Background: Hamstring (HS) graft size is an independent risk factor in determining outcomes related to anterior cruciate ligament reconstruction (ACLR). Although anthropometric correlations with HS tendon size have been studied, a predictable association with resultant graft size has not been established. This study directly compares the difference in diameter between a 4-strand (4S) and 5-strand (5S) HS autograft in the same patient. Methods: A total of 31 consecutive patients undergoing ACLR with HS autograft were included in the study. The gracilis and semitendinosus tendons were harvested for each patient. The diameters and lengths of a standard 4S HS graft followed by that of 5S HS graft with a tripled semitendinosus tendon were measured and recorded for each patient. Results: There were a total of 17 males included in the study, with an average age of 32.7 years. The average 4S HS graft measured 7.2 mm in diameter versus the 5S graft that averaged 9.0 mm in the same patient, with an average increase of 1.8 mm (P < 0.001). The calculated cross sectional area for a 4S HS graft was 40.7 mm2 versus 63.6 mm2 for a 5S graft (P < 0.001). Conclusion: This is the first study to directly compare the difference in diameter between a 4S and 5S HS autograft in the same patient. A 5S graft reliably increases the diameter of a HS autograft in the same patient by at least 1 mm without sacrificing graft or tunnel length to a degree that may be detrimental to the overall quality of the reconstruction.
Richter, Dustin L.; Michael Hopson; Tony Pedri; and Gehron P. Treme. "Side-by-Side Comparison of 4-Strand Versus 5-Strand Hamstring Graft Diameters in Patients Undergoing Anterior Cruciate Ligament Reconstruction." Western Journal of Orthopaedics 9, 1 (2020). https://digitalrepository.unm.edu/wjo/vol9/iss1/32