Shoulder Injection


Bicipital Tendinitis (Tenosynovitis).
This is a nonspecific low-grade inflammation of the biceps tendon and/or its sheath and is more common in those who repeatedly flex at the elbow against resistance, such as weightlifters and swimmers. The tendon courses through the joint and along the bicipital (intertubercular) groove, which can be appreciated as the elbow is held at 90° of flexion, and the arm is internally and externally rotated. Patients may have restricted or normal range of motion and normal strength; however, they usually complain of tenderness to palpation over the bicipital groove. Efforts to elevate the shoulder, reach the hip pocket, or pull a back zipper all aggravate the symptoms. Tenderness over the bicipital groove does not confirm the diagnosis, however, because the supraspinatus tendon is in such close proximity to the bicipital tendon insertion. Other diagnostic clues include the Lipman test, in which “rolling” the bicipital tendon produces localized tenderness; the Yergason test, which elicits pain along the bicipital groove when the patient attempts supination of the forearm against resistance, holding the elbow flexed at a 90° angle against the side of the body; and Speed’s test, in which pain is reproduced on resisted forward elevation of the humerus against an extended elbow. Radiographs are normal and are not required if the clinical diagnosis is supported. Approach. The point of maximal tenderness of the
bicipital tendon is located. Entry is made with a 22- or 25-gauge, 3.9- to 5.0-cm needle through a lidocaine skin wheal. It is wise to avoid an actual intratendinous injection, which may cause weakening of the tendon and predispose the patient to tendon rupture. The needle is brought in along the side of the tendon at a 30° angle, aimed at one border of the bicipital groove to give a peritendinous infiltration. One third of the injection is administered at this point. The needle is then withdrawn slightly but is kept subcutaneous. It is redirected upward approximately 2.5 cm for another third of the injection, withdrawn again, and redirected downward, touching the bicipital border gently; the remainder of the drug is deposited at this point. With any of these injections, resistance to the injection suggests intratendinous needle placement, which should be avoided.26 If the two-syringe technique is used, 1 to 1.5 mL of an intermediate-acting corticosteroid suspension, such as prednisolone tebutate, is usually instilled at the maximum area of tenderness. The anesthetic (2–4 mL of 1% lidocaine or 0.25% bupivicaine) is injected along the upper and lower borders of the tendon.


Calcareous Tendinitis, Supraspinatus Tendinitis, and Subacromial Bursitis.
These inflammations are so clinically similar that their symptoms and signs are difficult to differentiate. The musculotendinous rotator cuff is composed of the supraspinatus, infraspinatus, teres minor, and subscapularis muscles, which insert as the conjoined tendon into the greater tuberosity of the humerus. The subacromial bursa lies just superior and lateral to the supraspinatus tendon. Both the tendon and the bursa are located in the space between the acromion process and the head of the humerus and are particularly prone to impingement in this “critical zone.” This can occur when the shoulder moves forward, compressing the cuff and bursa under the anterior third of the coracoacromial arch. Injections into either the bursa or the tendon sheath area are commonly performed secondary to inflammation and overuse. In calcareous (or calcific) tendinitis of the shoulder, a calcific deposit (hydroxyapatite) is within the substance of one or more of the rotator cuff tendons (commonly the supraspinatus). These calcium crystals can occasionally rupture into the adjacent subacromial bursa, causing acute pain and tenderness
in the deltoid area. The bursae in relation to the greater tuberosity and the subdeltoid (subacromial) bursa are the most common sites of calcific deposits. During the acute or hyperacute stage, the patient holds the arm in a protective fashion against the chest wall. Pain may be incapacitating, and all ranges of motion are disturbed, with internal rotation markedly limited. Tenderness is often diffuse over the perihumeral region. The patient may also complain of pain at night when lying on the affected side and with abduction of the arm. Supraspinatus tendon impingemen is most apparent with the humerus abducted and internally rotated. The Hawkins test elicits pain with forcible internal rotation while the patient’s arm is passively flexed forward at 90°, and Neer’s test elicits pain with full forward flexion between 70° and 120° degrees. Both tests are fairly sensitive, but not specific for supraspinatus tendon impingement.28 Constitutional symptoms are rare, but sometimes in the hyperacute form, actual swelling may be visible, and even fever and an accelerated sedimentation rate may develop. When shoulder radiographs demonstrate a calcific deposit, the shadow appears “hazy” with lightening of the periphery caused by the pressure of inflammatory edema. Night pain may be intolerable, requiring opioids for control. 

Anterior Approach:
In calcific tendinitis or supraspinatus tendinitis without calcification, the injection may be given by the anterior (subcoracoid) approach. The patient is asked to rest the extremity on the lap, and the arm is rotated externally about 15°. The point of insertion is over the depression that is palpable inferior and lateral to the coracoid process and medial to the head of the humerus.


Posterolateral Approach:
With the patient sitting and the lower part of the extremity resting on the lap, a lidocaine skin wheal is made at the depression about 1 cm inferior to the posterolateral tip of the acromion, located between the head of the humerus and the acromion. A 3.9- to 5.0-cm, 22- or 25-gauge needle is then directed toward the center of the head of the humerus and upward at an angle of approximately 10°. Because the bursa does not extend posteriorly beyond the midportion of the acromion, it is important that the needle be positioned sufficiently anterior and inferior to
the acromion. After the site has been penetrated 2 to 3 cm, aspiration is carried out for any fluid or calcific material. The syringe is then removed, leaving the needle in position. Another syringe containing 20 to 40 mg of methylprednisolone suspension or equivalent intermediate-acting steroid is attached, and the medication is instilled. Little resistance should be encountered when injecting the medication. If resistance is appreciated, then the needle should be repositioned, because it may be in the tendon substance of the rotator cuff. This injection can be followed with 4 to 6 mL of 1% lidocaine (or a similar volume of 0.25% bupivacaine).
Alternatively, local anesthetic can be given combined with the steroid in the same syringe. One should be generous with the volume of local anesthetic to ensure adequate dispersion of the steroid. A single treatment relieves the majority of acute disorders. An injection into the peritendinous space is similar to that described previously, except that the needle is advanced deeper than with a subacromial bursal injection. If calcific tendinitis is suspected, some recommend attempting to aspirate the calcium deposits. After the bursa has been anesthetized, an 18-gauge needle can be used to penetrate the calcium, often creating a “gritty” sensation. In addition, the clinician may consider the technique of barbatoge in order to facilitate the cleavage of calcium deposits, as well as the more diffuse dissemination of the injection. Using this method as previously described, the steroid or anesthetic/steroid combination is aspirated and reinjected repeatedly.
Sometimes, a painful reaction may follow when the analgesic has worn off. To avoid severe pain, the patient should be warned about this possibility and given appropriate analgesia. A sling may provide additional relief, and short-term use of opioids is appropriate. Whereas some authors claim that patients who do not also undergo physical therapy after corticosteroid injection have satisfactory results, some evidence supports the importance of close patient follow-up, range of motion exercises, and physical therapy to total recovery.

 

Acromioclavicular Joint Inflammation.
Pain arising in the acromioclavicular (AC) joint is frequently an aftermath of an acute injury, such as falling on an outstretched hand or weightlifting. With this injury, all ranges of motion of the shoulder cause pain, and the joint is tender but rarely swollen. The clinician should be aware of an obvious deformity or mechanism of action that may suggest an AC separation or dislocation. With AC joint inflammation, crepitus is not uncommon. Adduction of the arm across the body with forward elevation to 90° (the cross-arm test) may also exacerbate the pain, because the AC joint is compressed with such motion. In a study by Jacob and Sallay, injection of corticosteroids provided short-term relief of symptoms but did not alter the long-term course of patients with AC joint arthropathy. Hence, some clinicians feel that AC joint injection should be performed only in patients with persistent pain despite a trial of rest, oral anti-inflammatory medications, and activity modification. Approach. Entry is made through a cutaneous lidocaine wheal over the interosseous groove at the point of greatest tenderness. This is usually just at the AC joint,
which is palpated as a small V-shaped depression posteriorly at the most lateral aspect of the clavicle.25 The joint line is relatively superficial, and a 2.2- to 2.5-cm, 22- or 25-gauge needle is usually advanced only approximately 5 mm. 1 to 2 mL of lidocaine and 5 to 10 mg of a prednisolone suspension are injected. It is not necessary to advance the needle beyond the proximal margin of the joint surface.