A Tensionable Method for Subscapularis Repair after Shoulder Arthroplasty

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Musculoskeletal Research

Background:

• Lesser tuberosity (LTO) avulsion fractures require robust surgical repair.
• Traditional LTO repair methods using high-strength sutures have limitations.
• A novel tensionable construct with suture tape was developed for LTO repair.

Purpose of the Study:

• To compare the biomechanical properties of a new LTO repair technique using suture tape against a traditional suture repair.
• To evaluate load-to-failure and displacement under cyclic loading.
• To test the hypothesis of no significant difference between the two repair methods.

Main Methods:

• LTO repairs were performed on matched cadaveric shoulders with uncemented humeral stems.
• Group 1: Traditional repair with 4 high-strength #2 sutures.
• Group 2: Novel repair with 2 suture tape loops and a preplaced racking hitch knot.

Main Results:

• The suture tape construct (Group 2) exhibited significantly higher load-to-failure (502.8 N) than the traditional suture repair (Group 1: 209.6 N; P=.018).
• No significant difference in displacement was observed between the groups.
• Failures in Group 1 were primarily due to knot slippage, while Group 2 failures involved tendon tearing.

Conclusions:

• The simplified LTO repair using suture tape and a compression bridge offers favorable biomechanical properties.
• This technique is technically efficient and may provide clinical benefits for LTO repairs.
• The suture tape construct demonstrates superior strength and a different failure mode compared to traditional sutures.