Current concepts in the surgical management of chronic ankle lateral ligament instability

Abstract

Background/aims

Ankle sprains are common injuries which can lead to chronic lateral ankle ligament instability (CAI).

Methods

The aim of this review is to provide a comprehensive overview of the epidemiology, pathophysiology, investigation, surgical management and rehabilitation of CAI.

Results

Investigation of CAI is based on history, clinical examination, and imaging. Surgical management of CAI can be defined as anatomic reconstruction, anatomic and non anatomic repair of ATFL and/or CFL. Anatomic repair has been shown to have better functional outcomes and less secondary osteoarthritis when compared to non anatomic repair. Non-anatomic methods do not replicate the normal anatomical course of ATFL/CFL and may lead to stiffness. The most common surgical treatment for CAI is the open modified Broström repair augmented with the Gould modification. There are arthroscopic techniques being developed which have reported promising clinical results. However, there are considerable areas of further research which should be carried out to improve understanding and effectiveness of current treatment options. Standardised validated patient reported outcome measures and evidence-based protocols in the rehabilitation periods are crucial for positive and reproducible outcomes.

Conclusion

Surgical repair has proven to show excellent outcomes for patients suffering from CAI, however larger prospective studies should be carried out to evaluate the use of newer surgical techniques.

1. Introduction

Chronic lateral ligament ankle instability (CAI) is the development of clinical and functional deficiency within the ankle joint after acute ankle injury.^1,2 Acute lateral ankle instability becomes chronic when the ankle cannot return to its normal function performance and mechanical stability 6 weeks post injury, if the torn ankle ligament(s) have not healed correctly or with the correct tension.³ The mechanical instability and laxity caused by CAI can lead to subsequent dysfunction and pain within the ankle joint.¹

Physically active individual are at higher risk of sustaining acute ankle sprains^4,5), which are common musculoskeletal injuries characterised by the damage or stretching of the lateral ankle ligaments; predominantly the anterior talofibular ligament (ATFL) and the calcaneal-fibular ligament (CFL).^4,6, 7, 8 CAI may develop following the initial ankle sprain, or after recurrent injuries (^4,5

The International Ankle Consortium described seven subsets of chronic ankle instability, but broadly it can be classified as either mechanical or functional instability.⁹ Mechanical dysfunction is based on physical and radiological examination and is due to ligament laxity causing abnormal motion of the talus in relation to the ankle mortise.^3,10

Functional instability is caused by muscle weakness, neuromuscular or proprioceptive defects, without increased ligament laxity.^10,11 Diagnosis of functional instability is dependent on patient signs and symptoms. It requires clinical assessment¹², as the treatment options differ. Arthroscopic evaluation of patients with functional instability has demonstrated morphologic ATFL abnormality despite no demonstrable abnormal lateral laxity, and there is evidence to suggest that a degree of microinstability due to a deficiency of the ATFL could explain functional instability.^13,14

2. Pathophysiology of chronic ankle instability

Damage to ATFL and CFL is often caused by forceful ankle plantar flexion, and lateral inversion.^3,15 Over three quarters of acute ankle sprain cause damage to ATFL, owing to its anatomical position and as it is the weakest ligament within the ankle joint.¹⁶ Other potential lateral ankle ligament injuries include calcaneofibular ligament and posterior talofibular ligament injuries. Syndesmotic injuries (anterior - inferior tibio fibular ligament, posterior - inferior tibio fibular ligament tears) and medial collateral ligament (deltoid ligament) injuries are less likely to occur.¹⁶

Common examination findings include instability upon stress testing (assessed radiographically or clinically) and tenderness over the ligament(s) affected, or evidence of weakness and/or subluxation around the tendoachilles ligamentous complex.^3,17 Anterior drawer testing assesses the competency of the anterior talofibular ligament and Romberg's Manoeuvre aids to assess proprioception abnormalities.³ The patient should also be assessed for associated injuries and foot deformities.¹⁸

2.1. Pathologies associated with CAI

Chronic ankle instability is associated with a range of other pathologies19, 20, 21, 22, including osteochondral defects, ankle impingement and peroneal tendinopathy. Studies indicate that over 50% may have associated peroneal tendinopathy23, 24, 25 whilst a smaller proportion of patients have associated tibialis posterior tenosynovitis and sinus tarsi syndrome.¹⁹ Pre-existing deformities such as cavovarus hindfoot deformity and fibula malalignment also predispose individuals to the development of CAI.26, 27, 28

Development of CAI is associated with neuropraxia, intra-articular loose bodies and fractures of the lateral talar process or fibula.^17,19 Ankle osteoarthritis can develop as a consequence of CAI, with lateral ankle sprain contributing to 80% of posttraumatic osteoarthritis cases.²⁹

3. Radiological investigations

Imaging is a key component in the assessment of CAI. Radiographs, Ultrasound (US) and Magnetic resonance imaging (MRI) can all be used in the diagnosis of chronic lateral ankle ligament injury.30, 31, 32

3.1. Radiographic assessment

Radiographic ankle stress testing should be performed by measuring the distance between the posterior aspect of the tibial articular surface and the talar dome during anterior draw testing. However, false negatives caused by muscle contraction, and functional ankle instability may show normal stress radiographic outcomes, reducing the reliability of its use.³³ Ankle mortise radiographs may be taken to perform the talar tilt test (Fig. 1). Varus stress is applied to the foot and the angle between the articular surface of the distal tibia and talar dome is measured.³ Weight bearing radiographs also help to exclude bony pathologies and arthritis.

Fig. 1.

Radiograph stress testing demonstrating talar tilt indicative of ATFL pathology.

3.2. Magnetic resonance imaging

MRI can confirm the presence of chronic ligamentous injury, osteochondral lesions or other soft tissue pathology.^34,35 A recent systematic review demonstrated high diagnostic accuracy in its use for the diagnosis of ATFL lesions³⁶, with a diagnostic sensitivity and specificity of 1.0 (95% CI: 0.58–1) and 0.9 (95% CI: 0.79–0.96) respectively.³⁶

3.3. Ultrasound imaging

US is also used in the diagnosis of chronic ankle instability and is almost as sensitive as MRI for the assessment of soft tissue ankle injuries, with an accuracy of 91% in the diagnosis of ATFL injuries, compared to 97% with MRI.37, 38, 39

4. Epidemiology of chronic ankle instability

In the UK the prevalence of ankle sprains is 52.7 per 10,000, compared to 21.5 per 10,000 in the US. A systematic review demonstrated a 25% prevalence of CAI amongst the general population with an overall prevalence of 46% (range 40–70%) when participants had a previous history of ankle injury.40, 41, 42

The incidence of acute ankle sprain decreases with age, although there is a difference in peak incidence between genders.⁴³ Acute ankle sprains have a higher incidence amongst males, with a peak of acute ankle sprain incidence in 15–19 year old males compared to a peak incidence of 10–14 year old females.⁴³

4.1. Chronic ankle instability in adolescents

In the general population 10–19 year olds are at the greatest risk of acute ankle sprain.⁸ Severe ankle injuries predispose children to ongoing mechanical and functional instability, with children who engage in dance being more likely to sustain functional instability.⁴⁴

4.2. Chronic ankle instability in athletes

Acute ankle sprains, leading to chronic ankle stability, has a high prevalence amongst the sporting population.^9,43 A large proportion of acute ankle sprains caused by sporting injuries are recurrent (12–47%).^1,7 The function of the ankle can take 3 years to improve and get back to 80 to 90% in elite football players.

4.3. Chronic ankle instability in military personnel

There is also a high incidence of ankle sprain amongst military personnel (up to 58.4 per 1000 people per year), with a high recurrence rate of ∼40%.45, 46, 47

5. Clinical and patient reported outcome measures

Quantifying the severity of ankle instability is important in the assessment of management and treatment.³⁴ The international ankle consortium suggests the use of the foot and ankle ability measure (FAAM) and the foot and ankle outcome score (FAOS) to evaluate functional limitations.⁶ Although these tools are subjective and based on patient reported outcomes, a cross sectional study⁴⁸ supports their use to reliably evaluate postural control and muscle strength in patients with CAI. Currently, the most common clinical outcome assessment tools used to evaluate CAI surgical outcomes are the American Orthopaedics Foot and Ankle society score (AOFAS), the Cumberland Ankle Instability Tool, followed by the Karlsson score (33%).^49,50 In addition, the Visual analog scale (VAS) allows patients to rate their perceived ankle instability on a scale from 0 to 100. Functional performance testing, such as return to activity rates is also a useful measure of outcome.⁵¹

6. Timing of surgery for lateral ankle instability

Conservative approaches are trialled within the first 2 months. Physiotherapy and orthotics are both utilised during rehabilitation with additional neuromuscular and proprioceptive training.⁵² Surgical management is considered when chronic ankle instability persists between 3 and 6 months and fails to respond to conservative methods.⁴¹

7. Surgical management of chronic ankle instability

Surgical management of CAI can be defined as anatomic reconstruction, anatomic and non anatomic repair of ATFL and/or CFL. Non-anatomic methods do not replicate the normal anatomical course of ATFL/CFL and may lead to stiffness.^53,54 Anatomic repair involves the use of endogenous ligament tissue for ligament repair⁵⁵). An example is the open modified Broström lateral ligament reconstruction, which is the currency preferred mainstay of surgical treatment, as it is associated with better functional outcomes and less secondary osteoarthritis when compared to non anatomic repair.⁵⁶

8. Open modified Broström lateral ankle ligament repair

The open modified Broström procedure consists of retensioning of damaged ATFL and CFL with reinforcement and is the gold standard in repairing CAI.⁵⁷ The initial Bostrum repair was described in 1966, with several modifications over the years (Fig. 2, Fig. 3).⁵⁸ The modified approaches have advantages over the standard Broström repair which are summarised in the Table 1 below.

Fig. 2.

Diagram illustrating Broström lateral ligament repair.

Fig. 3.

Diagram illustrating Broström lateral ligament repair with Gould modification.

Table 1.

Open anatomic repair for chronic lateral ankle instability.

Operative technique	Method	Advantages
Open Broström59,60	Incision over lateral malleolus (or extended longitudinal incision over distal fibula for concomitant tendon/retinaculum repair)	Highly effective and durable.
	ATLF and CFL are identified, the ankle is dorsiflexed and placed into valgus to assess for tears
	Ligaments are dissected from surrounding tissue
	Care must be taken not to damage the sural nerve, branches of the superficial peroneal nerve and peroneal tendons.	Repair ATFL and CFL, retaining anatomic relationship
	Ligament shortening and repair with strong sutures
	After the repair, the ankle should be assessed to confirm that the repair has not limited range of motion.
Gould Modification (Fig. 3)61,62	Broström repair is reinforced by pulling the extensor retinaculum and suturing to distal fibula	Reinforced ATFL repair and stabilises joint by limiting inversion of subtalar joint.
	Extensor retinaculum elevated, peroneal tendon pathology must be excluded
	ATFL±CFL incised from fibula and elevated as a flap
	Anchor inserted into anterior fibula	Increases strength of repair by up to 50%.
	Suture thread through ATFL±CFL
	Repair augmented by attaching posterior edge of extensor retinaculum to the fibula
Karlsson Procedure63	Reduces laxity by sectioning ligament 3–5 mm from insertion point on fibula and excising scar tissue	Advantage over Broström procedure is ligament - bone healing rather than ligament to ligament healing, strengthening the repair and reducing laxity (Initially used for late repair as ATFL and CFL tend to heal with increased length thus increased laxity)
	Ligaments are reattached to fibula using suture anchors

In some cases, internal bracing with suture tape can also be used, with the aim to increase the strength of the reconstruction.64, 65, 66, 67 However, systematic reviews of the current literature demonstrate that clinical and radiographic outcomes are equivalent to the modified Broström repair alone and are comparable in terms of efficacy and safety.^64,65,67,68 Despite this, there may be a role for the use of suture augmentation in lateral ankle ligament repair in highly active individuals or athletes, as one review demonstrated a quicker return to play with suture tape internal bracing when compared to modified Broström procedures alone.⁶⁸

8.1. Clinical outcomes of open modified Broström reconstruction

The open modified Broström repair has shown excellent postoperative outcomes.⁶⁹ In a 26 year follow up post post Broström repair, 85–90% of patients gained ankle stability, with a recovery time of 3–6 months⁷⁰, and 91% of the patients described their ankle function as good or excellent. Further studies demonstrate an overall improvement in AOFAS and VAS scores, with good early functional outcomes and minimal complications.⁷¹ Another systematic review supported the Broström procedure, associating it with a low revision rate (1.2% in a mean 8.4 year follow up period).⁶⁹ General joint laxity is a risk factor for recurrent instability post modified Broström procedure⁷² which is also associated with inferior functional outcomes compared to those without.

9. Arthroscopic lateral ankle ligament repair

9.1. Surgical technique

An alternative to the open Broström method is arthroscopic lateral ankle ligament reconstruction or repair. Arthroscopic repair did not gain popularity when it was initially introduced in 1990's due to higher complexity, higher complications and longer operative times, however with advancing arthroscopy techniques it is now more widely used.^73,74 Arthroscopic techniques using suture anchors were first described by Kushak et al.⁷⁵, and techniques may be all - inside, all - arthroscopic or arthroscopic assisted.

The ankle joint must be arthroscopically examined prior to reconstruction.76, 77, 78 A 2 port approach may be taken in the anteromedial and anterolateral position. Anterior joint line landmarks are identified and the ports are inserted whilst the foot is dorsiflexed. The lateral gutter is cleaned out and the anterior tibio talar joint is explored. In order to visualise the anterior tibiofibular ligament a shaver is used on the lateral side. Landmarks for assessment of the ATFL are the distal insertion of the AITFL on the fibula. This ligament is usually hypertrophied and can be dissected using a shaver. Just distal to the insertion of the AITFL is the expected attachment point of the ATLF on the fibula. The ATLF is then dissected from the capsule and repaired back onto the fibula using a suture anchor under tension. A knotted or knotless technique can be used⁷⁹ (reference vega). The CFL is more challenging to repair directly through this approach and is tensioned indirectly through the ATFL. A Gould modification can be added endoscopically but this technique is less common.⁸⁰ The suture loops may be secured with a knotless anchor or traditional suture anchors may be used.

9.2. Clinical outcomes following arthroscopic lateral ankle ligament repair

Arthroscopic lateral ankle ligament repair is associated with good clinical outcomes. A recent systematic review indicated a significantly improved AOFAS score (22.8–54.2 at a mean follow-up of 17.1 months) and 100% return to sport rate. There was however, an overall complication rate of 11.6%, comparable to that for open techniques.⁸¹ Batista et al. demonstrated that in a cohort of patients undergoing arthroscopic repair none had a recurrence of lateral ankle instability or any recorded complications, with an improvement in mean AOFAS score⁷⁶ over a 25 year period. Further long term studies have indicated improvement in AOFAS, Karlsson score and VAS score.¹⁰³ However there is little literature to evaluate the rate of revision for arthroscopic repair.⁸²

The main complications specifically associated with arthroscopic repair are postoperative nerve injury or suture entrapment^73,79,82,83, but with specialist training and advancement of arthroscopic techniques the incidence of nerve damage can be reduced.⁸⁴

Arthroscopic repair has an advantage over open repair by preserving the soft tissue envelope and improving visualization.⁷⁴ Although open methods have shorter operative time and lower costs⁸⁵, arthroscopic repair may be associated with less post operative pain due to its minimally invasive nature. (Zhi et al., 2020). Despite this, most systematic reviews report similar rates of complication when compared to open repair (see Table 2).

Table 2.

Systematic reviews comparing open and arthroscopic repair of chronic lateral ankle instability.

Study	Inclusion criteria	Number of studies	Cohort size open vs arthroscopic (number of ankles operated on)	Follow up time Open vs arthroscopic (months)	Complications	Functional outcomes
Guelfi et al.87	Open Broströmand modified Broström procedure vs arthroscopic repair	19	505 vs 216	73.3 vs 37.3	Higher rates of surgical complication in arthroscopic repair (15.25% vs 7.92%) Although this did not negatively impact patient satisfaction	Excellent clinical outcomes and patient satisfaction in both open and arthroscopic repair based on AOFOS and Karlsson score
Zhi et al.86	Traditional open or arthroscopic Broström-Gould operations, with one or two suture anchors	9	223 vs 250	28.1 vs 23.8	No statistical difference in rate of postoperative complication (arthroscopic vs open, 10.4% vs10.8%) (RR 0.88, 95% CI: 0.51 to 1.49) No statistical difference in the incidence of nerve associated complications (RR 1.21, 95% CI: 0.53 to 2.75)	AOFOS score significantly higher in short term and for long term follow up for arthroscopic repair Long term follow up in favour of arthroscopic repair, based on VAS and AOFOS score No significant difference regarding stress radiograph outcomes
Brown et al.81	Open vs arthroscopic Broström– Gould technique one or two suture anchors	4	110 vs 97	30.7 vs 19.7	Similar total complication rates, nerve and wound complication rates in 12 month follow up	Improved short term AOFAS and Karlsson functional outcome score with arthroscopic repair, but similar Karlsson function outcome scores in a follow up period of at least 12 months Return to activity rate similar, but within a shorter time period in arthroscopic repair
Moorthy et al.88	Open vs arthroscopic Broström repair	7	158 vs 183	24.7 vs 26.5	No difference in short term complications rate, but significantly lower rate of wound complications with arthroscopic repair overall complication rates (OR = 0.25, 95% CI: 0.07–0.95, p < 0.04)	Higher AOFAS, higher Karlsson score, lower VAS In arthroscopy group No difference in anterior draw test or talar tilt
Attia et al.90	Open vs arthroscopic Broström repair	8	193 vs 214	26.7 vs 23.4	No difference in operative time, complication rate, talar tilt, and anterior drawer tests	Superior AOFAS, VAS score 6–12 months in arthroscopic group Quicker return to weight bearing with arthroscopic repair (14.25 vs 9.0 weeks) (MD = 1.89, CI: 1.24 to 2.54, I2 = 99%, p < 0.001) Similar talar tilt and anterior draw test

Short term follow up is in favour of arthroscopic repair when evaluating clinical functional outcomes^81,86, 87, 88, but there is no difference in radiographic stress testing outcomes.⁸⁹ Most literature suggest similar rates of return to sport (mid to long term recovery), however one study suggests a shorter return to activities in patients undergoing suture tape augmentation^66,86, which may also be dependent on post operative care. Further studies are needed to evaluate long term outcomes.

10. Rehabilitation and return to activities

Post operative rehabilitation is crucial in order to restore a patient's baseline functional status. Conventional management begins with resting the joint in the postoperative period, progressing to mobilisation with support through physiotherapy exercises to strengthen muscles (in particular peroneal muscles) and to improve balance and proprioception.⁹¹ There is also a role for the use of prophylactic ankle bracing to increase joint position sense and lend additional support.⁹¹ Poorer prognosis risk factors include increased age, increased swelling, reduced range of motion, and pain.⁹²

There is however conflicting evidence regarding weight bearing status and post operative physiotherapy protocols96, 97, 98, 99, 100, 101, 102, 103 (Table 3). One systematic review and meta analysis comparing early mobilisation (EM) (within 3 weeks in the postoperative period) and delayed mobilisation (DM) (after 3 weeks post operation) concluded that early mobilisation improves functional outcomes (both AOFOS and Karlsson score), but had higher complication rates, EM vs DM (11.4% vs 3.1% respectively P < 0.001).⁹³ Prolonged immobilisation in general, is not recommended⁹⁴, as this may limit joint mobility, but weight bearing should be relatively delayed.⁹⁵

Table 3.

Rehabilitation protocols post surgical intervention for chronic lateral instability.

Study	Surgery	Immobilisation (post operative period)	Weight bearing status (post operative period)	Physiotherapy	Return to play
Baraza et al. (2017)96	Open modified Broström - Gould Procedure	Cast 6 weeks	Non weight bearing for 6 weeks, then weight bearing as tolerated in malleoloc splint	Gentle range of motion with physiotherapy	Not stated
Myamoto et al.97	Gracilis autograft reconstruction	Group I - short leg cast for 4 weeks, then soft ankle orthosis for another 4 weeks Group A - soft ankle orthosis immediately post surgery Both groups - soft ankle orthosis removed after 8 weeks	Group I - weight bearing at 2 weeks, full weight bearing at 4 weeks Group A - weight bearing as tolerated immediately post surgery	Group I - ROM and muscle training 4 weeks post op Group A - ROM and muscle training 2 days post surgery	Similar functional outcome, significant radiographic improvement in both groups. Return to full athletic activity in Group A than Group I (13.4 vs 18.5 week, P < 0.01)
Matsui et al.100	All inside Broström Gould (open/arthroscopic repair)	Not specified	Weight bearing permitted day of surgery	Physiotherapy initiated day of surgery	Mean Return to activity 16.5 vs 17.1 weeks (arthroscopic vs open repair)
Jiang et al.102	Arthroscopic anatomic repair for patients with CAI and patients with CAI and OCL (Osteochondral lesion) post anatomic repair	Splint for 2 weeks	Group A (patients with OCL and CLAI) Full weight bearing 8 weeks post op Group B (Isolated CLAI) Full weight bearing 4 weeks post op	Group A (patients with OCL) - Joint motion exercises 2 weeks post op Group B (Isolated CLAI) - Joint motion exercises 3 weeks post op	Good to excellent function results in 90% (AOFOS, VAS and Tegner score) No significant difference was found in VAS, AOFAS, or Tegner scores between between group A and B Restricted ROM group A higher than group B (23.5vs 5.6% P = 0.043)
Acevedo and Mangone (2015)103	Arthroscopic Broström procedure	−2 weeks short leg splint -2-4 week boot walker - 4–6 weeks active lace up ankle brace - 12 weeks active ankle brace	Non weight bearing 2 weeks post op 2–4 weeks weight bearing as tolerated 4–6 weeks full weight bearing	2–6 weeks gentle range of motion - after 6 weeks proprioception exercises	Functional test performance equivalent of 90% of unaffected leg Restoration of normal ankle strength and stability

10.1. Biomechanics post surgery for CAI

Surgical intervention aims to restore biomechanic of the ankle joint. Regardless of operative method, surgical intervention has shown to reduce preoperative talar tilt and anterior talar translation, comparable to the contralateral ankle, however 10.5% of patients have a decreased range of motion in the ankle post surgery.¹⁰⁴ Generalised ligamentous laxity, high preoperative talar tilt angle (>15°), and high preoperative anterior displacement of the talus (>10 mm) may also be associated with greater risk of clinical failure.¹⁰⁵

Non-anatomic methods alter biomechanics within the ankle, and subtalar joint, leading to abnormal plantar loading.106, 107, 108 Cadaveric models have demonstrated that even though ankle laxity is reduced with surgical repair, joint motion is restricted after Watson Jones procedure when compared to the intact ankle, which is not the case in anatomic repair.¹⁰⁹ Clinical observations confirm that Watson-Jones ankle procedure does not restore hindfoot kinematics, in particular the subtalar joint.^108,109 In addition, Rosenbam et al. demonstrated disturbed ankle joint kinetics with the Evans Jones procedure.^106,107

10.2. Dynamic training

Dynamic training may be useful in regaining functional ability, balance and postural control. Dynamic balance training has been effective in the treatment of patients with CAI and early dynamic training post acute lateral ankle instability has shown to reduce time to return to sport, and is associated with increased functional performance.¹¹⁰ However there are few studies evaluating its role specifically in post operative rehabilitation.¹¹¹

10.3. Return to sports

Current literature lacks consistency when evaluating return to sport timelines and there is a lack of formal criteria to aid this decision.¹¹² Studies indicate an average return to play time of 4.1–4.7 month post lateral ligament repair.¹¹³)¹¹² There is evidence to suggest that greater injury grade and functional limitation is a prognostic factor for longer disability duration.⁹²

10.4. The impact of biological sex on clinical outcomes following surgery for CAI

When considering sex specific outcomes following lateral ankle ligament repair no differences have been reported in AOFAS, Karlsson scores and success rates between males and females.¹¹⁴

10.5. The impact of smoking on surgery for CAI

Smoking cessation should be encouraged prior to surgery. Lee et al. concluded that wound complications are more common in smokers post anatomical reconstruction, although clinical and radiographic outcomes are not affected.¹¹⁵ There is however little further evidence to evaluate the impact of smoking post CAI repair.

10.6. Complications following surgical reconstruction for CAI

Although complications associated with surgical repair are infrequent, they pose certain challenges, such as nerve injuries, local wound problems and recurrent instability. Wound complications are a common complication (2.7%) and are mostly superficial.¹¹⁶ Nerve dysfunction may also occur, which may be experienced as self resolving paraesthesia, or a neuroma, requiring excision. It is a recognised complication of arthroscopic repair, but it may also occur during open repair, with the sural nerve and superficial peroneal nerve being at greatest risk of damage. Sammarco et al. reported an overall incidence of postoperative nerve injury of 6.2%, with a higher prevalence amongst patients undergoing non-anatomic repair.¹¹⁶

Recurrent instability has been reported with all types of surgical repair, but subjective instability is more associated with non-anatomic methods than with anatomic methods.¹¹⁶ Physiotherapy is recommended to treat subjective failure, however failing conservative treatment some cases of recurrent instability may need revision surgery. Stiffness is also a common complication post reconstruction, but is more tolerable. Early motion after surgery is important to avoid this. Overtightening of the graft in non-anatomic surgical procedures may also lead to continuing pain and stiffness.^117,118

Newer techniques for the treatment of CAI are still being developed. This includes investigation into arthroscopic anatomy reconstruction or potentially a role for the future use of synthetic scaffold support, or even the use nanoscaffold using electrospinning technology. However further research is needed to implement its practice.^119,120

In order to improve applicability, a standardised post operative protocol is required, with a consensus weight bearing status and return to sport.¹¹² Higher quality studies are needed to evaluate post operative protocols as meta-analyses have demonstrated significant heterogeneity within the current literature.⁹³ There is also a need for the use of validated patient reported outcomes. The consequence of inadequate PROM usage and inconsistency in the evaluation of CAI may mean that, on a national level, money is spent on suboptimal treatment strategies.¹²¹

11. Conclusion

Surgical repair has proven to show excellent outcomes for patients suffering from chronic ankle instability, however larger prospective studies should be carried out to evaluate the use of newer surgical techniques. Standardised validated PROMS and evidence-based protocols in the rehabilitation periods are crucial for positive and reproducible outcomes, in addition to addressing all contributing co-pathologies.

Funding/sponsorship

There was no funding/sponsorship to support this study.

Informed consent (patient/guardian), mandatory only for case reports/clinical images

Not applicable.

Institutional ethical committee approval (for all human studies)

Not applicable.

Authors contribution

S Dias: Writing - Original Draft, Methodology, Formal analysis, Investigation, Data Curation, Writing - Review & Editing.

T Lewis: Conceptualization, Methodology, Formal analysis, Investigation, Data Curation, Writing - Original Draft, Writing - Review & Editing, Supervision, Project administration.

Y Alkhalfan: Investigation, Resources, Writing - Original Draft, Visualization.

R Ahluwalia: Conceptualization, Methodology, Writing - Review & Editing, Supervision, Project administration.

R Ray: Writing - Original Draft, Conceptualization, Methodology, Writing - Review & Editing, Supervision, Project administration.

Declaration of competing interest

None of the authors have any conflicts of interest to declare.