Description of the condition
The foot has a complex mechanical structure with 26 bones, 33 joints and over 100 muscles, tendons and ligaments. Traditionally, it has been divided into the hindfoot or heel (bones: talus, calcaneus), midfoot (bones forming the arch of the foot: cuboid, navicular and 3 cuneiforms) and forefoot (bones: 5 metatarsals and 14 phalanges) (Kelikian 2011).
The forefoot is connected to the midfoot through the tarsometatarsal joint complex; also called the Lisfranc joint complex after Jacques Lisfranc, a surgeon in Napoleon’s army (Lisfranc 1815). Stability and proper alignment of this joint complex are crucial for normal foot function and normal gait (Peicha 2002; Castro 2010). This stability is provided by bony and specialised ligamentous and tendon structures (dorsal, planter, and interosseous ligaments, insertions of the fibularis longus, tibialis anterior and tibialis posterior tendons, intrinsic muscles and plantar fascia) (De Palma 1997).
Of particular importance is the transverse (sideways) stability of the tarsometatarsal joint complex. Structurally, this is assisted by the positioning of the bones and the shape of the bases (upper ends) of the metatarsals and their corresponding cuneiform-cuboid articulations (joint surfaces) (Hardcastle 1982; Lu 1997; Kura 2001). While the third, fourth and fifth metatarsals are connected by intertarsal ligaments, transverse stability of the first and second metatarsals is only provided by the Lisfranc ligament, which extends obliquely from first cuneiform to the base of the second metatarsal. This ligament is of paramount importance for the stability of the tarsometatarsal joint complex (Preidler 1996; Solan 2001; Thompson 2003).
Injury to the tarsometatarsal joint complex can range from a mild sprain or subtle subluxations (partial dislocation) to significantly displaced and debilitating injuries (Myerson 1989). It was first described by Lisfranc in 1815 from his experience treating of injured cavalry men in the Napoleonic wars (Lisfranc 1815; Fischer 2005). He described how soldiers fell off their horses with their forefeet trapped in the stirrups, sustaining fracture dislocations to their midfeet (Esway 2006).
The mechanism of injury can be broadly classified as direct or indirect (Vuori 1993). A direct injury occurs when an external force, such as from the impact of a heavy object, is applied directly to the midfoot. This may result in displacement of the metatarsal bases, and is often associated with severe soft tissue damage (Thompson 2003; Smith 2005).
Indirect injury is more common and is often the result of a force applied to a downward-flexed foot, where the weight of the body act as a deforming force. Such injuries have been reported in high-energy motor vehicle or motorcycle accidents, falls from a height or down stairs and, as witnessed by Lisfranc, a fall from a horse with the forefoot held in a stirrup. Less severe injuries have also been reported in tackled football players, with windsurfing and snowboarding injuries (Myerson 2008), and even following a simple trip while jogging (Wright 2013)
Lisfranc injuries account for approximately 0.2% of all fractures with an incidence of 1/55,000 cases per year (Richter 2001; Desmond 2006). However, the incidence of these injuries appears to have been increasing over the last two decades, particularly since the introduction and routine use of airbags in motor vehicles (Smith 2005). People who previously might not have survived, now sustain severe blunt trauma to their lower extremities and feet, often resulting in dislocations of the midfoot and hindfoot (Loo 1996; Siegel 2001).
Accurate diagnosis of Lisfranc injuries can be difficult, and misdiagnosis or a delayed diagnosis occurs in up to 20% of cases, particularly in the subtle ligamentous injuries and subluxations (Kuo 2000; Lattermann 2007; Hatem 2008). Evaluation typically begins with clinical history and plain radiographs of the foot; however, because of overlapping bony structures on routine radiographic views, fractures can be easily missed and ligamentous injuries overlooked. Stress views or weight-bearing radiographs, computed tomography (CT) or magnetic resonance imaging (MRI) are often required in inconclusive cases (Preidler 1999; Rand 2000).
Quenu and Kuss first classified these injuries as homolateral, isolated or divergent based on the direction of the displaced metatarsals (Quenu 1909). Hardcastle 1982 modified the original classification into type A, B or C based on the degree of displacement and incongruity of the tarsometatarsal joints. This was further modified by Myerson 1986 adding subtypes and more proximal injures, acknowledging, however, that the outcomes and treatment did not correlate reliably with any injury type (see Appendix 1). To address the more subtle, mainly ligamentous, low-energy injuries seen in athletes, Nunley 2002 devised a classification system based on weight-bearing radiographs and bone scintigraphy (see Appendix 2).
Complications of injuries to the tarsometatarsal joint complex can be devastating; for example, post-traumatic arthritis and severe chronic foot pain. Whilst management strategies for treating these injuries lack consensus in the literature, there is agreement that early diagnosis and prompt treatment improve the final functional outcome (Mulier 2002; Ly 2006; Myerson 2008; Henning 2009; Stavlas 2010).
Description of the intervention
Non-surgical management with cast immobilisation is only recommended for non-displaced injuries (Pylawka 2008). Injuries with any degree of displacement are treated surgically, aiming for anatomical reduction and prevention of further displacement. This can be achieved through surgical fixation or fusion. There are three main methods: closed reduction and percutaneous fixation, open reduction and internal fixation (ORIF), and arthrodesis, performed as a primary intervention.
Closed reduction and percutaneous fixation
This comprises closed reduction (reduction by manipulation of bone through the skin) and the use of percutaneous (through the skin) Kirschner wires or cannulated screws to hold the reduction. Use of this method has been reported for simple tarsometatarsal fractures.
Open reduction and internal fixation (ORIF)
Open reduction (manipulation of bone after surgical exposure of the fracture) and internal fixation is considered the standard treatment for most Lisfranc injuries (Arntz 1988; Pérez Blanco 1988; Resch 1990). The techniques of ORIF vary; for example, Kirschner wire fixation, standard AO screw fixation (3.5 mm, 4.5 mm), bioabsorbable polylactide screws (Thordarson 2002) and dorsal plate fixation (Kuo 2000; Stavlas 2010; Scolaro 2011). A combination of techniques has often been used, particularly Kirschner wires fixation across the more mobile 4th and 5th tarsometatarsal joints and rigid screw fixation across the medial 1st, 2nd and 3rd joints (Arntz 1988).
Primary (initial procedure) arthrodesis (or fusion) of the midfoot involves fusing or stiffening the tarsometatarsal joint complex using pins, plates and screws so that the damaged bones heal into one continuous piece of bone. This procedure has been traditionally reserved as a salvage procedure for severely comminuted fractures and gross instabilities that have been considered at significantly high risk of post-traumatic arthritis.
Following surgery, the foot is generally placed in a well-padded dressing with a plaster around the foot and lower leg or a removable boot for two weeks, when any sutures are removed. Patients remain non-weight bearing in a short leg cast or boot for an additional 4 to 10 weeks, depending on the injury and surgery. When used, temporary K-wires are typically removed at six weeks or before weight-bearing is allowed, in order to prevent pin breakage.
How the intervention might work
The treatment of tarsometatarsal fracture dislocations has evolved over the years from closed reduction and cast immobilisation to the current standards of open reduction and stable internal fixation with emphasis on anatomic joint restoration. Whilst the outcomes of these injuries have improved slightly over the years, they remain relatively poor and the treatment strategies are likely to continue evolving. The main goal of treatment is to have a functional foot, i.e. a painless, stable, plantigrade foot. This is achieved by restoring and maintaining the anatomical relationships of both bony and ligamentous structures (Alberta 2005; Lattermann 2007; Watson 2010).
Post-traumatic arthritis is the most common complication of tarsometatarsal fracture dislocations, often leading to deep aching midfoot pain aggravated by activity (Sangeorzan 1990; Schepers 2010). Indeed, a key aim of surgical intervention is to reduce the risk of post-traumatic arthritis. However, there is no evidence to correlate the severity of injury, or degree or pattern of displacement with the final functional outcome (Siegel 2001; Teng 2002; Stavlas 2010).
Closed reduction and percutaneous fixation is the least invasive surgical option but lack of direct visualisation of these generally complex injuries means that it is generally considered for simple tarsometatarsal fractures. Generally, closed reduction is considered ineffective in maintaining articular congruity (Myerson 1989; Trevino 1995; Buzzard 1998; Wagner 2013).
Although a more invasive procedure than closed reduction, open reduction and internal fixation (ORIF) facilitate better assessment and manipulation of the dislocated anatomy and more accurate fixation of the reduced parts, included articular fractures. The use of dorsal plates (e.g. one-fourth tubular plate) seems to have the theoretical advantage of rigid fixation without transarticular screws avoiding damage to the articular cartilage (Alberta 2005).
Given it is a more drastic procedure, which substantially alters foot mechanics, primary arthrodesis is typically reserved for more substantial injuries, where there are major questions on whether fixation that restores the anatomy is sufficient for a satisfactory long-term outcome.
Why it is important to do this review
Tarsometatarsal fracture dislocations vary in their severity and can have poor outcomes. There are several different surgical interventions available and in current use. Thus there is a need to inform practice by systematically reviewing the evidence for the use of these different surgical interventions. A recent review comparing primary fusion with internal fixation concluded that these methods were equivalent (Sheibani-Rad 2012). However, to our knowledge, there has been no systematic review of randomised clinical trials that focuses on all surgical treatments of tarsometatarsal (Lisfranc) fracture dislocations in adults.