Sports Medicine: Just the Facts

CHAPTER 62 • ANKLE INSTABILITY 371

CHRONIC ANKLE PAIN
AND INSTABILITY

PAIN VERSUS INSTABILITY

•For residual symptoms following an ankle sprain, ini-
tial work-up should center on whether the patient’s
chief complaint is pain or instability. This determina-
tion dictates further work-up on the different sides of
the diagnostic algorithm (see algorithm).

CHRONIC ANKLE PAIN

• In a retrospective study of 457 patients treated with
  immobilization or bracing, 72.6% reported residual
  symptoms at 6–18 months (Braun, 1999). A study of
  96 ankle sprains in west pointcadets found residual
  symptoms in 40% of ankles at 6 months post injury
  (Gerber et al, 1998).


• Common causes of chronic ankle pain are occult frac-
  tures, tendon tears, or ankle soft tissue impingement.
  •A bone scan (technetium-labeled nuclear medicine
  study) is an excellent screening test to rule-out occult
  fractures and to guide further treatment. If the bone
  scan reveals increased uptake in a discrete area, then a
  spot radiograph or CT scan is useful in further identi-
  fying the exact location of fracture.


• Occult or associated injuries to the tendons of the foot
  and ankle should also be considered. The physical exam-
  ination is crucial in testing for tendon integrity, strength,
  or tendon sheath swelling. MRI is the most useful exam-
  ination to identify and confirm tendon injuries.


• Injury to the lateral ankle ligaments may produce
  scarring of the ATFL and joint capsule leading to the
  formation of meniscoid tissue in the anterolateral
  ankle. This inflamed tissue is pinched between the
  talus, fibula, and tibia, leading to a condition called
  anterolateral impingement (Wolin et al, 1950).


• The distal fascicle of the anteroinferior tibiofibular
  ligament may abrade the anterolateral surface of the
  talus during ankle dorsiflexion during abnormal ante-
  rior translation of the talus (Bassett et al, 1990).


• An anomalous or accessory peroneal tendon may also
  cause chronic posterolateral ankle pain (Trono et al,
  1999). Its presence is confirmed by MRI.

CHRONIC ANKLE INSTABILITY

• If the primary problem is ankle instability, the patient
  will experience feelings of giving way of the ankle on
  uneven ground, inability to play cutting or jumping
  sports, loss of confidence in ankle support, reliance

on braces, and give a history of multiple ankle

sprains.

• The ankle should be evaluated with stress radi-
  ographs. If the stress radiographs are positive for
  mechanical lateral ligamentous laxity, then surgery is
  indicated to reconstruct the deficient ligaments.


• If stress radiographs disprove mechanical laxity of the
  lateral ankle ligaments, then the patient may have
  functional ankle instability rather than true mechani-
  cal ankle instability. Functional instability is the
  result of deficient neuromuscular control of the ankle,
  impaired proprioception, and peroneal weakness
  (Freeman, Dean, and Hanham, 1965; Gauffin, Tropp,
  and Odenrick, 1988). Treatment in this case should be
  directed toward restoring peroneal tendon strength,
  restoring ankle motion, and improving ankle proprio-
  ception with physical therapy.


• Other causes for ankle instability not demonstrated by
  stress radiographs include rotational instability of the
  talus, subtalar instability, distal syndesmotic (tibiofibu-
  lar) instability, and hindfoot varus malalignment
  (Hintermann, 1999).

SURGICAL TREATMENT

INDICATIONS FOR SURGERY

• Multiple episodes of mechanical instability, i.e., diffi-
  culty walking on uneven ground, inability to play cut-
  ting sports, and lack of confidence in ankle stability


• Demonstration of mechanical instability on stress
  radiographs
  •Failure of a full course of physical therapy emphasiz-
  ing peroneal strengthening and proprioceptive training
  •Failure of a course of bracing

SURGICAL PROCEDURES

• Most procedures are designed to tighten or recon-
  struct the ATFL and CFL.


• Ankle reconstructive procedures are described either
  as anatomic or nonanatomic procedures. Anatomic
  reconstructions attempt to tighten lateral ligaments or
  transfer tendons into the exact anatomic locations of
  the ATFL and CFL. Nonanatomic reconstructions use
  tendon transfers to act as a tenodesis on the lateral
  side of the ankle, although they do not attempt to
  place the transferred tendons to the exact anatomic
  origins of the ATFL or CFL. Most surgeons agree that
  anatomic reconstructions are preferable.


• The Brostrom procedure is an anatomic reconstruc-
  tion in which the ATFL and CFL are divided and