The Modified Single-working Portal Technique Using Lasso-loop Stitch with Needle for Arthroscopic Subscapularis Repair

Summary

We propose a modified arthroscopic technique of suturing the subscapular using a needle-through-line Lasso-loop through a unilateral anterior portal.

Abstract

Traditional shoulder arthroscopy typically requires both anterior and posterior portals. However, in the traditional anterior portal, simultaneous operation of the suture device and the gripper is not possible, necessitating an additional anterolateral portal for anchor insertion and suture delivery, which poses technical challenges for novice surgeons. Additionally, the ulnar side of the conventional rotator cuff suture hook is large, and it frequently causes iatrogenic damage to rotator cuff tissues. Therefore, we propose a modified arthroscopic technique that uses a 16 G needle for suture passage, eliminating the need for traditional suture devices, which is easily available and effective in reducing iatrogenic injury to the rotator cuff. This approach not only resolves instrument collision and visualization challenges inherent to single-portal arthroscopy, but also innovatively converts the arthroscopic suture technique into an extracorporeal Lasso-loop configuration. This significantly simplifies the operation; moreover, Lasso-loop suture is more stable and can reduce the cost and increase the operation benefit without using other consumables.

Introduction

The subscapularis muscle, the largest in the rotator cuff group, originates from the anterior surface of the scapula and merges into a robust tendon attaching to the lesser tuberosity¹. As a key element of the glenohumeral joint's transverse force couple, the subscapularis primarily facilitates internal rotation of the humerus and plays a pivotal role in shoulder dynamics². Subscapularis tears are typically not isolated and are frequently associated with supraspinatus tendon tears. These tears often manifest as partial articular-sided lesions at the superior third of the tendon³, marked by their subtlety and complexity in diagnosis and arthroscopic management.

The inaugural description of arthroscopic subscapularis repair was provided by Burkhart and Tehrany⁴ in 2002, with advancements such as single-row and double-row repairs emerging rapidly thereafter.But the unique anatomical characteristics of subscapularis tendon tears present particular technical challenges for arthroscopic repair. The primary difficulties manifest in two key aspects⁵: First, the severely restricted subcoracoid working space significantly compromises surgical field exposure and markedly limits instrument maneuverability. Second, the close anatomical proximity to the brachial plexus and vascular structures substantially increases the risk of neurovascular injury when addressing severely adhered and retracted tear patterns.

Traditional shoulder arthroscopy typically requires both anterior and posterior portals. However, in the traditional anterior portal, simultaneous operation of the suture device and the gripper is not possible, necessitating an additional anterolateral portal for anchor insertion and suture delivery. Additionally, the conventional rotator cuff suture hook's larger ulnar side often causes iatrogenic damage to the rotator cuff tissue. However, recent developments have introduced simpler, less invasive single-portal techniques, though these methods can present challenges in suture management and may increase trauma^5,6.

The lasso-loop stitch is a self-locking, self-cinching suture technique. Biomechanical studies have demonstrated that this configuration provides significantly greater tissue-holding strength compared to non-cinching suture constructs of equivalent configuration^7,8. Due to its reliable mechanical stability and clinical efficacy, the lasso-loop stitch has been widely adopted in shoulder surgery. However, the lasso-loop sutures in subscapularis tendon repair have not been previously documented in the literature, a finding that may be attributed to the aforementioned technical challenges associated with subscapularis repair.

We propose a modified arthroscopic technique that simplifies the suturing of the subscapular muscle. This method employs a needle-through-line Lasso-loop approach via a unilateral anterior portal. Our approach not only minimizes invasiveness but also enhances ease of execution, stability, and effectiveness of the repair. This technique is designed to overcome the limitations associated with traditional methods, offering a streamlined alternative that reduces operational complexity and potential for tissue trauma. Subscapular tear is usually not isolated. If it is combined with biceps longhead tendinopathy, depending on the patient's age, either a biceps tenotomy or an intra-articular tenodesis was performed, with tenotomy typically chosen for patients aged 60 years or older..

Protocol

All procedures involving human participants were part of a retrospective study; therefore, the Ethics Committee of Zhuhai People's Hospital has waived the ethical review requirements for this research. Written informed consent was obtained from patients for the use of their surgical videos (see Supplemental File 1).

1. Medical history collection

1. Clinical history
   1. Gather detailed histories, focusing on anterior shoulder pain, weak internal rotation, and symptoms worsening at night, affecting sleep.
2. Inclusion and exclusion criteria
   1. Set the following inclusion criteria: Patients with Lafosse classification ⁹I and II SSC injuries from January to December 2022 (Table 1); aged 40 to 70 years; no trauma history, indicating degenerative origin; reoperative MRI showing corso-brachial spacing < 6 mm; dominant hand affected.
   2. Set the following exclusion criteria: congenital or secondary shoulder deformities; brachial plexus injuries or muscle atrophy; high postoperative activity needs; other rotator cuff injuries; conditions like diabetes or severe osteoporosis; multiple hormone injections.

2. Clinical examination

1. Evaluate the pain site, tenderness, and both active and passive shoulder motions, emphasizing internal rotation.
2. Conduct special physical tests such as the Bear-Hug and Belly PrePress tests¹⁰ to assess the condition further.
3. Carry out preoperative and postoperative assessments, including comparisons of the VAS, Constant-Murley shoulder scores, ASES scores, shoulder motion range, and MRI results.

3. Surgical technique

1. Patient preparation and portal establishment
   1. Position the patient laterally and fix the affected upper limb in traction at 45°of abduction and 20° of forward flexion after general anesthesia (Propofol +Fentanyl+ Rocuronium + Sevoflurane).
   2. Establish a posterior portal 2 cm below and 1 cm medial to the acromion's posterolateral corner. Introduce a 30° arthroscope for joint evaluation. Create an anterior portal near the lateral aspect of the subscapularis (Figure 1A).
2. Tear detection and anchor implantation
   1. Identify the superior third of the subscapular tear via the posterior portal (Figure 1B). Release the subscapular tendon to cover the lesser tuberosity. Freshen the lesser tuberosity to induce bleeding.
   2. Implant a two-load anchor into the muscle's footprint (Figure 1C,D).
3. Needle suture passing with lasso-loop in arthroscopy
   1. Prepare a 16 G indwelling needle loaded with a PDS suture, leaving half outside to form a loop (Figure 2A).
   2. Insert the needle through the tear from the anterior portal, adjust the loop size, and withdraw slowly (Figure 2B-D).
   3. Pull out the PDS thread loop and one of the white and blue anchor sutures through the anterior portal with a grasper (Figure 2E,F).
4. Lasso-loop suture passing in vitro
   1. Pass two anchor sutures completely through the PDS thread loop in vitro (Figure 3A,B).
   2. Pull the PDS loop to pass the mid-portion of the anchor suture through and create a suture loop in the SSC.
   3. Pass the free end of the suture through this suture loop and pull it tight to form a self-cinching stitch of SSC (Figure 3C-H).
5. Knotting and fixation
   NOTE: Do not tighten the self-cinching stitch or it will move the subscapularis away the lesser tuberosity footprint (Figure 4A).
   1. Tighten the other end of the anchor suture to to secure the subscapularis to the lesser tuberosity (Figure 4B).
   2. Grab the two ends of the white and blue anchor sutures; tie and fix them successively (Figure 4C).

4. Postoperative care

1. Immobilize the shoulder for 4 weeks to avoid active lifting and excessive movements.
2. Start grip exercises and elbow flexion the day after surgery.
3. Start rehabilitation with passive shoulder rotations on day 3; advance to active motion exercises after a month; and start muscle strengthening and functional exercises in the third month.

Results

All 18 patients were followed up for a period ranging from 6 to 12 months, with an average of 8.7 months. The outcomes assessed include:

Pain and functionality scores
The Visual Analog Scale (VAS) for pain, Constant-Murley shoulder score, and American Shoulder and Elbow Surgeons (ASES) score were evaluated. At 12 months post operation, there was a significant improvement in these scores compared to preoperative values (P < 0.05), as detailed in Table 2....

Discussion

Subscapularis (SSC) injuries are identified in approximately 19% of shoulder arthroscopic surgeries, with Lafosse type I and II SSC injuries representing ~65% of these cases¹¹. These injuries frequently cause pain in the anterior shoulder area and result in weakened internal rotation, significantly impacting daily activities and work. Lafosse⁹ has categorized subscapularis muscle injuries into five types, from I to V. Research indicates that surgical treatment of Lafosse ty...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
16 G indwelling needle	Becton Dickinson
PDS = Polydioxanone Suture	Ethicon
Suture Anchors (4.5mm)	Rejoin Medical Technology		Used for suturing and fixing the subscapular muscle