Prospective clinical comparisons of anatomic double-bundle versus single-bundle anterior cruciate ligament reconstruction procedures in 328 consecutive patients

Is double-bundle anterior cruciate ligament reconstruction superior to single-bundle? A comprehensive systematic review

PURPOSE

To describe current evidence on single- and double-bundle anterior cruciate ligament (ACL) reconstruction, in terms of differences in knee kinematics, functional outcomes, patient-reported outcomes and graft failures.

METHODS

An electronic search was made using PubMed (MEDLINE), EMBASE and Cochrane Library. Studies published from January 1995 to August 2011 were included, and an updated search was made in PubMed in July 2012. Therapeutic studies, level of evidence I-III, for isolated primary ACL tears written in English comparing single- and double-bundle reconstruction reporting clinical outcome were included. Quality appraisal based on Cochrane Collaboration's tool for assessing risk of bias was performed.

RESULTS

Of 7,154 potentially eligible studies, 60 papers were included (25 randomised controlled trials, 21 prospective comparative studies, 14 retrospective comparative studies), comprising 4,146 patients (2,072 single-bundle, 2,074 double-bundle). Minor differences were found between study types. An analysis of graft failures revealed fewer re-ruptures in double-bundle reconstruction than single-bundle, 19 and 44, respectively. Up to 45 % of the studies reported a superior outcome in double-bundle reconstruction in terms of antero-posterior laxity, measured with the Lachman, anterior drawer, KT-1000/2000 and navigation. Measurements of rotatory laxity revealed superior results in double-bundle reconstruction measured with pivot shift and navigation in 18/42 (8/15 anatomically reconstructed) and 9/20 studies, respectively. Patient-reported outcome measures and functional outcomes did not differ to a large extent; however, differences when identified were almost exclusively in favour of double-bundle reconstruction.

CONCLUSION

Based on current evidence, double-bundle reconstruction appears to have fewer re-ruptures and less antero-posterior and rotatory laxity. Furthermore, no differences were found in short-term patient-reported outcome measures or objective findings. However, detailed statistical analyses of the included studies divided into homogeneous groups are needed to avoid reporting bias and to confirm any statistical difference.

Balance ability and proprioception after single-bundle, single-bundle augmentation, and double-bundle ACL reconstruction

Purpose. The present study sought to determine the influences of single-bundle (SB), single-bundle augmentation (SBA), and double-bundle (DB) reconstructions on balance ability and proprioceptive function. Methods. 67 patients who underwent a single- or double-bundle ACL reconstruction or a SBA using multistranded autologous hamstring tendons were included in this study with a 1-year follow-up. Body sway and knee kinesthesia (using the threshold to detect passive motion test (TTDPM)) were measured to indicate balance ability and proprioceptive function, respectively. Additionally, within-subject differences in anterior-posterior stability of the tibia and lower extremity muscle strength were evaluated before and after surgery. Results. At 6 and 12 months after surgery, DB reconstruction resulted in better balance and proprioceptive function than SB reconstruction (P < 0.05). Although no significant difference was observed in balance ability or proprioceptive function between the SBA and DB reconstructions, knee stability was significantly better with SBA and DB reconstructions than SB reconstruction (P < 0.05). No significant differences were found in quadriceps and hamstrings strength among the three reconstruction techniques. Conclusions. Our findings consider that joint stability, proprioceptive function, and balance ability were superior with SBA and DB reconstructions compared to SB reconstruction at 6 and 12 months after surgery.

Comparison of the Modified Transtibial Technique, Anteromedial Portal Technique and Outside-in Technique in ACL Reconstruction

Purpose

To compare clinical and radiographic results of anterior cruciate ligament (ACL) reconstruction using modified transtibial technique (mTT), anteromedial (AM) portal technique and outside-in (OI) technique.

Materials and Methods

From March 2007 to December 2012, ACL reconstruction was performed using the mTT, AM portal technique and OI technique in 20 patients each. Anteroposterior and rotational stability were assessed using the GNRB arthrometer and pivot-shift test. Femoral tunnel obliquity was measured on the anteroposterior and lateral radiographs.

Results

Tegner score, Lysholm score, International Knee Documentation Committee score, pivot-shift test were improved at final follow-up in all three groups. However, statistical difference was not shown. Side-to-side difference in GNRB arthrometer was average of 1.4 mm, 1.0 mm and 0.9 mm in mTT, AM and OI group, showing the signicant difference between mTT and AM/OI groups (p<0.001). The mean femoral tunnel obliquity was 56.4° in the mTT group, 39.4° in the AM group and 33.6° in the OI group, showing significant intergroup difference (p<0.001). It showed the significant difference among three groups (p<0.001).

Conclusions

Clinical results were improved in all three groups. Femoral tunnel obliquity in AM and OI were more horizontal on the coronal plane. They are thought to have more benefits in oblique positioning of the grafted ACL in rotational stability; however, there was no significant difference among three techniques in pivot-shift test to assess the rotational stability in this study.

Clinical and three-dimensional computed tomographic comparison between ACL transportal versus ACL transtibial single-bundle reconstructions with hamstrings

BACKGROUND

Anterior cruciate ligament (ACL) reconstruction using a single-bundle transtibial technique can achieve good or excellent results in more than 90% of patients, but anatomical and biomechanical studies have questioned its ability to restore knee function. The purpose of this study was to evaluate clinical and tomographic results (patient satisfaction, knee function, and tunnel location) of patients who underwent transportal or transtibial single-bundle ACL reconstruction.

METHODS

Seventy-one patients with ACL tears were included. Forty-one patients were treated by the single-bundle transportal technique and 30 patients were treated by the single-bundle transtibial technique. Clinical and tomographic data were analyzed in both groups.

RESULTS

After a minimum of 2-year period, the transportal group showed more patients with normal clinical tests than the transtibial group (Lachman [p=0.037], pivot shift [0.00], anterior drawer [0.002]; and arthrometer [0.002] tests). Regarding CT evaluation, transportal and transtibial groups obtained the following femoral central tunnel location (mean [SD]), as percentage: 30 (6.5) and 4.2 (6.4) in high-low axis; and 30.9 (5.9) and 33.2 (4.6) in the deep-shallow axis. Values in the tibial side were, respectively: 38 (6.5) and 46.0 (6.8) in the anterior-posterior axis; and 47.2 (2.5) and 46.9 (2.1) in the medial-lateral axis.

CONCLUSION

CT findings showed that the transportal single-bundle technique positions the ACL tunnel closer to the native ACL footprint in both femur and tibia compared with the transtibial single-bundle technique. Moreover, mild asymptomatic instability and extension deficit were observed more often in the transtibial group.

"Anatomic" single-bundle anterior cruciate ligament reconstruction reduces both anterior translation and internal rotation during the pivot shift

BACKGROUND

The ability of single-bundle anterior cruciate ligament (ACL) reconstruction to restore rotational control has been questioned by proponents of the double-bundle technique. The term anatomic positioning has become popularized in recognition of the incorrect positioning sometimes used in the past, which may have contributed to the lack of rotation control. The pivot-shift test remains the most clinically useful measure of ACL deficiency, and it is now possible to measure it both accurately and objectively using computer navigation.

HYPOTHESIS

Single-bundle ACL reconstruction will reduce anterior translation and internal rotation of the tibia during the pivot-shift test when compared with the contralateral uninjured knee.

STUDY DESIGN

Descriptive laboratory study.

METHODS

A total of 20 patients with an acute isolated ACL rupture underwent reconstruction with a single-bundle autologous hamstring graft. Computer navigation was used intraoperatively to plot the pivot shift before and after reconstruction. The opposite uninjured knee was used as a control. Statistical analysis was used to compare the pivot shifts before and after surgery.

RESULTS

Single-bundle ACL reconstruction produced a significant reduction in anterior translation, from a mean ± SD of 17.4 ± 3.80 mm to 6.4 ± 1.95 mm (P < .001), as well as in internal rotation, from 22.9° ± 5.91° to 7.5° ± 2.96° (P < .001). The anterior translation in the reconstructed knees was similar to the control knees, 6.4 ± 1.95 mm versus 5.6 ± 1.23 mm (P < .148), while the internal rotation was significantly less in the reconstructed knees, 7.5° ± 2.96° versus 11.9° ± 3.36° (P < .05). The values for the coupled movements were used to calculate the length of the radius of curvature, about which the tibia rotates relative to the femur, during the pivot shift. In the control knees, the mean value was 28.9 ± 8.21 mm, while there was extreme variability in the operated knee both before and after surgery.

CONCLUSION

It is possible to reduce both anterior translation and internal rotation, which occur during the pivot-shift test in the ACL-deficient knee, using single-bundle ACL reconstruction, when measured at the time of surgery. However, normal motion is not fully restored.

Effect of femoral tunnel position on graft tension curves and knee stability in anatomic double-bundle anterior cruciate ligament reconstruction

PURPOSE

To evaluate the effect of the femoral tunnel position of the anteromedial bundle (AMB) and the posterolateral bundle (PLB) on the graft tension curves and knee stability in anatomic double-bundle anterior cruciate ligament (ACL) reconstruction.

METHODS

Forty-five patients who underwent anatomic double-bundle ACL reconstruction were included. AMB and PLB were provisionally fixed to a graft tensioning system in the following settings during surgery: (1) AMB at 20° and PLB at 0° (A20P0), (2) AMB at 20° and PLB at 20° (A20P20), and (3) AMB at 20° and PLB at 45° (A20P45). Bundle tension was recorded during knee flexion-extension. A pivot shift test was also evaluated. Femoral tunnel positions of the AMB and PLB were then assessed by three-dimensional computed tomography, and the correlation between femoral tunnel position and tension change pattern or residual pivot shift was evaluated.

RESULTS

The depth of the PLB tunnel position was correlated with the extent of tension reduction in the PLB between 0° and 30° irrespective of graft fixation settings, while neither the AMB tunnel position nor the height of the PLB tunnel position affected the tension change pattern. Ten cases showed grade 1 pivot shift only in the A20P0 setting. The PLB tunnel position in the pivot shift-positive cases was significantly deeper than that in the pivot shift-negative cases (27.5 ± 6.2 and 34.1 ± 5.5%, respectively, P = 0.002).

CONCLUSIONS

In anatomic double-bundle reconstruction, deeper PLB tunnel position was correlated with the larger tension reduction in the PLB between 0° and 30°. Fixation of the AMB at 20° and the PLB at 0° resulted in residual pivot shift phenomenon in 10/45 cases, and the PLB tunnel position in the pivot shift-positive cases was significantly deeper than that in the pivot shift-negative cases. In anatomic double-bundle reconstruction, the placement of PLB femoral tunnel must not be too deep, as it might lead to significant tension reduction in the PLB near extension and thus insufficient tension in the PLB, resulting in residual pivot shift phenomenon.

LEVEL OF EVIDENCE

IV.

Factors influencing graft impingement on the wall of the intercondylar notch after anatomic double-bundle anterior cruciate ligament reconstruction

BACKGROUND

Anatomic placement of the bone tunnel reportedly reduces impingement of the graft with the intercondylar roof, but as a trade-off, the risk of impingement with the lateral wall of the intercondylar notch would increase instead in anatomic double-bundle anterior cruciate ligament (ACL) reconstruction.

PURPOSE

The 2 grafts for the anteromedial bundle (AMB) and posterolateral bundle (PLB) were separately analyzed for the frequency of and risk factors for graft impingement on the wall of the intercondylar notch.

STUDY DESIGN

Case control study; Level of evidence, 3.

METHODS

A total of 51 patients (53 knees) who underwent primary anatomic double-bundle ACL reconstruction were enrolled. Based on the graft orientation plane reconstructed with 3-dimensional imaging software, graft-wall impingement was defined as overlap between the lateral wall of the notch and the line connecting each center of the intra-articular apertures of the femoral and tibial bone tunnels. The rate of wall impingement was assessed for each bundle. Parameters for bone tunnel positioning in the femur and tibia, notch width index, and knee joint rotation angle were compared between patients with and without wall impingement. The most important risk factors for wall impingement were assessed by logistic regression analysis.

RESULTS

Wall impingement for the AMB was observed in 22 knees (42%), whereas no patients exhibited wall impingement for the PLB. Regarding femoral bone tunnel positioning according to the quadrant method, the AMB bone tunnel was placed significantly higher in impingement-positive patients than in impingement-negative patients (P = .03). Regarding tibial tunnel positioning, the tunnel was placed significantly more anteriorly (P = .02) and laterally (P = .02) in the impingement-positive group than in the impingement-negative group. Bone tunnels positioned 48% to 50% from the medial border of the tibia demonstrated a 100% incidence of wall impingement. Based on logistic regression analysis, lateral deviation of the AMB tibial bone tunnel was significantly associated with wall impingement (odds ratio, 1.403; P = .048).

CONCLUSION

The tibial bone tunnel position in the coronal orientation was most likely associated with wall impingement. Considering that tibial bone tunnels are generally created with the knee in 90° of flexion and move laterally as the knee extends because of screw-home movement, the AMB bone tunnel for the tibia should be positioned as medially as possible within its footprint to minimize the risk of wall impingement after anatomic double-bundle ACL reconstruction.

Clinical outcome of anatomic double-bundle ACL reconstruction and 3D CT model-based validation of femoral socket aperture position

PURPOSE

The purpose of this study was to evaluate the clinical results of anatomic double-bundle (DB) anterior cruciate ligament (ACL) reconstruction in which anatomic position of femoral socket apertures was validated using three-dimensional (3D) computed tomography (CT) modelling.

METHODS

Anatomic DB ACL reconstructions with hamstring autografts were performed in 34 patients. Two femoral sockets were created through a far anteromedial (AM) portal behind the lateral intercondylar ridge with the assistance of intraoperative 3D fluoroscopic navigation. Femoral tunnel aperture positioning was investigated postoperatively using 3D CT images in all patients. Clinical results were also evaluated subjectively and objectively at least up to 2 years.

RESULTS

Measurement of the AM and the posterolateral (PL) femoral socket locations on the 3D CT images using the quadrant method showed that the centre of the AM socket aperture was located at a depth of 21.0 ± 4.1% and a height of 30.5 ± 9.3% and that of the PL socket aperture was located at a depth of 31.3 ± 5.8% and a height of 57.2 ± 7.7%. The femoral socket locations were considered as anatomic in accordance with previous cadaveric studies examining the positions of ACL femoral insertion site. Subjectively, the mean Lysholm score was 96.9 ± 4.0 points. According to IKDC final objective scores, 26 knees (76%) were objectively graded as normal, 8 (24%) as nearly normal, and 0 (0%) as abnormal or severely abnormal. Postoperative side-to-side anterior translation measured with a KT-2000 arthrometer averaged 0.7 ± 1.2 mm.

CONCLUSIONS

DB ACL reconstructions in which femoral socket apertures were validated anatomically using 3D CT provided satisfactory short-term results.

LEVEL OF EVIDENCE

Case series, Level IV.

Commonly used ACL autograft areas do not correlate with the size of the ACL footprint or the femoral condyle

PURPOSE

The purpose of this study was to reveal the correlation between the size of the native anterior cruciate ligament (ACL) footprint and the area of commonly used autografts using cadaveric knees.

METHODS

Twenty-Four non-paired human cadaver knees were used. The size of the femoral and tibial ACL footprints, length of Blumensaat's line, and the height and area of the lateral wall of the femoral intercondylar notch were photographed and measured with Image J software (National Institution of Health). Simulating an semitendinosus tendon (ST) graft, the ST was cut in half. The bigger half was regarded as the antero-medial (AM) bundle, and the remaining half was regarded as the postero-lateral (PL) bundle. Simulating an semitendinosus and gracilis (ST-G) graft, the bigger half of the ST and G was regarded as the AM bundle, and the smaller half of the ST was regarded as the PL bundle. Each graft diameter was measured, and the graft area was calculated. Simulating a bone-patella tendon-bone (BPTB) graft, a 10-mm wide BPTB graft was harvested and the area calculated.

RESULTS

The sizes of the native femoral and tibial ACL footprints were 72.3 ± 24.4 and 134.1 ± 32.4 mm(2), respectively. The length of Blumensaat's line, and the height and area of the lateral wall of the femoral intercondylar notch were 29.5 ± 2.5 mm, 17.7 ± 2.3 mm, and 400.9 ± 62.6 mm(2), respectively. The average areas of the ST, ST-G, and BPTB graft were 52.7 ± 6.3, 64.7 ± 7.6, and 37.1 ± 7.5 mm(2). Both the height and the area of the lateral wall of the femoral intercondylar notch were significantly correlated with the femoral size of the ACL footprint (p = 0.007 and 0.008, respectively). However, no significant correlation was observed between ACL footprint size and autograft size. No significant correlation was observed between autograft size and the size of the lateral wall of the femoral intercondylar notch.

CONCLUSION

In ACL reconstruction, if the reconstructed ACL size is determined by the harvested autograft size alone, native ACL size and anatomy are unlikely to be reproduced.

Graft size after anterior cruciate ligament reconstruction

PURPOSE

The native anterior cruciate ligament (ACL) is composed of two distinct bundles, the anteromedial (AM) and posterolateral (PL), and both have been shown to be reliably measured on magnetic resonance imaging (MRI). The purpose of this study was to measure the size of the AM and PL bundles after ACL double-bundle reconstructions on MRI and compare this to the relative graft size at the time of surgery.

METHODS

Between January 2007 and April 2010, 85 knees were identified after allograft double-bundle ACL reconstruction with post-operative MRI (1.5 T) and met inclusion criteria. On standard sagittal, coronal and oblique coronal MRIs, the AM and PL bundles were delineated and the midsubstance width of the ACL graft was measured. The images were independently measured in a blinded fashion by two observers. Linear and curvilinear regression analysis was used to analyse the relationship between graft size and time after reconstruction.

RESULTS

The mean age of the patients was 24.6 years (SD 10.4). Mean time from surgery to post-operative MRI was 271.5 days (SD 183.4). The mean percentage of the original size of the AM bundle was 86.9% (SD 9.9) and of the PL bundle was 88.6% (SD 9.9). There was no correlation between the relative size of the AM graft and the time from surgery (r = 0.3, n.s.) and no significant relationship for the PL graft (r = 0.1, n.s).

CONCLUSION

On average, there was no graft enlargement of the AM and PL grafts 275.1 days after allograft ACL double-bundle reconstruction, as the mean relative graft size was less than 100 % on MRI. This study suggests that surgeons, who use allografts, should measure the ACL and replace it with a similar size, as there is a low risk of hypertrophy of the graft within one year post-operative.

LEVEL OF EVIDENCE

IV.

Anatomic single- versus double-bundle ACL reconstruction: a meta-analysis

PURPOSE

To determine whether anatomic double-bundle anterior cruciate ligament (ACL) reconstruction compared to anatomic single-bundle ACL reconstruction more effectively restored antero-posterior (A-P) laxity, rotatory laxity and reduced frequency of graft rupture. Our hypothesis was that anatomic double-bundle ACL reconstruction results in superior rotational knee laxity and fewer graft ruptures due to its double-bundle tension pattern, compared with anatomic single-bundle ACL reconstruction.

METHODS

An electronic search was performed using the PubMed, EMBASE and Cochrane Library databases. All therapeutic trials written in English reporting knee kinematic outcomes and graft rupture rates of primary anatomic double- versus single-bundle ACL reconstruction were included. Only clinical studies of levels I-II evidence were included. Data regarding kinematic tests were extracted and included pivot-shift test, Lachman test, anterior drawer test, KT-1000 measurements, A-P laxity measures using navigation and total internal-external (IRER) laxity measured using navigation, as well as graft failure frequency.

RESULTS

A total of 7,154 studies were identified of which 15 papers (8 randomized controlled trials and 7 prospective cohort studies, n = 970 patients) met the eligibility criteria. Anatomic ACL double-bundle reconstruction demonstrated less anterior laxity using KT-1000 arthrometer with a standard mean difference (SMD) = 0.36 (95% CI 0.214-0.513, p < 0.001) and less A-P laxity measured with navigation (SMD = 0.29 95% CI 0.01-0.565, p = 0.042). Anatomic double-bundle ACL reconstruction did not lead to significant improvements in pivot-shift test, Lachman test, anterior drawer test, total IRER or graft failure rates compared to anatomic single-bundle ACL reconstruction.

CONCLUSION

Anatomic double-bundle ACL reconstruction is superior to anatomic single-bundle reconstruction in terms of restoration of knee kinematics, primarily A-P laxity. Whether these improvements of laxity result in long-term improvement of clinical meaningful outcomes remains uncertain.

LEVEL OF EVIDENCE

II.

Comparison of transtibial and transportal techniques in drilling femoral tunnels during anterior cruciate ligament reconstruction using 3D-CAD models

Purpose

The purpose of this study was to assess the differences in bone tunnel apertures between the trans-accessory medial portal (trans-AMP) technique and the transtibial (TT) technique in double-bundle anterior cruciate ligament reconstruction. The extent of ovalization and the frequency of overlap of the two tunnel apertures were compared.

Methods

The simulation of femoral tunnel drilling with the TT and the trans-AMP techniques was performed using three-dimensional computer aided design models from two volunteers. The incidence angle of drilling against the intercondylar wall, the femoral tunnel position, the ovalization, and the overlap were analyzed. The aperture and location of the tunnels were also examined in real anterior cruciate ligament reconstruction cases (n=36).

Results

The surgical simulation showed that a lower drill incident angle induced by the TT technique made the apertures of two tunnels more ovalized, located anteromedial tunnels in a shallower position to prevent posterior wall blow out, and led to a higher frequency of tunnel overlap. The trans-AMP group had tunnel places within the footprint and had less ovalization and overlap. The results of analysis for tunnels in the clinical cases were consistent with results from the surgical simulation.

Conclusion

In the TT technique, the shallow anteromedial tunnel location and more ovalized tunnel aperture can lead to a higher frequency of tunnel overlap. Compared with the TT technique, the trans-AMP technique was more useful in preparing femoral tunnels anatomically and avoiding tunnel ovalization and overlapping in double-bundle anterior cruciate ligament reconstruction.

A Preliminary In Vivo Assessment of Anterior Cruciate Ligament-Deficient Knee Kinematics With the KneeM Device: A New Method to Assess Rotatory Laxity Using Open MRI

BACKGROUND

Methods of objectively measuring rotational knee laxity are either experimental or difficult to use in daily practice. A new method has been developed to quantitatively assess rotatory laxity using an open MRI system and new tool, the KneeM device.

PURPOSE/HYPOTHESIS

To perform a preliminary evaluation of a novel knee rotation measurement device to assess knee kinematics during flexion in an MRI field, in both anterior cruciate ligament (ACL)-deficient and healthy contralateral knees. The hypothesis was that the KneeM device would allow in vivo reproduction and analysis of knee kinematics during flexion in healthy and ACL-deficient knees.

STUDY DESIGN

Controlled laboratory study.

METHODS

Ten subjects (7 men and 3 women; mean age ± standard deviation, 32.3 ± 9.4 years) with ACL-deficient knees and contralateral uninjured knees participated in the study. An open MRI was performed with the KneeM device at a mean 4.9 months (range, 3.0-7 months) after ACL injury. The device exerted on the knee an anterior drawer force of 100 N, with an internal rotation of 20°, through the range of flexion (0°, 20°, 40°, and 60°). Both ACL-deficient and healthy contralateral knees were analyzed using the Iwaki method.

RESULTS

There was no statistical difference of anterior translation in the medial compartment between intact and ACL-deficient knees at all degrees of flexion. However, significant differences in the anterior translation of the lateral compartment were observed between ACL-deficient and intact contralateral knees at 0° and 20° of flexion (P = .005 and P = .002, respectively). Between 20° and 40°, the lateral plateau of ACL-deficient knees translated 7.7 mm posteriorly, whereas the medial compartment remained stable, reflecting a sudden external rotation of the lateral plateau under the femoral condyle.

CONCLUSION

This preliminary study suggests that measurement of tibiofemoral movements in both compartments during flexion using the KneeM device was useful for quantifying rotatory laxity in ACL-deficient knees. Moreover, this device seemed to allow a "mechanized pivot shift" and allowed reproduction of the "pivot" phase in the MRI field between 20° and 40° of flexion.

CLINICAL RELEVANCE

This device could be used for diagnostic purposes or to investigate the outcomes of ACL reconstructions.

In vivo three-dimensional imaging analysis of femoral and tibial tunnel locations in single and double bundle anterior cruciate ligament reconstructions

BACKGROUND

Anatomic footprint restoration of anterior cruciate ligament (ACL) is recommended during reconstruction surgery. The purpose of this study was to compare and analyze the femoral and tibial tunnel positions of transtibial single bundle (SB) and transportal double bundle (DB) ACL reconstruction using three-dimensional computed tomography (3D-CT).

METHODS

In this study, 26 patients who underwent transtibial SB ACL reconstruction and 27 patients with transportal DB ACL reconstruction using hamstring autograft. 3D-CTs were taken within 1 week after the operation. The obtained digital images were then imported into the commercial package Geomagic Studio v10.0. The femoral tunnel positions were evaluated using the quadrant method. The mean, standard deviation, standard error, minimum, maximum, and 95% confidence interval values were determined for each measurement.

RESULTS

The femoral tunnel for the SB technique was located 35.07% ± 5.33% in depth and 16.62% ± 4.99% in height. The anteromedial (AM) and posterolateral (PL) tunnel of DB technique was located 30.48% ± 5.02% in depth, 17.12% ± 5.84% in height and 34.76% ± 5.87% in depth, 45.55% ± 6.88% in height, respectively. The tibial tunnel with the SB technique was located 45.43% ± 4.81% from the anterior margin and 47.62% ± 2.51% from the medial tibial articular margin. The AM and PL tunnel of the DB technique was located 33.76% ± 7.83% from the anterior margin, 45.56% ± 2.71% from the medial tibial articular margin and 53.19% ± 3.74% from the anterior margin, 46.00% ± 2.48% from the medial tibial articular margin, respectively. The tibial tunnel position with the transtibial SB technique was located between the AM and PL tunnel positions formed with the transportal DB technique.

CONCLUSIONS

Using the 3D-CT measuring method, the location of the tibia tunnel was between the AM and PL footprints, but the center of the femoral tunnel was at more shallow position from the AM bundle footprint when ACL reconstruction was performed by the transtibial SB technique.

Basic science of anterior cruciate ligament injury and repair

Injury to the anterior cruciate ligament (ACL) is one of the most devastating and frequent injuries of the knee. Surgical reconstruction is the current standard of care for treatment of ACL injuries in active patients. The widespread adoption of ACL reconstruction over primary repair was based on early perception of the limited healing capacity of the ACL. Although the majority of ACL reconstruction surgeries successfully restore gross joint stability, post-traumatic osteoarthritis is commonplace following these injuries, even with ACL reconstruction. The development of new techniques to limit the long-term clinical sequelae associated with ACL reconstruction has been the main focus of research over the past decades. The improved knowledge of healing, along with recent advances in tissue engineering and regenerative medicine, has resulted in the discovery of novel biologically augmented ACL-repair techniques that have satisfactory outcomes in preclinical studies. This instructional review provides a summary of the latest advances made in ACL repair. Cite this article: Bone Joint Res 2014;3:20-31.

Prospective randomized comparison of anatomic single- and double-bundle anterior cruciate ligament reconstruction

PURPOSE

To determine if anatomic double-bundle anterior cruciate ligament (ACL) reconstruction is superior to anatomic single-bundle reconstruction in restoring the stabilities and functions of the knee joint.

METHODS

A prospective randomized clinical study was done to compare the results of 32 cases of anatomic single-bundle ACL reconstruction and 34 cases of anatomic double-bundle ACL reconstruction with average follow-up of 16.3 ± 3.1 months. Tunnel placements of all the cases were measured on 3D CT. Clinical results were collected after reconstruction; graft's appearance, meniscus status and cartilage state under arthroscopy were compared and analysed too.

RESULTS

Tunnel placements, confirmed with 3D CT, were in the anatomic positions as described in literature both in SB and DB group. No differences were found between SB and DB groups in clinical outcome scores, pivot shift test and KT 1000 measurements (average side-to-side difference for anterior tibial translation was 0.7 mm in SB group and 1.0 mm in DB group). More than 70 % of the single-bundle graft and AM bundle graft in DB group appeared excellent, but only 44.1 % of PL bundle grafts in DB group were excellent and 11.8 % were in poor state. No new menisci tear was found either in SB or DB group, however, in DB group cartilage damages in medial patella-femoral joint occurred in 38.2 % cases. This rate was significantly higher than in the SB group which is only 9.3 %.

CONCLUSION

Both single- and double-bundle anatomic ACL reconstruction can restore the knee's stability and functions very well. However, more incidences of poor PL status and medial patellar-femoral cartilage damage may occur in double-bundle ACL reconstruction.

Single-bundle or double-bundle for anterior cruciate ligament reconstruction: a meta-analysis

PURPOSE

To compare the clinical outcomes of anterior cruciate ligament (ACL) reconstruction with double-bundle and single-bundle techniques.

STUDY DESIGN

Meta-analysis

METHODS

We searched electronic databases including PubMed, Embase, Cochrane Central Register of Controlled Trials, and Google Scholar from 1966 to Jan 2012 to identify randomized controlled trials (RCTs) comparing clinical outcomes of anterior cruciate ligament (ACL) reconstruction with double-bundle and single-bundle techniques. Two reviewers independently extracted data and assessed trial quality. Meta-analysis was performed to pool results.

RESULTS

Nineteen RCTs were included with a total of 1686 patients. The pooled analysis across all studies showed that the double-bundle ACL reconstruction technique could have significantly better outcomes in rotational laxity, as assessed by the pivot-shift test, KT grading and IKDC grading than the single-bundle techniques. We found no evidence of a difference in function measured by IKDC scores, KT arthrometer, Lysholm knee, or Tegner activity scores and complications after operations between single and double-bundle ACL reconstruction groups.

CONCLUSION

Our meta-analysis demonstrated the superiority of double-bundle over single-bundle anterior cruciate ligament reconstruction. The double-bundle ACL reconstruction technique has better outcomes in rotational laxity (pivot-shift test, KT grading and IKDC grading). However, for functional recovery, there was no significant difference between single-bundle and double-bundle reconstruction techniques.

Evaluation of ACL mid-substance cross-sectional area for reconstructed autograft selection

PURPOSE

The purpose of this study was to compare the size of the native ACL mid-substance cross-sectional area and the size of commonly used autografts. Hypothesis of this study was that the reconstructed graft size with autografts would be smaller than the native ACL size.

METHODS

Twelve non-paired human cadaver knees were used. The ACL was carefully dissected, and the mid-substance of the ACL was cross-sectioned parallel to the articular surface of the femoral posterior condyles at 90 degrees of knee flexion. The size of the cross-sectional area of the ACL, and the femoral and tibial footprints were measured using Image J software (National Institute of Health). The semitendinosus tendon (ST) and the gracilis (G) tendon were harvested and prepared for ACL grafts. Simulating an ST graft, the ST was cut in half. The bigger half was regarded as the antero-medial (AM) bundle, and the remaining half was regarded as the postero-lateral (PL) bundle. Simulating an ST-G graft, the bigger half of the ST and G were regarded as the AM bundle, and the smaller half of the ST was regarded as the PL bundle. Each graft diameter was measured, and the graft area was calculated. Simulating a rectangular bone-patella tendon-bone (BPTB) graft, a 10-mm-wide BPTB graft was harvested and the area calculated.

RESULTS

The sizes of the ACL mid-substance cross-sectional area, femoral and tibial ACL footprint were 46.9 ± 18.3, 60.1 ± 16.9 and 123.5 ± 12.5 mm(2), respectively. The average areas of the ST, ST-G, and BPTB grafts were 52.0 ± 3.8, 64.4 ± 6.2, and 40.8 ± 6.7 mm(2), respectively. The ST and BPTB grafts showed no significant difference in graft size when compared with the ACL cross-sectional area.

CONCLUSION

ST and BPTB autografts were able to reproduce the native size of the ACL mid-substance cross-sectional area. The ST-G graft was significantly larger than the ACL cross-sectional area. For clinical relevance, ST and BPTB grafts are recommended in order to reproduce the native size of the ACL in anatomical ACL reconstruction with autograft.

Single-bundle anterior cruciate ligament reconstruction: a biomechanical cadaveric study of a rectangular quadriceps and bone--patellar tendon--bone graft configuration versus a round hamstring graft

PURPOSE

The purposes of this study were to investigate anterior tibial translation under loading conditions after single-bundle (SB) anterior cruciate ligament (ACL) reconstruction using a rectangular tunnel placement strategy with quadriceps and bone--patellar tendon--bone (BPTB) graft and to compare these data with a SB hamstring reconstruction with a round tunnel design.

METHODS

In 9 human cadaveric knees, the knee kinematics were examined with robotic/universal force-moment sensor testing. Within the same specimen, the knee kinematics under simulated pivot-shift and KT-1000 arthrometer (MEDmetric, San Diego, CA) testing were determined at 0°, 15°, 30°, 60°, and 90° of flexion under different conditions: intact knee, ACL-deficient knee, and SB ACL-reconstructed knee. For the SB ACL-reconstructed knee, 3 different SB reconstruction techniques were used: a rectangular tunnel strategy (9 × 5 mm) with quadriceps graft, a rectangular tunnel strategy with BPTB graft, and a round tunnel strategy (7 mm) with hamstring graft.

RESULTS

In a simulated Lachman test, a statistically significant difference was found at 0° and 15° of knee flexion between the rectangular reconstruction with quadriceps graft (5.1 ± 1.2 mm and 8.3 ± 2 mm, respectively) or BPTB graft (5.3 ± 1.5 mm and 8 ± 1.9 mm, respectively) and the reconstruction using hamstring graft (7.2 ± 1.4 mm and 12 ± 1.8 mm, respectively) (P = .032 and P = .033, respectively, at 0°; P = .023 and P = .02, respectively, at 15°). On the simulated pivot-shift test at 0° and 15°, rectangular ACL reconstruction with quadriceps graft (3.9 ± 2.1 mm and 6.5 ± 1.7 mm, respectively) or BPTB graft (4.2 ± 1.8 mm and 6.7 ± 1.7 mm, respectively) showed a significantly lower anterior tibial translation when compared with round tunnel reconstruction (5.5 ± 2.1 mm and 7.9 ± 1.9 mm, respectively) (P = .03 and P = .041, respectively, at 0°; P = .042 and P = .046, respectively, at 15°).

CONCLUSIONS

Under simulated Lachman testing and pivot-shift testing, a reconstruction technique using a rectangular tunnel results in significantly lower anterior tibial translation at 0° and 15° of flexion in comparison to knees reconstructed with a hamstring SB graft using a round tunnel strategy.

CLINICAL RELEVANCE

ACL reconstruction with a rectangular tunnel and BPTB and quadriceps tendon might result in better anterior knee stability at low flexion angles than ACL reconstruction with hamstring SB graft and a round tunnel in the clinical setting.

The shape and the thickness of the anterior cruciate ligament along its length in relation to the posterior cruciate ligament: a cadaveric study

PURPOSE

The purpose of this study was to evaluate the shape of the native anterior cruciate ligament (ACL) along its length in relation to the posterior cruciate ligament (PCL) and compare it with the size of the 3 commonly used autografts (bone-patellar tendon-bone [BPTB], single-bundle hamstring, and double-bundle hamstring).

METHODS

With the knee in extension, we filled the intercondylar notch with paraffin, fixing the cruciate ligaments in their natural position, in 8 cadaveric specimens. The ACL-PCL tissue specimen, embedded in paraffin, was removed en bloc. Gross sections were prepared in the coronal plane and were evaluated histologically. The width, thickness, and cross-sectional area of both the ACL and PCL were determined. The dimensions of the semitendinosus tendon (ST), gracilis tendon (GT), and BPTB grafts were measured and compared with those of the native ACL.

RESULTS

The PCL occupies the largest part of the intercondylar area, leaving only a small space for the ACL in knee extension. The ACL midsubstance has a width of 5 mm, resembling a band shape. Only before its tibial insertion does the ACL fan out and take the form of its tibial attachment. The BPTB graft has a thickness of 5.8 mm, whereas the ST and GT grafts have a thickness of 6.25 mm and 4.5 mm, respectively, and are comparable to the midsubstance of the ACL but undersized in the tibial insertion (P = .0016 for BPTB graft, P = .002 for ST graft, and P = .0003 for GT graft). A quadruple-looped ST-GT graft, with a diameter of 8 mm, is oversized in the midsubstance (P = .0002) but fits better in the tibial attachment.

CONCLUSIONS

The ACL midsubstance has a width of 5 mm, resembling a band shape. Before its tibial insertion, the ACL fans out like a trumpet, taking the form of its wide tibial attachment.

CLINICAL RELEVANCE

The dimensions of the native ACL have to be considered in graft selection for anatomic ACL reconstruction.

TriLink: Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction

Cadaveric and clinical biomechanical studies show improved kinematic restoration using double-bundle anterior cruciate ligament (ACL) reconstruction techniques. These have been criticized in the past for being technically challenging. We present a novel 3-socket approach for anatomic "all-inside" double-bundle reconstruction using a single hamstring tendon fashioned to create a trifurcate graft: the TriLink technique. The semitendinosus alone is harvested, quadrupled, and attached to 3 suspensory fixation devices in a Y-shaped configuration, creating a 4-stranded tibial limb and 2 double-stranded femoral limbs. A medial viewing/lateral working arthroscopic approach is adopted using specifically designed instrumentation. Anatomic placement of the 2 femoral tunnels is performed by a validated direct measurement technique. A single mid-bundle position is used on the tibia. Both femoral and tibial sockets are created in a retrograde manner using outside-to-in drilling. This is a simplified operative technique for anatomic double-bundle ACL reconstruction that maximizes bone preservation. The TriLink construct replicates the 2 bundles of the ACL, conferring native functional anisometry and improving femoral footprint coverage while avoiding the complexities and pitfalls of double-tibial tunnel techniques. Preservation of the gracilis reduces the morbidity of hamstring harvest and allows greater flexibility in graft choice in cases requiring multiligament reconstruction.

Progression of osteoarthritis after double- and single-bundle anterior cruciate ligament reconstruction

BACKGROUND

No consensus has been reached on the advantages of double-bundle (DB) anterior cruciate ligament reconstruction (ACLR) over the single-bundle (SB) technique, particularly with respect to the prevention of osteoarthritis (OA) after ACLR.

PURPOSE

To evaluate whether DB ACLR has any advantages in the prevention of OA or provides better stability and function after ACLR compared with the SB technique.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

A total of 130 patients with an ACL injury in one knee were prospectively randomized into a DB group (n = 65) or an SB group (n = 65). For the radiologic evaluation, we determined the degree of OA based on the Kellgren-Lawrence grade before the operation and at the time of the final follow-up and determined the number of patients with progression of OA more than one grade from pre- to postoperation. We evaluated the stability results using the Lachman and pivot-shift tests and stress radiography. We also compared the functional outcomes based on the Lysholm knee score, Tegner activity score, and International Knee Documentation Committee (IKDC) subjective scale.

RESULTS

Six patients (4 in the DB group and 2 in the SB group) suffered graft failure during the follow-up and had ACL revision surgery (P = .06). A total of 112 patients were observed for a minimum of 4 years (DB group, n = 52; SB group, n = 60). Five patients (9.6%) in the DB group and 6 patients (10%) in the SB group had more advanced OA at the final follow-up (P = .75). All patients recovered full range of motion within 6 months from surgery. Stability results of the Lachman test, pivot-shift test, and the radiographic stability test failed to reveal any significant intergroup differences (P = .37, .27, and .67, respectively). In the pivot-shift result, the DB group had 4 patients with grade 2 and the SB group had 3 patients with grade 2 (P = .27). Clinical outcomes, including Lysholm knee and Tegner activity scores, were similar in the 2 groups. Statistical significance was achieved only for the IKDC subjective scale (78.2 in DB group vs 73.1 in SB group; P = .03).

CONCLUSION

The DB technique, compared with SB, was not more effective in preventing OA and did not have a more favorable failure rate. Although the DB ACLR technique produced a better IKDC subjective scale result than did the SB ACLR technique, the 2 modalities were similar in terms of clinical outcomes and stability after a minimum 4 years of follow-up.

Prospective clinical comparisons of semitendinosus versus semitendinosus and gracilis tendon autografts for anatomic double-bundle anterior cruciate ligament reconstruction

BACKGROUND

The data available from the previously reported clinical studies remains insufficient concerning the hamstring graft preparation in double-bundle anterior cruciate ligament (ACL) reconstruction.

OBJECTIVE

To test the hypothesis that there are no significant differences between the semitendinosus tendon alone and the semitendinosus and gracilis tendon graft fashioning techniques concerning knee stability and clinical outcome after anatomic double-bundle ACL reconstruction.

METHODS

A prospective study was performed on 120 patients who underwent anatomic double-bundle ACL reconstruction according to the graft fashioning technique. The authors developed the protocol to use hamstring tendon autografts. When the harvested doubled semitendinosus tendon is thicker than 6 mm, each half of the semitendinosus tendon is doubled and used for the anteromedial (AM) and posterolateral (PL) bundle grafts (Group I). On the other hand, when the harvested semitendinosus tendon is under 6 mm in thickness, the gracilis tendon is harvested additionally. The distal half of the semitendinosus and gracilis tendons are doubled and used for the AM bundle graft, and the remaining proximal half of the semitendinosus tendon is doubled and used for the PL bundle grafts (Group II). Sixty-one patients were included in Group I, and 59 patients in Group II. The two groups were compared concerning knee stability and clinical outcome 2 years after surgery.

RESULTS

The postoperative side-to-side anterior laxity averaged 1.3 mm in both groups, showing no statistical difference. There were also no significant differences between the two groups concerning the peak isokinetic torque of the quadriceps and the hamstrings, the Lysholm knee score, and the International Knee Documentation Committee evaluation.

CONCLUSION

There were no significant differences between the two graft fashioning techniques after anatomic double-bundle ACL reconstruction concerning knee stability and postoperative outcome. The present study provided orthopedic surgeons with important information on double-bundle ACL reconstruction with hamstring tendons.

LEVEL OF EVIDENCE

Level II; prospective comparative study.

Functional outcomes of Y-graft double-bundle and single-bundle anterior cruciate ligament reconstruction of the knee

PURPOSE

The purpose of this study was to compare the functional outcome, ligament laxity, and tibial tunnel enlargement between 3-tunnel double-bundle (DB) anterior cruciate ligament (ACL) and single-bundle (SB) ACL reconstruction.

METHODS

This retrospective study identified primary arthroscopic ACL reconstruction from July 2006 to July 2008. The cohort consisted of 50 knees in 49 patients, comprising 26 knees with SB ACL reconstruction and 24 with DB ACL reconstruction. Semitendinosus autograft was used in SB ACL reconstruction, and semitendinosus and gracilis grafts were used in DB ACL reconstruction. Both groups received the same rehabilitation protocol postoperatively. The evaluations included functional assessment, ligament laxity, and radiographs of the knee. Functional assessments included a pain score, the Lysholm functional score, the Tegner activity score, and the grade on the International Knee Documentation Committee knee examination form. Ligament laxity was measured by the anterior drawer test, Lachman test, pivot-shift test, and KT-1000 arthrometer (MEDmetric, San Diego, CA) testing. It was graded as 0 for no laxity, 0 to 5 mm for mild laxity, 5 to 10 mm for moderate laxity, and 10 to 15 mm for severe laxity. Radiographs of the knee were used for the evaluation of bony appearance, alignment of the knee, joint space narrowing, and measurement of the tibial tunnel.

RESULTS

Significant improvements in knee function and ligament laxity were noted after surgery in both groups. However, no statistical differences in functional scores and ligament laxity were noted between the 2 groups (P = .275 and P = .413, respectively). A mild increase in laxity was noted in 3 cases (14%) in the DB ACL reconstruction group and 3 cases (13%) in the SB ACL reconstruction group. A moderate increase in laxity was noted in 2 cases (9%) in the SB ACL reconstruction group and none in the DB ACL reconstruction group. Radiographic evaluations showed no statistical difference between the 2 groups (P = .114).

CONCLUSIONS

Both 3-tunnel Y-graft DB ACL reconstruction and SB ACL reconstruction significantly improved the function and stability of the knee after surgery.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Surgical and Biomechanical Perspectives on Osteoarthritis and the ACL Deficient Knee: A Critical Review of the Literature

This review was undertaken to better understand the debate regarding the issue of osteoarthritis associated with anterior cruciate ligament (ACL) injuries, from a surgical and biomechanical standpoint. Much of the current debate focuses on contributory surgical factors and their relative roles in increasing or decreasing the risk of future osteoarthritis development, primarily highlighting the controversy over whether reconstructive surgery itself is necessarily protective. This review addresses the evolution of ACL reconstruction techniques over time, and with a view to thoroughly examine the role of surgery, outcome differences in procedural technique are reviewed, with a focus on open versus arthroscopic methods, graft choice and the use of a double versus single bundle reconstruction technique. Moreover, other potentially important contributory factors are identified and discussed, such as intrinsic biomechanical alterations sustained at the time of initial injury, and how these may have a more significant role with regard to future osteoarthritic changes in the knee than previously attributed.

A quantitative technique to create a femoral tunnel at the averaged center of the anteromedial bundle attachment in anatomic double-bundle anterior cruciate ligament reconstruction

Background

In the anatomic double-bundle ACL reconstruction, 2 femoral tunnel positions are particularly critical to obtain better clinical results. Recently, a few studies have reported quantitative identification methods for posterolateral (PL) bundle reconstruction. Concerning anteromedial (AM) bundle reconstruction, however, no quantitative clinically available methods to insert a guide wire at the center of the direct attachment of the AM mid-substance fibers have been reported to date.

Methods

First, we determined the center of the femoral attachment of the AM mid-substance fibers using 38 fresh frozen cadaveric knees. Based on this anatomical sub-study, we developed a quantitative clinical technique to insert a guide wire at the averaged center for anatomic double-bundle ACL reconstruction. In the second clinical sub-study with 63 patients who underwent anatomic ACL reconstruction with this quantitative technique, we determined the center of an actually created AM tunnel. Then, we compared the results of the second sub-study with those of the first sub-study to validate the accuracy of the quantitative technique. In both the sub-studies, we determined the center of the anatomical attachment and the tunnel outlet using the “3-dimensional clock” system. The tunnel outlet was evaluated using the “transparent” 3-dimensional computed tomography.

Results

The averaged center of the direct attachment of the AM bundle midsubstance fibers was located on the cylindrical surface of the femoral intercondylar notch at “10:37” (or “1:23”) o’clock orientation in the distal view and at 5.0-mm from the proximal outlet of the intercondylar notch (POIN) in the lateral view. The AM tunnel actually created in ACL reconstruction was located at “10:41” (or “1:19”) o’clock orientation in the average and at 5.0-mm from the POIN. There was no significant difference between the 2 center locations.

Conclusions

The quantitative technique enabled us to easily create the femoral AM tunnel at the averaged center of the direct attachment of the AM bundle midsubstance fibers with high accuracy. This study reported information on the geometric location of the femoral attachment of the AM bundle and a clinically useful technique for its anatomical reconstruction.

Double-bundle anterior cruciate ligament reconstruction with split Achilles allograft and single tibia tunnel for small ACL tibial footprint : technical note with clinical results

PURPOSE

We describe a surgical technique of double-bundle ACL reconstruction with a single tibia tunnel and report the clinical outcome.

METHODS

The Achilles tendon portion was split longitudinally into two separate bundles, namely, an anteromedial (AM) bundle with 7-8 mm diameter and a posterolateral (PL) bundle with 4-6 mm diameter. The central portion of the calcaneal bone plug was prepared with a diameter of 10 mm and a length of 30 mm. For the femoral tunnel preparation, we preferred inside out target through an accessory anteromedial portal for an approach to native ACL footprint and outside in reaming through separate incision on the lateral aspect of distal thigh to prevent cartilage injury of medial femoral condyle. 10 mm diameter of single tibia tunnel was prepared at the central portion of ACL tibial footprint. After graft passage from tibia to femoral side, fixation of calcaneal bone plug within the tibia tunnel was performed using two bioabsorbable cross pins. Then, AM bundle was first fixed at 45° of flexion while the PL bundle was fixed at 10° of flexion using bioabsorbable interference screws and augmented staples. Clinical results of 22 patients (18 males and 4 females, average age 30.7 years) who underwent double-bundle anterior cruciate ligament (ACL) reconstruction with this technique were evaluated.

RESULTS

At an average follow-up of 30 months, there was significant improvement of the Lysholm knee score, the 2,000 IKDC subjective knee score, the median Tegner activity score and the side-to-side difference. According to the 2,000 IKDC knee examination form, the grade rated as normal in seven patients, nearly normal in 14 patients and abnormal in one patient at the latest follow-up. There were no postoperative complications and revisional surgeries.

CONCLUSIONS

Split Achilles allograft and single tibia tunnel technique for double-bundle ACL reconstruction can be an alternative option for patients with small tibial insertion sites.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Tunnel Enlargement and Coalition After Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction With Hamstring Tendon Autografts: A Computed Tomography Study

Background:

Tunnel enlargement and coalition following double-bundle anterior cruciate ligament (ACL) reconstruction with hamstring tendon autografts has not yet been sufficiently studied.

Hypothesis:

The incidence and the degree of femoral tunnel enlargement will be significantly greater than those for tibial tunnel enlargement after anatomic double-bundle ACL reconstruction using hamstring tendon autografts. There will be no significant correlation between tunnel enlargement and coalition and the postoperative knee laxity.

Study Design:

Case series; Level of evidence, 4.

Methods:

Thirty-nine patients who underwent anatomic double-bundle ACL reconstruction using semitendinosus and gracilis tendon autografts were followed up for 1 year after surgery. The grafts were simultaneously fixed at 10° of knee flexion with EndoButtons and spiked staples. All patients were examined with computed tomography and the standard clinical evaluation methods at 2 weeks and 1 year after surgery.

Results:

The degree of tunnel enlargement of the femoral anteromedial and posterolateral tunnels averaged 10% to 11% and 7% to 9%, respectively, while that of the tibial anteromedial and posterolateral tunnels averaged 3% to 7% and 1% to 6%. The degree and incidence of the anteromedial and posterolateral tunnel enlargement were significantly greater in the femur than in the tibia (P < .0335 and P < .0405, respectively). On the femoral and tibial intra-articular surface, tunnel outlet coalition was found in 5% and 77% of the knees, respectively, at 1 year after surgery. There was no significant correlation between tunnel enlargement and coalition and the clinical outcome.

Conclusion:

The incidence and the degree of each tunnel enlargement in the femur were significantly greater than that in the tibia. However, the incidence of tunnel coalition in the femur was significantly less than that in the tibia after double-bundle ACL reconstruction with a transtibial technique. There was no significant correlation between tunnel enlargement and coalition and the clinical outcome.

Clinical Relevance:

The present study provides orthopaedic surgeons with important information on double-bundle ACL reconstruction with hamstring tendons.

Optimal graft length for anterior cruciate ligament reconstruction: a biomechanical study in beagles

The anterior cruciate ligament (ACL) is a major ligament that helps maintain the stability of the knee joint. Injury to the ACL can be treated by replacing the torn ligament. This study determined the optimal flexor tendon length in the bone tunnel in ACL reconstruction.Autologous ACL reconstruction was performed using a flexor tendon in 54 male beagles, with the graft length in the bone tunnel at 5, 9, 13, 17, 21, and 25 mm (9 dogs per graft length). The maximum tensile strength and stiffness of the reconstructed joint (tibia-ACL-femur triad) were recorded at 45, 90, and 180 days after ACL reconstruction (6 joints per time point). The experiment also included an intact control group (3 dogs) and a control group tested immediately after the reconstruction (3 dogs). For the intact control group, the normal ACL (unreconstructed) and flexor tendon mechanical testing was performed. For the other control group, the normal ACL (unreconstructed) mechanical testing was performed first and then mechanical testing of the specimens was performed immediately after reconstruction. The maximum tensile strength and stiffness of the reconstructed tibia-ACL-femur triad increased with time after reconstruction, regardless of the graft length in the bone tunnel. Maximum tensile strength and stiffness of the grafts increased with graft length but reached a plateau at 17 mm. Optimal strength and stiffness of the reconstructed ACL are achieved with 17-mm grafts.

Size comparison of ACL footprint and reconstructed auto graft

PURPOSE

The purpose of this study was to compare the size of native anterior cruciate ligament (ACL) footprints and the size of commonly used auto grafts. The hypothesis was that the reconstructed graft size with auto grafts might be smaller than the native ACL footprint.

METHODS

Fourteen non-paired human cadaver knees were used. The semitendinosus tendon (ST) and the gracilis (G) tendon were harvested and prepared for ACL grafts. Simulating an ST graft, the ST was cut in half. The bigger half was regarded as the antero-medial (AM) bundle, and the remaining half was regarded as the postero-lateral (PL) bundle. Simulating an ST-G graft, the bigger half of the ST and G were regarded as the AM bundle, and the smaller half of the ST was regarded as the PL bundle. Each graft diameter was measured, and the graft area was calculated. Simulating a rectangular bone-patella tendon-bone (BPTB) graft, a 10-mm wide BPTB graft was harvested and the area calculated. The ACL was carefully dissected, and the size of the femoral and tibial footprints was measured using Image J software (National Institution of Health).

RESULTS

The average areas of the ST, ST-G, and BPTB graft were 52.3 ± 7.3, 64.4 ± 9.2, and 32.7 ± 6.5 mm(2), respectively. The sizes of the native femoral and tibial ACL footprints were 85.4 ± 26.3 and 145.4 ± 39.8 mm(2), respectively. Only the ST-G graft showed no significant difference in graft size when compared with the femoral ACL footprint.

CONCLUSION

Only the ST-G auto graft was able to reproduce the native size of the ACL footprint on the femoral side. None of the auto grafts could reproduce the size of the tibial ACL footprint. For clinical relevance, ST-G graft is recommended in order to reproduce the native size of the ACL in anatomical ACL reconstruction with auto graft.

ACL footprint size is correlated with the height and area of the lateral wall of femoral intercondylar notch

PURPOSE

The purpose of this study was to reveal the correlation between the size of the native anterior cruciate ligament (ACL) footprint and the size of the lateral wall of femoral intercondylar notch.

METHODS

Eighteen non-paired human cadaver knees were used. All soft tissues around the knee were resected except the ACL. The ACL was cut in the middle, and the femoral bone was cut at the most proximal point of the femoral notch. The ACL was carefully dissected, and the periphery of the ACL insertion site was outlined on both the femoral and tibial sides. An accurate lateral view of the femoral condyle and the tibial plateau was photographed with a digital camera, and the images were downloaded to a personal computer. The size of the femoral and tibial ACL footprints, length of Blumensaat's line, and the height and area of the lateral wall of femoral intercondylar notch were measured with Image J software (National Institution of Health).

RESULTS

The sizes of the native femoral and tibial ACL footprints were 84 ± 25.3 and 144.7 ± 35.9 mm(2), respectively. The length of Blumensaat's line and the height and area of the lateral wall of femoral intercondylar notch were 29.4 ± 2.8 mm, 17.1 ± 2.7 mm, and 392.4 ± 86 mm(2), respectively. Both the height and the area of the lateral wall of femoral intercondylar notch were significantly correlated with the size of the ACL footprint on both the femoral and tibial sides.

CONCLUSION

For clinical relevance, the height and area of the lateral wall of femoral intercondylar notch can be a predictor of native ACL size prior to surgery. However, the length of Blumensaat's line showed no significant correlation with native ACL size.

Effect of posterolateral bundle graft fixation angles on graft tension curves and load sharing in double-bundle anterior cruciate ligament reconstruction using a transtibial drilling technique

PURPOSE

To evaluate the effect of posterolateral bundle (PLB) graft fixation angles on graft tension curves and load sharing between the anteromedial bundle (AMB) and the PLB in double-bundle anterior cruciate ligament (ACL) reconstruction.

METHODS

Twenty-four patients who underwent double-bundle ACL reconstruction were included in this study. AMB and PLB were provisionally fixed to a graft tensioning system during surgery. The graft fixation settings were as follows: (1) AMB at 20° and PLB at 0° (A20P0), (2) AMB at 20° and PLB at 20° (A20P20), and (3) AMB at 20° and PLB at 45° (A20P45). Bundle tension was recorded during knee flexion-extension and in response to anterior or rotatory loads. A pivot-shift test, as well as factors affecting the residual pivot-shift, was also evaluated.

RESULTS

A20P45 created reciprocal tension curves and load sharing, in which the tension in both bundles was equivalent during flexion-extension and during each loading test at 30°. In A20P0, the tension of the AMB was constantly higher than that of the PLB. Seven patients showed grade 1 pivot-shift phenomenon in A20P0, whereas no patient showed a positive pivot-shift at other settings. Larger tension reduction of the PLB between 0° and 30° and smaller load sharing of the PLB were significant factors affecting residual pivot-shift.

CONCLUSIONS

In double-bundle ACL reconstruction, fixation of the AMB at 20° and the PLB at 45° created reciprocal tension curves and load sharing between the bundles. Fixation of the AMB at 20° and the PLB at 0° led to insufficient tension in the PLB, resulting in a residual pivot-shift phenomenon in 7 of 24 patients.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Eminence-based medicine versus evidence-based medicine: is anterior cruciate ligament reconstruction optimally performed with the double-bundle technique?

The anterior cruciate ligament (ACL) comprises 2 distinct bands or bundles-the anteromedial bundle, which is tighter in flexion, and the posterolateral bundle, which is tighter in extension. Traditional ACL reconstruction uses 1 graft. A new technique, known as the double-bundle technique, uses 2 tendon grafts to more closely approximate normal anatomy. Because the medical literature does not provide a definitive answer as to which reconstruction method is better, we surveyed 500 experts in sports medicine in a previous study to determine whether they agreed with the statement "ACL reconstruction is optimally performed with the double-bundle technique." Respondents were inclined to answer "This statement is probably false." Our article interprets the expert responses by reviewing the basic and clinical sciences implicit in the question and reviewing the literature regarding outcomes. We found that double-bundle ACL reconstruction is theoretically appealing, but evidence proving that it improves clinical outcomes is unavailable. High-quality studies are under way on the topic, which may provide a definitive answer. However, until such data are available, the expert consensus from our survey was that the double-bundle technique is not necessarily the optimal approach.

Double-bundle versus single-bundle reconstruction for anterior cruciate ligament rupture in adults

BACKGROUND

Arthroscopic reconstruction for anterior cruciate ligament rupture is a common orthopaedic procedure. One area of controversy is whether the method of double-bundle reconstruction, which represents the 'more anatomical' approach, gives improved outcomes compared with the more traditional single-bundle reconstruction.

OBJECTIVES

To assess the effects of double-bundle versus single-bundle for anterior cruciate ligament reconstruction in adults with anterior cruciate ligament deficiency.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (to February 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 2), MEDLINE (1966 to February week 3 2012) and EMBASE (1980 to 2012 Week 8). We also searched trial registers, conference proceedings, and contacted authors where necessary.

SELECTION CRITERIA

Randomised and quasi-randomised controlled clinical trials comparing double-bundle versus single-bundle reconstruction for anterior cruciate ligament (ACL) rupture in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected articles, assessed risk of bias and extracted data. We contacted investigators to obtain missing information. Where appropriate, results of comparable studies were pooled.

MAIN RESULTS

Seventeen trials were included. These involved 1433 people, mostly young physically active adults. All included trials had methodological weaknesses and were at risk of bias, notably selection bias from inadequate or lack of allocation concealment. Data for pooling individual outcomes were available for a maximum of nine trials and 54% of participants.There were no statistically or clinically significant differences between double-bundle and single-bundle reconstruction in the subjective functional knee scores (subjective IKDC score, Tegner activity score, Lysholm score) in the intermediate (six months up to two years since surgery) or long term (two to five years from surgery). For example, the long term results for the Lysholm score (0 to 100: best score) were: mean difference (MD) 0.12, 95% confidence interval (CI) -1.50 to 1.75; 5 trials, 263 participants). The only trial reporting on long term knee pain found no statistically significant differences between the two groups. There were no significant differences between the two groups in adverse effects and complications (e.g. infection reported by nine trials (7/285 versus 7/393; risk ratio (RR) 1.14, 95% CI 0.46 to 2.81); graft failure reported by six trials (1/169 versus 4/185; RR 0.45; 95% CI 0.07 to 2.90).Limited data from five trials found a better return to pre-injury level of activity after double-bundle reconstruction (147/162 versus 208/255; RR 1.15, 95% CI 1.07 to 1.25). At long term follow-up, there were statistically significant differences in favour of double-bundle reconstruction for IKDC knee examination (normal or nearly normal categories: 325/344 versus 386/429; RR 1.05, 95% CI 1.01 to 1.08; 9 trials), knee stability measured with KT-1000 arthrometer (MD -0.74 mm, 95% CI -1.10 to -0.37; 5 trials, 363 participants) and rotational knee stability tested by the pivot-shift test (normal or nearly normal categories: 293/298 versus 382/415; RR 1.06, 95% CI 1.02 to 1.09; 9 trials). There were also statistically significant differences in favour of double-bundle reconstruction for newly occurring meniscal injury (9/240 versus 24/358; RR 0.46, 95% CI 0.23 to 0.92; 6 trials) and traumatic ACL rupture (1/120 versus 8/149; RR 0.17, 95% CI 0.03 to 0.96; 3 trials). There were no statistically significant differences found between the two groups in range of motion (flexion and extension) deficits.

AUTHORS' CONCLUSIONS

There is insufficient evidence to determine the relative effectiveness of double-bundle and single-bundle reconstruction for anterior cruciate ligament rupture in adults, although there is limited evidence that double-bundle ACL reconstruction has some superior results in objective measurements of knee stability and protection against repeat ACL rupture or a new meniscal injury. High quality, large and appropriately reported randomised controlled trials of double-bundle versus single-bundle reconstruction for anterior cruciate ligament rupture in adults appear justified.

Anatomical evaluation of the rectus femoris tendon and its related structures

PURPOSE

The purpose of this study was to evaluate the anatomical structure of the quadriceps tendon in detail for use as an anterior cruciate ligament (ACL) graft tendon.

MATERIALS AND METHODS

Sixteen cadaveric knees with an average age of 78.8 were used. After careful dissection of skin and fascia, the muscle structure of each quadriceps was evaluated. In particular, the rectus femoris (RF) tendon was measured at its widest and narrowest width, the distance between widest or narrowest point and the proximal end of the patella, and the length.

RESULTS

The quadriceps tendon consisted of three layers. At the surface layer, the RF tendon existed mostly independently. The middle layer consisted of the vastus lateralis (VL) and medialis (VM) tendons. The deep layer consisted of the vastus intermedius (VI) tendon. The VL and VI tendons overlapped and were firmly connected, constituting the strength and size of the quadriceps. The narrowest width of the RF was 15.3 mm, and the narrowest point existed 4.8 mm proximal to the upper end of the patella. The average length of the RF was 27.3 cm.

CONCLUSION

If the RF tendon only is used as an ACL graft, surgeons should be cautious of the fact that the narrowest point of the RF tendon is located close to the patella. The entire quadriceps tendon is big enough to be used as an ACL graft. However, since the direction of the VL and VI tendons is different, the suitability of the quadriceps tendon as an ACL graft is questionable.

Anterior cruciate ligament reconstruction in a patient with Athetoid cerebral palsy: a case report

Recent years have seen ACL reconstruction performed in a broad range of patients, regardless of age, sex or occupation, thanks to great advances in surgical techniques, instrumentation and the basic research. Favorable results have been reported; however, we have not been able to locate any reports describing ACL reconstruction in patients with athetoid cerebral palsy.

We present herein a previously unreported anterior cruciate ligament (ACL) reconstruction performed in a patient with athetoid cerebral palsy. The patient was a 25-year-old woman with level II athetoid cerebral palsy according to the Gross Motor Function Classification System. She initially injured her right knee after falling off a bicycle. Two years later, she again experienced right-knee pain and a feeling of instability. A right-knee ACL tear and avulsion fracture was diagnosed upon physical examination and confirmed with magnetic resonance imaging (MRI) and X-ray examination at that time. An ACL reconstruction using an autologous hamstring double-bundle graft was performed for recurrent instability nine years after the initial injury. Cast immobilization was provided for 3 weeks following surgery and knee extension was restricted for 3 months with the functional ACL brace to prevent hyperextension due to involuntary movement. Partial weight-bearing was started 1 week postoperatively, with full weight-bearing after 4 weeks. The anterior drawer stress radiography showed a 63% anterior displacement of the involved tibia on the femur six months following the surgery, while the contralateral knee demonstrated a 60% anterior displacement of the tibia. The functional ACL functional brace was then removed. A second-look arthroscopy was performed 13 months after the ACL reconstruction, and both the anteromedial and posterolateral bundles were in excellent position as per Kondo’s criteria. The Lachman and pivot shift test performed under anesthesia were also negative. An anterior drawer stress radiography of the involved knee at 36 months following surgery showed a 61% anterior translation of the tibia. The preoperative symptoms of instability resolved and the patient expressed a high degree of satisfaction with the result of her surgery.

The function of the human anterior cruciate ligament and analysis of single- and double-bundle graft reconstructions

CONTEXT

There exists controversy on the ability of a single or double anterior cruciate ligament graft technique to restore anterior cruciate ligament function. This article examines the published experimental and clinical data supporting these surgical procedures in the ability to restore knee stability.

EVIDENCE ACQUISITION

An analysis of anterior cruciate ligament function and single- and double-graft reconstructions defined by selected biomechanical, robotic, kinematic, anatomical, and clinical studies.

RESULTS

The anterior cruciate ligament resists the combined motions of anterior tibial translation and internal tibial rotation, which defines the concept of rotational stability. This function prevents anterior tibial subluxation of the lateral and medial tibiofemoral compartments that accounts for the pivot-shift phenomena. The placement of single anterior cruciate ligament grafts high and proximal at the femoral attachment and posterior at the tibial attachment results in a vertical graft orientation. This graft placement results in a limited ability to provide rotational stability and is inferior when compared to a double-bundle graft procedure. Studies show that a more oblique single-graft orientation, in the sagittal and coronal plane, achieved from a central anatomic femoral and tibial location provides rotational stability similar to a double-bundle anterior cruciate ligament graft.

CONCLUSION

There exists insufficient experimental and clinical data to recommend the more complex double-bundle anterior cruciate ligament graft technique over a well-placed central anatomic single graft in terms of restoring knee rotational stability. Meticulous surgical technique for anterior cruciate ligament graft placement is necessary to avoid failure.

Failure of anterior cruciate ligament reconstruction

Failure after anterior cruciate ligament reconstruction is a potentially devastating event that affects a predominantly young and active population. This review article provides a comprehensive analysis of the potential causes of failure, including graft failure, loss of motion, extensor mechanism dysfunction, osteoarthritis, and infection. The etiology of graft failure is discussed in detail with a particular emphasis on failure after anatomic anterior cruciate ligament reconstruction.

Single-bundle versus double-bundle anterior cruciate ligament reconstruction: an up-to-date meta-analysis

PURPOSE

The aim of this meta-analysis was to compare the results of arthroscopic single-bundle and double-bundle anterior cruciate ligament (ACL) reconstruction.

METHODS

We systematically searched electronic databases to identify randomised controlled trials (RCTs) in which arthroscopic single-bundle was compared with double-bundle for ACL reconstruction. The search strategy followed the requirements of the Cochrane Library Handbook. The outcomes of these studies were analysed in terms of graft failures, Lysholm score, negative pivot-shift test, KT1000 arthrometer measurements, knee extensor and flexor peak torques, knee extension and flexion deficit, and subjective and objective International Knee Documentation Committee (IKDC) final score. Methodological quality was assessed and data were extracted independently. Standard mean difference (SMD) or odds ratio (OR) with 95 % confidence interval (CI) was calculated by a fixed effects or random effects model. Heterogeneity across the studies was assessed with the I-square and chi-square statistic. Forest plots were also generated.

RESULTS

We identified 17 RCTs comprising 1,381 patients who were treated by arthroscopic single-bundle versus double-bundle ACL reconstruction. The results of meta-analysis of these studies showed that arthroscopic double-bundle reconstruction was associated with a lower risk of graft failures (P=0.002) and a lower rate of positive pivot-shift test (P<0.0001). Compared with single-bundle reconstruction, double-bundle reconstruction had a lower KT1000 arthrometer measurement (P<0.00001), a lower knee extension deficit (P=0.006) and a higher subjective IKDC score (P=0.03). There was no statistically significant difference between single-bundle and double-bundle reconstruction in Lysholm score (P=0.91), knee extensor peak torques (P=0.97), knee flexor peak torques (P=0.96), knee flexion deficit (P=0.30) and objective IKDC score (P=0.18).

CONCLUSIONS

Considering the more favourable outcomes of graft failures, knee joint stability and knee joint function in double-bundle reconstruction, we concluded that arthroscopic double-bundle reconstruction should be considered as the primary treatment in ACL reconstruction.

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.

Effects of single-bundle and double-bundle ACL reconstruction on tibiofemoral compressive stresses and joint kinematics during simulated squatting

The purpose of this study was to compare tibiofemoral (TF) kinematics and TF compressive stresses between single bundle- (SB-) and double bundle-ACL reconstruction (DB-ACLR) during simulated squatting. Twelve matched pairs of fresh frozen cadaver knees were utilized. A simulated squat through 100° of knee flexion was performed in the ACL-intact joint. The ACL was transected and SB- and DB-ACLR procedures were performed in one knee of each pair. The squat was repeated. Knee kinematics were measured using a motion tracking system and the TF compressive forces were measured using thin film pressure sensors. The posterior shifts of the tibia for SB- and DB-ACLR knees were significantly greater than the ACL-intact condition for knee flexion angles 0° to 40° (p<.05). However, there was no difference between the SB- and DB-ACLR knees at any flexion angle (0° to 100°; p=.37). SB- and DB-ACLR knees had greater IE rotation than intact knees from 90° through 50° of flexion (p<.05), but not between 40° and full extension. There was no difference between SB- and DB-ACLR knees (p=.68). The TF compressive stresses of the DB-ACLR were significantly lower than intact for all angles except 10° (p=.06), whereas SB-ACLR knees did not differ from intact at flexion angles between 30° and 50° (p>.32). There were no significant differences between the two reconstruction conditions (p=.74). This study showed that there was no difference in the TF kinematics or compressive stresses between SB- and DB-ACLR, and only minor differences when compared to the intact state.

Individualized anterior cruciate ligament surgery: a prospective study comparing anatomic single- and double-bundle reconstruction

BACKGROUND

Reconstruction of the anterior cruciate ligament (ACL) has become a commonly performed procedure. However, biomechanical studies have demonstrated that conventional single-bundle ACL reconstruction techniques are only successful in limiting anterior tibial translation but less effective for restoring rotatory laxity.

PURPOSE

This study aimed to compare the results of single- and double-bundle ACL reconstruction using an anatomic technique, individualized based on the patient's native ACL size. The authors hypothesized that there would be no difference between the results of anatomic single-bundle (ASB) and anatomic double-bundle (ADB) reconstruction when the surgical technique is individualized.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Depending on intraoperative measurements of the ACL insertion site size, patients were selected for either ASB (n = 32) or ADB (n = 69) ACL reconstruction. In all groups, hamstring tendons autograft was used with suspensory fixation on the femoral side and bioabsorbable interference screw fixation on the tibial side. The outcomes were evaluated by an independent blinded observer using the Lysholm score, subjective International Knee Documentation Committee (IKDC) form, KT-1000 arthrometer for anteroposterior stability, and pivot-shift test for rotational stability. The average follow-up was 30 months (range, 26-34 months). There were no statistically significant differences in the baseline demographics of the 2 groups.

RESULTS

There was no significant difference between the ADB and ASB groups for Lysholm score (93.9 vs 93.5), subjective IKDC score (93.3 vs 93.1), anterior tibial translation (1.5- vs 1.6-mm side-to-side difference), and pivot shift (92% vs 90% with negative pivot-shift examination).

CONCLUSION

Anatomic double-bundle reconstruction is not superior to anatomic single-bundle reconstruction when an individualized ACL reconstruction technique is used.

Guideline on anterior cruciate ligament injury

The Dutch Orthopaedic Association has a long tradition of development of practical clinical guidelines. Here we present the recommendations from the multidisciplinary clinical guideline working group for anterior cruciate ligament injury. The following 8 clinical questions were formulated by a steering group of the Dutch Orthopaedic Association. What is the role of physical examination and additional diagnostic tools? Which patient-related outcome measures should be used? What are the relevant parameters that influence the indication for an ACL reconstruction? Which findings or complaints are predictive of a bad result of an ACL injury treatment? What is the optimal timing for surgery for an ACL injury? What is the outcome of different conservative treatment modalities? Which kind of graft gives the best result in an ACL reconstruction? What is the optimal postoperative treatment concerning rehabilitation, resumption of sports, and physiotherapy? These 8 questions were answered and recommendations were made, using the "Appraisal of Guidelines for Research and Evaluation" instrument. This instrument seeks to improve the quality and effectiveness of clinical practical guidelines by establishing a shared framework to develop, report, and assess. The steering group has also developed 7 internal indicators to aid in measuring and enhancing the quality of the treatment of patients with an ACL injury, for use in a hospital or practice.

The evolution of anatomic anterior cruciate ligament reconstruction

Anterior cruciate ligament reconstruction has evolved significantly since the early 1900's, back when an emphasis was placed on repair and not reconstruction. Over the past century, the technique has evolved from intra-articular non anatomic reconstruction, to extra articular reconstruction, back to intra articular (performed arthroscopically), to now, the advent of anatomic insertion site restoration. This review will aim to illustrate the changes that have occurred, describing the rational for this process, based upon anatomical, radiological, biomechanical and clinical studies, all of which have aimed to improve patient function following ACL injury.

Clinical comparison of two suspensory fixation devices for anatomic double-bundle anterior cruciate ligament reconstruction

PURPOSE

The aim of this study was to compare the operation time required and the clinical outcome 2 years postoperatively, after anatomic double-bundle ACL reconstructions using hamstring tendon grafts fixed with either the EndoButton-CL-BTB(®) (ECL-BTB) or the EndoButton-CL(®) (ECL).

METHODS

Forty-six patients, who underwent anatomic double-bundle ACL reconstruction, were non-randomly divided into 2 groups. Patients with a combined ligament injury or complete meniscal tear were excluded from this study. In group I, an ECL was used with 23 patients. In group II, an ECL-BTB was used with the remaining 23 patients. In groups I and II, the ECL or ECL-BTB was attached to the femoral ends of the hamstring tendon autografts. In both groups, a polyester tape was connected in series with the tibial ends of the grafts. The patients were examined with standard clinical evaluations at 2 years after surgery.

RESULTS

The operation time in group II was significantly shorter than that in group I (P = 0.0459). Concerning the intra- and postoperative complications, there were no serious complications in either group. No significant differences were found between the 2 groups in terms of knee laxity measurements, the peak muscle torque of quadriceps and hamstrings, the Lysholm score and the IKDC evaluation.

CONCLUSIONS

This study demonstrated that the usage of the ECL-BTB for graft preparation significantly shortens the total operation time in comparison with the ECL and that there were no significant differences in the 2-year clinical outcome and the intra- and postoperative complications between the 2 graft preparation procedures of the anatomic double-bundle ACL reconstruction. The ECL-BTB can be an alternative device for the hamstring tendon graft in double-bundle ACL reconstruction.

LEVEL OF EVIDENCE

Prospective comparative cohort study, Level II.

Double-bundle versus single-bundle anterior cruciate ligament reconstruction: a prospective randomized study with 5-year results

BACKGROUND

Surgical technique is essential in anterior cruciate ligament (ACL) reconstruction.

PURPOSE

This randomized 5-year study tested the hypothesis that double-bundle ACL reconstruction with hamstring autografts and aperture screw fixation has fewer graft ruptures and rates of osteoarthritis (OA) and better stability than single-bundle reconstruction.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Ninety patients were randomized: double-bundle ACL reconstruction with bioabsorbable screw fixation (DB group; n = 30), single-bundle ACL reconstruction with bioabsorbable screw fixation (SBB group; n = 30), and single-bundle ACL reconstruction with metallic screw fixation (SBM group; n = 30). The following evaluation methods were used: clinical examination, KT-1000 arthrometer measurement, and International Knee Documentation Committee (IKDC) and Lysholm knee scores. Additionally, radiographic evaluation was made by a musculoskeletal radiologist who was unaware of the patients' clinical and surgical data. A single orthopaedic surgeon performed all the operations, and clinical follow-up assessments were made in a blinded manner by an independent examiner.

RESULTS

Preoperatively, there were no differences between the groups. Eleven patients (7 in the SBB group, 3 in the SBM group, and 1 in the DB group) had a graft failure during the follow-up and went on to ACL revision surgery (P < .043). Of the remaining 79 patients, a 5-year follow-up was performed for 65 patients (20 in the DB group, 21 in the SBB group, and 24 in the SBM group) who had their grafts intact. At 5 years, there was no statistically significant difference in the pivot-shift or KT-1000 arthrometer tests. In the DB group, 20% of the patients had OA in the medial femorotibial compartment and 10% in the lateral compartment, while the corresponding figures were 33% and 18% in the single-bundle groups, again an insignificant finding. Further, no significant group differences were found in the knee scores.

CONCLUSION

The double-bundle surgery resulted in significantly fewer graft failures and subsequent revision ACL surgery than the single-bundle surgeries during the 5-year follow-up. Knee stability and OA rates were similar at 5 years. In view of the size of the groups, some caution should be exercised when interpreting the lack of difference in the secondary outcomes.

MRI of double-bundle ACL reconstruction: evaluation of graft findings

OBJECTIVE

To demonstrate the magnetic resonance imaging (MRI) findings of double-bundle (DB) anterior cruciate ligament (ACL) reconstruction grafts.

MATERIALS AND METHODS

Sixty-six patients with DB ACL reconstruction were evaluated with MRI 2 years postoperatively. Graft thickness was measured separately by two musculoskeletal radiologists. The MRI findings of graft disruption, signal intensity (SI) changes, cystic degeneration, arthrofibrosis, and impingement were analyzed. The statistical significance of the association between MRI findings was calculated.

RESULTS

The mean anteromedial (AM) graft thickness was reduced 9% and the mean posterolateral (PL) graft thickness was reduced 18% from the original graft thickness. Disruption was seen in 3% of AM grafts and 6% of PL grafts and a partial tear in 8 and 23%, respectively. Both grafts were disrupted in 3% of patients. Increased SI was seen in 14% of intact AM grafts and in 60% of partially torn AM grafts (p = 0.032). In PL grafts the increased SI was seen in 51% of the intact grafts and in 93% of the partially torn grafts (p = 0.005). Cystic degeneration was seen in 8% of AM grafts and in 5% of PL grafts. Diffuse arthrofibrosis was seen in 5% of patients and a localized cyclops lesion in 3% of patients. Impingement of the AM graft was seen in 8% of patients.

CONCLUSION

Both grafts were disrupted in 3% of patients. Also, the frequencies of other complications were low. The use of orthogonal sequences in the evaluation of the PL graft SI seems to cause volume-averaging artefacts.

Pivot shift as an outcome measure for ACL reconstruction: a systematic review

PURPOSE

To identify and evaluate the evidence for the pivot shift test as an outcome measure following ACL reconstruction. Achieving rotatory control of the knee post anterior cruciate ligament (ACL) reconstruction has been shown to increase patient satisfaction, decrease functional instability and potentially delay the development of osteoarthritis. The pivot shift is able to assess this rotatory component of knee laxity and appears to have the potential to become a benchmark in gauging the success of ACL surgery. Multiple confounding factors and discrepancies in performing the maneuver itself however put its usefulness in question. Thus, the literature was reviewed to assess whether the pivot shift was able to correlate with final functional outcomes.

METHODS

Two reviewers searched two databases (MEDLINE and EMBASE) for randomized control trials that involved anterior cruciate ligament reconstruction in the last 5 years. All non-clinical studies were excluded. A quality assessment of the included studies was performed using the Jadad scale by a reviewer. The number of studies using the Pivot Shift Test as well as the test's relationship with functional outcome was evaluated.

RESULTS

The literature search yielded 274 studies, of which 65 papers were included. The average Jadad quality score for papers reporting pivot shift as an outcome measure was 2.4, with the most frequent score being 3. Forty seven of 65 studies described the Pivot Shift Test as an outcome measure following ACL reconstruction. Of the 47 studies that included pivot shift as an outcome measure, 40 (85%) correlated with the final functional outcomes.

CONCLUSION

The pivot shift test is an important test following ACL reconstruction, and it correlates with functional outcomes.