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

Abstract

<p><strong>Background</strong></p><p>When the diameter of a 4-strand hamstring anterior cruciate ligament reconstruction (ACLR) graft is less than 8 mm, the gracilis tendon (G) is often thin and may not contribute significantly to an increase in the ACLR graft size. </p><p><br></p><p><strong>Hypothesis</strong></p><p>It is hypothesized that the diameter of the semitendinosus (ST) alone can predict the probability of an ACLR graft having a minimal diameter of 8 mm. It is further hypothesized that there is a specific cut-off value in the ST that the addition of a doubled gracilis tendon will not result in a four-stranded ACLR graft having a diameter of 8 mm or more. </p><p><br></p><p><strong>Study Design</strong></p><p>Retrospective study, Level IV</p><p><br></p><p><strong>Methods</strong></p><p>A retrospective study was conducted involving patients who underwent 4-strand hamstring ACLR between 2008 and 2018. Cases were excluded if the diameter of the tendons or ACLR graft was missing. The primary outcome was the diameter of two strands of the harvested tendons. A receiver operating characteristic (ROC) analysis was performed to assess the predictability of STx2 on the ACLR graft with a diameter less than 8 mm. The effect of including Gx2 on the final graft size was reported.</p><p><br></p><p><strong>Results</strong></p><p>A total of 314 patients were identified, and the average diameter of STx2 and Gx2 was 6.5+/-0.8 mm and 5.0+/-0.7 mm, respectively. There was a moderate to strong correlation between the diameter of STx2 and Gx2 (p<0.001). STx2 with a diameter less than 6mm predicted a 4-strand ACLR graft of less than 8 mm, with an AUC of 0.917 (p<0.001). When STx2 was less than 6mm, the addition of a doubled gracilis tendon did not result in a 4-strand ACLR graft having a minimal diameter of 8 mm, regardless of the sex of the patient and the diameter of Gx2. </p><p><br></p><p><strong>Conclusion</strong></p><p>When the diameter of a doubled semitendinosus was less than 6 mm, the addition of Gx2 was unlikely to produce a 4-stranded ACLR graft with a diameter of 8 mm or more. Surgeons should consider alternative methods such as tripling or quadrupling the semitendinosus tendon to increase the size of the ACLR graft, rather than routine harvesting the gracilis tendon. </p>