A Novel Method for Reducing Gap Formation in Tendon Repair RYAN - PowerPoint PPT Presentation

A Novel Method for Reducing Gap Formation in Tendon Repair RYAN DEAN, MS4 N E W YO R K M E D I C A L C O L L E G E PAUL SETHI, MD O R T H O PA E D I C N E U R O S U R G E RY S P E C I A L I S T S

Gap Formation Distance between repaired tendon and fixation point. Develops after repair is subjected to tension. Secure fixation between the tendon and bone is critical for clinical success of the tendon repair 1,2 . Early rehabilitation protocols are dependent on resistance to gap formation. 1,2,3,4

Why Does Gap Formation Occur? Understanding the mechanism to help facilitate innovation: ◦ Tendon Repair Technology ◦ Rehabilitation Proposed Mechanisms: 1. Tear-Out 2. Material Elasticity 3. Slack

Understanding “Slack” When tensioned, suture constricts the compressible tendon. ◦ Leads to extrusion of suture from tendon end  Gap Formation Occurs ◦ Unavoidable with current techniques ◦ Not a result loose knot throws ◦ Gap remains after tension is released.

Designing for Slack Removal Challenges in Removing Slack with Current Method: 1. Krackow is a Locking Stitch 2. Substantial Tension is Required for Slack Removal ◦ Currently Impractical in the OR Traditional Krackow

Designing for Slack Removal Tension-Assist Loop 1. Overcoming the Locking Design ◦ Tension applied from 2 directions ◦ More efficient tensioning 2. Appling Substantial Tension Safety ◦ “Suture-to-Suture” tensioning ◦ No longer “Suture-to-Patient” Krackow with TAL

The Tension-Assist Loop Method Stitch the TAL Krackow Apply Bi-Directional Tension Slack Now Reduced 250 N (56 lbs)

The Tension-Assist Loop Method Cut Loop and Tie TAL Krackow Traditional Krackow

Methods – Comparison to Traditional Krackow 4 groups of 8 porcine tendons each: ◦ TAL Krackow: #2 FiberWire ◦ Traditional Krackow: 1. #2 FiberWire 2. FiberTape Gap 3. LabralTape Each group cyclically loaded to 200 N (45 lbs) 200 times Gap measured under tension of 200 th load 200 th Load Before Loading

Results TAL Method resulted in 75% less gap formation compared to Krackow with same suture material. Additional studies show consistent results (>10 • mm) with traditional Krackow with #2 FiberWire. 4,6 5mm gap considered clinical failure. 7 • Many consider the Krackow the gold standard. 4 •

Conclusions The Tension-Assist Loop Method is one way to achieve less gap formation in the lab. Results suggest Slack a significant mechanism in gap formation. Identifying the significant mechanism may help facilitate future innovation in tendon repair. A handheld device may be feasible for application of TAL in the OR. ◦ Additional Leverage

References 1. Kearney RS, Costa ML. Current concepts in the rehabilitation of an acute rupture of the tendo Achilis. J Bone Joint Surg Br. 2012;94:28-31 2. Maffulli N, Tallon C, Wong J, et al. Early weightbearing and ankle mobilization after open repair of acute midsubstance tears of the Achilles tendon. Am J Sports Med. 2003;31;692-700 3. Yostsumoto T, Miyamoto W, Uchio Y. Novel approach to repair of acute Achilles tendon rupture; early recovery without postoperative fixation or orthosis. Am J Sports Med. 2010;38:287-292 4. Hahn J, Inceoglu S, Wongworawat M. Biomechanical Comparison of Krackow Locking Stitch Versus Nonlocking Loop Stitch With Varying Number of Throws. Am J Sports Med. 2014;42:3003-3008 5. Schmidt C, Diaz A, Weir D. Repaired distal biceps magnetic resonance imaging anatomy compared with outcome. Journal of Shoulder and Elbow Surgery. 2012;21:1623-1631 6. McKeon BP, Heming JF, Fulkerson J, Langeland R. The Krackow stitch: a biomechanical evaluation of changing the number of loops versus the number of sutures. Arthroscopy. 2006;22(1):33–37 7. Lee S, Goldsmith S, Nicholas S. Optimizing Achilles Tendon Repair: Effect of Epitendinous Suture Augmentation of the Strength of Achilles Tendon Repairs. Foot & Ankle International 2008;29:427-432 8. http://eorthopod.com/distal-biceps-rupture

Thank you Questions