Medial Epicondyle Injection

Medial epicondylitis of the elbow is a lesion of the common flexor tendon at the medial epicondyle (see the image below).[1, 2]  This condition, also known as golfer's elbow, occurs primarily in golfers with faulty pullthrough, tennis players who have a twist American serve, and throwers.[3]  It is substantially less common than lateral epicondylitis.[4]  For information on injection for lateral epicondylitis, see Lateral Epicondyle Injection.

Medial epicondyle.

The diagnosis of medial epicondylitis is based on a history of pain over the medial epicondyle and the following findings on physical examination[5] :

• Local tenderness directly over the medial epicondyle
• Pain aggravated by resisted wrist flexion and radial deviation
• Pain aggravated by strong gripping or decreased grip strength
• Normal elbow range of motion (ROM)

The histopathology of the affected musculature reveals edema and fibroblast proliferation in the subtendinous space, tendinopathy with hypervascularity (particularly involving the flexor tendon), and spur formation with a sharp longitudinal ridge on the epicondyle.[6]

Patients report local tenderness and aching pain around the medial epicondyle while performing certain movements. Pain on resisted wrist flexion with the elbow in extension is the most reliable sign. Rarely, flexion of the fingers rather than of the wrist best elicits symptoms.

Corticosteroids often are injected in and around soft-tissue periarticular lesions to treat regional pain syndromes.[7, 8]  Epicondylitis can be treated successfully in 90% of cases by local corticosteroid injection into the tender tendon origin at the humeral epicondyle.[3]  No more than two repeat injections should be given, and the arm should not be strained for at least 3 months afterwards.

Ultrasonographically guided injection of platelet-rich plasma (PRP) for chronic tendinopathy has been described at various sites, including the medial epicondyle.[9, 10, 11, 12, 13, 14]  Injection of bone marrow aspirate concentrate, collagen-producing cells, and stem cells has also been described.[15]

Pulsed therapeutic ultrasound, when used optimally, can be an effective alternative to injection. It is nonpainful but is less frequently successful.[16, 17]

Indications for medial epicondyle injection include the following:

• Failure of conservative treatment
• To shorten the symptomatic period ^[18]  (long-term outcome in patients who receive injection is similar to that in patients who do not)
• To speed up recovery in high-performance athletes, though this is a controversial practice

Joint or soft-tissue aspirations and injections have few absolute contraindications. The procedure should probably be avoided if the overlying skin or subcutaneous tissue is infected or if bacteremia is suspected.[3, 19]  The presence of a significant bleeding disorder or diathesis or severe thrombocytopenia may also preclude joint aspiration.[3, 19]  Lack of response to previous injections may be a relative contraindication.

Aspiration of a joint with a prosthesis in it carries a particularly high risk of infection and is often best left to a surgeon using full aseptic techniques.[3]  If infection is suspected as the underlying cause of the musculoskeletal problem, injection of corticosteroid must be avoided for fear of exacerbating the infection.

Warfarin anticoagulation with international normalization ratio (INR) values in the therapeutic range is not a contraindication for joint or soft-tissue aspiration or injection.

Aspiration or injection of soft tissues may be performed as an outpatient procedure and does not require specialized equipment.[20]  The following items are used:

• Needle, 25 or 27 gauge
• Readily available syringes for injection (3-5 mL)
• Methylprednisolone acetate 30-40 mg
• Lidocaine 1% (0.5-1 mL) without epinephrine

Anesthesia

Experienced physicians often prefer to use topical ethyl chloride or no anesthetic at all. The latter is often appropriate for joint aspiration; the capsule is difficult to anesthetize, and a single quick needle thrust may be much less painful than the administration of local anesthesia.

Positioning

Place the patient in a comfortable supine position; this facilitates relaxation and guards against possible fainting.[3]  Have the patient flex the affected elbow to 90º with 90º of shoulder rotation. Mark the medial epicondyle and the olecranon process. (See the image below.)

Medial epicondyle injection site.

Corticosteroid injections and infiltrations are basic treatment tools in rheumatology. Injection of other substances, including platelet-rich plasma (PRP), bone marrow aspirate concentrate, collagen-producing cells, and stem cells, has also been described. in this setting.[15, 10, 9]

Corticosteroid injections and infiltrations carry minimal risk to the patient when properly indicated and performed. Technical difficulties vary; some injection and infiltration procedures require specialized knowledge for optimal results.

Follow sterile precautions throughout the procedure. Clean the skin carefully with antiseptic agents. Ethyl chloride may be applied to the skin for anesthesia.

Insert a 5/8-in. (~1.6 cm) 25-gauge needle perpendicular to the skin, 1/2 in. (~1.25 cm) distal to the center of the epicondyle (if the patient has sufficient subcutaneous fat), or at 45º, to a depth of 3/8-5/8 in. (~1.0-1.6 cm). (See the image and video below.)

Medial epicondyle injection.

Inject 0.5 mL of lidocaine subcutaneously and 0.5 mL at the tendon/fat. Inject at the most tender point. Avoid injecting too superficially. Infiltrate the corticosteroid deeply at the tenoperiosteal junction. Always inject the corticosteroid at the tissue plane between the subcutaneous fat and the tendon. At the end of the injection, withdraw the needle swiftly, and apply light pressure over the needle site.

A painful reaction to injection or firm resistance during injection suggests that the needle is too deep and is within the body of the tendon; if this occurs, withdraw the needle 1/8 in. (~3 mm). The needle should move freely with skin traction if the tip is above the tendon; conversely, the needle sticks in place if the tip is within the body of the tendon.

Lack of improvement with lidocaine infiltration suggests an alternative diagnosis, such as compressive neuropathy of the median nerve or cervical radiculopathy. Reinjection may be necessary in 4-6 weeks if symptoms have not been reduced by at least 50%. Surgical consultation can be considered if two injections combined with wrist immobilization fail to resolve the condition. Patient-related risk factors for injection failure necessitating surgical treatment include age less than 65 years and obesity (body mass index [BMI] >30).[21]

For the chronic case, no more than four injections should be performed in the same arm. Débridement with restoration of the flexor-pronator origin may be efficacious for restoring function and relieving pain in recalcitrant cases of medial epicondylitis.[22]

Surprisingly few complications arise as results of these procedures.[3]  The most significant issue is the risk of infection. Care must always be taken to use sterile no-touch techniques. Corticosteroids are contraindicated in patients with septic arthritis. The estimated risk of septic arthritis following a corticosteroid injection is on the order of 1 per 15,000 procedures. Patients with severe immunodeficiency or implants may be at greater risk of complications.

The best-described complication is tendon rupture following corticosteroid injections for tendinitis. The risk of this complication can be minimized by avoiding injection into the tendon itself. No therapeutic agent should be injected against any unexpected resistance. Frequent cortisone injections can lead to tendon rupture and should be avoided.

Occasionally, nerve damage can also result from a misplaced injection (eg, median nerve atrophy following attempted injections for carpal tunnel syndrome). Other complications can arise from misplaced injections.

Transient increase in pain is seen in 20-40% of patients. Repeated corticosteroid infiltrations may result in chronic pain.

Superficial corticosteroid infiltrations often cause a hypopigmented patch,[23] which may be quite disfiguring in people with dark skin. The condition resolves in a few months to 2 years.

Skin atrophy[23] is a frequent complication of superficial infiltrations.

Rarely, corticosteroid injections can cause transient pituitary inhibition that may last as long as several days. Serial infiltrations may cause adrenal suppression and result in acute adrenal crisis.

Patients who have undergone serial injections are at greater risk for localized osteoporosis.