SEQUELAE AFTER FRACTURE OF THE LATERAL PROCESS OF THE TALUS

Abstract

Purpose: The purpose of this study was to: 1) analyse sequelae after fracture of the lateral process of the talus (deformed callus or nonunion) in six patients included five who were operated, the impact on the talocrural and subtalar joint, and treatments that can be proposed and expected results; 2) emphasise the fact that this lesion is not often recognised in its initial stage, leading to late diagnosis despite the better results obtained with early treatment.

Material and methods: Six patients were seen at consultation at the sequelar stage. There were six men, mean age 40 year (20–60); three were high-level athletes. The injury was cause by fall from a high level, two accidents leading to multiple injuries with an unanalysable mechanism, and ankle “sprain” in one patient. Delay to therapeutic management was four months to ten years (mean two years). Pain and joint stiffeness involving the talocrural joints and/or subtalar joints were the predominant signs. The deformed calluses involved the subtalar joint in five cases with one case of nonunion. Five of the patients had been treated surgically: four resections, one screw fixation of the nonunion, and one patient desired surgery. In all the operated cases, pain had disappeared almost entirely but the amplitude of the joints was not totally recovered.

Discussion: Two aspects are particularly important. first fractures of the lateral process of the talus must be considered globally. Frequency has been estimated at 1% of all ankle trauma, certainly an underestimation since these fractures often go unrecognised in the early stages and are too often confused with ankle sprains. Incidence is also increasing with the practise of snow boarding where this injury occurs in 15% of all ankle traumas. The injury results from distraction via the talocalaneal ligaments in an inversion trauma or by compression during dorsiflexion and pronation. Clinical diagnosis is difficult and plain x-rays poorly visualise the lesion, irrespective of the anatomic type (MacCrory classification). CT scan is required to obtain an exact analysis of the fracture and its displacement, necessary for correct treatment: simple immobilisation if there is no displacement or resection of the fragment or osteosynthesis depending on the size of the fragment. Secondly, the pathology of this injury is important to recall: deformed callus or nonunion. The volume of the lesion and its site explain the observed impact, but in all cases, the injury involves the talocruaral joint (painful impingement of the fibular ligament) and talar disorganisation (pain, stiffness or osteoarthritis at the later stages). Depending on the case, treatment consists in excision of the deformed callus, fixation of the nonunion and, for cases seen late, subtalar arthrodesis. An improvment in pain can be achieved but there is almost always loss of joint amplitude.

Conclusion: Whatever treatment is used, the results at the sequelar stage are never excellent. Only early diagnosis with a rigorous clinical examination and adapted imaging (CT scan) can lead to coherent early treatment which provides the best result.