The ankle is a commonly injured joint in many sports (it has been estimated there are 5000 ankle sprains a day in the UK!) but perhaps receives less attention than the knee, as injuries tend to be less dramatic and functional instability following ligament sprains is uncommon – there are few problems that are potentially career threatening. Morbidity following injury is common however, and can certainly take the edge off elite performance. In the older professional, adaptive changes can start to interfere with activity by causing stiffness or impingement, often precipitating surgical intervention.
Ankle Ligament Injuries
The ankle derives stability in a neutral position from its’ bony architecture, the joint structure producing 100% of the restraint to inversion. As the ankle starts to plantar flex, the restraint to inversion is increasingly provided by the ligaments – the explanation for why the majority of ligament injuries occur during take off or landing, when the ankle is naturally in a plantar flexed position.
Unlike the knee, where a rotational instability following ACL injury cannot be compensated for by muscle recruitment, the dynamic stabilisers of the ankle can generally be retrained to cope with loss of ligamentous stability, reducing the need for surgical reconstruction to only a very small percentage of the total number of injuries.
The ankle ligaments can be divided into three groups – the lateral complex, the medial complex and the distal tibiofibular syndesmosis. The lateral complex is composed of the anterior talofibular (ATFL), the calcaneofibular (CFL) and the posterior talofibular (PTFL) ligaments.
The ATFL is the primary restraint to inversion, anterior translation of the talus and internal rotation and is the most commonly injured. The calcaneofibular ligament comes under greatest strain as inversion is applied and the ankle moves into dorsiflexion. If ankle ligament injury occurs in plantar flexion the ATFL is the first to be torn, but if the force continues the CFL is injured next and then the PTFL. If the ankle is inverted in neutral the CFL is most at risk and in dorsiflexion a syndesmosis injury is most likely to occur (1).
The medial ligament consists of deep and superficial layers of the deltoid ligament. It is rarely injured. In 10 years of practice I have seen only one significant injury to this ligament, in a professional footballer who had a coexistent tarsal coalition with gross pronation of the foot, and with an eversion injury completely avulsed the medial complex from the medial malleolus. Following anatomical repair he is still playing five years later.
The syndesmotic ligaments consist of anterior and posterior inferior tibiofibular ligaments and the interosseous ligaments. Strain in these ligaments increase with dorsiflexion and external rotation.
The diagnosis of acute lateral ligament injuries presents no real difficulty but it is important to take an accurate history of the exact mechanism of injury to identify the likely injured components. There has been a large variation in approach to the management of this injury, but the concensus is that early functional treatment is the best (2,3), providing a quicker return to normal and sporting activity and minimal morbidity. The one method of treatment that has been shown to produce the worst result is plaster immobilisation – a treatment that still seems to be popular in the UK today!
Following early functional treatment, including weightbearing as pain allows, one can generally expect return to sport in around six to eight weeks although sometimes with the more severe injuries, recovery can take up to 12 weeks.
If recovery is not progressing satisfactorily there are a number of conditions that can cause persistent pain following inversion sprains. This is the so called “6 pack” of diagnoses described by Ogilvie-Harris:-
1. The instabilities (Lateral and Syndesmotic)
2. Impingement (anterior and anterolateral)
3. Chondral and Osteochondral lesions.
Investigation may require a number of radiographic techniques but the end result is usually ankle arthroscopy! The results of ankle arthroscopic intervention for these conditions are generally good but are prejudiced by the presence of a coexistent ankle instability.
Chronic ankle instability with recurrent inversion sprains also presents little diagnostic difficulty. A clinically positive anterior drawer test can be confirmed by stress radiography. Again, most patients will improve with a course of appropriate physiotherapy but those who remain symptomatic may elect for surgical reconstruction.
The current surgical reconstruction method of choice is the Brostrom repair, essentially a double breasting of the remains of the ATFL. It sacrifices no normal tissue and produces little restriction of normal range of movement (4,5). It is always necessary to inspect the CFL and certainly in my experience this is often avulsed from its fibula attachment but remains intact and can be reattached to its anatomical origin through a couple of drill holes in the fibula. Return to sport can usually be made at around 10 weeks post op.
Syndesmotic tears are not uncommon if football as the mechanism of injury of plantar flexion and external rotation. These tears are usually partial and cause anterolateral pain. Clinically two tests are useful in identifying the problem. The squeeze test when the fibular is compressed against the tibia at mid calf level may elicit pain but I have found more useful to stand the patient on the affected ankle and ask them to turn laterally externally rotating the lower leg on the ankle. If there is failure to respond to conservative management then ankle arthroscopy and resection of torn segments of ligament (which often hang down into the joint and cause impingement) produces satisfactory results (6).
Soft tissue impingement may occur following injury. This may be from torn ligament as outlined above or from chronic synovial hypertrophy, where swollen synovium gets trapped during ankle movement causing further trauma and setting up a vicious circle of swelling and further trauma. This thickening and hypertrophy may produce so called meniscoid lesions in the anterolateral aspect of the joint (7). Another cause of anterolateral impingement following inversion sprain is thickening and hypertrophy of the inferior slip of the anterior tibiofibular ligament – the so called Bassett ligament (8). Arthroscopic resection of all these lesions this will provide relief of symptoms.
Bony impingement mainly occurs either anteriorly or posteriorly. Anteriorly it is almost invariably a distal tibial osteophyte which causes impingement in dorsiflexion and restricting range of movement and is common in aging (30 years plus!) footballers and rugby players. On examination there is a solid block to dorsiflexion and the X-ray appearances are obvious. It is often said to be a traction phenomenon but the osteophyte is intracapsular enabling a fairly straightforward arthroscopic resection (9). This generally results in a rapid improvement in range of movement and symptoms and although the osteophytes tend to recur, this small procedure can prolong the playing career of a professional by several seasons.
Posterior impingement is a condition rarely seen in the non sporting population but occurs in sportsmen and women whose activities involve extreme plantar flexion of the ankle such as footballers, gymnasts and especially dancers. The impingement usually occurs between an os trigonum and the posterior aspect of the tibia. Clinically this can be reproduced by lying the patient prone with the knee flexed to 90 degrees, grasping the heel, forcibly plantar flexing the foot and then rocking the heel medially and laterally – this invariably reproduces the symptoms! A plain lateral x-ray in maximum plantar flexion will highlight the problem and a bone scan will be hot.
If there is an os trigonum rather than a large lateral tubercle, it is possible to put a steroid injection into the pseudojoint between the os-trigonum and talus under radiographic control and this will often settle the symptoms down, certainly in the short term. If symptoms don’t settle or recur, then surgical excision, these days via a hindfoot endoscopy, of the os-trigonum produces satisfactory results (10).
Soft tissue posterior impingement can occur following an inversion sprain in neutral when the posterior talo-fibular/tibiofibular ligaments are at risk. A mass effect produces persitent posterior impingement. Symptoms include difficulty in sprinting and striking a ball. Ultrasound guided injection can often settle the problem down.
Chondral and Osteochondral Lesions
Persistent pain following ankle sprain is often associated with injury to the chondral surface or an Osteochondral talar dome fracture. Stage1 and 2 osteochondral lesions may not be seen on plain x-rays, and isotope bone scanning is a useful screening procedure followed by MRI if the scan is positive (11). If the fracture is visible on plain x-ray CT is adequate to delineate the lesion.
Treatment is by arthroscopic removal of the fragment and drilling. Even quite large lesions will respond to this treatment and allow return to sport. It is presumably the congruence of the ankle joint that allows this, by avoiding the point loading that occurs in the knee where this type of problem is generally more problematic.
Diagnostic difficulty arises with Chondral lesion for which at the present time we have no way of radiologically identifying or defining the lesions. The diagnosis remains essentially clinical and arthroscopy remains the only way of confirming the problem when a variety of patterns of injury may be seen (12). It does however mean that treatment of unstable cartilage lesion can be carried out at the same time with a generally good prognosis.
Around the ankle the commonest tendon injuries tend to be chronic rather than acute and are often badly managed in their early stages when there is the best chance of getting them to heal.
One of the more common acute injuries that I have seen, is dislocation of the peroneal tendons. This is frequently missed in the initial stages and leads to recurrent subluxation of the tendons over the back of the lateral malleolus leading to repeated giving way episodes. The patient often feels a pop or snap associated with the subluxation and in very chronic cases can reproduce the subluxation for you. Conservative treatment is generally of little help but surgery, with deepening of the peroneal groove as described by Zoellner and Clancy, has satisfactory results (13)
Of the chronic tendon problems the most common, and often most difficult to treat, is Achilles tendonitis. The cause is usually an error in training, most commonly a sudden acceleration in training intensity or sudden introduction of hill training. As in any tendon in the body, the Achilles tendon has relatively poor vascularity and so adjusts to new loading patterns quite slowly. Also, failure tends to occur during eccentric loading, and training to cope with this type of loading is often poorly understood or badly carried out. Any training regime in sports involving jumping, sudden acceleration or deceleration or running up and down hills should incorporate and eccentric strengthening programme in their fitness training.
The other major contributor to Achilles tendon injury is a lack of flexibility, particularly as the athlete starts to age and tissues become less pliable. A common error is only to stretch gastrocnemius and not soleus and it is the soleus component of the Achilles tendon that is most often the problem.
Biomechanics may also contribute with excessive pronation of the forefoot producing an excessive “whip” in the Achilles and predisposing to injury generally in the posteromedial aspect of the tendon.
Local factors may also produce injury. For many years boots and training shoes would have “Achilles protectors” in the form of a large tab at the back of the boot. As the foot plantar flexed this would be driven into the back of the Achilles in its least vascular part. It is always worth inspecting footwear in any sportsperson with ankle or heel problems.
Athletes should be taught to recognise the early signs of tendonitis – a soreness that persists for a couple of hours of exercise. If it is recognised, easing back on a training schedule until symptoms have gone and then progressing forward again will produce resolution. Unfortunately the “no pain no gain” type of approach is common in many sports and to push through excruciating pain is seen as a “badge of honour”. This of course will produce progressive symptoms that may terminate in rupture.
Management of tendonitis consists of identifying and correcting biomechanical problems and training errors, removing any local factors, and physiotherapy with stretching and eccentric retraining (14). This will generally produce a slow and steady improvement.
Ultrasound scanning is good at identifying problems within the tendon and has a better resolution than MRI. Surgery is reserved for chronic cases not responding to conservative measures when scarification and excision of torn areas and areas of mucoid degeneration followed by a programme as outlined above may return a player to his career. As these problems tend to affect the older athlete however, the development of this problem is often career ending.
Ankle injuries during athletic activity are common and are often badly managed. It behoves us all to be aware of the problems that can occur following ankle sprain and not to dismiss continuing symptoms or even worse inject the joint with “wondermedrone” without having established the underlying cause. Ankle problems in sport generally respond well once a correct diagnosis has been made and appropriate treatment carried out, with resolution of symptoms and return to sporting activity, even at the very highest level.
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