A comparative study of anatomical single-bundle anterior cruciate ligament reconstruction using femoral offset aimer versus freehand technique for femoral tunnel preparation

Freehand vs. Medial Portal Offset Aimer Technique for Accurate Femoral Tunnel Placement in Arthroscopic ACL Reconstruction

Purpose

In this study, our aim was to reveal the effect of the medial femoral offset aimer usage through the femoral tunnel entry and exit points and the tunnel length during femoral tunnel drilling in arthroscopic anterior cruciate ligament (ACL) reconstruction.

Methods

One hundred patients who underwent arthroscopic single-bundle ACL reconstruction were included in the study. Group 1 consisted of 50 patients who underwent femoral tunnel drilling using a medial portal offset aimer device, while Group 2 consisted of 50 patients who were operated on using the freehand technique. Both groups were compared in terms of femoral tunnel and graft tunnel lengths, femoral tunnel angle in the coronal plane, and the location of the femoral tunnel entry and exit points.

Results

The mean femoral tunnel and graft tunnel lengths were significantly longer in Group 2 (p = 0.000). There was no significant difference in terms of localization of the femoral tunnel entry point in both the axial and sagittal planes. The tunnel exit point was located significantly more posterior in Group 1 in the axial plane (p = 0.028). There was no significant difference in terms of the coronal plane femoral tunnel angle between the two groups.

Conclusion

In arthroscopic ACL reconstructions, more successful results may be obtained with the freehand technique compared to drilling with a femoral offset aimer. For an experienced orthopedic surgeon, using a medial portal offset aimer device during femoral tunnel drilling does not seem necessary.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-023-00929-z.

Does radiological evaluation of endobutton positioning in the sagittal plane affect clinical functional results in single-bundle anterior cruciate ligament reconstruction?

INTRODUCTION

Sports injuries are increasing today due to the increased interest in sports. The most common injured knee ligament is the anterior cruciate ligament (ACL) in sport injuries. Accordingly, surgical treatment of the ACL is performed frequently. In this study, it was aimed to retrospectively evaluate whether the location of an endobutton on lateral knee radiography was effective on knee functional scores in patients who underwent ACL reconstruction.

MATERIALS AND METHODS

One hundred thirty patients who underwent ACL reconstruction between January 2015 and February 2019 were identified. The patients were divided into three groups according to the location of the endobutton on lateral radiographs taken in the postoperative period. Group 1 patients were classified as anterior, group 2 as middle, and group 3 as posterior according to the location of the endobutton. Functional scoring, physical examination tests, comparative thigh diameter measurements, and single-leg hop tests were compared between the groups. It was evaluated as to whether there was a statistically significant difference between the groups.

RESULTS

There were 38 patients in group 1, 63 patients in group 2, and 29 patients in group 3. The mean age was 29.1 in group 1, 29.1 in group 2, and 29.7 in group 3. The mean follow-up period of the patients was 18.4 months in group 1, 19.1 months in group 2, and 21.4 months in group 3. The average Lysholm score was 92.9 in group 1, 93.3 in group 2, and 91.7 in group 3. The mean modified Cincinnati scores were 27.0, 27.1, and 26.6, respectively, in the groups. The mean IKDC score of the subjective knee assessments was 92.5, 92.8, and 91, respectively, according to the groups. The average thigh atrophy value was 1 cm, 1 cm, and 1.2 cm, respectively, in the groups. In the single-leg hop test, 34 patients in group 1 jump to over 85% of the distance compared with the intact side, while 58 patients in group 2, and 23 patients in group 3 were successfully able to jump this distance. The effect of the placement of the endobutton in the anterior, middle or posterior was not statistically significant on functional scores and physical examination results. In patients with endobuttons in the middle, functional scores were found better than in those with anterior or posterior placement.

CONCLUSIONS

No statistically significant differences were found in clinical functional results when comparing patients' endobutton location on femur. For this reason, surgical time should not be extended using unnecessary extra effort to change the orientation of the exit hole during surgery.

3D CT evaluation of femoral and tibial tunnels in anatomic double bundle anterior cruciate ligament reconstruction

BACKGROUND

An anatomical double bundle ACL reconstruction replicates the anatomy of native ACL as the tunnels are made to simulate the anatomy of ACL with AM and PL bundle foot prints. The goal of anatomic ACL reconstruction is to tailor the procedure to each patient's anatomic, biomechanical and functional demands to provide the best possible outcome. The shift from single bundle to double bundle technique and also from transtibial to transportal method has been to provide near anatomic tunnel positions.

PURPOSE

To determine the position of femoral and tibial tunnels prepared by double bundle ACL reconstruction using three dimensional Computed tomography.

STUDY DESIGN

A prospective case series involving forty patients with ACL tear who underwent transportal double bundle ACL reconstruction.

METHOD

Computed tomography scans were performed on forty knees that had undergone double bundle anterior cruciate ligament reconstruction. Three-dimensional computed tomography reconstruction models of the knee joint were prepared and aligned into an anatomical coordinate axis system for femur and tibia respectively. Tibial tunnel centres were measured in the anterior-to-posterior and medial-to-lateral directions on the top view of tibial plateau and femoral tunnel centres were measured in posterior to anterior and proximal-to-distal directions with anatomic coordinate axis method. These measurements were compared with published reference data.

RESULTS

Analysing the Femoral tunnel, the mean posterior-to-anterior distances for anteromedial and posterolateral tunnel centre position were 46.8% ± 7.4% and 34.5% ± 5.0% of the posterior-to-anterior height of the medial wall and the mean proximal-to-distal distances for the anteromedial and posterolateral tunnel centre position were 24.1% ± 7.1% and 61.6% ± 4.8%. On the tibial side, the mean anterior-to-posterior distances for the anteromedial and posterolateral tunnel centre position were 28.8% ± 4.3% and 46.2% ± 3.6% of the anterior-to posterior depth of the tibia measured from the anterior border and the mean medial-to-lateral distances for the anteromedial and posterolateral tunnel centre position were 46.5% ± 2.9% and 50.6% ± 2.8% of the medial-to-lateral width of the tibia measured from the medial border. There is high Inter-observer and Intra-observer reliability (Intra-class correlation coefficient).

DISCUSSION AND CONCLUSION

Femoral AM tunnel was positioned significantly anterior and nearly proximal whereas the femoral PL tunnel was positioned significantly anterior and nearly distal with respect to the anatomic site. Location of tibial AM tunnel was nearly posterior and nearly medial whereas the location of tibial PL tunnel was very similar to the anatomic site Evaluation of location of tunnels through the anatomic co-ordinate axes method on 3D CT models is a reliable and reproducible method. This method would help the surgeons to aim for anatomic placement of the tunnels. It also shows that there is scope for improvement of femoral tunnel in double bundle ACL reconstruction through transportal technique.