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The interval slide in continuity: a method of mobilizing the anterosuperior rotator cuff without disrupting the tear margins
Technical Note
The Interval Slide in Continuity: A Method of Mobilizing the Anterosuperior Rotator Cuff Without Disrupting the Tear Margins Ian K. Y. Lo, M.D., F.R.C.S.C., and Stephen S. Burkhart, M.D.
Abstract: Massive, contracted, immobile rotator cuff tears involving the subscapularis, supraspinatus, and infraspinatus tendons present difficult surgical challenges to the arthroscopic surgeon. We describe the interval slide in continuity, a release and resection of a portion of the coracohumeral ligament and rotator interval. This technique improves the mobility of the subscapularis and supraspinatus tendons but also maintains an important lateral bridge of tissue spanning the interval between the subscapularis anteriorly and the supraspinatus tendon superiorly. After repair of the subscapularis tendon, this lateral rotator interval tissue can greatly facilitate repair of the posterosuperior rotator cuff. Key Words: Interval slide in continuity—Coracohumeral ligament—Rotator interval—Rotator cuff tear.
M
assive, contracted, immobile rotator cuff tears are rare lesions, and in our experience, represent less than 10% of massive rotator cuff tears.1 Repairing these tears arthroscopically is significantly challenging and usually requires advanced techniques for repair. Several arthroscopic methods, including the interval slide,1,2 have been described to improve the mobility of such tears. In this technique, described by Tauro2 and Lo and Burkhart,1 the tissue between the rotator interval and supraspinatus tendon is incised. This can significantly improve the mobility of the supraspinatus tendon, allowing repair of seemingly irreparable tears. However, in complex cases involving tears of the
From The San Antonio Orthopaedic Group (I.K.Y.L., S.S.B.), and the Department of Orthopaedic Surgery, University of Texas Health Science Center at San Antonio (S.S.B.), San Antonio, Texas, U.S.A. Address correspondence and reprint requests to Stephen S. Burkhart, M.D., 540 Madison Oak Dr, Suite 620, San Antonio, TX 78258, U.S.A. E-mail: [email protected] © 2004 by the Arthroscopy Association of North America 0749-8063/04/2004-3672$30.00/0 doi:10.1016/j.arthro.2004.01.016
supraspinatus tendon and the subscapularis tendon, an interval slide will create 2 separate flaps of tissue: an anterior flap consisting of the subscapularis and rotator interval and a posterior flap consisting of the supraspinatus, infraspinatus, and teres minor tendons. Although repair of these 2 flaps of tissue is technically possible, it is difficult because of the “floppy” nature of the tissue flaps. This article describes the interval slide in continuity, a release and resection of a portion of the coracohumeral ligament and rotator interval performed while maintaining the lateral margin of the rotator interval (Fig 1). This technique improves the mobility of both the subscapularis and supraspinatus tendons and does not create 2 separate flaps of tissue, allowing a simplified repair of the posterosuperior rotator cuff. SURGICAL TECHNIQUE After induction of general anesthesia, the patient is placed in the lateral decubitis position. The patient is appropriately bolstered and padded, and a warming blanket is applied to prevent hypothermia. Five to 10 lb of balanced suspension are used with the arm in 20°
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 20, No 4 (April), 2004: pp 435-441
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FIGURE 2. Arthroscopic view of a left shoulder from a posterior viewing portal using a 70° arthroscope shows the torn subscapularis tendon with attached comma sign. In the background are the coracoid tip with attached coracoacromial ligament and conjoint tendon. Note the decrease in the coracohumeral space. (H, humerus; CT, coracoid tip; CAL, coracoacromial ligament; CJ, conjoint tendon; SSc, subscapularis tendon; asterisk, comma sign.) Note that all arthroscopic views are of a left shoulder oriented in the beach chair position with the patient’s head toward the top of the figure.
to 30° of abduction and 20° of forward flexion (Star Sleeve Traction System; Arthrex, Naples, FL). Diagnostic glenohumeral arthroscopy is performed through a standard posterior portal with an arthroscopic pump maintaining pressure at 60 mm Hg. In cases of large and massive anterosuperior rotator cuff tears, diagnostic glenohumeral arthroscopy will reveal a torn subscapularis tendon and torn posterosuperior rotator cuff. In cases involving chronic retracted adhesed subscapularis tears, identifying the superior and lateral borders of the subscapularis tendon can be difficult. We have previously described the “comma sign,” which can aid in identifying the margin of the torn subscapularis tendon (Fig 2).3 The
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comma sign is an arc formed by the conjoined medial coracohumeral ligament and superior glenohumeral ligament. These avulse with the subscapularis tendon from the humerus, where their combined footprint is located adjacent and directly superior to the subscapularis footprint. The comma sign is therefore a useful marker of the superolateral corner of the torn subscapularis tendon. In cases of combined subscapularis, supraspinatus, and infraspinatus tendon tears, subcoracoid impingement is a common associated finding. Thus, careful evaluation of the coracohumeral space is performed.4,5 To help identify the coracoid, a shaver is introduced through a lateral portal, and the coracoid tip is identified by palpating a bony prominence in the anterior soft tissue structures (Fig 2). In addition, the coracoacromial ligament can be followed from its superior (acromial) origin to its attachment inferiorly onto the coracoid. The coracohumeral space can then be directly measured using the shaver diameter as a reference. If subcoracoid impingement is present and symptomatic, an arthroscopic coracoplasty is performed as previously described (Fig 3).4,5 Massive, contracted, immobile rotator cuff tears will, by definition, show minimal mobility from a medial to lateral direction of both the subscapularis tendon and the posterosuperior rotator cuff. To improve the mobility of these tears, an interval slide in continuity can be performed. The surgeon begins by skeletonizing the posterolateral coracoid to safely reach the lateral base of the coracoid from which the coracohumeral ligament is released. After the coracoplasty, the posterolateral coracoid neck must be exposed. Viewing through a lateral portal, the surgeon introduces a shaver or cautery probe through an accessory lateral portal and excises the soft tissue overlying the posterolateral aspect of the coracoid tip and coracoid neck (Fig 4). This soft tissue ablation is continued to the lateral aspect of the base of the coracoid, which results in the excision of the origin of the coracohumeral ligament. Care is taken to avoid
4™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™ FIGURE 1. Schematic representation of the interval slide in continuity. Anterior view of a left shoulder. (A) An anterosuperior rotator cuff tear involving 50% of the subscapularis tendon and a massive tear of the supraspinatus and infraspinatus tendons. (B) A coracoplasty is performed resecting the posterolateral aspect of the coracoid tip. The dotted box outlines the proposed area for the window of the interval slide in continuity. (C) An interval slide in continuity is performed by first exposing the posterolateral aspect of the base of the coracoid. This releases the coracohumeral ligament. Then the medial rotator interval tissue is excised, creating a “window” through the rotator interval, further releasing and excising the coracohumeral ligament. Care is taken to ensure the lateral margin of the rotator interval remains intact, maintaining the continuity between the subscapularis tendon and the supraspinatus tendon. (D) After an interval slide in continuity, improved mobility of the subscapularis tendon is seen. The subscapularis tear can now be repaired to bone, leaving a U-shaped posterosuperior rotator cuff tear to be repaired. (E) The residual U-shaped posterosuperior rotator cuff tear is repaired with side-to-side sutures using the principle of margin convergence. (F) The converged margin is then repaired to bone in a tension-free manner. CHL, coracohumeral ligament.
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FIGURE 3. Arthroscopic “aerial” view from a posterior portal using a 70° arthroscope, showing an increase in the coracohumeral space after coracoplasty. A traction suture has been placed through the subscapularis tendon. (CT, coracoid tip; H, humerus; SSc, subscapularis tendon; asterisk, comma sign.)
FIGURE 4. Coracohumeral ligament release and coracoid dissection. Arthroscopic view from a lateral portal. A shaver has been introduced through an accessory lateral portal and is used, in conjunction with electrocautery and arthroscopic elevators, to dissect and expose the coracoid neck, releasing and excising the origin of coracohumeral ligament from the lateral aspect of the coracoid. (CT, coracoid tip; CN, coracoid neck; asterisk, comma sign.)
FIGURE 5. Rotator interval resection and release. Arthroscopic view from a lateral portal. While lateral traction is being applied to the subscapularis, a shaver has been introduced through an accessory lateral portal. A “window” has been created by excising the medial rotator interval while preserving an intact lateral bridge of rotator interval tissue containing the comma sign. In this photograph, the coracoid base can be seen through the window in the rotator interval. Care is taken to completely release and excise the coracohumeral ligament from the lateral aspect of the base of the coracoid. (SSc, subscapularis tendon; CB, coracoid base; G, glenoid; asterisk, comma sign.)
dissection inferior and medial to the coracoid, which would place the neurovascular structures at risk. At this point, the release of the soft tissues from the lateral base of the coracoid has created a partial coracohumeral ligament release, which allows greater lateral excursion of the subscapularis. This increased excursion can be shown by applying lateral tension to the traction sutures. Lateral pull on the traction sutures will bring the rotator interval tissue into view. This rotator interval tissue has been medially retracted on a chronic basis because of the contracted coracohumeral ligament. At this point, a shaver or cautery probe is directed to the posterior aspect of the rotator interval and a “window” is created through the rotator interval by resecting the medial portion of the interval tissue until the lateral aspect of the base of the coracoid is identified through this defect (Fig 5). The excised tissue includes the coracohumeral ligament attachment to the coracoid. Care is taken to ensure that the lateral aspect of the rotator interval is preserved, maintaining the continuity of the subscapularis tendon to the supraspinatus
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tendon (Fig 6). This tissue essentially consists of the lateral rotator interval and the comma sign (the medial coracohumeral ligament and superior glenohumeral ligament). After an interval slide in continuity, the mobility of the subscapularis tendon will be improved. This increased mobility allows repair of the torn subscapularis to a bone bed in a tension-free manner as previously described (Fig 7).6,7 By maintaining the lateral aspect of the rotator interval and comma sign, this tissue can now be incorporated during repair of the posterosuperior rotator cuff (Fig 8). This tissue is essential when repairing U-shaped or L-shaped rotator cuff tears, which require side-to-side sutures for “margin convergence” (Fig 9).8-12 Incising or excising this tissue during a standard interval slide would preclude placement of side-to-side sutures, making repair much more difficult. FIGURE 6. Completed interval slide in continuity. Arthroscopic view from a posterior portal shows a completed interval slide in continuity. Note that a lateral bridge of rotator interval tissue has been maintained which contains the comma sign and leads to the superolateral aspect of the torn subscapularis tendon. The coracoid tip and coracoid base are visible on either side of the comma sign. (CT, coracoid tip; CB, coracoid base; SSc, subscapularis tendon; H, humerus; G, glenoid; asterisk, comma sign.)
DISCUSSION Arthroscopic repair of massive, contracted, immobile rotator cuff tears involving the subscapularis, supraspinatus, and infraspinatus tendons present difficult challenges to the arthroscopic surgeon. In these cases, because of the propensity of the coracohumeral ligament to rigidly shorten and thereby tether the rotator cuff medially, mobilization techniques are re-
FIGURE 7. Arthroscopic views show a completed subscapularis repair. (A) Posterior portal using a 70° arthroscope showing “aerial” view of repair. (B) Posterior portal using a 30° arthroscope showing the intra-articular perspective. Note that the comma sign is still intact. The hooked probe shows the interval slide in continuity. (H, humerus; SSc, subscapularis; asterisk, comma sign.)
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quired for the subscapularis tendon to allow repair of the entire rotator cuff to a lateral bone bed in a tension-free manner. The interval slide in continuity is a useful technique in these complex cases and improves the mobility of the subscapularis and posterosuperior rotator cuff without creating 2 separate flaps of tissue. In the senior author’s (S.S.B.) experience of treating these complex tears with a standard interval slide (without maintaining a lateral margin of rotator interval tissue), repairing the posterosuperior rotator cuff can be difficult because the tissue flap becomes floppy and difficult to control after the release is performed. This makes simple procedures such as suture passage awkward and time consuming. Because the coracohumeral ligament originates from the lateral aspect of the base of the coracoid,13-15 one can understand that by excising and exposing the tissue overlying the lateral aspect of the coracoid base and neck, the coracohumeral ligament is completely released during an interval slide in continuity. This release improves the mobility of both the subscapularis and posterosuperior rotator cuff because the coracohumeral ligament attaches to and envelopes these structures distally.13-15 As has been shown in open and
FIGURE 9. Arthroscopic view through a lateral portal after rotator cuff repair. The intact lateral portion of the rotator interval including the tissue of the comma sign, has been incorporated into the side-to-side sutures (arrows) used during repair of this U-shaped rotator cuff tear.
arthroscopic rotator cuff repairs, incising the coracohumeral ligament can significantly improve tendon mobility.16-19 Furthermore, during an interval slide in continuity, a portion of the rotator interval is excised, thus producing a partial interval release. We have found that this can further improve the mobility of both the subscapularis and supraspinatus tendons as effectively as a complete interval slide.1,2 When performing this technique, care must be taken to avoid dissection inferior and medial to the coracoid base, which can place the neurovascular structures at risk. CONCLUSIONS
FIGURE 8. Arthroscopic view through a lateral portal showing a residual U-shaped posterosuperior rotator cuff defect which can be closed by margin convergence principles. The intact lateral portion of the rotator interval serves as the anterior leaf and can be repaired to the posterior leaf of the rotator cuff. A hooked probe has been placed within the defect created by the interval slide in continuity. (H, humeral head; asterisk, comma sign; SSc, subscapularis.)
The interval slide in continuity is a useful technique during repair of massive, contracted, immobile rotator cuff tears involving the subscapularis, supraspinatus, and infraspinatus tendons. This technique combines a release of the coracohumeral ligament and resection of a portion of the rotator interval, improving the mobility of the subscapularis and posterosuperior rotator cuff while maintaining continuity. REFERENCES 1. Lo IK, Burkhart SS. Arthroscopic repair of massive, contracted immobile rotator cuff tears using single and double
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2. 3. 4. 5.
6. 7. 8. 9.
interval slides: Technique and preliminary results. Arthroscopy 2004;20:22-33. Tauro JC. Arthroscopic “interval slide” in the repair of large rotator cuff tears. Arthroscopy 1999;15:527-530. Lo IK, Burkhart SS. The comma sign: An arthroscopic guide to the torn subscapularis tendon. Arthroscopy 2003;19:334337. Lo IK, Burkhart SS. Arthroscopic coracoplasty through the rotator interval. Arthroscopy 2003;19:667-671. Lo IK, Parten PM, Burkhart SS. Combined subcoracoid and subacromial impingement in association with anterosuperior rotator cuff tears: An arthroscopic approach. Arthroscopy 2003;19:1068-1078. Burkhart SS, Tehrany AM. Arthroscopic subscapularis repair: Technique and preliminary results. Arthroscopy 2002;18:454463. Lo IK, Burkhart SS. Subscapularis tears: Arthroscopic repair of the forgotten rotator cuff tendon. Tech Shoulder Elbow Surg 2002;3:282-291. Burkhart SS. Arthroscopic repair of massive rotator cuff tears: Concept of margin convergence. Tech Shoulder Elbow Surg 2000;1:232-239. Burkhart SS. A stepwise approach to arthroscopic rotator cuff repair based on biomechanical principles. Arthroscopy 2000; 16:82-90.
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10. Burkhart SS. Arthroscopic rotator cuff repair: Indications and techniques. Oper Tech Sports Med 1997;5:204-214. 11. Burkhart SS, Athanasiou KA, Wirth MA. Margin convergence: A method of reducing strain in massive rotator cuff tears. Arthroscopy 1996;12:335-338. 12. Burkhart SS. Arthroscopic treatment of massive rotator cuff tears. Clin Orthop 2001;390:107-118. 13. Clark JM, Harryman DT. Tendon, ligaments and capsule of the rotator cuff. J Bone Joint Surg Am 1992;74:713-725. 14. Jost B, Koch PP, Gerber C. Anatomy and functional aspects of the rotator interval. J Shoulder Elbow Surg 2000;9:336-341. 15. Kolts I, Busch LC, Tomusk H, et al. Macroscopical anatomy of the so-called “rotator interval”: A cadaver study on 19 shoulder joints. Ann Anat 2002;184:9-14. 16. Neer CS II. Cuff tears, biceps lesions, and impingement. In: Neer CS II, ed. Shoulder reconstruction. Philadelphia: WB Saunders, 1990;41-142. 17. Neer CS II, Satterlee CC, Dalsey RM, Flatow EL. On the value of the coracohumeral ligament release. Orthop Trans 1989;13: 234-236. 18. Tauro JC. Arthroscopic rotator cuff repair: Analysis of technique and results at 2- and 3-year follow-up. Arthroscopy 1998;14:45-51. 19. Gartsman GM, Khan M, Hammerman SM. Arthroscopic repair of full-thickness tears of the rotator cuff. J Bone Joint Surg Am 1998;80:832-840.
The Interval Slide in Continuity: A Method of Mobilizing the Anterosuperior Rotator Cuff Without Disrupting the Tear Margins Ian K. Y. Lo, M.D., F.R.C.S.C., and Stephen S. Burkhart, M.D.
Abstract: Massive, contracted, immobile rotator cuff tears involving the subscapularis, supraspinatus, and infraspinatus tendons present difficult surgical challenges to the arthroscopic surgeon. We describe the interval slide in continuity, a release and resection of a portion of the coracohumeral ligament and rotator interval. This technique improves the mobility of the subscapularis and supraspinatus tendons but also maintains an important lateral bridge of tissue spanning the interval between the subscapularis anteriorly and the supraspinatus tendon superiorly. After repair of the subscapularis tendon, this lateral rotator interval tissue can greatly facilitate repair of the posterosuperior rotator cuff. Key Words: Interval slide in continuity—Coracohumeral ligament—Rotator interval—Rotator cuff tear.
M
assive, contracted, immobile rotator cuff tears are rare lesions, and in our experience, represent less than 10% of massive rotator cuff tears.1 Repairing these tears arthroscopically is significantly challenging and usually requires advanced techniques for repair. Several arthroscopic methods, including the interval slide,1,2 have been described to improve the mobility of such tears. In this technique, described by Tauro2 and Lo and Burkhart,1 the tissue between the rotator interval and supraspinatus tendon is incised. This can significantly improve the mobility of the supraspinatus tendon, allowing repair of seemingly irreparable tears. However, in complex cases involving tears of the
From The San Antonio Orthopaedic Group (I.K.Y.L., S.S.B.), and the Department of Orthopaedic Surgery, University of Texas Health Science Center at San Antonio (S.S.B.), San Antonio, Texas, U.S.A. Address correspondence and reprint requests to Stephen S. Burkhart, M.D., 540 Madison Oak Dr, Suite 620, San Antonio, TX 78258, U.S.A. E-mail: [email protected] © 2004 by the Arthroscopy Association of North America 0749-8063/04/2004-3672$30.00/0 doi:10.1016/j.arthro.2004.01.016
supraspinatus tendon and the subscapularis tendon, an interval slide will create 2 separate flaps of tissue: an anterior flap consisting of the subscapularis and rotator interval and a posterior flap consisting of the supraspinatus, infraspinatus, and teres minor tendons. Although repair of these 2 flaps of tissue is technically possible, it is difficult because of the “floppy” nature of the tissue flaps. This article describes the interval slide in continuity, a release and resection of a portion of the coracohumeral ligament and rotator interval performed while maintaining the lateral margin of the rotator interval (Fig 1). This technique improves the mobility of both the subscapularis and supraspinatus tendons and does not create 2 separate flaps of tissue, allowing a simplified repair of the posterosuperior rotator cuff. SURGICAL TECHNIQUE After induction of general anesthesia, the patient is placed in the lateral decubitis position. The patient is appropriately bolstered and padded, and a warming blanket is applied to prevent hypothermia. Five to 10 lb of balanced suspension are used with the arm in 20°
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 20, No 4 (April), 2004: pp 435-441
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FIGURE 2. Arthroscopic view of a left shoulder from a posterior viewing portal using a 70° arthroscope shows the torn subscapularis tendon with attached comma sign. In the background are the coracoid tip with attached coracoacromial ligament and conjoint tendon. Note the decrease in the coracohumeral space. (H, humerus; CT, coracoid tip; CAL, coracoacromial ligament; CJ, conjoint tendon; SSc, subscapularis tendon; asterisk, comma sign.) Note that all arthroscopic views are of a left shoulder oriented in the beach chair position with the patient’s head toward the top of the figure.
to 30° of abduction and 20° of forward flexion (Star Sleeve Traction System; Arthrex, Naples, FL). Diagnostic glenohumeral arthroscopy is performed through a standard posterior portal with an arthroscopic pump maintaining pressure at 60 mm Hg. In cases of large and massive anterosuperior rotator cuff tears, diagnostic glenohumeral arthroscopy will reveal a torn subscapularis tendon and torn posterosuperior rotator cuff. In cases involving chronic retracted adhesed subscapularis tears, identifying the superior and lateral borders of the subscapularis tendon can be difficult. We have previously described the “comma sign,” which can aid in identifying the margin of the torn subscapularis tendon (Fig 2).3 The
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comma sign is an arc formed by the conjoined medial coracohumeral ligament and superior glenohumeral ligament. These avulse with the subscapularis tendon from the humerus, where their combined footprint is located adjacent and directly superior to the subscapularis footprint. The comma sign is therefore a useful marker of the superolateral corner of the torn subscapularis tendon. In cases of combined subscapularis, supraspinatus, and infraspinatus tendon tears, subcoracoid impingement is a common associated finding. Thus, careful evaluation of the coracohumeral space is performed.4,5 To help identify the coracoid, a shaver is introduced through a lateral portal, and the coracoid tip is identified by palpating a bony prominence in the anterior soft tissue structures (Fig 2). In addition, the coracoacromial ligament can be followed from its superior (acromial) origin to its attachment inferiorly onto the coracoid. The coracohumeral space can then be directly measured using the shaver diameter as a reference. If subcoracoid impingement is present and symptomatic, an arthroscopic coracoplasty is performed as previously described (Fig 3).4,5 Massive, contracted, immobile rotator cuff tears will, by definition, show minimal mobility from a medial to lateral direction of both the subscapularis tendon and the posterosuperior rotator cuff. To improve the mobility of these tears, an interval slide in continuity can be performed. The surgeon begins by skeletonizing the posterolateral coracoid to safely reach the lateral base of the coracoid from which the coracohumeral ligament is released. After the coracoplasty, the posterolateral coracoid neck must be exposed. Viewing through a lateral portal, the surgeon introduces a shaver or cautery probe through an accessory lateral portal and excises the soft tissue overlying the posterolateral aspect of the coracoid tip and coracoid neck (Fig 4). This soft tissue ablation is continued to the lateral aspect of the base of the coracoid, which results in the excision of the origin of the coracohumeral ligament. Care is taken to avoid
4™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™™ FIGURE 1. Schematic representation of the interval slide in continuity. Anterior view of a left shoulder. (A) An anterosuperior rotator cuff tear involving 50% of the subscapularis tendon and a massive tear of the supraspinatus and infraspinatus tendons. (B) A coracoplasty is performed resecting the posterolateral aspect of the coracoid tip. The dotted box outlines the proposed area for the window of the interval slide in continuity. (C) An interval slide in continuity is performed by first exposing the posterolateral aspect of the base of the coracoid. This releases the coracohumeral ligament. Then the medial rotator interval tissue is excised, creating a “window” through the rotator interval, further releasing and excising the coracohumeral ligament. Care is taken to ensure the lateral margin of the rotator interval remains intact, maintaining the continuity between the subscapularis tendon and the supraspinatus tendon. (D) After an interval slide in continuity, improved mobility of the subscapularis tendon is seen. The subscapularis tear can now be repaired to bone, leaving a U-shaped posterosuperior rotator cuff tear to be repaired. (E) The residual U-shaped posterosuperior rotator cuff tear is repaired with side-to-side sutures using the principle of margin convergence. (F) The converged margin is then repaired to bone in a tension-free manner. CHL, coracohumeral ligament.
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FIGURE 3. Arthroscopic “aerial” view from a posterior portal using a 70° arthroscope, showing an increase in the coracohumeral space after coracoplasty. A traction suture has been placed through the subscapularis tendon. (CT, coracoid tip; H, humerus; SSc, subscapularis tendon; asterisk, comma sign.)
FIGURE 4. Coracohumeral ligament release and coracoid dissection. Arthroscopic view from a lateral portal. A shaver has been introduced through an accessory lateral portal and is used, in conjunction with electrocautery and arthroscopic elevators, to dissect and expose the coracoid neck, releasing and excising the origin of coracohumeral ligament from the lateral aspect of the coracoid. (CT, coracoid tip; CN, coracoid neck; asterisk, comma sign.)
FIGURE 5. Rotator interval resection and release. Arthroscopic view from a lateral portal. While lateral traction is being applied to the subscapularis, a shaver has been introduced through an accessory lateral portal. A “window” has been created by excising the medial rotator interval while preserving an intact lateral bridge of rotator interval tissue containing the comma sign. In this photograph, the coracoid base can be seen through the window in the rotator interval. Care is taken to completely release and excise the coracohumeral ligament from the lateral aspect of the base of the coracoid. (SSc, subscapularis tendon; CB, coracoid base; G, glenoid; asterisk, comma sign.)
dissection inferior and medial to the coracoid, which would place the neurovascular structures at risk. At this point, the release of the soft tissues from the lateral base of the coracoid has created a partial coracohumeral ligament release, which allows greater lateral excursion of the subscapularis. This increased excursion can be shown by applying lateral tension to the traction sutures. Lateral pull on the traction sutures will bring the rotator interval tissue into view. This rotator interval tissue has been medially retracted on a chronic basis because of the contracted coracohumeral ligament. At this point, a shaver or cautery probe is directed to the posterior aspect of the rotator interval and a “window” is created through the rotator interval by resecting the medial portion of the interval tissue until the lateral aspect of the base of the coracoid is identified through this defect (Fig 5). The excised tissue includes the coracohumeral ligament attachment to the coracoid. Care is taken to ensure that the lateral aspect of the rotator interval is preserved, maintaining the continuity of the subscapularis tendon to the supraspinatus
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tendon (Fig 6). This tissue essentially consists of the lateral rotator interval and the comma sign (the medial coracohumeral ligament and superior glenohumeral ligament). After an interval slide in continuity, the mobility of the subscapularis tendon will be improved. This increased mobility allows repair of the torn subscapularis to a bone bed in a tension-free manner as previously described (Fig 7).6,7 By maintaining the lateral aspect of the rotator interval and comma sign, this tissue can now be incorporated during repair of the posterosuperior rotator cuff (Fig 8). This tissue is essential when repairing U-shaped or L-shaped rotator cuff tears, which require side-to-side sutures for “margin convergence” (Fig 9).8-12 Incising or excising this tissue during a standard interval slide would preclude placement of side-to-side sutures, making repair much more difficult. FIGURE 6. Completed interval slide in continuity. Arthroscopic view from a posterior portal shows a completed interval slide in continuity. Note that a lateral bridge of rotator interval tissue has been maintained which contains the comma sign and leads to the superolateral aspect of the torn subscapularis tendon. The coracoid tip and coracoid base are visible on either side of the comma sign. (CT, coracoid tip; CB, coracoid base; SSc, subscapularis tendon; H, humerus; G, glenoid; asterisk, comma sign.)
DISCUSSION Arthroscopic repair of massive, contracted, immobile rotator cuff tears involving the subscapularis, supraspinatus, and infraspinatus tendons present difficult challenges to the arthroscopic surgeon. In these cases, because of the propensity of the coracohumeral ligament to rigidly shorten and thereby tether the rotator cuff medially, mobilization techniques are re-
FIGURE 7. Arthroscopic views show a completed subscapularis repair. (A) Posterior portal using a 70° arthroscope showing “aerial” view of repair. (B) Posterior portal using a 30° arthroscope showing the intra-articular perspective. Note that the comma sign is still intact. The hooked probe shows the interval slide in continuity. (H, humerus; SSc, subscapularis; asterisk, comma sign.)
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quired for the subscapularis tendon to allow repair of the entire rotator cuff to a lateral bone bed in a tension-free manner. The interval slide in continuity is a useful technique in these complex cases and improves the mobility of the subscapularis and posterosuperior rotator cuff without creating 2 separate flaps of tissue. In the senior author’s (S.S.B.) experience of treating these complex tears with a standard interval slide (without maintaining a lateral margin of rotator interval tissue), repairing the posterosuperior rotator cuff can be difficult because the tissue flap becomes floppy and difficult to control after the release is performed. This makes simple procedures such as suture passage awkward and time consuming. Because the coracohumeral ligament originates from the lateral aspect of the base of the coracoid,13-15 one can understand that by excising and exposing the tissue overlying the lateral aspect of the coracoid base and neck, the coracohumeral ligament is completely released during an interval slide in continuity. This release improves the mobility of both the subscapularis and posterosuperior rotator cuff because the coracohumeral ligament attaches to and envelopes these structures distally.13-15 As has been shown in open and
FIGURE 9. Arthroscopic view through a lateral portal after rotator cuff repair. The intact lateral portion of the rotator interval including the tissue of the comma sign, has been incorporated into the side-to-side sutures (arrows) used during repair of this U-shaped rotator cuff tear.
arthroscopic rotator cuff repairs, incising the coracohumeral ligament can significantly improve tendon mobility.16-19 Furthermore, during an interval slide in continuity, a portion of the rotator interval is excised, thus producing a partial interval release. We have found that this can further improve the mobility of both the subscapularis and supraspinatus tendons as effectively as a complete interval slide.1,2 When performing this technique, care must be taken to avoid dissection inferior and medial to the coracoid base, which can place the neurovascular structures at risk. CONCLUSIONS
FIGURE 8. Arthroscopic view through a lateral portal showing a residual U-shaped posterosuperior rotator cuff defect which can be closed by margin convergence principles. The intact lateral portion of the rotator interval serves as the anterior leaf and can be repaired to the posterior leaf of the rotator cuff. A hooked probe has been placed within the defect created by the interval slide in continuity. (H, humeral head; asterisk, comma sign; SSc, subscapularis.)
The interval slide in continuity is a useful technique during repair of massive, contracted, immobile rotator cuff tears involving the subscapularis, supraspinatus, and infraspinatus tendons. This technique combines a release of the coracohumeral ligament and resection of a portion of the rotator interval, improving the mobility of the subscapularis and posterosuperior rotator cuff while maintaining continuity. REFERENCES 1. Lo IK, Burkhart SS. Arthroscopic repair of massive, contracted immobile rotator cuff tears using single and double
INTERVAL SLIDE IN CONTINUITY
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6. 7. 8. 9.
interval slides: Technique and preliminary results. Arthroscopy 2004;20:22-33. Tauro JC. Arthroscopic “interval slide” in the repair of large rotator cuff tears. Arthroscopy 1999;15:527-530. Lo IK, Burkhart SS. The comma sign: An arthroscopic guide to the torn subscapularis tendon. Arthroscopy 2003;19:334337. Lo IK, Burkhart SS. Arthroscopic coracoplasty through the rotator interval. Arthroscopy 2003;19:667-671. Lo IK, Parten PM, Burkhart SS. Combined subcoracoid and subacromial impingement in association with anterosuperior rotator cuff tears: An arthroscopic approach. Arthroscopy 2003;19:1068-1078. Burkhart SS, Tehrany AM. Arthroscopic subscapularis repair: Technique and preliminary results. Arthroscopy 2002;18:454463. Lo IK, Burkhart SS. Subscapularis tears: Arthroscopic repair of the forgotten rotator cuff tendon. Tech Shoulder Elbow Surg 2002;3:282-291. Burkhart SS. Arthroscopic repair of massive rotator cuff tears: Concept of margin convergence. Tech Shoulder Elbow Surg 2000;1:232-239. Burkhart SS. A stepwise approach to arthroscopic rotator cuff repair based on biomechanical principles. Arthroscopy 2000; 16:82-90.
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10. Burkhart SS. Arthroscopic rotator cuff repair: Indications and techniques. Oper Tech Sports Med 1997;5:204-214. 11. Burkhart SS, Athanasiou KA, Wirth MA. Margin convergence: A method of reducing strain in massive rotator cuff tears. Arthroscopy 1996;12:335-338. 12. Burkhart SS. Arthroscopic treatment of massive rotator cuff tears. Clin Orthop 2001;390:107-118. 13. Clark JM, Harryman DT. Tendon, ligaments and capsule of the rotator cuff. J Bone Joint Surg Am 1992;74:713-725. 14. Jost B, Koch PP, Gerber C. Anatomy and functional aspects of the rotator interval. J Shoulder Elbow Surg 2000;9:336-341. 15. Kolts I, Busch LC, Tomusk H, et al. Macroscopical anatomy of the so-called “rotator interval”: A cadaver study on 19 shoulder joints. Ann Anat 2002;184:9-14. 16. Neer CS II. Cuff tears, biceps lesions, and impingement. In: Neer CS II, ed. Shoulder reconstruction. Philadelphia: WB Saunders, 1990;41-142. 17. Neer CS II, Satterlee CC, Dalsey RM, Flatow EL. On the value of the coracohumeral ligament release. Orthop Trans 1989;13: 234-236. 18. Tauro JC. Arthroscopic rotator cuff repair: Analysis of technique and results at 2- and 3-year follow-up. Arthroscopy 1998;14:45-51. 19. Gartsman GM, Khan M, Hammerman SM. Arthroscopic repair of full-thickness tears of the rotator cuff. J Bone Joint Surg Am 1998;80:832-840.