Summary

Patients with a graft diameter of 4.5 mm were placed group (n=37), while those with a graft diameter of >=5 mm were placed group (n=44) underwent anatomic double-bundle ACL reconstruction using semitendinosus tendon autografts. No differences were found for instability,muscles strength, the IKDC/Lysholm score, return to sports and graft failure rate.

Abstract

Purpose

Anatomical double-bundle anterior cruciate ligament reconstruction (ACLR) using semitendinosus tendon has spread widely as a treatment for the ACL tear. In a recent study, several authors have suggested small diameter hamstring tendon may influence not only the risk of revision but also patient-reported outcomes. Especially in short stature, a graft diameter of less than 5 mm is frequently encountered. However, there is no study clarifying the relevance between small-diameter grafts and clinical outcome. The aim of this study was to compare the relationship between graft size and clinical outcome after double-bundle ACLR.

Materials And Methods

Eighty-one patients (mean age 19.6 years old) underwent anatomical double-bundle ACLR using semitendinosus tendon autografts for ACL deficiency. The patients were divided into two groups according to each prepared graft diameter. Patients with grafts diameter in 4.5 mm were placed in the small-diameter group (n = 37), while those with grafts diameter in 5 mm or more were placed in the standard-diameter group (diameter range 5 – 6.5 mm, n = 44). The comparative parameters were instrument-measured anterior laxity (KS measure), pivot-shift test, Peak isokinetic (60°/s) and isometric (80° of flexion) torque of the quadriceps and the hamstrings, one-leg hop test, International Knee Documentation Committee (IKDC) subjective score, Lysholm score, Tegner activity scale, and graft failure rates. Each patient underwent clinical examination one year after surgery. Statistical analysis between two groups was performed using Student’s t-test and chi-square test.

Results

All preoperative characteristics except height showed no statistical differences. In the mean height, there was a significant difference (P = .039). At one-year follow-up, the mean side-to-side difference for KS measure showed no significant difference between two groups (P = .611). In pivot-shift test, two patients (6.1%) were evaluated as glide in the small-diameter group, while all patients were normal in the standard-diameter group (P = .121). Regarding other clinical results, the mean peak isokinetic (quadriceps: P = .754, hamstrings : P = .643) / isometric (quadriceps : P = .541, hamstrings : P = .636) torque and one-leg hop test (P = .855) showed no significant differences. Additionally, there were no significant differences in the mean IKDC subjective score (P = .600), the mean Lysholm score (P = .820) and the mean Tegner activity scale (P = .613). All patients returned to their previous sports activity level and returned to sports at an average of 8.3 months in the small-diameter group and 8.6 months in the standard-diameter group (P = .222). Graft failure rates were two patients (5.4%) in the small-diameter group and three patients (6.8%) in the standard-diameter group (P = .792).

Conclusion

Our study clarified that ACLR using small-diameter grafts showed excellent clinical results and the rate of return to previous sports activity one year after surgery. For short patients who may have narrow femoral intercondylar notch, small-diameter grafts are considered an adequate graft size and are available to achieve proper fixation due to determine more optically femoral tunnel position on the original footprint area.