Preserving the Semitendinosus Distal Attachment Is Associated With Improved Graft Remodeling After ACL Reconstruction

Abstract

Background: The semitendinosus (ST) tendon can be used by itself as a graft for anterior cruciate ligament (ACL) reconstruction. An increasing number of these procedures are being done while preserving the ST's tibial attachment, but there are no data on the remodeling of an attached ST (aST) graft. Purpose: To compare graft remodeling on magnetic resonance imaging (MRI) scans at 1 year after ACL reconstruction between standard free ST graft and aST graft. Study design: Cohort study; Level of evidence, 3. Methods: This prospective study enrolled 180 patients who were undergoing ACL reconstruction: 90 with the ST graft and 90 with the aST graft. The analysis was performed 1 year after the surgery. The main endpoint was the signal-to-noise quotient (SNQ) on MRI scans (T1-weighted sequence). The secondary endpoints were tibial tunnel widening (TTW), graft maturation (Howell classification), retear rate, new surgery rate, Simple Knee Value, Lysholm score, International Knee Documentation Committee (IKDC) score, postoperative Tegner score, difference between pre- and postoperative Tegner scores, ACL–Return to Sport after Injury (ACL-RSI), return-to-sports rate, and time to return to sports. Results: The mean adjusted SNQ was 1.18 (95% CI, 0.72-1.65) in the aST group and 3.88 (95% CI, 3.42-4.34) in the ST group ( P < .001). The new surgery rate was 2.2% in the aST group and 10% in the ST group ( P = .029). The median Lysholm score was significantly higher in the aST group (99; interquartile range [IQR], 95-100) than in the ST group (95; IQR, 91-99) ( P = .004). The mean time to return to sports was significantly shorter in the aST group (248.73 ± 141.62 days) than the ST group (317.23 ± 144.69 days) ( P = .002). No statistically significant difference was found between groups in the TTW ( P = .503), Howell graft maturity grade ( P = .149), retear rate ( P > .999), Simple Knee Value ( P = .061), postoperative Tegner score ( P = .320), pre- to postoperative difference in Tegner score ( P = .317), ACL-RSI ( P = .097), IKDC score ( P = .621), and return-to-sports rate ( P > .999). Conclusion: At 1 year postoperatively, remodeling of an ST graft assessed using MRI is better when its distal attachment is left intact.