Summary Lateral Epicondylitis (also known as Tennis Elbow) is an overuse injury caused by eccentric overload at the origin of the common extensor tendon, leading to tendinosis and inflammation of the ECRB. Diagnosis is made clinically with tenderness over the lateral epicondyle made worse with resisted wrist extension. Treatment is primarily nonoperative with NSAIDs, activity modification, and bracing. Rarely, operative management is indicated for patients with persistent symptoms who fail nonoperative management. Epidemiology Incidence most common cause for elbow symptoms in patients with elbow pain affects 1-3% of adults annually commonly in dominant arm Demographics affects up to 50% of all tennis players risk factors login to view 4 more bullets common in laborers who utilize heavy tools workers engaged in repetitive gripping or lifting tasks most common between ages of 45 and 64 years old men and women equally affected Etiology Pathophysiology mechanism tenodesis effect to optimize grip causes overuse of ECRB precipitated by repetitive wrist extension and forearm pronation common in tennis players (backhand implicated) pathoanatomy thought to begin as a microtear of the origin of ECRB may also involve microtears of ECRL and ECU a degenerative process as opposed to an inflammatory process pathohistology microscopic evaluation of the tissue reveals login to view 3 more bullets Associated conditions radial tunnel syndrome is present in 5% Anatomy Common extensor origin muscles that originate from lateral supracondylar ridge extensor carpi radialis longus muscles that originate on lateral epicondyle extensor carpi radialis brevis login to view 2 more bullets extensor carpi ulnaris extensor digitorum extensor digiti minimi anconeus login to view 1 more bullet Ligaments lateral ulnar collateral ligament Nerves posterior interosseus nerve (PIN) enters the supinator just distal to the radial head compression can lead to radial tunnel syndrome (may co-exist with lateral epicondylitis) Presentation Symptoms pain with resisted wrist extension pain with gripping activities decreased grip strength Physical exam palpation & inspection point tenderness at ECRB insertion into lateral epicondyle login to view 1 more bullet neuromuscular may have decreased grip strength neurological exam helps to differentiate from entrapment syndromes provocative tests the following maneuvers exacerbate pain at lateral epicondyle login to view 5 more bullets rule out intraarticular pathology and elbow instability LUCL insufficiency login to view 2 more bullets intraarticular pathology login to view 2 more bullets Imaging Radiographs recommended views AP/Lateral of elbow findings usually normal and very rarely change management may reveal calcifications near the lateral epicondyle (up to half of patients) may reveal signs of previous surgery MRI not necessary for diagnosis may be helpful to rule out other potential sources of pain if diagnosis is unclear increased signal intensity at ECRB tendon origin may be seen (up to 90% of cases) thickening or thinning edema tendon degeneration findings are not associated with symptom severity and should not dictate management Ultrasonography requires experienced operator (variable sensitivity/specificity) most useful diagnostic tool in experienced operator hands ECRB tendon appears thickened and hypoechoic Studies Histology histopathological studies of the ECRB tendon tissue shows fibroblast hypertrophy disorganized collagen vascular hyperplasia No inflammatory changes Diagnosis diagnosis is primarily based on symptoms and physical exam Differential Posterolateral plica Posterolateral rotatory instability Radial tunnel syndrome palpation 3-4 cm distal and anterior to the lateral epicondyle pain with resisted third-finger extension pain with resisted forearm supination Occult fracture Cervical radiculopathy Capitellar osteochondritis dissecans Triceps tendinitis Radiocapitellar osteoarthritis Osteochondritis dissecans Shingles Treatment Nonoperative activity modification, ice, NSAIDS, physical therapy, ultrasound indications login to view 1 more bullet techniques login to view 15 more bullets outcomes login to view 3 more bullets Operative release and debridement of ECRB origin indications login to view 3 more bullets technique login to view 1 more bullet contraindications login to view 2 more bullets outcomes login to view 2 more bullets Techniques Release and debridement of ECRB origin open incision is positioned over the common extensor origin lift ECRL off of ECRB (located deep and posterior to ECRL) Nirschl scratch test to assess for degenerative tendon excise degenerative tissue decorticate epicondyle watertight repair of capsule if breached to prevent synovial fistula side-to-side closure of tendon reattach tendon to epicondyle using an anchor or bone tunnel arthroscopic advantages include visualization and ability to address intraarticular pathology resect lateral capsule anteriorly (do not pass midradial head to protect LUCL) release ECRB from its origin (where muscle tissue begins) decorticate lateral epicondyle Complications Up to 40% of patients who undergo surgery still have some level of persistent pain Iatrogenic LUCL injury excessive resection of the LUCL should not extend beyond equator of radial head may lead to posterolateral rotatory instability (PLRI) Missed radial nerve entrapment syndrome common in up to 15% of patients with lateral epicondylitis Iatrogenic neurovascular injury radial nerve injury Heterotopic ossification decrease risk with thorough irrigation following decortication Stiffness especially if combined with an intraarticular procedure Infection Missed concomitant pathology (i.e. PLRI, radial tunnel) Prognosis Non-operative treatment effective in up to 95% of cases Factors associated with increased likelihood of requiring operative management depression, anxiety, and poor coping skills are greatest risk factors for poor outcome ipsilateral radial tunnel syndrome history of prior injection (any kind) workers' compensation