2015 ISAKOS Biennial Congress ePoster #1280

Clinicoradiographic Evaluation of Anatomic Double Bundle ACL Reconstructions Using Footprint Visualization and Anatomic Aimer Techniques

Vinod Kumar, MBBS, MS, DNB, MNAMS, New Delhi, Delhi INDIA
Dhananjaya Sabat, MS, DNB, MNAMS, New Delhi, New Delhi INDIA

Maulana Azad Medical College New Delhi, New Delhi, New Delhi, INDIA

FDA Status Not Applicable

Summary: CT evaluation of tunnel positions revealed that PL tunnel position was not always anatomic by either foot print visualisation or Anatomic aimer technique, though the clinical outcomes are comparable in short term.

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Abstract:

Background

The purpose of this study is to compare the clinical results and various properties (e.g. tunnels position and diameter) of anatomically placed anteromedial (AM) and posterolateral (PL) tunnels on the femur and tibia with help of radiographs and CT-scan in double-bundle anterior cruciate ligament (ACL) reconstruction with two different techniques i.e. arthroscopic footprint visualization technique or with the use of a dedicated aimers for femoral and tibial tunnel preparation.

Methods

20 patients in each group were included in the study. Clinical comparison at 1 year was done using anterior drawer test, Lachman test, pivot shift test, arthrometric evaluation, Lysholm’s score and IKDC 2000 grading. X-ray and CT scans were performed on each operated knee and as well as corresponding normal knee. CT scan volume rendered technique (VRT) was used to create 3-D models and “anatomic co-ordinate axes system” was used for measurements of tunnel positions.

Results

At one year follow up; 6 patients (30%) of anatomic aimer group and 4 (20%) of footprint technique group had grade 1 anterior laxity where as 2 patients in each group (10%) had grade 1 pivot positive. IKDC and Lysholm’s scores improved significantly in both groups but on inter group comparison, both groups were comparable. Manual laxity testing with KT 2000 arthrometer showed mean side to side difference of 1.3±0.0881 mm and 1.4±0.843 mm in the respective groups.
On CT scan 3D models, on the medial wall of the lateral femoral condyle in the anatomic posterior to anterior direction (PAF), the AM femoral tunnel centers were located at a mean of 46.8±0.074% in aimer group and 56.4±3.11% in the footprint group, and the PL tunnel centers were at 34.5±5.0% and 40.5±9% respectively. The proximal to distal location (PDF) for the AM tunnel centres were at a mean 24.1±7.1% in aimer group and 25.9±6.7% in the footprint group, and the PL tunnel centres were 61.6±4.8% and 64.8±6.4% respectively.
On the tibial side, the anterior to posterior tibial plateau depth (APT) and the medial to lateral tibial plateau width (MLT) were measured. The APT for centers of the AM and PL tunnels were located at a mean of 29.7±2.5% and 46.7±3.8% in aimer group and 28.8±4.3% and 46.2 ±3.6% in footprint group respectively. Similarly, the MLT for centers of the AM and PL tunnels were located at a mean of 45.2±2.5% and 52.4±3.1% in aimer group and 46.5±2.9 and 50.6±2.8 in footprint group.
On the normal side, the approximated centre of anatomic footprint AM and PL bundle on femur were measured. For the AM and PL centers, PAF was 26.9±4.2% and 16.9±3.6%, and PDF was 22.5±2% and 49.8±6.2%.

Conclusion

The clinical outcome in short term is comparable for double bundle ACL reconstructions using both footprint method and anatomic aimers. CT evaluation of tunnel positions revealed near anatomic positioning of AM tunnels on femur and both AM and PL tunnels on tibia, where as the PL tunnel is positioned more distal and anterior in both methods used. There is further scope of improvement in both the techniques to recreate the natural footprints of both AM & Pl bundles.
Level of study: Theraputic Level II