Reliability of tunnel angle in ACL reconstruction: two-dimensional versus three-dimensional guide technique

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Sports Medicine

Background:

• Anterior Cruciate Ligament (ACL) reconstruction is a common orthopedic procedure.
• Accurate tibial tunnel placement is crucial for successful ACL graft fixation and long-term outcomes.
• Existing standard ACL guides may have limitations in achieving precise tunnel positioning.

Purpose of the Study:

• To compare the reliability of tibial tunnel position and angle using a standard two-dimensional (2D) ACL guide versus a three-dimensional (3D) Howell 65° Guide.
• To evaluate tunnel placement in both coronal and sagittal planes.

Main Methods:

• A case-control retrospective comparative study (Level III) was conducted.
• Radiographic analysis of anteroposterior and lateral views was performed on 28 (2D guide) and 24 (3D Howell guide) patients.
• Tibial tunnel position and angle were measured by multiple investigators at least three times.

Main Results:

• The 3D Howell guide achieved a more consistently horizontal tibial tunnel angle in the coronal plane (64.7° ± 6.2°) compared to the 2D guide (61.3° ± 4.8°).
• Tibial tunnel position in the sagittal plane was more anterior with the 2D guide (41.6% ± 2.5%) than with the 3D Howell guide (43.3% ± 2.9%).

Conclusions:

• The Howell 65° Guide demonstrates reliable tibial tunnel placement in the coronal plane.
• Both techniques resulted in tibial tunnels situated within the native ACL's anatomical footprint.
• Further research is recommended to explore the clinical impact of tibial tunnel angle on knee function and patient quality of life.