Ligament Repair and Augmentation for Chronic Ankle Instability

Most people gradually recover after a routine ankle sprain if it is treated and rehabilitated properly. Some patients, however, still feel that the ankle “gives way” months later, lose control on uneven ground, or repeatedly sprain the ankle while running, stopping, changing direction, or landing from a jump. This pattern may have developed into chronic ankle instability.

The lateral ankle is stabilized mainly by the anterior talofibular ligament, calcaneofibular ligament, and posterior talofibular ligament. The anterior talofibular ligament sits more anteriorly, is relatively thin, and is the structure most easily injured during an inversion sprain.

The anterior talofibular ligament limits excessive forward translation of the talus, while the calcaneofibular ligament contributes more to limiting excessive hindfoot inversion. If a torn ligament heals in an overly lax state, the ankle may repeatedly move abnormally.

Chronic ankle instability also involves proprioception, muscle reaction speed, and balance control. After sensory receptors in the ligament are injured, the patient may no longer sense ankle position as quickly as before; stabilizing muscles such as the peroneals and tibialis anterior may also show weakness or delayed activation.

This is why some patients have ligament injury that does not look severe on imaging, yet clearly feel that the ankle is “not under control.”

Typical symptoms are recurrent sprains and a feeling of instability, such as:

Assessment usually combines the anterior drawer test, talar tilt test, MRI, and functional scales. CAIT, FAAM, and Karlsson scores can evaluate instability sensation, daily activity, and sport ability.

The Y-Balance Test, Star Excursion Balance Test, and single-leg stance can further assess dynamic stability. When available, three-dimensional gait analysis can record joint motion, ground reaction forces, and muscle activation changes.

The 2021 Chinese clinical practice guideline recommends proprioceptive and neuromuscular training for chronic ankle instability to improve dynamic postural stability and subjective stability during movement. Bracing or taping may be used as support, but they should not be the only long-term treatment.

Common training includes ankle muscle strengthening, single-leg balance, dynamic balance, jump-landing control, and proprioceptive training.

In a Chinese series of 66 patients who completed 6 weeks of rehabilitation, patients who added unconscious proprioceptive training improved more in walking speed, cadence, and balance tests. In another 30-patient series, adding 4 weeks of dynamic destabilization training to usual rehabilitation improved dynamic balance and muscle activation before and after landing.

Surgery is usually evaluated only when recurrent sprains, obvious functional instability, or mechanical instability persist after about 3 to 6 months of structured nonoperative treatment. International expert consensus also considers persistent instability after 3 to 6 months of nonoperative care an important condition for considering surgery.

When the anterior talofibular ligament remnant has good tissue quality and enough ligament remains for suturing and tightening, anatomic repair is a common surgical option.

The basic idea of the Broström and modified Broström procedures is to suture the stretched or torn lateral ligament back near its original attachment to restore tension. Some techniques also reinforce the repair with nearby supporting tissue.

More procedures can now be performed arthroscopically, with smaller incisions and the ability to inspect the joint for synovitis, cartilage injury, or impingement.

Anatomic repair remains an important treatment for most primary chronic lateral ankle instability. In patients with good ligament tissue, direct repair can usually avoid tendon harvest and large bone tunnels.

Some patients still have repairable ligament tissue, but the surgeon may worry that the injured tissue alone lacks early strength, especially in young patients, high-demand athletes, or people hoping to resume training earlier. In this setting, a high-strength suture tape can be added to the ligament repair, creating an auxiliary structure similar to an internal brace.

It can be understood as mechanical protection beside the repaired ligament. During early rehabilitation, the augmentation material helps limit excessive anterior translation and inversion, reducing abnormal load on the healing tissue.

In 55 patients aged 18 to 29 years who underwent all-arthroscopic anterior talofibular ligament augmentation and footprint reconstruction, the AOFAS score improved from 58.76 preoperatively to 75.35 at 3 months, the Karlsson score improved from 56.54 to 77.15, and pain VAS decreased from 6.29 to 1.35. Patients returned to a certain sport level after about 4.5 months on average, but mean follow-up was only 5.3 months, so these mainly reflect early outcomes.

A 2026 meta-analysis including 13 comparative datasets and 1015 patients found that, compared with modified Broström-Gould repair alone, Internal Brace augmentation showed some advantage in sport-specific functional scores. Limited data also suggested return to sport may be 4 to 8 weeks earlier. Overall complications, recurrence, and most functional outcomes did not show clear differences between the two methods.

After many years of recurrent sprains, the anterior talofibular ligament may become very thin, severely scarred, or almost absent as a reliable remnant for suturing. Tightening and suturing such poor tissue may increase the risk of recurrent laxity or failure.

In some arthroscopic findings, the anterior talofibular ligament remnant has formed a hard scar with the lateral joint capsule; after separation, the remaining ligament is too thin for reliable repair.

Ligament reconstruction can then be considered. Autograft tendon, allograft tendon, or artificial material is used to recreate a stabilizing structure close to the course of the anterior talofibular ligament and, when necessary, the calcaneofibular ligament. Common reconstruction considerations include poor remnant quality, generalized ligament laxity, failed prior repair, and some high-BMI patients.

A study of 116 high-intensity sports participants compared arthroscopic modified reconstruction with LARS artificial ligament reconstruction. At 6 months, AOFAS, Karlsson, Tegner, and pain scores improved in both groups, with similar short-term outcomes; the modified method used smaller anchors to reduce bone damage.

Another group of 23 patients aged 18 to 34 years with near loss of anterior talofibular ligament function and difficult repair underwent artificial ligament reconstruction. At 3 months, AOFAS improved from 49.95 to 76.13 and pain VAS decreased from 3.13 to 1.69. Average follow-up was only 7.4 months, so longer observation is still needed for artificial material, bone tunnels, and long-term stability.

Many cases of chronic ankle instability are mainly anterior talofibular ligament injuries, and isolated repair or reconstruction can restore stability. If the calcaneofibular ligament is also clearly torn and hindfoot inversion stability is affected, treating only the anterior talofibular ligament may be insufficient.

A 60-year-old patient with long-term recurrent sprains had anterior talofibular ligament and calcaneofibular ligament rupture, ankle impingement, and obvious osteoarthritis. After all-arthroscopic combined reconstruction of both ligaments, the Kofoed score improved from 51 before surgery to 94 at 8 weeks.

Some patients also have deltoid ligament injury, and the ankle may then be unstable in rotation as well.

A gait analysis study of 33 patients with chronic ankle instability found that patients with deltoid ligament injury had significantly worse axial rotational stability. This suggests that long-term recurrent sprain should not be evaluated only through the anterior talofibular and calcaneofibular ligaments.

If MRI shows disorganization, discontinuity, or abnormal attachment-site signal of the deltoid ligament, the finding should be interpreted together with physical examination.

This also helps explain why some patients still feel the ankle is unstable during rotation after lateral ligament surgery: the instability may involve multiple directions and structures.

Protection time varies greatly between procedures.

For some isolated anterior talofibular ligament augmentation protocols, ankle pump and range-of-motion exercises start early; some patients can bear weight earlier, begin proprioception and balance training in week 2, and then gradually increase strength and sport training.

If tendon graft reconstruction or combined anterior talofibular and calcaneofibular ligament reconstruction is performed, protection is usually longer.

A larger systematic review included 720 patients who underwent tendon-graft reconstruction. About 95.3% eventually returned to some sport activity, 84.3% returned to the preinjury sport level, and average return-to-sport time was about 17 weeks. The actual timeline still depends on the procedure, cartilage status, strength, balance ability, and sport type.

Surgery can restore mechanical stability, but it cannot automatically correct long-standing neuromuscular control problems. Patients with chronic ankle instability may also have delayed peroneal reaction, weakness, abnormal dynamic balance, and excessive dependence on vision.

Rehabilitation should therefore gradually include single-leg standing, perturbation training, Y-balance or star-excursion drills, jump-landing training, and sport-specific training. Return to basketball, football, badminton, and other sports involving stopping, cutting, and jumping should consider stability sensation, range of motion, strength, dynamic balance, and movement control.

If the anterior talofibular ligament remnant has good quality, anatomic repair is usually preferred.

If repair is possible but the patient has high sport demand or the surgeon wants extra early mechanical protection, repair combined with Internal Brace or another augmentation technique may be considered.

If the original ligament is severely scarred, the remnant is insufficient, generalized laxity is present, or a previous repair has failed, tendon or other-material reconstruction is more likely to be appropriate.

Treatment planning should also consider the calcaneofibular ligament, deltoid ligament, ankle cartilage, talar osteochondral lesions, lower-limb alignment, and the patient’s future sport goals.