Ankle Sprains

Michael W. Bowman M.D. FACS

The ankle joint is composed of 3 bones, the tibia(the bone or shin bone), the smaller fibula, and the curved talus, which is attached to the foot and  Rotates up and down with the foot the ankle joint behaves like a mortise joint or sophisticated hinged joint. . there are actually 3 joints in the human ankle joint-the tibiotalar joint,( or main ankle joint), the tibiofibular joint and the talofibular joint.  The ankle joint has up to 15 degrees of upward motion or dorsiflexion and up to 30 degrees of downward motion or plantar flexion.  There are 3 lateral ankle ligaments- the anterior talofibular ligament, the calcaneofibular ligament and the posterior talofibular ligament.  On the medial side(great toe side) the deltoid ligament is composed of the superficial and deep component and connects the tibia and talus.

Ankle sprains are one of the most common orthopaedic injuries, with an estimated 27,000 recurring in the United States each day.  Ankle sprains are much like Rodney Dangerfield because they “get no respect". most ankle sprains are treated conservatively, with limited or no treatment.  Fortunately most do well with this benign neglect although studies and my personal experience note that up to 15% of patients in depth with serious continuing symptoms or complications after an ankle sprain.  In  , I conducted a multi-Center ankle sprain study for the American orthopedic foot and ankle Society to steady ankle sprains and conservative treatment.  With appropriate early treatment of ankle sprains, we were able to reduce the incidence of severe complications to 4%.

The most common type of ankle sprains he is a lateral ankle sprain, involving injury to the lateral ankle ligaments.  75% involved the ATF ligament, with 40% involving the CF ligament and 9% involving the ATF.  The usual mechanism for producing a lateral ankle sprain is an entry to the foot down in plantar flexion and twisting in or inversion. the patient may notice a “ pop" and immediate discomfort.  There was usually be swelling around the fibula on the lateral side of the ankle as well as bruising or ecchymosis.  In some cases the lateral ankle ligaments may detach with a small piece of bone, producing an avulsion fracture of the fibula.

a medial ankle sprain, involving the deltoid ligament, occurs in approximately 4 to 7% of ankle sprains.  A common mechanism is eburnated or turning the ankle out with the foot dorsiflexed.  The patient will usually noticed swelling medially with bruising.  Occasionally a lateral ankle injury will result in tearing of the inner osseous ligament between the tibia and fibula, causing a so-called “high sprain". this is a more severe version of the common lateral ankle sprain, resulting in a higher incidence of instability and chronic problems.  It must be treated more aggressively and can take between 6 to 12 weeks to heal.

Initial evaluation of ankle sprains involves obtaining the history of injury, and careful physical examination.  We examined for range of motion, tenderness over the bones or ligaments and signs of instability. the anterior drawer test involves pulling the talus forward in the ankle joint and checked the stability of the ATF ligament.  The talar tilt test involves pulling the talus into varus toward the big toe and checks the CF ligament.  The eversion test checks for stability of the interosseous ligament and involves twisting the talus laterally towards the fibula and spreading the tibia and fibula.  X-rays are usually taken to rule out any fractures.

Initial treatment of acute ankle sprains involves protection with a protective boot or Aircast stirrup to avoid future injury.  Weight-bearing is allowed as tolerated.  Therapy was started immediately to avoid swelling and to regain range of motion.  Once the swelling is diminished and range of motion is regained, strengthening exercises are initiated to strengthen the muscles around the ankle joint-the secondary stabilizers of the ankle.  Balance and proprioception exercises are started.  Once the swelling is diminished, range of motion is good and stability is regained, continued strengthening in sport specific exercises are initiated. ankle sprains involving small evulsion fractures that are nondisplaced may be treated with a protective boot nonweightbearing for two to 3 weeks, followed by the above treatment plan.  For Ankle sprains involving significant fractures, the fracture may need to be repaired with internal fixation. this surgery is performed as an outpatient with general or spinal anesthesia.  A small incision is made over the fracture, the fracture and ligaments are repaired directly.  There is a protective boot and nonweightbearing for 4 to 6 weeks, followed by the above ankle rehabilitation program.

A chronic ankle sprains is an ankle sprain that has continuing symptoms such as persistent instability with giving way episodes, chronic swelling or pain or stiffness. the most common complication after ankle sprain stiffness, secondary to scarring and healing of the injured ankle ligaments.  Scar tissue is not as elastic as normal ligamentous tissue.  Treatment consists of therapy to regain motion, followed by strengthening.  In severe cases, arthroscopy and debridement or trimming of the scar tissue in the ankle capsule they be required.  This is an outpatient procedure with general or spinal anesthesia.  There will be a protective boot and nonweightbearing afterwards with immediate therapy to begin range of motion.  Patient's with mild instability of the ankle after an ankle sprain may notice chronic swelling and discomfort in the anterior(front) and lateral portion of the ankle secondary to irritation from the talus sliding slightly out of place with activities. cases of severe ankle instability will include recurrent giving way episodes as well a swelling and discomfort.  Initial treatment baby appropriate ankle rehabilitation and strengthening as described above.  Orthotics with a lateral heel wedge may also be used.  If conservative treatment does not work, arthroscopy and lateral ligament stabilization they be required.  We pioneered this innovative minimally invasive technique approximately 10 years ago. this procedure is performed as an outpatient under general or spinal anesthesia.  Two small incisions or portals are made in the front of the ankle.  An arthroscope is inserted to visualize the joint.  A small shaver is used to debride or clean up the joint.  A thermal probe was then inserted to heat and shrink collateral ligaments.  After surgery a protective boot and dressing are applied.  There is no weight-bearing for 6 weeks while the ligament is healing, similar to the older open techniques.  At 6 weeks the appropriate ankle rehabilitation program and progressive weight-bearing is begun. risks include anesthesia needed the risks, wound healing problems infection.

Other causes for the “ ankle sprain that does not get better" are associated undiagnosed injuries that occur at the time of injury.  These include an osteochondral lesion of the talus(OLT)], which is a small fracture of the cartilage and bone of the talus produced when it twists inside the ankle during the sprain injury.  This injury is frequently not diagnosed until months after the injury and the initial x-rays may be negative.  Sometimes an MRI is required to detect the problem.  Treatment involves arthroscopy and debridement or removal of the small fragment.  Occasionally large OT fragments may be surgically fixed at the time of arthroscopy.  This is also an outpatient procedure with general or spinal anesthesia.  A protective boot and nonweightbearing is utilized for 6 weeks after the surgery.  Risks with surgery or possible sequelae of this injury include anesthesia needed risks, wound healing problems, infection or ankle arthritis.  Another injury that is frequently missed is a small avulsion fracture from the front or anterior lateral part of the calcaneus.Left untreated, the fracture will frequently not heal, resulting in a painful nonunion.  Treatment consists of removing the small fracture fragment.  This procedure is performed as an outpatient with general or spinal anesthesia.  There is limited weight-bearing for two to 4 weeks after surgery, followed by therapy.  Surgical risks include anesthesia needed the risks, wound healing problems or infection.