Bursae Injections

Bursitis is commonly diagnosed and treated in clinical practices that focus on musculoskeletal medicine. Inflamed bursae often respond to conservative treatments including rest, cryotherapy, compression, physical/occupational therapy and nonsteroidal antiinflammatory drugs (NSAIDs). In patients who fail to respond to conservative rehabilitation, a corticosteroid injection into the bursa can serve as a useful diagnostic and therapeutic adjunct to a comprehensive course of rehabilitation.

Bursae are purse-like sacs containing fluid and function to reduce friction at a joint. They are positioned between two muscles or between a muscle and its tendon or bone. Inflammation may occur during repetitive activities involving poor body mechanics or following direct trauma. An accurate diagnosis includes a thorough history, and an investigation of the occupational and recreational factors predisposing a patient to repetitive overload or joint stress. Correction of improper biomechanics is essential to reduce joint tension early in the course of treatment to avoid chronic bursitis.

Physical examination will reveal focal tenderness, swelling, and pain during direct palpation. If the injury is due to acute trauma, a fracture or ligamentous instability of the joint should be considered. In cases of chronic bursitis, calcifications may be identified on plain radiographs. However, the most common etiology combines repetitive motion with improper biomechanics. The physical examination should include a survey of peripheral joints to rule out a systemic process such as an underlying rheumatic disease. Skin overlying the area of tenderness should be examined for evidence of warmth, redness, swelling, or penetrating trauma. Rarely an infected bursa is diagnosed, and skin warmth appreciated on palpation may be the most sensitive physical indicator. The treatment of bursitis requires that an infection be considered prior to initiating treatment protocols. Aspiration of a septic bursa and identification of a bacterial pathogen are necessary to initiate appropriate antibiotic treatment. Laboratory studies of the serum should include an erythrocyte sedimentation rate, complete blood cell count, and microscopic examination to screen for leukocytosis, bacteria on Gram stain, or crystals. Operative incision and drainage of a septic bursa may be required for effective treatment. Contraindications to bursal injection with corticosteroids include cellulitis, generalized infection, and coagulation disorders.

Bursal injections serve a diagnostic and a therapeutic role. An initial bursal injection with local anesthetic alone can provide important information that will confirm the diagnosis. Bursitis from a noninfectious etiology may be considered for an injection of corticosteroid and anesthetic reducing bursal pain and inflammation, thereby allowing the patient to engage in a comprehensive rehabilitation program. Following the injection, the patient should be given instructions to ice and observe relative rest prior to resumption of a therapeutic exercise program. The clinician should direct the patient in a home exercise program and a physical therapist may be consulted for soft tissue mobilization and instruction in a stretching and strengthening program. Ice may be a useful adjunct during the initial phases of treatment, and NSAIDs may provide additional relief. Each of these options should be individualized for the clinical situation, and none of these, especially bursal injections, is to be used as the primary form of therapy. Re-examination should be scheduled within the first few weeks, and the rehabilitative program should be tailored to the patient as symptoms subside.

This chapter describes the basic approach to injection of many of the bursae encountered in clinical practice. Although the rehabilitation program for each bursa has not been detailed to allow for closer attention to procedural techniques, it is essential to employ a comprehensive rehabilitation to maximize the success of injections.

Subacromial (Subdeltoid) Bursitis

The subacromial bursa rests on the supraspinatus and is covered by the acromion, the coracoacromial ligament, and the deltoid. This is the most common site of bursitis of the shoulder, with inflammation usually occurring secondary to rotator cuff tendinitis or shoulder impingement syndrome. In a pure subacromial bursitis, the impingement signs may be absent, and the inflamed bursa may limit full passive abduction due to compression at the near end range of shoulder motion. More commonly, subacromial bursitis coexists with impingement syndrome or rotator cuff syndrome. Determining the etiology of shoulder pain may be difficult, and a diagnostic injection into the bursa can narrow the field of possibilities. A diagnostic injection may help distinguish weakness and loss of range of motion secondary to a painful bursitis from a full-thickness rotator cuff tear. The patient should be thoroughly examined prior to the administration of local anesthetic and then reexamined 5 to 10 minutes after injection. Postinjection, the patient may be less guarded and more cooperative during the physical examination, yielding further diagnostic information.

Although an anterior, posterior, or lateral approach may be used, the posterolateral approach is preferred. Following sterile technique, the skin is cleansed with povidone-iodine, and the patient is directed to retract the shoulder to a neutral posture. The posterolateral angle of the acromion is identified by palpation, and the needle is advanced in an anteromedial and slightly inferior direction ( Figs. 11-1 and 11-2 ). If the soft tissues resist needle insertion, a small volume can be injected to expand the bursa so that the needle can be advanced further, resulting in optimal needle position. A mixture of 2 to 4 mL of 1% or 2% lidocaine hydrochloride and 2 to 4 mL of 0.5% bupivacaine hydrochloride is injected into the bursa after a 25-gauge, 1.5-inch needle is introduced approximately 1 inch. In the authors’ experience, an inflamed subacromial bursa accepts 4 to 6 mL of total volume. Following the injection, a reduction of pain with improved strength supports the diagnoses of shoulder impingement, supraspinatus tendinitis, and subdeltoid bursitis. Patients who respond with greater than 50% relief are good candidates for an immediate follow-up injection with 1 mL of betamethasone sodium phosphate. Alternatively, the anesthetics can be mixed with the corticosteroids and administered in a single injection when the clinical examination is clear. Subacromial bursography is helpful when the initial blind anesthetic injection is unsuccessful or in a patient whose diagnosis is unclear. A normal bursogram casts doubt on a diagnosis of subacromial impingement.

The strengthening component of a rehabilitative program should not progress too rapidly after corticosteroid injection, to avoid aggravation of inflammation and to avoid the rare risk for tendon rupture.

Olecranon Bursitis (Draftsmen’s Elbow)

The olecranon bursa is subcutaneous, protecting the proximal ulna frequently subjected to trauma. Inflammation of this bursa is commonly associated with rheumatologic disorders. Aspiration of the bursa should always precede injection and may be helpful to ensure proper location of the needle because the wall of the bursa is often thickened and fibrotic from chronic irritation. Gout may be seen at the olecranon, and any bursal fluid aspirated should undergo microscopic examination for crystals. Aspiration of the bursa is more successful using a larger bore needle (18 gauge), because the fluid may be gelatinous. The needle enters the skin perpendicular to the central swelling while the clinician withdraws on the syringe ( Fig. 11-3 ). The procedure is followed with the application of a compressive dressing, and the patient is instructed to protect the elbow from further trauma. Persistent cases may benefit from a low-dose corticosteroid injection. Rarely, surgical excision or an arthroscopic bursectomy is warranted after failure of conservative measures.

Trochanteric Bursitis

Several bursae may be implicated in trochanteric bursitis. The subgluteus maximus bursa lies lateral to the greater trochanter and the insertion of the gluteus medius and minimus. The subgluteus medius bursa is situated superior and posterior to the trochanter. The gluteus minimus bursa lies anterior to the trochanter. All three bursae may be part of a greater trochanteric pain syndrome.

Trochanteric bursitis is commonly seen in an elderly population and manifests as pain in the lateral thigh during ambulation. Patients may describe a pseudoradicular pattern with the pain extending down the lateral aspect of the lower extremity and into the buttock. The symptoms can be elicited by placing the lower extremity in external rotation and abduction. Direct palpation or deep pressure applied posterior and superior to the trochanter will reproduce the pain. The patient should be examined for limitations in flexibility involving the gluteus maximus, medius, and minimus and the tensor fasciae latae. Trendelenburg gait as a result of hip abduction weakness may contribute to increased friction and irritation of the bursa. If the history and physical examination are consistent with bursitis, a corticosteroid combined with anesthetic agent is delivered via a 3.5-inch, 22-gauge needle directed at the point of maximal tenderness overlying the greater trochanter ( Fig. 11-4 ). Persistent hip pain despite injection therapy and comprehensive rehabilitation should alert the physician to alternate sources of pain including the lumbar spine, hip joint, and distal lower extremity joints.