Sports Medicine: Just the Facts

CHAPTER 53 • SOFT TISSUE INJURIES OF THE HAND IN ATHLETES 309

EXTENSOR TENDON SUBLUXATION
AND DISLOCATION

• Extensor tendons usually subluxate or dislocate to the
  ulnar side of the metacarpophalangeal joint, usually
  resulting from a direct blow to the digit with forced
  flexion and ulnar deviation. Radial subluxation is rare.
  The middle finger is most commonly affected.
  Patients present with tenderness over the MCP joint,
  pain with resisted extension, inability to fully extend
  at the joint and often palpable tendon subluxation or
  dislocation (Rettig, Coyle, and Hunt, 2002; Rettig,
  1992; Aronowitz and Leddy, 1998).


• Acute injuries (presenting within 4–6 weeks) may
  respond to extension splinting of the MCP joint.
  Chronic or recalcitrant cases often require surgical
  reconstruction with release of contractures and repair
  of the extensor hood and sagittal bands (Leddy, 1998;
  Rettig, 1992).

BOXER’S KNUCKLES

• This injury, also known as soft knuckles, is caused by
  repetitive trauma to the dorsal MCP joints, most com-
  monly involving the index and long digits. The injury
  manifests as pain and swelling over involved joints,
  usually improving with rest but recurring with
  resumed training (Rettig, 1992).


• The anatomic basis of injury usually involves tears of
  the extensor hood, extensor tendon, or dorsal joint
  capsule. Rest or splinting is of little benefit; explo-
  ration with surgical repair of injured structures is
  often required (Leddy, 1998; Rettig, 1992; Hame and
  Melone, 2000).

JERSEY FINGER

• Jersey finger involves an avulsion of the flexor digito-
  rum profundus (FDP) tendon from its insertion on the
  distal phalanx, commonly occurring in football and
  rugby players. Greater than 75% of cases involve the
  ring finger (Rettig, Coyle, and Hunt, 2002; Leddy,
  1998; Leddy, 1985).


• Injury is caused by forced DIP extension during max-
  imal FDP contraction, as in grabbing someone’s jersey
  while attempting to tackle. Clinical findings include
  the inability to actively flex the DIP joint, with normal
  passive range of motion. Radiographs are usually
  negative unless a bony fragment is avulsed with the
  tendon (Rettig, 1992; Aronowitz and Leddy, 1998).


• Injuries are graded and treated according to sever-
  ity that depends on the degree of tendon retraction.

In type I injuries, the tendon retracts into the palm.

In type II injuries, the tendon retracts to the level of

the PIP joint. In type III injuries, the tendon retracts

only to the A4 pulley. These are nearly always asso-

ciated with a large avulsed bony fragment (Leddy,

1998; Rettig, 1992; Aronowitz and Leddy, 1998;

Leddy, 1985).

• All require surgical intervention, but the greater the
  degree of retraction, the more quickly surgical inter-
  vention is required. Type I injuries should be
  addressed within 7–10 days, whereas type III injuries
  are often successfully treated up to 2–3 months later
  (Rettig, Coyle, and Hunt, 2002; Leddy, 1998).

TRIGGER DIGITS

•Trigger digits involve inflammation of the flexor ten-

dons as they pass through the digital flexor pulleys,

especially the first annular (A1) pulley. Most occur

secondary to chronic degenerative changes of the

involved structures, but direct pressure from racquets,

baseball bats, or golf clubs can also cause acute

inflammation of the pulley and tendons (Rettig,

2001).

• The injury manifests as pain in the flexor area over the
  A1 pulley (metacarpal head) and may also produce
  catching or locking as swollen tendons attempt to pass
  through pulley.
  •A large percentage of trigger digits will respond to
  steroid injection into the tendon sheath and pulley.
  Surgical release of the A1 pulley may be either a first-
  line treatment or reserved for cases unresponsive to
  injection (Rettig, 2001).

NERVE COMPRESSION INJURIES

HANDLEBAR PALSY

• This injury, also known as cyclist’s palsy,is caused by
  compression of the ulnar nerve at the hand and wrist
  as the result of direct pressure from the grip on the
  handlebars and wrist hyperextension. Patients present
  with paresthesias and dysesthesias in the ulnar nerve
  distribution (ring and small digits), a positive Tinel’s
  sign over Guyon’s canal, and possible weakness of the
  intrinsic hand musculature (Rettig, 2001).


• Rest, stretching exercises, and anti-inflammatory
  medications usually help relieve the symptoms.
  Symptoms may take from several days to months to
  resolve. Surgical treatment is occasionally necessary.
  Applying less pressure or weight to the handlebars
  and avoiding hyperextension by altering handlebar