Summary
At 1 year postoperative, remodeling of an ST graft assessed by MRI is better when its distal attachment is left intact. Being older at the time of surgery and having more time elapsed between the injury event and ACL reconstruction surgery were also associated with better graft remodeling.
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 is no data on the remodeling of an attached semitendinosus graft (aST).
Purpose
Compare graft remodeling on MRI at 1-year post-ACL reconstruction between standard free ST graft (ST) and aST. Investigate the effect of the following parameters on SNQ: sex, smoking habits, age at surgery, BMI, time to surgery, time to return to sports, type of sport (in-line, pivot, contact), and addition of lateral tenodesis.
Study design: non-randomized prospective controlled study, level of evidence 3
Methods
180 patients who were undergoing ACL reconstruction were enrolled: 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 (T1-weighted sequence). The secondary endpoints were tibial tunnel widening (TTW), graft maturation (Howell classification), retear rate, new surgery rate, Simple Knee Value (SKV), Lysholm score, functional IKDC, postoperative Tegner score, difference between pre- and postoperative Tegner, 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 (3.42–4.34) in the ST group (P<.001). The following factors were significantly and independently associated with the SNQ: attached ST graft (beta=-2.624668; p<.001), age at the time of surgery (beta=-0.7948476; p=.012) and time elapsed between the injury event and surgery (beta=-0.7137424; p=.046). 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 ; 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=1), SKV (P=.061), postoperative Tegner score (P=.320), pre- to postoperative difference in Tegner score (P=.317), ACL-RSI (P=.097), IKDC (P=.621) and return to sports rate (P=1).
Conclusion
At 1 year postoperative, remodeling of an ST graft assessed by MRI is better when its distal attachment is left intact. Being older at the time of surgery and having more time elapsed between the injury event and ACL reconstruction surgery were also associated with better graft remodeling.