Effects of soft bracing or taping on a lateral ankle sprain: a non-randomised controlled trial evaluating recurrence rates and residual symptoms at one year

This study was a pragmatic, non-randomised controlled trial.

A total of 164 patients were assessed for eligibility in this study (Figure 2). Seven patients were excluded due to the following reasons: age under 18 years (n = 3), ankle fracture (n = 2), treatment already started before treatment allocation (n = 1) and an eversion ankle sprain (n = 1). The age of the 157 included participants ranged from 18 to 64 years (mean 31.1 years); 88 participants (56%) were male. One hundred (64%) of the reported ALALS occurred during sports participation. On average, the allocated treatment started 6.1 days (SD 2.3) and 5.8 days (SD 2.0) after the initial injury in the brace and tape group, respectively. Baseline characteristics did not differ appreciably between the treatment groups (Table 1).

In our study comparing four-week treatment with a soft brace and ankle tape in participants with ALALS, the one-year incidence of re-injury was comparable in both groups with a risk difference of 3.1% (RR 1.2, 95% CI 0.6 to 2.8). The proportion of participants with re-injuries found in this study (15%) is similar to other studies [13].

For passive stability (ligament stability), using the manual anterior ankle test, a difference between the two treatment groups was found at 52 weeks in favour of the tape group. Passive stability did not differ at baseline, but the test was often performed a couple of days after the initial ankle injury. Thus, it is unknown whether the difference in passive stability already existed before the start of this trial (and the initial ankle injury) or was related to the allocated treatment. In this study, the manual anterior ankle test and talar tilt test were used. The use of these manual tests is difficult to discuss because of their subjective nature, and the inability to produce reproducible and quantitative results [27]. Both manual tests are, however, still frequently used to estimate ankle joint laxity. Several devices have been developed to objectively measure ankle joint laxity; for example, the dynamic anterior ankle tester (DAAT) [28]. At the start of our study, the reliability of this device had been found to be high, but its validity needed further investigation [29]. Furthermore, at the time of the study, the apparatus itself was not suitable for clinical practice [28]. As the manual anterior ankle test and talar tilt test were frequently used in clinical practice, we chose to use these manual tests in this pragmatic trial.

Active stability, or muscular stability, did not differ after one year. Several earlier studies have demonstrated that passive or mechanical stability is related to active stability or functional stability [30,31]. However, a recent study demonstrated the opposite [32]. In 2002, Hertel developed a model of functional and mechanical insufficiency, which can be helpful in explaining the causative spectrum related to Chronic Ankle Instability (CAI) [33]. In this model two subgroups are included, classified according to the presence of either mechanical instability or functional instability. When both mechanical and functional instability are present in a patient, a third subgroup of recurrent ankle sprains arises. In a recent study, Hiller et al. (2011) proposed a modification of the Hertel model for CAI. In the new model mechanical instability, perceived or functional instability, and recurrent ankle sprain can exist independently or in combination, with seven subgroups of patients now differentiated [34]. The results of our trial seem to fit this latest model proposed by Hiller et al. However, it was not our purpose to evaluate the relationship between functional and mechanical ankle instability.

In the early 1990s, Twellaar et al. compared one of the first prototypes of the soft brace with ankle tape [35]. After an average follow-up period of 2.3 years, tenderness at the lateral ligaments occurred more often after applying tape. They concluded that soft bracing might be preferred over ankle taping for practical reasons, with a lower risk for skin irritation being one of these. The results of our study showed that skin irritation was the main reason for not completing the prescribed treatment, especially in the tape group. The percentage of participants who were not compliant to the treatment was almost twice as high in the tape group compared to the brace group (52% to 27%).

Several studies have compared ankle braces with elastic wrapping or Tubigrip™ [18,36,37]. In a recent review, Kemler et al. compared the effectiveness of ankle brace treatment with other functional treatment and classified the evidence for the effectiveness of ankle bracing on functional outcomes as strong [16]. This result was based on studies from Boyce et al. [37], Beynnon et al. [36], Lamb et al. [18], Karlsson et al. [38] and Leanderson and Wredmark [39]. The results of this review seem to contrast with our findings. However, the heterogeneity of these studies should be taken into account. For example, the studies had different follow-up periods, used other types of ankle braces, the ankle brace was compared with treatment methods other than tape, and different outcome measurements were used.

Several limitations of our pragmatic trial should be discussed. Firstly, different application techniques for ankle taping were used by the clinicians involved. The use of different application methods was, however, in line with usual care as described in the guideline of the Dutch College of General Practitioners. In all cases, the tape was applied by a health care professional using the most appropriate method for that patient. Secondly, for logistical reasons, the allocation of participants to the treatment groups was based on the order of presentation, and thus not on a formal randomisation scheme. The comparability of the two groups (Table 1) clearly indicates that our allocation scheme resulted in groups with similar participant characteristics and therefore, similar prognosis. Thirdly, in this study an ‘all complaints’ definition of recurrent ankle sprains was used instead of a ‘medical attention’ or ‘time-loss definition’ [40]. The data may be a good representation of the total burden of ALALS, but their validity may be suspect. Participants were required to judge and decide for themselves whether their new sprain was a re-injury according to the following definition: ‘a re-injury is an ankle sprain (injury) to the same ankle’. As a re-injury was not assessed by a medical professional, no detailed information about the severity of these new injuries was available. Fourthly, an a priori sample size calculation was not performed. A post-hoc power analysis was not performed either because it is controversial regarding its risk of a “power approach paradox”, whereby if a significant difference is not found and a post hoc power analysis is performed after the study, the study will automatically be found to be underpowered. However, it is possible that there is truly no significant difference between the two treatments (i.e. that both treatments are in fact equal to each other). Indeed, our findings indicate that the effects of both treatments are comparable. Although, the 95% confidence intervals are rather wide, so we cannot rule out that our study may have been underpowered and not able to identify smaller differences in treatment effects. Finally, the assessors in our study, the sports physicians, were not blinded to group assignment. The sports physicians had to instruct all participants about the allocated treatment method and had to apply the ankle brace if a participant was assigned to the brace group. We do not expect that this has influenced our results, but we cannot discount the possibility of ascertainment bias. The seven sports physicians who participated in this study were all independent and had no conflicts of interest. Furthermore, the primary outcome was self-reported by the participants.

Our results underline the considerations that both an ankle brace and ankle tape can be used in the treatment of ALALS in primary care. According to Kerkhoffs et al. [41], a lace-up brace or a semi-rigid brace is preferable and recommended in the treatment of ALALS. However, in (professional) sports, the use of tape can also be considered [41]. Van den Bekerom et al. [42] also concluded that either tape, a semi-rigid ankle brace, or a lace-up brace can be used in functional treatment of ALALS.

Functional treatment (including tape, bandage or brace) of ALALS has been recommended instead of surgical repair and plaster cast or splint immobilisation since the early 1990s [14-17]. However, the discussion regarding the use of a short period of immobilisation, followed by functional treatment, exists again [18,41-43]. Additional research focusing on effectiveness of the treatment of ALALS needs to be conducted. In addition, while both the ankle brace and ankle tape can be used for ALALS treatment, an economic evaluation including treatment costs, medical costs and costs due to absence from paid work, unpaid work and school would provide more insight into the cost-related aspects of both treatments.

The results after one-year follow-up indicate that in participants with ALALS, treatment with a soft brace or ankle tape shows similar effects on the incidence of ALALS recurrence and on residual symptoms.