gms | German Medical Science

Objectives: We reported the clinical outcome and femoral tunnel width, anatomic or non-anatomic location of the femoral tunnel and anterior knee stability implementing the use of the direct expandable fixation of autologous Hamstring grafts. Aperfix is a relatively new system for femoral fixation. Majority of the studies were done using transtibial non-anatomic technique with direct expandable system. Also the effect of anatomic or non-anatomic position of the femoral tunnel on tunnel widening has not been investigated thoroughly. Maintaining graft stability in the bony tunnels is crucial in avoiding joint laxity. Direct fixation primarily depends on jamming of the graft on the bone. If the tunnel widens, it is logical to expect instability at the graft bone interface.

Methods: We evaluated a total of 80 (79 male, 1 female) patients that anatomic femoral tunnel placement via accessory medial portal (AMP) was done in 38 patients (Group A), non-anatomic femoral tunnel preparation was done by trans-tibial (TT) technique in 42 patients (Group B). Mean follow-up time was 40,7 months (27 - 60). All the patients were examined with KT-1000 (MEDmetric, San Diego, CA) arthrometer and assed with International Knee Documentation Committee (IKDC), Lysholm, and Tegner scores. Postoperative and final x-rays were compared for femoral tunnel widening.

Results and Conclusion: Femoral tunnel widening was significantly related to the anterior joint stability when the 80 patients were evaluated as a single group (p< 0.001). Clinical outcomes (Lysholm scores) of all of the 80 patients were also significantly related to the femoral tunnel widening (p<0.05).

There was no relation between femoral tunnel widening and anterior joint stability or clinical outcomes in Group A, but in Group B the relationship was significant in these parameters (p<0.05, p<0.01 respectively) (table 3). Femoral tunnel was significantly wider in Group B (p<0.001). Anterior knee translation was significantly higher in Group B (p=0.01). The clinical outcomes were not significantly different between the two groups (p=0.06).

Anterior knee translation and lysholm scores were inversely correlated in Group A (p<0.05), whereas there was no such correlation in Group B patients.

Femoral tunnel width was significantly greater in Group B (p<0.001), and anterior knee translation was also significantly higher in Group B (p=0.01). There was no significant difference between Lysholm and Tegner scores of the two groups (p=0.07).

In conclusion, we demonstrated that femoral tunnel widening was related to increased anterior joint laxity and worse clinical outcome in direct fixation techniques for ACL reconstruction, particularly in non-anatomic positioned femoral tunnels. Anatomic placement of the femoral tunnel in direct fixation techniques for ACL reconstruction provides better stability and less widening.