Thumb Sprain: Symptoms, Causes & Treatment Plan

A stable thumb is very important for your pinch & grasp activities. A sprained thumb is a painful condition caused due to an injury or damage to the main ligament (ulnar collateral ligament) connecting the bones at the base of your thumb. The ulnar collateral ligament (UCL) might get partially or completely tear due to extreme backward bending of your thumb. Usually it is very common among basketball, rugby & football players. If your sprained thumb is not treated properly, it may eventually lead to develop muscle weakness, joint stiffness, scar tissue formation or even early arthritis.

Thumb Sprain Classification:

Thumb sprain can be classified according to the extent of the injury –

• Grade 1 (mild) injuries – microscopic tearing of the fibers in the ligament but there is no loss of ligament continuity.

• Grade 2 (moderate) injuries – it involves partial torn of the ligament from the bone. There is some loss of thumb function.

• Grade 3 (severe) injuries – completely ruptured of the ligament or ligament separates from the bone. Surgery is needed for ligament repair.

Causes:

The most common causes of your thumb sprain are following –

• Hyperextension force – a force which makes bending your thumb backwards away from the normal position.

• Hyperflexion force – a force which makes excessive forward bending your thumb beyond its movement limit.

• If you fall onto your thumb.

• If you fall on an outstretched hand.

• Chronic repetitive excessive pressure on your thumb.

• Punching without a closed fist.

• If a ball hits the tip of your thumb.

Risk Factors: The main risk factors for thumb sprain are –

• Basketball, netball.

• Contact sports like as rugby, hockey, football.

• Skiing.

• Martial arts.

Symptoms:

• Instant sharp pain at the base of your thumb.

• You may notice swelling in the web space at the base of thumb which last for up to a week after injury.

• Bruising around your thumb which is common during acute stress sprain.

• Pain is increased during thumb / hand activity.

• Your thumb movements will be impaired.

• You might have trouble performing your daily activities such as writing or holding a glass.

• Weakness of your thumb – index pinch.

• In severe cases joint laxity & instability can be seen.

Diagnosis:

It is strongly advised to consult with your physician for an early diagnosis & treatment of your thumb sprain. Your doctor will examine the thumb by moving your thumb in different position to determine whether the ligament is torn and to test the MCP joint stability. Your doctor will also ask you about the history of the injury & symptoms. Your physician may order a stress X - ray or MRI (magnetic resonance imaging) to rule out a thumb fracture or dislocation.

Treatments:

Conservative treatment – it is appropriate for a partial or mild ligament thumb sprain cases. Grade 1 & 2 types of your thumb sprain injuries can be treated by conservatively.

Rest the thumb: You will need to rest the thumb for the first couple of day to keep the sprain from getting worse.

Apply ice compress – You should apply a ice pack or gel pack on the area of sprain as soon as possible after injury to reduce pain & swelling twice a day for up to 20 minutes at a time during the 48 hours.

Use of splint or cast – You will need to wear a thumb spica splint or cast of the joint at all times for the first 3 weeks to keep it from moving while it heals.

Medication – You will take over – the – counter drug or NSAID like acetaminophen, ibuprofen which can help to ease pain & inflammation & decrease swelling. These medications also help to speed up the natural healing process.

Wear a wrap – You will need to wear a wrap or thumb brace which can restrict your thumb movement & also provide much needed stability to the muscles & joints.

Elevate the thumb – It is also advised to keep your thumb in an elevated position higher than your heart to promote fluid drainage from the affected region.

Surgical Treatment:

Surgical intervention is required if there is a chronic UCL injury & severe or total rupture of the UCL ligament or avulsion fracture in your thumb. It helps to reconnecting the injured ligament with the bone or repairing the fracture by a pin, screw or special bone anchor. It should be performed within 3 weeks after injury to ensure maximum results. You may need to wearing a splint or short arm cast on the thumb for a few weeks following the surgery to protect the thumb ligament while it heals.