Elbow tendinosis is a result of tendon overuse and a failure of tendon healing.

Elbow tendinosis can affect the elbow laterally (extensor carpi radialis brevis [ECRB], extensor digitorum communis), medially (pronator teres, flexor carpi radialis), or posteriorly (triceps) (6).

Initial symptoms are activity-related pain followed by pain at rest as the condition becomes more chronic.

Repetitive activities, such as golf, tennis, and typing, are often the inciting activities for this condition.

Some loss of extension is common in medial elbow tendinosis, but often the patients maintain full range of motion.

Tenderness over lateral or medial tendon origins or posterior insertion of triceps.

Pain with provocative procedures (resisted wrist/finger extension for lateral tendinosis, wrist flexion/pronation for medial tendinosis, and elbow extension for posterior tendinosis).

Because medial and lateral affected tendon units cross the elbow joint, pain is more severe with provocative testing with the elbow in extension. Therefore, pain with provocative testing with the elbow flexed indicates more severe involvement.

Functional strength loss is common.

Histology of surgically resected tissue fails to reveal inflammatory cells. Thus, the term “tendinosis” is preferable to “tendonitis.”

The epicondyle (bone) itself is not affected in the disease process. Therefore, epicondylitis is a misnomer. However, a bony exostosis may be noted as a companion problem in 20% of lateral elbow tendinosis cases.

Pathologic tendinosis shows disruption of normal collagen matrix by the characteristic invasion of fibroblasts and vascular granulation tissue termed “angiofibroblastic proliferation” (8).

Lateral tendinosis can be confused with the rare entity of posterior interosseous nerve (PIN) entrapment, which would have diffuse pain along the radial nerve in the extensor mass of the proximal forearm, painful resisted supination, and electromyography (EMG) changes of distal muscle groups (5).

Lateral tendinosis can be seen in combination or association with intra-articular abnormalities, such as synovitis, plica, chondromalacia, and osteochondritis dissecans (OCD).

Medial elbow-associated abnormalities may include degeneration/rupture of medial collateral ligament, entrapment of the ulnar nerve, and congenital subluxation of the ulnar nerve.

Posterior elbow-associated abnormalities may include extraarticular olecranon bursitis and intra-articular olecranon fossa issues (synovitis, chondromalacia, and loose fragments).

The mesenchymal syndrome, coined by Nirschl, has been used to describe a subset of patients with apparent decreased tissue durability who present with multiple affected areas that are often bilateral, including rotator cuffs, medial and lateral elbow tendinosis, carpal tunnel syndrome, trigger finger, de Quervain disease, plantar fasciosis, Achilles insertional tendinosis, and hip trochanteric bursitis (6).

Anti-inflammatory medications can be helpful in controlling pain and can be a first-line therapy, allowing patients to comfortably proceed with curative rehabilitative exercises.

Promotion of a tendon healing response (neovascularization and fibroblastic infiltration with collagen deposition and maturation) can be accomplished by