Treatment of acute ankle ligament injuries: a systematic review

Today, surgical treatment plays only a minor role for the treatment of acute ankle sprains. In most narrative review articles non-operative treatment is recommended [10, 11, 14, 40].

However, a Cochrane review [26] has shown that surgical ligament reconstruction is advantageous with regard to the recurrence rate for ankle injuries, the incidence of chronic ankle problems and functional (subjective) and mechanical (objective) instability of the ankle. On the other hand, there was limited evidence for longer recovery times, higher incidences of ankle stiffness, impaired ankle mobility and more complications in the surgical treatment group. Because of the low quality of the analyzed trials, the authors concluded that there is insufficient evidence to determine the relative effectiveness of surgical and conservative treatment for acute ankle sprains.

Two later published prospective randomized trials came to similar findings. In a randomized study with a long-term follow-up, Pihlajamäki et al. [44] could show that surgery decreased the prevalence of reinjury of the lateral ligaments. A downside for surgical treatment in this study was a higher rate of II degree of osteoarthritis detected by MRI. Takao et al. [51] have shown in a randomized study with a 2 years follow-up that functional treatment alone had an approximately 10 % failure rate and a slower return to full athletic activity.

In both studies [44, 51], there was no difference in the clinical scores between surgical and non-surgical treatment.

Based on these findings, we conclude that the main advantage of surgical ankle ligament repair is that objective instability and recurrence rate was less common when compared with non-operative treatment. Balancing the advantages and disadvantages of surgical and non-surgical treatment, we conclude that the majority of grades I, II and III lateral ankle sprains can be managed without surgery. However, with regard to its advantages, surgery should not be totally abandoned. The indication for surgical repair should be made on an individual basis. We agree with van den Bekerom et al. [52] that an acute reconstruction could be indicated in athletes, because increased objective instability is a predictor for future ankle sprains [59].

Another indication for surgery could be an extensive grade III lesion of all three lateral ankle ligaments with massive hematoma [4, 42].

This question can be answered by the meta-analysis published by Kerkhoffs et al. [24]. Based on the analysis of 21 trials involving 2,184 participants these authors concluded that functional treatment appears to be the favourable strategy for treating acute ankle sprains when compared with long-term immobilization (4–6 weeks). However, these results should be interpreted with caution, as most of the differences are not significant after exclusion of the low quality trials. Many trials were poorly reported and there was variety amongst the functional treatments evaluated.

Two newer randomized controlled studies, however, found that for the treatment of grade III injuries a short period (10 days) of immobilization with a below knee cast can be advantageous [5, 6, 27].

Probably, a short period of rest in a below knee cast helps to reduce swelling and pain during the early inflammatory phase of biological ligament healing. Later during the proliferation phase and remodeling phase, immobilization in a cast could be detrimental for the healing process. According to the principle of causal histiogenesis [41] functional stress is needed for the remodeling of connective tissue. It is also well known that prolonged immobilization has a detrimental effect on muscles, ligaments and joint surfaces.

Therefore, several authors recommend that initial treatment during the inflammatory phase should be directed towards avoiding or diminishing excess swelling and ongoing injury, thus optimizing the healing process [11, 14, 53]. RICE (Rest, Ice, Compression and Elevation) therapy is considered to be the treatment of choice for the first 4–5 days to reduce pain and swelling [53] and prefer a short initial period of 5–7 days (max 10 days) of immobilization in a below the knee cast or removable boot.

It is generally agreed that the majority of acute grade I–III ankle sprains can be treated by non-operative measures.

During the proliferation phase, the tissue responds with vascular ingrowth, fibroblast proliferation and new collagen formation. Protection of inversion is important during this phase of healing to prevent excess formation of weaker type III collagen formation that can contribute to chronic elongation of the ligament. Controlled stress on the ligament will promote proper collagen fibre orientation. In addition, motion, stretching and strengthening will avoid the harmful effects of immobilization on the muscle, joint cartilage and bone.

We differentiate several options for external ankle protection: bandages, tape, lace up braces and semi rigid ankle orthoses. In a meta-analysis, Kerkhoffs et al. [25] have shown that the use of an elastic bandage has fewer complications than taping, but appears to be associated with a slower return to work and sport, and more reported instability than a semi-rigid ankle support. Lace-up ankle support appears to be effective in reducing swelling in the short-term compared with semi-rigid ankle support, elastic bandage and tape [25].

Newer randomized trials came to similar results. In all studies patients had better short term results with a semi-rigid ankle brace than with a bandage [5, 7, 9, 27]. Lardenoye et al. [28] compared a semi rigid brace with tape. In this study, the rate of skin complication in this group was significantly lower as compared to the tape group, but functional outcome of the ankle joint was similar between the two treatment groups, as well as reported pain. Bennyon et al. [5] showed that even for grades I and II injuries treatment with a semi rigid ankle brace combined with an elastic wrap returned subjects to normal walking and stair climbing in half the time required for those treated with the Air-Stirrup brace alone form those treated with an elastic wrap alone.

From these studies, we conclude that during the proliferation phase the ankle is most effectively protected against inversion by a semi-rigid ankle brace. For grade III injuries, the semi-rigid orthosis is adapted after the initial short immobilization phase.

All studies about non-surgical treatment of ankle sprains have one methodological flaw, because they report only short-term follow-up data and no resprain rates. Malliaropoulos et al. [29] reported with a cohort study a resprain rate of 17.8 % at 2 years after non-operative ankle sprain treatment. Because of this methodological flaw, we do not know the resprain rates of different types of different types of external support for the treatment of ankle sprains. More prospective randomized studies with a longer follow-up are needed to answer this question.

In 1965, Freeman [15, 16] hypothesized that balance and coordination training could diminish proprioceptive deficits associated with ligamentous injury to the ankle. Contemporary theory suggests that balance and coordination training may have both local and central effects on the sensorimotor system [19, 45, 46]. However, consensus is lacking regarding the clinical evidence of the efficacy and effectiveness of these interventions. In contrast to the hypothesis of Freeman, a previously published systematic review [40] reported that there was no evidence for effectiveness of physiotherapy as a treatment strategy for acute ankle sprains.

Two randomized controlled trials published later, however, reported fewer resprains after 12 months follow-up [20, 62].

Even the results of the studies analyzed in this systematic review are contradictory. Van Rijn et al. [56] found that conventional treatment of an ankle sprain combined with supervised exercises as compared to conventional treatment alone after an acute lateral ankle sprain does not lead to differences in the occurrence of resprains or in subjective recovery. Bleakley et al. [6] could also detect no difference in the resprain rate between the groups with and without exercise after an acute ankle sprain. However, this study showed a positive effect of exercise for improved ankle function and activity. The 2Fit study, however, showed a positive effect of a non-supervised home-based proprioceptive balance board training program in addition to usual care on the resprain rate Hupperets [22]. A process evaluation showed that only 23 % of the intervention group indicated to have fully adhered with the neuromuscular training program. Significantly fewer recurrent ankle sprains were found in the fully adherent group compared with the group that was not adherent [61]. This could be an explanation for the missing effect in the studies conducted by van Rijn [56] and Bleakery et al. [6]. The power of these studies was with 102 participants each much lower than in the 2 Fit trial with 522 participants.

In conclusion, based on the high level 2 Fit study, we conclude that balance training can be used after an acute ankle sprain in an effort to reduce future ankle sprains.

A meta-analysis about the prevention of ankle sprains published in 2001 [18] found that there was limited evidence for reduction in ankle sprain for those athletes with previous ankle sprains who did ankle disk training exercises.

In this systematic review, we analyzed only studies published between 2002 and 2012. Two of the randomized trials that met the inclusion criteria focused on the primary preventive effect of balance training. In these studies, the ankle sprain rate was significantly lower after balance training only in the group of athletes with a previous sprain [30, 58]. In players without a history of ankle sprains, there was just a tendency towards a lower injury rate in the training group. These studies confirm results of previous studies which were published before 2002 [48, 50]. A sensitivity analysis of Verhagens prevention study [60] showed that only a balance board training program aimed at players with the previous ankle sprains could be cost-effective over a longer period of time.

Probably, more well-designed prospective studies with larger samples are needed to show a significant effect also for athletes without a previous ankle sprain. However, even if these studies could show an effect, the number to treat is expected to be high.

These findings can be explained since the most important risk factor for an ankle sprain is a previous ankle sprain [13]. This might be due to reduced proprioceptive function [35, 36, 38]. Mitchell et al. [35, 36] have demonstrate a slower reaction time and postural sway deficits in ankles with functional instability. These authors concluded that individuals, who sustain an acute ankle sprain and those with functional instability require rehabilitation that improves proprioception, strengthens the evertors and dorsiflexors, and restores peroneal reaction time.

In conclusion, in accordance with a previous systematic review [39], the articles published between 2002 and 2012 provide evidence that a balance training can be used in an effort to reduce future ankle sprains in athletes with a previous injury.

Three of the four identified studies showed that the use of lace up braces reduced the incidence, but not the severity of acute ankle injuries in football and basketball players [2, 30, 31]. One study compared prophylactic bracing or taping in high school football [33]. In this study, there was no difference in the rate of ankle sprains between the two groups. However, the cost analysis showed that tape use was less cost-effective (more time) than brace use.

These results confirm results of a meta-analysis which was published in 2001 [18]. This meta-analysis provided good evidence for the beneficial effect of ankle braces to prevent ankle sprains during high-risk sporting activities (e.g. soccer, basketball).

In conclusion, there is good evidence from high level randomized trials in the literature that the use of a brace is effective for the prevention of ankle sprains.

Every effort was made to obtain level one evidence studies to answer our research questions. However, even these high quality studies vary in terms of quality of methodology and reported outcomes.

The problem of the meta-analysis was that many studies that were included had methodological flaws. Therefore, in none of the meta-analysis included in this review, the authors found strong evidence for one of the examined treatment options.

The RCTs about surgical versus non-surgical treatment have an adequate follow-up (2–14 years), but a low number of patients. Therefore, the power of these studies might not be large enough to find out any differences in clinical scores. On the other hand, the RCT about non-surgical treatment of acute ankle sprains have large case numbers, but the follow-up varies between 9 and 12 months. This period is too short to examine resprain rates. Therefore, none of the RCT about non-surgical treatment with external support reports the rate of recurrent sprains. The papers originate from different countries and therefore, may not be applicable in every aspect to all populations. Limiting the review to English language articles only has the risk for high-quality non-English articles to be excluded. We looked only at studies which recruited adults. Therefore, the results are not applicable for the treatment of ankle sprains of children (i.e. 18 years or older).

Owing to the limitation of our search RCTs about pharmacolocgical treatment of ankle sprains were excluded. This was done to limit the scope of this systematic review. Many studies deal with the use of NSAIDs, for example. A new treatment option is the use of hyaluronic acid injections that should be associated with a more rapid return to sport and with only a few associated adverse events, but the relative increased cost of this treatment versus the standard of care has to be considered [43].

Despite the existing evidence from meta-analysis and RCT, many patients develop chronic problems after injury of the ankle ligaments [17, 29, 55, 57]. Therefore, there is reason to believe that many question for the treatment of ankle injuries are still unsolved. These unresolved issues include time and criteria for return to sports, duration of ankle protection by external support, use of and diagnostics of associated injuries.