1. Metacarpal and phalangeal fractures are the most common fractures in the upper extremity.

2. Diagnosis requires a thorough history, physical examination, and radiographic images.

• Specifically, look for open lacerations, digital shortening, malrotation (see Figures 16.1 and 16.2), scissoring, gross deformity, and angulation (see Figure 16.3), which affects hand motion/function.

3. Most fractures can be treated nonoperatively; however, the unique anatomy of the hand and associated muscular attachments can result in displacement, rotation, misalignment, and significant functional deficits.

4. General indications for fixation of these fractures are shown in Table 16.1

5. Numerous fixation techniques are available, although many fractures can be adequately fixed with percutaneous pinning (see Table 16.2).

1. Mallet finger (see Figure 16.4): Disruption, either tendinous or bony, of the terminal extensor tendon at or distal to the distal interphalangeal joint (DIPJ)

• Etiology: Forced flexion of the DIPJ due to an impaction force to tip of extended finger

• Characterized by a painful, swollen DIPJ, with the fingertip resting in flexion without active DIP extension

• Treatment

▪ Extension splinting of the DIPJ for 6 to 8 weeks; keep proximal interphalangeal (PIP) joint free

▪ Operative repair is indicated with volar subluxation, >50% articular surface involvement, and/or >2 mm articular gap. Can be performed with

○ Pin fixation

○ Dorsal blocking pin

○ Open reduction internal fixation (ORIF)

▪ Terminal tendon reconstruction in chronic injuries (>12 weeks)

▪ DIP arthrodesis is reserved for treatment of chronically painful, arthritic DIP joints.

• Complications

▪ Extensor lag

▪ Swan-neck deformity

2. Jersey finger: Avulsion of the flexor digitorum profundus (FDP) tendon from its insertion at the base of the distal phalanx

• Etiology: Forced DIPJ extension of an actively flexed DIPJ (i.e., athlete grasping a moving object such as a jersey, etc.)

▪ The ring finger is involved in most cases because it is the most prominent fingertip exposed to the force of gripping.

• Characterized by pain, tenderness over the volar distal finger, with the finger in extension relative to others, and no active DIPJ flexion.

• Leddy-Packer classification (see Table 16.3)

▪ Based on the level of tendon retraction and presence of fracture

▪ One of the only classification systems where the lowest type (type I) is associated with the worst pathology

▪ Type II is the most common.

• Treatment (see Figure 16.5)

▪ Types I, II: Direct tendon repair or tendon reinsertion with a dorsal button

○ Indications: Acute injuries (<4 weeks)

○ Complications: Advancement of the FDP tendon >1 cm can lead to DIP contracture or quadrigia (functional shortening of FDP tendon, leading to a flexion lag of adjacent fingers).

▪ Types III, IV: ORIF of the fracture fragment with a K wire, screw, or pull-out wire

▪ Two-stage flexor tendon grafting indicated in patients with chronic injuries and full passive range of motion (PROM).

▪ DIPJ arthrodesis: Salvage procedure in patients with chronic injuries and limited range of motion (ROM)