Shoulder abduction diminishes self-reinforcement in transosseous-equivalent rotator cuff repair in both knotted and knotless techniques
The self-reinforcement mechanism after double row suturebridge rotator cuff repair generates increasing compressive forces at the tendon footprint with increasing tendon load. Passive range of motion is usually allowed after rotator cuff repair. The mechanism of self-reinforcement could be adversely affected by shoulder abduction.
Rotator cuff tears were created ex vivo in nine pairs of ovine shoulders. Two different repair techniques were used. One group was repaired using a double row ‘suturebridge’ construct with tied horizontal medial row mattress sutures (Knotted repair group). The other group was repaired identically except that medial row knots were not tied (Knotless repair group). Footprint compression was measured at varying amounts of abduction and under tendon loads of 0, 10, 20, 30, 40, 50 and 60N. The rate of increase of contact pressure (degree of self-reinforcement) was calculated for each abduction angle.
Abduction diminishes footprint contact pressure in both knotted and knotless double row suturebridge constructs. Progressive abduction from 0 to 40 abduction in the knotless group and 0–30 in the knotted group results in a decrease in self-reinforcement. Abduction beyond this does not cause a further decrease in self-reinforcement. There was no difference in the rate of increase of footprint contact pressure at each angle of abduction when comparing the knotted and knotless groups.
In the post-operative period, high tendon load combined with minimal abduction would be expected to generate the greatest amount of footprint compression which may improve tendon healing. Therefore, to maximize footprint compression the use of abduction pillows should be avoided while early isometric strengthening should be used.
KeywordsRotator cuff Cuff repair Double row Suturebridge Self-reinforcement Abduction
GS: conceived of the study, participated in its design and coordination and drafted the manuscript. PL: participated in the design of the study, participated in its design and coordination and drafted the manuscript.
The anchors and suture materials used were supplied by Arthrex.
Compliance with ethical standards
Conflict of interest
All authors declare that they have no conflict of interest.
As this was an ex vivo animal experiment, therefore, no IRB approval was required at our institution.
For this type of study, formal consent is not required.
- 6.Smith GCS, Bouwmeester TM, Lam PH (2017) Knotless double-row SutureBridge rotator cuff repairs have improved self-reinforcement compared with double-row SutureBridge repairs with tied medial knots: a biomechanical study using an ovine model. J Shoulder Elbow Surg. https://doi.org/10.1016/j.jse.2017.06.045 CrossRefPubMedGoogle Scholar