Clinical association of acute lateral ankle sprain with syndesmotic involvement: a stress radiography and magnetic resonance imaging study

BACKGROUND: Information concerning the clinical association between syndesmosis injury and grade of lateral ankle ligament damage would aid in the diagnosis and treatment of ankle sprains. HYPOTHESIS: Evaluation of lateral ligament injury in terms of percentage tear of both the anterior talofibular and calcaneofibular ligaments can provide information on the extent of syndesmotic involvement. STUDY DESIGN: Prospective cohort study. METHODS: Twenty-five patients volunteered to have magnetic resonance imaging examinations performed and 21 volunteered to undergo graded stress radiographs. Talar tilt angles were measured from radiographs taken with 0, 6, 9, 12, and 15 daN of force applied medially just above the ankle joint, and the percentage of ligament tear and grade of injury were determined. Scans were obtained with the foot in neutral and plantar flexion to image the anterior talofibular and calcaneofibular ligaments. RESULTS: Grades of lateral ligament injury determined by magnetic resonance imaging and graded stress radiography were the same. The extent of syndesmotic injury could be assessed for all patients. CONCLUSIONS: Intact tibiofibular ligaments were found equally frequently among patients with normal or any grade of lateral ligament damage, but the more severe injuries to the syndesmotic ligaments were associated with normal or minimally traumatized lateral ligaments. The inverse correlation can be explained on the basis of the difference between the mechanisms that precipitate these injuries.     

Collateral ligaments of the ankle: high-resolution MR imaging with a local gradient coil and anatomic correlation in cadavers.

Findings at high-resolution magnetic resonance (MR) imaging of the lateral and medial collateral ligaments of the ankle were compared with findings in anatomic sections from cadavers. MR imaging of six cadaveric feet was performed with a newly developed local gradient coil and axial and coronal T1-weighted spin-echo sequences. Axial imaging provided optimum views of the anterior and posterior talofibular ligaments, the deep layers of the medial collateral ligament, and the tibionavicular ligament. Coronal imaging allowed complete visualization of the calcaneofibular, posterior talofibular, tibiocalcaneal, and posterior tibiotalar ligaments. In both imaging planes, differentiation of the deep and superficial layers of the medial collateral ligament was possible. Differentiation between the syndesmotic complex and the lateral collateral ligament was accomplished easily; in particular, differentiation of the posterior tibiofibular ligament from the posterior talofibular ligament was not difficult because of the differing insertions of these ligaments. The inhomogeneous appearance of the medial collateral ligament and the posterior talofibular ligament on MR images correlated with areas of fatty tissue on corresponding microscopic sections. High-resolution MR imaging with a newly developed local gradient coil allows excellent visualization of the lateral and medial collateral ligaments of the ankle.     

运动员及演员踝外侧韧带断裂

文章介绍了踝外侧韧带断裂的检查方法,对距腓前与跟腓韧带全断裂者需手术治疗,术后能恢复训练。     

A biomechanical study of human lateral ankle ligaments and autogenous reconstructive grafts

The purpose of this study was to investigate the biomechanical behavior of human anterior talofibular and calcaneofibular ligaments, as well as peroneus brevis, split peroneus brevis, and toe extensor tendon grafts. This article represents the first published data comparing the most frequently injured ankle ligaments to the most commonly used autogenous reconstructive grafts. Twenty fresh human ankles provided the bone-ligament-bone and tendon graft specimens for biomechanical testing on a Minneapolis Testing System. Protocol consisted of cyclic loading at physiologic deflections, followed by several load-deflection tests at varying velocities, followed by a final extremely rapid load to failure test. The load-deflection data for all ligaments and tendons demonstrated nonlinearity and strain rate dependence. The maximum load to failure for the anterior talofibular ligament was the lowest of all specimens tested, while its strain to failure was the highest. The loads to failure of the peroneus brevis and split peroneus tendons were significantly greater than the anterior talofibular ligament and approximately equal to the calcaneofibular ligament. Strains to failure for all tendons were significantly less than ligament strains. The high strain to failure of the anterior talofibular ligament demonstrates its physiologic function of allowing increased ankle plantar flexion-internal rotation, while its low load to failure shows its propensity for injury. The greater strength of the tendon grafts explains the success of most reconstructive procedures in reestablishing stability in chronic ankle sprains; at the same time, the data presented suggest that those surgical procedures sacrificing the entire peroneus brevis tendon are unnecessary.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of an ankle brace on the 3-dimensional kinematics and tibio-talar contact condition for lateral ankle sprains

Ten fresh-frozen cadaveric ankles were studied to investigate the effect of an ankle brace (Air-Stirrup) on the three-dimensional (3-D) motion and contact-pressure distribution of the talo-tibial joint with lateral ligamentous injury. Three-dimensional motion and contact-pressure distribution were simultaneously measured under dynamic conditions employing a direct linear-transformation technique and a dynamic-pressure sensor, respectively. Inversion increased significantly upon severing of the anterior talo-fibular (ATF) ligament and calcaneo-fibular (CF) ligaments; however, restoration to the intact level was observed following application of the ankle brace. Internal rotation also increased upon severing of the lateral ligaments in the plantar flexion; however, this difference was not altered by using the ankle brace. The contact area on the articular surface of the talus shifted from posterior to anterior between plantar flexion and dorsal flexion; additionally, a high pressure area was evident in the medial aspect of the talus following severing of the lateral ligaments. Upon application of the ankle brace, however, no significant changes were apparent in the contact condition. The results of this study suggest that stabilization against inversion is the major function of braces in terms of protection of ankle sprains. Ankle sprains, however, often occur in combinations of inversion, plantar flexion and internal rotation; therefore, restriction of plantar flexion and internal rotation may also be an important function of the ankle brace.     

Surgical treatment of lateral ankle instability syndrome

Lateral ankle instability syndrome is defined by pain and instability caused by ligament laxity. Anterior talofibular ligament laxity, with or without calcaneofibular laxity and other abnormalities, is often present in conjunction with peroneus brevis tendon tears, abnormal ligament placement, tibialis posterior tendon tears, osteochondritis dissecans, arthritis, synovitis, loose bodies, and tarsal coalition. Surgical reconstructions were performed on 43 ankles using a split peroneus brevis tendon graft routed through osseous tunnels in the talus, fibula, and calcaneus and resutured to the reconstructed anterior talofibular and calcaneofibular ligaments. The tunnel locations, transfer routes, and tendon reinforcement were modifications based on the Elmslie procedure. Good and excellent results were achieved in 91% of the patients. Ninety-eight percent of the patients achieved stability. Followup was from 9 months to 11 years. Twenty-one patients had preoperative and intraoperative findings that required additional procedures. Thorough evaluation of patients with lateral ankle instability syndrome increases the frequency of finding associated abnormalities, which if left uncorrected, may adversely affect the outcome of surgery.     

Treatment of acute lateral ankle ligament rupture in the athlete. Conservative versus surgical treatment

Acute lateral ankle ligament sprains are common in young athletes (15 to 35 years of age). Diagnostic and treatment protocols vary. Therapies range from cast immobilisation or acute surgical repair to functional rehabilitation. The lateral ligament complex includes 3 capsular ligaments: the anterior tibiofibular (ATFL), calcaneofibular (CFL) and posterior talofibular (PTFL) ligaments. Injuries typically occur during plantar flexion and inversion; the ATFL is most commonly torn. The CFL and the PTFL can also be injured and, after severe inversion, subtalar joint ligaments are also affected. Commonly, an athlete with a lateral ankle ligament sprain reports having 'rolled over' the outside of their ankle. The entire ankle and foot must be examined to ensure there are no other injuries. Clinical stability tests for ligamentous disruption include the anterior drawer test of ATFL function and inversion tilt test of both ATFL and CFL function. Radiographs may rule out treatable fractures in severe injuries or when pain or tenderness are not associated with lateral ligaments. Stress radiographs do not affect treatment. Ankle sprains are classified from grades I to III (mild, moderate or severe). Grade I and II injuries recover quickly with nonoperative management. A non-operative 'functional treatment' programme includes immediate use of RICE (rest, ice, compression, elevation), a short period of immobilisation and protection with a tape or bandage, and early range of motion, weight-bearing and neuromuscular training exercises. Proprioceptive training on a tilt board after 3 to 4 weeks helps improve balance and neuromuscular control of the ankle. Treatment for grade III injuries is more controversial. A comprehensive literature evaluation and meta-analysis showed that early functional treatment provided the fastest recovery of ankle mobility and earliest return to work and physical activity without affecting late mechanical stability. Functional treatment was complication-free, whereas surgery had serious, though infrequent, complications. Functional treatment produced no more sequelae than casting with or without surgical repair. Secondary surgical repair, even years after an injury, has results comparable to those of primary repair, so even competitive athletes can receive initial conservative treatment. Sequelae of lateral ligament injuries are common. After conservative or surgical treatment, 10 to 30% of patients have chronic symptoms, including persistent synovitis or tendinitis, ankle stiffness, swelling, pain, muscle weakness and 'giving-way'. Well-designed physical therapy programmes usually reduce instability. For individuals with chronic instability refractory to conservative measures, surgery may be needed. Subtalar instability should be carefully evaluated when considering surgery.     

Injuries of the lateral collateral ligaments of the ankle: assessment with MR imaging

The aim of this study was to evaluate the ability of MRI to display injuries of the lateral collateral ligamentous complex in patients with an acute ankle distorsion trauma. The MR examinations of 36 patients with ankle pain after ankle distorsion were evaluated retrospectively without knowledge of clinical history, outcome and/or operative findings. The examinations were performed on a 1.5-T whole-body imager using a flexible surface coil. The signs for ligamentous abnormality were as follows: complete or partial discontinuity, increased signal within, and irregularity and waviness of the ligament. The results were compared with operative findings in 18 patients with subsequent surgical repair. Eighteen patients with conservative therapy had a follow-up MR examination after 3 months. There was 1 sprain, 3 partial and 32 complete tears of the anterior talofibular ligament, and 5 sprains, 5 partial, and 7 complete tears of the calcaneofibular ligament. There were no lesions of the posterior talofibular ligament. Compared with surgery, MRI demonstrated in 18 of 18 cases the exact extent of anterior talofibular ligament injuries and underestimated the extent in 2 of 8 cases of calcaneofibular ligament injury. In patients with follow-up MRI after conservative therapy, a thickened band-like structure was found along the course of the injured ligament in 17 of 18 cases. The absence of ligament repair after conservative treatment was confirmed during operative revision in one case. The MRI technique allows for grading of the extent of injury of the lateral collateral ligamentous complex after acute ankle strain. It seems to be suitable for monitoring the healing process after conservative-functional treatment of ligament tears. Received: 29 June 1998; Revision received: 21 October 1998; Accepted: 22 October 1998     

Injuries of the lateral ankle ligaments: classification with tenography and arthrography

To assess the value of tenography of the peroneal tendon sheaths and of arthrography of the tibiotalar joint for the diagnosis and classification of recent ruptures of the lateral ankle ligaments, the authors performed a prospective study on 108 patients with inversion trauma of the ankle. All patients underwent tenography. Arthrography was performed if results of tenography were negative. All patients with positive tenographic or arthrographic results underwent surgery. Tenography proved to be reliable in the diagnosis of injuries of the calcaneofibular ligament (sensitivity, 88%; specificity, 87%-94%). The positive predictive value of tenography in combination with arthrography was 100% for the diagnosis of lateral ligament ruptures. The authors conclude that a combination of arthrography and tenography is a reliable method for diagnosing recent ruptures of the lateral ankle ligaments and for differentiating between isolated ruptures of the talofibular ligament and combined lesions of both the talofibular and the calcaneofibular ligaments.     

正常踝外侧副韧带的解剖及MRI观察对比研究

目的解剖观察踝关节外侧各韧带的形态特点,并与低场MR扫描测量数据进行对比,为临床提高MR诊断踝关节韧带损伤提供依据。方法将10例正常成人尸体足踝关节标本（每例取一侧）进行解剖观察并测量踝外侧各韧带的长、宽、厚度值,与自然位（跖屈约20。）MR扫描测量结果进行统计学分析。结果自然位MR检查能较好地显示各韧带的解剖形态,MR测量距腓前韧带（ATFL）及跟腓韧带（CFL）的平均长度分别为（14．190±0．595）mm和（23．46±1．578）mm,宽度（8．76±0．883）mm和（5．700±0．442）mm,厚度（1．840±0．190）mm和（2．110±0．296）mm。解剖测量距腓前韧带及跟腓韧带的平均长度分别为（14．128±0．610）mm和（23．452±1．506）mm,宽度（8．782±0．916）mm和（5．704±0．453）mm,厚度（1．882±0．224）mm和（2．106±0．313）mm,解剖和MR各测量值间差异无统计学意义（P〉0．05）。结论自然位是MR检查踝关节韧带损伤的较理想体位,解剖与MR测量值基本一致,低场MRI能较准确显示踝外侧副韧带的形态。     

The course of the superficial peroneal nerve in relation to the ankle position: anatomical study with ankle arthroscopic implications

Despite the fact that the superficial peroneal nerve is the only nerve in the human body that can be made visible; iatrogenic damage to this nerve is the most frequently reported complication in anterior ankle arthroscopy. One of the methods to visualize the nerve is combined ankle plantar flexion and inversion. In the majority of cases, the superficial peroneal nerve can be made visible. The portals for anterior ankle arthroscopy are however created with the ankle in the neutral or slightly dorsiflexed position and not in combined plantar flexion and inversion. The purpose of this study was to undertake an anatomical study to the course of the superficial peroneal nerve in different positions of the foot and ankle. We hypothesize that the anatomical localization of the superficial peroneal nerve changes with different foot and ankle positions. In ten fresh frozen ankle specimens, a window, only affecting the skin, was made at the level of the anterolateral portal for anterior ankle arthroscopy in order to directly visualize the superficial peroneal nerve, or if divided, its terminal branches. Nerve movement was assessed from combined 10° plantar flexion and inversion to 5° dorsiflexion, standardized by the Telos stress device. Also for the 4th toe flexion, flexion of all the toes and for skin tensioning possible nerve movement was determined. The mean superficial peroneal nerve movement was 2.4 mm to the lateral side when the ankle was moved from 10° plantar flexion and inversion to the neutral ankle position and 3.6 mm to the lateral side from 10° plantar flexion and inversion to 5° dorsiflexion. Both displacements were significant (P < 0.01). The nerve consistently moves lateral when the ankle is manoeuvred from combined plantar flexion and inversion to the neutral or dorsiflexed position. If visible, it is therefore advised to create the anterolateral portal medial from the preoperative marking, in order to prevent iatrogenic damage to the superficial peroneal nerve.     

MR imaging of the most commonly injured ankle ligaments. Part I. Normal anatomy.

To determine the optimum foot position and imaging plane at magnetic resonance (MR) imaging of each ankle ligament, 10 cadaver ankles were dissected to visualize the orientation, precise attachment sites, and relationships of each ligament. Then eight cadaver ankles were studied with MR imaging and were cryosectioned in the optimum imaging planes. The ankles of 12 healthy volunteers were imaged to ensure consistency in identifying the normal ligaments. With the foot taped into full dorsiflexion of 10 degrees-20 degrees, axial imaging provided optimum views of the anterior, posterior, and inferior tibiofibular ligaments and of the anterior and posterior fibulotalar ligaments and provided an overview of the deltoid ligament. Coronal images provided full-length views of the tibiospring, tibiocalcaneal, and posterior tibiotalar parts of the deltoid ligament. With the foot taped into full plantar flexion of 40 degrees-50 degrees, axial imaging optimized visualization of the fibulocalcaneal ligament and of the tibionavicular and anterior tibiotalar parts of the deltoid ligament. Sagittal images provided the best full-length views of the spring ligament.     

The role of the peroneal tendons in passive stabilisation of the ankle joint: an in vitro study

Purpose

Peroneal tendons are known as active stabilizer in acute ankle sprain while an intact ankle mortise and intact lateral ligaments are required for passive stability of the ankle joint. The goal of this study is to determine the peroneal tendons as passive stabilizer in case of lateral ligament instability.

Methods

Twelve (12) human lower leg cadaver specimens underwent a torsion simulation in the testing system, 858 Mini Bionix^® (MTS^® Systems Corporation, Eden Prairie, MN, USA) and a specially designed mounting platform for the specimens. The preset torsion between tibia and calcaneus was primarily set at 30° of internal rotation during plantar flexion and hindfoot inversion. The resisting torque around mechanical tibial axis was recorded which ensures stability in ankle sprain trauma. The first series of measurements were performed on healthy specimens and the following after transecting structures in following order: ATFL (anterior talofibular ligament) in combination with CFL (calcaneofibular ligament), followed by peroneus longus tendon and finally peroneus brevis tendon.

Results

The combined lateral ATFL and CFL instability shows a decrease of the resisting torque which ensures stability in ankle sprain trauma. Only a transection of PLT with existing lateral dual-ligament instability results in a significant decrease in torque (p < 0.0001).

Conclusion

The PLT has a substantial effect on passive stability at a present lateral ligament lesion in ankle sprain trauma. A deficiency in viscoelastic properties of the peroneus longus tendon must be considered in diagnostic and treatment for ankle instability.     

Stability of the loaded ankle. Relation between articular restraint and primary and secondary static restraints

The stabilizing capacity of the ligaments and articular surface in the ankle was determined under defined physiologic loading conditions. The concept of primary and secondary constraints was adapted to the ankle. With physiologic loading, the articular surface accounted for 30% and 100% of stability in rotation and version, respectively. That the articular surface was the sole source of inversion and eversion stability under the prescribed physiologic loading conditions has not been previously reported. The demonstration that the articular surface resists inversion displacement in the loaded ankle supports the conclusion of previous studies that rotation, rather than inversion, may account for a type of clinically symptomatic ankle instability. Further, ankle instability may occur during loading and unloading but not once the ankle is fully loaded. The results of our study confirm the importance of the anterior talofibular and calcaneofibular ligaments and suggest an important role for the deltoid ligament.     

Examination of the sprained ankle: anterior drawer test or arthrography?

The accuracy of the anterior drawer test for the diagnosis of recent lateral ligament tears in the ankle was evaluated in a series of 192 patients using surgical or arthrographic findings for reference. Considerable overlapping of results was obtained in ankles with and without ligament tear. Twenty-eight per cent of the anterior talofibular ligament tears, and 38% of the combined anterior talofibular and calcaneofibular tears were not detected, and single and combined tears could not be differentiated. It is concluded that the anterior drawer test is too unreliable as a basis for any decision regarding surgical treatment of a recent sprain. Therefore, arthrography is recommended as the method of choice in such cases of recent ankle sprain, where the need of surgery has to be supported by X-ray analysis.     

Anatomie und Kinematik der Sprunggelenke des Menschen

In the ankle (talocrural) joint, the lower end of the tibia and fibula embrace the trochlea tali. Thus, an approximately uniaxial joint is formed which permits dorsiflexion and plantarflexion of the foot against the leg. Due to the geometry of the trochlea tali, conjunct lateral rotation of the fibula against the tibia occurs at the tibiofibular articulations synchronously with active dorsiflexion at the ankle joint. Movements at the talocrural joints are mainly limited by the opposing muscles as well as by strong collateral ligaments. Talus and calcaneus form a functional unit connected by posterior and anterior articulations. The posterior articulation is the subtalar (talocalcaneal) joint; in the anterior articulation, talar facets of the calcaneus together with the posterior surface of the navicular and the superior fibrocartilaginous surface of the plantar calcaneonavicular ligament form a concavity for the talar head. Thus, the talocalcaneonavicular joint is a compound and--like the subtalar joint--a multiaxial articulation. On the weight-bearing foot, the distal tarsus and metatarsus are pronated and supinated against the talus in order to maintain plantigrade contact. When the foot is off the ground, these movements are modified to eversion and inversion, also involving the calcaneocuboid joint. In addition, movements between the calcaneus and cuboid also occur during pronative or supinative changes between the fore- and hindfoot. Limitation of movements is due to leg muscles as well as strong ligaments. Finally, the cuneonavicular, cuboideonavicular, intercuneiform and cuneocuboid joints permit some additional alterations of the loaded foot in contact with the ground.     

Anatomical reconstruction of the lateral ligaments of the ankle with a gracilis autograft: a new technique using an interference fit anchoring system

BACKGROUND: Few anatomical and minor invasive procedures have been reported for surgical reconstruction of the lateral ligaments to treat lateral instability of the ankle. Furthermore, there are no standards according to which ligaments should be reconstructed. HYPOTHESIS: A new technique for anatomically reconstructing the lateral ligaments of the ankle using an interference fit anchoring system and determining which ligaments need to be reconstructed according to the results of standard stress radiography of the talocrural and subtalar joints will be effective for treating lateral instability of the ankle. STUDY DESIGN: Case series; level of evidence, 4. METHODS: Twenty-one patients with lateral instability of the ankle underwent surgery using the proposed interference fit anchoring system. Standard stress radiographs of the subtalar joint were performed, and if the talocalcaneal angle was less than 10 degrees , only the anterior talofibular ligament was reconstructed; if there was a 10 degrees or greater opening of the talocalcaneal angle, both the anterior talofibular ligament and the calcaneofibular ligament were reconstructed. RESULTS: In the 17 patients who received only the anterior talofibular ligament reconstruction, the mean talar tilt angle on standard stress radiography of the talocrural joint was 14.5 degrees +/- 1.7 degrees before surgery and 2.6 degrees +/- 0.8 degrees 2 years after surgery (P < .0001). For the 4 patients who had both the anterior talofibular ligament and calcaneofibular ligament reconstructed, the mean talar tilt angle was 16.5 degrees +/- 1.5 degrees before surgery and 3.0 degrees +/- 0.5 degrees 2 years after surgery (P = .0015). The overall mean talocalcaneal angle on standard stress radiography of the subtalar joint was 11.3 degrees +/- 1.4 degrees before surgery and 3.5 degrees +/- 0.8 degrees 2 years after surgery (P = .0060). CONCLUSION: The proposed system has several advantages, including anatomical reconstruction with normal stability and range of motion restored, the need for only a small incision during the reconstruction, and sufficient strength at the tendon graft-bone tunnel junction, in comparison with the tension strength of the lateral ligaments of the ankle.     

The anterior inferior tibiofibular ligament and talar impingement: a cadaveric study

Impingement by the distal fascicle of the anterior inferior tibiofibular ligament (AITFL) is a relatively new entity among the known causes of anterolateral impingement syndromes of the ankle. This study investigated the anatomy of the anterior inferior tibiofibular ligament and its possible role in talar impingement in 47 ankles of 27 cadavers. The length, width, insertion point to the fibula and the interactions with talus were noted, as was the relationship of the fascicle and talus during different ankle movements before and after incision of the lateral ligaments. A distal fascicle of the AITFL was found in 39 of the 47 ankles (83%) and appeared as a single-complete ligament in the remaining 8 ankles (17%). The fascicle averaged 16.1+/-2.94 mm in length (range 10-21) and 4.2+/-1.00 mm in width (range, 3-7). The insertion point of the fascicle on the fibula averaged 10.3+/-2.27 mm (5-13) distal to the joint level. Contact between the ligament and the lateral dome of the talus was observed in 42 specimens (89.3%). Bending of the fascicle was observed in 8 of these 42 ankles with forced dorsiflexion. These 8 specimens were significantly wider and longer than the specimens without bending of the fascicle. Incision of the anterior talofibular ligament led to bending in dorsiflexion in additional 11 ankles. The total 19 fascicles with bending after incision of the anterior talofibular ligament were significantly longer and inserted more distally than the remaining 20 fascisles without bending. Manual traction simulating distraction during arthroscopic procedures relieved the contact. These findings show that the presence of the distal fascicle of the AITFL and its contact with the talus is a normal finding. However, it may become pathological due to anatomical variations and/or instability of the ankle resulting from torn lateral ligaments. When observed during an ankle arthroscopy, the surgeon should look for the criteria described in the present study to decide whether it is pathological and needs to be resected.     

急性外踝韧带和关节囊撕裂

报告了９０例（９１个踝关节）外踝韧带断裂和关节囊撕裂的病例，指出：外踝韧带断裂和踝前外侧关节囊的撕裂是踝足旋后伤所致；外踝韧带断裂易发生在篮球、足球等运动项目；外踝韧带断裂分为４型，对于运动员的Ⅲ度外踝韧带断裂应给予手术治疗，术后效果令人满意；外踝韧带损伤可导致腓骨长短肌的瞬时反应时延长；术后应加强踝关节跖屈、背伸、内翻和外翻肌力的练习，恢复关节的平衡性和灵活性。     

Magnetic resonance imaging findings of chronic lateral ankle instability

The ankle inversion injury is one of the most common types of injury that is encountered in athletes and active individuals. There are a wide variety of acute injuries associated with ankle inversion, including peroneal tendon tears, osteochondritis dessicans of the talus, anterior talofibular ligament avulsion, peroneal retinaculum avulsion, and calcaneofibular ligament tears. Chronic sequelae include impingement, posttraumatic degenerative arthritis, and an attenuated peroneal retinaculum. Most inversion injuries to the ankle have multiple associated injuries and isolated ligament injuries are uncommon. Chronically, the injured ankle usually demonstrates the injuries found at the time of the initial injury. Subsequently, there is a high frequency of these injuries in patients evaluated for symptoms of chronic lateral ankle instability. A high index of suspicion for the specific types of injuries associated with ankle inversions may result in a higher rate of injury detection and more expeditious and accurate diagnoses. Given the persistence of these injuries seen in patients with chronic posterolateral instability, injury patterns of ankle inversion are important to recognize even in the absence of acute trauma. We review the various types of injuries with their associated magnetic resonance (MR) imaging characteristics seen in patients with chronic lateral ankle instability.