Does Suture Depth Affect the Pull-Out Strength of Supraspinatus Repair? A Cadaveric Model
Nadhaporn Saengpetch MD1, Chusak Kijkunasathian MD1, Teerayut Dechmaneenin MD2, Chalermchai Limitlaohaphan MD1
Affiliation : 1 Department of Orthopedics, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand 2 Orthopedics Center, Vejthani Hospital, Bangkok, Thailand
Background : The strength of a supraspinatus tendon repair depends on many factors. One factor, the distance from the
suture-bite to the lateral edge of the repaired tendon, has never been biomechanically evaluated.
Objective : The more medial suture depth to the repaired supraspinatus tendon could obtained the better pull-out strength
compared to the lateral suture-depth distance.
Materials and Methods : Six paired human supraspinatus tendons were harvested and were randomly assigned to be repaired
with Fiberwire® No. 2 at different suture depths (distance from the lateral tendon edge to the suture bite). Biomechanics
properties were tested and modes of failure were noted.
Results : All characteristics of the tendon specimens were normal. Load to failure was found to be proportional to the suture
depth by 19.65 N/mm displacement. A suture depth of 15 mm had the highest load to failure at 275.1+10.5 N (p-value <0.01).
The mode of failure in two of the six 15 mm specimens was suture breakage; the remaining four specimens failed at the suture-
tendon interface.
Conclusion : A suture bite located 15 mm from the lateral tendon edge provides the best possible biomechanical properties
with the lowest failure rate. The most common mode of failure is pull-out at the suture-tendon interface.
Keywords : Supraspinatus tendon repair, Suture depth, Pull-out strength, Mode of failure
