Copyright 2010 American Academy of Orthopaedic Surgeons
Thermal Capsular Shrinkage

A surgical technique called thermal capsular shrinkage (also known as thermal capsulorrhaphy) was recently developed to treat several types of shoulder instability. The procedure uses heat to shrink and tighten the shoulder capsule, which is the connective tissue around the shoulder joint that helps to keep it stable.

Thermal capsular shrinkage was developed as a less invasive way to treat a shoulder that is loose or frequently dislocates. Early short-term results with thermal capsulorrhaphy were encouraging, and the procedure rapidly gained in popularity. However, more recent results with patients over a longer follow-up period have shown a much higher failure rate than was first seen. Also, more complications have been reported. As a result, doctors are performing thermal capsular shrinkage less frequently.

Candidates for Surgery
The shoulder capsule is made up of connective tissue and ligaments that surround the shoulder and connect the upper arm bone to the shoulder blade.

Your doctor may recommend thermal capsular shrinkage if you have chronic shoulder instability. This means that injury or overuse have caused the soft tissues of your shoulder to stretch or tear so much that they no longer provide the necessary support. You may have a feeling of "looseness" in your shoulder or your shoulder may "pop out" with some activities. Pain and weakness may interfere with your daily activities, such as work, sports, or sleep.

Your orthopaedic surgeon will discuss treatment options that are best for you, based on the cause of your shoulder instability and how loose it is.

Most Successful Candidates for Thermal Capsular Shrinkage

The best candidates for thermal capsular shrinkage are people who have not had prior shoulder surgery, and have not had multiple shoulder dislocations.

Studies show that thermal capsular shrinkage is more successful when it is used along with other procedures to fix the shoulder, such as a repair of a torn labrum (the labrum is a ring of cartilage that circles the socket bone to hold the shoulder stable). Thermal capsular shrinkage is less successful when it is used as a stand alone procedure.

Less Successful Candidates for Thermal Capsular Shrinkage

Thermal capsular shrinkage is not appropriate for everyone. For example, if your shoulder instability is a result of a traumatic injury, the tissues may be so damaged that they require surgery to reattach them to the bones.

In addition, studies show that patients with multidirectional instability are not good candidates for thermal capsular shrinkage. Multidirectional instability is a condition that leads to a shoulder that is loose or dislocates in all directions. It is usually not caused by a serious injury.

Planning for Surgery

Doctor Evaluation

In addition to discussing your symptoms and medical history, your surgeon will perform a thorough physical examination to determine if you are a good candidate for the procedure.

X-rays of your shoulder will be taken to make sure there are no abnormalities of the bone. Your surgeon may also order a magnetic resonance imaging (MRI) scan to look for tearing of the soft issues of the shoulder, like the labrum.

If you are generally healthy, your procedure will most likely be performed as an outpatient. This means you will not need to stay overnight at the hospital.

The Day of Surgery

The hospital or surgery center will contact you ahead of time to provide specific details about your procedure. Make sure to follow the instructions on when to arrive and especially on when to stop eating or drinking prior to your procedure.

Before the operation, you will also be evaluated by a member of the anesthesia team. Thermal capsular shrinkage can be done with general anesthesia (where you are put to sleep) or regional anesthesia (where you are given a medicine to numb the area around your shoulder). Your orthopaedic surgeon and the anesthesiologist will talk to you about the best method for you.

Surgical Procedure

Your surgeon will make two or three small incisions, called portals, for the thin arthroscopic instruments. One instrument enables the surgeon to view the joint and another provides the heat source. Thermal capsular shrinkage uses energy, either laser or radiofrequency (sound waves), to heat the tissue.

The surgeon brushes the thermal probe back and forth across the tissues in the shoulder joint. He or she looks for changes in color and texture in the tissues as the probe touches them. It is important that the surgeon move the thermal probe across the tissue at the proper speed. Too fast and the tissue will not shrink, and too slow and the tissue may be burned. The entire procedure usually takes less than 1 hour.


After the procedure, some people may continue to experience shoulder instability and may eventually require open surgery to shorten and tighten the capsule. Others may develop stiffness or tightness of the joint (adhesive capsulitis).

Additional complications of thermal capsular shrinkage include:

  • Complete destruction or thinning of the shoulder capsule
  • Nerve injury from excessive heat
  • Rapid degeneration of the joint surface cartilage (chondrolysis) that leads to early arthritis

There is little pain after surgery. You must wear a sling for 4 to 6 weeks and take care not to raise or turn your arm. If you do not rest and protect your shoulder for a sufficient amount of time after surgery, you can stretch the tissues before they have healed in their shortened state. Your shoulder may then continue to be unstable.


Your surgeon will prescribe a rehabilitation program. Specific exercises will strengthen the muscles and restore a full range of motion to your shoulder.

Patients may be able to safely return to certain sports in as little as 4 to 6 months.

Long-Term Outcomes

Long-term results of thermal capsular shrinkage are not known at this time. Medium-term results have been less favorable than the short-term results.

Thermal capsular shrinkage must be undertaken with caution. The role of thermal capsular shrinkage for the treatment of shoulder instability is still being defined.

Last reviewed: September 2010
AAOS does not endorse any treatments, procedures, products, or physicians referenced herein. This information is provided as an educational service and is not intended to serve as medical advice. Anyone seeking specific orthopaedic advice or assistance should consult his or her orthopaedic surgeon, or locate one in your area through the AAOS "Find an Orthopaedist" program on this website.
Copyright 2010 American Academy of Orthopaedic Surgeons
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