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Introduction: Shoulder motion after rotator cuff repair may result in changes in tension and cont... more Introduction: Shoulder motion after rotator cuff repair may result in changes in tension and contact pressure at the repair site. Our goal was to determine how tension and motion affect a repair and what type of repair best tolerates these variables. Methods: Rotator cuff tears were created ex vivo in 30 ovine shoulders divided into 5 groups: single-row repair, double-row repair, tension-band repair, suture bridge repair, and double-row tension-band repair. A pressure probe was passed through a hole created in the footprint to dynamically measure footprint pressure. The rotator cuffs were repaired, and contact pressure was measured with variable tension placed on the repaired tendon from 10 to 30 N and variable shoulder abduction from À10 to þ10. Repair strength was determined by use of a pull-to-failure test. Results: Increasing tension on the repaired tendon resulted in an increase in contact pressure whereas increasing the abduction angle resulted in a decrease in contact pressure in all 5 groups. For all abduction and tension combinations, the suture-bridge and double-row tension band groups recorded the highest contact pressures (P < .05), followed by the tension-band, single-row, and double-row repairs. Load to failure was greatest for the 2 double-row techniques, followed by the tension-band, suture-bridge, and single-row repairs. Discussion: Contact pressure increases as tension increases across the repair and decreases as the shoulder is abducted. The double-row tension-band rotator cuff repair showed the best combination of contact pressure and repair strength. Level of evidence: Basic Science Study, Animal Model.
Arthroscopy: The Journal of Arthroscopic & Related Surgery, 2010
Purpose: The purpose of this study was to determine whether transtendon repair by use of a novel ... more Purpose: The purpose of this study was to determine whether transtendon repair by use of a novel small-diameter knotless anchor showed enhanced mechanical properties compared with tear completion and repair. Methods: Articular-sided partial-thickness tears were created ex vivo in the infraspinatus of 24 ovine shoulders. The specimens were randomized into 4 groups of 6 each: (1) no repair, (2) transtendon repair, (3) completion of tear with tension-band single-row repair, and (4) completion of tear with double-row repair. Footprint contact pressure and ultimate load to failure were measured in each specimen. Results: Technical failure of the transtendon anchors occurred in 3 of 15 shoulders. Transtendon repair (mean Ϯ SEM, 0.8 Ϯ 0.1 MPa) and double-row repair (1 Ϯ 0.09 MPa) showed 3-fold (P Ͻ .001) greater footprint contact pressures than tension-band single-row repair (0.3 Ϯ 0.03 MPa) and no repair (0.3 Ϯ 0.02 MPa). The ultimate load to failure for transtendon repair (544 Ϯ 22 N) was more than 3 times greater than that for the double-row repair (157 Ϯ 23 N) (P Ͻ .001) and the single-row repair (116 Ϯ 11 N) (P Ͻ .001). Conclusions: Transtendon repair of partial-thickness tears by use of specifically designed anchors biomechanically outperformed tear completion and repair in an ovine model. Transtendon repair showed the best combination of high footprint contact pressure and high ultimate failure load. However, the high insertion failure rate of these transtendon anchors is of concern. Clinical Relevance: On the basis of the biomechanical data, transtendon repair of partial-thickness rotator cuff tears may be used as an alternative to tear completion and repair, but the specific transtendon anchors used in this study need further evaluation before their clinical use can be recommended.
Introduction: Shoulder motion after rotator cuff repair may result in changes in tension and cont... more Introduction: Shoulder motion after rotator cuff repair may result in changes in tension and contact pressure at the repair site. Our goal was to determine how tension and motion affect a repair and what type of repair best tolerates these variables. Methods: Rotator cuff tears were created ex vivo in 30 ovine shoulders divided into 5 groups: single-row repair, double-row repair, tension-band repair, suture bridge repair, and double-row tension-band repair. A pressure probe was passed through a hole created in the footprint to dynamically measure footprint pressure. The rotator cuffs were repaired, and contact pressure was measured with variable tension placed on the repaired tendon from 10 to 30 N and variable shoulder abduction from À10 to þ10. Repair strength was determined by use of a pull-to-failure test. Results: Increasing tension on the repaired tendon resulted in an increase in contact pressure whereas increasing the abduction angle resulted in a decrease in contact pressure in all 5 groups. For all abduction and tension combinations, the suture-bridge and double-row tension band groups recorded the highest contact pressures (P < .05), followed by the tension-band, single-row, and double-row repairs. Load to failure was greatest for the 2 double-row techniques, followed by the tension-band, suture-bridge, and single-row repairs. Discussion: Contact pressure increases as tension increases across the repair and decreases as the shoulder is abducted. The double-row tension-band rotator cuff repair showed the best combination of contact pressure and repair strength. Level of evidence: Basic Science Study, Animal Model.
Arthroscopy: The Journal of Arthroscopic & Related Surgery, 2010
Purpose: The purpose of this study was to determine whether transtendon repair by use of a novel ... more Purpose: The purpose of this study was to determine whether transtendon repair by use of a novel small-diameter knotless anchor showed enhanced mechanical properties compared with tear completion and repair. Methods: Articular-sided partial-thickness tears were created ex vivo in the infraspinatus of 24 ovine shoulders. The specimens were randomized into 4 groups of 6 each: (1) no repair, (2) transtendon repair, (3) completion of tear with tension-band single-row repair, and (4) completion of tear with double-row repair. Footprint contact pressure and ultimate load to failure were measured in each specimen. Results: Technical failure of the transtendon anchors occurred in 3 of 15 shoulders. Transtendon repair (mean Ϯ SEM, 0.8 Ϯ 0.1 MPa) and double-row repair (1 Ϯ 0.09 MPa) showed 3-fold (P Ͻ .001) greater footprint contact pressures than tension-band single-row repair (0.3 Ϯ 0.03 MPa) and no repair (0.3 Ϯ 0.02 MPa). The ultimate load to failure for transtendon repair (544 Ϯ 22 N) was more than 3 times greater than that for the double-row repair (157 Ϯ 23 N) (P Ͻ .001) and the single-row repair (116 Ϯ 11 N) (P Ͻ .001). Conclusions: Transtendon repair of partial-thickness tears by use of specifically designed anchors biomechanically outperformed tear completion and repair in an ovine model. Transtendon repair showed the best combination of high footprint contact pressure and high ultimate failure load. However, the high insertion failure rate of these transtendon anchors is of concern. Clinical Relevance: On the basis of the biomechanical data, transtendon repair of partial-thickness rotator cuff tears may be used as an alternative to tear completion and repair, but the specific transtendon anchors used in this study need further evaluation before their clinical use can be recommended.