Predicted quadriceps vs. quadrupled hamstring tendon graft size using 3-dimensional MRI.

BACKGROUND: The objective of this study is to (1) compare the predicted cross-sectional area and diameter between quadriceps tendon and quadrupled hamstring autografts, and (2) assess the predicted size of the quadriceps tendon graft in patients with hamstrings that are insufficient for use in ACL reconstruction.

METHODS: A retrospective review of 54 knee 3D MRIs was conducted. Quadriceps tendon graft area was defined as a one-centimeter wide area of quadriceps tendon, measured three centimeters above the patella perpendicular to tendon axis. Quadrupled hamstring graft area was defined as double the combined areas of the gracilis and semitendinosus tendon, measured three centimeters above the joint line perpendicular to tendon axis. Pearson correlation was used to compare the quadriceps tendon and quadrupled hamstring grafts.

RESULTS: Mean cross-sectional area of quadrupled hamstring and quadriceps tendon grafts were 47.2 mm2 and 84.4 mm2 respectively. A statistically significant positive correlation exists between quadrupled hamstring graft and quadriceps tendon graft cross-sectional area (r = 0.41; p = 0.002). Nine of the 54 patients had predicted quadrupled hamstring grafts deemed insufficient for use in ACL reconstruction (<8 mm diameter). All of these patients had predicted quadriceps tendon graft diameters >8 mm.

CONCLUSION: There is a positive correlation between predicted quadriceps tendon and quadrupled hamstring grafts. While 17% of patients in this series had predicted insufficient quadrupled hamstring grafts, all of the patients had predicted quadriceps tendon grafts of sufficient size for ACL reconstruction. Quadriceps tendon grafts are a viable alternative in patients at-risk for insufficient quadrupled hamstring grafts.

LEVEL OF EVIDENCE: IV.