Narrowing the Normal Range for Lateral Ankle Ligament Stability with Stress Radiography

Stress radiographs are commonly performed to evaluate lateral ankle ligament stability; however, little agreement exists on the physiologic limits obtained from the anterior drawer and talar tilt stress tests. Published studies have reported the normal range for the anterior drawer test to be 3 to 10 mm and the normal range for the talar tilt test to be 0° to 23° for the uninjured ankle, leading to inconsistent interpretation. The primary objective of the present study was to narrow the threshold for the diagnosis of ankle ligament injury using stress radiographs by refining the values seen in the normal ankle. An improved understanding of normal ankle motion could allow for a more accurate determination of ligament injury using stress imaging. Conducted in a simplified, yet reproducible, manner, we hoped the present study would draw a parallel with generalized use in an office setting and would allow physicians the ability to more effectively diagnose ankle ligament injury. Bilateral radiographic images of anterior drawer and talar tilt stress tests were taken of 50 participants (100 ankles) with no history of ankle fracture or surgical intervention for ankle instability. Participants with a previous ankle sprain were later excluded from the result computations. Factors such as patient age and gender were evaluated. In the final analysis, 46 participants (76 ankles) were included, with a mean anterior drawer test result of 2.00 mm ± 1.71 mm and talar tilt test result of 3.39° ± 2.70° in the normal ankle. The results of the present study suggest that stress radiographs for lateral ankle stability can be performed in a simple and reliable manner. These results also support a much lower threshold for the diagnosis of lateral ankle injury than previously reported.     

"Normal" talar tilt angle.

A study to determine the degree of normal talar tilt in individuals with no history of ankle injuries was performed on 404 ankles of 202 midshipmen at the U.S. Naval Academy. Manual inversion stress roentgenograms were used to test this group of young healthy adults, most of whom were males. Of the 404 ankles tested, only 39 (9.7%) had any measurable talar tilt and only 7 ankles (1.7%) had a tilt over 5 degrees. Normal talar tilt does not range to 23 degrees. A normal ankle in a healthy young adult with no history of trauma has a small probability of having any talar tilt. When stress roentgenograms are used to evaluate a fresh lateral ankle ligament sprain in this type of individual, there is a very high probability that talar tilt over 5 degrees would represent significant injury to one or more of the lateral supporting structures.     

Diagnosis of lateral ankle ligament injuries: Comparison between talar tilt, MRI and operative findings in 112 athletes

We evaluated the reliability of the radiographic talar tilt test by MRI examinations in 112 athletes with injuries to the lateral ligaments of the ankle. 25 athletes with a talar tilt 15° were treated operatively. Intraoperative findings and the talar tilt test were compared with MR imaging results. Our results suggest that MRI is a reliable method for diagnosing injuries of the lateral ankle ligaments. the talar tilt test cannot evaluate the specific pathology of lateral ankle ligaments, but it was reliable in indicating complete double-ligament ruptures (anterior talofibular and calcaneo-fibular ligaments), when talar tilt was 15° or more than on the uninjured side.     

Reconstruction for chronic lateral ankle instability using the palmaris longus tendon: is reconstruction of the calcaneofibular ligament necessary?

The palmaris longus tendon was used to reconstruct the anterior talofibular ligament (ATFL) in 27 ankles with chronic lateral instability. The mean age of the patients at surgery was 23 years, and the follow-up was more than 2 years. The functional evaluation showed excellent or good results in all ankles. Twenty-seven ankles were divided into two groups according to operative findings: group A consisted of 11 ankles with old isolated injury of the ATFL, and group B consisted of 16 ankles with old combined injuries of the ATFL and the calcaneofibular ligament. There were no significant differences in clinical results between group A and group B. The preoperative mean talar tilt angles on stress radiograph in group B were significantly larger than those in group A. At follow-up, there were no significant differences in the mean talar tilt angles between group A and group B. We demonstrate that reconstruction of the calcaneofibular ligament along with the ATFL is not necessary for patients with chronic combined lateral ligament instability.     

The effect of partial deltoid ligament injuries on the external rotation stability: A cadaveric study

BackgroundThe anterior and posterior part of the deltoid ligament have different functions during ankle flexion motion. Partial ligament injuries have been demonstrated in previous clinical reports. However, the efficacy of external rotation stress test in partial injured cases is unavailable till now.MethodsThirty-two fresh cadaveric specimens were included and allocated into two destabilization groups. In the first group, the anterior portion of deltoid ligament (DL) and syndesmotic ligament were sequentially severed, while in the second group, the posterior portion of DL and syndesmotic ligament were sequentially severed. Mortise view radiographs were taken after each destabilization stage when the ankles were placed at plantarflexion and dorsiflexion positions and stressed in standard external rotation force. The medial clear space (MCS) and talar tilt (TT) angle were measured and compared among different destabilization stages.ResultsWhen the ankles were placed at neutral position, the TT significantly increased in all destabilization stages. The MCS significantly increased after the partial deltoid ligament ruptures only with presence of syndesmotic ligament injuries. There was no significant difference of MCS at plantarflexion for all stages of destabilization if the anterior portion of DL is preserved. Similarly, no significant increase of MCS was detected at dorsiflexion if the posterior portion of DL and posterior inferior tibiofibular ligament are intact.ConclusionPartial DL rupture causes ankle rotational instability at different ankle joint positions, especially when combined with syndesmotic injuries. The neutral position is recommended for diagnosis of partial DL ruptures under external rotation stress.     

Lack of Definition of Chronic Ankle Instability With Arthrometer-Assisted Ankle Joint Stress Testing: A Systematic Review of In Vivo Studies

Despite extensive research on ankle instability a consensual and clear objective definition for pathological mechanical lateral ankle instability is yet to be determined. This systematic review aimed to summarize current available arthrometric devices, measuring methods and lateral ankle laxity outcomes in patients with chronic ankle instability that underwent objective arthrometric stress measurement. Sixty-eight studies comprising a total of 3,235 ankles with chronic ankle instability were included. Studies reported a wide range of arthrometric devices, testing position and procedures, and measuring methods. For the anterior drawer test, the average mean differences between injured and uninjured ankles ranged from -0.9 to 4.1 mm, and total translation in the injured ankle from 3.2 to 21.0 mm. Most common pathological threshold was ≥4 mm or ≥10 mm unilaterally and ≥3 mm bilaterally. For the talar tilt test, the average mean differences between injured and uninjured ankles ranged from 0.0° to 8.0°, and total tilt from injured ankle from 3.3 to 60.2°. Most common pathological threshold was ≥ 10° unilaterally and ≥ 6° mm bilaterally. It was found high heterogeneity in the scientific literature regarding the arthrometric devices, use of concomitant imaging and measuring methods of arthrometer-assisted anterior drawer and talar tilt tests which led to variable laxity outcomes in individuals with chronic ankle instability. Future studies should focus on standardizing the testing and measuring methods for an objective definition of mechanical ankle instability.     

The effect of lateral ankle sprain on dorsiflexion range of motion, posterior talar glide, and joint laxity

STUDY DESIGN: Retrospective study. Objective: Assess range of motion, posterior talar glide, and residual joint laxity following ankle sprain in a population of athletes who have returned to unrestricted activity. BACKGROUND: Lateral ankle sprains occur frequently in athletic populations and the reinjury rate may be as high as 80%. In an effort to better understand risk factors for reinjury, the sequelae to injury in a sample of college athletes were assessed. METHODS AND MEASURES: Twelve athletes with a history of lateral ankle sprain within the last 6 months and who had returned to sport participation were tested. Only athletes who reported never injuring the contralateral ankle were included. The injured and uninjured ankles of subjects were compared for measures of joint laxity, ankle dorsiflexion range of motion, and posterior talar glide. Friedman's test of rank order was used to analyze the laxity measures and a MANOVA was used to assess the dorsiflexion and posterior talar glide measures. RESULTS: Laxity was significantly greater at the talocrural and subtalar joints of the injured ankles. There were no significant differences in any of the ankle dorsiflexion measurements between injured and uninjured ankles, but posterior talar glide was significantly reduced in injured ankles as compared to uninjured ankles. CONCLUSION: In our sample of subjects, residual ligamentous laxity was commonly found following lateral ankle sprain. Dorsiflexion range of motion was restored in the population studied despite evidence of restricted posterior glide of the talocrural joint. Although restoration of physiological range of motion was achieved, residual joint dysfunction persisted. Further research is warranted to elucidate the role of altered arthrokinematics after lateral ankle sprain.     

In vitro evaluation of the effect lateral process talar excision on ankle and subtalar joint stability

BACKGROUND: Recent literature reflects a substantial increase in interest surrounding lateral talar process fractures. Previous anatomic investigations discovered that excision of a 1 cm3 fracture fragment from the lateral talar process involves approximately 100% of the lateral talocalcaneal ligament origin and 10% to 15% of both the posterior and anterior talofibular ligament insertions. The objective of this study was to determine the effect that excision of this 1 cm3 fragment has on ankle and subtalar joint stability. METHODS: Ten fresh-frozen cadaver lower limbs were thawed before testing and placed in a clinical stress apparatus (Model SE 20, Telos, Marburg, Germany). Radiographs were taken before and after application of a 150 N of force. Three views (lateral, anteroposterior, 30-degree Bróden) were used to asses anterior tibiotalar translation (AT), talar tilt (TT), medial talocalcaneal motion (TCM), and talocalcaneal tilt (TCT) before and after excision of the 1 cm3 fragment the lateral talar process. RESULTS: The mean increases in AT, TT, TCM and TCT after excision of the 1 cm3 fragment were: AT=1.0 mm+/-0.94 mm (p=0.0085); TT=0.4+/-0.52 degrees (p=0.0368); TCM=1.0 mm+/-1.25 mm (p=0.0319); TCT=1.2+/-1.32 degrees (p=0.0181). CONCLUSIONS: Since it has been generally accepted that a 3 mm increase in AT, 3-degree increase in TT, 5-mm increase in TCM, more than 5-degree increase in TCT define instability of the ankle and subtalar joints, respectively. These results suggest that excision of a 1 cm3 fragment causes neither ankle nor subtalar instability as defined by radiographic stress examination.     

Biomechanics Following Anatomic Lateral Ligament Repair of Chronic Ankle Instability: A Systematic Review

One of the most common orthopedic injuries in the general population, particularly among athletes, is ankle sprain. We investigated the literature to evaluate the known pre- and postoperative biomechanical changes of the ankle after anatomic lateral ligament repair in patients suffering from chronic ankle instability. In this systematic review, studies published till January 2020 were identified by using synonyms for “kinetic outcomes,” "kinematic outcomes,” “Broström procedure,” and “lateral ligament repair.” Included studies reported on pre- and postoperative kinematic and/or kinetic data. Twelve articles, including 496 patients treated with anatomic lateral ligament repair, were selected for critical appraisal. Following surgery, both preoperative talar tilt and anterior talar translation were reduced similarly to the values found in the uninjured contralateral side. However, 16 of 152 (10.5%) patients showed a decrease in ankle range of motion after the surgery. Despite the use of these various techniques, there were no identifiable differences in biomechanical postoperative outcomes. Anatomic lateral ligament repair for chronic ankle instability can restore ankle biomechanics similar to that of healthy uninjured individuals. There is currently no biomechanical evidence to support or refute a biomechanical advantage of any of the currently used surgical ligament repair techniques mentioned among included studies.     

Kinematic behavior of the ankle following malleolar fracture repair in a high-fidelity cadaver model

BACKGROUND: Previous studies involving axially loaded ankle cadaver specimens undergoing a passive range of motion after fracture have demonstrated rotatory instability patterns consisting of excessive external rotation during plantar flexion. The present study was designed to expand these studies by using a model in which ankle motion is controlled by physiologically accurate motor forces generated through phasic force-couples attached to the muscle-tendon units. METHODS: Eight right unembalmed cadaver feet were tested in a dynamic gait simulator that reproduces the sagittal kinematics of the tibia while applying physiological muscle forces to the tendons of the major extrinsic muscles of the foot. Six-degrees-of-freedom kinematics of the tibia and talus were measured with use of a VICON motion-analysis system. The experimental conditions included all combinations of lateral and medial injury to reproduce the clinical classifications of ankle fracture. Statistical analysis was performed with repeated-measures analyses of variance. RESULTS: The talus of the intact ankles demonstrated coupled external rotation and inversion relative to the tibia as the ankle plantar flexed. Osteotomy of the fibula, simulating a lateral ankle fracture, slightly but significantly increased external rotation and inversion of the talus (p < 0.001), whereas disruption of either the superficial or the deep deltoid ligament increased talar eversion (p < 0.003) and disruption of the deep deltoid ligament increased internal rotation (p < 0.0001). The aberrant motions were corrected by repair of the injured structure. CONCLUSIONS: The predominant coupled rotation of the talus is external rotation associated with plantar flexion. Following progressive ankle destabilization, talar external rotation and inversion increased. Clinical Relevance: The clinical decision-making process regarding the treatment of ankle fractures centers on determination of whether the injury is expected to result in abnormal motion, which is thought to predispose to the development of arthritis. The present study demonstrated a remarkable degree of ankle stability during stance phase even when there was severe disruption of medial and lateral structures. This finding suggests that a main determinant of clinical outcome after ankle fracture may be ankle motion during swing phase, when ankle stability is not augmented by the combination of axial loading and active motor control of motion. If swing-phase motion is abnormal, then the ankle may be in a vulnerable position at the point of heel-strike.     

Treatment of lateral ankle ligament tears. Operative or conservative?

In lateral ankle ligament tears, the anterior talofibular ligament ruptures most commonly, often in conjunction with the calcaneofibular ligament. The posterior talofibular ligament is rarely affected. Associated injuries at the adjacent ligamentous structures or at the articular cartilage of the ankle commonly occur. The diagnosis is established clinically with the anterolateral drawer sign and an increased lateral talar tilt. Stress radiographs in two planes demonstrate talar tilt and anterior displacement of the talus, in comparison to the unaffected side. Magnetic resonance imaging provides an early diagnosis of concomitant injuries. Simple, acute lateral ankle ligament tears are treated non-operatively. Surgery is indicated in dislocated bone avulsions and in chondral or osteochondral fractures. A recurrent tear in an athletic patient should also be treated operatively. Athletic endeavours, the number of torn ligaments and patient age are no useful indicators for surgical treatment. Conservative treatment consist of oedema therapy, immobilization of the fibular ligaments with as little compromise of ankle joint function as possible, and rehabilitation with muscle strengthening and proprioception training. During surgery, the ligament stumps are reapproximated in anatomic position, reinforced with local tissue if necessary, and the articular surface is examined for concomitant injuries.     

Comprehensive reconstruction of the lateral ankle for chronic instability using a free gracilis graft

PURPOSE: The purpose of this retrospective study was to assess the results of a novel surgical technique for the treatment of chronic lateral ankle instability using both a direct repair of the anterior talofibular ligament and a free gracilis tendon transfer to reconstruct anatomically the anterior talofibular and calcaneofibular ligaments. METHODS: Between December 1998 and February 2002, 28 patients (29 ankles) underwent an anatomic reconstruction of the lateral ankle ligaments for chronic ankle instability. Patients returned for a clinical and radiologic follow-up evaluation at an average of 23 months following surgery (range, 12-52 months). Outcomes were assessed by comparison of preoperative and postoperative American Orthopaedic Foot and Ankle Society (AOFAS) scores and visual analog pain scores as well as a postoperative Karlsson score. A subjective self-assessment rating was also obtained. All patients underwent preoperative and postoperative radiographic assessment including talar tilt and anterior drawer stress radiographs. RESULTS: Twenty-eight patients (29 ankles) (100%) returned for final evaluation. Good or excellent outcome was noted on patient subjective self-assessment, pain scores, AOFAS, and Karlsson scores at final follow-up in all patients. Ankle range of motion was not affected by lateral ankle reconstruction. The talar tilt was reduced from a mean of 13 degrees to 3 degrees (p <.0001) and the anterior drawer was reduced from a mean of 10 mm to 5 mm (p <.0001) by the lateral ankle ligamentous reconstruction. CONCLUSION: In the present study, lateral ankle reconstruction with a direct anterior talofibular ligament repair and free gracilis tendon graft augmentation resulted in a high percentage of successful results, excellent ankle stability with a minimal loss of ankle or hindfoot motion, and marked reduction of pain at an average follow-up of almost 2 years.     

Subluxatio supinatoira tali

A talar tilt of approximately 15° or more is the indication for operative treatment of ruptures of the lateral ligaments of the ankle. Until 1978 stress x-rays were made with the films held by hand in short general anaesthesia. 84% of the x-rays held in plantar flexion of the ankle joint showed a greater talar tilt than if held in the S-O position. There was no direct connection between the degree of the anterior drawer sign and the degree of the talar tilt. After a personal information from H. Frick, since 1978 in 47 patients stress films were taken first without anaesthesia followed by films in general anaesthesia: The patient is positioned on his uninjured side. The injured leg lies horizontally on a support, the foot extends beyond the x-ray table. A cuff is applied, from which a weighted flap is put over the lateral side of the foot. After approximately 5 minutes an ap-x-ray is made. The talar tilt is generally about 25% less than in general anaesthesia. Using this method, in 1979 an increased number of ruptured lateral ligaments of the ankle was diagnosed. In 90% the indication for operation was made by this method alone. In only 5%, after insufficient talar tilt despite sufficient clinical evidence additional stress films under general anaesthesia were made, which then gave the indication for operation. Since with both methods complete muscle relaxation is not achieved we could find no definite relation between the operative findings and the amount of talar tilt. At the follow up examination the operated ruptures of the lateral ligaments of the ankle joint showed better results than those treated conservatively, in spite of the fact that conservative treatment was used with a talar tilt of up to 15° and operative treatment chosen with a talar tilt above 15°. At follow up no talar tilt was found among 33% of the operated patients, but only among 16% of conservatively treated cases. A talar tilt was found in over 50% of our patients on the healthy side, without a history of injury.     

Experimental instability of the ankle. A radiographic investigation

For determination of the optimal position in examining the ankle joint for anterior drawer sign and talar tilting, 12 legs freshly amputated above the knee were radiographically examined after successive transection of the lateral ankle ligaments in three different sequences. Apparatuses secured the position of the ankle joint in 25 degrees of inward rotation and 10 degrees and 30 degrees, respectively, of plantarflexion. Examination for anterior drawer sign gave significantly greater displacement with the foot in 10 degrees than with the foot in 30 degrees of plantarflexion and was most pronounced after the cutting of the anterior talofibular ligament. Examination for talar tilt gave a non-significantly greater displacement at 10 degrees of plantarflexion, except when cutting both the posterior talofibular and the anterior talofibular ligament. Isolated cutting of the calcaneofibular ligament gave only little displacement irrespective of the method used. Radiographic examination should be performed with 10 degrees of plantarflexion to obtain maximal displacement and 25 degrees of inward rotation of the leg to obtain a free ankle mortise in the anteroposterior projection and concentric arcs of the joint surfaces in the side projection.     

Chronic lateral instability of the ankle. Roentgen stereophotogrammetry of talar position

Using roentgen stereophotogrammetric analysis (RSA), we investigated the talar mobility in 54 ankles during the anterior drawer and adduction tests. Talar tilt was increased in ankles with unilateral symptoms of chronic lateral instability. No other difference in talar tilt and anterior drawer sign was noted comparing ankles with and without symptoms. We conclude that mechanical tests cannot always verify the diagnosis "chronic lateral instability of the ankle".     

Diagnosis and treatment of talar tilt and its relationship to the occurrence of transchondral fractures: a retrospective study

A study of 112 acute ligamentous injuries of the ankle diagnosed with the Telos stress device and repaired surgically was conducted by the authors. They found that the likelihood of a transchondral fracture of the talar dome was significantly increased when the talar tilt was 18 degrees or greater. A significant number of these fractures were not diagnosed until surgical inspection. The authors provide a comprehensive review of transchondral fractures of the talar dome and attempt to correlate the clinical significance of the data obtained in this study with the diagnosis and treatment of these fractures.     

Outcome of the functional treatment of first-time ankle inversion injury

Background  

Avulsion fractures of the lateral malleoli in ankle inversion injuries are often undetected on routine radiographs. Undetected avulsion fractures have been managed as ankle sprain, which may affect the outcome of the treatment of the ankle sprain. The purposes of this study are to compare the outcomes of functional treatment between the first-time severe ligament injury and avulsion fracture of the lateral ankle, and to investigate how the anterior talofibular ligament (ATFL) view or the calcaneofibular ligament (CFL) view affects the diagnosis of the avulsion fracture and outcome of functional treatment of the ankle inversion injury.     

Comparison Between the Simultaneous Reconstructions of the Anterior Talofibular Ligament and Calcaneofibular Ligament and the Single Reconstruction of the Anterior Talofibular Ligament for the Treatment of Chronic Lateral Ankle Instability

This study aimed to evaluate the procedures of reconstruction surgery for chronic lateral ankle instability. We compared single anterior talofibular ligament reconstruction to simultaneous reconstructions of the anterior talofibular and calcaneofibular ligaments. From 2015 to 2019, 14 consecutive patients diagnosed with chronic lateral ankle instability underwent arthroscopic anterior talofibular ligament reconstruction with or without calcaneofibular ligament reconstruction after conservative treatment. Seven patients underwent single anterior talofibular ligament reconstruction (group AT), and 7 patients underwent simultaneous reconstructions of the anterior talofibular ligament and calcaneofibular ligament (group AC). The Japanese Society for Surgery of the Foot scale scores and Karlsson scores significantly improved in all patients 1 year postoperatively. The radiographic measurement of the talar tilt angle and the talar anterior drawer distance at 1 year after surgery were also significantly improved compared to preoperative values. The postoperative talar tilt angle was significantly greater in group AT (median 6°, range 3°-7°) than that in group AC (median 3°, range 2°-5°; p = .038). The postoperative talar anterior drawer distance, Japanese Society for Surgery of the Foot scale score, and Karlsson score were not significantly different between the 2 groups.We found that although the clinical outcomes after the anterior talofibular ligament reconstruction with or without the calcaneofibular ligament reconstruction for chronic lateral ankle instability were good, instability of the talar tilt angle at 1 year postoperatively in patients who underwent single anterior talofibular ligament reconstruction was greater than that in patients who underwent simultaneous anterior talofibular and calcaneofibular ligament reconstructions.     

Involvement of the inner malleolus and deltoid ligament in supination trauma of the ankle joint

Additional ligament ruptures or fractures of the medial side of the ankle joint accompanying the lateral ligament rupture are rare. These injuries are more often in traumas with pronation-eversion movements of the foot. In cases of lateral ligaments ruptures we only found in 2.8% and in 5.9% additional medial injuries. This is confirmed by different biomechanical experiments. Experimentally the delta ligament rupture could mostly be caused by pronation-eversion movements or by forced plantar flexion of the foot. The diagnosis of bony lesions of the medial malleolus might be easy by X-ray, but ligament lesions of the medial ankle joint can be diagnosed easily too be using the stress X-ray controlling the medial talar tilt as a sign of medial instability. Because the necessity of surgical treatment is less important than of the lateral ligaments we recommend this procedure in cases of bilateral instability or if dislocation is obvious.     

Congenital Dislocation of the Head of the Radius

Twenty patients with chronic ankle instability were examined radiographically for anterior talar displacement and talar tilting. The examinations were carried out with the ankles untaped and taped, and the taped ankles were examined again after 20 min running. The measurable instability was significantly improved after taping, but after exercise this was seen only for talar tilting. Generally, the best stabilizing effect of taping was obtained in the ankles with the greatest degree of instability. After exercise, all but one of the adhesive taping bandages were loose and were mostly acting as canvas boots, affording the ankle only limited protection.