Sports Medicine: Just the Facts

CHAPTER 62 • ANKLE INSTABILITY 367

• Early mobilization of joints following ligamentous
  injury actually stimulates collagen bundle orientation
  and promotes healing, although full ligamentous
  strength is not reestablished for several months
  (Noyes et al, 1974; Tipton et al, 1970; Vailas et al,
  1981).


• Early treatment focuses on limiting soft tissue effu-
  sion, which speeds the healing process by lessening
  the amount of extracellular fluid and hematoma to be
  reabsorbed (Hettinga, 1985; Safran et al, 1999a;
  Thorndike, 1962).

PHYSICAL EXAMINATION

• Lateral ankle swelling and ecchymosis are present
  and are proportional to the degree of ligament
  damage.


• Careful one finger palpation is essential to define
  areas of tenderness and avoid misdiagnosis of associ-
  ated fractures or tendon ruptures.


• Common fractures that mimic ankle sprains are frac-
  tures of the lateral malleolus and medial malleolus,
  fifth metatarsal base, anterior process of the calca-
  neus, lateral process of the talus, posterior talar
  process, talar dome, and navicular.


• Commonly missed tendon injuries are Achilles rup-
  tures, peroneal tendon tears, peroneal tendon sublux-
  ation/dislocation, posterior tibial tendon injuries,
  anterior tibial tendon tears, and flexor hallucis longus
  tendon ruptures.
  •A careful neurologic examination is essential to rule
  out loss of sensation or motor weakness, as peroneal
  nerve and tibial nerve injuries are sometimes seen
  with severe lateral ankle sprains (Nitz, Dobner, and
  Kersey, 1994).

DIAGNOSTIC TESTS

ANTERIOR DRAWER TEST

•Tests the integrity of the ATFL.

• Performed by stabilizing the anterior tibia just above
  the ankle with one hand while grasping the posterior
  heel with the other hand and applying an anteriorly
  directed force, therefore attempting to translate the
  talus anteriorly.


• The test should be performed on a relaxed leg with the
  knee bent and the ankle held in slight plantar flexion.


• Normal anterior talar translation is less than 5 mm.
  The contralateral asymptomatic ankle should also be
  tested as a baseline.

INVERSION STRESS TEST OR TALAR TILT TEST

•Tests the integrity of the ATFL and CFL.

• Performed by grasping the heel and inverting the
  ankle. A clunk may be heard or palpated in unstable
  ankles, as the medial talar dome impacts the distal
  tibial medial articular surface, indicating injury to one
  or both ligaments.


• This test should be performed with the ankle in both
  dorsiflexion (to test the CFL) and plantar flexion (to
  test the ATFL).

SUCTION SIGN

•Tests the integrity of the ATFL.

• During performance of the anterior drawer test, an
  unstable ankle will produce a dimple in the anterolat-
  eral ankle as the talus reaches its full anterior excur-
  sion. The dimple is formed by negative pressure
  within the ankle joint (Hockenbury and Sammarco,
  2001).

SQUEEZE TEST

•Tests the integrity of the syndesmotic ligaments.

• The squeeze test is performed by placing the fingers
  over the proximal half of the fibula and thumb around
  the tibia and squeezing the two bones together. Pain in
  the distal ankle may indicate a syndesmotic injury
  (Hopkinson et al, 1990; Ryan et al, 1989).

EXTERNAL ROTATION STRESS TEST

•Tests the integrity of the syndesmotic ligaments.

• The external rotation stress test is performed on the
  seated patient by externally rotating the foot while sta-
  bilizing the tibia with the other hand. Medial ankle
  pain or lateral talar motion indicates a syndesmotic
  injury may be present.


• Confirmatory anteroposterior and lateral external rota-
  tion stress radiographs will document widening of the
  syndesmosis and lateral talar subluxation (Edwards, Jr,
  and DeLee, 1984; Xenos et al, 1995).

IMAGING

OTTAWA ANKLE RULES

•Every sprained ankle does not require screening radi-

ographs.