Evans' repair of lateral instability of the ankle joint

Revision of Surgical Lateral Ankle Ligament Stabilization

Ankle sprains continue to be among the most common musculoskeletal injuries, most of which never require surgical treatment. Surgical treatment has traditionally been successful for those patients whose symptoms do not improve with nonoperative care. However, recurrent instability, although rare, can occur early or late after a stabilization procedure, as the result of an acute traumatic event or chronic repetitive minor injury. A complete workup of patients with recurrent ankle instability should be completed before revision surgery and should include evaluation for generalized joint hypermobility as well as anatomic variations, such as hindfoot varus, first ray plantarflexion, and midfoot cavus.

Operative management of chronic ankle instability: plantaris graft

Precise knowledge of lateral ankle ligaments anatomy and biomechanics is mandatory for successful surgical reconstruction. The displayed reconstruction procedure fulfilled these requirements, and showed excellent clinical outcome. The described harvesting of the plantaris tendon at the proximal calf allows the use of a relatively long tendon autograft compared with the traditional harvesting procedure at the os calcis. Consequently, this procedure gives the surgeon a more efficient access to a local tendon autograft for numerous surgical procedures in the field of foot and ankle surgery.

Comparison of Modified Broström and Evans Procedures in Simulated Lateral Ankle Injury

PURPOSE

The purpose of this study was to compare the modified Broström and Evans procedures for simulated lateral ankle instability in cadaveric lower extremities.

METHODS

Six normal cadaveric ankles were loaded with inversion and internal rotation stress through the range of ankle flexion, and three-dimensional motion of the calcaneus and talus relative to the tibia were measured. An ankle stability testing device and a magnetic tracking system were used. Testing was performed in the intact condition, unstable condition after sectioning both the anterior talofibular (ATFL) and calcaneofibular ligaments (CFL), after the Gould modification of the Broström procedure, and after the Evans procedure.

RESULTS

With inversion loading, both operations resulted in a significantly more stable ankle-hindfoot complex (calcaneal-tibial) than the unstable condition, but there was restricted motion after the Evans operation from neutral to plantarflexion. Tibiotalar inversion motion approximated normal after both operations, but subtalar motion was markedly restricted in the Evans procedure throughout the range of ankle flexion. With internal rotation loading, the Broström operation stabilized the ankle-hindfoot joint complex in plantarflexion. The Evans operation improved internal rotation stability, but restricted motion in all positions. Both operations improved tibiotalar internal rotation stability, but not to normal. The subtalar internal rotation was the same as the intact condition after the Broström operation, but markedly restricted after the Evans operation through the range of ankle flexion.

CONCLUSIONS

Both operations improved ankle-hindfoot stability, but neither was successful in restoring it to normal as determined with the ankle stability testing device. The Evans procedure improved stability at the expense of creating abnormal subtalar function. The Broström operation improved stability without excessively restricting subtalar movement, but was not effective in addressing the internal rotation laxity.

Midterm results of a modified evans repair for chronic lateral ankle instability

Twenty-eight ankles in 27 patients with chronic instability were treated with a modification of the Evans procedure during a 10-year period. The diagnosis was assessed by clinical evaluation and radiographic stress tests. The reconstruction procedure consists of using the peroneal brevis tendon to repair ankle instability and restore the loss of anatomic integrity of the injured structures. Twenty-five patients (26 ankles) were available at a mean followup of 99.6 months or 8.3 years (range, 28-117 months). Midterm results were evaluated using the ankle-hindfoot score of the American Orthopaedic Foot and Ankle Society, and postoperative radiographic stress tests. According to this scoring system, the current reconstruction procedure resulted in 92.64 points (range, 63-100 points). However, moderate restriction in hindfoot inversion was seen in nine patients (34.61%). Three ankles (11.5%) had a positive anterior drawer sign (> 8 mm). In five ankles (19.2%), there were mild degenerative joint changes. Therefore, the current reconstruction method led to a satisfactory clinical and functional midterm outcome shown by a numeric scale.

Elongation behavior of calcaneofibular and cervical ligaments in a closed kinetic chain: pathomechanics of lateral hindfoot instability

Numerous reconstructive procedures are performed to correct both ankle and subtalar instability after trauma although the precise pathology which results in this chronic instability and pain is not yet known. This study examined the role of the calcaneofibular (CLFL) and cervical ligaments (CRVL) during physiologic loading and demonstrated the effect of CLFL deficiency on the CRVL. Talar and subtalar tilt as well as inversion range of motion before and after CLFL sectioning were studied. Eleven osteoligamentous fresh frozen cadaver legs were used in which each foot was taken through six positions: neutral, 35 degrees plantarflexion, dorsiflexion, inversion, plantarflexion-inversion, and dorsiflexion-inversion. The CLFL and CRVL stretched the greatest in dorsiflexion-inversion. The most interesting finding was that the CRVL was elongated relative to neutral in all other test positions of the foot. However, the CLFL was shortened relative to neutral in plantarflexion and plantarflexion-inversion. In the CLFL deficient state, CRVL ratios demonstrated significant increases in length of the CRVL. Talar tilt increased on average more than 9 degrees with CLFL deficiency (p < 0.008) while subtalar tilt did not change significantly. The maximum tibiocalcaneal angle, recorded for dorsiflexion-inversion, increased more than 5 degrees after sectioning the CLFL (p < 0.05).

Arthroscopic findings in patients with chronic ankle instability

BACKGROUND

There are little objective data on structural changes of the chronically unstable ankle. Such knowledge could help with preoperative planning.

HYPOTHESIS

Preoperative ankle arthroscopy provides important insights into the causes and mechanisms of ankle instability and the resulting disability.

STUDY DESIGN

Case series.

METHODS

From 1993 to 1999, arthroscopic examination was performed in the ankles of 148 patients with symptomatic chronic ankle instability that had lasted 6 months or more. All structural changes were recorded and compared with the clinical diagnosis.

RESULTS

A rupture or elongation of the anterior talofibular ligament was noted in 86% of ankles, of the calcaneofibular ligament in 64%, and of the deltoid ligament in 40%. Cartilage damage was noted in 66% of ankles with lateral ligament injuries, whereas 98% of the ankles with deltoid ligament injuries had cartilage damage. Although lateral instability could be verified arthroscopically in 127 patients, medial instability was presumed clinically in 38 patients but was actually detected in 54 patients arthroscopically.

CONCLUSION

Preoperative ankle arthroscopy revealed an essential amount of information that would otherwise have been undetected. For instance, the ligaments showed typical abnormalities corresponding to different entities of ankle instability and different intraarticular pathologic conditions.

Biomechanics of the unstable ankle joint and clinical implications

PURPOSE

The aim of this paper is to provide fundamental information about the biomechanics of the unstable ankle joint and to establish a rational for the daily clinic when dealing with patients in both, the acute and chronic unstable condition of the ankle joint complex.

METHODS

The problem of the unstable ankle joint is worked up by analyses of the basic anatomy and biomechanics followed by an overview of its clinical manifestation including a differential diagnosis.

RESULTS

The ankle joint and its surrounding ligaments represent a complex mechanical structure whose mechanical properties highly depend on ligament integrity. Recent in vitro studies have supported the hypothesis that, besides maintaining lateral ankle stability, the lateral ankle ligaments play a significant role in maintaining rotational ankle stability and in transferring movement between leg and foot. Instability of the ankle results from acute ligament injuries and may become chronic when complete ligament healing does not occur. Chronic instability syndrome may manifest with recurrent injuries with chronic lateral pain, tenderness, swelling, or induration with great difficulties in sports and daily activities. Symptomatic instability can be caused by mechanical instability with demonstrable instability, but it can be also present with no demonstrable instability. Impairment of ankle proprioception has been shown to be a major cause of symptomatic ankle instability. Other conditions may mimic ankle instability.

CONCLUSIONS

The cause of chronic functional instability is often not mechanical instability but impairment of ankle proprioception. A history of insecurity, instability, and giving way is far more important in diagnosis than the physical and radiographic examination. If surgical treatment is advised, anatomical reconstruction of the ankle ligaments is mandatory for fear of altering the biomechanics.

Elongation behavior of calcaneofibular and cervical ligaments during inversion loads applied in an open kinetic chain

The cervical ligament plays a significant role in lateral stability of the subtalar joint but has received little attention compared with other ankle and subtalar joint ligaments. The purpose of this research was twofold. First, the elongation behavior of the cervical ligament was assessed with the calcaneofibular ligament intact and cut during two different types of inversion loads (manual and mechanical). Second, inversion range of motion was determined concomitantly with inversion loading and the difference in inversion range of motion between the calcaneofibular ligament intact to cut state was compared. The mean elongation of the cervical ligament with the calcaneofibular intact was 0.58 mm (+/- 0.33 mm) and 0.46 mm (+/- 0.23 mm) for manual and mechanical methods, respectively, and 0.88 mm (+/- 0.37 mm) and 0.78 mm (+/- 0.37 mm), respectively, for the same methods in the absence of the calcaneofibular ligament. This difference was statistically significant (P < 0.05 manually and P < 0.02 mechanically). An average increase in the inversion range of motion was noted with both methods [7.5 degrees manually (+/- 2.75 degrees) and 7.7 degrees mechanically (+/- 2.95 degrees)] after lesioning of the calcaneofibular ligament. This difference was statistically significant (P < 0.001) for both manual and mechanical range of motion testing. The results of this study indicate that there is a significant increase in elongation of the cervical ligament in the absence of the calcaneofibular ligament during manual and mechanically applied inversion loads in a open kinetic chain. Clinical and theoretical implications of this data are discussed.

Functional evaluation of the 10-year outcome after modified Evans repair for chronic ankle instability

The Evans tenodesis is an operative treatment for chronic ankle instability with good short-term results. The disadvantage of impaired hind foot kinematics and restricted motion has been described, and only few reports of long-term results can be found. No techniques have been used to assess the outcome objectively. We wanted to determine whether a modified Evans procedure led to a satisfactory clinical and functional outcome. Nineteen patients were available at a 10-year follow-up. The clinical examination included a detailed questionnaire and stress radiographs. Foot function was evaluated with plantar pressure distribution measurements during walking and peroneal reaction time measurements elicited on a rapidly tilting platform (recorded with surface electromyography). High subjective patient satisfaction was contrasted with a high rate of residual instability, pain, and swelling. The radiographs showed an increased number of exostoses. The gait analysis revealed reduced peak pressures under the lateral heel and increased values under the longitudinal arch. The reaction times of the peroneal muscles were shorter on the operated side (significant: peroneus longus). The persistent clinical problems as well as the functional changes indicate that the disturbed ankle joint kinematics permanently alter foot function and may subsequently support the development of arthrosis. Therefore, the Evans procedure should only be applied if anatomical reconstruction of the lateral ankle ligaments is not feasible.

Reconstruction of the lateral ankle ligaments using an inferior extensor retinaculum flap

The aim of this study was to assess the results of 32 cases of chronic ankle instability. These were treated by ligament shortening and reinforced with an inferior extensor retinaculum flap. All patients complained of persistent functional instability unrelieved with proprioceptive exercises. Results were assessed clinically (pain, instability, recovery of sports activity, mobility) and radiologically (correction of laxity on stress x-rays). This enabled us to draw up a revision score on a scale of 100 points. We obtained a mean score of 86.7 points (45-100 points), and subjective results showed that 88% of the patients were satisfied with the surgery.

Acute repair and delayed reconstruction for lateral ankle instability: twenty-year follow-up study

OBJECTIVES

To determine long-term results of patients who underwent primary ligament repair and delayed reconstruction for lateral ligament instability.

DESIGN

Retrospective.

SETTING

Outpatient clinic.

PATIENTS/PARTICIPANTS

Patients who had undergone acute repair or delayed reconstruction at this institution between 1958 and 1977, excluding patients who were deceased or who could not be located.

INTERVENTION

Forty-eight patients (fifty-three ankles) underwent twenty-two primary ligament repairs and thirty-one delayed reconstruction operations.

MAIN OUTCOME MEASUREMENTS

Clinical results graded with clinical scale and radiologic results based on stress radiographs and plain film radiographs.

RESULTS

At an average of twenty years after operation (range 12 to 33 years), patients were satisfied with forty-nine ankles, satisfied with reservations with two ankles, and dissatisfied with two ankles. Clinical results after repair were excellent in twenty ankles, good in one, fair in none, and poor in one. After reconstruction, the results were excellent in twenty-one ankles, good in six, fair in one, and poor in three. In the primary repair group, the mean talar tilt with stress testing improved from 20.7 +/- 10.7 degrees before operation to 2.8 +/- 3.0 degrees after operation. In the reconstruction group, the mean talar tilt improved from 20.7 +/- 8.4 degrees before operation to 2.8 +/- 3.5 degrees after operation.

CONCLUSIONS

Clinical and radiologic results were similar in the repair and reconstruction groups. The majority of severe (Grade III) ankle sprains may be treated nonoperatively, but if residual instability occurs, late reconstruction should achieve satisfactory results.

Changes in the flexibility characteristics of the ankle complex due to damage to the lateral collateral ligaments: an in vitro and in vivo study

This study was part of a long-term effort to develop a reliable diagnostic procedure for ankle ligament injuries. Earlier efforts led to the development and validation of a six-degrees-of-freedom instrumented linkage capable of measuring the flexibility characteristics of the ankle complex in vitro and in vivo. The major goal of the present study was to determine if these flexibility measurements are sufficiently sensitive to detect the presence of damage to the lateral collateral ligaments of the ankle joint both in vitro and in vivo. The in vitro testing was conducted on the legs from six fresh cadavers before and after serial sectioning of the anterior talofibular ligament and the calcaneofibular ligament. The flexibility in inversion-eversion, anterior drawer, and internal-external rotation was measured before and after resection of the ligaments. The in vivo testing was conducted on five patients with unilateral injuries to the ankle ligament. The flexibility evaluation used for in vitro specimens was also performed on both the injured and the intact ankles. For the in vitro testing, the data analysis was based on comparison of flexibility values before and after resection of the ligaments, whereas the data analysis for the in vivo testing was based on comparison of the flexibility of the injured joint with that of the intact contralateral joint. The results of the in vitro study indicated that both an isolated rupture of the anterior talofibular ligament and combined damage of the anterior talofibular and calcaneofibular ligaments produce statistically significant changes in flexibility. Furthermore, the most sensitive parameters to the presence of ligament injuries were found to be early flexibility in anterior drawer, early flexibility in inversion, and the amount of coupling between internal rotation and inversion. These parameters provided a basis for differentiating between an isolated injury to the anterior talofibular ligament and a combined anterior talofibular and calcaneofibular ligament injury. For an isolated anterior talofibular ligament injury, a significant increase in flexibility in anterior drawer was present, whereas the increase in inversion flexibility or in the amount of coupling was insignificant. However, the increases in inversion flexibility and the amount of coupling became significant when both ligaments were involved. The results of the in vivo study indicated that significant changes in flexibility can be detected in patients with lateral ankle injuries. Finally, both the in vitro and in vivo results suggest that development of a reliable diagnostic test for ankle ligament injury based on changes in passive flexibility may be possible.

NOVEL Award 1996: 2nd prize Tenodeses do not fully restore ankle joint loading characteristics: a biomechanical in vitro investigation in the hind foot

OBJECTIVE: In order to understand the biomechanical consequences of ligament injuries and surgical reconstruction procedures, their effects on intra-articular loading in the ankle joint complex and Chopart joint line and on the plantar pressure patterns were investigated in vitro. METHODS: Twelve fresh-frozen lower leg specimens were freed of soft tissue down to the malleoli and prepared for accessing the talocrural, subtalar, talonavicular and calcaneocuboid joints. The specimens were fixed in a loading simulator and axially loaded with 600 N in six experimental conditions: intact; after cutting the anterior talofibular ligament; after additionally cutting the calcaneofibular ligament; after performing three common types of tenodeses, the Evans, Watson-Jones and Chrisman-Snook procedures. The intra-articular loading characteristics were determined with pressure sensitive film. Plantar loading patterns were measured with a capacitive EMED pressure distribution platform. RESULTS: Average intra-articular pressures were increased and were related either to decreased contact areas or to increased contact forces found in all joints after ligament resections and tenodeses. Plantar loading was increased under the medial aspect of the foot and decreased under the midfoot region. CONCLUSIONS: The results indicate that ankle ligament injuries, as well as surgical reconstructions by tenodeses, affect joint loading characteristics and may exacerbate joint degeneration. RELEVANCE: Excessive laxity of the ankle joint is considered a pre-arthrotic condition and is treated with various surgical procedures. Some of these procedures that utilize the tendon of the peroneus brevis have been shown to change joint kinematics. The aim was to evaluate joint loading characteristics and the potential danger of developing arthritis as a consequence of various tenodeses techniques. For this purpose, in vitro investigations are needed to directly determine intra-articular pressure measurements.

Chronic lateral ankle instability

Chronic lateral ankle instability may be present in as many as 10% to 30% of people suffering from acute lateral ankle ligament injuries. Ankle instability has been referred to as either functional instability or mechanical instability. Management options consist of either nonoperative or operative treatment, with the majority of the literature emphasizing operative management for chronic instability. Long-term studies assessing the different types of available operative repairs have now been published. This review article discusses chronic lateral ankle ligament instability from a functional, anatomical point of view. The indications for treatment, nonoperative and operative treatment, as well as the biomechanical information available regarding these methods of treatment are considered. The major emphasis of this review is discussion and analysis of the many different surgical treatment options. Following this review, we presently recommend anatomical repair to the bone of both the anterior talofibular ligament and the calcaneofibular ligament, together with imbrication of the ligaments. In patients with hypermobility, long-standing instability, or arthritis, reconstruction using the Chrisman-Snook technique is recommended.

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.

The Ottosson repair in lateral instability of the ankle

A follow-up study is presented of 27 patients with 29 ankles treated for disabling lateral instability by a modification of the Evans repair, previously described by Ottosson. The median follow-up period was 39 months. Excellent or good results were found in 93% of the ankles. We recommend this modification, as it is technically simple and efficient.

Evans' procedure in the treatment of chronic instability of the ankle

During the period 1979-1983, 34 patients were treated for chronic instability of the ankle which was confirmed by stress radiography, using Evans' procedure. Of the injuries, 65 per cent were sustained at sport. A feeling of instability was the main presenting symptom (85 per cent). All the patients were examined clinically and with stress radiography at follow-up. The results were regarded as good in 27 cases (80 per cent), fair in five (14 per cent) and poor in two cases. None of the patients found the limitation of subtalar inversion disturbing. In the radiographic examination using a Cheuba stress-producing device, the magnitude of anterior drawer instability as well as the talar tilt was significantly reduced (P less than 0.001).

Treatment of lateral instability of the ankle--a new modification of the Evans repair

A modification of the Evans repair using only half of the peroneus brevis tendon was applied in the treatment of 34 patients with chronic functional lateral instability of the ankle. With a median follow-up of 25 months, 32 patients were examined. Functional stability was achieved in all but one patient. This modification of Evans' repair is recommended, as it is technically easy, gives good functional stability, and has the theoretical advantage of saving an important pronator of the foot.

Radiographic instability of the ankle joint after Evans' repair

Forty-two unstable ankle joints were treated surgically by Evans' operation. The clinical postoperative results were correlated with the objective radiological stress examinations. The mean age of the patients was 29 years (15-60 years). The clinical and radiological follow-up examinations were performed 6 months after the operation. In the stress X-ray examinations a modified stress frame was used. Clinical instability was noted in four patients. In the radiological examination one patient had a pathological finding in the talar tilt test and 18 patients in the anterior drawer sign test. The radiological instability correlated poorly with the subjective end results. Six patients were estimated to have a poor result of the operation. Five of these patients had a positive anterior drawer sign in the stress X-ray examination and one had degenerative changes in the ankle. Although Evans' repair is a simple and reliable method of reconstructing ruptures of the lateral ligaments of the ankle joint, it is associated with a relatively high frequency of positive anterior subluxation on radiological stress examination. This finding can be explained by the anatomical and geometrical factors on the lateral side of the ankle joint.