Arthroscopic Rotator Cuff Repair—Traditional Anchor Techniques

Arthroscopic Rotator Cuff Repair—Traditional Anchor Techniques

Arthroscopic Rotator Cuff Repair—Traditional Anchor Techniques Emilie V. Cheung, MD, and Marc R. Safran, MD Initial fixation strength and minimal gap ...

2MB Sizes 1 Downloads 105 Views

Arthroscopic Rotator Cuff Repair—Traditional Anchor Techniques Emilie V. Cheung, MD, and Marc R. Safran, MD Initial fixation strength and minimal gap formation are thought to be important concepts for optimization of rotator cuff tendon healing. Failure of rotator cuff healing after repair has been reported to be relatively high. This suggests that traditional repair techniques fail to restore a sufficient healing environment. Traditional arthroscopic rotator cuff repairs are performed using a single row of suture anchors along the greater tuberosity. Anatomically, there is theoretical benefit of double-row repairs because techniques that increase the surface area between the tendon and bone will potentially have higher rates of structural healing. There have been significant advances in arthroscopic techniques and instrumentation for the past decade. Suture anchor design, insertion technique, and configuration are important biomechanical factors and are the subjects of recent studies. Clinical studies have failed to show superior functional outcomes or healing rates when comparing singlewith double-row techniques, and there are some concerns about vascularity of the tendon using some of these double-row techniques. This article reviews the biomechanical basis of rotator cuff tear and repair, and surgical technique of rotator cuff repair, outcome of arthroscopic rotator cuff repair, and important considerations in rotator cuff repair, including tear pattern recognition, marginal convergence, and suture technique. Oper Tech Sports Med 20:213-219 © 2012 Elsevier Inc. All rights reserved. KEYWORDS arthroscopic rotator cuff repair, anchors, shoulder, suture anchors, suture, rotator cuff fixation

S

ince Codman’s first description in 1911, our understanding of rotator cuff pathology and our ability to repair rotator cuff tears have greatly improved. Degenerative rotator cuff tears are one of the most common causes of shoulder pain in the aging population. Although often multifactorial, rotator cuff tears commonly result from age-related degeneration of the tendon. Imaging studies have revealed that 30% of asymptomatic people ⬎60 years of age and 65% of asymptomatic people ⬎70 years of age have rotator cuff tears.1,2 Degenerative rotator cuff tears typically start with the articular surface of the anterior margin of the supraspinatus (SS) and may progress to become a full-thickness tear.3,4 The tear may then extend into the infraspinatus and subscapularis. The goal of arthroscopic rotator cuff repair is to achieve anatomic reduction of the musculotendinous cuff over its anatomic footprint. Biological healing potential is optimized when there is a strong repair construct.

Department of Orthopedic Surgery, Stanford University, Stanford, CA. Address reprint requests to Marc R. Safran, MD, Department of Orthopedic Surgery, Stanford University, 450 Broadway, M/C 6342, Redwood City, CA 94063. E-mail: [email protected]

1060-1872/12/$-see front matter © 2012 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1053/j.otsm.2012.08.002

The clinical results reported with arthroscopic repair are equivalent to those reported for open and mini-open techniques. However, the main benefits of arthroscopic techniques include better visualization of the tear pattern, quicker recovery time, less pain, and no deltoid detachment. Our overall ability to repair the rotator cuff arthroscopically has improved greatly for the past decade because of technological advances in instrumentation and the refinement of arthroscopic techniques.

Pathoanatomy The anatomy of the rotator cuff footprint has been studied in cadaveric studies.5 The SS has a trapezoidal footprint measuring approximately 25 mm from anterior to posterior and 14 mm from medial to lateral. Thus, the total surface area available for healing of the SS is about 350 mm2. The infraspinatus inserts onto a larger area of the greater tuberosity, and its footprint is located just adjacent and posterior to the SS, but in continuity with the SS. The rotator cuff footprint has been described as the “healing zone.” When performing arthroscopic repair, it is important to recreate this normal insertional anatomy. This is thought to increase the tendon-to-bone contact area so that the maximum surface area is available for healing. 213

214 The normal bone-to-tendon interface involves the interdigitation of layers of intact oriented type I collagen fibers to a continuous insertion on the humerus.6 The vasculature is organized and dispersed throughout the tendon; vessels decrease in size and number because the distance to the bone decreases. Longitudinally, there are 4 distinct zones of tissue: tendon, nonmineralized fibrocartilage, mineralized fibrocartilage, and bone. Tendon-to-bone healing after rotator cuff repair begins with the formation of fibrovascular tissue.7 Bone then grows into this tissue, and collagen is formed along the repair site. In normal bone-to-tendon healing, the final bone-to-tendon insertional transitions ultimately have little resemblance to the native insertion site, instead of 4 distinct zones, the bone and tendon are joined by a layer of fibrovascular scar tissue predominated by type III collagen. This tissue is weaker than the original insertion site and may contribute to repair failures. Initial fixation strength and minimal gap formation are thought to be important concepts for optimization of rotator cuff tendon healing. Failure of rotator cuff healing after repair has been reported to be relatively high. This suggests that traditional repair techniques fail to restore a sufficient healing environment. Traditional arthroscopic rotator cuff repairs are performed using a single row of suture anchors along the greater tuberosity. Anatomically, there is theoretical benefit of double-row repairs because techniques that increase the surface area between the tendon and bone will potentially have higher rates of structural healing. There have been significant advances in arthroscopic techniques and instrumentation for the past decade. Suture anchor design, insertion technique, and configuration are important biomechanical factors and are the subjects of recent studies. The clinical use of single-row and double-row techniques and their relationship to tendon healing and clinical outcomes have also been studied. Double-row repair techniques, which use a medial row and a lateral row of suture anchors in the repair configuration, are a relatively new innovation in rotator cuff surgery. In double-row repairs, a linear row of anchors is placed medially along the articular margin. A second row is placed along the lateral aspect of the rotator cuff footprint on the greater tuberosity. This configuration is thought to recreate the normal anatomic footprint and increases the surface area for which the tendon can heal to bone. Double-row techniques have been shown to have superior biomechanical fixation strength than single-row configurations. More favorable load to failure, improved contact areas and pressures, and decreased gap formation have been reported with double-row techniques when compared with single-row techniques. However, clinical studies have failed to show superior functional outcomes or healing rates when comparing single- with double-row techniques, and there are some concerns about vascularity of the tendon using some of these techniques.

Surgical Technique The beach chair or lateral position may be used, based on surgeon preference. We prefer the beach chair position to facilitate visual orientation of the rotator cuff tear and its

E.V. Cheung and M.R. Safran relationship to the footprint. We place the arm into a holding device (such as the McConnell arm holder [McConnell Orthopaedics, Greenville, TX] or the Spider attachment [Tenet Medical Engineering, Calgary, Canada]) to maintain the arm in optimal position determined during arthroscopy. The bony landmarks are marked with a pen: the coracoid, scapular spine, acromion, clavicle, and acromioclavicular joint. A posterior viewing portal is created at the “soft spot,” 2 cm inferior and 2 cm medial to the posterolateral corner of the acromion. A standard glenohumeral diagnostic arthroscopy is performed. The status of the subscapularis, glenohumeral ligaments, labrum, articular surfaces, and biceps tendon is documented. The axillary pouch is visualized to rule out the presence of loose bodies. The rotator cuff is then evaluated from viewing within the glenohumeral joint. The surgeon can estimate the coronal and sagittal plane dimensions of the articular portion of the rotator cuff tear. For example, a medial to lateral loss of cuff attachment of approximately 6-8 mm represents a 50% partial-thickness rotator cuff tear.5 The rotator cuff tear may be marked with a spinal needle and a number 1 monofilament suture inserted from a lateral percutaneous portal. Later, this suture may be easily identified within the subacromial space to locate the rotator cuff tear. In the presence of a full-thickness rotator cuff, the footprint is debrided first through a high anterior lateral portal. This anterior lateral portal is created at the lateral border of the rotator interval adjacent to the biceps tendon. Then, a lateral portal is created and further debridement of the rotator cuff footprint is performed through the tear (Fig. 1A and B). Next, the arthroscope is removed and reintroduced into the subacromial space through the posterior portal. A complete subacromial bursectomy is performed to achieve clear visualization of the rotator cuff tear from the bursal surface. After debridement of the rotator cuff tear margin as well as the rotator cuff footprint, the tear size can be more clearly assessed. The amount of exposed rotator cuff footprint and the dimension of the tear are noted. Soft tissue is removed from the undersurface of the acromion, and the coracoacromial ligament is released to maximize the relative working space in the subacromial space. If the undersurface of the acromion is prominent or spurred, decreasing the subacromial working space, an acromioplasty is performed using a burr through the lateral portal. Viewing in the subacromial space may then be performed from creation of a new posterolateral portal or alternatively, a direct lateral portal, based on surgeon preference. The arm may be externally rotated to optimize visualization of the tear. The geometry of the tear and quality of the tendon tissue are documented. Burkhart et al8 have described rotator cuff tear geometry into the following categories: crescent-shaped, U-shaped, and L-shaped tears (Figs. 2, 3, and 4). Crescent-shaped tears have good medial to lateral mobility and can be repaired to bone with minimal tension. U-shaped tears extend much more medially, with the apex of the tear near the glenoid rim. L-shaped tears are similar to U-shaped tears, except that one of the leaves is more mobile that the other and there is a longitudinal split in the tendon tissue. In the setting of a U-shaped or

Traditional anchor techniques for cuff repair

215

Figure 1 (A) Right shoulder viewed from the posterior viewing portal. The articular surface of a full-thickness rotator cuff tear is visualized. (B) The rotator cuff footprint has been debrided. (C) The same rotator cuff tear is now visualized from a subacromial viewing portal. (D) The completed rotator cuff repair using transosseous-equivalent suture-bridge technique.

L-shaped tear, it is important to decrease the tear volume by placement of margin convergence sutures. Margin convergence sutures are sequential side-to-side sutures placed from medial to lateral of the anterior and posterior leaves of a U-shaped tear. In an L-shaped tear, the margin convergence sutures are placed along the longitudinal split. Because the margin convergence sutures are tied down, the free margin of the rotator cuff converges toward the footprint on the greater tuberosity. The lateral margin of the cuff tissue can then be repaired to the footprint with decreased strain at the repair site. Excursion of the tear is performed by using an arthroscopic grasping device to assess how the tendon tissue will best cover the rotator cuff footprint. Excursion may be optimized by performing bursal-sided releases with the shaver or electrocautery wand. The grasping device may also be used to perform a trial reduction of the tendon tissue over the rotator cuff footprint. Often times, it is not only the medial to lateral vector but also the posterior to anterior vector of tendon excursion that needs to be checked. If the SS tear is

retracted in a medially and posteriorly displaced position, then pulling the edge of the tendon in a laterally and anteriorly directed vector may give the best coverage over the footprint and to minimize any unnecessary tension at the repair site. The points of fixation can be planned while the torn tendon is held in its reduced position, and the surgeon can plan the type of suture and anchor configuration. A spinal needle is used to localize anchor placement, and 7.0- to 8.0-mm threaded cannulas are used for the anterior and lateral portals for suture passage, instrumentation, and knot tying.

Single-Row Versus DoubleRow Suture Anchor Fixation The quality of the tendon may sometimes affect whether a single- or double-row configuration should be used. If the tendon quality or excursion is poor, then the surgeon may opt to perform a single-row repair to minimize undue tension

E.V. Cheung and M.R. Safran

216

Figure 2 (A) Superior view of a crescent-shaped rotator cuff tear involving the supraspinatus (SS) and infraspinatus (IS) tendons. (B) Crescent-shaped tears have good medial to lateral mobility and can be repaired to bone with minimal tension. Reproduced with permission from Burkhart et al.8

at the repair site. Alternatively, if the tear is small, there may be inadequate room along the greater tuberosity for placement of multiple suture anchors, and the surgeon may decide to perform a single-row repair. In single-row repairs, sutures are placed in the torn tendon edge and secured to suture anchors along the greater tuberosity. Double-row suture anchor repairs can be performed assuming that there is enough lateral excursion of the tendons to allow this. In double-row technique, a medial row of anchors is placed adjacent to the articular margin and passed through the tendon just lateral to the musculotendinous junction. Then, a lateral row of sutures is placed to secure the lateral tendon edge. The biomechanical effects of single-row and double-row suture anchor repairs have been studied. In cadaveric studies, double-row repairs have smaller gap formation and higher loads to failure than single-row repairs.9,10 Studies

have shown that when the repair construct fails biomechanically, the suture pulls out of the tendon.11-13 Therefore, the weakest link in the repair construct is the suture-tendon interface. Increasing the number of fixation points of suture to tendon decreases the load across each suture. Double-loaded and triple-loaded suture anchors are available for this reason.

Biomechanical Studies Different suture configurations have been studied. Ma et al11 evaluated the 4 following techniques in a cadaveric model with a full-thickness SS tear. In the 2-simple technique, a double-loaded laterally based suture anchor is tied in a simple fashion. In the arthroscopic Mason–Allen technique, a horizontal mattress stitch attached to a laterally based double-loaded suture anchor, followed by a simple knot using

Figure 3 (A) Superior view of a U-shaped rotator cuff tear involving the supraspinatus (SS) and infraspinatus (IS) tendons. U-shaped tears extend much more medially, with the apex of the tear near the glenoid rim. (B) The first step in repair is done with side-to-side sutures using margin convergence sutures. (C) The free margin is then repaired to bone in a tension-free manner. Reproduced with permission from Burkhart et al.8

Traditional anchor techniques for cuff repair

217

Figure 4 (A) Superior view of a L-shaped rotator cuff tear involving the supraspinatus (SS) and rotator interval (RI). L-shaped tears are similar to U-shaped tears, except that one of the leaves is more mobile that the other, and there is a longitudinal split in the tendon tissue. (B) The technique of margin convergence is used to repair the longitudinal split. (C) The converged margin is then repaired to bone. CHL, coracohumeral ligament; IS, infraspinatus; Sub, subscapularis. Reproduced with permission from Burkhart et al.8

the other suture associated with that suture anchor. In the massive cuff technique, a free horizontal knot (not associated with an anchor) is tied within the tendon, followed by 2 horizontal mattress sutures (with both traveling medially over the horizontal mattress stitch), which are associated with a laterally based suture anchor. In the double-row technique, the medial row consisted of a horizontal mattress stitch associated with the medial suture anchor, and the lateral row consisted of a double-loaded laterally based suture anchor with both sutures tied in a simple fashion. The ultimate load to failure was higher for the double-row technique than for the other 3 techniques. The double-row technique also had lower displacement at higher load cycles. The massive cuff technique was stronger than the arthroscopic Mason–Allen and 2 simple techniques. The study recommended using the arthroscopic Mason–Allen or massive cuff technique whenever possible (Fig. 5). Mazzocca et al12 evaluated 4 suture anchor configurations in a cadaveric model with a full-thickness SS tear. The singlerow repair used 3 laterally based double-loaded anchors with

sutures tied in a simple fashion. The diamond repair consisted of 2 pairs of simple sutures, each associated with 2 laterally based double-loaded anchors, and 2 pairs of horizontal sutures, each associated with 2 medially based anchors. The mattress double-anchor repair consisted of 2 medial and 2 lateral suture anchors; suture material was shuttled from the anteromedial to the anterolateral anchor and tied over the tendon, and the same was done for the 2 posterior anchors. The modified mattress double-anchor repair differed from the mattress double-anchor repair in that a second suture was tied in a horizontal mattress configuration along each of the medial anchors (in an arthroscopic Mason–Allen configuration). The 3 double-row techniques were found to restore the SS footprint better than the single-row technique. However, there was no difference in load to failure or displacement among the 4 groups. Park et al14 studied the rotator cuff footprint contact characteristics for a transosseous-equivalent rotator cuff repair technique and compared that with a standard double-row technique. To perform a transosseous-equivalent rotator cuff

Figure 5 Schematic diagrams of the 4-stitch configurations in this study. (A) The 2-simple repair: 2 simple stitches through 1 anchor. (B) The arthroscopic Mason–Allen repair: a horizontal mattress and simple stitch through the same suture anchor. (C) The massive cuff repair: a horizontal loop tied separately to act as a checkrein loop and 2 simple stitches through 1 anchor passed medial to the horizontal loop. (D) Double-row fixation: 2 simple stitches through a laterally based suture anchor and 1 horizontal mattress stitch through a medially based suture anchor. Reproduced with permission from Ma et al.11

E.V. Cheung and M.R. Safran

218 repair, a suture limb from each of 2 medial anchors is bridged over the tendon and fixed laterally with 2 knotless anchors (4 suture bridges). Pressure-sensitive film was placed at the tendon-footprint interface. The mean pressurized contact area between the tendon and insertion was significantly greater for the 4-suture-bridge technique (124 mm2) compared with both the double-row (63 mm2) and 2-suture-bridge (100 mm2) techniques. The mean interface pressure over the tendon footprint was also greater for the 4-suture-bridge technique than for the double-row technique. The authors suggest that a transosseous-equivalent technique may help optimize the biological healing of rotator cuff repairs (Fig. 1D). Transosseous-equivalent repair will be discussed in further detail in the following chapter.

Clinical Studies Clinical studies to date have not been able to document improved outcomes using double-row repair constructs. Clinical outcomes and healing rates have been shown to be favorable with both techniques. Franceschi et al15 performed a randomized controlled study comparing arthroscopic singlerow versus double-row repair. There were 60 patients with unretracted mobile full-thickness rotator cuff tears with 2-year follow-up. A medial mattress suture configuration and lateral simple suture technique were used in the double-row group (Fig. 6). University of California, Los Angeles (UCLA) shoulder score was 11.5 preop to 32.9 postop in the single row group versus 10.1 preop to 33.3 postop in the doublerow group. No significant differences were found in clinical outcomes, range or motion, or structural rates of healing on magnetic resonance angiography between the 2 groups. Burks et al16 performed a prospective randomized clinical trial comparing arthroscopic single-row and double-row repairs. There were 40 patients in this study with 1-year followup. Clinical outcomes, motion, strength, and magnetic resonance imaging healing measurements were similar in both groups. Retear was noted on magnetic resonance imaging in 2 patients in each group. In a larger study, Grasso et al17 randomized 80 patients to either single-row or double-row repair. Their results were

Figure 7 Transosseous-equivalent rotator cuff repair configuration. Reproduced with permission from Park et al.14

similar to the aforementioned clinical studies at 2-year follow-up, with no significant difference in clinical outcomes (disabilities of the arm, shoulder and hand [DASH] and Constant scores) or in strength testing between the double-row and single-row groups. Suture-bridge constructs use a medial row of anchors with sutures passing through the rotator cuff in a mattress configuration. The suture tails from the medial row are then passed through a lateral row of knotless anchors, which provide an additional surface area of compression over the footprint. Kim et al18 published a cohort study of 52 patients who underwent either a traditional double-row repair or a suture-bridge repair, with 2-year follow-up (Fig. 7). There was no significant difference in clinical outcomes or healing rates between the 2 repair techniques. Frank et al19 reported on the clinical results of the transosseous-equivalent suture-bridge technique. Overall, healing was 88% at a minimum 1-year follow-up. The data published thus far support predictable healing and overall favorable results with both single-row and double-row repairs using modern suture anchor devices.

Conclusions In conclusion, arthroscopic rotator cuff repair techniques have continued to evolve for the past few years. Achieving a biomechanically strong construct is important for biological healing. There have been no clinical studies showing advantage of 1 anchor type over another, as the main mode of failure of arthroscopic rotator cuff repair remains suture pullout from the tendon. Newer technological advances will enable the surgeon to perform these repairs with greater ease and may potentially further improve clinical outcomes.

References

Figure 6 Double-row rotator cuff repair configuration. Reproduced with permission from Park et al.14

1. Milgrom C, Schaffler M, Gilbert S, et al: Rotator-cuff changes in asymptomatic adults. The effect of age, hand dominance and gender. J Bone Joint Surg Br 77:296-298, 1995 2. Sher JS, Uribe JW, Posada A, et al: Abnormal findings on magnetic resonance images of asymptomatic shoulders. J Bone Joint Surg Am 77:10-15, 1995

Traditional anchor techniques for cuff repair 3. Oh LS, Wolf BR, Hall MP, et al: Indications for rotator cuff repair: A systematic review. Clin Orthop Relat Res 455:52-63, 2007 4. Yamaguchi K, Ditsios K, Middleton WD, et al: The demographic and morphological features of rotator cuff disease. A comparison of asymptomatic and symptomatic shoulders. J Bone Joint Surg Am 88:16991704, 2006 5. Mochizuki T, Sugaya H, Uomizu M, et al: Humeral insertion of the supraspinatus and infraspinatus. New anatomical findings regarding the footprint of the rotator cuff. J Bone Joint Surg Am 90:962969, 2008 6. Clark JM, Harryman DT: Tendons, ligaments, and capsule of the rotator cuff. Gross and microscopic anatomy. J Bone Joint Surg Am 74:713725, 1992 7. Galatz LM, Sandell LJ, Rothermich SY, et al: Characteristics of the rat supraspinatus tendon during tendon-to-bone healing after acute injury. J Orthop Res 24:541-550, 2006 8. Burkhart SS, Lo IK: Arthroscopic rotator cuff repair. J Am Acad Orthop Surg 14:333-346, 2006 9. Nho SJ, Slabaugh MA, Seroyer ST, et al: Does the literature support double-row suture anchor fixation for arthroscopic rotator cuff repair? A systematic review comparing double-row and single-row suture anchor configuration. Arthroscopy 25:1319-1328, 2009 10. Park MC, Cadet ER, Levine WN, et al: Tendon-to-bone pressure distributions at a repaired rotator cuff footprint using transosseous suture and suture anchor fixation techniques. Am J Sports Med 33:11541159, 2005 11. Ma CB, Comerford L, Wilson J, et al: Biomechanical evaluation of

219

12.

13.

14.

15.

16.

17.

18.

19.

arthroscopic rotator cuff repairs: Double-row compared with single-row fixation. J Bone Joint Surg Am 88:403-410, 2006 Mazzocca AD, Millett PJ, Guanche CA, et al: Arthroscopic single-row versus double-row suture anchor rotator cuff repair. Am J Sports Med 33:1861-1868, 2005 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 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 Franceschi F, Ruzzini L, Longo UG, et al: Equivalent clinical results of arthroscopic single-row and double-row suture anchor repair for rotator cuff tears: A randomized controlled trial. Am J Sports Med 35:12541260, 2007 Burks RT, Crim J, Brown N, et al: A prospective randomized clinical trial comparing arthroscopic single- and double-row rotator cuff repair: Magnetic resonance imaging and early clinical evaluation. Am J Sports Med 37:674-682, 2009 Grasso A, Milano G, Salvatore M, et al: Single-row versus double-row arthroscopic rotator cuff repair: A prospective randomized clinical study. Arthroscopy 25:4-12, 2009 Kim KC, Shin HD, Lee WY, et al: Repair integrity and functional outcome after arthroscopic rotator cuff repair: Double-row versus suturebridge technique. Am J Sports Med 40:294-299, 2012 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