Simplified Technique for Arthroscopic Repair of Upper Third Subscapularis Tear by Percutaneous Spinal Needle Suture Passing with a T Shape Loop

Summary

We present a simplified surgical technique combining percutaneous spinal needle suturing and a T-shaped suture loop construction for arthroscopic treatment of upper third subscapularis tears. This technique demonstrates dual clinical advantages, reducing operational complexity for surgeons and imposing less damage on patients, showing a promising application potential in clinical situations.

Abstract

The subscapularis tear is a commonly seen shoulder injury requiring arthroscopic repair. This article describes a simplified arthroscopic technique for repairing the upper third subscapularis injury. The procedure includes the steps of subscapularis tear identification, decortication of the footprint and freshening, percutaneous suture passage using a spinal needle, construction of a T-shaped suture loop, and placement of a single lateral row anchor. This technique replaces traditional suture-passing devices and traction sutures with a 12G spinal needle loaded with a high-tensile suture. Its novelty lies in the combination of a percutaneous spinal needle for suture passage and the construction of a T-shaped suture loop. The final construct, securing the tendon with the T-loop and a single lateral row anchor, provides robust compression at the insertion site. Our simplified technique offers distinct advantages of easier suturing passing operation, more convenient suture management, more flexible insertion site selection, less invasive to patients, and higher error tolerance for iatrogenic damage, and it should be a promising technique in clinical situations.

Introduction

The subscapularis, located in the anterior aspect of the shoulder, is the largest and most powerful rotator cuff muscle. It plays a critical role in proper shoulder function¹. Beyond its primary function as an internal rotator, the subscapularis also acts to pull the humeral head posteriorly on the glenoid and is an important dynamic and static anterior stabilizer of the glenohumeral joint. Studies have indicated that subscapularis injuries constitute approximately 30% to 50% of all rotator cuff injuries². The Lafosse classification system categorizes intraoperative findings of subscapularis tear into five types: A Type I lesion is defined as a partial lesion of the superior one-third. Type II is a complete lesion of the superior one-third. Type III is a complete lesion of the superior two-thirds. Type IV is a complete lesion of the tendon, but head-centered and fatty degeneration is classified as less than or equal to stage 3. Type V is a complete lesion of the tendon, but eccentric head with coracoid impingement and fatty degeneration, classified as more than or equal to stage 3³. Recent clinical focus has intensified on the upper third subscapularis injuries (Lafosse Type I and Type II), which are the most frequently observed types of subscapularis injuries⁴.

Contemporary management of upper third subscapularis tear could be approached both with arthroscopic technique and open surgery. With the advancements in arthroscopic techniques and the development of instruments over the past decades, arthroscopic management of subscapularis tears yielded comparable or even better outcomes compared with open surgery, achieving effective structural restoration, pain reduction, functional recovery, and high patient satisfaction⁵. However, the traditional arthroscopic procedures for subscapularis tears can be challenging technically, even for expert surgeons, due to limited visualization, the narrow working space of the anterior shoulder, difficulties in controlling conventional repairing devices, the need for multiple punctures, and the complexity of passing traction sutures and tying knots. Recently, many arthroscopic techniques have been proposed and modified to repair subscapularis tears in a convenient and effective manner, but the use of traditional devices, such as suture passers and hooks, along with conventional suturing methods, are still quite common^6,7,8. Except for difficulties of operation, traditional suturing procedures and devices can potentially cause additional iatrogenic injury to tendon tissue because of their large diameter and size, especially when multiple tries of puncture are required in the narrow working space for young surgeons.

In this article, we propose a simplified technique for arthroscopic repair of upper third subscapularis tears, integrating two key techniques: percutaneous spinal needle suture passing and the T-shaped suture loop knotless technique, which addresses the shortcomings of reported techniques. Our technique possesses several strengths: easier suturing passing operation in the limited working space of the anterior shoulder, more convenient suture management, more flexible insertion site selection, less iatrogenic injury to the tendon, higher error tolerance for iatrogenic damage, and use of familiar viewing and working portals. It should be a promising technique in clinical situations.

Case presentation: A 51-year-old male patient presented with pain and discomfort in the right shoulder under load for 8 months. Physical therapy and drug therapy were administered during this period, but no significant relief of symptoms or functional improvement was achieved.

Diagnosis, Assessment, and Plan: The MRI of the right shoulder showed a tear of the supraspinatus tendon (~ 3 cm), an upper third subscapularis tear (Lafosse type II), and cyst formation near the tendon (Figure 1). Physical examination indicated restriction of right shoulder motion with the following measurements (active flexion: 120°, active abduction: 160°, active external rotation: 35°, passive flexion: 160°, passive abduction: 170°, and passive external rotation: 40°). The special tests: Jobe Test (+), Bear Hug Test (+), Napoleon Test (+) were done. The patient's preoperative average VAS score was 6, the Simple Shoulder Test (SST) score was 6, the Constant-Murley Shoulder Score was 62, and the University of California, Los Angeles (UCLA) Shoulder Score was 18. His past medical history demonstrated arterial hypertension. Arthroscopic surgery was planned, and a diagnosis of upper third subscapularis tear was made by physical examination and MRI images. The patient was tested to be medically fit for surgery and to accept arthroscopy surgery.

Protocol

The procedure described here was conducted in compliance with the guidelines set out by the Ethics Committee of Union Hospital, Tongji Medical College, Huazhong University of Science and Technology. The patient provided informed consent.

1. Pre-operative preparations

1. The patient was prepared for surgery, and hair removal was done at the site. The patient was asked to abstain from eating for 8 h and drinking for 2 h before surgery. Hypertension was kept under control.
2. Standard arthroscopic equipment and the following instruments were prepared: Arm traction frame for shoulder joint surgery, saltwater rack, 30° arthroscope, probe hook, 12-gauge spinal needle, suture grasper, and drill awl.
3. Sutures and all necessary consumables were made available (Table of Materials).

2. Surgical preparation

1. Anesthetic operative risk was assessed by providing a grade according to the American Society of Anesthesiologists' (ASA) classification of Physical Health.
2. One large bore (14 G or 16 G) intravenous cannula was placed in a peripheral vein.
3. Electrocardiograms, blood pressure, capnography, pulse oximetry, urinary volumes, and body temperature were monitored throughout.
4. General anesthesia was administered by endotracheal intubation. In this case, inhalation and intravenous anesthesia were combined.
5. The systolic blood pressure was controlled between 95-105 mmHg during the procedure.
6. During surgery, blood gas analysis was done to verify blood gases and pH. At the end of the procedure, reverse anesthesia and removal of the endotracheal tube were done.
7. Operation room setup
   1. The arm traction frame and saltwater rack were placed on the patient's leg side. After anesthesia, the patient was placed in a standard left lateral decubitus position. A 5 kg weight was suspended from the arm, with the right upper arm suspended at an abduction angle of 45° and anterior flexion of 15°.
   2. A broad-spectrum antibiotic administered intravenously 30 min before surgery. An injection of norepinephrine (1 mg) was done into a 3 L saline bag to control intraoperative bleeding.
   3. The main surgeon stood behind the patient. The first assistant stood at the patient's bedside. He or she helps to place the anchor. The scrub nurse stood at the right side of the main surgeon.

3. Surgical technique

1. Establishment of standard arthroscopic portals
   1. After routine disinfection and draping, the standard posterior viewing portal, approximately 1-2 cm medial and inferior to the posterolateral acromial border, was established.
   2. The anterior operation portal was created using an outside-in technique, which is positioned just superior to the subscapularis tendon. Proper placement of the anterior operation portal was confirmed with a spinal needle.
2. Assessment of the subscapularis injury
   1. The 30° arthroscope was inserted through the standard posterior portal to observe the glenohumeral joint (Figure 2A).
   2. A probe hook was used to confirm the presence of a complete tear in the upper third of the subscapularis tendon (Figure 2B).
3. Rotator cuff interval cleaning, decortication of footprint, and freshening
   1. After establishing the standard arthroscopic portals and confirming the presence of an upper third subscapularis tear, the radiofrequency device (ablation mode: level 7, coagulation mode: level 3) was used to clean the subscapularis interval and expose the bone bed of the subscapularis footprint on the lesser tuberosity (Figure 3A).
   2. A shaver (motion mode: reciprocating motion mode, 1700 rpm) was used to decorticate the subscapularis footprint area and to freshen the remnant subscapularis (Figure 3B).
      NOTE: When using a radiofrequency or shaver device, the operator should always operate within the field of view and in known anatomical areas. Especially with caution required in the area medial to the coracoid process.
4. Spinal needle preparation, and the processes of percutaneous spinal needle suture passing through the subscapularis tendon
   1. The posterior portal was used as an observation portal, and the anterior portal was used as an operating portal. A 12G spinal needle was prepared and preloaded with a high-tensile suture (#2 Violet 1/2 Circle, Taper Point Needle, 22 mm; Figure 4A).
   2. The spinal needle was inserted percutaneously in a vertical direction beneath the anterior portal to penetrate the inferior portion of the subscapularis tear. The intra-articular end of the suture was grasped under arthroscopic visualization and withdrawn through the anterior portal using a suture grasper (Figure 4B-G, Figure 5A-D).
   3. The spinal needle was retrieved back outside the joint capsule, the needle insertion angle was adjusted, and the spinal needle was reinserted at the same percutaneous entry point, penetrating the superior portion of the subscapularis tear ( Figure 4H-I, Figure 5E).
   4. The spinal needle was carefully withdrawn, and the suture was managed with a probe to leave a small, looped segment passing through the superior tendon. At this moment, both free ends of the suture were outside the joint (Figure 4J, Figure 5F).
   5. A suture grasper was introduced through the loop through the anterior portal, captured, and both free suture ends were pulled out, thereby constructing a T-shaped suture configuration spanning the superior and inferior portions of the tear (Figure 4K-L, Figure 5G-H).
      NOTE: When performing percutaneous spinal needle penetration, the skin insertion point should not be too low or inward to avoid damaging vessels and nerves. Due to the sharp needle tip, take special care to avoid damaging the suture, which could lead to intraoperative or postoperative suture failure.
5. Single lateral row anchor implantation
   1. The drill awl was used to create a bone tunnel matching the anchor's depth and diameter within the subscapularis footprint on the lesser tuberosity. The drilling angle of the drill awl should be at a 45° angle within the footprint area. If the anchor position or angle is found to be unsatisfactory after implantation, it is not recommended to remove the original anchor and re-implant it in the same tunnel; a new implantation site should be selected.
   2. The single lateral row anchor was placed, which is preloaded with both the free suture ends, into the footprint area of the torn subscapularis until it is fully seated (Figure 5I, Figure 6A-B).
   3. The final construct comprises a T-shaped suture loop and a knotless lateral row anchor, compressing the subscapularis tendon against the insertion site (Figure 5J, Figure 6C). During the anchor implantation process, tighten the sutures to firmly compress the subscapularis tendon against the footprint area, also manage the sutures to prevent twisting, tangling, or damage.
6. Confirming the satisfactory repair of the subscapularis tear
   1. With the standard posterior observation portal and the anterior observation portal, utilize a probe hook to confirm the firm compression of the subscapularis tendon against the footprint area and the satisfactory restoration of subscapularis tendon tension (Figure 7).

4. Completion of surgery

1. A drainage tube was placed close to the wound, and a sterile dressing was applied. The shoulder was protected with a sling immobilizer using an abduction pillow.
2. Waste was disposed of in appropriately labeled containers. Sharps must be placed directly into the designated sharps container and must not be left on any surface for others to handle.
   NOTE: Medical waste is managed in compliance with local, provincial, and national regulations of the People's Republic of China. This guide is based on widely accepted WHO guidelines for the safe handling of medical waste, specifying the classification, collection, storage, transportation, and disposal.

5. Postoperative rehabilitation

1. Rehabilitation after rotator cuff surgery is a prolonged but essential process, often taking 6-12 months for a full return to activity. The shoulder was immobilized for 6 weeks using a sling immobilizer with an abduction pillow.
2. At 2 weeks after surgery, passive and assisted active exercises were initiated for forward flexion and external rotation, avoiding provocation of pain. After 6 weeks, patients progressed to active motion, aiming to restore the full active range of motion and improve scapular stability. At 12 weeks, strengthening exercises for the rotator cuff and scapular stabilizers were introduced. Full return to sports and heavy labor was permitted after 6 months, based on individual functional recovery.

Results

The operation time was 30 min with an estimated blood loss of 10 mL. At 2 days after surgery, MRI showed the cyst near the subscapularis was completely resected and a satisfactory tension restoration of both the subscapularis and supraspinatus tendons (Figure 8). At 9 months after surgery, the patient had a satisfactory motion range restoration (active flexion:0-160°, active internal rotation: L1 level, active external rotation:0-45°; Fig...

Discussion

Subscapularis tear is a common form of rotator cuff injury and frequently necessitates arthroscopic repair. Historically, the subscapularis was first ignored as the forgotten tendon of the shoulder joint^9,10. Over the last two decades, the importance of the subscapularis muscle-tendon unit has gained recognition. It acts as the main internal rotator of the shoulder and is the single anterior stabilizer of the transversal force couple of the glenohumeral joint. Su...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
high-tensile suture (Orthocord Suture)	DePuy Mitek		high-tensile suture (#2 Violet W/ MO-7 1/2 Circle, Taper Point Needle, 22 mm)
lateral row anchor	Star Sports Medicine	AK7-D1	lateral row anchor (Tapscrew PK)
radiofrequency	BONSS	MC405
shaver	Star Sports Medicine	BB01SS