Around the Campfire

Western Wisdom

The hottest fire is made by the wood you chop yourself.

As we all know, shoulder arthroscopy has changed the way we treat shoulder disorders and has continued to advance at a rapid pace. Since the first Cowboy’s Guide was released in 2006, a number of new techniques have gained increasing popularity necessitating this current companion guide. Furthermore, new scientific evidence has emerged addressing various controversies in shoulder arthroscopy, and this same evidence has created new fields and new questions. In this “campfire chat,” we discuss various topics related to arthroscopic shoulder surgery.

SINGLE-ROW VERSUS DOUBLE-ROW REPAIR FOR ROTATOR CUFF TEARS

Ian Lo, MD: Dr Burkhart, when I was a fellow with you in 2001, you showed me a case with 10-year follow-up of a double-row rotator cuff repair. You’ve obviously been performing double-row rotator cuff repairs for years. What is your current preferred technique for repair of a routine nonretracted tear of the supraspinatus tendon?

Stephen Burkhart, MD: Over many years, my technique of arthroscopic rotator cuff repair has evolved due to both changes in technology and research studies. Although I originally performed classical double-row techniques with medial mattress stitches and lateral simple stitches, my current technique incorporates linkage of the medial and lateral rows. I usually use two SwiveLock suture anchors medially and two SwiveLock suture anchors laterally with FiberTape passed in a SpeedBridge (Arthrex, Inc., Naples, FL) crisscrossing fashion between the two rows of anchors. I also tie the medial safety sutures together in a double-pulley fashion to maximize medial footprint coverage and seal the repair site from joint fluid.

I.L.: You obviously prefer double-row repairs whenever possible. How important is it to link the two rows of suture anchors together?

S.B.: Linking the two rows of suture anchors has multiple advantages. By crisscrossing the sutures and having them span over the rotator cuff surface, this evenly distributes force across each of the suture anchors, maximizes footprint contact area and pressure, and creates a self-reinforcing system. Similar to a Chinese finger trap, a self-reinforcing system tightens as load is applied. In the case of a rotator cuff tear that is repaired using this technique, as tension is applied to the rotator cuff tendon the footprint contact pressures actually increase, further stabilizing the construct and minimizing gap formation.

I.L.: That seems like a very strong construct in theory. However, how do we put that into practice? There seems to be recently a lot of concern about overtensioning the spanning sutures and devascularizing the tendon. Paul, what practical tips are there to maximize fixation and contact pressure while respecting the biology of the tissue?

Paul Brady, MD.: Whenever I’m repairing a rotator cuff I like to think of two things, achieving a stable rotator cuff repair construct and enhancing the biology of the repair as well. It’s important to remember that both are critically important in obtaining a healed, functional rotator cuff. In regard to tension, there is medial to lateral tensioning of the torn cuff and there are compressive stabilization forces of the tendon against the bone. While it is critically important to not overtension the repaired tendon from a medial to lateral standpoint, applying compressive force of the repaired tendon against the bone is a good thing. Currently, when I apply compressive forces to the rotator cuff tendon against the bone, I compress until there is tissue indentation, indicating adequate contact pressure against the footprint. Although there is no doubt that overcompressing the sutures is possible, in practice I think that’s pretty difficult. Recent studies have shown that even though the transosseous-equivalent technique has the highest contact pressures when compared to other double-row designs, the contact pressures decrease over time as the tendon–bone interface reaches a new steady state level. So that in vivo, I don’t think that there is a significant problem with devascularizing the tendon.

It should also be remembered that the tendon itself is a relatively avascular tissue and the majority of the vascular supply, blood vessel ingrowth, and cell migration occurs from the adjacent bone. In fact, blood flow studies have demonstrated that the majority of blood flow comes from the anchors sites. That’s why I spend time preparing the bone bed and I like to use cannulated, vented anchors whenever possible (BioComposite SwiveLock C and BioComposite Corkscrew FT; Arthrex, Inc., Naples, FL). These anchors are composed of tricalcium phosphate. I believe that the vents in these anchors allow access channels from the deeper marrow elements to the repair site, enhancing the biological milieu at the repair site while still providing stable fixation.

I.L.: Those are some good tips, Paul. If you usually do double-row repairs, then when do you perform a single-row repair? Is it ever indicated?

P.B.: My major indication for a single-row repair is when the mobility of the tendon is insufficient to perform a double-row repair. I would never advocate overtensioning a repair just to obtain a double-row construct. We already know that tension overload is a major cause of repair failure. If I’m faced with a situation where there is minimal mobility of the tendon despite mobilization techniques, like a double interval slide case, I will perform a single-row rotator cuff repair. The second situation in which I will only utilize a single-row repair is if I have an isolated small bursal-sided partial-thickness tear or an upper subscapularis tear. Sometimes I will only utilize one anchor for such a repair. Also, if there is tendon loss, as when there is a significant tendon stump on the tuberosity, I will do a single-row repair. The key is to place the medial fixation point 2 or 3 mm lateral to the musculotendinous junction. You should never medialize your sutures beyond that point. If the tissue quality is poor, I’ll also augment the fixation utilizing a tissue-grasping suturing technique like a modified Mason Allen stitch or MAC stitch.

I.L.: I agree. The other place I will perform a single-row repair is with chronic subscapularis tendon tears. Many times even with a three-sided release, excursion is sufficient for only a single-row repair, which still provides a very secure repair. However, if there is enough excursion, I will still perform a double-row subscapularis repair to maximize the repair construct.

P.B.: That can be a pretty tight space anteriorly. Do you have any tips for double-row repair of the subscapularis?

I.L.: Well, all the standard techniques must be used to maximize the anterior working space. This includes the posterior lever push, internal rotation, and addressing the subscapularis tendon early in the procedure. Then, we perform a transosseous-equivalent technique usually using BioComposite Corkscrew FT anchors medially and BioComposite PushLock or BioComposite SwiveLock C anchors (Arthrex, Inc., Naples, FL) laterally. We pass the medial sutures individually as mattress sutures and tie the sutures. However, when you tie the sutures medially, this usually reduces the tendon to the bone bed and obstructs visualization from a posterior glenohumeral portal. Therefore, to visualize the repair site, I’ll use the anterosuperolateral portal as the viewing portal and create accessory anterolateral portals for insertion of the BioComposite PushLock or SwiveLock anchors laterally. The other tip is that if you’re running out of lesser tuberosity for anchor insertion, you can cheat slightly into the bicipital groove, which has good bone quality. You just have to be cognizant about the biceps tendon and any previously performed or planned biceps tenodesis.

P.B.: Those are fantastic tips, Ian. I also frequently perform a coracoplasty very early during my subscapularis work. Clearing this space anteriorly can increase visualization significantly as well.

SUBSCAPULARIS REPAIRS

I.L: Speaking of subscapularis tendon tears, Dr Burkhart, you’ve pretty much developed and championed the field of arthroscopic repair of the subscapularis tendon. Do you always repair a torn subscapularis? Have you ever just debrided a tear of the upper subscapularis?

S.B.: In my mind, the subscapularis tendon is the most important rotator cuff tendon and any pathology should be addressed. It’s anatomically a large tendon, it’s important in anterior instability, and it forms the anterior moment of the transverse plane force couple. Unrecognized subscapularis tendon pathology that goes unrepaired is a significant cause of poor outcome following rotator cuff repair. With that in mind, I treat the subscapularis tendon similar to the way that you would treat a supraspinatus tendon tear. If a patient had a full-thickness 1-cm tear of the supraspinatus tendon, wouldn’t you repair it? Of course, you would. And you should do the same for the subscapularis. If a patient has a full-thickness tear of the upper 1 cm of the subscapularis tendon, I would repair it. I treat partial tears in a similar fashion. If the partial tear appears to involve greater than one-third of the tendon thickness, especially if I’m worried about incompetence of the medial sling with biceps subluxation, I will repair the partial-thickness subscapularis tendon as well as address the biceps tendon. In active patients, I prefer biceps tenodesis over tenotomy.

I believe that over the long term, debridement of a full-thickness upper subscapularis tendon tear will likely fare similarly to debridement of full-thickness supraspinatus tendon tears. The results will likely deteriorate over time. I would only consider debridement of a subscapularis tendon tear in an elderly patient with limited goals who might not want to have a prolonged rehabilitation period. In this scenario of an elderly low-demand patient, I would probably address the biceps tendon with a biceps tenotomy as well.

I.L.: How about the coracoid, Paul? Do you always perform a coracoplasty when you repair a subscapularis? What are your indications for a coracoplasty?

P.B.: Performing a coracoplasty in conjunction with a subscapularis tendon repair is a common procedure. But it is not performed all the time. First, we should differentiate clearing of the soft tissues off the undersurface of the coracoid and subcoracoid space from actual bony resection of the coracoid tip or coracoplasty. Performing the soft tissue subcoracoid bursectomy is important and I perform this on almost all cases of full-thickness tears of the subscapularis. I perform this routinely since clearing of the soft tissues improves visualization and mobility, and allows for a tension-free repair.

My trigger for a coracoplasty is light. I think the morbidity of a coracoplasty is minimal (much like an acromioplasty) and the potential benefit is great. When clearing the rotator interval tissue, I always expose the coracoid tip in a patient with any subscapularis pathology. If the tip of a shaver, which has a width of 5 mm, fits easily between the coracoid tip and the subscapularis, I do not perform a coracoplasty. If it is tight whatsoever—off with the coracoid tip!

When performing the coracoplasty, I’m careful to both keep the plane of resection parallel to the plane of the subscapularis and maintain the integrity of the coracoacromial arch and the conjoint tendon.

I.L.: Dr Burkhart, let’s talk about extremely retracted subscapularis tendon tears. How far medial do you dissect the subscapularis tendon?

S.B.: My routine is to perform a three-sided release of the subscapularis tendon by resecting the rotator interval, skeletonizing the posterolateral coracoid, decompressing the subcoracoid space, releasing the middle glenohumeral ligament, releasing the adhesions between the inferolateral border of the coracoid neck and the superior border of the subscapularis with an arthroscopic elevator, and releasing the adhesions between the anterior glenoid neck and the posterior subscapularis with an arthroscopic elevator. In the vast majority of cases, a three-sided release will provide sufficient mobility for tendon reduction to the anatomic bone bed. I don’t believe that more aggressive mobilization is required in routine cases, and medial dissection is potentially dangerous. When I’m performing dissection around the coracoid, I stay on the posterolateral aspect of the coracoid and do not dissect medial to the coracoid or the conjoint tendon. Such medial dissection is unnecessary for subscapularis tendon mobilization and risks injury to the brachial plexus and other important neurovascular structures. Dissection of the axillary or subscapular nerves is unnecessary and does not improve mobility of the subscapularis.

I.L.: Well, that makes sense. What do you do in cases where you have improved mobility but not anatomically to the bone bed?

S.B.: In this scenario, I’ll medialize the bone bed by up to 7 mm. I’ll do this not only to allow reduction to the bone but also to improve tendon-to-bone contact when there is sufficient mobility. We have shown that we can safely medialize the bone bed by 7 mm to maximize tendon contact without a loss of internal rotation range of motion. In these cases, which are almost always salvage subscapularis tendon cases, I believe it’s important to restore the anterior moment and balance the force couples about the shoulder. Furthermore, the only other reasonable alternative is to perform a subcoracoid pectoralis major transfer, which is a major reconstructive procedure and is seldom necessary.

I.L.: Let’s just move back to the biceps tendon. How do you decide when to perform a biceps tenodesis and with what technique?

S.B.: In the vast majority of cases of subscapularis tears, even upper subscapularis tears, there is disruption of the medial sling resulting in biceps instability. Therefore, the biceps tendon must be addressed. Failure to address the biceps may result in ongoing biceps instability, and this can disrupt the subscapularis repair. Furthermore, by addressing the biceps tendon early in the procedure, visualization of the subscapularis tear is improved. It’s my routine to perform a biceps tenodesis, except in elderly low-demand patients where a biceps tenotomy will suffice. I prefer using a 7 or 8-mm BioComposite Tenodesis screw, performing the tenodesis in the upper portion of the bicipital groove.

PASTA LESIONS

I.L.: Okay, let’s move on to another controversial topic, partial-thickness tears of the articular surface of the rotator cuff or the so-called partial articular surface tendon avulsion (PASTA) lesion. Let’s suppose you have a tear involving 50% of the tendon thickness. Paul, what’s your preferred repair technique?

P.B.:

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