Tendon–bone contact pressure and biomechanical evaluation of a modified suture-bridge technique for rotator cuff repair

Abstract

The aim of the study was to evaluate the time-zero mechanical and footprint properties of a suture-bridge technique for rotator cuff repair in an animal model. Thirty fresh-frozen sheep shoulders were randomly assigned among three investigation groups: (1) cyclic loading, (2) load-to-failure testing, and (3) tendon–bone interface contact pressure measurement. Shoulders were cyclically loaded from 10 to 180 N and displacement to gap formation of 5- and 10-mm at the repair site. Cycles to failure were determined. Additionally, the ultimate tensile strength and stiffness were verified along with the mode of failure. The average contact pressure and pressure pattern were investigated using a pressure-sensitive film system. All of the specimens resisted against 3,000 cycles and none of them reached a gap formation of 10 mm. The number of cycles to 5-mm gap formation was 2,884.5 ± 96.8 cycles. The ultimate tensile strength was 565.8 ± 17.8 N and stiffness was 173.7 ± 9.9 N/mm. The entire specimen presented a unique mode of failure as it is well known in using high strength sutures by pulling them through the tendon. We observed a mean contact pressure of 1.19 ± 0.03 MPa, applied on the footprint area. The fundamental results of our study support the use of a suture-bridge technique for optimising the conditions of the healing biology of a reconstructed rotator cuff tendon. Nevertheless, an individual estimation has to be done if using the suture-bridge technique clinically. Further investigation is necessary to evaluate the cell biological healing process in order to achieve further sufficient advancements in rotator cuff repair.

Comparison of Interface Pressure, Contact Surface Area, and Percent Area of Coverage Between Two Suture Configurations for Hill-Sachs Remplissage

“…Baums MH, in 2010, published a study using the same animal model and pressure film to evaluate different configurations of rotator cuff repair. They highlight the similar characteristics between sheep and human rotator cuff tendons [7].…”

“…The variables that were evaluated included the maximum contact pressure (mPa), contact surface area (cm 2 ), and percent defect coverage (%) in each of the models. This instrument has been used in various similar studies, which have demonstrated its effectiveness [7,8,17].…”

Modified Suture-Bridge Technique to Prevent a Marginal Dog-Ear Deformity Improves Structural Integrity After Rotator Cuff Repair

“…11 Since the suture-bridge repair technique was introduced, several biomechanical studies have shown that the suture-bridge method provides more firm repair constructs than do double-row or single-row repair methods. 2,[32][33][34][35] However, clinical results regarding structural healing following suture-bridge repair have been reported in only 2 studies, to our knowledge. 6,25 Choi et al, 6 who conducted a retrospective case series regarding the suture-bridge technique, reported a 17% retear rate in medium-sized to massive rotator cuff tears.…”

Improved Rotator Cuff Footprint Contact Characteristics With an Augmented Repair Construct Using Lateral Edge Fixation

“…Animal studies have previously shown that improving tendonto-bone contact pressure increases tendon healing. 22,28 In previous biomechanical studies, double-row repairs have demonstrated consistently better contact pressures compared with single-row repairs, 3,25 and TOE repairs demonstrate greater contact pressure than double-row repairs. 18 Our study found the classic TOE construct to have contact characteristics similar to those reported by prior studies using a similar experimental setup.…”