Arthroscopic Release of Frozen Shoulder - An Overview

Introduction

A frozen shoulder is a frequent condition in orthopedic practice. It affects about two to five percent of individuals, with increased women predilection between the ages 40 and 60. The cause of frozen shoulder is unknown (also called idiopathic primary frozen shoulder syndrome, PFSS). However, diabetic patients are more prone to developing a frozen shoulder. Frozen shoulder is also called adhesive capsulitis due to the formation of thick bands of tissue (adhesions). It causes shoulder pain, stiffness, and limited movement. One must note that no significant findings in the patient’s history, clinical examination, or radiographic studies explain the limited motion or pain.

What Is Arthroscopic Release of Frozen Shoulder?

The shoulder joint is surrounded by a connective tissue called the shoulder capsule. In patients with frozen shoulders, several conservative measures (physical therapy, anti-inflammatory drugs, and steroid injections) are effective for pain control. However, patients with chronic (long-term) shoulder stiffness require arthroscopic capsular release (ACR). In this technique, the joint is viewed through a tube attached to a video camera. Subsequently, the images are seen on an external monitor. Studies reveal that ACT provides rapid, complete, and long-lasting improvement of shoulder pain and function. Further, the results are faster than any other treatment modality.

What Are the Indications of Arthroscopic Release of Frozen Shoulder?

The indications to proceed with ACR for frozen shoulder are:

1. Failure of Rehabilitation Program: Rehabilitation for frozen shoulder includes conservative treatments such as nonsteroidal anti-inflammatory drugs (NSAIDs, pain-reducing drugs), glucocorticoids (oral or injectables), and physical therapy. ACR is advised if the rehabilitation program takes more than six months without any outcome.

2. Failure After More Than Three Steroid Injections Within Six Months Interval: The Cortisone (a steroid) injection is used to reduce pain and inflammation in the shoulder. It is beneficial in the early stages, where shoulder pain is more than stiffness. However, ACR is employed if the patient does not get relief even after more than three injections within six months.

3. Failure of Less Invasive Treatments: Less invasive modalities include hydrodistension (HD) or MUA. HD involves injecting a large volume of saline, steroid, and local anesthetic (LA) into the shoulder joint under imaging. HD can provide short-term benefits regarding pain, movement, and joint function. On the other hand, MUA involves the forced movement of the shoulder (also called passive tearing) under general anesthesia (GA). As a result, it will cause tearing of the joint capsule and a decrease in tightness. Studies reveal that it gives the same results as ACR. But, performing MUA alone can lead to humeral (humerus is the upper arm bone) fracture. Hence, ACR is done in combination with MUA if these treatments fail.

4. Diabetic Patients: Steroids are contraindicated in diabetic patients with PFSS (as they raise blood sugar). Hence, surgical treatments such as ACR are explored in such patients.

What Is the Procedure for Arthroscopic Capsular Release?

Due to complications of MUA and arthroscopic advances, ACR is the most frequently used surgical intervention that gives long-term improvements in symptoms.

1. Before regional anesthesia (only the shoulder becomes numb), the surgeon performs a presurgical evaluation of the range of motion (ROM) of the joint in a conscious patient.

2. After the insertion of the arthroscope, the surgeon performs a careful assessment of the joint and the surrounding injuries. Diagnostic arthroscopy identifies synchronous joint injuries.

3. At this stage, a radiofrequency device designed for clotting, cutting, and tissue vaporization is used. Next, the surgeon releases the capsular and ligament (a tissue connecting two bones) adhesions. The surgeon also performs careful shoulder manipulation.

4. Care is required regarding the axillary nerve (pertaining to the armpit) located underneath the capsule. Hence, the surgeon must be aware of the precise location of the axillary nerve to avoid injury.

5. Oral Cortisone medication is given to the patient after the surgery for one month. Further, the surgeon performs a postsurgical assessment of the ROM. The patient gains a full ROM immediately after the procedure. However, one must note that the postsurgical rehabilitation program is started immediately for better recovery.

The required optimal degree of release is unclear. Further, the most appropriate timing to perform ACR is also under debate. Although surgeons wait for the failure of the conservative course, patients' wishes may force them for an earlier surgical decision.

What Are the Benefits of Arthroscopic Capsular Release?

ACR carries several advantages over other treatment modalities.

1. It provides accurate and controlled release of the capsule and ligaments. Therefore, it is safer as it reduces the risk of traumatic complications such as bone fractures after forceful shoulder manipulation.

2. A radiofrequency device performs the release of the capsule and the involved structures. The advantage is delayed healing, which prevents adhesion formation. Moreover, ACR reduces soft-tissue trauma and bleeding within the joint, preventing further adhesions.

3. The technique is straightforward, and an oral steroid post-surgery decreases pain and allows for pleasant early rehabilitation. Further, the long-term outcome is favorable.

4. The procedure is performed under regional anesthesia (the patient is awake), which boosts the patient's confidence and compliance.

5. In patients with refractory PFSS, ACR is the preferred technique that expedites recovery. Also, diabetic patients benefit from the same.

6. ACR also allows for visual confirmation of the diagnosis and treatment of concomitant joint diseases.

ACR includes a few steps (regional anesthesia, capsular release, splitting of ligaments, resection of adhesions, and shoulder manipulation) followed by an oral Cortisone plan and a rehabilitation program. These steps play a pivotal role in patients with PFSS and recalcitrant symptoms or in those who want an expedited recovery. Although MUA improves shoulder elevation and abduction (motion away from the midline of the body), rotation is limited because surgeons are concerned about forceful rotary movements. Bone fractures, rotator cuff injury (rotator cuff in the shoulder helps lift the arm), and labral detachments (a labrum is a soft tissue rim around the shoulder to make it stable) affect MUA's results. Therefore, orthopedics favor ACR over MUA.

Conclusion

A frozen shoulder improves over time, although full recovery may take years. Physical therapy and medications are the first-line treatment for a frozen shoulder. However, some patients do not get relief from the same. Hence, more invasive procedures, such as arthroscopic release, are advocated for patients who do not respond to conservative treatments (refractory frozen shoulder). One must note that ACR is a reliable treatment method with a low complication rate. It provides improvements in shoulder motion and functions unrelated to the surgery timing.