Isolating Suture Slippage During Cadaveric Testing of Knotless Anchors.

We evaluated a testing method designed to isolate and analyze the effectiveness of different suture-retention mechanisms in knotless suture anchors used for rotator cuff repairs. Six knotless PushLock implants (Arthrex) with a suture-retention mechanism dependent on a press-fit of suture between the anchor's outer diameter and surrounding bone were compared with 6 ReelX STT devices (Stryker) reliant on an intrinsic suture-locking mechanism. Suture slippage beyond minimal clinical failure thresholds, as well as ultimate failure load, were determined with a novel testing fixture that isolated suture slippage. Suture slippage was isolated from anchor-bone disengagement. Each PushLock exhibited suture slippage of more than 3 mm, and each ReelX exhibited slippage of less than 3 mm. The PushLock implants also exhibited significantly (P < .05) more interval and maximum slippage; 5 of these 6 implants failed via complete suture slippage before dynamic testing could be completed. All ReelX devices survived dynamic testing and ultimately failed via suture breakage. This novel axial load biomechanical testing technique isolated suture slippage in 2 uniquely designed knotless anchors. The press-fit PushLock implant was prone to slippage failure, whereas the ReelX device with its internal suture-locking mechanism exhibited minimal slippage.

[1]  Bryan T. Hanypsiak,et al.  Biomechanical Validation of Load-Sharing Rip-Stop Fixation for the Repair of Tissue-Deficient Rotator Cuff Tears , 2014, The American journal of sports medicine.

[2]  H. Shin,et al.  Comparison of Repair Integrity and Functional Outcomes for 3 Arthroscopic Suture Bridge Rotator Cuff Repair Techniques , 2013, The American journal of sports medicine.

[3]  E. McCarty,et al.  Knotless single-row rotator cuff repair: a comparative biomechanical study of 2 knotless suture anchors. , 2012, Orthopedics.

[4]  S. Baek,et al.  Functional outcomes and structural integrity after double-pulley suture bridge rotator cuff repair using serial ultrasonographic examination. , 2012, Journal of shoulder and elbow surgery.

[5]  C. Gerber,et al.  Suture slippage in knotless suture anchors as a potential failure mechanism in rotator cuff repair. , 2012, Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association.

[6]  Y. Rhee,et al.  Arthroscopic Rotator Cuff Repair Using Modified Mason-Allen Medial Row Stitch , 2012, The American journal of sports medicine.

[7]  W. Walsh,et al.  Biomechanical evaluation of four different transosseous-equivalent/suture bridge rotator cuff repairs , 2011, Knee Surgery, Sports Traumatology, Arthroscopy.

[8]  Leslie J. Bisson,et al.  A biomechanical comparison of the pullout strength of No. 2 FiberWire suture and 2-mm FiberWire tape in bovine rotator cuff tendons. , 2010, Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association.

[9]  J. Bynum,et al.  Comparative testing by cyclic loading of rotator cuff suture anchors containing multiple high-strength sutures. , 2010, Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association.

[10]  P. Müller,et al.  Biomechanical stability of knotless suture anchors used in rotator cuff repair in healthy and osteopenic bone. , 2010, Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association.

[11]  G. Osterhoff,et al.  Biomechanical Evaluation of Knotless Anatomical Double-Layer Double-Row Rotator Cuff Repair , 2009, The American journal of sports medicine.

[12]  J. Schoolfield,et al.  A biomechanical comparison of 2 techniques of footprint reconstruction for rotator cuff repair: the SwiveLock-FiberChain construct versus standard double-row repair. , 2009, Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association.

[13]  G. Murrell,et al.  Open versus Two Forms of Arthroscopic Rotator Cuff Repair , 2009, Clinical orthopaedics and related research.

[14]  Vincent H. Key,et al.  Initial fixation and cyclic loading stability of knotless suture anchors for rotator cuff repair. , 2008, Journal of shoulder and elbow surgery.

[15]  Neal S ElAttrache,et al.  Arthroscopic rotator cuff repairs: an anatomic and biomechanical rationale for different suture-anchor repair configurations. , 2007, Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association.

[16]  D. Coons,et al.  Cyclic load testing of biodegradable suture anchors containing 2 high-strength sutures. , 2007, Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association.

[17]  M. Yeh,et al.  Strength of damaged suture: an in vitro study. , 2006, Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association.

[18]  Andrew Mahar,et al.  Failure mode of suture anchors as a function of insertion depth. , 2003, The American journal of sports medicine.

[19]  C. Gerber,et al.  Mechanical Strength of Arthroscopic Rotator Cuff Repair Techniques: An in Vitro Study , 2002, The Journal of bone and joint surgery. American volume.

[20]  R. Thal,et al.  A Knotless Suture Anchor , 2001, The American journal of sports medicine.

[21]  S S Burkhart,et al.  A stepwise approach to arthroscopic rotator cuff repair based on biomechanical principles. , 2000, Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association.

[22]  C Gerber,et al.  Mechanical strength of repairs of the rotator cuff. , 1994, The Journal of bone and joint surgery. British volume.