Comparison of the retear rate 2 years after ACL reconstruction with the Tape Locking Screw short graft system and the STG technique: A case control study with propensity score matching

Abstract

Purpose

Theoretically, short semitendinosus grafts result in less pain and morbidity while providing greater knee flexion strength and sparing the gracilis tendon. They often require the use of blind bone tunnels as well as fixation at both ends of the graft with suspensory cortical buttons. The “Tape Locking Screw” (TLS) system is another option. There are few studies comparing ACL reconstruction with a short graft using the 4-strand semitendinosus graft (ST4-TLS) technique with that of the semitendinosus-gracilis (STG) procedure. This study was designed: (1) to compare the retear rate following these two technics after 2 years of follow-up, (2) to compare the clinical scores, complications and return to sport times between the two procedures Q1, Q2.

Hypothesis

Our hypothesis was that there would be no differences in retear rates between the two techniques.

Methods

This single center case control study included 290 patients who underwent STG reconstruction that were paired by propensity score matching to 299 patients who underwent ST4-TLS reconstruction. The main evaluation criterion was the retear rate 2 years after surgery. Secondary criteria were the two-year postoperative complication rate, the time to return to sport, to pivot sports and to running, as well as the complication rates and clinical scores 6 months, 1 year and 2 years after surgery.

Results

At the final follow-up, the overall retear rate in our series of ACL ligament reconstruction was 6.0% (36/596). There was no difference in retear rates between the groups 2 years after ligament reconstruction [ST4-TLS: 6.7% (20/299) vs. STG: 5.4% (16/297); p = 0.47]. The postoperative KOOS symptom score and the Tegner score were found to be better in the STG group at 1 year (81 vs. 78, p = 0.008) and 2 years (5.64 vs. 5.10, p = 0.016), respectively, representing the minimally clinically important difference (MCID) for the latter. No difference was found in the other clinical scores 6 months, 1 year or 2 years after surgery. There was no significant difference in the return to sport [TLS: 93.0% (164/299) vs. STG: 93.0% (158/297) p = 0.99] or the complication rate [TLS: 8.7% (26/299) vs. STG: 7.4% (22/297) p = 0.89] between the groups.

Discussion

The ST4-TLS ACL ligament reconstruction technique was found to be as reliable as the standard STG procedure 2 years after surgery for the retear rate and the return to sport, although the results of certain postoperative clinical scores seem to be lower.

Level of evidence

III; case control study.