Anatomic Arthroscopic Anterior Cruciate Ligament Reconstruction Using Bone–Patellar Tendon–Bone Autograft

Transtibial versus anteromedial portal anterior cruciate ligament reconstruction using soft-tissue graft and expandable fixation

PURPOSE

To compare clinical outcomes between transtibial drilling and anteromedial portal techniques for anterior cruciate ligament (ACL) reconstruction using soft-tissue grafts secured with expandable fixation.

METHODS

Patients undergoing soft-tissue ACL reconstruction using expandable fixation between 2007 and 2011 were reviewed for inclusion in this study. Revision ACL cases were excluded. All surgeries were performed by 1 of 2 sports medicine fellowship-trained surgeons (T.S.D., K.D.M.). A total of 128 patients (67 comprising transtibial cohort and 61 comprising anteromedial portal cohort) had a minimum of 24 months' follow-up (mean, 27 months) and met the inclusion criteria. The patients were divided into 2 groups based on the method used for creation of the femoral tunnel. At final follow-up, outcomes were assessed with KT-1000 (MEDmetric, San Diego, CA) measurements, as well as International Knee Documentation Committee, Lysholm, and Tegner scores. Data were screened for normality and skew before use of parametric statistics and were transformed if necessary. Data were analyzed by 1-way analysis of variance with post hoc paired comparisons using the Bonferroni approximation.

RESULTS

No differences in demographic characteristics were observed between the 2 groups. There was no significant difference in postoperative KT-1000 measurements between the 2 cohorts (1.571 ± 0.2275 mm in transtibial cohort [n = 35] and 1.246 ± 0.09249 mm in anteromedial cohort [n = 61], P = .1259). A significant improvement in International Knee Documentation Committee scores was observed in the anteromedial cohort, increasing from 41 ± 16 to 89 ± 7.4 (mean ± SD) (P < .0001). Similar changes were observed for the Lysholm score. There was no significant difference between cohorts for any postoperative scores measured (P > .2).

CONCLUSIONS

Our data show comparable KT-1000 measurements for both anteromedial and transtibial femoral drilling techniques when using a soft-tissue graft with expandable fixation.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Femoral graft bending angle and femoral tunnel geometry of transportal and outside-in techniques in anterior cruciate ligament reconstruction: an in vivo 3-dimensional computed tomography analysis

PURPOSE

To compare femoral graft bending angles and femoral tunnel geometries between the transportal (TP) and outside-in (OI) techniques after anatomic double-bundle (DB) anterior cruciate ligament (ACL) reconstruction.

METHODS

Thirty-nine patients underwent DB ACL reconstruction with the TP and OI techniques. They were randomized on the day of surgery to either the TP group (group I, 21 cases) or the OI group (group II, 18 cases). Femoral graft bending angle, femoral tunnel geometry, posterior wall breakage, and tunnel communication were assessed by computed tomography imaging with OsiriX imaging software (Pixmeo, Geneva, Switzerland).

RESULTS

The mean anteromedial (AM) and posterolateral (PL) femoral graft bending angles of group II (97.3° ± 8.3° and 97.4° ± 8.6°, respectively) were significantly more acute than those of group I (108.2° ± 8.4° and 109.9° ± 8.8°, respectively) (P < .001). The mean AM femoral tunnel length of group II (34.3 ± 3.9 mm) was significantly longer than that of group I (31.9 ± 2.7 mm) (P = .02). However, the mean PL femoral tunnel lengths did not differ between groups. In 7 cases-4 cases (19.0%) in group I and 3 cases (16.6%) in group II-the femoral tunnel communication was found around the intra-articular aperture. Posterior wall breakage was observed in 5 cases (23.8%), which were all in AM femoral tunnels of group I.

CONCLUSIONS

The OI technique resulted in more acute femoral graft bending angles (difference of 10.9° and 12.5° for AM and PL, respectively) and longer mean AM femoral tunnel lengths (difference of 2.4 mm) than the TP technique after anatomic DB ACL reconstruction, even though these small differences might be unlikely to be of clinical significance. Femoral tunnel communication was found in both groups, and posterior wall breakage was observed in AM femoral tunnels with the TP technique.

LEVEL OF EVIDENCE

Level I, prospective randomized trial.

Comparison of femoral graft bending angle and tunnel length between transtibial technique and transportal technique in anterior cruciate ligament reconstruction

PURPOSE

To investigate which technique would reduce bending stress at the femoral tunnel aperture and make short tunnel length after ACL reconstruction by comparing the femoral graft bending angle and tunnel length between the single-bundle (SB) transtibial (TT) and double-bundle (DB) transportal (TP) technique using three-dimensional-computed tomography using OsiriX(®) imaging software.

METHODS

Forty-nine patients underwent an ACL reconstruction using a SB TT (Group I, 20 patients) and DB TP (Group II, 29 patients) technique. Femoral graft bending angle and femoral tunnel length were measured by CT image using OsiriX(®) imaging software. Groups I and II were compared, and statistical analysis was performed using SPSS software.

RESULTS

The mean anteromedial (AM) and posterolateral (PL) femoral graft bending angle of group II (111.5 ± 8.8° and 118.9 ± 9.8°, respectively) was significantly more acute than that of group I (125.3 ± 11.1°) (P < 0.001, P = 0.04). The mean femoral tunnel length of group I was significantly longer than that of group II (P = 0.001).

CONCLUSIONS

The femoral graft bending angle and the femoral tunnel length of the TP technique performed in the maximally flexed knee position was more acute and shorter than those of the TT technique after ACL reconstruction. This might increase the bending stress at the femoral tunnel aperture and shorter graft length in the tunnel after an ACL reconstruction using TP technique compared to the TT technique.

LEVEL OF EVIDENCE

III.

Impact of tibial and femoral tunnel position on clinical results after anterior cruciate ligament reconstruction

PURPOSE

The purpose of this study was to correlate anatomic and nonanatomic tibial and femoral tunnel positions after anterior cruciate ligament (ACL) reconstruction with clinical outcome by use of bone-patellar tendon-bone (BPTB) single-bundle (SB) and semitendinosus-gracilis (STG) double-bundle (DB) techniques.

METHODS

The 3-dimensional computed tomography scans of 53 patients' knees (27 BPTB-SB and 26 STG-DB) were prepared and measured by 2 examiners according to their tibial and femoral tunnel positions. We evaluated these radiologic constructions and measurements by use of the Cohen κ interobserver and intraobserver coefficient for 2 observers. Patients undergoing both techniques were divided into anatomic and nonanatomic reconstructions according to the findings of Zantop and Petersen. We correlated anatomically and nonanatomically reconstructed patients with clinical outcome by the Tegner score, Western Ontario and McMaster Universities Osteoarthritis Index score, International Knee Documentation Committee score, KT-1000 arthrometer (MEDmetric, San Diego, CA), and pivot-shift test in both techniques.

RESULTS

The radiologic constructions and measurements of 53 computed tomography scans were achieved with a good agreement of interobserver and intraobserver coefficients for 2 observers. We found significantly superior clinical outcome in anatomic ACL reconstructions in both techniques in terms of higher clinical scores (Tegner and International Knee Documentation Committee), higher anterior posterior stability, and less pivot shift. We observed the best outcome in anatomic STG-DB reconstructions.

CONCLUSIONS

This investigation showed that better clinical results are associated with anatomic ACL reconstructions.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Validation of the position of the femoral tunnels in anatomic double-bundle ACL reconstruction with 3-D CT scan

This study compares the positioning of femoral AM and PL tunnels obtained with specific ancillary instruments during anatomic double-bundle ACL reconstruction with the native ACL footprint using three-dimensional computed tomography (3-D CT). In 35 consecutive patients, anatomic double-bundle ACL reconstruction was performed with specific ancillary instruments. Three-dimensional CT reconstruction of both knees was performed using the volume rendering technique. In the controls (contralateral knee, with intact ACL), the angle between the longitudinal axis of the footprint and the axis of the femur, the "footprint angle" (FA) was measured. On the involved side, using the axis passing through the tunnel centers, FA was also measured. In both the groups, footprint's length and width, and distances to cartilage margins were measured. FA was 28.1 degrees +/- 5.0 degrees in the controls and 32.9 degrees +/- 15.8 degrees on the involved side (n.s.). There was no statistical difference between the two groups for the other morphometric parameters: footprint's length and width, and distances to cartilage margins. Using specific ancillary instruments the morphometric parameters of the reconstructed femoral ACL footprint were similar to the native ACL.

Anterior cruciate ligament insertions on the tibia and femur and their relationships to critical bony landmarks using high-resolution volume-rendering computed tomography

BACKGROUND

Controversy exists regarding the locations of the anterior cruciate ligament insertions on the femur and tibia and visualization of these insertions during surgical reconstruction.

HYPOTHESIS

Anatomical insertions of the anterior cruciate ligament have relationships to bony landmarks of the tibia and femur.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Eight cadaveric knees were scanned by computed tomography, reconstructed 3-dimensionally, and examined from simulated arthroscopic, sagittal, and axial perspectives. Volume-rendering software was used to document the relationship of the anterior cruciate ligament to the bony anatomy.

RESULTS

A bony ridge (Resident's Ridge) at the anterior border of the anterior cruciate ligament was readily noted on the medial wall of the lateral femoral condyle. Superiorly, anterior cruciate ligament fibers inserted up to the roof of the notch and to 3 to 3.5 mm of the articular surface posteriorly and inferiorly. The anterior cruciate ligament inserted into a fovea anterior to the tibial eminence. Posteriorly, anterior cruciate ligament fibers inserted up to a ridge between the medial and lateral intercondylar tubercles. Medially, anterior cruciate ligament fibers inserted onto the ridge at the lateral border of the medial tibial condyle. There was no distinct anterior or lateral bony border with anterior cruciate ligament fibers blending into the anterior horn of the lateral meniscus.

CONCLUSION

The anterior border of the femoral anterior cruciate ligament origin is Resident's Ridge. The ridge between the medial and lateral intercondylar tubercles at the base of the tibial eminence is the posterior margin of the anterior cruciate ligament on the tibia.

CLINICAL RELEVANCE

Bony landmarks can be used to aid in anatomical anterior cruciate ligament reconstruction.

Influence of knee flexion angle on femoral tunnel characteristics when drilled through the anteromedial portal during anterior cruciate ligament reconstruction

PURPOSE

The purpose of this study was to determine the influence of knee flexion angle for drilling the femoral tunnel during anterior cruciate ligament (ACL) reconstruction via the anteromedial (AM) portal on resulting tunnel orientation and length.

METHODS

In 8 fresh cadaveric knees, the ACL was excised and 2.4-mm guidewires were drilled through the AM bundle footprint using a 5-mm endofemoral aimer via the AM portal. We compared knee flexion angles of 90 degrees , 110 degrees , 130 degrees , and maximum flexion. Anteroposterior-, lateral-, and tunnel-view radiographs were measured to determine tunnel orientation, o'clock position, and direct measurement to determine intra-osseous tunnel length.

RESULTS

With regard to tunnel orientation, each increase in knee flexion angle resulted in significantly more horizontal tunnel both on the anteroposterior view and on the lateral view. While on the tunnel view, the pin became more vertical with knee flexion. At 90 degrees , tunnel length was significantly less (27 +/- 9 mm) than at greater angles, and the guidewires were either resting against the posterior cortex or breaching it.

CONCLUSIONS

The results of this study show the knee flexion angle influences the position of the femoral drilling. It appears in the current study that 110 degrees is optimum, while the 90 degrees pin leads to short tunnel and is so close to the posterior wall there are high risks of posterior wall blow out when drilling the tunnel at its final diameter. Also, 130 degrees of knee flexion is responsible for high tunnel acuity and, finally, maximum flexion being quite variable from one specimen to another cannot be recommended.

CLINICAL RELEVANCE

Tunnels drilled through the AM portal at 90 degrees are at risk of back wall blow out.