This study looks at the dynamic tendon-to-bone contact properties of rotator cuff (RC) repairs—comparing single row repairs (SRR) with double row transosseous- equivalent (TOE) repairs. It was postulated that relaxation during, and movement following, the repair would significantly compromise contact properties and therefore, the ability of the tendon healing.

Simulated tears were created in the supraspinatus tendon of six cadaveric human shoulders. A SRR was then performed using the OPUS System, creating two horizontal mattress sutures. An I-Scan electronic pressure-sensor (Tekscan, Boston, MA) was placed between the supraspinatus tendon and bone. The arm was then rested for 300secs (relaxation) before being passively moved twice through a range-of-motion (0-90 degrees abduction, 0-45 external and 0-45 internal rotation) and finally returned to neutral. The contact properties were recorded throughout each movement. The procedure was then repeated using two TOE techniques: parallel sutures (TOE-P) and a cross over suture pattern (TOE-C).

While peak pressures during the repair were higher in the two TOE repairs, all three methods demonstrated relaxation over 300s such that there was no significant diference in contact pressures at the end of this time. TOE parallel and cross-over repairs demonstrated no significant change in mean TTB contact pressure, force and area during abduction, external rotation and return to neutral, when compared to the 300sec relaxation state. TOE-C demonstrated a higher contact force on internal rotation (+53%). The SRR demonstrated a significant drop in contact force on abduction (−63%), and return to neutral (−43%) and a trend on external rotation (−34%). SRR exhibited no change on internal rotation.

There have been very few biomechanical studies with which observe RC repair contact properties dynamically. Relaxation of the repair can be partially reversed. Significant decrease in contact area with SRR during movement occurred, compared to the TOE repairs, which remains unaltered. This is an important consideration when determining postoperative rehabilitation.

Introduction

Anterior cruciate ligament (ACL) reconstructive surgery is one of the most commonly performed surgical procedures. Synthetic ACL repair surgery with the Lars ligament is designed to repair, rather than replace, the torn ACL. Once the ACL is repaired, the level of function, biomechanical attributes and proprioception should be similar to the pre-injury state.

All patients in this cohort have undergone surgical repair of the torn ACL with synthetic Lars ligament augmentation. The indications and surgical technique will be outlined.

Patients have been assessed at follow-up with KOOS and Marx scores, which reflect the surgical outcome. The preliminary results with a six-month minimum follow-up will be presented. The results reflect previous published studies that show that surgical repair of the torn ACL with Lars ligament augmentation, can reliably and reproducibly stabilise the knee and allow an early return to sport. Complications include one septic arthritis, superficial wound infections and improperly placed bone tunnels.

Synthetic ACL repair using the Lars ligament is a reprodicible technique that allows a rapid post-operative rehabilitation and avoids all complications relating to graft harvesting. The indications and the surgical technique are quite specific and must be adhered to in order to achieve the best results.