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°; Figure 9). Functional scores improved significantly, with the following postoperative results: VAS score was 1, Simple Shoulder Test (SST) score was 11, Constant-Murley Shoulder Score was 91, and University of California Los Angeles (UCLA) Shoulder Score was 33.

The presented case exemplifies the efficacy of the simplified arthroscopic technique for upper third subscapularis tendon repair and cyst resection. The short operative time of 30 min and minimal blood loss of 10 mL reflect the minimally invasive nature of the procedure and its potential to reduce iatrogenic injuries. Postoperative MRI at 2 days confirms complete resection of the cyst near the subscapularis and satisfactory tension restoration of both the supraspinatus and subscapularis tendons, indicating successful anatomical correction. Functional outcomes at 9 months post-surgery demonstrate significant recovery of shoulder mobility and stability. These results highlight the ability of this simplified technique to address both structural and functional aspects of upper third subscapularis tear.

Figure 1: Pre-operative T2-weighted MRI scan. (A) Transverse sectional image of T2-weighted MRI shows right shoulder upper third subscapularis tear (Lafosse type II) and cyst formation near the tendon. (B) Coronal image of T2-weighted MRI shows right shoulder supraspinatus tendon tear (~ 3 cm). Please click here to view a larger version of this figure.

Figure 2: Establishment of standard arthroscopic portals and assessment of the subscapularis injury. In this case, place the patient in a standard left lateral decubitus position, with the right upper arm suspended at an abduction angle of 45° and anterior flexion of 15°. The standard posterior observation portal is created, and the anterior portal is created as an operation channel. (A) Intra-articular view of a right glenohumeral joint from the posterior viewing portal, showing the anterior part of the joint. (B) Intra-articular view of the upper third tear of the subscapularis tendon from the posterior viewing portal. In this figure, the orange arrow indicates the anterior operation portal. The black arrow indicates the subscapularis tendon. The green arrow indicates the humeral head. The blue arrow indicates the probe hook. The yellow arrow indicates the upper third tear of the subscapularis tendon. Please click here to view a larger version of this figure.

Figure 3: Rotator cuff interval cleaning, decortication of the footprint, and freshening. The posterior portal is used as a viewing portal, and the anterior portal is used as an operation portal. (A) Use a radiofrequency (blue arrow) to clean the subscapularis interval and expose the bone bed of the subscapularis footprint. (B) Use a shaver (yellow arrow) to decorticate the subscapularis footprint area and to freshen the remnant subscapularis. In this figure, the black arrow indicates the subscapularis tendon. The green arrow indicates the humeral head. The blue arrow indicates the radiofrequency. The yellow arrow indicates the shaver. Please click here to view a larger version of this figure.

Figure 4: Procedures of spinal needle with high-tensile suture percutaneously penetrating the subscapularis tendon, and suture passing. The posterior portal is used as a viewing portal, and the anterior portal is used as an operation portal. (A) A 12-gauge spinal needle with high-tensile suture. (B) Extra-articular view. (C-D) Insert the 12G spinal needle with high-tensile suture percutaneously in a vertical direction beneath the anterior portal, penetrating through the inferior portion of the subscapularis tear and capsule. (E-F) Pull out the intra-articular end of the suture using a probe hook or a suture grasper through the anterior approach. (G-J) Retrieve the spinal needle back outside the joint capsule and adjust the needle insertion angle, then reinsert the spinal needle again at the same percutaneous entry point, penetrating the superior portion of the subscapularis tear. Carefully withdraw the spinal needle and manage the suture with a probe to leave a small, looped segment passing through the superior tendon. (K-L) Introduce a suture grasper through the loop via the anterior portal, capture and pull out both free suture ends, and a T-shaped suture loop is constructed. In this figure, the black arrow indicates the subscapularis tendon. The green arrow indicates the humeral head. The blue arrow indicates the probe hook. The yellow arrow indicates the high-tensile suture. The orange arrow indicates the spinal needle. The pink arrow indicates the suture grasper. Please click here to view a larger version of this figure.

Figure 5: Schematic illustrations depicting the key procedures of percutaneous spinal needle suture passing and anchor implantation. (A-B) Insert the 12G spinal needle with high-tensile suture percutaneously in a vertical direction beneath the anterior portal, penetrating through the inferior portion of the subscapularis tear and capsule. (C-D) Pull out the intra-articular end of the suture using a suture grasper through the anterior approach. (E-F) Retrieve the spinal needle back outside the joint capsule and adjust the needle insertion angle, then reinsert the spinal needle again at the same percutaneous entry point, penetrating the superior portion of the subscapularis tear. Carefully withdraw the spinal needle and manage the suture with a probe to leave a small, looped segment passing through the superior tendon. (G-H) Introduce a suture grasper through the loop via the anterior portal, capture and pull out both free suture ends, and a T-shaped suture loop is constructed. (I-J) Place the single lateral row anchor, which is preloaded with both the free suture ends, into the footprint area of the torn subscapularis. The final construct comprises a T-shaped suture loop and a lateral row anchor without knots, compressing the subscapularis tendon against the insertion site. Please click here to view a larger version of this figure.

Figure 6: Single lateral row anchor implantation. The posterior portal is used as an observation portal, and the anterior portal is used as an operating portal. (A-B) Place the single lateral row anchor, which is preloaded with both the free suture ends, into the footprint area of the torn subscapularis. (C) The final construct comprises a T-shaped suture loop and a lateral row anchor without knots, compressing the subscapularis tendon against the insertion site. In this figure, the black arrow indicates the subscapularis tendon. The green arrow indicates the humeral head. The yellow arrow indicates the high-tensile suture. The pink arrow indicates the lateral row anchor. Please click here to view a larger version of this figure.

Figure 7: Confirmation of the satisfactory repair of the subscapularis tear. The posterior portal is used as an observation portal, and the anterior portal is used as an operating portal. Utilize a probe hook to confirm the satisfactory restoration of subscapularis tendon tension. In this figure, the black arrow indicates the subscapularis tendon. The green arrow indicates the humeral head. The blue arrow indicates the probe hook. Please click here to view a larger version of this figure.

Figure 8: Post-operative T2-weighted MRI scan. (A) Transverse sectional image of T2-weighted MRI shows that the cyst near the subscapularis is completely resected and a satisfactory restoration of subscapularis tendon tension. (B) Coronal image of T2-weighted MRI shows satisfactory repair of the right shoulder supraspinatus tendon tear. Please click here to view a larger version of this figure.

Figure 9: Right shoulder motion range restoration 9 months after surgery. (A-B) Active flexion: 0°-160°. (C) Active internal rotation: level L1. (D) Active external rotation: 0°-45°. Please click here to view a larger version of this figure.

Pearls	Pitfalls
1. When performing percutaneous spinal needle penetration, the ideal penetrating destination for first time is the lower part of subscapularis tear. The ideal penetrating destination for second time is the superior part of subscapularis tear.	1. The percutaneous spinal needle penetration sometimes is not easy to perform. It is necessary to restore the tendon tension at first using a suture grasper before penetrating.
2. Insertion position of the spinal needle outside the joint is generally below the anterior approach, mainly to make it easier to pass through the subscapularis tendon	2. When performing percutaneous spinal needle penetration, the skin insertion point should not be too low or inward to avoid damaging vessels and nerves.
3. Attention should be paid to avoid cutting the high tensile suture during spinal needle puncture, as the spinal needle is sharp.	3. The rotator cuff interval should be cleaned as much as possible, which will avoid suture management problems.
4. It is highly necessary to clean subscapularis interval before suturing, and to decorticate subscapularis footprint area and to freshen the remnant subscapularis before anchor implantation.
5. More T shape suture loops can be technically constructed as more suture ends can be loaded by the lateral row anchor.	4. During the continuous twice punctures process, the spinal needle should not be withdrawn from the skin tissue. Once the spinal needle is completely withdrawn from the skin, the continuous suturing is over.

Table 1: Pearls and pitfalls of the technique for arthroscopic repair of upper third subscapularis tears by percutaneous spinal needle suture passing with a T shape suture loop.

Advantages	Disadvantages
1. The key and challenging step of arthroscopic repair of upper third subscapularis tear is suture passing, especially for young surgeons, the shuttling technique with a curved suture hook or suture passer will cause iatrogenic injuries to subscapularis tendon. Our technique perfectly solves this problem and makes the challenging suture passing step easier.	1. Percutaneous spinal needle penetration has a learning curve, it requires additional learning and training, especially for the patients with very thick subcutaneous tissue or for patients with high tendon stiffness.
2. Spinal needle is smaller compared to traditional suturing device, which will reduce iatrogenic injuries. It can be tried and performed for multiple times and has higher error tolerance.	2. Percutaneous spinal needle penetration may cause damage to the tissue passing through.
3. Percutaneous spinal needle penetration has lower requirement for suturing angles. Spinal needle is easier to manually control and adjust the suturing angle or insertion point compared with rigid traditional suture devices.	3. Our technique may be not suitable for types of complex subscapularis tear before modification.
4. Percutaneous spinal needle penetration passing will avoid interference between the suturing device and grasper, save operation space for other arthroscopic instruments and make suture management easier with an additional invisible working channel.	4. A standard-length 12-gauge spinal needle might be insufficient for patients with very thick subcutaneous tissue or for patients with high tendon stiffness.
5. Our technique uses a lateral row anchor, it is knotless and easy to perform for beginners.
6. Our suture passing technique can be combined with other arthroscopic techniques to repair subscapularis tear.
7. Our technique uses standard and familiar viewing and working portals.
8. Our technique can be strategically modified and developed to repair other types of subscapularis tear
9. Our technique uses a continuous twice punctures during the suturing passing process.

Table 2: The advantages and disadvantages of the technique for arthroscopic repair of upper third subscapularis tears by percutaneous spinal needle suture passing with a T shape suture loop.

Potential problems	Solutions
1. Spinal needle with high-tensile suture may have difficulty in accurately penetrating the intended tendon location.	1. To ensure precise penetration, an instrument (e.g., a probe) inserted through the anterior working portal can be used to press against the tendon surface at the desired puncture point.
2. Spinal needle may damage vessels and nerves.	2. The skin insertion point should not be too low or inward to avoid damaging vessels and nerves.
3. Spinal needle may damage the suture.	3. To avoid damaging the suture by spinal needle tip, meticulous suture management, minimization of repeated penetration and gentle penetration are crucial.
4. The spinal needle might be insufficient for patients with very thick subcutaneous tissue or for patients with high tendon stiffness.	4.  For obesity, longer spinal needles (e.g., those used for deep nerve blocks) can be selected. For patients with high tendon stiffness, using a grasper inserted through an anterior portal to counter-traction and stabilize the tendon usually enables successful puncture.
5. The loop left after the second needle retrieval might be indistinct, difficult to visualize, or challenging to capture with the suture grasper due to tissue interposition.	5. Perform the second needle retrieval slowly to ensure a sufficiently large and identifiable loop is left behind with the aid of a probe.
6. Tangling may also occur when pulling out both suture ends through this loop.	6. Use a shaver to clear the interfering tissue within the operating field before the suture passing process. Perform meticulous suture management.
7. The bone quality at the anchor placement site (footprint) might be poor, compromising anchor fixation strength.	7. Ensure proper decoritcation of the footprint using a shaver or burr to achieve a bleeding bone bed before anchor placement, avoiding excessive bone removal. Select an anchor type with enhanced fixation properties (e.g., tapered threaded metal anchors or larger diameter bioabsorbable anchors) based on the intraoperative assessment of bone density. Always use the matching drill bit and follow the manufacturer's guidelines for drilling direction and depth.
8. The position or angle of anchor is unsatisfactory after implantation.	8.  Remove it, choose a new location with better bone stock for placement, or consider replacing it with larger diameter anchor or adding more anchors to achieve secure fixation.

Table 3: Potential problems and corresponding solutions associated with the presented technique.

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. Surgical restoration of this structure is critical for preserving glenohumeral joint biomechanics and functional integrity¹¹. Lafosse Type I and Type II subscapularis tears are the most commonly seen types of subscapularis injury. Conventional arthroscopic approaches often employ suture passers or hooks to repair these tears³. However, the substantial size and bulkiness of these instruments raise concerns, as they are not easy to manipulate and may inflict unintended damage to the tendon tissue, particularly when multiple punctures are required in the traditional suturing method. To overcome these limitations, we put forward a simplified technique for arthroscopic repair of upper third subscapularis tear, in which traditional suturing devices is substituted by a spinal needle, and traditional suturing and fixation method is evolved by a percutaneously continuous twice punctures process and a T shape suture loop with a knotless lateral row anchor, offering a more convenient and less invasive technique for subscapularis tendon repair.

Our simplified technique is best suited for upper third subscapularis tears (Lafosse type I and II) and offers several potential advantages during the challenging suture passing step. Firstly, compared with traditional suture devices, the spinal needle is much smaller in diameter. It will cause minimal iatrogenic injuries, and the penetration can be tried and performed multiple times; it has a higher error tolerance feature, particularly advantageous for novice surgeons. Secondly, the percutaneous needle allows more flexible control over suturing angle and entry point compared to rigid conventional devices. Thirdly, this approach reduces interference between instruments in the confined anterior working space, facilitating suture management. Fourthly, we compress the subscapularis tendon against the insertion site with a single lateral row anchor; it is knotless and easy to perform for beginners. Fifthly, the suture passing technique can be combined with other arthroscopic techniques to repair a subscapularis tear. Lastly, the technique can be strategically modified and developed to repair other types of subscapularis tears.

Despite these benefits, several considerations should be noted. Firstly, even though the simplified technique has minimal iatrogenic injuries, higher error tolerance, and is easier to manually perform, novice surgeons need additional procedural and anatomical training to have a better understanding of percutaneous needle positioning and a profound understanding of anatomy, especially for patients with very thick subcutaneous tissue or for patients with high tendon stiffness. Otherwise, there is a risk of causing damage to the tissue passing through, including vessels and nerve tissue. Secondly, the construct comprising a T-shaped suture loop and a lateral row anchor is suitable for the upper third subscapularis injuries (Lafosse Type I and Type II), and may not be suitable for other types of complex subscapularis tears. Thirdly, a standard-length 12G spinal needle might be insufficient for patients with very thick subcutaneous tissue or for patients with high tendon stiffness.

During the critical steps of this technique, several problems may be encountered. The following provides solutions and advice for addressing potential problems during suture passing, loop formation, and anchor placement. Firstly, potential problems during suture passage: difficulty may arise in accurately penetrating the tendon, or there may be a risk of neurovascular injury, suture damage, or inadequate needle length or strength for patients with very thick subcutaneous tissue or for patients with high tendon stiffness. Solutions: To ensure precise penetration, an instrument (e.g., a probe) inserted through the anterior working portal can be used to stabilize and localize the desired puncture point. The skin insertion point should not be too low or inward to avoid damaging vessels and nerves. To avoid damaging the suture by the spinal needle tip, meticulous suture handling, gentle needle manipulation, and minimization of repeated penetration are crucial. For obesity, longer spinal needles (e.g., those used for deep nerve blocks) can be selected. For patients with high tendon stiffness, for stiff tendons, counter-traction with a grasper via the anterior portal can facilitate penetration. Secondly, T-Loop Formation: The suture loop may be poorly defined, difficult to visualize, or challenging to capture due to tissue interference; tangling may also occur when pulling out both suture ends through this loop. Solutions: Withdraw the needle slowly to leave a clear, sufficiently large loop with the aid of a probe. Use a shaver to clear the interfering tissue within the operating field before the suture passing process. Perform meticulous suture management. Thirdly, potential problems during anchor placement: Poor bone quality may compromise anchor fixation, or the anchor may be malpositioned. Solutions: Ensure proper decoritcation of the footprint using a shaver or burr to achieve a bleeding bone bed before anchor placement, avoiding excessive bone removal. Select an anchor type with enhanced fixation properties (e.g., tapered threaded metal anchors or larger diameter bioabsorbable anchors) based on the intraoperative assessment of bone density. Always use the matching drill bit and follow the manufacturer's guidelines for drilling direction and depth. If anchor loosening is detected, remove it, choose a new location with better bone stock for placement, or consider adding more anchors to achieve secure fixation. It is not recommended to remove the original anchor and re-implant it in the same tunnel.

The pearls and pitfalls of our technique are shown in Table 1, and the advantages and disadvantages are shown in Table 2. The potential problems may be encountered during the critical steps of this technique, and the solutions for these problems are shown in Table 3. Based on this case, our technique has shown a promising application potential in clinical situations, which is simple, efficient, safe, and cost-effective.

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