Talocrural Joint Laxity and Range-of-Motion Following an Acute Lateral Ankle Sprain

By Bethany A. Wisthoff, PhD, ATC; Carrie L. Docherty, PhD, ATC, FNATA; Joseph J. Glutting, PhD; Geoffrey P. Gustavsen, MD; Todd D. Royer, PhD; Charles B. Swanik, PhD; and Thomas W. Kaminski, PhD, ATC, FNATA, FACSM

The many articulations of the human ankle joint can be easily disrupted by “a mere sprain.” This research examines 2 specific deficits and their impact in the 6 months after an initial sprain.

Ankle sprains account for a large number of acute sport-related injuries presenting to the emergency department with a cost of over $1,000 per lateral ankle sprain.¹ The ankle joint is the most common injured body site in an athletic population. The sports with the highest prevalence of ankle sprains have been reported as men’s and women’s basketball, as well as women’s track, women’s soccer, and women’s field hockey. The amount of time to return to full activity has been previously reported with 44% returning less than 24 hours from the injury and only 3.6% requiring more than 21 days before returning to play.²

In a general clinic-based population, approximately 72% of patients following an ankle sprain reported residual symptoms 6 to 18 months later.³ Of those that reported residual symptoms, 40% reported at least one moderate to severe symptom, which included: perceived ankle weakness, perceived ankle instability, pain, and swelling. Factors that were associated with moderate to severe symptoms were re-injury of the ankle, activity restriction longer than one week, and limited weight bearing longer than 28 days.³

A reduction in dorsiflexion range-of-motion (DFROM) after an ankle sprain has been identified as a strong injury predictor, leading to a subsequent ankle sprain.⁴ Previous research has determined that this deficit may result from an anterior displacement of the talus or loss of posterior talar glide.⁵ As deficits in range-of-motion occur after an ankle sprain, deficits in talocrural  joint laxity also occur.⁶

Laxity, or the amount of mechanical instability within the joint, has been previously identified as an indicator of subsequent injury to the ankle ligaments.⁷ After an initial evaluation of the injury occurs, the clinician will grade the injury (I, II, III) depending upon the severity of the injury and the symptoms presented. Grading, typically, will occur following manual stress tests, such as the anterior drawer test and talar tilt test.⁸ Manual stress tests have been shown to be less reliable in determining laxity within the joint, thus making the grading of injury severity less accurate.⁹ This can be problematic, since understanding the severity of an ankle sprain plays a significant role in the clinician’s reasoning for specific rehabilitation protocols and time to return-to-play. Therefore, the purpose of recent research–Identifying range-of-motion deficits and talocrural joint laxity after an acute lateral ankle sprain published by our group in the Journal of Athletic Training–was to compare mechanical laxity of the talocrural joint and dorsiflexion range-of-motion in an athletic college-aged population over time after an acute ankle sprain.¹⁰

Methods

This cross-sectional study recruited 108 volunteers who were divided into 2 groups: those who sustained an acute ankle sprain (AAS= 55) and a control group of those who had had no ankle sprain (CON= 53). Ankle sprain was defined per the International Ankle Consortium endorsed definition: An acute traumatic injury to the lateral ligament complex of the ankle joint as a result of excessive inversion of the rear foot or a combined plantar flexion and adduction of the foot that usually results in some initial deficits of function and disability.

Ankle laxity and ROM were assessed for the AAS group at 24–72 hours, 2–4 weeks, and 6-months post-ankle sprain (see Figure 1 for details). The CON group was assessed in all outcome measures once to compare to the AAS group. Within the AAS group, 44 of the 55 (80%) were Division I or II competitive athletes that received initial treatment within 24–72 hours and progressive rehabilitation by a certified athletic trainer (AT). The remaining 20% were recreational non-competitive athletes that received initial evaluation by a physician within 24–72 hours but did not have progressive rehabilitation by an AT; however, these athletes still returned to physical activity following the ankle sprain.

Results

Of those who sustained an acute lateral ankle sprain, 21 of 55 (38%) were Grade I, 27  (49%) were Grade II, and 7 (13%) were Grade III. While DFROM improved over time, a more significant improvement was seen between the first and second visits, with a a smaller improvement noted at 6-months. In Grade III ankle sprains, DFROM was more severely compromised compared to Grade I within the first 24–72 hours. Laxity using an inversion length measurement (Figure 2) showed a significant difference between 2–4 weeks and 6 months. Laxity improved in inversion at 2–4 weeks; however, when compared with the CON group, an increase in inversion length was noted at 6-months post-sprain. Similar differences were noted in anterior drawer direction as well. As sprain severity increased from I to III, inversion length increased sequentially as well. The largest differences between the severity groups were seen at 24–72 hours post-sprain.

The weight-bearing lunge test (WBLT; Figure 3) was not conducted at 24–72 hours. At 2–4 weeks, the WBLT results in degrees approached differences by severity, yet the centimeter measure did not differ. Conversely, at 6 months, the WBLT result in centimeters approached differences by severity, yet the result in degrees did not differ.

Discussion

The long-term effects of an acute lateral ankle sprain on ankle joint laxity and ankle joint function have not been previously identified in a college-age population compared to a healthy uninjured cohort. This study sought to compare mechanical laxity of the talocrural joint in this population over time after an acute ankle sprain. The primary findings showed that, at 6 months following an acute ankle sprain, significant differences in laxity do exist when compared to a healthy control group.

Previous research is limited on the differences observed in the WBLT and DFROM results across severity of ankle sprain.¹¹ As DFROM improves over time in those with an AAS, it may be important to consider the difference between the injured and uninjured limb as well over time. In a Grade II or III ankle sprain, the structure of the anterior talofibular ligament (ATFL) has been disrupted and during the remodeling phase, scar tissue is built up around the repairing ligament.¹² This scar tissue is less mobile than an intact ligament. Previous work concluded that this may cause a shift in the position of the talus such that it may sit more anteriorly, causing a decrease in DFROM of the ankle.⁵ We postulate this to be the reason for a decrease in the WBLT found in those with a Grade II or III ankle sprain. The WBLT measures DFROM in a weight-bearing position and has previously been accepted as a reliable method of measuring DFROM over a goniometric measurement in a non-weight-bearing position.¹³ We contend that the WBLT is important to utilize and monitor in those who sustain a Grade II or III ankle sprain to make sure differences do not exist over time.

Similar to previous research, in the present study, talofibular interval (difference of the stressed to static position on the ultrasound image) significantly reduced from 24–72 hours to 2–4 weeks following the injury. However, the interval at 6 months was closer to 24–72  hours post-sprain, meaning that the improvement of the stability of the ankle joint may not sustain to 6 months or longer. This previous research, however, did not use a control or healthy group for comparison. They used the opposite, uninvolved ankle for comparison. The time points used also extended the time at baseline which was less than 7 days from injury and up to 6 weeks from the injury. In our study, a 6-month time point was used to determine long-term effects of ankle laxity noted via stress ultrasonography.

The International Ankle Consortium has developed recommendations for clinical assessment of acute lateral ankle sprain injuries, based on expert consensus. The Rehabilitation-Oriented ASsessmenT (ROAST) includes assessment of the patient’s ankle in multiple areas: joint pain, magnitude of joint swelling, range-of-motion, arthrokinematics, strength, static and dynamic postural balance, gait, level of physical activity, and self-reported joint function.¹⁴  Along with establishing the mechanism of injury and assessment of ankle joint bones and ligaments through stress tests, clinicians need to be able to incorporate all previous areas into their assessment of acute lateral ankle sprain injuries.

Conclusions

• Deficits can be noted in those that sustain an AAS at least 6 months following the injury.
• Each sprain may have different impairments that need to be addressed and must be reevaluated after return to full function. Ultimately, in an athletic population, current research is showing that these patients may be returning back to full participation too early, without any follow-up or maintenance rehabilitation, which may lead to incomplete recovery.¹⁵
• We believe that the use of musculoskeletal ultrasound to obtain subjective information can be important to clinicians early in those with a LAS.
• A significant increase in anterior drawer and inversion/talar tilt was noted between the groups 6 months following an acute ankle sprain.
• Between severity, at 24–72 hours, Grade II and III ankle sprains have greater anterior drawer and inversion ATFL length.
• At 2–4 weeks, Grade II ankle sprains have increased inversion length compared to Grade I ankle sprains. Interestingly, this difference at 2–4 weeks may indicate the long-term effects seen between the severity of ankle sprains.

Bethany A. Wisthoff, PhD, ATC, is an assistant professor in the Department of Kinesiology and Applied Physiology at the University of Delaware.

Carrie L. Docherty, PhD, ATC, FNATA, is Executive Associate Dean and Professor in the School of Public Health at Indiana University.

Joseph J. Glutting, PhD, a quantitative psychologist, is a Professor in the School of Education at the University of Delaware.

Geoffrey P. Gustavsen, MD, is a sports medicine family physician in Newark, Delaware.

Todd D. Royer, PhD, is Associate Professor in the Kinesiology & Applied Physiology Department at the University of Delaware.

Charles B. Swanik, PhD, is a Professor in the Kinesiology & Applied Physiology Department at the University of Delaware.

Thomas W. Kaminski, PhD, ATC, FNATA, FACSM, RFSA, is Professor and Director of Athletic Training Education at the University of Delaware.