Hand and Finger Injuries

Distal fractures

Fractures of the metacarpal shaft

• In transverse fractures, there is usually dorsal angulation due to traction by the interosseus muscles
• Fracture angulation is not acceptable in second and third finger metacarpal bones. For the fourth and fifth fingers, < 20° and < 30° angulation, respectively, is acceptable.
• Oblique fractures often lead to a rotational malposition, which must be corrected. Any rotational error must be reassessed after possible reduction.
• Shortening of less than 5 mm in a fracture normally causes no functional problems.
• Fissure fractures are stable. They can be treated by splinting for 1-2 weeks.
• If reduction is necessary, a splint should be used for 3-4 weeks.
• The position of all fractures should be assessed by x-ray immediately after reduction and 1 week later. Repeat x-ray at 2 weeks should be performed as considered appropriate.
• If necessary, a hand or orthopaedic surgeon should be consulted about operative repair if the position is unacceptable after reduction.

Proximal fractures

• Fracture type and position may be difficult to assess reliably in plain x-ray; CT should be used, as necessary.
• Proximal intra-articular fracture of MC V, possibly associated with (sub)luxation of the CMC V joint is the most common. The fracture is often unstable and its treatment operative.

Fracture of the metacarpal shaft

• Conservative treatment is usually successful.
• Reduction, as necessary; angulation of up to 15-20° in the AP direction or 20-30° laterally is acceptable because the great mobility of the proximal thumb joint (CMC1) compensates for the malposition.
• A well-aligned fracture can be treated by applying a cast from the proximal lower arm to above the IP joint of the thumb (leaving the IP joint free) for 5 weeks.

Fracture of the metacarpal base

• Typically an intra-articular fracture of the base of the first metacarpal thumb bone (Bennett's fracture). The ulnar fracture fragment remains in situ but the rest is often (sub)luxated (Image ).
• Radiographic diagnosis and assessment of fracture alignment requires at least PA, oblique and lateral projections.
• In Bennett's fracture, conservative treatment is possible if the step-off on the joint surface is < 1 mm.
  • The first MP joint should be placed in a cast at 30° of flexion; it should be noted that during reduction and casting the MP joint should not be overextended.
  • The thumb IP joint should be left free of cast.
  • Follow-up x-rays should be done at 1 and 2 weeks; time in cast 6 weeks.
• To reduce a Bennett's fracture, draw the thumb distally while pressing the base of the metacarpal bone into adduction and its distal end into abduction (Image ). A dislocated Bennett's fracture often needs surgical treatment because even after successful reduction the position is often not stable.
• An intra-articular comminuted fracture at the base of the first metacarpal bone (Rolando's fracture) is often treated operatively.

Distal phalanx fracture

• Mallet fracture: injury to the extensor tendon in the distal phalanx (see below Tendon injuries here)
• Jersey finger: an avulsion injury of the flexor tendon including the detachment of a piece of bone at the tendon insertion. The injury requires operative treatment.
• Tuft (the wide part of the distal phalanx) fracture is often due to compression. Splinting for 1-2 weeks to treat pain is often sufficient to treat the fracture but soft tissue damage is often more significant for the choice of treatment than the fracture.
• A well-aligned transverse fracture can be treated with a short splint placed for 1-2 weeks; a dislocated distal phalanx fracture may require surgical treatment.
• Any damage to the germinal matrix should be noted and repaired by stitching, as necessary.

Middle and proximal phalanx fractures

• These often present with angulation, shortening or rotational displacement. They should be treated according to the general principles of finger fractures.
• Fractures extending to the joint surface are often unstable, and should be treated conservatively only if there is no step-off on the joint surface or no axial or rotational error in the movement range of the finger.
• Follow-up imaging should be performed at 1 and 2 weeks.
• The PIP joint can easily become stiff from injury or immobilization, and injuries should therefore be treated by mobilization as early as possible. In the treatment of a small fracture fragment on the volar joint surface of the middle phalanx, for example, the finger should be rapidly mobilized, except if the damage to the joint surface is so extensive that the joint will not remain stable. Fractured luxation of the PIP joint is often problematic, and a hand surgeon should be consulted.
• Reduction and stabilization of a malaligned proximal phalanx fracture can usually be successfully achieved by flexing the MP joint 80-90°.
• It is important to get acceptable x-ray pictures at baseline and at every repeat x-raying. A true lateral radiograph is necessary and oblique radiographs are useful. If adjacent fingers appear on top of each other in the lateral projection, the other fingers can be slightly flexed or extended out of the projection line.

PIP joint

• WhenPIP ligament injury is suspected, the joint should be examined by testing lateral stability and overextension, and by observing whether the joint stays in place in active flexion-extension.
• Finger PIP ligament injuries are primarily treated by immediate mobilization, using a buddy strap or splint for 1-2 weeks, after which a buddy strap can be used to support mobilization, as necessary.
• PIP joint luxation is typically dorsal.
  • Reduction should be done immediately when you see the patient because it is best done when the injury is recent.
  • Digital block of the finger should be used as necessary and for delayed reduction.
  • Apply distal traction to the finger while bringing the dislocated joint into place.
  • Overextension of the PIP joint combined with traction may help in reduction if the joint is completely dislocated (bayonet dislocation).
• After reduction, examine active flexion and extension of the finger and take an x-ray to confirm that the joint is in place, as well as to detect any fractures.
• If the joint stays in place, the follow-up treatment of dorsal luxation consists of immediate mobilization in a buddy strap for 1-2 weeks.
• Volar PIP joint luxation is rarer and often associated with a central slip injury, which untreated will lead to a permanent finger (buttonhole) deformity.
• If closed reduction is unsuccessful, the joint will not stay in place or an associated extensor tendon injury is suspected, a hand surgeon or orthopaedist should be consulted about the treatment.
• After luxation or ligament injury, the finger may be sore and swollen for up to one year.

MP joint

• Complete rupture of the ulnar collateral ligament (UCL) of the thumb MP joint should be treated operatively (see below).
• Minor MP ligament injuries of fingers II-V can be treated conservatively; in the case of complete rupture, surgical treatment can be considered.
  • Conservative treatment consists of immobilization with the MP joint in 30° of flexion for 3 weeks and subsequent mobilization in a buddy strap, as necessary.
• MP joint subluxation in fingers II-V is usually dorsal. An asymmetric joint space can be seen on x-ray. The volar plate is often in the joint space and the MP joint therefore overextended.
  • In the reduction of MP joint subluxation, no traction should be applied to the finger and the joint should not be further overextended because this would probably cause total luxation.
  • For reduction, first flex the wrist to reduce tension on the flexor tendons, and push just the base of the proximal phalanx into place (the proximal phalanx will slide along the joint surface of the metacarpal bone).
  • Confirm the reduction result by active flexion-extension of the joint and x-ray. Immediate mobilization protected by a splint preventing excessive extension is recommended for 3 weeks.
• In complete luxation, the MP joints of fingers II-V are slightly overextended and the finger cannot be flexed at any joint. This often requires operative treatment because the caput of the metacarpal bone is usually stuck between the flexor tendons and closed reduction will be unsuccessful.

Injury to the ulnar ligament of the thumb MP joint

• Injury to the ulnar collateral ligament (UCL) is typically due to forced radial abduction of the thumb, for example when falling down (also known as skier's thumb).
• Local tenderness in the UCL area
• Test the stability of the ligament with the MP joint straight and in slight (30°) flexion. If necessary, anaesthetize the thumb to obtain a reliable test result. Compare the range of motion with the uninjured hand.
  • A > 30° radial yield, a side difference of > 15° compared to the uninjured side, and absence of a clear end point are indicative of a complete rupture.
• An x-ray may show an asymmetric joint space or an avulsion fragment that has been torn away from the ligament insertion. If the fragment is > 2 mm dislocated or has turned over, operative treatment should be considered.
• A complete UCL rupture should be treated operatively. The diagnosis and surgical treatment should be done no later than about 2 weeks from injury.
• In a partial UCL rupture, the ligament will not yield when testing stability but everything else suggests ligament injury. This is usually treated with splinting for 6 weeks; during the last 2 weeks gentle range of motion exercises can be done.
• Thumb MP joint injuries can often be painful for up to 6 months.

Mallet finger Treatment of Mallet Finger Injuries

• Rupture of the extensor tendon of the distal phalanx (mallet finger, Image ) or avulsion fracture of the tendon (mallet fracture, Image ).
• Typically a closed trauma to an extended finger jolting the joint into flexion, for example if hit by a ball or when falling down. The trauma energy may be quite insignificant.
• The tip of the finger droops at the DIP (distal interphalangeal) joint and the patient cannot extend it; the passive range of motion is normal.
• X-raying is recommended to detect any avulsion fracture and to assess whether the DIP joint is in place.
• Treatment
  • A tendon injury in the absence of a fracture should be treated with the DIP joint splinted in extension for 6-8 weeks (Image ). The DIP joint must not be flexed even once during the treatment. The PIP joint should not be immobilized.
  • An avulsion fracture (mallet fracture) should be treated like just a tendon injury if the DIP joint stays in place. Surgical treatment should be considered if the avulsion fragment includes such an extensive part of the joint surface as to make the DIP joint subluxated.
  • After 6-8 weeks of 24-hour immobilization, the splint should be used for 2-4 weeks at night.
• An extension lag of 10-20° at the DIP joint usually remains even after successful treatment. The joint may be tender for several months.
• Splint treatment should be started even if the diagnosis is delayed, and the whole treatment can be repeated if the distal finger joint extension lag starts to increase again after the end of splinting.