Sprained thumb is comparatively a common condition that is a result of damage or tearing of the ligaments, joint capsule and cartilage of the thumb.
The thumb consists of two little bones called phalanges. These phalanges stick together at the interphalangeal joint(1) and to the thumb side bone of the palm i.e. first metacarpal at the metacarpophalangeal joint developing two joints for the thumb. These joints individually consist of strong connective tissue covering around the bone ends and cartilage that lies between the surfaces of joints reducing the impact of the bones on each other while performing regular activity.
Compression or stretching forces get placed on the joints of the thumb when the thumb performs certain movements. Excessive forces such as overuse or heavy force leads to the joint injury, which may result in damaging the cartilage or tearing ligaments or joint capsule. This condition is called as a sprained thumb, which may also affect interphalangeal joint or metacarpophalangeal joint.
Sprained thumb is suffered in contact sports such as rugby and ball sports such as basketball and netball, but is more common in skiing and hence is also known as skier’s thumb.
Types of Sprained Thumb or Skier’s Thumb
Sprains are classified into three types depending upon the condition of the injury or damage to the ligaments. They are as follows:
- First degree as mild.
- Second degree as moderate.
- Third degree as severe.
First Degree Sprained Thumb or Skier’s Thumb:(2) This is mild in nature. In this type, ligaments are overstretched, but they do not tear. Pain and localized swelling around the injured joint could be experienced by an athlete. The ability of an athlete to extend and flex the affected thumb becomes limited because of the presence of swelling inside the joint. Generally the strength of the thumb remains unaffected. The ligament remains tight and the joint remains stable when the stability test is performed to the injured joint. Joint movements may exacerbate the athletes discomfort and pain.
Second Degree Sprained Thumb or Skier’s Thumb: This is a moderate type of sprain. This type of strain has a strong impact on ligaments as well as the joint capsule. Not only damage but also partial tearing of the ligament and joint capsule takes place due to stronger force of injury. This type of sprain may also result in hyperextension or excessive extension of the joint beyond its normal range due to torn ligament.
Pain and swelling are significant symptoms in this type of injury. The swelling may be felt all over the thumb within the starting few hours and could probably limit the range of motion of the thumb. Tenderness of the joint will also be experienced specifically on touching over the injury site. The athlete may also experience instability of the thumb, which poses a great challenge with function to a large extent as the thumb is the most functional of all digits.
Third Degree Sprained Thumb or Skier’s Thumb: This is the most severe type of sprain. This kind of sprain often results in a total rupture of the ligament. A complete ligament rupture occurs not only at its attachment, but also in its middle area. The ligament rupture sometimes pulls away the bone from the distal attachment which could cause an avulsion fracture.
A third degree Sprained Thumb or Skier’s Thumb could also lead to the subluxation. A subluxation(3) is characterized as a partial dislocation in the thumb that reduces itself. This occurs discreetly without the athlete realizing it.
A dislocation could occur in some cases, which is realized by an athlete due to the pain and apparent deformity of the thumb. The initial reaction of the athlete is to reduce the dislocation immediately pulling on to the thumb. This has to be followed by splinting and x-ray for proper treatment and to rule out a fracture.
The result of a third degree sprain may be instability and laxity of the thumb with severe pain, swelling, and probable discoloration.
Causes of Sprained Thumb or Skier’s Thumb
- Hyperextension force or a sideways force could cause a Sprained Thumb or Skier’s Thumb.
- A Sprained Thumb or Skier’s Thumb may also be caused by repetitive strain related to overuse. This happens when an individual performs repetitive activities which involve continuous movement of the thumb.
- Sprained thumbs are particularly common in contact sports and ball sports like netball, baseball, basketball or martial arts.
- A sprained thumb also occurs frequently in skiing where one of the hand poles may forcibly push the thumb backwards.
- A Sprained Thumb or Skier’s Thumb also occurs in hockey players with the mechanism similar to that of skiing.
- Football players can also sustain Sprained Thumb or Skier’s Thumb specifically while tackling an opponent.
- Catching a thumb in a jersey or any other piece of sports equipment is also a mechanism of sports injury leading to Sprained Thumb or Skier’s Thumb.
Signs and Symptoms of Sprained Thumb or Skier’s Thumb
- Sudden onset of pain in the thumb at the time of injury.
- Pain is experienced while bending the thumb in backward direction.
- A pop sound or an audible snap at the time of injury could also be experienced.
- Bruising or swelling around the affected joint.
- The back or front sides of the affected joint of the thumb may reflect the symptoms.
- Pain is felt in the web of the thumb during movement.
- Feeling of stiffness and pain after the provocative activity especially the next morning.
- Dislocation of the thumb could also occur in some severe cases.
- Swelling over thumb joint at the bottom.
- Weakness in the thumb and hand.
- Pain on firmly touching the affected area.
- Instability and laxity in the joint may involve complete rupture of ligaments.
- Activities which involve use of thumb and fingers like opening jars, picking up objects, cooking, household chores, etc increase symptoms.
Treatment for Sprained Thumb or Skier’s Thumb
The mainstay of treatment for Sprained Thumb or Skier’s Thumb is good rest and to stop doing activities that provoke symptoms until it is completely healed. Protective bracing is done for stabilization of joint and prevent greater damage. RICE protocol is followed. Antiinflammatories are used for pain and swelling.
Physical Therapy: It is an important component since it speeds up recovery and reduces instances of future occurrences.
Physical Therapy (PT) for Sprained Thumb or Skier’s Thumb May Include:
- Joint mobilizations.
- Soft tissue massages.
- Heat or ice.
- Improve strength with exercise.
- Modifications of lifestyle.
- Returning to activity in moderation.
Exercises for Sprained Thumb or Skier’s Thumb
Thumb Apposition: This is done by trying to move thumb to every fingertip starting with index finger and ending with little. If the thumb cannot touch the fingertip, try and get as close as possible until there is a painless stretch sensed. This needs to be repeated 10 times without increasing symptoms.
Thumb Extension-Flexion:(4) This is done by moving the thumb away from fingers as much as it can be moved until there is a painless stretch sensed. Again, it should be repeated 15 times without increasing symptoms.
Tennis Ball Squeeze: To do this type of exercise, a spongy substance is used and squeezed the hardest possible way without pain exacerbation for about 10 seconds and repeated about 5 times.
Investigations for Sprained Thumb or Skier’s Thumb
A detailed examination is conducted to look for damaged structures other than the affected thumb. Other tests are:
- CT scan.