An Improved Continuous Suturing Technique Using a Suture Hook for Subscapularis Repair

Summary

Subscapularis tendon tears remain challenging in orthopedic surgery. Conventional sutures cause uneven load distribution, while advanced methods improve outcomes but complicate procedures. A unique hybrid technique using a sewing machine-style suture with a single-portal approach is introduced here, offering stronger fixation, reduced trauma, enhanced outcomes, and improved convenience for effective subscapularis repair.

Abstract

Subscapularis tendon injuries often pose substantial challenges in arthroscopic repair, with traditional techniques frequently limited by prolonged surgical time, uneven tension distribution, and increased complication risk. Although advanced suture-passing and suturing methods can improve biomechanical outcomes, they generally require complex instrumentation. A hybrid approach is presented here that integrates a continuous sewing machine-like suture technique with a single-portal spinal needle method for subscapularis repair. The sewing machine-like technique facilitates efficient loop formation, which ensures even tension distribution and allows precise suture placement through flexible puncture points. The single-portal approach minimizes invasiveness, reduces tissue trauma, and streamlines the surgical process. Collectively, these techniques enhance the biomechanical strength, shorten operative time, and align with the principles of modern minimally invasive surgery. This improved and innovative strategy represents a promising alternative to conventional methods, with the potential to improve clinical outcomes. Further clinical validation and long-term follow-up are required to confirm its efficacy.

Introduction

Rotator cuff injuries involving the subscapularis tendon pose significant challenges due to the tendon's unique anatomical position, limited surgical exposure, and critical role in maintaining shoulder stability and function¹. These tears often cause severe pain, functional impairment, and reduced quality of life². Current arthroscopic repair techniques aim to address these challenges but are limited by complex instrumentation, lengthy operative times, and suboptimal biomechanical outcomes. Despite advancements in suture technology and minimally invasive methods, repair of subscapularis tendon tears remains technically demanding.

Traditional suture methods, including interrupted and mattress techniques, have been widely used in arthroscopic rotator cuff repair. While effective in achieving basic tendon fixation, these methods often require multiple portals and extensive tissue manipulation, resulting in prolonged operative times and higher complication risks. Burkhart et al. reported the complexity of dual-portal approaches, highlighting the increased risk of soft tissue damage and longer recovery times associated with these techniques³. Anchor-based techniques, commonly used for their fixation strength, also have limitations such as anchor failure and inability to achieve uniform tension across the tendon, potentially leading to suboptimal healing.

Advanced methods such as the transosseous equivalent suture-bridge technique provide improved footprint coverage and enhanced biomechanical stability⁴. However, this approach often increases technical complexity and risks of overtightening, which may compromise vascular supply and healing potential. These challenges highlight the need for innovative strategies that combine precision, efficiency, and minimal invasiveness.

Prior research introduced the continuous sewing machine-like suture technique, inspired by the mechanical precision and efficiency of sewing machines⁵. This method enables continuous suturing with a loop structure, ensuring even tension distribution and reducing knot-related failures. The technique simplifies the suturing process, improves biomechanical stability, and significantly decreases surgical time and costs. Its application in meniscal repair has demonstrated potential for enhancing clinical outcomes, suggesting utility in rotator cuff repair as well.

Studies on the single-portal approach for subscapularis repair utilizing a spinal needle as a suture passer have highlighted advantages in reducing invasiveness and improving surgical precision⁶. By employing a single anterior portal for visualization and instrumentation, this technique minimizes soft tissue trauma, lowers the risk of neurovascular complications, and streamlines the procedure. Such an approach is particularly advantageous for addressing subscapularis tears, where surgical space is inherently limited.

Although each of these techniques has demonstrated considerable benefits independently, their integration offers a promising solution to the challenges of subscapularis tendon repair. The sewing machine-like suture technique provides robust, efficient, and precise suture placement, while the single-portal approach emphasizes minimal invasiveness and surgical simplicity. Combined, these methodologies create a synergistic effect that enhances biomechanical strength, shortens operative time, and reduces postoperative complications.

Building on previous findings, this study develops and evaluates a surgical protocol that combines the continuous sewing machine-like suture technique with the single-portal approach. The protocol is designed to enhance surgical efficiency, minimize invasiveness, and achieve superior biomechanical outcomes compared with traditional methods. By addressing current limitations in subscapularis repair, this approach aims to establish a new standard for the treatment of subscapularis injuries.

Protocol

All procedures involving human participants were conducted in accordance with the ethical standards of the institutional and/or national research committee and with the principles outlined in the Declaration of Helsinki. Institutional Review Board (IRB) approval was obtained prior to initiation of the study, and written informed consent was obtained from all participants before enrollment. Patient confidentiality and privacy were strictly maintained throughout the study.

1. Preoperative preparation

1. MRI examination: Perform an MRI of the affected shoulder preoperatively to assess the extent of rotator cuff damage.
2. Additional imaging: Perform a CT scan and X-ray of the shoulder joint to identify microfractures, dislocations, or other pathological changes.
3. Patient medical history: Evaluate age and underlying conditions, such as hypertension or diabetes, during the preoperative assessment to guide postoperative rehabilitation planning and expected outcomes.

2. Anesthesia

1. Perform the procedure under general anesthesia combined with a brachial plexus block (interscalene block) (following institutionally approved protocols).
2. Use general anesthesia as the preferred choice, unless contraindicated, since it provides better muscle relaxation during the procedure.

3. Medication and intraoperative measures

1. Antibiotic prophylaxis: Administer prophylactic antibiotics, such as cefazolin sodium (1 g), 30 min before surgery to prevent infection.
2. Nutritional support: Provide nutritional support preoperatively if necessary.
3. Arterial and central venous lines: Assess the need for arterial and central venous line placement based on condition and expected surgical duration.

4. Patient positioning

1. Position the patient in the lateral decubitus position with the affected arm in traction.
2. Hang a 5 kg weight on the arm and place the shoulder at 50° abduction and 15° forward flexion.

5. Surgical portal setup

1. Disinfect and drape the surgical area. Establish a posterior portal for observation and insert a 30° arthroscope to visualize the glenohumeral joint.
2. Create an anterior portal for the operative approach. Use a radiofrequency (RF) device through the anterior portal to clean the rotator cuff interval and clearly expose the torn tendon.

6. Surgical procedure

1. Tear assessment
   1. Use the posterior portal to evaluate the extent of the rotator cuff tear. Freshen the bone bed at the tendon attachment site with a bone planer to prepare a healthy bone surface and remove damaged tissue.
2. Suture hook preparation and first set of continuous sutures
   1. Refer to the representative results for an illustration of the suture process. Prepare the suture hook, load high-strength suture through the hook's eye, and leave a portion of the suture at the hook's head to form a loop structure. Insert the suture hook through the anterior portal and guide it to the tear site. Perform the first pass through the tendon tissue.
   2. Introduce a clamp through the anterior portal to grasp the suture loop, then pull the free end of the suture out of the hook. Create a small lateral incision if necessary to facilitate clamp operation. Withdraw the suture hook slowly while maintaining the suture inside the hook, and perform a second pass through the tendon.
   3. Hold the suture loop with the clamp, then pass the free end of the suture through the loop. Continue suturing as needed, ensuring multiple passes to stabilize the tendon with an enhanced suture structure.
3. Second set of continuous sutures or additional sutures
   1. Place a second set of sutures to achieve parachute fixation of the rotator cuff. Select an appropriate location for the second set and repeat the same process as the first set, adjusting the number of passes based on tissue condition and repair requirements.
4. Suture fixation
   1. Gather all free ends of the sutures and fix them with anchor devices. Place anchors before completing the sutures and tie knots after sutures are placed to ensure secure fixation.
5. Final arthroscopic evaluation
   1. Use the arthroscope to confirm the quality of the repair. Verify that sutures are evenly distributed, knots are secure, and there is no suture slippage or interference.

7. Postoperative care, rehabilitation recommendations, and follow-up

1. Skin closure: Close skin incisions in layers and dress the surgical area with pressure bandages.
2. Rehabilitation: Design the postoperative rehabilitation plan according to the condition. Instruct wearing of a shoulder immobilizer for 4-6 weeks. Progress rehabilitation gradually: begin with fist clenching, wrist flexion and extension, and elbow flexion and extension, followed by progressive shoulder joint functional exercises to restore function.
3. Follow-up: Schedule a follow-up visit one month postoperatively for clinical examination and functional assessment. Perform an MRI to assess rotator cuff healing.

Results

Preoperative imaging and diagnosis

A preoperative MRI examination of the patient revealed a tear in the superior 1/3 of the subscapular tendon and a tear in the supraspinatus tendon. These findings were critical in guiding the surgical approach and determining the extent of the tendon damage (Figure 1).

Arthroscopi...

Discussion

The repair of subscapularis tendon tears remains a technically challenging endeavor due to the tendon's deep-seated anatomical position and critical biomechanical role. While traditional suture techniques provide satisfactory outcomes in many cases, their limitations highlight the need for innovation in this domain. The improved technique, combining the continuous sewing machine-like suture method with a single-portal approach, offers a promising alternative that addresses some of the key limitations associated with ...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
30° Arthroscope	Arthrex	https://www.arthrex.com	Used for arthroscopic visualization of the shoulder joint
Anchor devices	Arthrex	https://www.arthrex.com	Anchors for securing sutures to bone
CT scanner	Siemens	https://www.siemens-healthineers.com	Computed tomography scanner for preoperative bone quality assessment
High-strength sutures (e.g., FiberWire, Ethibond)	Arthrex	https://www.arthrex.com	High-strength sutures for tendon fixation
MRI scanner	Siemens	https://www.siemens-healthineers.com/magnetic-resonance-imaging	Magnetic resonance imaging scanner for preoperative and follow-up evaluation
Radiofrequency (RF) device	Arthrex	https://www.arthrex.com	Used for clearing the rotator cuff interval and soft tissue debridement
Shoulder traction system	Smith & Nephew	https://www.smith-nephew.com	Used for patient positioning and shoulder traction during surgery
Surgical clamps	Medtronic	https://www.medtronic.com/	Used for clamping and assisting with suture handling
Suture hook	Arthrex	https://www.arthrex.com	Used for continuous suture passing during tendon repair