation Committee (IKDC), Lysholm, and Tegner scores were used to evaluate the subjective function of the knee joint during the postoperative follow-up. The Lachman test and pivot shift test were used to objectively assess the stability of the knee.

Results

The average follow-up duration was 24.9 ± 1.8 months in the STSB group and 24.6 ± 1.7 months in the STDB group (P > 0.05). Patients in both groups recovered to the preoperative sports level with few complications. The postoperative Lysholm score (86.1 ± 7.5 vs. 47.7 ± 9.0 in the STSB group; 87.0 ± 7.1 vs. 48.2 ± 8.3 in the STDB group), IKDC score (87.8 ± 7.2 vs. 49.3 ± 6.1 in the STSB group; 88.7 ± 6.6 vs. 49.8 ± 6.3 in the STDB group), Tegner score (6.5 ± 1.3 vs. 2.5 ± 1.3 in the STSB group; 6.6 ± 1.2 vs. 2.6 ± 1.2 in the STDB group), Lachman test positive rate (8.3% vs. 89.9% in the STSB group; 7.1% vs. 85.7% in the STDB group), and pivot shift test positive rate (27.8% vs. 63.9% in the STSB group; 7.1% vs. 69.0% in the STDB group) were significantly improved compared to the preoperative status in both groups (P < 0.05). However, no statistically significant difference was observed between the two groups at the final follow-up (P > 0.05), except for the pivot shift test positive rate in the STDB group versus the STSB group (7.1% vs. 27.8%, P < 0.05).

Conclusions

The STDB technique achieved a satisfactory clinical outcome with better rotational stability compared to the traditional STSB technique and therefore provided an effective option for ACL reconstruction.

Level of evidence

Case series, Level IV.

Single-tunnel anatomic double-bundle anterior cruciate ligament reconstruction has the same effectiveness as double femoral, double tibial tunnel: A prospective randomized study

PURPOSE

To investigate whether single femoral, single tibial tunnel anatomic double-bundle anterior cruciate ligament (ACL) reconstruction is equal to or superior to double femoral, double tibial tunnel ACL double-bundle anatomic reconstruction in terms of restoring the stability and functions of the knee joint.

METHODS

A prospective clinical study was performed to compare 30 cases of single-tunnel ACL double-bundle anatomic reconstruction to 28 cases of double-tunnel ACL double-bundle anatomic reconstruction, with average follow-up of 36 months. All graft tendons were hamstring tendon autografts. Tunnel placements in all the cases were made anatomically. Clinical results were collected after reconstruction. Graft appearance, meniscus status and cartilage state under arthroscopy were compared and analyzed.

RESULTS

Tunnel placements were in the anatomic positions in both groups. On the lateral pivot-shift test performed at 36 months postoperatively, there was no significant difference between groups. Clinical results such as International Knee Documentation Committee score, Tegner activity scale, and range of motion showed no significant differences between the groups. The mean thickness of anteromedial graft was reduced by 10.3% and that of the posterolateral graft was reduced by 11.1% from the original graft thickness evaluated by magnetic resonance imaging. No new meniscal tears were found either group; however, cartilage damage occurred in the double-tunnel group at 39.3%, and this rate was significantly higher than that in the single-tunnel group (10.0%).

CONCLUSION

Single femoral, single tibial tunnel anatomic double-bundle ACL reconstruction has the same effectiveness as the double femoral, double tibial tunnel in restoring the knee's stability and functions.

Kinematic Analysis of Five Different Anterior Cruciate Ligament Reconstruction Techniques

Several anatomical anterior cruciate ligament (ACL) reconstruction techniques have been proposed to restore normal joint kinematics. However, the relative superiorities of these techniques with one another and traditional single-bundle reconstructions are unclear. Kinematic responses of five previously reported reconstruction techniques (single-bundle reconstruction using a bone-patellar tendon-bone graft [SBR-BPTB], single-bundle reconstruction using a hamstring tendon graft [SBR-HST], single-tunnel double-bundle reconstruction using a hamstring tendon graft [STDBR-HST], anatomical single-tunnel reconstruction using a hamstring tendon graft [ASTR-HST], and a double-tunnel double-bundle reconstruction using a hamstring tendon graft [DBR-HST]) were systematically analyzed. The knee kinematics were determined under anterior tibial load (134 N) and simulated quadriceps load (400 N) at 0°, 15°, 30°, 60°, and 90° of flexion using a robotic testing system. Anterior joint stability under anterior tibial load was qualified as normal for ASTR-HST and DBR-HST and nearly normal for SBR-BPTB, SBR-HST, and STDBR-HST as per the International Knee Documentation Committee knee examination form categorization. The analysis of this study also demonstrated that SBR-BPTB, STDBR-HST, ASTR-HST, and DBR-HST restored the anterior joint stability to normal condition while the SBR-HST resulted in a nearly normal anterior joint stability under the action of simulated quadriceps load. The medial-lateral translations were restored to normal level by all the reconstructions. The internal tibial rotations under the simulated muscle load were over-constrained by all the reconstruction techniques, and more so by the DBR-HST. All five ACL reconstruction techniques could provide either normal or nearly normal anterior joint stability; however, the techniques over-constrained internal tibial rotation under the simulated quadriceps load.

Biomechanics of single-tunnel double-bundle anterior cruciate ligament reconstruction using fixation with a unique expandable interference screw

BACKGROUND

Single-tunnel double-bundle (STDB) anterior cruciate ligament (ACL) reconstruction can restore biomechanical function and anatomic structure, but existing methods of graft fixation are not adequate. The aims of this study are to examine knee biomechanics after STDB reconstruction using a unique expandable interference screw for fixation.

METHODS

The biomechanical parameters of six pairs of human cadaveric knee specimens were measured with the ACL intact, after ACL removal, and after STDB reconstruction using the interference screw or single-tunnel single-bundle (STSB) reconstruction. Anterior tibial translation under 134 N anterior tibial load in a neutral position as well as in 15° and 30° internal and external knee rotation and the internal tibial rotation angle under the rotatory load (5 N·m internal tibial rotation) were measured.

RESULTS

Anterior tibial translations at each degree of knee flexion in the STDB group were significantly less than in the STSB group (all, P<0.05). The internal rotation angles in the STSB group at five flexion angles were significantly higher than in the ACL intact group, whereas there were significantly less than those of the ACL absent group (P<0.05). Under rotatory loads in the neutral position, the tibial internal rotation angles of the STDB group were significantly lower than in the STSB group at all flexion angles (all, P<0.05).

CONCLUSIONS

STDB ACL reconstruction with the expandable interference screw provides better anteroposterior and rotational stability than STSB reconstruction.

CLINICAL RELEVANCE

The technique provides the advantages of double-bundle reconstruction using a single-tunnel technique.

A systematic review of single-bundle versus double-bundle anterior cruciate ligament reconstruction

INTRODUCTION

Double-bundle (DB) anterior cruciate ligament (ACL) reconstruction is becoming increasingly common. However, no definitive data on the superiority of DB reconstruction have been shown when compared with single-bundle (SB) ACL reconstruction.

SOURCES OF DATA

We performed a comprehensive search of PubMed, Medline, Cochrane, CINAHL and Embase databases using various combinations of keywords such as 'ACL', 'reconstruction', 'DB' and 'SB'. Only articles published in peer-reviewed journals were included in this systematic review.

AREAS OF AGREEMENT

Several new techniques are available for ACL reconstruction. DB ACL reconstruction could provide better outcome for patients in terms of closer restoration of normal knee biomechanics and improving the rotatory laxity of the knee.

AREAS OF CONTROVERSY

Data are lacking to allow definitive conclusions on the use of DB reconstruction techniques for routine management of patients with ACL tear.

GROWING POINTS

Given the limitations of the current studies, it is not possible to recommend systematic use of DB ACL reconstruction. Even though biomechanical results are encouraging, subjective patient evaluation is similar for SB and DB reconstruction.

AREAS TIMELY FOR DEVELOPING RESEARCH

Studies of higher levels of evidence, for instances large adequately powered randomized trials, should be conducted to bring new insight in this field. With the current evidence available, a simple SB ACL reconstruction is a suitable technique, and it should be not abandoned until stronger scientific evidence in favour of DB ACL reconstruction will be produced.

The concept of double bundle ACL simulation with a single bundle patellar tendon graft. A cadaveric feasibility study

Background

There is significant interest in the restoration of the double-bundle anatomy of the native ACL when performing ACL reconstruction. Possible techniques include those utilizing two separate grafts with independent tunnels and those that attempt to mimic this anatomy with a single graft and fewer tunnels. Many of the latter techniques require specific instrumentation and are technically challenging. We demonstrate that the double-bundle anatomy of the native ACL can theoretically be mimicked by a single-bundle reconstruction.

Methods

We performed single bundle ACL reconstruction with a bone-patellar tendon-bone (BTB) graft in two cadaveric knees. Both grafts were placed to mimic the native ACL footprints – one reconstruction was performed with rectangular bone blocks and oval tunnels and one was performed utilizing a standard BTB graft and round tunnels. Qualitative assessment of graft behavior was made as the knees were taken through a range of motion.

Results

The ACL graft was able to qualitatively mimic the behavior of the native ACL in both knees provided the bone blocks were correctly orientated.

Conclusions

ACL reconstruction with a single BTB graft can qualitatively mimic the behavior of the two bundles of the native ACL. The key to ensuring this behavior was noted to be appropriate orientation of the graft in the tunnels. Quantitative biomechanical investigations are necessary to evaluate the impact of graft orientation on function.

Extra-articular techniques in anterior cruciate ligament reconstruction: a literature review

This annotation considers the place of extra-articular reconstruction in the treatment of anterior cruciate ligament (ACL) deficiency. Extra-articular reconstruction has been employed over the last century to address ACL deficiency. However, the technique has not gained favour, primarily due to residual instability and the subsequent development of degenerative changes in the lateral compartment of the knee. Thus intra-articular reconstruction has become the technique of choice. However, intra-articular reconstruction does not restore normal knee kinematics. Some authors have recommended extra-articular reconstruction in conjunction with an intra-articular technique. The anatomy and biomechanics of the anterolateral structures of the knee remain largely undetermined. Further studies to establish the structure and function of the anterolateral structures may lead to more anatomical extra-articular reconstruction techniques that supplement intra-articular reconstruction. This might reduce residual pivot shift after an intra-articular reconstruction and thus improve the post-operative kinematics of the knee.

Biomechanical comparison of three anatomic ACL reconstructions in a porcine model

PURPOSE

Different tunnel configurations have been used for double-bundle (DB) anterior cruciate ligament (ACL) reconstruction. However, controversy still exists as to whether three-tunnel DB with double-femoral tunnels and single-tibial tunnel (2F-1T) or with single-femoral tunnel and double-tibial tunnels (1F-2T) better restores intact knee biomechanics than single-bundle (SB) ACL reconstruction. The purpose was to compare the knee kinematics and in situ force in the grafts among SB and two types of three-tunnel DB ACL reconstructions performed in an anatomic fashion.

METHODS

Twenty-four porcine knees were subjected to an 89-N anterior tibial load (simulated KT-1000 test) at 30°, 60°, and 90° of flexion and to a 4-Nm internal tibial torque and 7-Nm valgus torque (simulated pivot-shift test) at 30° and 60° of flexion. The resulting knee kinematics and in situ force in the ACL or replacement grafts were measured using a robotic system for (1) ACL-intact, (2) ACL-deficient, and (3) three ACL reconstructed knees: SB; DB 2F-1T; and DB 1F-2T.

RESULTS

During the simulated pivot-shift test, the DB grafts more closely restored the in situ force in the intact ACL at low flexion angle than the SB graft. There were no significant differences in knee kinematics between SB and DB ACL reconstruction. The DB 2F-1T reconstruction did not show a significant difference in knee kinematics or in situ force when compared to the DB 1F-2T technique.

CONCLUSION

The in situ force in the ACL is better restored with an anatomic three-tunnel DB reconstruction in response to the simulated pivot-shift test at low flexion angle when compared to an anatomic SB reconstruction. Both three-tunnel DB ACL reconstructions performed in an anatomic fashion had similar biomechanical behavior. As long as it is performed anatomically, DB ACL reconstruction could be better alternative than SB ACL reconstruction, no matter which three-tunnel procedure, 2F-1T or 1F-2T, is used.

"Anatomic" anterior cruciate ligament reconstruction: a systematic review of surgical techniques and reporting of surgical data

PURPOSE

The aim of this systematic review was to evaluate studies published on anatomic double-bundle anterior cruciate ligament (ACL) reconstruction.

METHODS

A systematic electronic search was performed by use of the Medline and Embase databases. Studies that were published from January 1995 to April 2009 were included. The selection criteria were studies that reported on a surgical technique for "anatomic double-bundle ACL reconstruction" on skeletally mature living human subjects and were written in English. Data collected and analyzed included a variety of surgical data. Tables were created to provide an overview of surgical techniques for anatomic ACL reconstruction.

RESULTS

Seventy-four studies were included in this review. Some surgical factors were adequately reported in the majority of the articles: visualizing the native ACL insertion sites, placing the tunnels in the footprint, graft type, and fixation method. However; ACL insertion site measurement, femoral intercondylar notch measurement, individualization of surgery, and intraoperative/postoperative imaging were poorly reported. The most variety was seen in knee flexion angle during femoral tunnel drilling and tensioning pattern of the grafts.

CONCLUSIONS

For most surgical data, there was a gross under-reporting of specific operative technique data. We believe that the details of an "anatomic" operative technique are crucial for the valid interpretations of the outcomes. Thus we encourage authors to report their surgical technique in a specific and standardized fashion.

Anatomic double-bundle anterior cruciate ligament reconstruction

Several double-bundle anterior cruciate ligament (ACL) reconstruction procedures were reported in the 1980s and 1990s. However, no significant differences were found in the clinical results between these double-bundle procedures and single-bundle procedures because the double-bundle procedures appeared to reconstruct only the anteromedial bundle with 2 bundles. In the early 2000s, we proposed a new concept of anatomic reconstruction of the anteromedial and posterolateral bundles, in which 4 independent tunnels were created through the center of each anatomic attachment of the 2 bundles. We called it "anatomic" double-bundle ACL reconstruction. Biomechanical studies have shown that the anatomic double-bundle ACL reconstruction can restore knee stability significantly more closely to the normal level than the conventional single-bundle reconstruction. Recent intraoperative measurement studies have shown that the clinically available anatomic double-bundle procedures can reconstruct knee stability significantly better and improve knee function close to the normal level at the time immediately after surgery compared with the conventional single-bundle procedures. However, the greatest criticism of the anatomic double-bundle reconstruction is whether its clinical results are better than the results of single-bundle reconstruction. To date (January 2010), 10 prospective comparative clinical trials (Level I or II) and 1 meta-analysis have been reported comparing single-bundle and anatomic double-bundle reconstructions using hamstring tendons. In 8 of the 10 studies, the anterior and/or rotatory stability of the knee was significantly better with the anatomic double-bundle ACL reconstruction than with the conventional single-bundle reconstruction. However, 1 original trial and the meta-analysis found that there were no differences in the results between the 2 types of reconstructions. Thus the utility of the anatomic double-bundle reconstruction has not yet been established. Our review does show how much evidence exists as to the benefits of double-bundle ACL reconstruction at present.

Rotational and translational laxity after computer-navigated single- and double-bundle anterior cruciate ligament reconstruction

Based on biomechanical cadaver studies, anatomic double-bundle reconstruction of the anterior cruciate ligament (ACL) was introduced to achieve better stability in the knee, particularly in respect of rotatory loads. Previously, the success of ACL reconstruction was believed to be mainly dependent on correct positioning of the graft, irrespective of the number of reconstructed bundles for which computer-assisted surgery was developed to avoid malpositioning of the tunnel. The aim of the present study is to compare rotational and translational stability after computer-navigated standard single-bundle, and anatomic double-bundle ACL reconstruction. The authors investigated 55 consecutive patients who had undergone the single-bundle or double-bundle ACL reconstruction procedure with the use of autogenous hamstring tendon grafts and EndoButton fixation, and the patients had been followed for a minimum period of 24 months. Intraoperative, anteroposterior and rotational laxity was measured with the computer navigation system, and compared between groups. Both surgical procedures significantly reduced anteroposterior displacement (AP) and internal rotation (IR) of the tibia compared to the pre-operative ACL-deficient knee (P < 0.05). No significant differences were registered between groups with regard to anteroposterior displacement of the tibia. A significantly greater reduction in internal rotation was noted in the double-bundle group (15.6 degrees) compared to the single-bundle group (7.1 degrees). The IKDC and Lysholm score were significantly higher in the double-bundle group. However, the results were excellent in both groups. The use of a computer-assisted ACL reconstruction, which is a highly accurate method of graft placement, could be useful for inexperienced surgeons to avoid malposition. Whether double-bundle ACL reconstruction, which was associated with improved rotational laxity and significantly better IKDC and Lysholm scores compared to the standard single-bundle ACL reconstruction procedure, provide an influence in terms of avoiding osteoarthritis or meniscus degeneration, long-term results of at least 5 years are needed.

Single-tunnel double-bundle anterior cruciate ligament reconstruction with anatomical placement of hamstring tendon graft: can it restore normal knee joint kinematics?

BACKGROUND

Anatomical reconstruction techniques that can restore normal joint kinematics without increasing surgical complications could potentially improve clinical outcomes and help manage anterior cruciate ligament injuries more efficiently.

HYPOTHESIS

Single-tunnel double-bundle anterior cruciate ligament reconstruction with anatomical placement of hamstring tendon graft can more closely restore normal knee anterior-posterior, medial-lateral, and internal-external kinematics than can conventional single-bundle anterior cruciate ligament reconstruction.

STUDY DESIGN

Controlled laboratory study.

METHODS

Kinematic responses after single-bundle anterior cruciate ligament reconstruction and single-tunnel double-bundle anterior cruciate ligament reconstruction with anatomical placement of hamstring tendon graft were compared with the intact knee in 9 fresh-frozen human cadaveric knee specimens using a robotic testing system. Kinematics of each knee were determined under an anterior tibial load (134 N), a simulated quadriceps load (400 N), and combined torques (10 N.m valgus and 5 N.m internal tibial torques) at 0 degrees , 15 degrees , 30 degrees , 60 degrees , and 90 degrees of flexion.

RESULTS

Anterior tibial translations were more closely restored to the intact knee level after single-tunnel double-bundle reconstruction with anatomical placement of hamstring tendon graft than with a single-bundle reconstruction under the 3 external loading conditions. Under simulated quadriceps load, the mean internal tibial rotations after both reconstructions were lower than that of the anterior cruciate ligament-intact knee with no significant differences between these 3 knee conditions at 0 degrees and 30 degrees of flexion (P > .05). The increased medial tibial shifts of the anterior cruciate ligament-deficient knees were restored to the intact level by both reconstruction techniques under the 3 external loading conditions.

CONCLUSION

Single-tunnel double-bundle anterior cruciate ligament reconstruction with anatomical placement of hamstring tendon graft can better restore the anterior knee stability compared with a conventional single-bundle reconstruction. Both reconstruction techniques are efficient in restoring the normal medial-lateral stability but overcorrect the internal tibial rotations.

CLINICAL RELEVANCE

Single-tunnel double-bundle anterior cruciate ligament reconstruction with anatomical placement of hamstring tendon graft could provide improved clinical outcomes over a conventional single-bundle reconstruction.

Biomechanical comparison of single-tunnel-double-bundle and single-bundle anterior cruciate ligament reconstructions

BACKGROUND

Anatomic double-bundle reconstruction has been thought to better simulate the anterior cruciate ligament anatomy. It is, however, a technically challenging procedure, associated with longer operation time and higher cost.

HYPOTHESIS

Double-bundle anterior cruciate ligament reconstruction using a single femoral and tibial tunnel can closely reproduce intact knee kinematics.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eight fresh-frozen human cadaveric knee specimens were tested using a robotic testing system to investigate the kinematic response of the knee joint under an anterior tibial load (130 N), simulated quadriceps load (400 N), and combined torques (5 N.m valgus and 5 N.m internal tibial torques) at 0 degrees, 15 degrees, 30 degrees, 60 degrees, and 90 degrees of flexion. Each knee was tested sequentially under 4 conditions: (1) anterior cruciate ligament intact, (2) anterior cruciate ligament deficient, (3) single-bundle anterior cruciate ligament reconstruction using quadrupled hamstring tendon, and (4) single-tunnel-double-bundle anterior cruciate ligament reconstruction using the same tunnels and quadrupled hamstring tendon graft as in the single-bundle anterior cruciate ligament reconstruction.

RESULTS

Single-tunnel-double-bundle anterior cruciate ligament reconstruction more closely restored the intact knee kinematics than single-bundle anterior cruciate ligament reconstruction at low flexion angles (< or =30 degrees ) under the anterior tibial load and simulated muscle load (P < .05). However, single-tunnel-double-bundle anterior cruciate ligament reconstruction overconstrained the knee joint at high flexion angles (> or =60 degrees ) under the anterior tibial load and at 0 degrees and 30 degrees of flexion under combined torques.

CONCLUSION

This double-bundle anterior cruciate ligament reconstruction using a single tunnel can better restore anterior tibial translations to the intact level compared with single-bundle anterior cruciate ligament reconstruction at low flexion angles, but it overconstrained the knee joint at high flexion angles.

CLINICAL RELEVANCE

This technique could be an alternative for both single-bundle and double-tunnel-double-bundle anterior cruciate ligament reconstructions to reproduce intact knee kinematics and native anterior cruciate ligament anatomy.

Biomechanical and tissue handling property comparison of decellularized and cryopreserved tibialis anterior tendons following extreme incubation and rehydration

Little is known regarding the biomechanical profiles and tissue handling properties of decellularized and cryopreserved human tibialis anterior tendons prepared as allografts for ACL reconstruction. This study compared allografts prepared using two extremes of the same cryoprotectant incubation and rehydration technique with a standardly prepared control group. Porcine tibiae with similar apparent BMD were randomly divided into three groups of ten specimens. Paired tendons were randomly divided into two experimental groups: Group 1 = 8 h incubation/15 min rehydration; Group 2 = 2 h incubation/1 h rehydration. Group 3 (control) consisted of ten standardly prepared tendons with 20 min rehydration. Tissue handling properties were graded during allograft preparation using a modified visual analog scale. Similar diameter allografts were fixed in matched diameter extraction drilled tibial tunnels with 35 mm long, 1 mm > tunnel diameter bioabsorbable interference screws. Potted constructs were mounted in a servo hydraulic device, pretensioned between 10-50 N at 0.1 Hz (10 cycles), and isometric pretensioned at 50 N for 1 min, prior to 500 submaximal loading cycles (50-250 N) at 0.5 Hz, and load to failure testing (20 mm/min). Constructs prepared under extreme conditions generally displayed comparable biomechanical properties to the control condition. Group 1 (8 h incubation/15 min rehydration)(-34 +/- 35 ms) and Group 2 (2 h incubation/1 h rehydration) (-22 +/- 38 ms) displayed smaller mean displacement-load peak phase timing differences over the initial ten cycles compared to Group 3 (control)(-42 +/- 49 ms), P = 0.004, suggesting greater relative construct stiffness. Group 1 (8 h incubation/15 min rehydration) (234.9 +/- 34 N/mm) and Group 2 (2 h incubation/1 h rehydration)(231.3 +/- 43 N/mm) displayed lower construct stiffness during load to failure testing than Group 3 (control)(284.5 +/- 25.2 N/mm), P = 0.003. Group 1 (8 h incubation/15 min rehydration) differed from Group 2 (2 h incubation/1 h rehydration) and Group 3 (control) for perceived tensile stiffness (2.4 +/- 2.0 vs. 7.0 +/- 0.5 and 7.9 +/- 0.3, respectively), compressive resilience (1.7 +/- 0.8 vs. 5.9 +/- 1.0 and 7.8 +/- 0.4, respectively), handling ease (2.8 +/- 1.0 vs. 6.5 +/- 0.5 and 7.0 +/- 0.7, respectively), color (2.6 +/- 0.8 vs. 4.7 +/- 0.7 and 5.1 +/- 0.3, respectively) and texture (4.0 +/- 0.8 vs. 6.2 +/- 0.8 and 6.8 +/- 0.8, respectively) (P < 0.0001). Group 2 (2 h incubation/1 h rehydration)(6.0 +/- 0.7 and 5.9 +/- 1.0, respectively) also differed from Group 3 (control)(6.8 +/- 0.8 and 7.8 +/- 0.4, respectively) for general "feel" and compressive resilience (P < 0.0001). Tensile stiffness and compressive resilience displayed moderate and weak relationships, respectively with displacement during submaximal cyclic loading (r2 = 0.78 and 0.58, respectively), stiffness (r2 = 0.33 and 0.44, respectively) and load at failure (r2 = 0.59 and 0.37, respectively) for Group 3 (control), but not for experimental Group 1 (8 h incubation/15 min rehydration) or Group 2 (2 h incubation/1 h rehydration). Knee surgeons should be aware that soft tissue tendon decellularization and cryopreservation may change the biomechanical stiffness, tissue handling properties, and relationships between these variables compared to standardly prepared allograft tissue.

Trantibial anterior cruciate ligament double bundle reconstruction technique: two tibial bundle in one tibial tunnel

The anterior cruciate ligament (ACL) consists of two functional bundles that behave independently throughout the range of knee motion. Many two-bundle reconstruction techniques have been introduced to restore the function of the two bundles of the ACL. Generally, two femoral and two tibial tunnels are made during the surgery for a two-bundle ACL reconstruction. However, the procedure is technically demanding and time consuming. This paper describes one-tibial-two-femoral ACL double bundle reconstruction technique with a sextuple-stranded hamstring autograft. The anteromedial femoral tunnel is made using transtibial drilling technique and posterolateral femoral tunnel is made using outside-in technique. The two bundles in a single tibial tunnel are separated using biodegradable interference screw. Stable and adequate femoral fixation of the two bundles with a transtibial fixation and bioabsorbable screw can be obtained. This technique is relatively simple, and replicates the anatomy and differential behavior of the two native bundles of ACL more effectively.

Systematic review of single-bundle anterior cruciate ligament reconstruction outcomes: a baseline assessment for consideration of double-bundle techniques

BACKGROUND

There is increasing interest in comparing the efficacy of single-bundle versus double-bundle anterior cruciate ligament reconstruction. Challenging this comparison, however, has been the lack of an established consensus on the success of single-bundle reconstruction.

HYPOTHESIS

The current outcomes of single-bundle reconstruction can be clarified from a large unbiased body of evidence for future comparisons with double-bundle reconstructions.

STUDY DESIGN

Systematic review.

METHODS

A systematic review of 11 randomized, controlled trials comparing patellar tendon and hamstring tendon grafting is reported. The respective outcomes of each group were combined to assist the orthopaedic surgeon in assessing the current success of single-bundle reconstruction. The primary factors assessed were tibial subluxation and side-to-side differences in laxity. Secondary outcomes included concomitant injuries and treatments, complications, graft failure, range of motion, and radiographic evidence of degenerative changes.

RESULTS

In this review of 1024 single-bundle anterior cruciate ligament reconstructions, 495 concomitant meniscal tears, 95 chondral injuries, and 2 posterior cruciate ligament tears were noted. The complication rate was 6%, and graft failure 4%. Reported pivot-shift test results were negative in 81% of cases; reported Lachman tests were negative in 59% cases; and KT-1000 arthrometer side-to-side differences were <or= 5 mm in 86% of cases. Flexion and extension deficits were reported in 9 of 11 studies through mean range of motion or deficit ranges. Radiographic changes of articular surface abnormalities were observed in 7% of the knees at follow-up investigation.

CONCLUSION

Systematic review of a significant body of unbiased outcome data on single-bundle anterior cruciate ligament reconstruction demonstrates it to be a safe, consistent surgical procedure affording reliable results.

CLINICAL RELEVANCE

These results may be used to assist orthopaedic surgeons in evaluating the benefit and practicality of pursuing new anterior cruciate ligament reconstruction techniques over standard single-bundle anterior cruciate ligament reconstruction.

Double-bundle arthroscopic reconstruction of the anterior cruciate ligament

There is a trend towards the use of double-bundle techniques for the reconstruction of the anterior cruciate ligament. This has not been substantiated scientifically. The functional outcome of these techniques is equivalent to that of single-bundle methods. The main advantage of a double-bundle rather than a single-bundle reconstruction should be a better rotational stability, but the validity and accuracy of systems for the measurement of rotational stability have not been confirmed.

Despite the enthusiasm of surgeons for the double-bundle technique, reconstruction with a single-bundle should remain the standard method for managing deficiency of the anterior cruciate ligament until strong evidence in favour of the use of the double-bundle method is available.

Femoral tunnel placement in single-bundle anterior cruciate ligament reconstruction: a cadaveric study relating transtibial lateralized femoral tunnel position to the anteromedial and posterolateral bundle femoral origins of the anterior cruciate ligament

BACKGROUND

There is controversy regarding the necessity of reconstructing both the posterolateral and anteromedial bundles of the anterior cruciate ligament.

HYPOTHESIS

A laterally oriented transtibial drilled femoral tunnel replaces portions of the femoral footprints of the anteromedial and posterolateral bundles of the anterior cruciate ligament.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Footprints of the anteromedial and posterolateral bundles of the anterior cruciate ligament were preserved on 7 matched pairs (5 female, 2 male) of fresh-frozen human cadaveric femurs (14 femurs total). Each femur was anatomically oriented and secured in a custom size-appropriate, side-matched replica tibia model to simulate transtibial retrograde drilling of a 10-mm femoral tunnel in each specimen. The relationship of the tunnel relative to footprints of both bundles of the anterior cruciate ligament was recorded using a Microscribe MX digitizer. The angle of the femoral tunnel relative to the vertical 12-o'clock position was recorded for all 14 specimens; only 10 specimens were used for footprint measurements.

RESULTS

On average, the 10-mm femoral tunnel overlapped 50% of the anteromedial bundle (range, 2%-83%) and 51% of the posterolateral bundle (range, 16%-97%). The footprint of the anteromedial bundle occupied 32% (range, 3%-49%) of the area of the tunnel; the footprint of the posterolateral bundle contributed 26% (range, 7%-41%). The remainder of the area of the 10-mm tunnel did not overlap with the anterior cruciate ligament footprint. The mean absolute angle of the femoral tunnel as measured directly on the specimen was 48 degrees (range, 42 degrees-53 degrees) from vertical, corresponding to approximately a 10:30 clock face position on a right knee.

CONCLUSION

Anterior cruciate ligament reconstruction using a laterally oriented transtibial drilled femoral tunnel incorporates portions of the anteromedial and posterolateral bundle origins of the native anterior cruciate ligament.

CLINICAL RELEVANCE

A laterally oriented transtibial drilled femoral tunnel placed at the 10:30 position (1:30 for left knees) reconstructs portions of the anteromedial and posterolateral bundles of the anterior cruciate ligament.

Hybrid anterior cruciate ligament reconstruction: introduction of a new technique for anatomic anterior cruciate ligament reconstruction

Recently, anatomic or double-bundle reconstruction of the anterior cruciate ligament (ACL) has been presented in an effort to more accurately restore the native anatomy. These techniques create 2 tunnels in both the femur and tibia to reproduce the bundles of the ACL. However, the increased number of tunnels, particularly on the femoral side, has raised some concerns among authors and surgeons. We describe a technique to reconstruct the 2 distinct bundles of the ACL by using a single femoral tunnel and 2 tibial tunnels, the "hybrid" ACL reconstruction. The femoral tunnel is drilled through an anteromedial arthroscopy portal, which allows placement in a more anatomic position. Fixation in the femur is achieved with a novel device that separates a soft-tissue graft into 2 independently functioning bundles. Once fixed in the femur, the anteromedial and posterolateral bundles of the graft are passed through respective tunnels at the anatomic footprint on the tibia. These bundles are independently tensioned, which creates a reconconstruction that is similar to the native ACL. The technique presented provides surgeons with an alternative to other double-bundle techniques involving 4 tunnels.

Second-look arthroscopic evaluations of anatomic double-bundle anterior cruciate ligament reconstruction: relation with postoperative knee stability

PURPOSE

The purpose of this study was to test the hypothesis that both the anteromedial and posterolateral bundles may be clearly visible after anatomic double-bundle reconstruction, as well as that a strong relation may exist between the appearance of the 2 bundles and the clinical evaluation.

METHODS

A prospective study was performed based on 178 consecutive patients who underwent anatomic double-bundle anterior cruciate ligament reconstruction with 2 hamstring tendon autografts in the unilateral knee. To develop arthroscopic diagnostic criteria, clinical evaluations were carried out at 1 to 2 years concerning the anterior laxity, the pivot-shift test, the Lysholm knee score, and the International Knee Documentation Committee evaluation, and 136 of the 178 patients underwent second-look arthroscopy shortly before or after the clinical examinations that are the basis of this study. The focus of the second-look arthroscopy was on graft thickness, apparent tension, and synovium coverage of the bundle.

RESULTS

Second-look arthroscopy showed that the anteromedial bundle was evaluated as excellent in 79.5% of the knees, fair in 16.7%, and poor in 3.8% and the posterolateral bundle was evaluated as excellent in 75.8%, fair in 21.2%, and poor in 3.0%. There was a significant difference in the anterior laxity and the pivot-shift test among the arthroscopically observed categories. Between the knees with second-look arthroscopy and those without it, there were no significant differences in all clinical evaluations.

CONCLUSIONS

Both the anteromedial and posterolateral bundles were clearly visible after the anatomic double-bundle anterior cruciate ligament reconstruction at 1 to 2 years after surgery. There was a significant difference in the anterior laxity and pivot-shift test in patients in category I, which comprised those who had excellent anteromedial and posterolateral bundles, compared with those in category II or III, which comprised those in whom either 1 or both of the bundles was scored as less than excellent.

LEVEL OF EVIDENCE

Level II, development of diagnostic criteria on the basis of consecutive patients with universally applied reference gold standard.

Strain pattern comparison of double- and single-bundle anterior cruciate ligament reconstruction techniques with the native anterior cruciate ligament

PURPOSE

The purpose of this study was to dynamically assess the native strain patterns of the anteromedial bundle (AMB) and posterolateral bundle (PLB) of the anterior cruciate ligament (ACL) and compare these findings with graft bundle strain patterns after double-bundle (DB) ACL reconstruction with tibial fixation under 40 N of tension at 75 degrees knee flexion (AMB) and under 20 N of tension at 20 degrees knee flexion (PLB) and after single-bundle (SB) reconstruction with tibial fixation under 40 N of tension at 20 degrees knee flexion.

METHODS

The mean strain pattern of the AMB and PLB of the native ACL of 4 cadaveric knees was measured via differential variable reluctance transducers and 2-dimensional kinematic analysis during passive manual knee flexion-extension under a constant axial compression load. Measurements were repeated after DB and SB ACL reconstruction. Celeration line assessments with a split-middle technique were performed to quantify percent strain/knee flexion-extension angle change at reciprocating bundle function transition points.

RESULTS

The DB ACL reconstruction technique displayed reciprocating AMB and PLB strain patterns that more closely replicated those of the native ACL. The SB ACL reconstruction technique tended to replicate AMB strain patterns, suggesting poor bundle function differentiation.

CONCLUSIONS

The DB ACL reconstruction with differential AMB and PLB tensioning more closely replicated native ACL strain patterns than the SB ACL reconstruction. The SB ACL reconstruction that we used closely simulated native ACL AMB strain patterns; however, PLB function was not restored.

CLINICAL RELEVANCE

The DB ACL reconstruction more closely replicated the AMB and PLB strain patterns of the native ACL.

Double-bundle anterior cruciate ligament reconstruction using two different suspensory femoral fixation: a technical note

We describe a novel double-bundle reconstruction method for ACL deficient knee. Grafts are tibialis allograft for AMB (anteromedial bundle) and semitendinosus autograft for PLB (posterolateral bundle). Femoral fixations are done by Bio-TransFix for AMB and EndoButton for PLB. Tibial fixations are done by Bio-interference screw for AMB at 60-70 degrees knee flexion and secure the PLB and remnant AMB graft simultaneously onto anteromedial aspect of tibia at 10-20 degrees knee flexion with spiked washer and screw. With our technique, graft lengths are not restricted and we provide strong femoral and tibial fixation if it is compared with previous techniques.

Radiologic evaluation of femoral and tibial tunnels created with the transtibial tunnel technique for anatomic double-bundle anterior cruciate ligament reconstruction

PURPOSE

The purpose of this study was to clarify femoral and tibial tunnel angles in anatomic double-bundle anterior cruciate ligament (ACL) reconstruction.

METHODS

A prospective study was performed in 50 consecutive patients who underwent anatomic double-bundle ACL reconstruction via hamstring tendon grafts for chronic ACL deficiency in the unilateral knee. For this procedure, 2 hamstring tendon grafts were secured with EndoButtons (Smith & Nephew Endoscopy, Andover, MA) on the femur and with 2 staples on the tibia. Each patient underwent radiologic examination 1 year after surgery.

RESULTS

The tibial tunnel angles of the posterolateral bundle averaged 40.7 degrees in the anteroposterior view and 35.4 degrees in the lateral view. The tibial tunnel angles of the anteromedial bundle averaged 15.6 degrees in the anteroposterior view and 41.4 degrees in the lateral view. The femoral tunnel angles of the posterolateral bundle averaged 44.0 degrees in the anteroposterior view and 52.0 degrees in the lateral view. The femoral tunnel angles of the anteromedial bundle averaged 18.0 degrees in the anteroposterior view and 49.8 degrees in the lateral view.

CONCLUSIONS

The given data will be useful for surgeons to evaluate the tunnel positions and standardization postoperatively in anatomic double-bundle reconstruction.

LEVEL OF EVIDENCE

Level II, development of diagnostic criteria on the basis of consecutive patients with universally applied reference gold standard.

Anatomic double bundle ACL reconstruction: a literature review

With the abundance of anatomic double bundle ACL reconstruction techniques that currently exist and limited patient outcome data, one has to ask whether or not they should be used and if so, which one, and what is the learning curve for the average knee surgeon to become competent with the technique that they select? The purpose of this literature review is to summarize existing anatomic double bundle ACL reconstruction surgical and rehabilitation techniques and the clinical and biomechanical study evidence that currently exists. In choosing to perform anatomic double bundle ACL reconstruction we suggest that the knee surgeon should look for evidence of: (1) control of the pivot shift phenomenon, (2) improved transverse plane rotatory knee control during the performance of sports type movements, (3) a decreased likelihood of revision procedures either for ACL reconstruction or for treatment of associated primary or recurrent meniscal injuries, (4) improved patient self-reports of perceived function, satisfaction, and quality of life, and (5) radiographic evidence of a lower incidence and/or magnitude of osteoarthritic changes compared to conventional single bundle ACL reconstruction.

Double-bundle anterior cruciate ligament reconstruction: four versus eight strands of hamstring tendon graft

PURPOSE

The purpose of this study was to compare the clinical results of a double-bundle anterior cruciate ligament (ACL) reconstruction with 4 strands versus 8 strands of hamstring tendon graft.

METHODS

Seventy-six patients with chronic ACL rupture were randomly separated into two groups for double-bundle ACL reconstruction. In the 4-strand hamstring graft (4SHG) group, the semitendinosus tendon was used to make two 2-stranded hamstring tendon grafts, whereas in the 8-strand hamstring graft (8SHG) group, the semitendinosus tendon was used to make one 4SHG and the gracilis tendon was used to make the other 4SHG. The 4SHG group comprised 33 patients and the 8SHG group comprised 35 patients, with a minimum follow-up of 2 years. International Knee Documentation Committee (IKDC) and Lysholm scales were used to evaluate the clinical results.

RESULTS

In the 4SHG group the side-to-side difference was less than 3 mm in 26 patients (78.8%), 3 to 5 mm in 4 patients (12.1%), and 6 to 10 mm in 3 patients (9.0%), with a mean value of 2.8 +/- 0.5 mm; the pivot-shift test was negative in 29 patients (89.9%) and positive in 4 (12.1%). In the 8SHG group the side-to-side difference was less than 3 mm in 32 patients (91.4%), 3 to 5 mm in 2 patients (5.7%), and 6 mm in 1 patient (2.9%) (P = .004), with a mean value of 1.3 +/- 0.4 mm (P = .0003); the pivot-shift test was negative in 34 patients (97.1%) and positive in 1 (2.9%). According to the IKDC scale, 29 patients (87.9%) in the 4SHG group and 33 patients (94.3%) in the 8SHG group had a grade of normal or nearly normal. In the 4SHG and 8SHG groups the mean IKDC subjective knee evaluation results were 86.4 +/- 4.2 and 96.3 +/- 2.8 (P = .0007), respectively, and the mean Lysholm scores were 89.6 +/- 3.7 and 96.5 +/- 2.9 (P = .0006), respectively.

CONCLUSIONS

On the basis of KT-1000 examination (MEDmetric, San Diego, CA) and clinical measures, double-bundle ACL reconstruction with 8SHG yields significantly better results than double-bundle ACL reconstruction with 4SHG, with a mean side-to-side difference in anterior knee laxity of 1.3 +/- 0.4 mm versus 2.8 +/- 0.5 mm (P = .0003), IKDC subjective result of 96.3 +/- 2.8 versus 86.4 +/- 4.2 (P = .0007), and Lysholm score of 96.5 +/- 2.9 versus 89.6 +/- 3.7 (P = .0006).

LEVEL OF EVIDENCE

Level II, lesser-quality randomized controlled trial.

The double-bundle technique for anterior cruciate ligament reconstruction: a systematic overview

In traditional anterior cruciate ligament reconstruction, there is a subset of patients complaining of knee instability, especially rotational instability, and athletes not able to return to their preinjury level of sports activity. Currently, controversy exists over the usefulness of the double bundle technique (DBT) in addressing these problems. In order to evaluate the DBT, we completed a literature review from 1969 to February 2006 focusing on anatomy, magnetic resonance imaging, graft incorporation, biomechanics, kinematics, surgical techniques, complications and outcome. The DBT is not a standardized technique, which makes it difficult to compare results. Cadaver studies have proven biomechanical advantages with respect to ap-stability, but assessing the rotational stability remains difficult. There is a lack of available outcome studies with sufficient follow-up to demonstrate the potential advantages of DBT. The theoretical advantages of DBT require careful evaluation with outcome, biomechanical and kinematic studies. In addition, studies are needed to address issues such as graft incorporation and complications. An advantage offered by DBT is the possibility to identify rupture patterns that can lead to surgical preservation of an intact and augmentation of an injured bundle. The approach of augmentating a single bundle technique reconstruction with adequate anterior-posterior but poor rotational stability is promising.

Augmentation technique with semitendinosus and gracilis tendons in chronic partial lesions of the ACL: clinical and arthrometric analysis

Most of the techniques described in the literature for the repair of chronic partial ACL tears, don't spare the intact portion of the ligament. The aim of this study was to perform a prospective analysis of the results of augmentation surgery using gracilis and semitendinosus tendons to treat partial sub-acute lesions of the ACL. This technique involves an "over the top" femoral passage, which enables salvage and strengthening of the intact portion of the ACL. The study included 47 patients treated consecutively at our institute from 1993 to 1998, with a mean injury-surgery interval of 18 weeks (range 12-36). The patients were followed up by clinical and instrumental assessment criteria at 3 months, 1 and 5 years after surgery. Clinical assessment was performed using the IKDC form. Subjective and functional parameters were assessed by the Tegner activity scale. Instrumental evaluation was done using the KT-2000 instrument: the 30-pound passive test and the manual maximum displacement test were performed. We obtained good or excellent results in 95.7% of cases. No recurrences in ligamentous laxity were observed. We believe that the described technique has the advantage of being compatible with ACL anatomy, and enables very rapid functional recovery.