Influence of change of tunnel axis angle on tunnel length during double-bundle ACL reconstruction via the transportal technique

An Analysis of the Femoral Drilling Angle to Avoid Tunnel Collision during Double-Bundle Anterior Cruciate Ligament and Anterolateral Ligament Reconstruction on the Knee

Concomitant anterior cruciate ligament (ACL) and anterolateral ligament (ALL) reconstruction has been reported as an effective technique for providing rotational control of the knee. However, the intraoperative risk of collision with an ACL tunnel during the drilling for the femoral ALL tunnel has been described. The purpose of this study was to investigate the various femoral drilling procedures to avoid tunnel collisions during combined double-bundle ACL and ALL reconstruction. Nine cadaveric knees were used in this study. ACL drilling was performed through the anteromedial portal to footprints of the posterolateral bundle at 120° (PL120) and 135° (PL135) knee flexion and the anteromedial bundle at 120° (AM120) and 135° (AM135) knee flexion. ALL drilling was performed at 0° (Cor0-ALL) and 30° (Cor30-ALL) coronal angles using a Kirschner wire (K-wire). The distance between the ALL footprint and ACL K-wire outlets, axial angles of ALL K-wires colliding with ACL K-wires, and distances from the ALL footprint to the collision point were measured. From these values, the safe zone, defined as the range of axial angles in which no collisions or penetrations occurred, was identified by simulation of tunnels utilized for reconstruction grafts in each drilling procedure. The point-to-point distance from the ALL footprint to the K-wire outlet was significantly greater in the AM120 than the AM135 (13.5 ± 3.1, 10.8 ± 3.2 mm; p = 0.048) and in the PL135 than the PL120 (18.3 ± 5.5, 16.1 ± 6.5 mm; p = 0.005) conditions, respectively. During an ACL drilling combination of PL135/AM120, a safe zone of > 45° in Cor30-ALL was identified. With a narrow safe zone during the PL135/AM120 combination only, the risk of femoral tunnel collisions in combined double-bundle ACL and ALL reconstruction is high. AM drilling at 120° and PL drilling at > 135° knee flexion, combined with ALL drilling at 30° coronal angle and > 45° axial angle, may reduce this risk.

A comparative analysis of the efficacy of anterior cruciate ligament reconstruction with autologous ligament grafting at different time points

BACKGROUND

This study was performed to compare the clinical efficacies of anterior cruciate ligament (ACL) reconstruction with autologous ligament grafting at different time points.

METHODS

Eighty-five patients with ACL were categorized into two groups: Group A (GA, n = 45), who underwent early-stage (≤3 weeks) surgery, and Group B (GB, n = 40), who underwent advanced-stage (>3 weeks) surgery. Perioperative conditions, knee joint functions, activity and stability before and at 6 months postoperatively, changes in quality of life (QOL), good and excellent rates of knee joint functions, and incidence of complications were compared between the two groups.

RESULTS

In both groups, there was an increase in the International Knee Documentation Committee (IKDC) score, Lysholm score, and QOL and a decrease in the knee joint angle flexion limitation, angle of spread limitation, positive rates in the anterior drawer test (ADT), and Lachman test score (P < .05) after surgery. At 6 months postoperatively, the IKDC score, Lysholm score, and QOL were higher in GA than in GB (P < .05). The good and excellent rates of knee joint functions were higher in GA than in GB (93.33% vs. 77.50%) (P < .05).

CONCLUSION

Anterior cruciate ligament reconstruction with autologous ligament grafting can achieve good effects whether performed in the early or advanced stage; however, the improvements in patients' knee joint functions and QOL are better in the early stage. Therefore, early ACL reconstruction with autologous ligament grafting is suggested.

Flexible reamers create comparable anterior cruciate ligament reconstruction femoral tunnels without the hyperflexion required with rigid reamers: 3D-CT analysis of tunnel morphology in a randomised clinical trial

PURPOSE

The hyperflexion required for femoral tunnel drilling in anterior cruciate ligament reconstruction can be challenging in patients with increased body habitus or musculature. Whilst allowing femoral tunnel creation without hyperflexion, additional benefits of flexible reamers have been proposed in terms of tunnel dimensions. The purpose of this study was to examine whether these theoretical benefits are seen in a clinical study.

METHODS

Fifty adult patients (with isolated anterior cruciate ligament rupture) were randomised to reconstruction with either flexible or rigid femoral reamers. Femoral tunnel drilling was performed at 100° flexion (flexible system) or maximal hyperflexion (rigid system). Otherwise, the procedure was standardised. Femoral tunnel measurements were performed by a consultant musculoskeletal radiologist who was blinded to the method of femoral drilling. Tunnel position, length and angles (axial and coronal) were measured alongside aperture shape and exit point using three-dimensional computed tomography 3-6 months post-operatively.

RESULTS

With no difference in tunnel position, tunnel length was found to increase with the use of the flexible system (37.8 ± 3.7 vs 35.0 ± 4.4 mm; p = 0.024). In addition, the exit point and fixation device were more anterior on the lateral femur using the flexible reamers (p = 0.016). No difference was seen in either tunnel angles or aperture shape. One case of incomplete posterior blow-out was seen in each of the study groups.

CONCLUSIONS

This comparative study shows that flexible reamers can reproduce a desired femoral tunnel position with only small improvements of no clinical relevance. As this can be achieved without hyperflexing the knee, these systems can be used for all patients (even when hyperflexion is a challenge).

LEVEL OF EVIDENCE

I.

Anteversion and length of the femoral tunnel in ACL reconstruction: in-vivo comparison between rigid and flexible instrumentation

Background

Due to it being tangential to the distal femoral axis, the anteromedial portal presents significant risk of causing iatrogenic damage, and of producing tunnels that are too short for optimal osseointegration. Flexible reamers were developed to eliminate the need for knee hyperflexion and offer better-controlled orientation of the femoral tunnel. We aimed to compare the anteversion and length of femoral tunnels drilled using flexible reamers to those drilled using rigid reamers.

Methods

Between May 2012 and December 2013, all patients receiving ACL reconstruction performed by one surgeon were operated on using either a rigid or a flexible reamer from the same supplier (Versi-Tomic® system, Stryker, Kalamazoo, Michigan). The height of each patient was recorded, and the length and anteversion of the femoral tunnels were measured intra-operatively and on true lateral radiographs, respectively.

Results

Thirty-seven patients underwent operations using the rigid instrumentation, and 43 using the flexible instrumentation. There was no statistically significant difference between the two groups in either sex or height (p = n.s.). The patients operated on using the rigid instrumentation had tunnels anteverted by 18.6° ± 6° and 33.6 ± 2.9 mm long. Those operated on using the flexible instrumentation had tunnels anteverted by 40° ± 2° and 41.1 ± 3.57 mm long. Both anteversion and tunnel length were significantly greater for tunnels drilled using the flexible instrumentation (p < 0.001).

Conclusions

This study demonstrated that flexible reamers produce significantly more anteverted and longer femoral tunnels during ACL reconstruction than rigid reamers. Clinical studies remain necessary to assess the outcomes of ACL reconstruction using flexible reamers.