Definition of thumb sprains:
The sprained thumb is one of the most frequent hand injuries in sports. The injury typically results from a fall onto the thumb, with the hand open; cracking may be felt or even heard. Acute thumb pain ensues, with swelling, and sometimes a haematoma of the hand and thumb. Thumb sprains are very frequent as a result of falls in skiers or skaters but they can be found in almost all sports.
This thumb injury corresponds in most cases to the lesion of a ligament in the metacarpophalangeal joint (MCP).
Video of arthroscopic treatment of a thumb sprain:
Thumb sprain diagnosis:
The clinical examination is the best examination; it should be bilateral and comparative and look for laxity of the metacarpophalangeal thumb joint in the frontal plane (valgus-varus) When no laxity is found, a medical treatment consisting in immobilization (bespoke orthosis) for a month will be sufficient.
If the thumb is lax at the metacarpophalangeal joint, articular hand surgery will be necessary to repair the thumb’s ligaments.
An x-ray of the thumb must always be performed to look for a palmar subluxation of the MCP or a corner fracture of the phalanx which corresponds to a tearing of the ligament at the bone. When a displaced fracture with tearing is found, thumb surgery is required. In case of diagnostic doubt, an ultrasound scan of the hand focusing on the thumb’s ligaments can prove useful; this test will look for a Stener lesion, in particular, that is to say an avulsion of the medial collateral ligament that passes over the of the thumb’s extensor apparatus.
Hand surgery will thus be justified:
- if there is a displaced fracture with a rupture (avulsion)
- if there is articular laxity of the thumb’s MCP
- if there is a Stener lesion
Benefit of arthroscopy in thumb sprain surgery:
For sprained thumbs, arthroscopy has many benefits:
1. diagnostic benefits: arthroscopic thumb sprain surgery is the only technique allowing a 360° evaluation of the ligaments’ lesions, while with open surgery, these can only be examined on one side of the thumb. Conversely, thumb arthroscopy makes it possible to evaluate anterior, median and lateral lesions.
2. therapeutic benefits:
- the extensor apparatus and the dorsal aponeurosis are spared
- joints bleeding and inflammatory synovial fluid can be evacuated
- precise surgical repair of each of the thumb’s ligaments is made possible by placing one anchor or more.
- arthroscopy greatly helps reducing scars.
All of these factors facilitate the recovery of the thumb and the convalescence of the hand.
Arthroscopic thumb sprain surgery:
This hand surgery is performed under regional anaesthesia, on an outpatient basis. The hand is put under slight traction applied along the thumb’s axis. Only two 2-mm incisions will be performed. The 1.9 mm arthroscope (camera) is inserted through a posterior portal and a lateral instrumental portal allows joint bleeding and the inflamed synovial membrane to be evacuated.
The surgical procedure begins with a complete assessment of the damage to the capsule and ligament of the thumbs’s joint.
Once the rupture of the collateral ligament has been identified, a screw-in anchor can be inserted in the base of the thumb’s phalanx.
Using a common “shuttle relay” arthroscopic surgery technique, each of the strands can be passed in the ligament of the thumb to be repaired.
Traction is then released to tie the knots together and thus reattach the damaged collateral ligament of the thumb.
Surgical incisions do not require any stitches. One week after surgery, the dressing can be permanently removed. Immobilization by bespoke thumb orthosis must be kept for 3 weeks.
Recovery after arthroscopic surgery on sprained thumb
The hand dressing can be removed after one week. The thumb must be immobilized for 3 weeks, daily tasks using the thumb can resume right after the orthosis is taken away.
Specialized hand rehabilitation is not always necessary.
Avoid forceful movements with your hand (>1,5 kg) for 2 months. Typically, the thumb is slightly sore and there is discomfort in constrained movements for almost 3 months. To resume rugby, the hand and the thumb will require taping at the beginning.