• Mallet finger of tendon origin.
• Mallet finger of bony origin.
This is thanks to loss of extensor tendon continuity at the distal finger joint.
Mechanism of Injury
Here the top of the finger is forcibly flexed, when extensor tendon is taut, e.g. while tucking the bed, catching a ball, striking an object with extended finger, etc.
Pain, swelling, tenderness, flexion deformity of the tip of the finger and inability of the patient to actively extend the finger at the distal PIP joint.
The following deformities might be seen supported the kinds of injuries.
• Extensor tendon stretched during this , degree of drop is a smaller amount . there’s loss of 5 to 20° of extension. there’s weak active extension.
• Extensor tendon is ruptured from its insertion into distal phalanx. there’s 40 to 45° loss of extension. No active extension.
• Avulsion fracture. alittle fragment of distal phalanx is avulsed with the extensor tendon. there’s no active extension and it should be treated as tendon injuries instead of fractures. If the flexion deformity is severe, a secondary hyperextension deformity of PIP joint occurs, due to imbalance of the extensor mechanism.
X-ray of the affected finger may show an avulsion fracture of the dorsal lip of the bottom of the distal phalanx.
|Mallet Finger X-ray|
Nonoperative measures: this is often reserved for pure dislocations, collateral ligament injuries and mallet finger. Various custom-made dorsal hyperextension splints (Mallet splints) are used for immobilizing the DIP joints.
Closed reduction and percutaneous fixation: this is often reserved for mallet injuries in professionals like dentists, surgeons, sportspersons, etc. who cannot keep their fingers immobilized for long thanks to professional commitments.
Open reduction and internal fixation: this is often indicated within the following situations:
• Avulsion of the profundus tendon and its reinsertion.
• Chronic subluxation of the DIP joint (> 3 wks).
• Irreducible dislocations.
Mallet Finger of Bony Origin
This is less common. it’s usually fixed with K-wire, if quite one-third of the dorsal articular surface is involved and if remainder of the distal phalanx is subluxated volar-wards.
Facts about Mallet Splints
In these cases, proximal hinge joint of the finger isn’t immobilized but only the distal joint is immobilized by using:
a. simple volar unpadded aluminum splint is used, which provides three-point pressure.
b. Dorsal padded aluminum splint.
c. A stack plastic mallet finger splint Distal joint is put in slight hyperextension. The splint may cause pain and therefore the amount of hyperextension shouldn’t cause blanching of the heal DIP joint. Splints are useful in cooperative patients, and in uncooperative patients. Smellie’s cast is employed . About 6 to 10 weeks of continuous immobilization is required. K-wire fixation is taken into account in patients like dentist or surgeon who wants to return to figure quickly.
Lesser-Known but Important Thumb Injuries
• Bowler’s Thumb: it’s a traumatic neuropathy of the digital nerve of the thumb thanks to repeated friction from gripping a ball.
• Game Keeper’s or Baseball Thumb: This has been explained earlier.