Alternate Method of Arthroscopically Confirming Femoral Button Deployment for Knee Anterior Cruciate Ligament Graft Suspensory Cortical Fixation

Arthroscopic Confirmation of Femoral Button Deployment During Posterior Cruciate Ligament Reconstruction

Posterior cruciate ligament (PCL) ruptures are uncommonly seen in knee ligament injuries. Cconservative treatment is often suitable for isolated tears with mild-to-moderate posterior knee laxity (grades I or II). However, surgical intervention is indicated for symptomatic grade III or multiligament knee injuries. PCL reconstruction has experienced continuous development due to the progress made in arthroscopic techniques and instruments. Abnormal positioning and tensioning of the femoral button result in multiple complications such as residual laxity, loss of quadriceps muscle strength, and joint stiffness. In this Technical Note, we describe direct arthroscopic visualization of the femoral button deployment in PCL reconstruction technique, and we discuss its importance to prevent complications related to button malposition.

Anterior Cruciate Ligament Reconstruction Using Femoral Cortical Button Fixation: A Case Series of Intraoperative Malpositioning

Background

Malpositioning of the femoral button is a known technical complication after anterior cruciate ligament (ACL) reconstruction with cortical suspensory fixation. The incidence of malpositioning, as well as the efficacy of methods to prevent malpositioning of cortical suspensory fixation devices, has not been reported.

Purpose

To determine the rate of malpositioned cortical suspensory fixation devices after ACL reconstruction, investigate which intraoperative technique yields the lowest rate of malpositioning, and determine the return-to-duty rate for active-duty service members with malpositioned buttons and the revision rate for malpositioned buttons.

Study Design

Case series; Level of evidence, 4.

Methods

The records of patients who underwent primary ACL reconstruction with a cortical suspensory fixation device between 2008 and 2018 were reviewed at our institution. Postoperative radiographs were reviewed for evidence of malpositioned femoral buttons. Malpositioned buttons were classified as (1) fully positioned in the bone tunnel, (2) partially positioned in the bone tunnel, (3) >2 mm from cortical bone, or (4) deployed over the iliotibial band. Operative reports were reviewed to determine the intraoperative methods undertaken to verify the button position. The rate of malpositioned cases with subjective instability and revision surgery performed were determined. The ability of patients to return to full military duty was reviewed for active-duty personnel.

Results

A total of 1214 patients met the inclusion criteria. A 3.5% rate (42 cases) of malpositioned cortical suspensory fixation devices (femoral buttons) was identified. For patients with malpositioned buttons, 7 (16.7%) patients underwent revision surgery in the immediate postoperative period. Techniques used to avoid malpositioning included direct arthroscopic visualization, direct open visualization, intraoperative fluoroscopy, and first passing the button through the skin before positioning on the femoral cortex. There was a 4.6% malposition rate using direct arthroscopic visualization and a 5.1% malposition rate using passage of the button through the skin, while no malpositioning occurred with intraoperative fluoroscopy or direct open visualization (P < .05). Overall, 12 (28.6%) patients with malpositioned buttons ultimately underwent revision surgery. Despite having been diagnosed with malpositioned buttons, 21 (63.6%) active-duty members were able to return to full duty.

Conclusion

Malpositioning of femoral buttons during ACL reconstruction occurred in 3.5% of patients in this series. The techniques of intraoperative fluoroscopy and direct open visualization are encouraged to prevent malpositioning.

Risk Factors for Femoral Cortical Button Malposition in Posterior Cruciate Ligament Reconstruction

Background

Femoral cortical button suspension fixation is a popular and reliable technique for posterior cruciate ligament reconstruction (PCLR). Button malposition during graft fixation can lead to postoperative graft loosening.

Purpose

To determine the risk factors of femoral cortical button malposition in PCLR when neither direct visualization nor intraoperative fluoroscopy is used.

Study Design

Case-control study; Level of evidence, 3.

Methods

Of the 206 consecutive patients who underwent PCLR without direct visualization or intraoperative radiographs in 2019 at a single institution, 182 met the selection criteria and were included in the study. The distance from the suspension button to the femoral cortex was measured on postoperative computed tomography scans. The button was considered malpositioned if its distance to the femoral cortex was ≥2 mm. We evaluated patient-related and surgery-related variables, including age, sex, concomitant ligament reconstruction, button type, and surgeon experience. Multivariate logistic regression was conducted to evaluate the risk factors for button malposition.

Results

The overall prevalence of button malposition was approximately 17.0% (31/182), and the mean distance from the button to the femoral cortex was 6.11 ± 5.82 mm in the malposition group. Male sex was the most significant risk factor for button malposition (odds ratio [OR], 13.86; 95% confidence interval [CI], 1.73-111.17; P = .013). Other independent risk factors were low surgical volume (completing ≤3 procedures; OR, 6.41; 95% CI, 1.89-21.72; P = .003), concomitant ligament reconstruction (OR, 5.56; 95% CI, 2.12-14.58; P < .001), and fixed-loop button (OR, 3.96; 95% CI, 1.11-14.18; P = .034).

Conclusion

Male sex, low surgical volume, concomitant ligament reconstruction, and fixed-loop button were independent risk factors for femoral cortical button malposition during PCLR.

Arthroscopic confirmation of femoral button deployment avoids post-operative X-ray in ACL reconstruction

BACKGROUND

Anterior cruciate ligament reconstruction (ACLR) with cortical fixation adjustable-loop devices are associated with high potential risk of button malpositioning or interposition of the soft tissue between lateral femoral cortex and the button. Surgeons usually use X-rays to check and avoid button malposition and soft tissue interposition. Arthroscopic visualization of button position through the lateral gutter has been described. With this technique, it is possible for identification and correction of femoral button malalignment in the setting of soft tissue interposition and it could avoid the use of post-operative X-ray.

METHODS

A total of 193 ACLR were included and patients were randomized into two groups. The first series (Group A) of 112 patients who sustained an ACLR with post-operative X-ray to assess the position of the femoral button and the second series (Group B) of 81 patients who sustained an ACLR with an arthroscopic exploration of the button followed by post-operative X-ray.

RESULTS

On the post-operative radiographs, tissue interposition between the button and femoral cortex was found in nine cases of 112 in Group A (8%) and in zero case of 81 in Group B (0%). In six cases (7,4%) in Group B, there was a soft tissue interposition between the button and femoral cortex as visualized by arthroscopic confirmation and before post-operative X-ray; in all these cases, the soft tissue was removed, and the button was in contact with the bone in all X-ray made in the Group B.

CONCLUSIONS

This technique allows for identification and correction of femoral button malalignment in the setting of soft tissue interposition and reduces the use of post-operative X-ray.

Confirmation of Femoral Button Deployment Under Direct Visualization During ACL Reconstruction Is Not Beneficial

The purpose of this study was to determine whether direct visualization of adjustable-loop cortical suspensory button deployment onto the lateral femur increases the cortical contact rate of the button, thereby improving clinical outcomes after anterior cruciate ligament (ACL) reconstruction. Sixty-five single-bundle anteromedial portal ACL reconstructions using an adjustable-loop button were retrospectively divided into 2 groups according to use of the blind pulling technique (control group; 32 patients) or the direct visualization technique (visualization group; 33 patients) when confirming deployment of the button. Cortical contact rate of the button on immediate and 2-year postoperative radiographs, knee stability measured using a KT-1000 arthrometer, and functional scores (Lysholm score and International Knee Documentation Committee score) at 2 years postoperative were compared between the groups. There was no significant difference in femoral cortical contact rate between the groups immediately (56% control group vs 55% visualization group; P=1.000) and at 2 years postoperative (78% control group vs 82% visualization group; P=.764). At 2 years postoperative, there was no difference between the groups regarding knee stability (1.3±0.9 mm vs 1.5±0.8 mm, respectively; P=.404), Lysholm score (P=.436), and International Knee Documentation Committee score (P=.507). Confirmation of adjustable-loop button deployment under direct visualization during anteromedial portal ACL reconstruction neither increased cortical contact rate nor improved clinical outcomes. [Orthopedics. 2020;43(5);270-276.].