The ulnar collateral ligament (UCL) is the primary stabilizer of the medial (inner) elbow against valgus stress. It runs from the medial epicondyle of the humerus to the coronoid process of the ulna, and is the most commonly injured ligament in overhead throwing athletes.

UCL injuries frequently co-exist with other medial elbow problems — including medial epicondylitis and ulnar nerve irritation — making accurate MRI evaluation essential for planning the right treatment.

Causes

Sports-related causes

UCL tears are strongly associated with repetitive overhead throwing. Baseball pitchers, quarterbacks, javelin throwers, and tennis players place extreme valgus stress on the medial elbow with every throw or serve. Over time, this cumulative load leads to attenuation and eventual tearing of the ligament. Acute complete ruptures can also occur from a single traumatic event, such as a hard fall on an outstretched hand.

Other contributing factors

A number of additional factors increase the risk of UCL injury beyond the primary throwing mechanism:

• Poor mechanics: Incorrect throwing technique — improper arm position, poor follow-through, or inadequate trunk rotation — increases the load placed on the UCL with each throw.
• Overloading and inadequate recovery: Training too intensively without sufficient rest prevents the ligament from adapting, accelerating the accumulation of micro-damage over time.
• Age and degeneration: Ligaments naturally lose elasticity with age, making the UCL more susceptible to tearing even with lower-force activities in older athletes and workers.
• Previous elbow injury: A history of UCL sprains or other elbow injuries weakens the ligament's structural integrity and significantly raises the risk of a more serious tear.
• Ligamentous laxity: Some individuals have a constitutional tendency toward looser ligaments, which can predispose the UCL to injury under loads that would not affect others.
• Manual labor and non-sport activities: Repetitive stress on the inner elbow from certain occupational tasks and activities such as gymnastics can cause UCL injury outside of traditional throwing sports.

Symptoms

The hallmark symptom is medial elbow pain during and after throwing or overhead activity. Patients may notice a gradual decline in throwing velocity or accuracy before pain becomes significant. Acute tears can produce a sudden pop on the inner side of the elbow, followed by immediate pain, swelling, and inability to continue throwing. Elbow instability — a feeling that the joint is giving way — may also be present.

Diagnosis

Physical examination typically reveals tenderness directly over the UCL and pain with valgus stress testing (the moving valgus stress test). Ulnar nerve symptoms such as tingling in the ring and small fingers may accompany the injury. Plain X-rays are often normal but may show calcification within the ligament in chronic cases.

MRI is the imaging study of choice for UCL evaluation. A dedicated elbow MRI can identify partial or complete ligament tears, surrounding edema, and any associated injuries to cartilage, bone, or the ulnar nerve. MRI arthrography (with contrast injected into the joint) is sometimes used for subtle partial tears when standard MRI is equivocal.

Injury grades

UCL injuries are graded by the degree of ligament disruption:

• Grade 1 (Sprain): Ligament fibers are stretched but intact; mild edema within and around the ligament.
• Grade 2 (Partial tear): Some fibers are torn; the ligament is lax and weakened but maintains continuity.
• Grade 3 (Complete tear): Full-thickness disruption of the ligament with loss of medial elbow stability.

Treatments

Treatment depends on the grade of injury, the patient's activity level, and whether return to overhead sport is a goal.

Grade 1 and 2 injuries in recreational or non-throwing patients: Rest, activity modification, anti-inflammatory medication, and a structured physical therapy program focused on strengthening the flexor-pronator muscle group are usually effective. A hinged elbow brace may be used during recovery.

Grade 2–3 injuries in competitive throwing athletes

Athletes who wish to return to high-level overhead sport often require surgical reconstruction — the well-known "Tommy John surgery" — in which the UCL is replaced with a tendon graft (typically from the palmaris longus or a hamstring). Rehabilitation after UCL reconstruction typically takes 12–18 months before return to competitive throwing.

Grade 3 injuries in older or non-overhead patients

Patients who do not require the elbow stability demanded by overhead sport may be managed non-operatively with bracing and therapy, accepting some degree of residual laxity in exchange for avoiding surgery.

Related Elbow Conditions

• Osteochondral Defect of the Elbow
• Biceps Tendinopathy / Biceps Tear
• Epicondylitis (Tennis Elbow / Golfer's Elbow)
• Olecranon Bursitis
• Back to all Elbow Conditions

An osteochondral defect (OCD) of the elbow is an injury to the articular cartilage and the underlying bone, most commonly affecting the capitellum — the rounded portion of the lateral humerus that articulates with the radial head. It is most frequently seen in young overhead and throwing athletes.

OCD lesions of the elbow are closely associated with repetitive lateral compression forces and are often found alongside other lateral elbow pathology. In some cases, a loose body — a fragment of cartilage or bone — can break free into the joint, causing locking or catching symptoms similar to those seen with UCL instability on the medial side.

Causes

Sports-related causes

Repetitive compressive loading across the lateral elbow — as occurs with throwing, gymnastics, and racquet sports — is the primary driver of capitellar OCD. Young athletes with open growth plates are particularly vulnerable, as the blood supply to the capitellum is tenuous during adolescence, making it susceptible to avascular necrosis (Panner's disease) in younger children and OCD in older adolescents.

Traumatic causes

A single significant impact — such as a fall on an outstretched hand — can produce an acute osteochondral injury, although this is less common than the repetitive stress mechanism.

Symptoms

Lateral elbow pain that worsens with activity is the most common complaint. Patients may notice stiffness and a loss of full elbow extension. If a loose body is present, mechanical symptoms such as locking, catching, or a sensation of something moving within the joint may occur. Swelling and tenderness over the lateral elbow are common on examination.

Diagnosis

X-rays may show irregularity of the capitellum or a visible loose body but are often normal in early disease. MRI is the definitive imaging tool for assessing the size, stability, and depth of the lesion, the integrity of the overlying cartilage, and the presence of any loose bodies within the joint.

A dedicated elbow MRI allows the radiologist to stage the lesion accurately and determine whether it is stable (intact cartilage surface) or unstable (cartilage fissured or fragment detached), which is the key factor driving treatment decisions.

Classification

OCD lesions of the elbow are commonly staged by MRI appearance:

• Stage I: Thickening or signal change in the subchondral bone; cartilage surface intact.
• Stage II: Fissuring or partial detachment of the cartilage; fragment still in place.
• Stage III: Complete detachment — loose body free within the joint.

Treatments

Treatment is guided by lesion stage, patient age, skeletal maturity, and activity level.

Stable lesions (Stage I–II) in skeletally immature patients: Activity restriction and rest from overhead sport for 3–6 months, with physical therapy to maintain motion and strength. Many stable lesions in young patients will heal with conservative management. Serial MRI may be used to monitor healing progress.

Unstable or Stage III lesions in active patients

Surgical intervention is typically recommended for unstable lesions, loose bodies, or cases that have failed conservative management. Options include arthroscopic removal of loose bodies, drilling or microfracture to stimulate healing in the subchondral bone, and fixation or replacement of larger osteochondral fragments. Return to sport after surgery typically takes 6–12 months.

Older or lower-demand patients

In patients who are skeletally mature and not pursuing overhead sport, conservative management with activity modification and symptom control may be appropriate even for more advanced lesions, provided mechanical symptoms are not significantly limiting function.

Related Elbow Conditions

• UCL Tear
• Biceps Tendinopathy / Biceps Tear
• Epicondylitis (Tennis Elbow / Golfer's Elbow)
• Olecranon Bursitis
• Back to all Elbow Conditions

The distal biceps tendon attaches the biceps muscle to the radial tuberosity at the elbow, where it plays a critical role in forearm supination (rotating the palm upward) and elbow flexion. Biceps tendinopathy refers to degeneration and pain within the tendon, while a biceps tear involves partial or complete disruption of the tendon fibers.

Distal biceps injuries are distinct from proximal biceps problems at the shoulder. At the elbow, a complete rupture is a significant injury that causes meaningful loss of supination strength — unlike a proximal rupture, spontaneous healing does not occur and surgical repair is often required in active patients. Distal biceps tears may be associated with other anterior elbow pathology, and olecranon bursitis can occasionally develop as a secondary finding after elbow trauma.

Causes

Acute causes

Complete distal biceps tears most commonly result from a sudden, forceful eccentric load — typically when lifting a heavy object while the elbow is partially flexed. Middle-aged men are most commonly affected. The classic mechanism is attempting to catch a falling weight or resist an unexpected load.

Degenerative causes

Biceps tendinopathy develops gradually from repetitive elbow flexion and supination activities — common in weightlifters, laborers, and overhead workers. Chronic tendinopathy can weaken the tendon and predispose it to partial or complete tearing over time.

Symptoms

An acute complete tear produces sudden, sharp anterior elbow pain, often accompanied by an audible or felt pop. Bruising and swelling in the antecubital fossa (front of the elbow) develop quickly. The characteristic "reverse Popeye" deformity — the biceps muscle belly bunching up toward the shoulder rather than away from it — may be visible. Supination strength is notably reduced.

Tendinopathy without tearing causes anterior elbow pain and tenderness that is aggravated by resisted elbow flexion and forearm supination, without the acute pop or deformity of a complete tear.

Diagnosis

Clinical examination — including the hook test, in which the examiner attempts to hook a finger under the biceps tendon — is highly accurate for detecting complete tears. However, partial tears, tendinopathy, and assessment of retraction distance all require imaging.

A dedicated elbow MRI is the gold standard for evaluating the distal biceps tendon. MRI can distinguish tendinopathy from partial tearing, identify the degree of retraction in complete tears, and detect associated injuries to surrounding structures — all critical information for surgical planning.

Injury classification

• Tendinopathy: Tendon thickening, increased signal on fluid-sensitive sequences, and peritendinous edema without fiber disruption.
• Partial tear: Focal disruption of some tendon fibers with the remaining tendon still attached to the radial tuberosity.
• Complete tear: Full-thickness disruption with variable degrees of proximal retraction of the tendon stump.

Treatments

Treatment depends on the type and severity of injury, patient age, and functional demands.

Tendinopathy and low-grade partial tears: Activity modification, physical therapy focusing on eccentric strengthening, and anti-inflammatory measures are first-line. Platelet-rich plasma (PRP) injection is sometimes used for refractory tendinopathy. Most patients improve with a structured conservative program over 8–12 weeks.

Complete tears and high-grade partial tears in young or active patients

Surgical repair is strongly recommended for complete distal biceps tears in active patients, ideally within 2–3 weeks of injury before significant retraction and scarring occur. The tendon is re-anchored to the radial tuberosity using suture anchors or an endobutton technique. Outcomes are excellent when repair is performed early, with near-full restoration of supination and flexion strength.

Complete tears in older or low-demand patients

Patients who do not rely on forearm supination strength for work or sport may opt for non-surgical management, accepting a permanent reduction in supination power (approximately 40%) and some loss of elbow flexion strength in exchange for avoiding surgery and rehabilitation.

Related Elbow Conditions

• UCL Tear
• Osteochondral Defect of the Elbow
• Epicondylitis (Tennis Elbow / Golfer's Elbow)
• Olecranon Bursitis
• Back to all Elbow Conditions

Epicondylitis is a painful overuse condition affecting the tendon origins at the elbow. Lateral epicondylitis — commonly called tennis elbow — involves the common extensor tendon origin at the lateral (outer) epicondyle. Medial epicondylitis — golfer's elbow — involves the common flexor-pronator tendon origin at the medial (inner) epicondyle. Both conditions are characterized by tendon degeneration rather than true inflammation.

Medial epicondylitis shares the medial elbow with the UCL, and the two conditions can coexist. When medial elbow pain is prominent in an overhead athlete, a elbow MRI is often needed to determine whether symptoms are coming from the flexor tendon, the UCL, or both.

Causes

Lateral epicondylitis (tennis elbow)

Despite its name, the majority of tennis elbow cases occur in people who do not play tennis. Any repetitive gripping, wrist extension, or forearm rotation activity can overload the common extensor origin — including keyboard use, painting, plumbing, carpentry, and gardening. In tennis players specifically, poor backhand technique is a well-established risk factor.

Medial epicondylitis (golfer's elbow)

Repetitive wrist flexion and forearm pronation — as occurs in golf, throwing sports, racquet sports, and heavy manual labor — overloads the common flexor-pronator tendon origin at the medial epicondyle. It is less common than lateral epicondylitis but more frequently associated with concurrent ulnar nerve irritation.

Symptoms

Lateral epicondylitis presents as pain and tenderness over the outer elbow, worsening with gripping, lifting, and wrist extension. Shaking hands, turning a doorknob, or lifting a coffee cup can provoke symptoms. Medial epicondylitis causes pain on the inner elbow, aggravated by wrist flexion and forearm pronation. In both conditions, pain typically builds gradually and may persist for months to years without proper treatment.

Diagnosis

Diagnosis is primarily clinical, based on the location of tenderness and provocative testing. However, when symptoms are severe, persistent, or atypical — or when a partial tendon tear is suspected — MRI provides important information that examination alone cannot.

A dedicated elbow MRI can quantify the degree of tendon degeneration, identify partial or complete tendon tears, detect bone marrow edema at the epicondyle, and assess for concurrent pathology such as UCL involvement or ulnar nerve compression — all of which influence treatment decisions.

Grading

• Grade 1: Tendon signal change without structural disruption (pure tendinopathy).
• Grade 2: Partial thickness tearing of the tendon — fibers disrupted but tendon maintains attachment.
• Grade 3: Complete or near-complete tendon avulsion from the epicondyle.

Treatments

The vast majority of epicondylitis cases resolve with non-surgical treatment, though recovery can be prolonged.

Initial and conservative management: Activity modification, counterforce bracing (tennis elbow strap), physical therapy emphasizing eccentric strengthening and stretching, NSAIDs, and ice. Most patients improve significantly over 3–6 months with a consistent conservative program. Corticosteroid injection can provide short-term pain relief but does not improve long-term outcomes and may weaken tendon tissue with repeated use.

Refractory cases in active patients

For patients who fail 6 months of conservative management, options include platelet-rich plasma (PRP) injection — which has growing evidence for tendinopathy — extracorporeal shockwave therapy (ESWT), and surgical debridement or release of the affected tendon origin. Surgical outcomes are generally good, with most patients returning to full activity within 3–6 months of the procedure.

Grade 3 tears and complete avulsions

Full-thickness tendon avulsions are less common but typically require surgical reattachment, particularly in patients with significant functional demands on the elbow.

Related Elbow Conditions

• UCL Tear
• Osteochondral Defect of the Elbow
• Biceps Tendinopathy / Biceps Tear
• Olecranon Bursitis
• Back to all Elbow Conditions

Olecranon bursitis is inflammation and fluid accumulation within the olecranon bursa — a small, fluid-filled sac that sits over the bony tip of the elbow (the olecranon). Under normal conditions the bursa is flat and nearly invisible, but when inflamed it can expand dramatically, producing a visible, egg-shaped swelling at the back of the elbow.

While olecranon bursitis is often straightforward to diagnose clinically, MRI becomes important when there is concern for infection (septic bursitis), an underlying osteochondral or bony abnormality, or when the diagnosis is uncertain. In cases of trauma to the posterior elbow, concurrent distal triceps tendon injury should also be considered.

Causes

Traumatic causes

A direct blow or fall onto the tip of the elbow is one of the most common triggers, causing acute bleeding into the bursa. Repeated low-grade trauma — such as chronically leaning on a hard surface — is equally common and produces a gradual accumulation of fluid over time. This pattern is so prevalent in certain occupations that olecranon bursitis has historically been called "student's elbow" and "miner's elbow."

Inflammatory and infectious causes

Systemic inflammatory conditions such as rheumatoid arthritis and gout can cause olecranon bursitis as part of a broader joint involvement pattern. Septic (infected) bursitis occurs when bacteria enter the bursa — most commonly through a skin break overlying the olecranon — and represents the most urgent form of the condition, requiring prompt diagnosis and treatment.

Symptoms

The primary finding is a soft, fluctuant swelling at the tip of the elbow that may be surprisingly large. In non-infected cases, the swelling is often painless or only mildly tender, and elbow range of motion is preserved. Septic bursitis, by contrast, presents with significant pain, warmth, redness, and tenderness over the bursa, often accompanied by fever and systemic signs of infection. Gout-related bursitis may feature similar redness and extreme tenderness.

Diagnosis

Clinical examination is usually sufficient to identify olecranon bursitis. The key diagnostic challenge is distinguishing septic from non-septic bursitis — bursal aspiration with fluid analysis (cell count, culture, and crystal examination) is the definitive test when infection or gout is suspected.

When the diagnosis is uncertain, when a bony or soft tissue abnormality is suspected, or when the bursa fails to resolve with initial treatment, a dedicated elbow MRI provides detailed information about bursal wall thickening, the presence of internal debris or septations, adjacent bone and tendon integrity, and any signs of deeper infection extending beyond the bursa itself.

Classification

• Traumatic / non-inflammatory: Fluid accumulation without significant wall thickening or systemic signs; the most common and benign form.
• Inflammatory (gout, rheumatoid): Bursal thickening and inflammation associated with systemic disease; may contain crystals or pannus tissue.
• Septic (infected): Bacterial infection of the bursa requiring urgent aspiration and antibiotic treatment; the bursa wall is typically thick and irregular on MRI.

Treatments

Treatment is tailored to the underlying cause.

Non-septic traumatic bursitis: Padding and protection of the elbow to prevent further irritation, activity modification, compression wrapping, and NSAIDs. Aspiration of the bursa can reduce swelling rapidly, and corticosteroid injection may be added to reduce the chance of recurrence. Most non-infected cases resolve with conservative management, though the bursa can refill and recurrence is common if the provocative activity continues.

Septic bursitis

Infected olecranon bursitis requires urgent aspiration and culture-directed antibiotic therapy. Mild infections can often be managed with oral antibiotics and close outpatient follow-up, while more severe or non-responding cases require intravenous antibiotics and surgical drainage or bursectomy (removal of the bursa).

Chronic or recurrent bursitis in all patients

When bursitis recurs repeatedly despite conservative measures, surgical bursectomy — removal of the entire bursa — provides a definitive solution. The bursa regenerates over several months after surgery, but the new tissue is typically thin and does not re-accumulate fluid. Recovery after bursectomy usually takes 4–6 weeks.

Related Elbow Conditions

• UCL Tear
• Osteochondral Defect of the Elbow
• Biceps Tendinopathy / Biceps Tear
• Epicondylitis (Tennis Elbow / Golfer's Elbow)
• Back to all Elbow Conditions