Relevant Anatomy

The ankle, or talocrural joint, is a junction of the tibia, fibula, and talus (Fig. 5-1). The anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), and posterior talofibular ligament (PTFL) provide static support to the joint laterally (Fig. 5-2A), whereas the deltoid ligament complex (DLC), made up of the anterior and posterior tibiotalar ligaments, the tibiocalcaneal ligament, and the tibionavicular ligament, provides medial support (Fig. 5-2B). The inferior anterior and posterior tibiofibular ligaments and the interosseous membrane provide additional support for the talocrural joint (Fig. 5-2C and D).

Figure 5-1 The ankle, which is a junction of the talus, the tibia, and the fibula.

Figure 5-2 Ankle anatomy. A, Static support for the lateral ankle includes the anterior talofibular ligament (ATFL), the calcaneofibular ligament (CFL), and the posterior talofibular ligament (PTFL). B, Static support for the medial ankle is provided by the deltoid ligament complex (DLC). C and D, An anterior (C, left) and posterior (D, right) view of the ankle showing the ATFL, CFL, PTFL, DLC and the anterior inferior tibiofibular ligament and posterior tibiofibular ligament, which provide additional support to the joint.

The ATFL is the most commonly injured ligament, followed by the CFL. The CFL is usually injured in combination with the ATFL. Sprains to both the ATFL and CFL are a result of a combined inversion and plantarflexion mechanism (Fig. 5-3A). A less likely mechanism of eversion may cause injury to the DLC (Fig. 5-3B). Injury to the anterior and posterior tibiofibular ligaments (syndesmosis) and the interosseous membrane are discussed later in this chapter.

Figure 5-3 Mechanisms of injury. A, Inversion with plantarflexion is the most common mechanism of injury for ankle sprains and will typically result in injury to the anterior talofibular ligament (ATFL) and possibly the calcaneofibular ligament (CFL). B, Although not as common as an inversion sprain, eversion is the mechanism of injury for sprains of the deltoid ligament complex (DLC). C, The peroneal tendons are lateral dynamic stabilizers of the ankle.

The muscles that attach to and act upon the foot provide dynamic control of the ankle. The peroneal muscle group, composed of the peroneus brevis, longus, and tertius muscles, is of significant importance because they are responsible for everting the ankle and, therefore, resisting inversion (Fig. 5-3C). Because there are no muscles that attach directly to the talus, motion of the talus is dictated by foot and ankle position. The most stable position of the ankle is in dorsiflexion. As the foot moves into dorsiflexion, the talus glides posteriorly and the widest portion of the talus becomes wedged into the ankle mortise. As the ankle moves into plantarflexion, the talus glides anteriorly and the ankle becomes less stable, which is why most ankle sprains involve some degree of plantarflexion as the mechanism.

Classification of Ankle Sprains

Regardless of whether the lateral or medial ligaments are injured, the severity of an ankle sprain is typically placed into one of three grades based on the amount of ligamentous damage. The degree of tissue damage, the amount of joint laxity, and the extent of dysfunction increase with each increase in grade.

Diagnosis

It is only through a thorough examination that the severity of an ankle sprain can be established (Table 5-1). Detailed information on conducting a thorough examination of the ankle is beyond the scope of this text; however, common signs and symptoms associated with each grade of lateral ankle sprain are listed in Table 5-2. The examiner must also be aware of additional injuries that can occur with ankle sprains. Such injuries include, but are not limited to, avulsion fractures, fractures, muscle and tendon strains, articular cartilage damage of the ankle mortise, and tarsal subluxations and dislocations. Although some of these injuries (such as muscle strains) can be adequately treated with the following standard treatment protocol, others (such as articular cartilage damage) may require revisions of the standard treatment protocol for ankle sprains.

Table 5-1 Examination of the Ankle After an Inversion Injury

Table 5-2 Clinical Signs and Symptoms Associated with Ankle Sprains

ATFL, anterior talofibular ligament; CFL, calcaneofibular ligament; FWB, full weightbearing; PTFL, posterior talofibular ligament.

The emphasis for the following standard treatment protocol is placed on treating ankle sprains in the absence of other significant injuries. It should be noted that the patient should be re-evaluated throughout the rehabilitation program for any limitations that need to be considered. For example, although it is common to include stretching of the heel cord in a rehabilitation protocol for ankle sprains, a specific patient may not have tightness of the heel cord and therefore may not need to perform the stretches. It is also important to look for signs of aggravation or reinjury (e.g., increased pain, increased tenderness, increased swelling, decreased range of motion, decreased strength). Occasionally, even the best-planned rehabilitation protocols can cause aggravation to an injury. It is important that the therapy provider know when it is time to slow down or change the protocol. Also, some patients may buy into the “no pain, no gain” philosophy and not report an increasingly painful and stiff ankle, believing it needs to be pushed harder to get better when the opposite may be true.

The Injury and Healing Process

The body’s healing process occurs in a natural sequence of events and can be divided into three stages: the inflammatory or acute stage; the subacute, repair, or proliferation stage; and the remodeling or maturation stage. It is important to have an understanding of what takes place during each of these stages in order to support the body’s natural healing process and limit the potential for additional injury. Although a full description of all of the events that occur during the stages of tissue healing is beyond the scope of this text, a summary of the clinically relevant events follows.

In the acute stage, the cardinal signs and symptoms of inflammation (pain, edema, erythema, warmth, decreased function) are evident. This stage begins immediately after the onset of injury and typically lasts 3 to 5 days.

The subacute stage, which begins at about 3 days after injury and can last up to 6 weeks, is marked by a decrease in the signs and symptoms of inflammation and the beginning of tissue repair. It is during this stage that weak collagen fibers begin to develop a scar at the injured site. Approximately 7 days after injury, there is a significant amount of collagen in the area. As the subacute stage progresses, it is important to provide some stress to the newly forming scar tissue to minimize adherence to surrounding tissues and to encourage proper scar tissue alignment and development; however, in the early stages the collagen fibers are weak and unorganized so it is more important to avoid too much stress, which can be detrimental to the healing tissues.

Activities associated with the maturation stage begin approximately 1 week after injury in grade I sprains and approximately 3 weeks after injury in grade III sprains. During the maturation stage, the collagen tissues become stronger and more organized. Although nowhere near normal, the scar’s tensile strength usually has increased considerably by the fifth or sixth week. It is important to stress the scar tissue adequately to decrease the potential of developing a dysfunctional scar. Appropriate levels of tissue stress will also continue to encourage proper alignment and development as the scar tissue matures. The maturation phase can last longer than a year, although patients typically return to their activity level much sooner than that.

Treatment and Rehabilitation Protocol for Acute Ankle Sprain

It is important to remember that the duration of each stage of tissue repair depends, in part, on the extent of injury. Because there is less tissue damage in a grade I sprain, there is a shorter duration of healing with a quicker transition from one phase of tissue healing to the next when compared to a grade II sprain. This is important to consider when establishing a treatment and rehabilitation protocol because patients with grade I sprains can be progressed quicker than patients with grade II sprains. The same can be said when comparing grade II and grade III sprains. Although many factors affect the length of time before a patient can return to normal physical activities, patients with grade I sprains can often return to their normal physical activity levels within 1 to 2 weeks, whereas patients with grade II sprains can expect to return in 4 to 8 weeks. There is a greater range of expected return estimates in patients with grade III injuries, which can take as long as 12 to 16 weeks to recover.

Without ignoring where the injury is in the healing process, the clinician should progressively manage the patient’s signs and symptoms, functional limitations, and impairments instead of solely focusing on the number of days since the injury. Table 5-3 lists the common signs and symptoms associated with each stage of tissue healing. Changes in the signs and symptoms, in addition to the number of days postinjury, can help the clinician determine when to progress the patient’s treatment and rehabilitation program.

Table 5-3 Clinical Signs and Symptoms Associated with the Stages of Tissue Healing

⇑, increased; TTP, tenderness to palpation; ROM, range of motion; ⇓, decreased; s/s, signs and symptoms.

* Presence and amount depend on severity of sprain.

The steps in treating and rehabilitating ankle sprains typically follow this progression:

While the rehabilitation program is progressing through these steps that focus on the injured ankle, it is important to maintain overall strength and conditioning for the rest of the body. Rehabilitation Protocol 5-1 provides an outline of the ankle sprain rehabilitation protocol described here.