Strength of rotator cuff repair anchors
Leong, Jeremy Zhi Wei
Date of Issue2015-05-18
School of Mechanical and Aerospace Engineering
Arthroscopic suture anchor techniques can be used to repair rotator cuff tendon tear, a common shoulder injury. Unfortunately, in clinical practice, rotator cuff tendon re-tear often occurs after operation. As such, it is essential to assess the biomechanical performance of various anchor repair techniques to find the ideal repair method. The objective of this study was to find out the strength of single-lateral-row rotator cuff repair through biomechanical testing. A full thickness tear of the infraspinatus tendon was simulated in six sheep shoulder specimens and single-lateral-row repair was performed. All six shoulder specimens were mounted onto a fixture, which was custom-designed, and secured onto an Instron machine. The specimens were cyclically loaded between 10 N and 180 N at a rate of 8.33 mm/s for 3000 cycles. Following which, each specimen was pulled to failure at a rate of 1 mm/s. For each specimen, the gap formation at every 500 cycles, ultimate failure load and the mode of failure were recorded. After 3000 cycles, the mean gap formation was 2.44 ± 0.27 mm and the mean ultimate failure load was 452.3 ± 66.3 N. All six repaired shoulder specimens failed by the sutures pulling through their tendons. The results from the present study suggest that single-lateral-row repair has lower fixation strength and can withstand a lower load when compared to the dual-row repair technique. Additionally, the results suggest that rotator cuff repair will fail at the suture-tendon interface before any anchor-related failure occurs.
DRNTU::Engineering::Mechanical engineering::Surgical assistive technology
Final Year Project (FYP)
Nanyang Technological University