A technique for arthroscopic-assisted lower trapezius transfer using an Achilles tendon allograft augmented with acellular dermal matrix to treat posterior superior irreparable rotator cuff tears in the lateral decubitus position

Chang Hee Baek; Bo Taek Kim; Jung Gon Kim; Chaemoon Lim

doi:10.5397/cise.2024.00822

Abstract

Lower trapezius tendon transfer has emerged as an effective treatment option with promising clinical outcomes for patients with posterior superior irreparable rotator cuff tears (PSIRCTs). This technique has gained considerable attention for PSIRCTs, with various modifications proposed by different authors. In this report, we present an arthroscopic-assisted approach to lower trapezius tendon transfer in patients with PSIRCT using an Achilles tendon allograft that is reinforced with an acellular dermal matrix graft. The procedure is conducted with the patient in the lateral decubitus position.

Key Words: Lower trapezius tendon transfer; Irreparable rotator cuff tears; Tendon transfer; Rotator cuff; Achilles tendon

Posterior superior irreparable rotator cuff tears (PSIRCTs) often lead to significant functional impairments, including reduced active range of motion and shoulder weakness, which hinder daily activities [1]. Among the various joint-preserving techniques, lower trapezius tendon (LTT) transfer has garnered increasing attention, especially in cases of PSIRCTs, with or without external rotation deficiency [2]. The LTT transfer, which was first introduced by Elhassan et al. [2], has shown sustained efficacy and has satisfied midterm follow-up results, as reported by Baek et al. [1] The success of LTT transfer is largely due to its biomechanical and anatomical properties [3]. The LTT transfer allows re-centering of the humeral head by restoring the balance between the anterior and posterior force couples, which is often disrupted in PSIRCTs [3]. Additionally, its excursion and line of pull to the native infraspinatus contribute to its biomechanical effectiveness and promising clinical outcomes [3,4].

Previously, we on a technique using a fascia lata autograft with a modified double-row suture bridge for LTT transfer [5]. However, this approach requires harvest of the fascia lata from the ipsilateral thigh, which leads to longer operative times and potential donor-site morbidity. It also increases the risk of medial graft tearing due to the tension exerted by the tied medial suture rows. In this technical note, we describe the treatment of PSIRCT with an arthroscopic-assisted LTT transfer with the patient in the lateral decubitus position; our technique employed an Achilles tendon allograft augmented with an acellular dermal matrix (ADM) graft and side-to-side suturing to the remaining posterior rotator cuffs.

This study was reviewed and approved by the public Institutional Review Board designated by Ministry of Health and Welfare (No. P01-202305-01-006). Requirement for informed consent was waived.

TECHNIQUE

Indications

(1) PSIRCT. (2) Advanced fatty infiltration of the posterior superior rotator cuff muscles (Goutallier classification grades 3 and 4). (3) Non-arthritic shoulder (Hamada stage ≤2). (4) Significant medial retraction of the torn posterior superior rotator cuff tendon, extending to the glenoid level.

Contraindications

(1) Glenohumeral arthritis (Hamada stage >3). (2) Irreparable subscapularis tear (Lafosse type ≥4). (3) Shoulder stiffness that may potentially affect the rehabilitation protocol. (4) Paralysis of the deltoid or trapezius muscles. (5) Active soft tissue infection in the shoulder.

Surgical Procedure

The complete surgical technique is demonstrated in Supplementary Video 1.

Arthroscopic preparation

The patient is placed under general anesthesia and positioned in the lateral decubitus position. The procedure utilizes posterior, anterior, lateral, and posterolateral portals as the main viewing and working sites. For footprint preparation, nonviable tissue remnants in the footprint of the supraspinatus are debrided. Approximately 5 mm of medialization of the articular cartilage of the humerus is performed to increase the attachment area for interpositional graft fixation. The first medial-row anchor (5.5 mm Healicoil suture anchor; Smith & Nephew) is inserted into the posteromedial corner of the footprint. Using a 45° Curved SutureLasso SD (Arthrex), three suture limbs (side-to-side sutures) from the anchor are passed through the anterior portion of the remaining infraspinatus muscle or teres minor in a medial-to-lateral direction with equal spacing. A second medial-row anchor (5.5-mm Healicoil suture anchor) is positioned 1.5 cm anterior to the first anchor to further compress the interpositional graft to the footprint. One suture from the second anchor is left in place while the other two are removed (Fig. 1A).

Interpositional graft

For the interpositional graft material, an Achilles tendon allograft is prepared. After excising the calcaneal bone section of the allograft, the Achilles tendon allograft is augmented with an ADM graft (SureDerm; Hans Biomed Co.). The size of the ADM graft can be adjusted based on the size of the footprint area. Two #2 sutures are used. One is placed anteriorly and one posteriorly on each lateral edge in a Krackow configuration to secure the ADM graft to the Achilles tendon allograft.

Harvest LTT

To harvest the LTT, a 4–6-cm skin incision is made just below the medial third of the scapular spine (Fig. 2A). The lateral portion of the LTT, which is located beneath the triangular fat area, is identified through careful dissection. The LTT is then detached from the scapular spine (Fig. 2B). It is crucial to avoid dissection medially past the medial border of the scapula, as the spinal accessory nerve is situated approximately 2–3 cm medial to this border. A free traction suture is placed at the end (Fig. 2C and D).

Arthroscopic graft passage and fixation

Under the guidance of an arthroscope, a switching stick is inserted from the lateral portal to the interval between the posterior deltoid and the remaining posterior rotator cuff. The switching stick ultimately emerges through the opening at the back. An incision is made over the infraspinatus fascia. Next, the switching stick is replaced with a grasper to hold the sutures of the prepared interpositional graft, which is slowly pulled through the lateral portal. It is essential to visualize the interpositional graft delivery through the arthroscope to prevent flipping or twisting. The interpositional graft is positioned on the prepared footprint with extended distalization to ensure it fully covers the lateral edge of the greater tuberosity. The anterior and middle sutures of the interpositional graft are preloaded into the first 5.5-mm SwiveLock anchor and fixed to the anterior greater tuberosity. Suture limbs from the second medial-row anchor are threaded through the graft in a loop-slide configuration, and three from the first anchor complete side-to-side suturing with the posterior cuff. The second anchor compresses the anterior graft onto the humerus. Sutures from the second anchor and side-to-side sutures are preloaded into the third, fourth, and fifth SwiveLock anchors to secure the middle, posterior, and posterior edge of the graft, ensuring fixation to the humerus. Fixation is confirmed with the suture configuration as shown (Fig. 1B-D).

Graft attachment to LTT and closing

When attaching the interpositional graft to the LTT, the arm is positioned at 45° of abduction with external rotation at 60° and the elbow is fully extended. The interpositional graft is wrapped anteriorly and posteriorly along the inferior margin of the lower trapezius muscle using one #2 suture in a Krackow configuration (Fig. 3A). Once secured, the lower trapezius muscle and interpositional graft move as a single unit during shoulder external rotation (Fig. 3B). The arthroscopic portals are closed, the LTT incision is layered and stapled, and standard dressings are applied.

Postoperative rehabilitation

Postoperatively, the patient wears a brace maintaining the shoulder at 0° external rotation for 4 weeks. During this period, continuous passive motion therapy is performed. After 4 weeks, active-assisted range of motion, physical therapy, and elastic band external rotation strengthening exercises are introduced. Heavy work and sports are restricted for 3 months.

DISCUSSION

In 2016, Elhassan et al. [2] first introduced the technique of arthroscopic-assisted LTT transfer for managing PSIRCTs. The success of the procedure is rooted in its anatomical and biomechanical advantages, as the LTT closely mimics the infraspinatus' line of pull, restoring shoulder biomechanics and improving anterior-posterior force coupling [3,4]. Various surgical modifications have been explored to further enhance its effectiveness. Ek et al. [6] retained the calcaneal bone insertion in the interpositional graft to promote bone-to-bone healing. Tang and Zhao [7] employed a humeral bone tunnel-based technique using graft implantation to enhance fixation strength.

Elhassan et al. [2] initially described the technique using an Achilles tendon allograft, which has since become a common choice due to its availability from tissue banks, reduced surgical time, and the advantage of avoiding donor site morbidity. However, despite its benefits, concerns persist regarding the cost, limited viability, potential for graft rejection, and susceptibility to infections. In response to these challenges, alternative graft options have been explored. Almeida et al. [8] integrated an autologous hamstring tendon, while Valenti and Werthel [9] employed an autologous semitendinosus tendon for the procedure. Additionally, Baek et al. [5] described the LTT transfer technique using fascia lata autograft. Autografts are known to minimize inflammatory responses, reduce revision rates, lower infection risk, and promote better healing, potentially reducing complications typically associated with allografts. However, no clear consensus has been established regarding the superiority of one graft type over another.

In our technique, we employ several distinct strategies to enhance the effectiveness of LTT transfers. First, we augment the Achilles tendon allograft with an ADM graft to improve its properties. When the thick graft is positioned in the supraspinatus footprint, it mimics the effect of biologic tuberoplasty by reducing the bone-to-bone contact between the greater tuberosity and the acromion. Additionally, biomechanical studies have shown that ADM graft augmentation provides a biocompatible scaffold, excellent suture retention properties, and significant tensile strength, all of which enhance the durability of the repair [10]. Second, we incorporate three side-to-side sutures between the interpositional graft and the remaining posterior rotator cuff muscles to reinforce the graft stability and to promote vascularization and synovialization of the graft. We also medialize the articular cartilage and distalize the interpositional graft beyond the lateral edge of the greater tuberosity, increasing the contact area with the humeral attachment site to enhance healing. Furthermore, we use the "wrap-around" technique to attach the graft to the LTT, which enhances the contact area and promotes graft integration. Despite the advantages and limitations outlined in Table 1, we present a new technique for arthroscopic-assisted LTT transfers using an Achilles tendon allograft augmented with an ADM graft in the lateral decubitus position. This technique offers a promising method for treating PSIRCTs.

NOTES

Author contributions

Conceptualization: CHB, BTK, JGK, CL. Investigation: CHB, BTK, JGK, CL. Methodology: CHB, BTK, JGK, CL. Resources: CHB, BTK. Supervision: CHB, JGK, CL. Validation: CHB, BTK, JGK, CL. Visualization: CHB, BTK. Writing – original draft: BTK. Writing – review & editing: BTK. CHB. All authors read and agreed to the published version of the manuscript.

Conflict of interest

None.

Funding

None.

Data availability

None.

Acknowledgments

The authors would like to extend a special thank you to Yeong Ran Seo, Hyun Mi Kim, Seung Hwan Oh, and Seul Gi Yun for their help.

SUPPLEMENTARY MATERIALS

Supplementary materials can be found via https://doi.org/10.5397/cise.2024.00822.

Supplementary Video 1.

In this video, we describe the surgical steps of arthroscopic-assisted lower trapezius transfer using an Achilles tendon allograft augmented with an acellular dermal matrix graft for posterior superior irreparable rotator cuff tears. The surgery was performed on the right shoulder in the lateral decubitus position.

Fig. 1.

(A) Arthroscopic image from lateral portal first medial-row suture anchor (red arrow) inserted in the posteromedial corner of the footprint. The second medial-row suture anchor (white arrow) is placed anteriorly to first medial-row suture anchor. (B) Initial configuration of suture placement. (C) Final configuration of suture placement. (D) Arthroscopic image from lateral portal showing final appearance of the interpositional graft (white asterisk) firmly fixed to the footprint.

Fig. 2.

(A) Subcutaneous layer is shown after the incision. (B) Lower trapezius tendon (white asterisk) is identified. (C) Lower trapezius tendon (white asterisk) is prepared with No. 2 non-absorbable suture at the end. (D) Thick fascia (red asterisk) of lower trapezius muscle can be seen when it is reflected.

Fig. 3.

(A) With the right shoulder in the decubitus position, an interpositional graft (white arrow) is wrapped along the inferior border of lower trapezius (white asterisk), covering anteriorly and posteriorly. (B) Final appearance of the interpositional graft (white arrow) fixed to the lower trapezius (white asterisk).

Table 1.

Advantages and limitations

Advantage	Rebalance the transverse force couple
	Provide spacer effect in the subacromial space
	Reduce surgical time using an allograft
	Biomechanical advantages of augmentation with acellular dermal matrix
	Natural physiological advantage of the lateral decubitus position
	Better stability of the interpositional graft by side-to-side suturing
Limitation	Extensive techniques
	Relatively higher risk of infection due to usage of an allograft
	Increase in cost due to usage of acellular dermal matrix and allograft
	No long-term clinical results

REFERENCES

1. Baek CH, Kim BT, Kim JG, Kim SJ. Mid-term outcomes of arthroscopically assisted lower trapezius tendon transfer using Achilles allograft in treatment of posterior-superior irreparable rotator cuff tear. J Shoulder Elbow Surg 2024;33:1293–305.

2. Elhassan BT, Alentorn-Geli E, Assenmacher AT, Wagner ER. Arthroscopic-assisted lower trapezius tendon transfer for massive irreparable posterior-superior rotator cuff tears: surgical technique. Arthrosc Tech 2016;5:e981–8.

3. Reddy A, Gulotta LV, Chen X, et al. Biomechanics of lower trapezius and latissimus dorsi transfers in rotator cuff-deficient shoulders. J Shoulder Elbow Surg 2019;28:1257–64.

4. Baek G, Kim JG, Baek GR, et al. Biomechanical comparison between superior capsular reconstruction and lower trapezius tendon transfer in irreparable posterosuperior rotator cuff tears. Am J Sports Med 2024;52:1419–27.

5. Baek CH, Kim BT, Kim JG. Arthroscopic-assisted middle trapezius transfer using an achilles tendon allograft in treatment of isolated supraspinatus irreparable rotator cuff tears in lateral decubitus position. Arthrosc Tech 2024;13:102976.

6. Ek ET, Lording T, McBride AP. Arthroscopic-assisted lower trapezius tendon transfer for massive irreparable posterosuperior rotator cuff tears using an achilles tendon-bone allograft. Arthrosc Tech 2020;9:e1759–66.

7. Tang J, Zhao J. Arthroscopic humeral bone tunnel-based tendon grafting and trapezius transfer for irreparable posterior superior rotator cuff tear. Arthrosc Tech 2021;10:e1079–87.

8. Almeida TB, Pascarelli L, Bongiovanni RR, Tamaoki MJ, Rodrigues LM. Outcomes of lower trapezius transfer with hamstring tendons for irreparable rotator cuff tears. Shoulder Elbow 2023;15(4 Suppl):63–71.

9. Valenti P, Werthel JD. Lower trapezius transfer with semitendinosus tendon augmentation: indication, technique, results. Obere Extrem 2018;13:261–8.

10. Omae H, Steinmann SP, Zhao C, et al. Biomechanical effect of rotator cuff augmentation with an acellular dermal matrix graft: a cadaver study. Clin Biomech (Bristol) 2012;27:789–92.