L-Shaped Arthroscopic Posterior Capsular Release in Frozen Shoulder

Abstract

Background:

The inadequate arthroscopic release of the tight posterior capsule in frozen shoulder may result in limited postoperative shoulder internal rotation.

Indication:

The purpose of this article is to describe an L-shaped arthroscopic posterior capsular release to overcome the limited internal rotation that may be encountered following the standard longitudinal technique. Operative intervention is indicated in patients with refractory shoulder stiffness with limitation of internal rotation of grade 0, +2, +4 (according to the Constant-Murley Score), after failure of conservative measures for 3 to 6 months. The technique is contraindicated if less than 3 months of physical therapy, shoulder stiffness due to osseous deformity, infection, or cuff tear arthropathy.

Technique:

After performing a standard anterior capsular release, the scope is shifted to the anterior portal to perform posterior capsular release by introducing the radiofrequency ablation device through the posterior portal. Posterior release begins from the glenoid level down to the 6 o’clock position until the back fibers of the infraspinatus muscle appear. Then the hook-tip part of the radiofrequency ablation device is used to perform a transverse release in the posterior capsule, starting from the beginning of the longitudinal limb. The transverse limb is performed in a stepwise manner going step-by-step laterally but ending before reaching the rotator cuff to avoid any damage of the cuff. After that, the shoulder was manipulated according to Codman technique.

Results:

A comparative study was performed on 43 patients with primary frozen shoulder to compare the standard longitudinal (22 patients) and L-shaped (21 patients) posterior capsular release. At the final follow-up, there was a statistically significant improvement in the internal rotation range of motion in the L-shaped group (P < .001). There was no loss of function over time. Moreover, there were no infections, instability, or axillary nerve injury in either group.

Discussion/Conclusion:

Restriction of internal rotation in frozen shoulder has been attributed to posterior capsular tightness. The L-shaped arthroscopic posterior capsular release in patients with primary frozen shoulder significantly improves the postoperative internal rotation range of motion.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

Frozen shoulder is a condition characterized by functional restriction of both active and passive shoulder motion which radiographs of the glenohumeral joint are essentially unremarkable except for the possible presence of osteopenia or calcific tendinitis. Different methods of treatment were described for treatment of frozen shoulder. Operative management is indicated after failure of conservative treatment that includes manipulation under anesthesia or the well-established arthroscopic capsular release.

The arthroscopic capsular release in frozen shoulder is used for refractory cases with reliable outcomes; however, there are controversies about the optimal type of release, but the principle is to do an adequate anterior and posterior release. However, the problem of inadequate posterior release may lead to tight internal rotation. After standard arthroscopic capsular release, the patient’s shoulder internal rotation may remain limited. This is usually attributed to inadequate release of the tight posterior capsule. Therefore, the postoperative limitation of internal rotation is considered a common complaint that diminishes the success of the procedure.

From this came the idea of L-shaped posterior capsular release that aims to improve the postoperative internal rotation range of motion, creates a large controlled posterior capsular opening, and prevents the postoperative reclosure of the released capsule encountered with the longitudinal release.

The patients selected in this technique should have shoulder pain with decreased range of motion as well as limited forward flexion and abduction as compared with the contralateral shoulder, with limited shoulder internal and external rotation. The indications for the procedure were failure to demonstrate progression in range of motion after 3 to 6 months of nonoperative care with limited internal rotation with a maximum score of +4 according to the Constant-Murley Score.

Contraindications for this technique include period of physical therapy less than 3 months, presence of shoulder stiffness due to osseous deformity or arthritis, infection, or the presence of cuff arthropathy.

The standard formal longitudinal release started with using the radiofrequency ablation device to do a longitudinal cut in the posterior capsule that ends with such a narrow opening. But with the newly described L-shaped capsular release after performing the longitudinal cut, a transverse limb is also used starting at the longitudinal cut and going back just before the cuff insertion and ends with such a large opening of the posterior capsule.

The patient is operated with general anesthesia, using interscalene block in semi-sitting modified beach chair position, the arm hanging freely that allows the shoulder to be easily mobile in all directions. Using the standard posterior portal, the arthroscope is introduced doing routine shoulder arthroscopy, and then the anterior portal is established using an outside-in technique.

The first step of the procedure is performing a standard adequate anterior capsular release. First, the rotator interval is opened. This is followed by release of superior and middle glenohumeral ligaments along with the coracohumeral ligament. Tip of the electrocautery device should face the articular side to avoid damage to the subscapularis and long head of biceps tendons. This is followed by the release of the anterior band of the inferior glenohumeral ligament.

The second step is performing a longitudinal posterior capsular release. The scope is switched using a switching stick that is introduced through the anterior portal. The arthroscope is then passed over this switching stick, and the radiofrequency ablation device is inserted through the posterior portal to perform the longitudinal limb of the release of the posterior capsule from the level of the glenoid down to the 6 o’ clock position. The motorized shaver is used to remove any debris after releasing the posterior capsule and removing any inflamed tissue until reaching and visualization of the infraspinatus muscle fibers on the back of the capsule.

The third step is performing the transverse limb of the L-shaped posterior capsular release; the hook-tip part of the radiofrequency ablation device is used, starting from the beginning of the longitudinal limb superior to the level of the axillary nerve. The transverse limb of the release is performed in a stepwise fashion going step-by-step laterally but ends before reaching the rotator cuff to avoid any damage of the cuff. Here you can realize that doing the release in a stepwise fashion removes any adhesions encountered between the capsule and the back fibers of the infraspinatus. Following adequate release, internal rotation is then checked and you can notice here the wide opening of the posterior capsule that increases the postoperative internal rotation range of motion.

After that, the shoulder is manipulated according to Codman technique, where the surgeon grasps the patient’s upper arm with his hand close to the axilla, and the surgeon’s contralateral hand stabilizes the scapula superiorly, thus creating a very short lever arm. The patient’s arm is then elevated in the plane of the scapula, where it is now in full external rotation. The arm is then brought down while maintaining its position in full external rotation to complete the tearing of the anterior capsule. The arm is subsequently adducted across the patient’s chest to extend the tear to the posterior capsule. Finally, the arm is manipulated in internal rotation to complete the posterior capsular opening.

The potential complications that maybe encountered during the procedure include posterior cuff injury while performing the transverse release of the posterior capsule. The subscapularis and long head of biceps tendons maybe injured during anterior capsular release. Moreover, the axillary nerve lies in a close proximity while releasing the capsule from the 5 o’clock down to the 7 o’clock position. Finally, iatrogenic fracture of the humerus can be avoided with gentle manipulation, sticking to the Codman technique and avoiding doing forceful aggressive maneuvers.

Postoperatively, pendulum circumduction and scapular retraction exercises are immediately encouraged from day 1. Passive and active assisted range of motion exercises are started within the first week, as well as gentle posterior capsular mobilization. This is followed by active range of motion exercises which are usually started after 2 weeks postoperatively. In addition to that, patients are advised to start a home-based exercise program at least 3 times daily. Finally, return to work and activity is allowed after 2 months following surgery.

Our study concluded that 21 of 43 patients had undergone L-shaped posterior capsular release. They demonstrated a significant postoperative improvement only in internal rotation compared with the patients who had a standard longitudinal posterior release. There were no postoperative complications in our series.