Anterior Talar Translation Research Articles

Outcomes of the Modified-Brostrom Procedure Using Suture Anchor for Chronic Lateral Ankle Instability: a Prospective, Randomized Comparison with the Bone Tunnel Technique

Purpose: This study was performed prospectively and randomly to compare the clinical outcomes of modified-Brostrom procedures using the suture anchor and the bone tunnel for chronic lateral ankle instability. Materials and Methods: Thirty patients were followed up for more than 1 year after the modified-Brostrom procedures. Fifteen procedures treated with a suture anchor and 15 procedures treated with a bone tunnel technique assigned randomly were performed by a single surgeon. The clinical evaluation was performed according to the VAS for pain, the Karlsson scale and Sefton grading system. Measurements of the talar tilt and anterior talar translation was performed using anterior and varus stress radiographs. Results: There were no significant differences in the pain VAS between the 2 techniques postoperatively. However, the pain VAS at postoperative 4th day was significantly higher in the bone tunnel group. The Karlsson scale had improved significantly from a preoperative average of 45.2 points to 90.1 points in the suture anchor group, and from 44.6 points to 88.3 points in the bone tunnel group. According to the Sefton grading system, 13 cases (86.7%) in the suture anchor group and 12 cases (80%) in the bone tunnel group achieved satisfactory results. The talar tilt angle and anterior talar translation had improved significantly from preoperative average of and 6.2 mm to and 4.5 mm in the suture anchor group, from and 6.4 mm to and 4.2 mm in the bone tunnel group. There were no significant differences between 2 techniques. Conclusion: The techniques for ligament reattachment produced similar clinical and functional outcomes except for earlystage postoperative pain. Both modified-Brostrom procedures using the suture anchor and bone tunnel appear to be effective treatment methods for chronic lateral ankle instability. However, the suture anchor technique has an advantage of less early-stage postoperative pain.

The deficit of joint position sense in the chronic unstable ankle as measured by inversion angle replication error

Functional instability is defined as a repeated ankle inversion sprain and a giving way sensation. Previous studies have described the damage of sensori-motor control in ankle sprain as being a possible cause of functional instability. The aim of this study was to evaluate the inversion angle replication errors in patients with functional instability after ankle sprain. The difference between the index angle and replication angle was measured in 12 subjects with functional instability, with the aim of evaluating the replication error. As a control group, the replication errors of 17 healthy volunteers were investigated. The side-to-side differences of the replication errors were compared between both the groups, and the relationship between the side-to-side differences of the replication errors and the mechanical instability were statistically analyzed in the unstable group. The side-to-side difference of the replication errors was 1.0 +/- 0.7 degrees in the unstable group and 0.2 +/- 0.7 degrees in the control group. There was a statistically significant difference between both the groups. The side-to-side differences of the replication errors in the unstable group did not statistically correlate to the anterior talar translation and talar tilt. The patients with functional instability had the deficit of joint position sense in comparison with healthy volunteers. The replication error did not correlate to the mechanical instability. The patients with functional instability should be treated appropriately in spite of having less mechanical instability.

The Effect of Estradiol and Progesterone on Knee and Ankle Joint Laxity

Background Female athletes suffer a higher incidence of anterior cruciate ligament injuries compared to their male counterparts, and they appear to be at increased risk for these injuries when they have increased anterior-posterior knee laxity and at specific phases of the menstrual cycle. Although the mechanism by which these factors combine to increase injury risk is unclear, studies suggest that cyclic variations in joint laxity produced by hormone fluctuation during the menstrual cycle pre-dispose an athlete to increased risk of ligamentous injury. Little is known about whether joint laxity varies cyclically during the menstrual cycle and if so, whether it is modulated by cyclic variations of estradiol (E2) and progesterone (P4). Hypothesis Increased serum estradiol (E2) and progesterone (P4) levels are associated with increased ankle and knee joint laxity. Study Design Cohort study. Level of evidence, 2. Methods Ankle laxity, anterior-posterior knee laxity, and serum concentrations of estradiol (E2) and progesterone (P4) were measured during the menstrual cycle in women and at corresponding time intervals in men (controls). Ankle laxity was measured from stress radiographs and included anterior talar translation relative to the tibia and talar tilt relative to the tibia; anterior-posterior knee laxity was measured with the KT-1000 arthrometer. Results Women had greater knee and ankle laxity values compared to men. There was, however, no change in knee and ankle laxity over the normal menstrual cycle in women and no change over time in men. There was no relationship between estradiol and progesterone fluctuation and ankle and knee joint laxity. Conclusions Knee and ankle joint laxities are greater for women compared to men; however, the cyclic estradiol and progesterone fluctuations that occur during the menstrual cycle do not produce cyclic fluctuations of joint laxity. Studies using joint laxity to identify a subject at risk for ligamentous injury need only consider making measurements at a specific point in time, such as during a preseason screening evaluation.

Radiographic measurement of anterior talar translation in the ankle: determination of the most reliable method

Background. Although most would agree that stress radiography is an important research tool to evaluate the integrity of the ankle ligaments in studies of chronic ankle instability, there is little agreement with regard to the best technique to make these measurements. The primary objective of this study was to establish the most reliable method for measuring anterior displacement of the talus relative to the tibia using stress radiographs of the ankle. This information is necessary to standardize radiographic evaluation of injured ankles and for biomechanical studies of the ankle joint, but has never been investigated. Methods. This study examined the reliability of four available methods by measuring the intra-observer repeatability and inter-observer reproducibility of three different investigators. Lateral radiographs were obtained while the ankle was supported in the Telos device with the joint unloaded, and then with a 150 N anterior directed load applied to the calcaneus. At two separate time intervals, the radiographs were read by three different observers using four measurement techniques. For each technique, the measurement of the unloaded ankle was subtracted from the loaded ankle to obtain anterior talar translation. Findings. The method that measured the shortest distance between the posterior lip of the distal tibia and the talar dome (designated Method I in the current series) was significantly more reproducible between readers and within readers across repeated measurements than the other methods tested. Interpretation. Based on the findings from this study, it can be concluded that measurement of the distance between the posterior lip of the distal tibia and the talar dome is the method of choice to characterize the position of the talus relative to the tibia in stress radiography. In order to standardize the radiographic evaluation of ankle injuries, this method should be the one employed to measure anterior talar translation.

Twenty-year results of the Evans operation for lateral instability of the ankle.

Twenty-four patients (25 ankles), operated on using the static modification of the Evans tenodesis for lateral instability, were evaluated 19 to 21 years after surgery. Twelve of the patients (12 ankles) had excellent results, seven patients (eight ankles) had good results, three patients (three ankles) had fair results, and two patients (two ankles) had poor results. The subjective results had no clear correlation to the stress radiographs, which showed minor or moderate anterior talar translation in 10 ankles. Moreover, the difference between the surgically treated and the contralateral ankle was not significant. Static modification of the Evans tenodesis is recommended if an anatomic reconstruction of the lateral ligaments is not feasible (general laxity of joints, reoperation).

Anatomical reconstruction and Evans tenodesis of the lateral ligaments of the ankle

In this retrospective study, we assessed the outcome in 99 patients who underwent reconstruction of the lateral ligaments of the ankle for chronic anterolateral instability with a minimum follow-up of 15 years. Two techniques were compared: 54 patients had an anatomical reconstruction (AR group) and 45 had an Evans tenodesis (ET group). They were followed up for 19.9 ± 3.6 years and 21.8 ± 4.6 years, respectively. During follow-up, seven patients in the AR group and 17 in the ET group required a further operation (p = 0.004). At follow-up, significantly more patients (n = 15) in the ET group had limited dorsiflexion than in the AR group (n = 6, p = 0.007) and 18 in the ET group had a positive anterior drawer test compared with seven in the AR group (p = 0002). In the ET group 27 had tenderness on palpation of the ankle compared with 15 in the AR group (p = 0.001). Stress radiographs showed ligamentous laxity significantly more often in the ET group (n = 30) than in the AR group (n = 13, p < 0.001). The mean values for talar tilt and anterior talar translation were significantly higher in the ET group than in the AR group (p < 0.001, p = 0.007, respectively). There were degenerative changes on standard radiographs in 32 patients in the AR group and 35 in the ET group (p = 0.05). Four patients in the ET group had developed severe osteoarthritis compared with none in the AR group (p = 0.025). Assessment of functional stability revealed a mean Karlsson score of 83.7 ± 10.4 points in the AR group and 67.0 ± 15.8 points in the ET group (p < 0.001). According to the Good rating system, 43 patients in the AR group had good or excellent results compared with 15 in the ET group (p < 0.001). Compared with anatomical reconstruction, the Evans tenodesis does not prevent laxity in a large number of patients. Long-standing ligamentous laxity leads to degenerative change in the ankle, resulting in chronic pain, limited dorsiflexion and further operations. The functional result deteriorates more rapidly after the Evans tenodesis than after anatomical reconstruction.

Anatomical reconstruction and Evans tenodesis of the lateral ligaments of the ankle. Clinical and radiological findings after follow-up for 15 to 30 years.

In this retrospective study, we assessed the outcome in 99 patients who underwent reconstruction of the lateral ligaments of the ankle for chronic anterolateral instability with a minimum follow-up of 15 years. Two techniques were compared: 54 patients had an anatomical reconstruction (AR group) and 45 had an Evans tenodesis (ET group). They were followed up for 19.9+/-3.6 years and 21.8+/-4.6 years, respectively. During follow-up, seven patients in the AR group and 17 in the ET group required a further operation (p = 0.004). At follow-up, significantly more patients (n = 15) in the ET group had limited dorsiflexion than in the AR group (n = 6, p = 0.007) and 18 in the ET group had a positive anterior drawer test compared with seven in the AR group (p = 0002). In the ET group 27 had tenderness on palpation of the ankle compared with 15 in the AR group (p = 0.001). Stress radiographs showed ligamentous laxity significantly more often in the ET group (n = 30) than in the AR group (n = 13, p < 0.001). The mean values for talar tilt and anterior talar translation were significantly higher in the ET group than in the AR group (p < 0.001, p = 0.007, respectively). There were degenerative changes on standard radiographs in 32 patients in the AR group and 35 in the ET group (p = 0.05). Four patients in the ET group had developed severe osteoarthritis compared with none in the AR group (p = 0.025). Assessment of functional stability revealed a mean Karlsson score of 83.7+/-10.4 points in the AR group and 67.0+/-15.8 points in the ET group (p < 0.001). According to the Good rating system, 43 patients in the AR group had good or excellent results compared with 15 in the ET group (p < 0.001). Compared with anatomical reconstruction, the Evans tenodesis does not prevent laxity in a large number of patients. Long-standing ligamentous laxity leads to degenerative change in the ankle, resulting in chronic pain, limited dorsiflexion and further operations. The functional result deteriorates more rapidly after the Evans tenodesis than after anatomical reconstruction.

Ankle Sensorimotor Control and Eversion Strength after Acute Ankle Inversion Injuries

We performed this study to monitor changes in ankle eversion strength and sensorimotor control functions after acute ankle inversion injury. Forty-four patients with clinical grade II to III first-time ankle inversion sprains were tested for 1) pathologic talar tilt and anterior talar translation at 1 and 12 weeks after injury; 2) isometric eccentric ankle eversion strength and 3) peroneal reaction time to sudden ankle inversion at 3, 6, and 12 weeks after injury; and 4) accuracy of inversion position assessment 1, 3, 6, and 12 weeks after injury. Not all patients could perform all tests at the early follow-up visits. There was mechanical instability in 19 of 40 tested patients at 1 week and in 4 patients at 12 weeks after injury. Eversion strength was 88% of the contralateral side 3 weeks after injury, rising to 96% after 12 weeks. The magnitude of error of inversion position sense was 190% of the contralateral side 1 week after injury; this was still affected after 12 weeks, but fell to 133%. Patients with pathologic talar tilt or anterior talar translation, or both, at 1 week after injury did not show significantly greater error in position assessment or reduction in eversion strength when compared with patients with ankles that remained stable after injury.

The effect of external ankle support in chronic lateral ankle joint instability

We examined the effect of ankle taping on ankle joint stability by measuring mechanical stability using stand ardized stress radiographs. Anterior talar translation and talar tilt, both with and without ankle tape, were examined. The reduction of anterior talar translation and talar tilt with tape as compared to without tape was insignificant.The reaction time of the peroneus muscles was measured by electromyographic signal after a simulated ankle sprain on a tilting trapdoor. The reaction time was significantly slower in the unstable ankles of 20 athletes with unilateral ankle instability than in the stable contra lateral ankles. With tape, the reaction time was signifi cantly shortened, although not back to normal. The greatest improvement in reaction time was achieved in ankles with the highest degree of mechanical instability. Thus, the mechanism behind the function of ankle tape may be to restrict the extremes of ankle motion and to help shorten the reaction time of the peroneus muscles by affecting ...

The Unstable Ankle: A Combined EMG and Biomechanical Modeling Study

A device to simulate ankle motion associated with inversion ankle injury was constructed. This device consists of a trap door that can be tilted 30° from the horizontal plane. Surface EMG electrodes were placed over the peroneus brevis and peroneus longus muscles. The time measured from the tilting of the plate to the first muscular response on the EMG was defined as the reflex time. Twenty individuals with unilateral ankle joint instability were tested. The mechanical ankle joint stability was measured using standardized radiographic measurements, taking into account anterior talar translation and talar tilt. The mean anterior talar translation was 5.9 mm and the mean talar tilt was 3.2° in the stable ankles, compared to 12.7 mm and 10.5° for the unstable ankles. The mean reflex time was 68.8 ms (peroneus longus) and 69.2 ms (peroneus brevis) in the stable ankles as compared to 84.5 ms (peroneus longus) and 81.6 ms (peroneus brevis) in the unstable ankles. Important factors influencing functional instability are discussed.

The effect of external ankle support in chronic lateral ankle joint instability. An electromyographic study.

We examined the effect of ankle taping on ankle joint stability by measuring mechanical stability using standardized stress radiographs. Anterior talar translation and talar tilt, both with and without ankle tape, were examined. The reduction of anterior talar translation and talar tilt with tape as compared to without tape was insignificant. The reaction time of the peroneus muscles was measured by electromyographic signal after a simulated ankle sprain on a tilting trapdoor. The reaction time was significantly slower in the unstable ankles of 20 athletes with unilateral ankle instability than in the stable contralateral ankles. With tape, the reaction time was significantly shortened, although not back to normal. The greatest improvement in reaction time was achieved in ankles with the highest degree of mechanical instability. Thus, the mechanism behind the function of ankle tape may be to restrict the extremes of ankle motion and to help shorten the reaction time of the peroneus muscles by affecting the proprioceptive function of the ankle.

Radiographic Evaluation of Ankle Joint Stability

Ankle joint stability was evaluated in 120 patients with functional instability (FI) of the ankle and in a control group with functionally stable (FS) ankle joints. It was also compared in patients with unilateral ankle joint instability. The radiographic investigation was standardized using the same method, instruments, and calculations. The anterior talar translation (ATT) for men was 10.5 mm (range 8–15 mm) in functionally unstable ankle joints and 7.3 mm (range 4–11 mm) in the control group (p < 0.001). The corresponding values for women were 11.3 mm (range 6–24 mm) and 7.2 mm (range 3–12 mm) (p < 0.001). The talar tilt (TT) was significantly (p < 0.001) higher in the functionally unstable ankle joints than in the control group: 10° (range 3°-27°) and 3.2° (range 0°-8°) for men and 11° (range 2°-23°) and 4.3° (range 0°-8°) for women. ATT in patients with unilateral functional instability was 11.1 mm (range 7–20 mm) as compared with 7.9 mm (range 4–11 mm) in the stable group (p < 0.001). TT was 9.5° (range 3°-23°) degrees in the functionally unstable ankles as compared with 4.4° (range 2°-8°) in the stable ankles (p < 0.001). The mean difference between functionally stable and unstable ankle joints was 3.2 mm (ATT) and 5.1° (TT). Mechanical instability (MI) can be defined as an ATT ≥ 10 mm and a TT ≥ 9°, or a difference in ATT and TT between stable and unstable ankle joints >3 mm and 3°, respectively. Mechanical instability is an important factor in development of functional instability of the ankle. Standardized stress radiographs are of definite value in diagnostic evaluation of ankle joint stability.

Evaluation of ankle joint function: the use of a scoring scale

A scoring scale for evaluation of ankle joint function is presented. The scoring scale is compared to a functional scale, a visual analogue scale and tested against anterior talar translation (ATT) and talar tilt (TT) on standardized stress radiographs. The scoring scale correlates statistically with the subjective and objective parameters of ankle joint stability and function. We have found the scale easy to use and to correlate well with the subjective and objective status of the ankle joint, and conclude that it is a useful tool in the assessment of ankle joint function. It can be used to compare different series and in scientific work.

Long-term results of the Evans procedure for lateral instability of the ankle

We studied the late outcome of 40 ankles (from a consecutive series of 42) treated by a modified Evans procedure. The peroneus brevis tendon was used to fashion a static tenodesis. All the patients had suffered from persistent lateral instability following an ankle sprain. The follow-up period was between nine and 12 years. Excellent or good results were achieved in 33 ankles (82.5%), three had a fair result, and four were poor. The clinical results were matched by the radiographic results which showed significant talar tilt or anterior talar translation in only three ankles. The functional result showed no positive correlation with the stress-radiographic analysis. We concluded that this modification of the Evans operation gives satisfactory long-term results, which show little change from the good results at 24 to 35 months reported in an earlier paper from our department.

Surgical treatment of chronic lateral instability of the ankle joint. A new procedure.

Sixty patients with chronic lateral functional and mechanical instability of the ankle joint were treated with shortening and reinsertion of the lateral ankle ligaments. All patients were followed prospectively for 2 to 5 years (mean, 3 years 6 months). We found the functional results to be excellent or good in 53 patients (88%). Patients with unsatisfactory results had either generalized joint hypermobility or long-standing ligament insufficiency. Anterior talar translation (ATT) and talar tilt (TT) were measured radiologically on standardized radiographs. Patients with excellent and good functional results had better mechanical stability, both ATT and TT, than those with fair and poor functional results. A good correlation was found between clinical, functional, and radiological results. In conclusion we found that reconstruction of the ankle stability by shortening and reinsertion of the lateral ankle ligaments is a safe and simple method and is a good alternative to other more complex methods of ligament reconstruction. The method should, however, be used with great care in patients with generalized joint hypermobility or in patients with long-standing ligament insufficiency.

Lateral instability of the ankle treated by the Evans procedure. A long-term clinical and radiological follow-up.

We have reviewed 42 of 52 consecutive patients at an average of 14 years after a tenodesis based on Evans' operation performed for chronic lateral instability of the ankle. Only 21 patients (50%) had satisfactory long-term functional results, and 12 patients with satisfactory early results had deteriorated after three to six years. Stress radiographs were used to measure anterior talar translation and talar tilt, and a good correlation was found between function and mechanical stability. Talar tilt had been controlled more successfully than anterior translation. Marginal osteophytes were found in most ankles, and were larger and more numerous in those with the greatest instability.