Radiographic instability of the ankle joint after Evans' repair

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.

Lateral ankle instability and revision surgery alternatives in the athlete

Ankle instability in the athlete is a common problem that is routinely treated non-operatively, with a 90% success rate. With proprioceptive training, preventive equipment (bracing/taping), and closed kinetic chain strengthening, surgery for ankle instability is uncommon. Nonetheless, some athletes present with recurrent ankle instability that, despite work-up and conservative treatment, requires surgical correction. The use of a primary ligament repair (Brostrom procedure) versus augmented (anatomic) reconstructions is discussed in detail in this article.

Operative management of ankle instability: reconstruction with open and percutaneous methods

Chronic ankle instability affects a large number of young patients. A thorough history and clinical examination are key to proper patient selection. Once the patient decides to undergo operative intervention, the appropriate procedure should be selected according to their physical and lifestyle demands. The surgeon should gain familiarity with the full range of procedures, from open to percutaneous, and anatomic to nonanatomic. With proper patient selection, functional outcomes are excellent, with success rates from 80% to 90%.

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.

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.

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.

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).

Complications of lateral ankle ligament reconstruction

Complications after ankle ligament reconstruction are infrequent, but present significant challenges to the treating orthopaedist. Local wound problems and nerve injuries may cause difficulty in the early postoperative period. Recurrent instability may be attributable to failure of the operation, poor rehabilitation, reinjury, or unrecognized predisposing factors. Postoperative stiffness of the subtalar and ankle joints frequently is reported after anatomic and nonanatomic tenodesis procedures and may cause significant morbidity. The current author reviews reported complications and treatment options in failed lateral ankle ligament surgery.

Clinical and functional outcome after anatomic and nonanatomic ankle ligament reconstruction: Evans tenodesis versus periosteal flap

The present study investigated the effects of two different surgical procedures for the treatment of chronic ankle instability. Ten patients treated with an anatomic reconstruction using a periosteal flap were compared with a second group that received an Evans tenodesis. All patients were evaluated before and after surgery with clinical and radiographic examinations as well as dynamic pedobarography. Patient satisfaction and radiographic and functional results were comparable in both groups and revealed a good restoration of joint stability and gait symmetry. Our results indicate that both methods of ankle ligament reconstruction achieve a comparable clinical and functional outcome within 1 year after surgery.

Long-term functional outcome after surgery of chronic ankle instability. A 5-year follow-up study of the modified Evans procedure

Chronic ankle instability is a rather common consequence of poorly healed rupture of the lateral ligaments of the ankle. In some rare cases, instability symptoms can be caused by general laxity of the joints, but since these cases are normally bilateral, they can easily be distinguished from posttraumatic instability. This report presents the long-term (average follow-up 4.6 years) functional outcome after a modified Evans tenodesis of 48 patients. The follow-up examination consisted of a questionnaire evaluating the subjective assessment of the ankle, and clinical examination measuring ankle stability, range of motion and swelling, and atrophy of the calf muscles. Additionally, the functional recovery of the ankle was assessed by a standardized performance test protocol. According to the subjective assessment, 25 subjects (52%) considered the ankle fully recovered, or at least much better than before surgery. In the performance test, however, only 17 subjects (35%) achieved an excellent or good score. In the performance test protocol, two functional tests, walking down a staircase and balancing on a square beam, best demonstrated the impaired function of the injured ankle. The modified Evans procedure could restore the stability of the ankle to the preinjury level, although the ankle range of motion was significantly impaired, and swelling of the ankle and atrophy of the calf muscles were frequent findings at the follow-up. In conclusion, surgical treatment of chronic ankle instability by the Evans procedure restores the mechanical stability of the joint, but too frequently the function of the ankle does not return to the pre-injury level.

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.

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.

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.

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.

Long-term results of the modified Evans repair for chronic ankle instability

We treated 19 patients for chronic ankle instability with a modified Evans procedure. All patients were evaluated after an average follow up of 128 months with detailed questionnaire, clinical examination, and stress radiographs. Although the subjective results were reported as 8 excellent, 7 good, and 4 fair, residual pain was reported by 11 patients. There was a significantly increased number of osteophytes in the treated ankle joint. Stress radiographs demonstrated significantly improved stability in the operated ankle joint. Range of motion was significantly reduced in hindfoot inversion. The results showed that the modified Evans procedure achieved sufficient joint stability at the expense of inversion range of motion. This reconstruction method apparently did not prevent the development of arthrosis.

Gait pattern analysis after ankle ligament reconstruction (modified Evans procedure)

We followed 38 patients with chronic ankle instability treated by a modified Evans procedure. Evaluation at an average of 68 months follow-up included a standard clinical questionnaire and examination, radiological procedures, and gait analysis. Plantar pressure distribution measurements were recorded during walking and were compared with data from a group of normal subjects (N = 100). The subjective patient questionnaire revealed 87% good or excellent results, but residual pain was reported by 40% of the patients. The gait analysis indicated a significant increase in midfoot loading (22%) consistent with an observed restriction of inversion after surgery. However, the plantar pressure changes were not associated with poor clinical outcome. We cannot say whether these increased pressures will be associated with long-term outcome.

Articular cartilage lesions in ankles with lateral ligament injury. An arthroscopic study

To investigate intraarticular lesions producing persistent postoperative pain, we arthroscopically examined 31 ankles in 31 patients (15 women and 16 men) with lateral ligament injury. The patients ranged in age from 15 to 33 years, with a mean of 20 years. Nine patients were freshly injured, and 22 patients had chronic injuries. All of the patients underwent arthroscopic examination immediately before the ligament operation. Chondral lesions were found in 89% of the freshly injured ankles and 95% of the ankles with chronic injuries. Most of these lesions were in the medial half of the ankle joint, especially in the anteromedial edge of the tibial plafond. After followup for 1 year postoperatively, persistent pain was noted in 4 patients who had chondral lesions of greater than one-half the thickness of the articular cartilage. Pain and tenderness were localized at the anteromedial joint line, corresponding to the location of the chondral lesions. Chondral lesions of greater than one-half the thickness of the articular cartilage were found in 8 ankles in the chronic injury group, but there were none in the fresh injury group. Thus, in lateral ligament injuries of the ankle, the longer the time elapsed from the initial injury, the more severe the associated chondral lesions became. These chondral lesions appear to cause persistent pain.

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.

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.