Surgical Management of Massive Irreparable Posterosuperior Rotator Cuff Tears: Arthroscopic-Assisted Lower Trapezius Transfer

Abstract

Purpose of the Review

Functionally irreparable rotator cuff tears (FIRCTs) remain one of the most challenging pathologies treated in the shoulder. The lower trapezius transfer represents a very promising treatment option for posterosuperior FIRCT. This article reviews the role for the lower trapezius transfer in the treatment of patient with FIRCTs and highlights the tips and tricks to performing this arthroscopic-assisted procedure.

Recent Findings

The treatment of posterosuperior FIRCTs contemplates a wide array of surgical options, including partial repair, biceps tenodesis/tenotomy, superior capsule reconstruction, subacromial balloon, reverse shoulder arthroplasty, and open-/arthroscopic-assisted tendon transfers. Tendon transfers have emerged as very promising reconstructive options to rebalance the anterior-posterior force couple. Controversy remains regarding the relative indications of latissimus dorsi transfer (LDT) and lower trapezius transfer (LTT). Initially used with very good success in patients with brachial plexus injuries, the open LTT has shown excellent clinical and radiographic outcomes in a recent series of patients with FIRCTs. However, this technique should be reserved for patients with an intact or reparable subscapularis tendon and no advanced glenohumeral arthritis or humeral head femoralization. With advancements in surgical technique, the arthroscopic-assisted LTT has shown similar promising results. However, studies on arthroscopically assisted LTT are limited to short-term follow-up, and future comparative trials with large patient numbers and longer follow-up are needed to better understand the indications for this novel tendon transfer in the treatment of FIRCT.

Summary

The arthroscopic-assisted LTT is a novel, promising option for the treatment of patients with functional irreparable posterosuperior rotator cuff tears. Careful attention to indications and technical pearls are paramount when performing this procedure to optimize postoperative clinical outcomes.

Introduction

Massive rotator cuff tears in both the primary and revision setting commonly lead to severe shoulder pain and loss of function. The natural history of these tears if left untreated involves a predictable progression to arthritic changes [1–3]. They are characterized by their tendon retraction, poor tendon quality, and fatty muscle infiltration, all leading to the shoulder dysfunction and morbidity experienced by patients [4–7]. Although the definition of irreparability is controversial, many studies have shown worrisome re-tear rates ranging from 20 to 94%, often associated with poor clinical outcomes [8–11]. Therefore, even if the tear can be physically repaired to the rotator cuff footprint, many large tears are considered to be functionally irreparable rotator cuff tears (FIRCTs).

A patient with a FIRCT without arthritis may be offered a variety of treatment options, including partial repair [12–16], augmentation or bridging with allografts [17–22], superior capsular reconstruction [23–26], subacromial balloon [27], shoulder tendon transfers [28–39], and reverse shoulder arthroplasty [40–43]. The ultimate goal of all of these treatment options involves providing a stable fulcrum for the humeral head to rotate, either through an implant, static graft, or restoration of the anterior-posterior force couple. Tendon transfers represent a promising option to treat patients with FIRCTs, providing a dynamic replacement for the posterior aspect of the force couple. Although the latissimus dorsi transfer (LDT) historically has been historically associated with reliable outcomes in selected patients with posterosuperior FIRTCs [28–36], the lower trapezius transfer has emerged as a promising alternative that is potentially biomechanically superior and easier for patients to retrain [35, 37, 38, 44].

“Functionally” Irreparable Rotator Cuff Tears

Definition of Irreparability

The true definition of an irreparable rotator cuff tear is controversial given the multiple factors to consider, including patient factors, chronicity, imaging findings, and previous surgeries. However, all of these are critical to consider when deciding on whether or not to attempt a rotator cuff repair in the setting of a massive tear; as mentioned before, re-tear rates and associated clinical failures with these repairs can range from 20 to 94% [8–11].

Certain patient factors that may increase the risk of re-tear after an attempted repair include diabetes [45, 46], smoking [47], older age [46, 48], inflammatory arthritis [49], osteoporosis [50], and immunocompromised status [51]. Additionally, physical examination maneuvers can provide an insight on the size and chronicity of the tears, such as an external rotation lag sign [52]. Although not to be taken in isolation, when combined with other imaging or pathologic findings, they help the surgeon to determine the reparability of the tears.

One of the most important considerations when evaluating for FIRCTs involves the true chronicity of the tear. After the tear occurs, the involved rotator cuff tendon and muscle undergo a predictable pattern of degeneration over time, involving muscle shortening and retraction in the first year, followed by tendon shortening and muscle fatty infiltration in the following 2–4 years [53, 54]. This degenerative process influences the reparability of the tendon(s), including its intrinsic ability to heal back to the bone and functionally restore the shoulder’s coronal or axial force couple. An example of the influence of this process can be seen with improved healing rates and associated clinical outcomes within 6 months of a traumatic event [6, 55, 56].

Imaging plays a critical role in evaluating the chronicity of these tears and their ultimate reparability. Grashey and axillary radiographs might show humeral head superior or anterior subluxation, both late findings in the rotator cuff degenerative pathway. Computerized tomography arthrograms (CTA) and magnetic resonance imaging (MRI) represent a critical part to evaluating the quality of the rotator cuff and its potential reparability. Muscular fatty infiltration, visualized either via CTA [57] or MRI [58] on coronal or sagittal views, might be one of the most critical considerations when deciding the reparability and ultimate best treatment option (Fig. 1). Consistently throughout the last two decades, higher grades of fatty infiltration have been associated with worse outcomes and rates of rotator cuff healing [1, 6, 55, 59]. Additionally, tendon retraction to the level of the glenoid (Patte Classification [60] Grade 3) and a tendon length < 15 mm [59] have also been associated with worse clinical outcomes and higher re-tear rates. Combining advanced fatty infiltration, retraction to the level of the glenoid, and a tendon length < 15 mm, the specificity for an irreparable tear is 98% [61].

Fig. 1.

Fatty infiltration. A sagittal T1 view on an MRI shows advanced fatty infiltration (Grade 4 [1]) of the supraspinatus and infraspinatus tendons

Biomechanics of Irreparable Rotator Cuff Tears

The idea behind the “functional” definition of irreparable rotator cuff tears deals with the biomechanical impact on the shoulder. In a healthy shoulder, the rotator cuff serve as the primary dynamic stabilizers of the humeral head, not only contributing to shoulder motion directly but also providing stability to allow the other muscles (e.g., deltoid) to power shoulder function [62]. Glenohumeral motion and its associated scapulohumeral rhythm requires a balance of these dynamic stabilizers, creating a force couple [62] and a coordinated equilibrium for humeral rotation [63]. However, when a rotator cuff tendon is either torn or functionally inadequate, the anterior-posterior force couple is lost, and the associated glenohumeral contact pressure is altered, leading to translation of the humeral head during motion [64]. This instability and dynamic translation compromises the patient’s function and underlies their associated pain and morbidity (Fig. 2).

Fig. 2.

Tendon retraction. A coronal T2 view on an MRI shows tendon retraction to the level of the glenoid, Patte Grade 3 [2]

Treatment of Irreparable Rotator Cuff Tears

Nonoperative Treatment

Although it is very reasonable to try nonoperative measures, such as physical therapy, nonsteroidal anti-inflammatory drugs, and corticosteroid injections in patients who wish to avoid surgery, there is no evidence to support that these or other nonoperative treatment modalities alter the natural history of massive rotator cuff tears [2, 3, 65]. Nonetheless, most surgeons would recommend at least 3–6 months of these nonoperative measures prior to considering a reconstructive surgical intervention.

Surgical Options for Irreparable Rotator Cuff Tears

There are many options for surgeons when treating FIRCTs without arthritis, including partial repair [15, 66], augmentation or bridging with allografts [17–22], superior capsular reconstruction [23–26], subacromial balloon [27], reverse shoulder arthroplasty [40–43], and tendon transfers including the latissimus dorsi [28–36, 67] and lower trapezius transfer [37, 38, 44]. The results of partial repair [15] deteriorate with time, while the reported outcomes of graft augmentation and superior capsular reconstruction are limited to relatively small case series with short-term follow-up. Alternatively, the reverse shoulder arthroplasty, originally introduced for the treatment of massive rotator cuff tears by Paul Grammont [41•], provides very reproducible results for FIRCTs [40–43]. However, this joint replacement procedure has been associated with complications [42, 68] and functional limitations [69, 70] in certain patient populations.

Tendon Transfers for Irreparable Rotator Cuff Tears

Over the last 30 years, tendon transfers have been proven to be able to reliably restore shoulder function and decrease associated pain in patients with posterosuperior FIRCTs [28–38]. This is likely the result of their ability to dynamically restore the shoulder’s anterior-posterior force couple. Transfer of a dynamic stabilizer that can be trained to be synergistic to the torn tendon and non-functional muscle may balance the shoulder and restore the patient’s force couple. These transfers contribute directly to external rotation and abduction while stabilizing the pathologic translation of the humeral head. Whenever planning to perform a tendon transfer, there are a few important principles to follow [71, 72]:

1. Similar excursion between transferred and recipient muscle.

2. Expendable transferred muscle without compromising shoulder function.

3. Similar line of pull between the transferred tendon and the recipient muscle.

4. Each tendon transferred should replace only 1 function of the recipient.

The open LDT has historically been the most studied transfer for posterosuperior FIRCT, with good clinical and radiographic outcomes reported for the past 10 years of follow-up [73]. However, some medium- to long-term studies have reported difficulty for patients retraining their transferred tendon [34•] and associated poor long-term outcomes [67]. Although the technique has been modified to be performed in an arthroscopic-assisted fashion, the studies examining this technique are limited to short-term follow-up case series [28, 30, 31].

The LTT has certain biomechanical and functional advantages that potentially overcome some of the limitations of the LDT, including an “in-line” transfer with a more favorable line of pull and an “in-phase” transfer that is easier for patients to retrain. Furthermore, once mastered, the harvest of the lower trapezius is potentially technically easier and faster than the latissimus dorsi.

Lower Trapezius Transfer

Indications

The LTT was initially described as a reliable method of restoring shoulder external rotation in patients with brachial plexus injuries [74]. Currently, its indications have been expanded to functionally irreparable posterosuperior rotator cuff tears, included prior failed rotator cuff repairs. Although the initial results have been promising in this patient population [37, 38], its success depends on proper patient selection (Table 1). Unlike the LDT [33, 34, 36, 73], the LTT has shown promising outcomes for patients with teres minor and subscapularis pathology, as well as those with pseudoparalysis [37, 38]. The following are the three of the most important considerations regarding LTT:

1. Intact or reparable subscapularis without dynamic anterosuperior escape: Given that this transfer acts dynamically to restore the posterior aspect of the force couple, it is critical to have the anterior aspect of the force couple intact or reparable.

2. Absence of rotator cuff arthropathy or advanced glenohumeral arthritis: Hamada [75] Grade 3 or higher with associated acetabularization of the acromion or femoralization of the humerus cannot be properly addressed by a joint preserving procedure.

3. Healthy deltoid: After restoring the force couple with a LTT, the deltoid will provide most of the power for active elevation. In the absence of a functioning deltoid, LTT may still be able restore external rotation, but naturally will not improve abduction or elevation.

Table 1.

Contraindications to lower trapezius transfer

Indicated if goal only external rotation*	Relative contraindications	Absolute contraindications
Deltoid paralysis	Advanced age (> 70–75 years)	Rotator cuff arthropathy grade 3 or higher [4]
Brachial plexus injury	Dynamic anterosuperior escape (± irreparable subscapularis)	Advanced glenohumeral arthritis
	Poor bone quality	Infection
	Poor compliance	Paralyzed trapezius muscle

*In the setting of deltoid paralysis or an irreparable subscapularis tear, the lower trapezius can still restore external rotation, but is not as effective at restoring abduction or elevation

Anatomy and Biomechanics

The lower trapezius tendon is one of the three parts of the trapezius muscle, functioning to stabilize the scapula and provide scapular external rotation [76]. It inserts on the medial aspect of the scapular spine, and it is innervated by the spinal accessory nerve, which travels medial to the medial angle of the scapula.

When comparing the LDT and LTT procedures, three biomechanical and anatomic advantages may favor LTT:

1. “In-line”: The lower trapezius tendon attached mimics the vector of the infraspinatus tendon (Fig. 3).

2. Moment arm: Recent biomechanical studies have found the LTT to have better abduction and external rotation moment arms compared with LDT [77–79].

3. “In-phase”: The lower trapezius muscle is activated in the native shoulder during external rotation, elevation, and abduction [80]. This makes it potentially easier for patients to retrain their LTT transfer. On the contrary, the latissimus dorsi tendon function in the native shoulder is adduction and internal rotation.

Fig. 3.

Line of pull. The line of pull of the infraspinatus (yellow arrow) is more similar to the lower trapezius (green arrow) than the latissimus dorsi (blue arrow)

Surgical Technique for Arthroscopically Assisted LTT

Although initially described as an open technique [37••], in recent years LTT has been modified to a less invasive arthroscopic-assisted technique [35, 38, 44, 81], avoiding the need to perform deltoid take-down or an acromial osteotomy or to perform the transfer. This avoids the potential danger of deltoid insufficiency, allows arthroscopic visualization of the passage between the deltoid and infraspinatus fascia, and has the potential to lead to less subacromial adhesions.

The arthroscopic-assisted LTT is performed in the beach chair position, with adequate draping of the surgical field beyond the medial aspect of the scapula [35, 44, 81]. We prefer to perform the tendon harvest prior to the arthroscopic portion in most cases. It is helpful to accurately draw out all the surface landmarks for both the tendon harvest and the arthroscopic portions of the transfer: the scapular spine and body, lower trapezius course (origin from mid-thoracic to T12; insertion on medial 3–5 cm of scapular spine), acromion, and coracoid. For tendon harvest, we have modified the previous technique [44•] to now use a horizontal incision just inferior to the scapular spine, from 4 cm lateral to the medial edge to 1 cm medial to the medial edge (Fig. 4). Prior to identifying the tendon, it is critical to excise out overlying adipose tissue. The lower trapezius tendon is then identified with the help of the fat triangle near the tendon insertion and the inferior muscle belly traveling diagonally up to the scapular spine. If the surgeon is having difficulty identifying this tendon, the bone “axilla” of the medial angle of the scapular spine can be used to identify the tendon running over the top of it (Fig. 5). It is critical to define the undersurface of the tendon/muscle, separating it from the underlying infraspinatus fascia. The tendon is then followed diagonally up to its insertion on the scapular spine and detached with electrocautery, mobilizing the lower trapezius from the infraspinatus fascia and middle trapezius. The lower and middle trapezius muscle bellies can be separated by following the horizontal part of the triangular tendinous insertion of the lower trapezius horizontally towards the mid-thoracic spine. Superficial dissection is very safe, but deep dissection medial to the medial scapular border beyond 2 cm should be avoided to protect the spinal accessory nerve in the deep fascia of the muscle. The tendon is then prepared to receive a #2 non-absorbable in a Krakow fashion to assist with mobilization (Fig. 6).

Fig. 4.

Incision. The landmarks are mapped out, and a horizontal incision is utilized just inferior to the scapular spine, from 4 cm lateral to the medial edge to 1 cm medial to the medial edge

Fig. 5.

Harvest. The “axilla” of the medial angle of the scapular spine can be used to identify the tendon, as well as the underlying infraspinatus fascia. The tendon then should be properly mobilized for superficial adhesions

Fig. 6.

Tendon preparation. The lower trapezius tendon is seen on the deep surface of the muscle and is prepared with a running Krackow suture to create a “bulls-eye” for the future Pulvertaft weave

To perform the arthroscopic portion, we utilize the lateral portal as the primary visualization portal and the anterior, medial, and anterolateral portals as working portals. After performing a diagnostic arthroscopy and subacromial decompression if needed, the irreparable portions of the rotator cuff are debrided, and any previous anchors or sutures are removed. The infraspinatus is prepared for a partial repair if possible. The subscapularis should also be repaired if necessary, prior to performing the transfer. If needed, a biceps tenodesis should also be performed prior to securing the graft. Then, the greater tuberosity is prepared to facilitate bone healing [82] (Fig. 7). If an infraspinatus repair is possible, this is performed prior to performing the transfer. Once ready for the transfer, the interval is developed between the infraspinatus superficial fascia and the deltoid muscle.

Fig. 7.

Footprint preparation. The greater tuberosity is prepared utilizing the “crimson duvet” technique to facilitate bone healing [3]

Switching back to the medial scapular incision, the infraspinatus fascia is incised along the lines of the muscle fibers to allow passage of the transferred tendon. Prior to the transfer, an Achilles allograft is prepared with two Krakow sutures and an overlapping baseball stitch on the narrower side of the graft (Fig. 8). A long arthroscopic grasper is then placed through the anterolateral portal out the medial incision to grasp the sutures attached to the allograft (Fig. 9). The sutures are then retrieved out the anterolateral portal. Suture management is key at this step to avoid any twists or knots in the sutures prior to placing the anchors.

Fig. 8.

Allograft preparation. The allograft is prepared with multiple Krackow sutures of different colors

Fig. 9.

Tendon transfer. A hip arthroscopy grasper is then placed through the anterolateral portal out the medial incision to grasp the sutures attached to the allograft

The allograft is then anchored into the tuberosity, using an anteromedial anchor just lateral to the articular surface and posterior to the bicipital groove, as well as an anterolateral anchor just off the ledge of the greater tuberosity, posterior to the bicipital groove (Fig. 10). Accessory medial and lateral sutures can be placed if desired for further footprint coverage. After fixing the allograft, multiple cycles of shoulder internal and external rotation are performed to increase the final tension of the allograft (Fig. 11).

Fig. 10.

Anchor placement. The anteromedial anchor (red circle) is placed just lateral to the articular surface and posterior to the bicipital groove (yellow oval), while the anterolateral anchor (blue circle) is placed just distal to the greater tuberosity footprint and posterior to the bicipital groove

Fig. 11.

Tendon orientation. The allograft is anchored in place to the tuberosity with 2 main and 2 accessory anchors for maximal footprint coverage, then splint in the medial incision for the pulvertaft weave

Attention is then directed back to the medial scapular incision. It is critical to place the arm in maximal external rotation in 60°–90° of abduction at this step. The allograft tendon is then split and secured to the lower trapezius using a Pulvertaft weave technique in maximal tension with multiple sutures (Fig. 12). Vancomycin powder is then placed, and the incision is closed in layered fashion prior to placing the patient in the external rotation immobilizer. The postoperative therapy protocol is summarized in Table 2.

Fig. 12.

Pulvertaft weave. The allograft is split, and Pulvertaft weave is performed to secure to the lower trapezius tendon, anchoring with multiple figure eight sutures in maximal possible tension

Table 2.

Postoperative therapy protocol

Postoperative time point	Activity
0 to 6–8 weeks	Custom external rotation brace, with shoulder maintained in 30°–40° abduction and 30°–40° of external rotation
6–8 to 12 weeks	Progression from passive to active-assisted to active shoulder motion with an internal rotation limit to neutral (0°). Pool-based exercises are started
12 to 16 weeks	Removal of internal rotation limit. Return to most activities of daily living. Pool-based exercises are continued
16 weeks to 6 months	Strengthening without limits on motion, focusing on the scapula motion as well as internal/external rotation, abduction
4–6 months	Return to full unrestricted activities

Tips and Tricks

Tips and tricks for this procedure can be found in Table 3. These are a few critical steps to perform this surgery and maximize the possibility of a successful outcome:

• Harvest (Fig. 5): It is critical to excise out the overlying fat and use reliable landmarks (e.g., “axilla” of medial scapula) to identify the tendon. Furthermore, in the infero-lateral aspect of the incision is the infraspinatus fascia, which can also help to identify the muscle belly. The tendon inserts on to the scapular spine posteriorly to the posterior deltoid, which can also be used as a landmark.

• Tendon mobilization (Fig. 6): It is important to release adhesions of the lower trapezius to the skin, release the superficial fascia between the middle and lower trapezius, and release the adhesions to the medial border of the scapula. The tendon should be able to almost reach the posterior portal of the arthroscopy.

• Allograft preparation (Fig. 8): The graft should be prepared either preoperatively or simultaneously during the procedure with 2–4 sutures to be anchored for maximal footprint compression.

• Simultaneous procedures: It is important to perform an adequate subscapularis and infraspinatus repair, when needed and possible, prior to performing the transfer. Biceps tenotomy or tenodesis can also be helpful to better visualize the optimal anchor placement.

• Anchor positions (Fig. 10): It is imperative to place the anteromedial anchor just lateral to the articular surface and posterior to the bicipital groove, while the anterolateral anchor should be placed just distal to the greater tuberosity footprint and posterior to the bicipital groove.

• Graft-tendon weave (Fig. 12): It is critical to place the arm in maximal external rotation and 60°–90° of abduction and to pull the maximal tension on the graft and tendon to achieve as tight of a weave as possible. It is almost impossible to overtension the reconstruction during step.

• Postoperative (Table 2): The patient must keep the arm in an external rotation immobilizer for 6–8 weeks and then cannot be permitted to do any internal rotation activities past neutral (0 degrees) for 12 weeks to avoid stretching the graft.

Table 3.

Tips and tricks

Step	Tip
Harvest	Excise fat overlying tendon and infraspinatus fascia
Landmarks	Use the “axilla” of the medial scapula, posterior deltoid, and underlying infraspinatus fascia as landmarks when identifying tendon
Lower vs middle	Separate lower trapezius from middle trapezius by following the triangle of underlying tendon, curving diagonally off the medial angle of the scapula
Mobilization	Release the superficial adhesions, adhesions to the medial angle of the scapula, and superficial fascia between lower and middle trapezius
Dangers	Avoid deep dissection medial to the medial border of the scapula to protect the neurovascular bundle
Concomitant procedures	Perform a tension-free subscapularis repair first, and then perform an infraspinatus repair if possible. By performing a biceps tenodesis after opening the groove, it can help with anchor placement
Footprint preparation	We prefer to use the crimson duvet technique to maximize graft-bone incorporation
Graft transfer	Use a hip arthroscopy grasper to bring sutures from graft into joint. Organize the sutures prior to pulling the graft into the joint
Anchor placement	Place the anteromedial anchor near the “L” made by the bicipital groove and the articular surface. Place the anterolateral anchor just off the tuberosity
Accessory anchors	Place accessory anchors medial or lateral to maximize footprint compression
Graft-tendon tension	Place the arm in maximal external rotation and 60°–90° of abduction, and pull maximal tension on the graft and tendon to achieve as tight of a weave as possible. Cannot overtension
Postoperative	Maintain external rotation immobilizer for 6–8 weeks; then no passive internal rotation until 12 weeks

Clinical and Radiographic Outcomes

Historically, the primary tendon transfer for irreparable posterosuperior rotator cuff tears has been the latissimus dorsi transfer (LDT). Since its initial description by Gerber et al. in 1998 [83], both the open technique [32, 72, 83–85] and more recently the arthroscopic-assisted technique [28, 31, 86–89] have been reported to provide good shoulder pain relief and functional improvements. Several factors seem to be associated with a worse outcome after this LDT, including prior rotator cuff repair [33, 36, 86, 90], pseudoparalysis [34, 86], poor subscapularis [33, 73, 90] or teres minor [36, 73] function, and critical shoulder angle > 35° [73]. For example, one biomechanical study showed that the external rotation and abduction forces after LDT are dependent on the counterbalancing forces of the subscapularis [91]. With subscapularis insufficiency, the humeral head translates anteriorly and inferiorly after the LDT. Additionally, Iannotti et al. found that patients with poor outcomes after LDT lacked synchronous, in-phase contraction of the “out of phase” latissimus dorsi [34].

Alternatively, the “in-phase” and “in-line” LTT theoretically overcomes many of these shortcomings. Since its original description by Elhassan et al. [74•] in 2009, it has been reported to successfully restore external rotation in the paralytic shoulder [72, 92, 93]. The ease and success with which patients are able to retrain their shoulder after the transfer is in part due to its “in-phase” contraction with the native shoulder external rotators and abductors [80], a similar excursion when compared with the infraspinatus [94], and “in-line” pull that simulates the infraspinatus vector (Fig. 2). In a study on the open LTT for FIRCTs, 33 patients followed for a mean of 47 months experienced good pain relief, improvements in external rotation and abduction, as well as patient-reported outcome measures (PROMs) [37••]. Outcomes were better in patients with preoperative elevation over 60°.

We prefer to perform this technique via the arthroscopic-assisted technique [35, 44]. Valenti et al. reported on 14 patients with external rotation lag and Hornblower’s signs who underwent LTT augmented with a semitendinosus autograft [38••]. At a mean follow-up of 24 months, patients improved their PROMs and pain scores by more than double, with only 1 revision procedure secondary to an infection and no graft tears. The two authors in this article have published [81••] on the largest series to date of arthroscopic-assisted LTT. Forty-one patients underwent the arthroscopic-assisted LTT, including 66% with a failed prior rotator cuff repair. Overall, 37 (90%) had excellent outcomes with improvements in all PROMs, shoulder function, and pain scores. Improved functional outcomes were seen in patients with shoulder flexion more than 60° and < 2 years’ time interval between symptoms and presentation for treatment. There were 4 (10%) failures, with an increased risk in those with advanced Hamada grades for rotator cuff arthropathy. Subscapularis or teres minor pathology, as well as pseudoparalysis, did not seem to impact the ultimate outcomes.

Conclusions

Transfer of the lower trapezius to the greater tuberosity represents a promising option to treat patients with functionally irreparable rotator cuff tears. Advances in surgical technique now allow this transfer to be performed arthroscopically assisted, potentially improving patient recovery and early functional gains. When considering the ideal tendon transfer for the management of FIRCTs, it is critical to consider classic tendon transfer principles, as well as the ability of the patients to retrain the new transfer to perform a different function. For the LTT, improved outcomes are particularly seen in patients with shoulder flexion more than 60 degrees, minimal to no arthritis of the shoulder, and < 2 years’ time interval between symptoms and presentation for treatment. Potential advantages for this tendon transfer include a similar excursion and “in-line” pull to the infraspinatus tendon, “in-phase” contraction with external rotation and abduction, less humeral head depression if subscapularis insufficiency, and minimally invasive approach avoiding an acromial osteotomy. However, the LTT is relatively new, and as such long-term outcomes studies are lacking; in addition, the LTT is an indirect transfer and thus potentially subjects to failure mechanisms associated with allograft failure. Future comparative trials with large patient numbers and longer follow-up are needed to better understand the indications for each of these transfers to treat these difficult pathologies.

Compliance with Ethical Standards

Conflict of Interest

Eric Wagner receives consulting fees from Stryker and research support from Arthrex, Konica Minolta, and DJO. None are relevant to this manuscript.

Bassem Elhassan receives consulting fees from Arthrex, DJO, and Integra.

Human and Animal Rights and Informed Consent

This article does not contain any studies with human or animal subjects performed by any of the authors.