Research Review By Dr. Demetry Assimakopoulos©

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Date Posted:

February 2013

Review Title:

Ankle Sprains: Diagnosis, Treatment & Prevention

Studies Reviewed:

  1. Kerkhoffs GM & Tol JL. A twist on the athlete’s ankle twist: Some ankles are more equal than others. British Journal of Sports Medicine 2012; 46(12): 835-836.
  2. Kerkhoffs GM, Bekerom M, Elders LM et al. Diagnosis, treatment and prevention of ankle sprains: An evidence-based clinical guideline. British Journal of Sports Medicine 2012; 46(12): 856-860.
  3. Tully MA, Bleakley CM, O’Connor SR et al. Functional management of ankle sprains: What volume and intensity of walking is undertaken the first week. British Journal of Sports Medicine 2012; 46(12); 877-882.

Background Information:

This review is a synthesis of 3 articles from the September 2012 issue of the British Journal of Sports Medicine. In these papers, the authors discuss various ways we can diagnose and treat acute lateral ankle injuries in athletes.

Currently, more and more athletes are being treated with functional rehabilitation for ankle sprains. This type of treatment has evolved over time from prior approaches such as complete cast immobilization and surgical stabilization…we’ve come so far!

The present evidence shows that contemporary, functional exercise-based treatments are more desirable, due to their cost effectiveness and resultant decrease in surgical complications. This approach includes progressive weight bearing exercise and walking, which have shown more positive results than passive approaches when evaluated in clinical trials.

This review discusses the work of a research/clinician group from the Netherlands, whose work culminated in the creation of a clinical guideline for acute lateral ankle ligamentous injuries. Their goal was to outline a uniform method of diagnosis and treatment, and to establish methods of preventing recurrence of these injuries. Additionally, our discussion will conclude with a description of how and why optimal loading is important for the management of ligamentous ankle injury.

Summary:

What are the predisposing risk factors for ankle sprain?

Intrinsic Risk Factors:
  • Decreased strength
  • Decreased proprioception (level 2 evidence)
  • Limited range of motion, especially dorsiflexion (level 2 evidence)
  • Poor balance in patients older than 15 years of age generally leads to a greater number of injuries
Extrinsic Risk Factors:
  • The highest incidence of lateral ankle injury was found in athletes who compete in aero-ball, wall climbing, indoor volleyball, rock climbing, basketball and various field sports (level 2 evidence)
  • Playing soccer on artificial grass increases the chance of lateral ankle injury. Lateral ankle injuries are also more frequent in defenders due to the greater physical contact they have with opponents (level 2 evidence)
  • In volleyball, how one lands after a jump task appears to the most important risk factor (level 2 evidence)
What are the best prognostic factors?
  • There is an extreme lack of evidence on this topic
  • Natural history for lateral ankle sprains is good – pain decreases rapidly in the first 2 weeks (level 1 evidence)
  • Five percent of patients have complaints of instability or recurrent distortion after 1 year (level 1 evidence)
  • High level competition is a negative prognostic factor (level 3 evidence)
  • Increased ligament laxity post-sprain is also a negative factor (level 3 evidence).
  • The ability to walk 48 hours post-injury is a good prognostic factor.
What are Best-Practice Diagnostics?
  • The presence of a hematoma with local pain to palpation and/or a positive anterior drawer indicates at least a partial lateral ankle ligament tear exists.
  • Delaying to 4-5 days post-injury has a sensitivity of 96% and a specificity of 84%, compared to examinations taking place 48 hours post-injury (level 2 evidence). For a solid diagnosis, patients must be re-examined 4-5 days post-trauma.
  • History and mechanism of injury are, of course, key indicators.
What are the best Treatments?

Ice and Compression:
  • The effect of cryotherapy on lateral ankle injuries is unclear
  • Ice and exercise therapy has positive effects on swelling, compared to heat application
  • No conclusive evidence exists stating that ice on its own can increase function, reduce swelling and reduce pain at rest (level 2 evidence)
  • Compression shows conflicting results
  • However, the use of rest, ice, compression and elevation (RICE) remains an important aspect of acute treatment.
Immobilization:
  • Short periods of plaster immobilization or other rigid supports can result in a rapid decrease in pain and swelling in the acute phase
  • Functional treatment (see below) over the course of 4-6 weeks is the preferred treatment modality
Optimal Functional Treatment after Acute Injury:
  • Elastic bandages have fewer complications than adhesive tape, but are associated with a delayed return to work and sport.
  • Instability is reported less frequently in individuals who use a semi-rigid or lace-up brace – therefore these brace types are recommended
Exercise Therapy:
  • Prevents recurrences in patients with lateral ankle injury in the long term (Level 2 evidence)
  • Has no significant impact on balance in the medium term (6-9 months)
  • Exercise therapy should be used in the treatment of this injury, both in clinical settings and at home
Manual Mobilization:
  • There seem to be limited positive short term effects exist for manual mobilization (Level 2 evidence)
  • This therapy can improve dorsiflexion, ROM and proprioception, but only for a short period of time based on current evidence.
  • Effects seem to disappear 2 weeks post-injury
  • Manual mobilization has very limited added value and is not recommended by the research group.
Other Therapies:
  • There is no added effect with the use of ultrasound, laser therapy or electrotherapy (Level 1 evidence)
  • Short wave therapy is ineffective (Level 2 evidence)
Surgical Intervention:
  • Can result in longer recovery times, and greater incidence of ankle stiffness, impaired ankle mobility and complication (Level 2 evidence)
  • Insufficient high-quality RCTs exist to allow a final judgment on the effectiveness of surgery. For now, functional exercise is the treatment method of choice. Surgery should only be considered in professional sporting athletes on an individual basis.
What are the best ways to Prevent Re-injury?

Exercise Therapy:
  • Exercise therapy shows no significant benefit on balance after 6-9 months of follow-up in patients with lateral ankle injury. Training coordination and balance have no effect on primary prevention of inversion sprain (Level 2 evidence). However, this type of training can prevent recurrence of ankle injury in athletes up to 12 months post-injury.
  • It is recommended that balance and coordination training be started in athletes within 12 months of injury and should be integrated into training programs in an attempt to prevent injury.
Tape or Braces:
  • Can reduce the risk of recurrent inversion injury in individuals who are active in sporting activities (Level 2 evidence).
  • It is unclear if a brace is more effective than tape, but due to cost and practicality, a brace is often recommended over tape.
  • Using tape or a brace to prevent a relapse is advisable. However, the patient should be slowly weaned off its use over the course of time.
Return to Work:
  • Individuals who use semi-rigid ankle braces often resume work faster than those who use an elastic bandage (Level 2 evidence).
  • A return to work schedule which takes into account the tasks of the individual can contribute to returning to work.
Return to Sport:
  • A longer-term disturbance in proprioception subsequent to a lateral ankle injury (leading to functional instability) appears to stem from the CNS spinal reflexes (Level 2 evidence).
  • The delay in response of the fibularis muscle activity may be due to a traction injury to the fibular nerve, occurring during the inversion sprain. Additionally, strength decrease in the extensor muscles that are used for eversion may contribute to this phenomenon. Training these muscles may be beneficial to prevent recurrence (Level 2 evidence).
  • Rehabilitation resulting in the improvement of proprioception, strength, coordination and overall function of the extremity is key.
Early Walking for Lateral Ankle Sprains (Tully et al. ):

With regards to the amount of walking one performs in the first week post-ankle sprain, individuals who perform the standard rest, ice, compression and elevation (RICE) protocol spend less time walking and walked fewer steps/day compared to the group who performed non-weight bearing exercises and the non-injured control group. The group who performed the standard passive treatments also took fewer steps during moderate and long bouts of walking at a lower cadence. Both injured groups performed less moderate and high intensity physical activity/day. The exercise group differed from the non-injured control group only by the quantity and the number of steps taken during extra-long bouts of walking. It is important to note, however, that no between-group differences with regards to subjective function and re-injury rate were found 4-months post-injury.

Clinical Application & Conclusions:

One popular approach to functional rehabilitation of lateral ankle ligamentous injury is to encourage walking within the boundaries of pain. This study revealed that this approach to treatment results in more walking during the first week post-ankle sprain. They also established the number of steps taken by individuals who suffer a lateral ankle sprain as a baseline for future intervention studies.

Most importantly, the incorporation of additional exercises into a functional treatment may allow the injured person to perform a faster walking cadence and a greater volume of walking. However, it is unknown if this is a favorable loading strategy.

Optimal Loading for Ligament Healing:

Why is applying a tolerable load important for healing? The answer to this comes from the concept of mechano-transduction; a physiological process in which cells “sense” and appropriately respond to mechanical load. Ligaments are structures that are micro-sensitive. They adapt to the changes in mechanical load associated with walking and other forms of exercise. It has been proven in vitro, that loading injured tendons and ligaments can result in the up-regulation of mRNA expression for proteins that are associated with healing, increases in fibroblast proliferation, matrix remodeling, fibrillogenesis, better tensile strength and improved scar morphology. Because of this, it is advisable for practitioners to take advantage of the mechano-sensitivity of ligaments to improve healing post-ankle sprain.

Many popular and vocal therapists throughout the world have begun to advertise the idiom of treating histology, not pain. The new frontier of mechano-transduction more aptly describes this concept: a loading strategy which exploits the histological and mechanical properties of the injured tissue. Walking is an easy and practical way of introducing load in the early stages after ankle ligament injury. However, an optimal “dose” still remains to be determined.

Individuals who sustain lateral ankle injury do reduce their walking speed, intensity and frequency in comparison to a non-injured group. However, with an optimal loading strategy through therapeutic exercise (in this case, range of motion exercises), walking frequency and cadence may be restored more quickly. However, the duration of any one bout of walking may still be reduced for a longer period of time. The authors conclude by stating that having these baseline walking values (speed, duration, intensity, frequency, and number of steps) is an important step toward the creation of an evidence-based walking prescription post-acute ankle sprain.

Study Methods:

For article number 2, relevant articles were found through searching the Cochrane Library, Medline and Embase, and the bibliographies of the articles themselves. Levels of evidence and conclusions were assigned to specific categories, on the basis of ‘evidence-based guideline development.’ Additionally, each contributor took other variables into account, such as potential harm of the intervention to the patient, the perspective of the patient, costs and organizational/logistical aspects, to create an overall score.

The articles included in study number 2 were classified based on their methodological quality:
  • Level A1: systematic review of at least 2 independently conducted studies of A2 level.
  • Level A2: RCTs that are double-blind, good quality of sufficient size.
  • Level B: Comparative research, without all of the features of A2.
  • Level C: Non-comparative research.
  • Level D: opinion of experts.
Conclusions and recommendations are based on:
  • Level 1: Research at the A1 Level or at least 2 examinations at the A2 Level, performed independently of one another, with consistent results.
  • Level 2: One study graded at Level A2 or at least 2 examinations of Level B, performed independently of one another.
  • Level 3: One examination at Levels B or C.
  • Level 4: Expert opinion.
Walking Study Methods (Tully et al.):

Participants for article 3 were recruited if they had an acute (< 7 days) grade 1 or 2 ankle sprain, and were between the ages of 16 and 65. Each subject was randomly allocated to a group: either the standard group (received standard RICE treatments – N=16) or an exercise group (additional early therapeutic exercises emphasizing range of motion – N=16). From here, each person was fitted with an accelerometer to record their levels of physical activity (they were asked to wear it for 7 consecutive days). Additionally, each subject included was subjectively analyzed using the Lower Extremity Functional Scale (LEFS) and a 100mm VAS.

Each patient was advised on the application of ice and compression for the 7 day period. At baseline, they were encouraged to walk within the limits of their pain for 7 days. Crutches, bandages and other external supports were not provided. Participants allocated to the exercise group were given rehabilitation exercises and were advised to perform the exercises 3x/day for 1 week. They were non-weight bearing, and focused on the improvement of ankle ROM and strength. They were also given a DVD demonstrating each exercise (the specific exercises were not given, and the reader was referred to the published study protocol [1]).

A non-injured control group was formed for comparison. They were deemed physically healthy, and free from medical condition or chronic disease which may decrease their ability to perform their abilities of daily living. These subjects were also fitted with accelerometers, and were asked to perform their normal ADLs.

For each group, the number of individual steps, time spent sitting, standing and walking, the number of times the subject stood up/sat down, energy expenditure and the amount of time they spent in light, moderate and high intensity exercise. Patterns of physical activity were measured, based on the number of bouts of short (< 20 continuous steps), moderate (20-100 continuous steps), long (> 100 continuous steps) and extra-long walks (> 500 continuous steps) and on the cadence of each.

Study Strengths / Weaknesses:

Weaknesses:
  • An inherent problem with the development of clinical guidelines is that not every issue around a topic has been proven with high-quality research. Because of this, many concepts remain open for debate and many decisions are based on consensus and interpretation of a body of evidence.
  • It is unclear as to what exactly the researchers who performed the walking volume study were measuring. Both groups were encouraged to walk within the confines of their pain, while the exercise group was encouraged to perform specific (and non-described) non-weight bearing exercise. The exercise group walked more often, harder and at a greater cadence than the standard treatment group. I interpret this evidence as carefully chosen exercises emphasizing range of motion, in combination with walking within the confines of one’s pain is important for not only healing, but to dispel any fear or apprehension the patient might have following an injury. What exactly is the authors’ operational definition of optimal loading in this study? Is it walking or early range of motion exercise?
Strengths:
  • The authors of the guidelines used a good strategy to grade the articles and disclosed admirably when their suggestions were based on consensus and not hard science.
  • The authors of the optimal loading study set the stage for further research by determining what an average baseline is for individuals who suffer a lateral ankle injury.

Additional References:

  1. Fong DT, Hong Y, Chan LK et al. A systematic review on ankle injury and ankle sprain in sports. Sports Med 2007; 37: 73–94.