A note on this column: This article is general medical information, not a description of a service offered at this practice. Dr. Ishiguro's surgical practice is focused on hip and knee conditions — he does not treat ankle sprains or other foot and ankle ligament injuries. This column is written to help readers understand a very common injury and know when and how to seek the right specialist, typically a foot and ankle orthopaedic surgeon, sports medicine physician, or physiotherapist.
What actually happens when you "sprain" an ankle
An ankle sprain is a tear — partial or complete — of one or more of the ligaments that stabilise the ankle joint. The overwhelming majority are lateral ankle sprains, caused by the foot rolling inward (inversion) while the ankle is pointed downward, a position in which the outer ligaments are least protected. This is the classic "I stepped off a curb wrong" or "I landed awkwardly after a jump" mechanism.
Three ligaments make up the lateral ligament complex, and they fail in a predictable order as the force of the injury increases. The anterior talofibular ligament (ATFL) is the weakest and most frequently torn, often in isolation in milder injuries. With greater force, the calcaneofibular ligament (CFL) tears as well. The posterior talofibular ligament (PTFL) is the strongest of the three and is rarely injured except in severe ankle trauma, such as a dislocation. A distinct and less common injury pattern — the high ankle sprain — involves the syndesmosis, the fibrous connection between the tibia and fibula above the ankle joint itself; this pattern behaves differently, tends to take longer to heal, and is more often seen in contact and cutting sports.
| Grade | Tissue damage | Typical findings |
|---|---|---|
| Grade I | Stretch or microscopic tearing | Mild swelling, minimal instability, able to bear weight |
| Grade II | Partial ligament tear | Moderate swelling and bruising, some laxity, painful weight-bearing |
| Grade III | Complete ligament rupture | Significant swelling and bruising, mechanical instability, difficulty bearing weight |
How common this is, and who it happens to
Ankle sprains are among the most frequent musculoskeletal injuries seen in emergency departments and sports medicine clinics, with population-based estimates in the range of roughly 2–7 sprains per 1,000 people per year, and considerably higher rates in sports involving jumping, cutting, and contact with another player's foot — basketball, volleyball, and football/soccer are consistently the highest-risk sports. A prior sprain is the single strongest risk factor for a future one, which is part of why the injury has a reputation for recurring.
Recognised risk factors
- Previous ankle sprain — the single strongest predictor of a future sprain
- Sports involving jumping, pivoting, or landing on an uneven surface — basketball, volleyball, football/soccer, trail running
- Reduced proprioception or balance control — often a residual effect of an earlier, incompletely rehabilitated sprain
- Footwear and playing surface — irregular terrain and poorly supportive shoes increase risk
- Ligamentous laxity or anatomical factors — such as hindfoot varus alignment
- Inadequate rehabilitation after a prior injury — returning to activity before strength and balance have recovered
What the evidence shows: A systematic review of studies using validated self-report tools found that chronic ankle instability — recurrent giving-way and a subjective feeling of instability after the acute injury has otherwise healed — develops in roughly a quarter of the general population with any history of ankle sprain, and in closer to 46% of people specifically selected for having a prior sprain, with rates highest among adolescents. The wide range across studies (7–76%) reflects differences in how instability was defined and measured, but the consistent message is that a meaningful proportion of "simple" sprains do not fully resolve on their own (Lin et al., Journal of Foot and Ankle Research, 2021).
How the diagnosis is made — and whether you need an X-ray
Most ankle sprains are diagnosed clinically: a history of an inversion injury, tenderness over the ATFL and/or CFL, swelling, and bruising that may take a day or two to fully appear. Special tests such as the anterior drawer test (assessing ATFL competence) and talar tilt test (assessing CFL competence) can help gauge the degree of instability, though they are most reliable a few days after the injury once acute muscle guarding has settled.
The more immediate clinical question in the emergency room or clinic is usually not "which ligament tore" but "is there a fracture." This is where the Ottawa ankle rules, a simple bedside decision tool developed in the early 1990s, are used worldwide to decide who actually needs an ankle X-ray: imaging is recommended only if there is bone tenderness at specific points on the malleoli or midfoot, or an inability to bear weight for four steps both immediately after the injury and in the clinic.
What the evidence shows: A 2022 meta-analysis pooling 15 studies of the Ottawa ankle rules in adults found a pooled sensitivity of 0.91 (95% CI, 0.89–0.92) for detecting fracture, meaning the rule is very good at identifying which patients are unlikely to have a fracture and can safely avoid an X-ray. Specificity was much lower, at 0.25 (95% CI, 0.24–0.26) — a positive result (i.e., meeting the criteria for imaging) does not mean a fracture is present, only that one cannot be confidently excluded without a film. In practice, this makes the rule most useful for ruling fractures out rather than ruling them in, and it should be applied alongside clinical judgment rather than as a strict substitute for it (Gomes, Chau, Banwell & Causby, BMC Musculoskeletal Disorders, 2022).
When a fracture has been excluded but the injury seems more severe than expected, or symptoms are not settling on the anticipated timeline, MRI can characterise the extent of ligament, cartilage, and syndesmotic injury more precisely — though it is not a routine part of the initial work-up for an uncomplicated sprain.
What the evidence says about early treatment
The old advice for a sprained ankle was strict rest and immobilisation in a cast or rigid boot. That guidance has shifted substantially over the past two decades toward functional treatment — early protected movement, weight-bearing as tolerated, and a structured rehabilitation programme, typically supported by a lace-up brace or semi-rigid ankle support rather than a cast. The rationale is that controlled early loading and motion promote ligament healing, preserve proprioception, and prevent the muscle wasting and joint stiffness that prolonged immobilisation can cause.
Commonly used treatment components
- Protection and early controlled loading — a lace-up or semi-rigid brace rather than a rigid cast, allowing protected movement from the first days
- Ice, compression, and elevation — for the first 48–72 hours, to limit swelling
- Early range-of-motion and progressive weight-bearing — as pain allows, rather than strict rest
- Balance and proprioceptive training — a central component of rehabilitation, since impaired proprioception is a key driver of re-injury
- Progressive strengthening of the peroneal (ankle-evertor) muscles — improves dynamic joint control
- Bracing during return to sport — commonly continued for a period after return to reduce recurrence risk
What the evidence shows: Earlier evidence, including a widely cited Cochrane review, concluded that functional treatment produced better outcomes than rigid immobilisation for acute lateral ankle ligament injuries. A more recent 2025 systematic review and meta-analysis of 10 randomised trials (1,133 patients) comparing functional treatment with immobilisation found no statistically significant difference between the two approaches in patient-reported pain or function at follow-up. Taken together, the evidence base has evolved: functional treatment is still generally preferred in clinical practice because it avoids the downsides of prolonged immobilisation (stiffness, muscle atrophy, delayed return to activity) without appearing to compromise the ligament-healing outcome itself, but the size of any advantage over immobilisation appears more modest than earlier literature suggested (Vílchez-Cavazos et al., Journal of Bodywork and Movement Therapies, 2025).
For most Grade I and II sprains, this combination of protection, early movement, and structured rehabilitation leads to a return to daily activity within 1–2 weeks and to sport within 4–8 weeks, though full proprioceptive recovery can take longer than the pain does — which is precisely why sprains that feel "better" are so often re-injured when rehabilitation is cut short.
When a sprain doesn't fully heal: chronic ankle instability
A subset of patients continue to experience recurrent giving-way, a sense of the ankle "not being trustworthy," and repeated re-sprains months to years after the original injury — a condition known as chronic ankle instability. This can result from incompletely healed or elongated ligaments (mechanical instability), impaired neuromuscular control and proprioception (functional instability), or, commonly, a combination of both. The first-line approach remains non-surgical: a structured course of balance and strengthening rehabilitation, often for a minimum of several months, before surgery is considered.
When conservative rehabilitation genuinely fails and instability continues to interfere with daily activity or sport, surgical ligament repair or reconstruction — most commonly the modified Broström-Gould procedure, which repairs and reinforces the native ATFL and CFL — is a well-established option, performed by foot and ankle surgeons either open or arthroscopically.
What the evidence shows: A meta-analysis of eight randomised controlled trials (426 patients) compared the modified Broström-Gould procedure against other surgical techniques (including various augmentation and reconstruction methods) for chronic lateral ankle instability. Across most outcome measures — including ankle stability and complication rates — the two approaches performed similarly, though one functional outcome score (FAOS) favoured the comparison procedures by a modest margin. The overall message is that several well-performed surgical techniques can achieve good, broadly comparable outcomes for chronic instability, and the choice between them is largely a matter of surgeon experience and individual anatomy rather than one technique being clearly superior (Yang et al., BMC Musculoskeletal Disorders, 2022).
| Stage | Typical approach | Notes |
|---|---|---|
| Acute (days 0–14) | Protection, ice/compression/elevation, early motion, brace | Weight-bearing as tolerated; avoid prolonged rigid immobilisation |
| Subacute (weeks 2–8) | Progressive strengthening, balance/proprioceptive training | The stage most often shortened or skipped — and the likely driver of recurrence |
| Chronic instability | Extended rehabilitation trial (typically 3+ months) | Surgery considered only after genuine conservative failure |
| Surgical (Broström-Gould, etc.) | Ligament repair or reconstruction | Reserved for persistent instability affecting function or sport |
When to see a specialist
A same-day evaluation is warranted for an ankle injury with obvious deformity, inability to bear any weight at all, numbness, or a visibly unstable joint. For a typical sprain, seeking assessment within the first few days is reasonable if swelling and pain are more severe than expected, if there is bone tenderness rather than just soft-tissue pain, or if you're unsure whether a fracture has been excluded. For anyone with a pattern of repeated sprains or a persistent sense that the ankle "gives way," a foot and ankle specialist or sports medicine physiotherapist can assess whether structured rehabilitation — or, less commonly, surgery — is the right next step.
References (PubMed / Journal)
Gomes YE, Chau M, Banwell HA, Causby RS. Diagnostic accuracy of the Ottawa ankle rule to exclude fractures in acute ankle injuries in adults: a systematic review and meta-analysis. BMC Musculoskelet Disord. 2022;23(1):885. DOI: 10.1186/s12891-022-05831-7
Lin CI, Houtenbos S, Lu YH, Mayer F, Wippert PM. The epidemiology of chronic ankle instability with perceived ankle instability: a systematic review. J Foot Ankle Res. 2021;14:41. DOI: 10.1186/s13047-021-00480-w
Vílchez-Cavazos F, Quiroga-Garza A, Acosta-Olivo CA, Rodríguez-Corpus LA, Espinosa-Uribe AG, Peña-Martínez VM, Simental-Mendía M. Functional treatment versus immobilization for the management of acute ankle sprains: a systematic review and meta-analysis. J Bodyw Mov Ther. 2025;44:48-55. DOI: 10.1016/j.jbmt.2025.05.035
Yang Q, Liu J, Liu C, Zhou P, Zhu D. Modified Brostrom-Gould surgical procedure for chronic lateral ankle instability compared with other operations: a systematic review and meta-analysis. BMC Musculoskelet Disord. 2022;23:981. DOI: 10.1186/s12891-022-05957-8