Minimizing Unnecessary Harvesting of an Extremely Thin Gracilis Tendon During ACL Reconstruction by Referencing the Diameter of the Doubled Semitendinosus Tendon Alone.

BACKGROUND

The incidence of anterior cruciate ligament reconstruction (ACLR) graft failure is inversely related to the diameter of the ACLR graft. When the diameter of a 4-stranded hamstring tendon graft with a doubled semitendinosus and doubled gracilis tendon (ST×2 + G×2) configuration is <8 mm, the gracilis tendon is often thin.

HYPOTHESIS

(1) The diameter of the doubled semitendinosus tendon (ST×2) alone would be able to predict the probability of a 4-stranded ACLR graft having a diameter of ≥8 mm, and (2) there would be a specific cutoff value for the ST×2 diameter such that the addition of a doubled gracilis tendon (G×2) will not result in a 4-stranded graft with a ≥8-mm diameter.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Included were patients who had undergone 4-stranded hamstring ACLR between 2008 and 2018. Patients were excluded if the diameter measurements of the tendons or ACLR graft were missing. A receiver operating characteristic (ROC) analysis was performed to assess the predictability of ST×2 on an ACLR graft with a diameter of ≥8 mm. The effect of including G×2 on the final graft size was reported.

RESULTS

A total of 314 patients were included, and the mean diameters of ST×2 and G×2 were 6.5 ± 0.8 mm and 5.0 ± 0.7 mm, respectively. There was a moderate to strong correlation between the diameter of ST×2 and that of G×2 (men: = 0.678; women: = 0.654; < .001 for both). An ST×2 with a diameter <6 mm predicted a 4-stranded ACLR graft of <8 mm (area under the ROC = 0.917; < .001). When ST×2 was <6 mm, the addition of a G×2 did not result in the ACLR graft's having a diameter of ≥8 mm, regardless of patient sex or G×2 diameter.

CONCLUSION

When the diameter of the doubled semitendinosus was <6 mm, the addition of the doubled gracilis was unlikely to produce a 4-stranded ACLR graft with a diameter of ≥8 mm. Surgeons should consider alternative methods such as tripling or quadrupling the semitendinosus tendon to increase the size of the ACLR graft, rather than routinely harvesting the gracilis tendon.