The purpose of the study is to compare two different treatment regimens for primary frozen shoulder: Arthroscopic capsulotomy and arthrographic distention with steroid.

Patients with primary frozen shoulder will be randomized to two different treatments and the outcome will be measured.

Inclusion Criteria:

1. The patient must have understood all information about the project and must have signed the informed consent letter about participation in the study including rehabilitation and follow-up

2. The patients must have a history and clinical findings typical for primary frozen shoulder with globally reduced range of motion in the shoulder.

   • External rotation 20 degrees or less
   • Abduction 45 degrees or less

3. The patients must not be in phase 1 (inflammation phase)

4. Diabetics may be included

5. MRI must be taken to exclude other reasons for stiffness

Exclusion Criteria:

1. Other reasons for stiffness( cuff rupture, arthritis)
2. Posttraumatic or postoperative stiffness
3. Patients not suited for day surgery
4. Patients with a history of subacromial impingement before developing stiffness