Summary

The TLS method of graft preparation provides an exceptionally reliable graft diameter with no harvests resulting in a graft under 8mm. In almost all cases this was achieved without supplementing with a gracilis autograft. The results at two years show excellent patient related outcome with a low rate of revision.

Abstract

Background

The Tape locking screw (TLS) system is a novel ACLR method and is gaining increasing popularity. The TLS system uses a shorter graft (50-60mm) prepared from a single hamstring tendon (semi-tendinosus) sparing the gracilis. The graft is looped around two polyethylene tapes resulting in a 4 or 5 stranded graft, prepared with sutures and pre-tensioned. 4.5mm tunnels are reamed outside in with power reamers and bone recesses established using retrograde hand reamers. The graft is drawn into the bone recesses via the tapes establishing a press-fit and then fixed by screwing the suspension tapes in place with dedicated interference screws. Purported benefits of the system include; reliable graft thickness, reduced donor site morbidity due to harvesting of only the semi-tendinosus tendon, durable fixation, short length of the suspension construct which is thought to limit tunnel widening, and improved contact of the graft with the tunnel walls. A case-series has been published as part of a technical description of the technique and showed minimal anteroposterior translation post-operatively but did not report any patient related outcome measures. There are few other published clinical studies in the English language literature. We report the results of a group of patients who have completed 2-year follow-up.

Methods

Patients operated with the TLS ACLR who had completed 2-year follow-up were selected from the senior surgeon’s database. Graft dimensions, Knee injury and osteoarthritis outcome score (KOOS), Western Ontario and Mcmaster Universities Osteoarthritis index (WOMAC), Lysholm score and Tegner activity scale were evaluated.

Results

168 patients were identified. Twelve cases with concomitant grade II-III medial collateral ligament injury were excluded leaving a total of 156. Mean age was 27 (SD 10). 92 were male and 64 female. The mean graft diameter was 9mm (SD 0.7) with all grafts recorded being =8mm in diameter. 139 (90.3%) of grafts required harvest of only the semitendinosus tendon, sparing the gracilis. 34 (21.8%) patients were lost-to-follow-up. There was a statistically significant difference in pre-operative and 2-year KOOS (all subscales), WOMAC and Lysholm scores (p=0.000). 5 patients (4.1%) suffered a graft rupture during the two years of follow-up.

Conclusion

The TLS method of graft preparation provides a very reliable graft diameter with no harvests resulting in a graft under 8mm. In almost all cases this was achieved without supplementing with a gracilis autograft. The results at two years show excellent patient related outcome with a low rate of revision.