Hand, Wrist, and Elbow: The Ambulatory Soft-Tissue Lineup

The Epicondyle Split: Two Origins, One Reflex

Lateral epicondylitis is the extensor carpi radialis brevis origin; medial epicondylitis is the flexor-pronator origin. The resisted motion that reproduces the pain names the tendon, and the ulnar nerve check belongs to every medial elbow.

Lateral epicondylitis is a tendinopathy of the common extensor origin, and the tendon that carries the disease is the extensor carpi radialis brevis. It hits the 35 to 55 age band and follows repetitive wrist extension: racquet sports, hammering, lifting with the wrist cocked. The pain sits over the lateral epicondyle and radiates down the extensor forearm with gripping and handshake.

The test that proves it is resisted wrist extension with the elbow extended, the Cozen test, which reproduces the exact pain. Resisted long finger extension does the same, because the ECRB shares that load. Medial epicondylitis is the mirror: the flexor-pronator origin, fired by resisted wrist flexion and pronation in golfers, pitchers, and throwers.

One check belongs to every medial-sided elbow: the ulnar nerve. Cubital tunnel symptoms can ride with, or masquerade as, golfer elbow, so test the ring and little fingers before you inject. That crossover lives in the nerve palsies deep dive.

Flip between the two epicondyles and hold the reflex.

De Quervain Tenosynovitis: Two Tendons in a Too-Tight Tunnel

The abductor pollicis longus and extensor pollicis brevis share the first dorsal compartment at the radial styloid. When the sheath stenoses, the radial wrist fires on Finkelstein, and the classic patient is a new mother.

The first dorsal compartment is a tunnel at the radial styloid holding two tendons: the abductor pollicis longus and the extensor pollicis brevis. Repetitive thumb and wrist use thickens the sheath, the tendons bind, and the pain lands on the radial side of the wrist, worse with gripping, turning keys, and lifting a baby.

The maneuver that names it is Finkelstein: fold the thumb into the fist and deviate the wrist ulnarly. The stretch of both tendons against the stenosed sheath reproduces the pain over the radial styloid. New mothers are the classic patients: hormonal change plus the wrist-extended, thumb-abducted lift of a growing baby overloads the compartment, and so do workers who pinch and twist all day.

Treatment starts with a thumb spica splint and activity modification, then a corticosteroid injection into the first dorsal compartment. Refractory disease gets a surgical release of the compartment roof, and the tendon anatomy is why the surgery must protect the radial sensory nerve branches.

Run the new mother case with hints before the answer.

Trigger Finger: The A1 Pulley That Won't Let Go

Stenosing tenosynovitis of the A1 pulley: a nodule over the metacarpal head, a finger that locks in flexion and snaps open, a diabetes association, and a fixed ladder from injection to release.

The flexor tendons of a finger run through a series of pulleys, and the A1 pulley at the metacarpal head is the door. When the tendon and its sheath thicken, the door narrows, a nodule forms in the palm, and the finger catches: it locks in flexion and snaps open with a trigger release. The ring and middle fingers and the dominant hand are the usual suspects.

Diabetes is the association boards plant most: it roughly triples the risk, and it belongs to the diabetic hand quartet: trigger finger, carpal tunnel syndrome, Dupuytren contracture, and limited joint mobility, all fed by collagen glycation in poorly controlled disease. A hemoglobin A1c in the 8s on a trigger finger stem is the cue to manage the glucose along with the hand.

The ladder is fixed. Mild disease gets activity modification and an MCP-blocking splint. Locking earns a corticosteroid injection into the flexor sheath at the metacarpal head, which resolves most cases and can be repeated once.

Persistent locking goes to surgery: division of the A1 pulley, open or percutaneous.

Put the trigger finger treatment ladder in order.

Dupuytren Contracture: The Palmar Cord That Bends the Ring Finger

Palmar fascial cords, ring finger first, MCP before PIP, and the PIP contracture that drives surgery. The table-top test is the one-screen exam, and the ectopic fibromatoses complete the picture.

Dupuytren contracture is a disease of the palmar fascia: nodules and cords of collagen that tether the fingers into flexion. The ring finger is the classic first victim, then the little finger, and the cord runs from the palm to the digit like a tightening bowstring. Northern European ancestry, male sex, age, alcohol, diabetes, epilepsy, and smoking fill out the risk list.

The contracture arrives in order: MCP first, PIP second, and the PIP is the joint that matters. A PIP contracture drives functional loss and is the indication for intervention, while isolated MCP disease can be watched. The table-top test is the one-screen exam: if the hand cannot lie flat, the disease is past mild.

The same fibrous process appears elsewhere as the ectopic fibromatoses: Garrod pads over the knuckles, Ledderhose disease in the plantar fascia, and Peyronie disease of the penis. Mild disease is observed; a positive table-top test or a PIP contracture earns needle aponeurotomy or fasciectomy, and recurrence is common enough that the patient keeps follow-up.

Tap each letter to reveal the association it holds.

The Thumb UCL: Skier's Thumb and the Stener Lesion

The ulnar collateral ligament of the thumb metacarpophalangeal joint tears under valgus stress. If the torn end retracts above the adductor aponeurosis, it is a Stener lesion, and splinting is futile.

The thumb MCP joint is stabilized on its ulnar side by the ulnar collateral ligament. Chronic repetitive stress loosens it in gamekeeper's thumb; an acute valgus force, classically a fall onto an outstretched hand with the thumb caught in a ski pole strap, tears it in skier's thumb. The joint swells, hurts, and buckles under valgus stress.

Stress the MCP in slight flexion: laxity more than 30 degrees, or more than 15 degrees beyond the other thumb, marks a complete tear. Then feel the ulnar edge of the joint, because a small lump proximal to it is the torn ligament end that has retracted above the adductor pollicis aponeurosis: the Stener lesion. The aponeurosis now sits between the torn ends, so the ligament cannot heal, and splinting is futile.

That is the entire management question. A non-displaced tear is splinted in a thumb spica for 4 to 6 weeks and heals. A Stener lesion goes to the operating room for reattachment, and the longer it waits, the more the stump retracts and the worse the repair.

Which door does the exam open?

Three Finger Drops: Mallet, Boutonniere, and Jersey Finger

Three injuries, three postures, three tendons: the terminal extensor at the DIP, the central slip at the PIP, and the flexor digitorum profundus avulsing from the distal phalanx. Read the joint that will not move.

Mallet finger is a drop of the fingertip: the terminal extensor tendon avulses, often when a stubbed fingertip takes an axial load, and the DIP loses active extension. The treatment is the splint: a full-time DIP extension splint for 6 to 8 weeks, night wear included, because one flexed episode restarts the gap. An untreated mallet can remodel into a swan-neck, PIP hyperextension with DIP flexion.

Boutonniere is the middle-joint drop: the central slip of the extensor mechanism tears at the PIP, the lateral bands slip volar and become flexors of the PIP and extensors of the DIP, and the finger lands in its signature posture: PIP flexed, DIP hyperextended. The PIP is splinted in full extension for about 6 weeks, and the posture is the diagnosis.

Jersey finger is the flexor drop: the flexor digitorum profundus avulses from the distal phalanx, classically the ring finger grabbing an opponent jersey, and the fingertip cannot actively flex. The tendon retracts along the sheath, so repair is urgent surgery, and the clock matters (see the FDP anatomy in the forearm flexors deep dive).

Match each finger posture to the tendon injury.

When Hand Pain Is a Nerve: Carpal Tunnel, Cubital Tunnel, or the Neck

Numbness patterns localize the lesion: the median nerve at the wrist, the ulnar nerve at the elbow, or a cervical root. The named signs and the reflex changes split them.

Carpal tunnel syndrome is the median nerve at the wrist: numbness in the thumb, index, and middle fingers, night pain that shakes out, and, late, thenar wasting with weakness of thumb abduction and opposition. Tinel and Phalen tests provoke it, and treatment runs from night splinting to injection to release (see the nerve palsies deep dive).

Cubital tunnel syndrome is the ulnar nerve at the elbow: ring and little finger numbness, elbow flexion provocation, and two named signs. Wartenberg: the little finger sits abducted and cannot adduct. Froment: the thumb IP joint flexes during pinch because the adductor pollicis is weak and the flexor pollicis longus takes over.

When the symptoms do not fit one nerve, look up. C6 tingles the thumb and index with a biceps reflex change, C7 takes the middle finger and triceps, and C8 takes the ring and little fingers with intrinsic hand weakness (see the cervical radiculopathy deep dive). Neck pain, a Spurling sign, or a pattern that crosses nerves points to the spine.

Localize the lesion.

The One-Screen Discriminator: Digit, Motion, Test, and the Red Flags

Every stem in this lineup answers three questions: which digit or joint, which motion is lost or hurts, and which test fires it. Then run the red flags, led by Kanavel's four signs.

Run the reflex in order. Which digit or joint? Elbow, radial wrist, thumb MCP, or a finger joint.

Which motion is lost or hurts? Resisted extension says epicondyle; the fist-and-ulnar-deviation says de Quervain; locking says the A1 pulley; valgus buckling says the thumb UCL; the joint that will not move says the tendon that tore.

Which test fires it? Cozen, Finkelstein, the table-top test, the valgus stress test, and active DIP flexion each name their own diagnosis.

Then run the red flags. A locked flexed digit with fusiform swelling, tenderness along the whole sheath, a semiflexed posture, and pain on passive extension is septic flexor tenosynovitis, not trigger finger, and it is a surgical emergency (see the MSK infections deep dive).

Numbness that follows a nerve pattern is the nerve section. An inability to extend is the extensor mechanism. The four signs below are the discriminator between the benign lock and the infected sheath, and the boards expect them in order.

Tick Kanavel's four signs as you examine a locked finger.

Run the epicondylitis injection decision tool.