By Dr. Snehal Panchal,Pain Management
The inflammation of the capsule of the shoulder and its synovial lining is called as frozen shoulder, in which there is a contracture of the gleno-humeral joint. This generalized contracture leads to shoulder pain accompanied by a loss of active as well as passive range of motion. It is described to be a self-limiting condition that falls under the category of disease of unknown etiology. Codman was the first to describe frozen shoulder, which was further explained by Neviaser to be a pathology involving the capsule of the shoulder joint. It is therefore also called as ‘Adhesive capsulitis’.
The characteristic finding of frozen shoulder is severe pain that causes a restriction of movement. The external passive rotation movement becomes limited. Management of this condition involves strategies for pain alleviation and restoration of the normal shoulder function.
Primary aim of treatment is to restore the shoulder function. Treatment options that are usually administered for frozen shoulder include adequate rest, non-steroidal anti-inflammatory drugs (NSAIDs) for pain relief, active and passive mobilization of the affected shoulder, injections of corticosteroids or hyaluronate intra-articularly, anesthetic manipulation and surgical management by capsular release. Patient’s active participation and co-operation is essential to conduct exercises for providing pain relief. To enable pain relief, regional nerve block is administered prior to the exercise session.
The supra-scapular nerve block is considered to be the most effective and accepted method for shoulder pain management. Synovial fluid inflammation and fibrous involvement of the shoulder joint capsule is the pathological process that affects the joint. Proliferation of the fibroblasts producing a chronic inflammation suggests the process to be immune-modulated. Since it is a benign and self-limiting disorder, it is expected to resolve by itself over a period of 2 years or less. But patients that present with severe stiffness of the shoulder are advised anesthetic manipulation. Regular physiotherapy under supervision of the physician is essential to ensure a painless shoulder with an improved range of motion. Codman’s manipulation is a motion of the shoulder joint that causes an indirect rotation of the humerus, without any rotational torque placement on the humerus.
- Inflammatory- This stage shows a pain-limited range of motion of the shoulder joint.
- Freezing- Freezing stage shows a hyper-vascular synovitis.
- Frozen- Synovitis is reduced and the capsule shows presence of a dense scar.
- Thawing- This stage shows resolution of the inflammation.
The diagnostic criteria for frozen shoulder given by Codman in the 1934 proposes the following symptoms-
- Slow onset shoulder pain,
- Pain at the insertion of deltoid muscle,
- Difficulty in lying down on the affected side,
- Atrophied supraspinatus and infraspinatus muscles,
- Restricted active and passive range of motion,
- Restricted elevation and painful external rotation.
Axillary nerve and the supra-scapular nerve provide the nerve supply to the shoulder joint, with some small branches from the lateral pectoral and sub-scapular nerves. Suprascapular nerve supplies a majority of the sensory fibers of the shoulder joint and also the acromio-clavicular joint along with the capsule and skin overlying it. For administering the supra-scapular nerve block, anatomical landmarks are palpated. These landmarks are spine of scapula, acromion, clavicular and the acromio-clavicular joint. Direct or indirect approaches for nerve block administration are used.
Risk of pneumothorax is decreased in the indirect technique. However, the use of the anatomic landmarks has now been replaced by the use of imaging guidance for an accurate placement of needle in the joint space. The superior, posterior and lateral approaches for needle placement are described. Blocking of the nerve at specific sites is aided by these approaches. When the conservative management of frozen shoulder through pain medications, physiotherapy, steroid injections in the joint do not produce desired effect on the joint, the suprascapular nerve block is applied. Failure of all the interventional therapies indicate the need for an arthroscopic or open surgical procedure. The nerve block is aimed to decrease pain and provide an efficient restoration of shoulder mobility.
Comparative studies between the effectiveness of the nerve block and intra-articular steroid injection have shown that suprascapular nerve block is a better adjunct for managing chronic shoulder pain. It is a safe and cost-efficient therapy for pain reduction in many shoulder pathologies, which can be repeated without any reported complications. Minor complications include transient dizziness, weakness in the arm and facial flushing. A pain free physical therapy and alleviation of chronic pain is efficiently achieved by the suprascapular nerve block.