Anatomic Double-bundle Anterior Cruciate Ligament Reconstruction Research Articles

Outcome of anatomical double-bundle ACL reconstruction using hamstring tendons via an outside-in approach

To evaluate the clinical outcome of anatomical double-bundle anterior cruciate ligament (ACL) reconstruction using multistranded hamstring tendons via an outside-in approach. One hundred and twenty-one patients (mean age 28±10years) who underwent ACL reconstruction were examined. Using an outside-in femoral drill guide, an upper femoral tunnel for the anteromedial (AM) graft was created just below the superior articular cartilage margin of the medial wall of the lateral condyle through a small incision. A lower femoral tunnel for the posterolateral (PL) graft was drilled in the centre of the inferior-posterior half of the attachment area behind the resident's ridge in the same manner. Two tibial tunnels were created at the centre of the AM and PL bundle footprints of a normal ACL. Patients were evaluated at 24months postoperatively. According to the IKDC form, 52 knees (43%) were graded as normal, 64 (53%) as nearly normal, 1 (1%) as abnormal and 4 (3%) as graft rupture due to re-injury. Loss of knee extension of <5° was observed in one patient (1%). Among 111 patients who were directly evaluated, none showed loss of flexion of <5°. Lachman sign was negative in 103 patients (93%), while the pivot shift test result was negative or equivalent to that of the contralateral healthy knee in 103 patients (93%). The mean side-to-side difference in anterior laxity at manual maximum force with the KT-2000 arthrometer(®) was 0.9±1.1mm, and 94% of patients showed a range between -1 and +2mm. The anatomical double-bundle outside-in ACL reconstruction provided a satisfactory short-term outcome. Case series, Level IV.

THE EFFECT OF EDUCATIONAL LECTURE ON REDUCING REINJURY AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

BackgroundAlthough anterior cruciate ligament (ACL) injury prevention programs have been published, little is known about ACL reinjury prevention after ACL reconstruction. On the other hand, we have held educational lectures...

Signal intensity on magnetic resonance imaging after allograft double-bundle anterior cruciate ligament reconstruction

To evaluate magnetic resonance imaging (MRI) graft signal intensity after allograft double-bundle (DB) anterior cruciate ligament (ACL) reconstruction and determine the relationship between signal intensity and time from surgery. Twenty-six patients with an intact graft on MRI after anatomic allograft DB ACL reconstruction up to 1year post-operatively were included. All subjects underwent post-operative MRI using a 1.5-T magnet. Sagittal proton density-weighted images (PDWI) and sagittal T2-weighted images (T2WI) were analysed. Using the region-of-interest (ROI) function on imaging software, the anteromedial (AM) and posterolateral (PL) bundles of the graft and the posterior cruciate ligament (PCL) were outlined. Mean signal intensity of the three ROIs were recorded as absolute signal intensity. Signal intensity (SI ratio) was calculated based on the signal intensity of the PCL. Correlation coefficients were calculated to determine the relationship between signal intensity and time from surgery. SI ratio of the PL bundle was higher than that of the AM bundle for both the PDWI (1.7±1.5 vs. 2.5±1.7, p<0.05) and T2WI (1.3±0.4 vs 1.6±0.6, p<0.05). There were weak correlations between AM SI ratio and time from surgery (r=0.38, p<0.05 on PDWI), and moderate correlations between PL SI ratio and time from surgery (r=0.43, p<0.05 on PDWI) (r=0.44, p<0.05 on T2WI). The PL bundle displayed increased signal intensity compared to the AM bundle and based on previous studies may indicate a longer healing process. Plain MRI may be useful to assess graft healing after ACL reconstruction. Retrospective case series, Level IV.

Anatomic double-bundle reconstruction of the anterior cruciate ligament: midterm results

PurposeThe aim of this study was to investigate the functional outcomes, knee stability, and patient's satisfaction after anatomic double-bundle anterior cruciate ligament (ACL) reconstruction using the three-portal technique.Patients and methodsA prospective case series study on 48 patients (24 were active athletes) with complete tear of the ACL was conducted. All patients underwent anatomic double-bundle ACL reconstruction. Participants were assessed with history taking, clinical examination, International Knee Documentation Committee (IKDC) score, Lysholm scale, and Tegner scale. All assessments were carried out preoperatively and repeated postoperatively every 6 months until a minimum of 2 years. Data were collected and analyzed to detect significant changes.ResultsImprovement was observed in the mean IKDC score from 68.1 to 93.5, in the Lysholm score from 73.8 to 95.5, and in the Tegner scale from 4 to 9.4. All patients showed negative Lachmann and anterior drawer tests at 24 months follow-up; only two (4.2%) patients showed slight glide (one positive), with overall patient satisfaction of 93.8%.ConclusionAnatomic double-bundle ACL reconstruction results in significant improvement in the clinical outcomes and knee stability, with 93.8% satisfaction and return to preinjury level of activity.

Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction Using In Situ Hamstring Graft With 4 Tunnels

A careful review of the literature suggests that a significant number of patients undergoing anterior cruciate ligament (ACL) reconstruction have less-than-optimal results. Although overall outcomes of ACL reconstruction are favorable, there remains considerable room for improvement. Anatomically, the ACL consists of 2 major functional bundles, the anteromedial bundle and the posterolateral bundle. Biomechanically, both bundles contribute significantly to the anterior and rotational stability of the knee. Therefore anatomic double-bundle ACL reconstruction techniques may further improve the outcomes in ACL surgery. This article presents a technique for arthroscopic double-bundle ACL reconstruction that includes the use of 2 femoral and 2 tibial tunnels to restore both the anteromedial and posterolateral bundles of the ACL with minimal hardware for fixation.

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

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. 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. 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. 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. II.

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.

Influence of tibial rotation on tibial tunnel position measurements using lateral fluoroscopy in anterior cruciate ligament reconstruction

The purpose of the current study was to evaluate the influence of internal and external knee rotation on tibial tunnel position measurements in anterior cruciate ligament reconstruction using the Amis and Jakob line. Anatomic double bundle ACL reconstruction was performed in seven cadaveric knees. Afterwards, the knees were CT scanned, and 3D CT models were established. Utilizing these models, strict lateral and radiographs with the knees in 5°, 10°, and 20° of internal as well as external rotation were established. Using these radiographs, the positions of the anteromedial (AM) and posterolateral (PL) tibial tunnels were measured using the Amis and Jacob line. The tunnel positions of the strict lateral were compared to the rotated radiographs. To assess the inter- and intraobserver reliability, two independent observers measured the tunnel positions, and one observer measured twice. Significant differences for the AM tunnel position were observed if more than 10° of external or 20° of internal rotation were applied. For the PL tunnel position, no significant differences were found between the strict lateral and the rotated radiographs. Inter- and intraobserver reliability was good. The accuracy of the Amis and Jakob line is dependent on the degree of knee rotation and the position of the measured tunnel. Therefore, when using the Amis and Jakob line to determine the tibial tunnel position during surgery, attention should be paid to rotational alignment of lateral radiographs. However, the maximum rotation tested in the present study (20°) showed only a difference in tunnel position of 3.3 % compared to optimal rotational alignment. Thus, in most cases, the effects of minor malrotation on tunnel position measurement should be of minimal clinical significance.

Accuracy of a computer-assisted planning and placement system for anatomical femoral tunnel positioning in anterior cruciate ligament reconstruction

Femoral tunnel positioning is a difficult, but important factor in successful anterior cruciate ligament (ACL) reconstruction. Computer navigation can improve the anatomical planning procedure besides the tunnel placement procedure. The accuracy of the computer-assisted femoral tunnel positioning method for anatomical double bundle ACL-reconstruction with a three-dimensional template was determined with respect to both aspects for AM and PL bundles in 12 cadaveric knees. The accuracy of the total tunnel positioning procedure was 2.7 mm (AM) and 3.2 mm (PL). These values consisted of the accuracies for planning (AM:2.9 mm; PL:3.2 mm) and for placement (about 0.4 mm). The template showed a systematic bias for the PL-position. The computer-assisted templating method showed high accuracy for tunnel placement and has promising capacity for application in anatomical tunnel planning. Improvement of the template will result in an accurate and robust navigation system for femoral tunnel positioning in ACL-reconstruction.

Intercondylar Roof Impingement After Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction in Patients With Knee Hyperextension

Background: Although an anatomically placed graft in anterior cruciate ligament (ACL) reconstruction is reported to have a low risk of roof impingement, which may cause deterioration of the graft or an extension deficit, the incidence of roof impingement by these grafts has not been evaluated in hyperextensible knees. Purpose: To evaluate the incidence of roof impingement by the native ACL in hyperextensible knees and to examine the risk of roof impingement by anatomic placement of the ACL graft in hyperextensible knees. Study Design: Controlled laboratory study. Methods: Twelve patients were selected for a hyperextensible knee group (group A), defined as having hyperextension of the knee of greater than 10°. Twelve patients were recruited to a normal extension knee group (group B) with normal extension of the knee of less than 5° of hyperextension. Magnetic resonance imaging (MRI) scans of the knee positioned in 30° of flexion and full extension were acquired from all patients. The shape of the native ACL at full extension was compared between the groups. A 3-dimensional (3D) bone model was created from the acquired 2D MRI scans. A virtual anatomic double-bundle ACL reconstruction in each patient and a virtual anatomic single-bundle reconstruction in the patients in group A were performed using the 3D MRI bone models. The volume of the overlap between the graft and roof was calculated to evaluate graft impingement in each instance. Results: The MRI scans showed posterior bowing of the native ACL in the group A knees. The simulated double-bundle ACL reconstruction showed that the overlapped volume was significantly greater in patients in group A than in patients in group B (P < .05). However, the overlap of the simulated single-bundle ACL reconstruction was significantly less than for the double-bundle ACL reconstruction (P < .05). Conclusion: To reduce the risk of roof impingement by the graft, single-bundle ACL reconstruction with the graft placed at the center of the footprint might be the better method for patients with a hyperextensible knee than an anatomic double-bundle ACL reconstruction. Clinical Relevance: It is recommended that surgeons cautiously consider roof impingement after anatomic double-bundle ACL reconstruction in patients with a hyperextensible knee.

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

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

A Prospective Randomized Study Of Anatomical Double-Bundle ACL Reconstruction Using Hamstring Versus Anatomical Rectangular Tunnel Reconstruction Using Bone-Patellar Tendon-Bone Graft

Our prospective randomized study shows that anatomical double-bundle ACL reconstruction using hamstring and anatomical rectangular tunnel ACL reconstruction using BTB achieve almost the same results, and that there are no adverse effects by BTB, such as anterior knee pain. Recently, more anatomical ACL reconstructions have been recommended to improve results of reconstruction. The Purpose of this study was to compare clinical results of anatomical double-bundle (DB) ACL reconstruction using hamstring tendons (HT) and those of anatomical rectangular tunnel (RT) ACL reconstruction using bone-patellar tendon-bone autograft (BTB). One hundred and eighty-nine knees received primary ACL reconstruction from 2007 to 2009 in our institute. Of these, DB-ACL reconstruction or RT-ACL reconstruction were randomly performed in skeletally mature cases. One hundred and fifty-six cases were followed more than two years and included in this study. These patients were clinically evaluated preoperatively, and at 3, 6, 9 months, 1 and 2 years after ACL reconstruction. Clinical evaluations were KT-1000 arthrometer, Lachman test, Pivot shift test, quadriceps and hamstring strength (Cybex). At final follow-up, Tegner activity score, Lysholm score and Knee injury and Osteoarthritis Outcome Score (KOOS) were also evaluated. Both DB-ACL reconstruction and RT-ACL reconstruction similarly improved knee laxity compared to before reconstruction. At 2 years after reconstruction, side-to side differences of KT-1000 arthrometer were 0.9 ± 1.0 mm and 0.8 ± 1.1 mm respectively. Regarding muscle strength, average quadriceps strength in the RT-ACL reconstruction group in early stages (within 9 months) was weaker, but there were no significant differences at one year or later. There were no significant difference among Lysholm, Tegner activity score and KOOS at final follow-up. Our data suggest that both DB- and RT-ACL reconstruction achieve almost the same results. Although we hypothesized that ACL reconstruction with BTB has more knee symptoms, such as anterior knee pain and kneeling pain, especially in female patients, these adverse effects were not detected by KOOS.

Effect of Medial-Lateral Position of the Tibial Anteromedial Bundle Tunnel on Knee Biomechanics

Effect of Medial-Lateral Position of the Tibial Anteromedial Bundle Tunnel on Knee Biomechanics

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

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. 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. 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). 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. IV.

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

BackgroundThe data available from the previously reported clinical studies remains insufficient concerning the hamstring graft preparation in double-bundle anterior cruciate ligament (ACL) reconstruction. ObjectiveTo 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. MethodsA 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 6mm, 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 6mm 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 2years after surgery. ResultsThe postoperative side-to-side anterior laxity averaged 1.3mm 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. ConclusionThere 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 evidenceLevel II; prospective comparative study.

Tunnel Widening After Anatomic Double-Bundle and Mid-Position Single-Bundle Anterior Cruciate Ligament Reconstruction

The purpose of this study was to compare the amount of postoperative bone tunnel enlargement after anatomic double-bundle (DB) and single-bundle (SB) anterior cruciate ligament (ACL) reconstruction 6 to 8 months after surgery. Twenty-one consecutive patients undergoing anatomic 4-tunnel DB ACL reconstruction and 24 patients undergoing anatomic 2-tunnel SB ACL reconstruction were included in this study. In both groups a hybrid fixation technique with interference screw and extracortical fixation at the tibia and an extracortical fixation technique at the femur were used. Magnetic resonance imaging was performed on the second postoperative day and at a mean of 8 months' follow-up (range, 6.8 to 8.3 months) to assess intraoperative and postoperative bone tunnel enlargement. Tunnel widening was determined in different planes by digitally measuring the diameters of the bone tunnels. Tunnel position was measured and classified according to Harner etal. (femoral) and Stäubli etal. and Petersen etal. (tibial). Magnetic resonance imaging showed that all bone tunnels were anatomically placed within the area of the original ACL insertion zone. Compared with the intraoperative drill diameter, we observed only a slight increase in tunnel diameter in both groups on the second postoperative day. At 8 months postoperatively, significant bone tunnel widening occurred in all bone tunnels (P < .001). However, no significant differences were found between tunnel enlargement in the DB group and tunnel enlargement in the SB group (P > .05), either on the tibial side or on the femoral side. In 2 cases tibial tunnel communication was noted at follow-up. With the use of anatomic SB and DB ACL reconstruction techniques, the results of bone tunnel enlargement were comparable; no significant difference was observed between the tibial and femoral tunnels. Level III, prospective comparative study.

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

BackgroundIn 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.MethodsFirst, 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.ResultsThe 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.ConclusionsThe 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.

Anatomic Double-bundle Reconstruction Using Semitendinosus Tendon

For the surgical reconstruction of the anterior cruciate ligament (ACL), a severe challenge is the striking differences in diameter between midsubstance and insertion of the ACL. Both, femoral origin and tibial insertion have an approximately 3 times larger area when compared to the midsubstance. In patients with large insertion sides a single-bundle ACL reconstruction can probably only reflect a compromise restoring only part of the ACL function. Here, a double-bundle (DB) reconstruction can be a good alternative as reconstruction strategy to restore as much of the origin and insertion. This reconstruction can replicate both, anterior and rotational stability of the knee. A well-taken downside of DB reconstruction is the high risk of femoral and tibial tunnel placement. Purpose of the paper is therefore to illustrate the strategy and principles of ACL DB reconstruction with specific aim of providing pitfalls and solutions. This paper describes the technique for an anatomic DB ACL reconstruction using the semitendinosus tendon. In a medial portal approach with a single medial portal, 2 femoral tunnels are located for anteronedial and posterolateral bundle using anatomic femoral aimers. Two tibial tunnels are positioned with regard to the anterior horn of the lateral meniscus with a tibial DB aimer. Using a standardized technique, pitfalls can be avoided and DB reconstruction can be a column in the ACL therapy algorithm.

Biomechanical Comparison of Anatomic Single- and Double-Bundle Anterior Cruciate Ligament Reconstructions

Background: Arthroscopic identification of the anteromedial (AM) and posterolateral (PL) bundle locations of the anterior cruciate ligament (ACL) has facilitated an improved quantitative description of ACL anatomy. Few studies have directly compared the biomechanical laxity of anatomic single-bundle (SB) versus anatomic double-bundle (DB) ACL reconstruction techniques based on precise anatomic descriptions. Hypothesis: Anatomic tunnel positioning for SB and DB reconstructions would produce comparable anterior-posterior and rotatory knee laxity. Study Design: Controlled laboratory study. Methods: Nine matched pairs of cadaveric knees were evaluated for the kinematics of intact, ACL-deficient, and either anatomic SB or anatomic DB ACL-reconstructed knees. Reconstruction tunnels were placed either centrally in the ACL footprint or within the AM and PL footprints. A 6 degrees of freedom robotic system was used to assess knee laxity with an 88-N anterior tibial load and a simulated pivot-shift test of combined 10-N·m valgus and 5-N·m internal tibial torques. Rotational motion was measured with internal and external torques of 5 N·m along with varus and valgus torques of 10 N·m. One-sample and 2-sample independent t tests were used to compare between groups (P < .05). Results: No significant differences were found between anatomic SB and DB reconstruction groups during anterior tibial loading. Anterior tibial translations during simulated pivot shift had no significant differences between anatomic reconstruction groups. Tibial rotation for internal/external and varus/valgus torques showed no significant differences between anatomic reconstructions, with the exception of small (<3°) but statistically significant differences in internal rotation at 20° and 30° of flexion. Despite the similar behavior between the 2 anatomic reconstruction groups, neither technique was able to reproduce the intact state during an anterior tibial load. Conclusion: No significant differences in anterior translation were found between the anatomic SB and anatomic DB ACL reconstructions for simulated pivot shift or anterior tibial loading. Clinical Relevance: Although significant differences between reconstructions were observed for internal rotation, the small magnitude of these differences (<3°) may not have clinical significance.

Double-bundle ACL reconstruction: Novice surgeons utilizing computer-assisted navigation versus experienced surgeons

Purpose: Anatomic double-bundle ACL reconstruction presents a unique technical challenge for surgeons, requiring precise placement of multiple tunnels in a relatively small area. As the necessity of anatomic reconstruction has been stressed throughout the literature, developing a method to consistently improve the accuracy and precision of tunnel placement is essential. We aimed to investigate whether computer-assisted navigation allows novice surgeons to place double-bundle ACL tunnels with a similar degree of accuracy to experienced surgeons operating without computer assistance.Methods: A novice surgeon group comprising three medical students performed double-bundle ACL reconstruction using passive computer-assisted navigation in 11 cadaver knees. Their individual results were compared to those of three experienced orthopaedic surgeons, each performing the identical procedure without the use of computer-assisted navigation in 9 cadaver knees.Results and conclusion: There were no significant differences in placement of either the AM or PL tunnels on the tibial plateau between the novice surgeons using computer-assisted navigation and the experienced surgeons. However, on the lateral femoral condyle, the novice surgeons placed the AM and PL tunnels significantly more anterior along Blumensaat’s line, on average, compared to the experienced surgeons.