Arthroscopic Rotator Cuff Repair—Transosseous Equivalents Wendell Heard, MD, and Anthony Romeo, MD As attempts have been made to improve rotator cuff healing, transosseous equivalent repairs have garnered interest because they combine strong initial fixation with broad foot print coverage. A number of different suture configurations can be used to secure the rotator cuff repair. Results, particularly in large or massive tears, have been encouraging for the double-row technique. Areas for concern include disruption of the vascular supply to the healing tendon, increased cost and operating room time, and potentially higher risk for tuberosity fracture. Rotator cuff tendon healing is a complex interaction between biomechanical, biological, and patient factors. Although the technique and overall outcomes are still evolving, transosseous rotator cuff repair may offer improvements in the biomechanical stability and clinical outcomes of rotator cuff repairs. Oper Tech Sports Med 20:220-223 © 2012 Elsevier Inc. All rights reserved. KEYWORDS transosseous equivalent, rotator cuff repair, double row
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tructural healing of the rotator cuff tendon to its insertion on the humeral head remains challenging. Ultrasonography and magnetic resonance imaging (MRI) have shown healing rates ranging from 91% in small tears to only 10% in massive tears.1-3 Clinically, patients with larger tears have improved outcomes when tendon healing occurs.4 In an attempt to improve healing, rotator cuff repair techniques have evolved by creating in a laboratory environment a stronger biomechanical construct. Double-row repair techniques added a row of suture anchor fixation lateral to the conventionally placed medial row that had been the standard fixation strategy for arthroscopic rotator cuff repairs. Biomechanical studies showed increased load to failure, improved contact areas and pressures, and decreased gap formation at the tendon-bone interface with double-row constructs.5-9 The theoretical anatomic benefit of double-row rotator cuff repairs is based on work by Oguma et al.10 The authors showed that the potential for woven bone formation to anchor collagen fibers at the bone-tendon interface increases as the available contact area for the fibrovascular tissue interface increases.10 Although better than a single-row fixation, traditional double-row suture anchor repairs do not have the potential increased tendon-bone interface pressure seen with transosseous repairs.11 In an effort to combine the stronger Section of Shoulder and Elbow, Rush University Medical Center, Chicago, IL. Address reprint requests to Anthony Romeo, MD, Section of Shoulder and Elbow, Rush University Medical Center, Chicago, IL. E-mail:
[email protected]
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biomechanical repairs of the double-row construct with the increased tendon-bone interface pressure benefits seen with transosseousrepairs, the “suture bridge” or “transosseous equivalent” (TOE) repairs were developed.12 In TOE repairs, as described by Park et al,12 the suture limbs from the medial row of anchors are incorporated into a lateral row of anchors to create downward pressure and more closely recreate the anatomic rotator cuff footprint. First, the medial row anchors are placed adjacent to the articular surface. Their spacing and number are determined by the size of the tear. The sutures are usually passed approximately 1 cm medial to the tendon edge in mattress fashion, taking care to space the sutures appropriately. The lateral row of anchors is placed where drill holes for a conventional transosseous repair would be (Figs. 1 and 2). Biomechanical studies of open transosseous repairs showed that the optimal initial fixation strength was obtained when the sutures exited at least 1 cm lateral to the greater tuberosity and were tied over a 1-cm bone bridge,13 and this has become the target for the lateral row in TOE rotator cuff repairs.
Biomechanical Data of TOE Techniques Park et al14-16 showed that the ultimate load to failure was significantly higher in the TOE repair than in the conventional double-row repair. Additionally, a significantly larger pressurized area and higher overall pressure were seen in the TOE fixation groups. It is also thought that because the an-
Arthroscopic rotator cuff repair—TOE
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Figure 1 Arthroscopic view of a transosseous equivalent repair.
chors are interconnected in the TOE construct, there is better load sharing and less tension mismatch on individual anchors. As compared with open transosseous repair, the TOE technique has been shown to have comparable initial fixation strength in cadaveric testing,17 and TOE configurations have been shown to maintain force contact over time better than both single- and double-row repairs.18
Figure 2 Transosseous equivalent repair. The medial row of sutures (in this figure, the superior set of sutures) is from a suture anchor placed at the articular margin of the humeral head. These sutures are passed arthroscopically through the tendon in a mattress fashion, but the suture ends are not cut. One suture from each of the mattress sutures is then incorporated into the lateral row of anchors, creating a 4-limb repair with crossing of the sutures. The lateral anchor is typically a knotless interference type of anchor that is placed in the greater trochanter in an area that a traditional open transosseous tunnel would be placed.
A number of variations of the TOE technique have been described. If double-loaded suture anchors are used in a TOE repair, 1 pair of suture from the anterior anchor and 1 pair from the posterior anchor can be passed, tied, and cut in simple fashion to reduce and stabilize the anterior and posterior edges of the rotator cuff cable. The second set of suture from each anchor is then passed and tied in horizontal mattress fashion without cutting the suture ends. One suture from each horizontal mattress is retrieved and incorporated into a knotless anchor on the lateral row anteriorly. The procedure is then repeated for the 2 remaining sutures, which are placed into a knotless anchor on the lateral row posteriorly.19 Spang et al20 described and tested another technique in a sheep infraspinatus model and compared it with a conventional TOE construct. The conventional TOE construct consisted of two 5.5-mm Bio-Corkscrew FT Anchors (Arthrex, Naples, FL) double-loaded with number 2 Fiberwire (Arthrex) for the medial row and SwiveLock insertion anchors (Arthrex) with a closed-end loop for the lateral row. The other anchor technique used 2 open-loop SwivelLock insertions anchors loaded with FiberTape (Arthrex) for the medial row and 2 closed-loop SwivelLock insertion anchors for the lateral row. Biomechanical testing evaluated gap formation, strain, linear stiffness, and ultimate failure load. No significant difference was seen between the conventional and novel TOE constructs in terms of gap formation, strain, linear stiffness, or ultimate failure load.20 Maguire et al21 evaluated the biomechanical behavior of 4 variants of the TOE repair in a sheep model. The first repair was a knotted standard suture bridge with 2 medial 5.5-mm Bio-Corkscrew single-loaded FT Anchors (Arthrex) tied in mattress fashion. Two 3.5-mm PushLock Anchors (Athrex) were used to secure the lateral row, taking 1 suture from each mattress suture. The second repair used a knotted doublesuture bridge and was similar to the first repair except that the medial suture anchors were double loaded. Four medial mattress sutures were used, and all 8 suture strands were incorporated into the lateral row, where they were secured with 2 3.5-mm PushLock Anchors, crossing the 2 sets of
W. Heard and A. Romeo
222 sutures from the middle pair of mattresses. The third repair was an untied suture bridge with 2 medial 5.5-mm Bio-Corkscrew single-loaded FT Anchors (Arthrex), with the sutures passed through the tendon in mattress fashion, but not tied. One strand from each medial mattress was crossed over and secured laterally with 2 3.5-mm PushLock Anchors. The fourth configuration was identical to the third except that 2 3.5 mm PushLock Anchors were used medially instead of Bio-Corkscrew Anchors. The repairs were cyclically loaded and tested to failure. Results showed that the second anchor and suture configuration (knotted double suture bridge) produced the greatest contact area footprint, a greater mean failure load, and no gap formation compared with the other techniques. Among the other 3 techniques, it was determined that there was no significant difference in biomechanical properties of those repairs that used knots versus repairs that did not use knots on the medial row.21 Burkhart et al22 described a self-reinforcing knotless system using anchors and a suture-chain technique to perform an interconnected spanning double-row repair. The medial row anchors (Bio-Corkscrew FT; Arthrex) were preloaded with FiberChain (Arthrex) and placed just lateral to the articular surface. The FiberChain was then passed through the rotator cuff, but not tied, and incorporated into a lateral row of SwivelLock anchors (Arthrex). When compared with the biomechanical properties of double-row fixation in a cadaver model, the yield load and ultimate load were higher in the knotless repair; however, the values were not statistically significant with the knotless repair. Leek et al23 compared the mechanical stability in doublerow rotator cuff repairs between a knotless transtendon construct SutureCross Knotless Anatomic Fixation System (KFx Medical, Carlsbad, CA) and a similar construct with knots on the medial row. A rotator cuff tear was created in a bovine model. In one group, the medial anchors were placed by transtendon passage in a knotless construct that was bridged to a lateral row. In the other group, the medial row anchors were placed directly into the bone medially, the sutures were passed through the tendon, and the sutures were tied before incorporating them into the lateral row. The authors concluded that the creation of medial knots increased the mechanical stability in arthroscopic double-row repair and postulated that medial knots likely improve load sharing with the lateral anchor and suture tendon interface relative to the knotless construct.23 Chu et al24 also found that SutureCross knotless medial row construct had lower biomechanical properties than 2 other TOE constructs with knotted medial rows. Burkhart et al25 have described a “diamondback” suture technique. This is a linked double-row repair using 2 double-loaded Bio-Corkscrew FT suture anchors medially and 3 Bio-SwivelLock C anchors (Arthrex) laterally. The suture configuration provides a pressurized containment grid under the sutures with 3 oblique intersection points. Biomechanical testing focused on pressurized contact area and compared this repair construct with a single-row repair, double-row repair, and a transosseous repair performed without crossing of the sutures. The diamondback repair had the highest initial pressurized contact area, the highest pressurized contact area after 160 minutes
of cyclic testing, and the lowest percentage decrease in pressurized contact area after 160 minutes of testing. The clinical implications of this repair are yet to be determined.
Concerns Surrounding the TOE Repair Concerns have arisen surrounding the use of TOE constructs. Although the blood supply to the tendon is maintained in a TOE repair, increased pressure over the tendon could decrease the blood supply to the healing tendon-bone interface.26 Additionally, there are concerns about increased operating room time, increased cost of additional implants, and overcrowding of implants in the greater tuberosity, making revision surgery more difficult and theoretically increasing the risk of greater tuberosity fracture.11
Outcomes Double-row repairs have a significantly higher rate of healing when compared with single-row repairs in a recent systematic review.27 The difference was more pronounced as the size of the tear increased. Large tears, ⬎3 cm, had a 45% retear rate after single-row repair and a 26% retear rate after doublerow repair. In massive tears, ⬎5 cm, the retear rate was 69% after a single-row repair and 41% after a double-row repair.27 This systematic review did not differentiate between traditional double-row repairs and TOE repairs. Toussaint et al28 reported on the early structural and functional outcomes for 154 arthroscopic TOE rotator cuff repairs. Evaluation was based on MRI or computed tomography arthrogram at a minimum of 12 months after surgery, Constant scores, visual analog pain scales, range of motion, strength, and complications. Postoperative imaging showed that 92% of small tears, 83% of large tears, and 84% of massive tears were intact. Constant scores improved from 44.42 points preoperatively to 80.47 points postoperatively. The mean preoperative pain score improved from 3.83 to 12.77. Mean forward flexion improved from 123.06 to 162.39°. Seventeen patients had postoperative shoulder stiffness. The authors concluded that the clinical outcomes and structural integrity of TOE rotator cuff repairs compare favorably with results reported for other double-row suture anchor repair techniques in short-term follow-up.28 Mihata et al29 studied the structural and functional outcomes after arthroscopic rotator cuff repair in single-row, double-row, and TOE techniques. Using MRI, they found that the retear rate for single-row repair was 10.8%, for double-row repair was 26.1%, and TOE repair was 4.7%. For large and massive rotator cuff tears, the retear rate was 62.5% in single-row constructs, 41.7% in double-row constructs, and 7.5% in TOE constructs. Postoperative clinical outcomes in patients with a retear were lower when compared with patients who had healed tears.29 Frank et al3 performed a nonrandomized clinical study to evaluate repair site integrity in TOE repairs. At a minimum of 1 year postoperatively, MRI assessment of the repairs showed
Arthroscopic rotator cuff repair—TOE an overall healing rate of 88%. Large tears that had supraspinatus and partial or full infraspinatus involvement healed in 86% of patients, whereas isolated supraspinatus tears healed in 89%. The only other study specifically addressing clinical outcome with the suture-bridging repair concluded that the suture-bridge technique resulted in comparable patient satisfaction, functional outcome, and retear rates as compared with double-row procedures.30
Conclusions Rotator cuff repair healing is a complex interaction between biomechanical factors, biological factors, and patient factors. The TOE rotator cuff repair was developed to improve biomechanical factors in hopes of improving healing rates, and thus overall patient outcomes. There are important differences in the clinical outcomes between patients with healed and nonhealed rotator cuff repairs, but further study is needed to conclusively define this difference as well as identify those patients who would be the most ideal candidates for a double-row repair construct.
References 1. Galatz LM, Ball CM, Teefey SA, et al: The outcome and repair integrity of completely arthroscopically repaired large and massive rotator cuff tears. J Bone Joint Surg Am 86-A:219-224, 2004 2. Lafosse L, Brozska R, Toussaint B, et al: The outcome and structural integrity of arthroscopic rotator cuff repair with use of the double-row suture anchor technique. J Bone Joint Surg Am 89:1533-1541, 2007 3. Frank JB, ElAttrache NS, Dines JS, et al: Repair site integrity after arthroscopic transosseous-equivalent suture-bridge rotator cuff repair. Am J Sports Med 36:1496-1503, 2008 4. Harryman DT 2nd, Mack LA, Wang KY, et al: Repairs of the rotator cuff. Correlation of functional results with integrity of the cuff. J Bone Joint Surg Am 73:982-989, 1991 5. Lo IK, Burkhart SS: Double-row arthroscopic rotator cuff repair: Reestablishing the footprint of the rotator cuff. Arthroscopy 19:10351042, 2003 6. Kim DH, Elattrache NS, Tibone JE, et al: Biomechanical comparison of a single-row versus double-row suture anchor technique for rotator cuff repair. Am J Sports Med 34:407-414, 2006 7. Smith CD, Alexander S, Hill AM, et al: A biomechanical comparison of single and double-row fixation in arthroscopic rotator cuff repair. J Bone Joint Surg Am 88:2425-2431, 2006 8. Meier SW, Meier JD: The effect of double-row fixation on initial repair strength in rotator cuff repair: A biomechanical study. Arthroscopy 22:1168-1173, 2006 9. Meier SW, Meier JD: Rotator cuff repair: The effect of double-row fixation on three-dimensional repair site. J Shoulder Elbow Surg 15: 691-696, 2006 10. Oguma H, Murakami G, Takahashi-Iwanaga H, et al: Early anchoring collagen fibers at the bone-tendon interface are conducted by woven bone formation: Light microscope and scanning electron microscope observation using a canine model. J Orthop Res 19:873-880, 2001 11. Dines JS, Bedi A, ElAttrache NS, et al: Single-row versus double-row rotator cuff repair: Techniques and outcomes. J Am Acad Orthop Surg 18:83-93, 2010
223 12. Park MC, Elattrache NS, Ahmad CS, et al: “Transosseous-equivalent” rotator cuff repair technique. Arthroscopy 22:1360e1-5, 2006 13. Caldwell GL, Warner JP, Miller MD, et al: Strength of fixation with transosseous sutures in rotator cuff repair. J Bone Joint Surg Am 79: 1064-1068, 1997 14. Park MC, Idjadi JA, Elattrache NS, et al: The effect of dynamic external rotation comparing 2 footprint-restoring rotator cuff repair techniques. Am J Sports Med 36:893-900, 2008 15. Park MC, ElAttrache NS, Tibone JE, et al: Part I: Footprint contact characteristics for a transosseous-equivalent rotator cuff repair technique compared with a double-row repair technique. J Shoulder Elbow Surg 16:461-468, 2007 16. Park MC, Tibone JE, ElAttrache NS, et al: Part II: Biomechanical assessment for a footprint-restoring transosseous-equivalent rotator cuff repair technique compared with a double-row repair technique. J Shoulder Elbow Surg 16:469-476, 2007 17. Behrens SB, Bruce B, Zonno AJ, et al: Initial fixation strength of transosseous-equivalent suture bridge rotator cuff repair is comparable with transosseous repair. Am J Sports Med 40:133-140, 2012 18. Mazzocca AD, Bollier MJ, Ciminiello AM, et al: Biomechanical evaluation of arthroscopic rotator cuff repairs over time. Arthroscopy 26:592599, 2010 19. Cole BJ, ElAttrache NS, Anbari A: Arthroscopic rotator cuff repairs: An anatomic and biomechanical rationale for different suture-anchor repair configurations. Arthroscopy 23:662-669, 2007 20. Spang JT, Buchmann S, Brucker PU, et al: A biomechanical comparison of 2 transosseous-equivalent double-row rotator cuff repair techniques using bioabsorbable anchors: Cyclic loading and failure behavior. Arthroscopy 25:872-879, 2009 21. Maguire M, Goldberg J, Bokor D, et al: Biomechanical evaluation of four different transosseous-equivalent/suture bridge rotator cuff repairs. Knee Surg Sports Traumatol Arthrosc 19:1582-1587, 2011 22. Burkhart SS, Adams CR, Burkhart SS, et al: A biomechanical comparison of 2 techniques of footprint reconstruction for rotator cuff repair: The SwiveLock-FiberChain construct versus standard double-row repair. Arthroscopy 25:274-281, 2009 23. Leek BT, Robertson C, Mahar A, et al: Comparison of mechanical stability in double-row rotator cuff repairs between a knotless transtendon construct versus the addition of medial knots. Arthroscopy 26:S127S133, 2010 (suppl 9) 24. Chu T, McDonald E, Tufaga M, et al: Comparison of completely knotless and hybrid double-row fixation systems: A biomechanical study. Arthroscopy 27:479-485, 2011 25. Burkhart SS, Denard PJ, Obopilwe E, et al: Optimizing pressurized contact area in rotator cuff repair: The diamondback repair. Arthroscopy 28:188-195, 2012 26. Christoforetti JJ, Krupp RJ, Singleton SB, et al: Arthroscopic suture bridge transosseus equivalent fixation of rotator cuff tendon preserves intratendinous blood flow at the time of initial fixation. J Shoulder Elbow Surg 21:523-530, 2012 27. Duquin TR, Buyea C, Bisson LJ: Which method of rotator cuff repair leads to the highest rate of structural healing? A systematic review. Am J Sports Med 38:835-841, 2010 28. Toussaint B, Schnaser E, Bosley J, et al: Early structural and functional outcomes for arthroscopic double-row transosseous-equivalent rotator cuff repair. Am J Sports Med 39:1217-1225, 2011 29. Mihata T, Watanabe C, Fukunishi K, et al: Functional and structural outcomes of single-row versus double-row versus combined doublerow and suture-bridge repair for rotator cuff tears. Am J Sports Med 39:2091-2098, 2011 30. Voigt C, Bosse C, Vosshenrich R, et al: Arthroscopic supraspinatus tendon repair with suture-bridging technique: Functional outcome and magnetic resonance imaging. Am J Sports Med 38:983-991, 2010