12.61 Fractures of the calcaneum

Calcaneal fractures account for 2% of fractures and 60% of tarsal bone injuries. Since the fracture usually occurs in the working population the economic cost is considerable.

The calcaneum is a box-like structure, squashed from superior to inferior anterior to posterior facet of subtalar joint (PFSTJ) by the sharp crucial angle of Gissane. Posteriorly, the superior surface is bare up to PFSTJ. This is quadrilateral in shape and orientated posteromedial to anterolateral. The bone behind and beneath PFSTJ is termed the tuberosity or body of the calcaneum (Figure 12.61.1A).

Anterior to PFSTJ, the bone is extended anteromedially as the sustentaculum tali (ST), which consists of two thick sheets of cortical bone with the middle facet of subtalar joint (STJ) on its superior surface. Anterior to ST a deep groove, the inter-osseous sulcus, passes laterally terminating as the crucial angle of Gissane, a sharp edge of thick cortical bone into which fits the anterolateral process of talus. The interosseous sulcus forms the inferior surface of the sinus tarsi which gives rise to the interosseous talocalcanean ligament and contains the artery of the sinus tarsi.

In front of the sinus tarsi, the calcaneum narrows. Medially, the superior surface contains the anterior facet of STJ (which may be confluent with the middle facet). It gives origin to three structures from medial to lateral, the bifurcate ligament, which inserts into the adjacent cuboid and navicular bones, the extensor digitorum brevis, and the inferior extensor retinaculum.

The lateral wall of the calcaneum is flat and is mainly thin cortical bone. Immediately anterior to the crucial angle of Gissane, the inferior peroneal retinaculum, through which run the peroneal tendons, is attached to the peroneal tubercle. The posterior calcaneofibular ligament arises from the lateral wall behind and below PFSTJ and immediately anterosuperior to this the capsule of STJ inserts, leaving a bare area posteroinferior to the lateral edge of the joint.

The medial wall is thicker than the lateral and is arched from posteroinferior to anterosuperior with its apex lateral from subcutaneous sustentaculum tali to the medial process inferiorly. The thick cortical sheets of ST are continued anteriorly as a strong anteromedial buttress and fuse with the medial aspect of the calcaneocuboid joint (CCJ).

The medial wall gives origin to the intrinsic muscles of the foot, which separate it from the posterior tibial neurovascular structures. Superiorly, the medial wall is grooved by the flexor hallucis tendon passing beneath ST.

The anterosuperior corner of the medial wall is intimately related to the talus and navicular.

The anterior wall of the calcaneum is the CCJ which is shield shaped with its point inferiorly (Figure 12.61.1B). The superior part of the joint is orientated in an oblique plane from posterolateral to anteromedial, while inferiorly the orientation is anterolateral to posteromedial. In addition, the superior edge lies anterior to the inferior. This complicated geometry makes reduction and fixation of the joint difficult.

The plantar surface of the calcaneum contains the medial and lateral processes, which give origin to the plantar fascia and the small muscles of the plantar aspect of the foot.

The posterior surface of the calcaneum contains the tendo Achilles (TA) insertion.

Laterally, the calcaneum is subcutaneous and the sural nerve runs obliquely within the subcutaneous fat passing posterosuperior to anteroinferior with a variable course. It supplies the lateral border of the foot and is easily damaged in direct incisions over this area which may cause neuromas.

Laterally above the calcaneum the soft tissues consist of superficial and deep triangles. The superficial triangle lies in the sagittal plane. Its boundaries are the superior border of the calcaneum inferiorly, anteriorly the peroneal muscles and tendons and posteriorly the TA. In the anterior wall of the superficial triangle, in the coronal plane is the deep triangle. It is bounded laterally by the peroneal tendons, inferiorly by the superior border of the calcaneum, just behind PFSTJ and medially by the flexor hallucis muscle covered by fascia. The floor from inferior to superior is PFSTJ, STJ capsule, talus, ankle joint capsule, and tibia. Surgical dissection of these triangles by the extended lateral approach gives massive access to the hindfoot.

The posterior peroneal artery is the artery of supply of the skin of the lateral aspect of the heel. It is usually the terminal branch of the peroneal artery and enters the deep triangle at its apex. It transits both triangles, anastomosing with the periarticular vascular ring around the ankle and crosses the superior border of the calcaneum behind PFSTJ in close proximity to the sural nerve, becoming an end artery. There are poor anastomoses between the posterior peroneal artery cutaneous angiosome and the posterior foot or the sole. Therefore a surgical approach to the lateral side of the hindfoot must dissect the angiosome or the wound is at high risk of breakdown.

Medially, the short abductor of the foot and flexor accessorius muscle separate the bone form the posterior tibial neurovascular bundle, which is in danger from medial incisions, lateral drills or instruments placed through the primary fracture line to reduce the body fragment (BF). It may also be damaged by the inferior spike of the sustentacular fragment (SF) which pierces the skin in an open fracture.

Fractures of the calcaneum occur according to a series of readily definable patterns knowledge of which permits a logical approach to treatment.

This constitutes approximately 75% of cases and is usually caused by a fall from 6–12 feet (1.8–3.6m). It involves three fracture lines, the primary fracture line (1#L) and the coronal (C2#L) and longitudinal secondary fracture lines (L2#L) (Figure 12.61.2), modified from the original description of Essex-Lopresti.

1#L is the result of shearing forces between the heelstrike point and the mechanical axis of STJ (Figure 12.61.2). It splits the bone from posteromedial to anterolateral, crossing PFSTJ and usually CCJ creating a two-part fracture. The lateral fragment contains the lateral part of PFSTJ, the tuberosity or body of the calcaneum and the lateral part of CCJ while the medial fragment contains ST and the medial part of the subtalar and CCJ.

The two-part fracture is usually undisplaced, however the posterolateral fragment may dislocate lateral to the talus, either in a high-energy injury, or in middle aged females after a minor trip. As the lateral fragment is forced upwards, it escapes lateral to the talus and continues superiorly until stopped by the lateral malleolus, which sustains a small posterior fracture. The lateral fragment rebounds and pulls the lateral edge of the talus inferiorly, subluxing the ankle joint. This rare fracture is often missed and non-operative treatment leads to painful ankle and midfoot dysfunction which is difficult to salvage. Primary operative treatment through an extended lateral approach is straightforward.

Usually secondary fracture lines occur. C2#L runs along the sinus tarsi splitting the anterolateral fragment (ALF) from the posterolateral. Crossing 1#L in the majority of cases, it exits at the middle facet, splitting the medial fragment into an anteromedial fragment (AMF) and a posterior SF. L2#L arises on the lateral wall of the calcaneum and passes posteriorly splitting the residual posterolateral fragment into a lateral joint fragment (LJF) and a body fragment (BF). Usually it skirts PFSTJ creating a small semilunar, central joint depression LJF. Less frequently it passes directly posteriorly to the posterior aspect of the bone, creating a large, tongue type LJF.

Thus a four- or five-part fracture is created, depending on whether the coronal secondary line stops medially at 1#L.

In a four-part fracture, where C2#L does not cross 1#L (approximately 30%), AMF remains part of SF. Open reduction and internal fixation (ORIF) is simple since the combined SF and AMF provides a large area for screw insertion. Occasionally, a four-part fracture is created by 1#L failing to pass anterior to C2#L. This leads to a combined ALF and AMF.

The interaction of 1#L and C2#L usually produces a BF which has a sharp, wedge-shaped superior edge (Figure12.61.3). The injury forces BF superiorly and anteriorly, in a variable direction, sliding laterally on the oblique lateral surface of SF and tips into varus and internal rotation (Figure 12.61.3). The triangular upper surface of BF splits apart LJF and SF, tipping LJF into valgus and SF into varus. With increasing fragment displacement, the sharp inferior spike of SF becomes more medial, until it penetrates the skin causing an open fracture.

Occasionally, in high energy or osteoporotic fractures, the usual sharp triangular upper border of BF is absent. LJF is crushed into BF and may be captured within it causing true lateral joint fragment depression (Atkins type 3 fracture).

Displacements of AMF and ALF are less marked. AMF is undisplaced or shifted upwards. ALF rotates outward and upward filling in the crucial angle of Gissane. These displacements must be addressed in ORIF to prevent painful STJ impingement.

A number of complementary fracture classifications are useful:

The classical tuberosity fracture is a TA avulsion in an osteoporotic bone.

The medial process fracture of the body of the calcaneum was originally described by Watson-Jones, as due to a fall with the foot in severe valgus and by Bohler, who considered it to be an avulsion of the plantar fascia.

We have identified a fracture of the calcaneal tuberosity that occurs in young adults (Figure 12.61.4). 1#L is replaced by a semi-coronal fracture line, which separates the posterosuperior part of the calcaneum. This fracture line may cross PFSTJ or pass posteriorly. The fracture line exits on the posterior wall of the calcaneum. The displaced fragment includes TA insertion and rotates upwards causing a heel boss.

There are two different types, avulsion and compression.

The more common bony avulsion of the calcaneal origin either of the bifurcate ligament or of the extensor digitorum brevis is caused by forced inversion. There is tenderness on the lateral side of the hindfoot and the injury is usually obvious on the lateral x-ray. Non-operative treatment which may require cast immobilization gives good results although recovery may be slow.

The rare high violence compression fracture is caused by forced abduction of the foot with compression of the anterior part of the calcaneum, classically either in motorcycle racing or waterskiing. The displaced fragment is larger than in the compression fracture and involves a significant portion of CCJ. Swelling is often considerable and CT scanning may demonstrate associated fractures of the calcaneum. Non-operative treatment gives poor results. Surgery is difficult and requires often involves stabilization of PFSTJ.

ST is small and fractures may be missed radiographically. ST is firmly attached to talus and medial malleolus, so fractures are rarely isolated and are associated with severe ligamentous and bony damage elsewhere and treatment is a part of treatment of the overall hindfoot injury. ST fractures are often associated with gross instability of PFSTJ.

These are rare but easily missed. The usual mechanism is a jump or fall; however lawnmower accidents may directly involve the calcaneum. In younger children undisplaced extra-articular fractures predominate, with a high incidence of anterior process fractures. The prognosis is good with non-operative treatment. Adolescent fractures are rare, similar to adult fractures but simpler although occurring following greater falls (Figure 12.61.5).

Two types are seen. Type 1 is a standard highly displaced intra-articular fracture where the inferior border of SF penetrates the skin on the medial side of the foot beneath the medial malleolus.

A type 2 injury occurs in a high violence atypical fracture where random fracture fragments penetrate the skin. The open injury varies but is typically on the sole of the foot.

The majority of fractures occur in a fall from a height, usually more than 6 feet (1.8m). A two part fracture dislocation in a middle aged women or the avulsion fracture of the tuberosity in the elderly occur after a simple trip. Both open and bilateral fractures are associated with greater violence injuries and give poorer results. The other common cause for calcaneal fractures is a road traffic accident and in these cases atypical fractures, sometimes with dislocations are seen.

The patient experiences immediate hindfoot pain and cannot walk. Swelling soon follows. Initial clinical examination usually demonstrates swelling and tenderness of the heel. Very rarely, a calcaneal fracture with a dislocation will cause vascular compromise in the foot. Swelling increases over several days and bruising of the lateral side of the heel becomes obvious (the Battle sign). As the swelling subsides, the characteristic short, wide heel and poorly defined lateral malleolus become obvious.

The two part fracture dislocation of the body of the calcaneum presents a clinical trap. The x-ray may look deceptively normal and, because the calcaneum is impacted against the lateral malleolus, the patient may be able to walk with ease.

Lateral and axial views of the heel will show most clinically significant fractures. Ankle and foot radiographs may also be performed. On the lateral radiograph assessment of Bohler’s angle will give some indication of fracture displacement (Figure 12.61.6). The fracture may also be classified according to Essex-Lopresti into a tongue or central joint depression fracture. The axial view will demonstrate 1#L separating BF from SF and may give some indication of heel widening (Figure 12.61.7). Ankle radiographs will demonstrate subluxation with a dislocated calcaneal tuberosity in the case of a two-part fracture dislocation. Oblique radiographs of the foot demonstrate fractures of the anterior part of the calcaneum.

Fractures may easily be missed on plain radiographs and in case of doubt a computed tomography (CT) scan should be performed. CT scanning is essential to demonstrate fracture anatomy and displacement and for surgical planning. Using a spiral scanner, axial, sagittal and semi-coronal (normal to PFSTJ) views are obtained.

Semi-coronal scan (see Figure 12.61.3) shows the disposition of the fracture in the posterior part of the bone. PFSTJ is well demonstrated and BF displacement can be assessed. The composition of the fractured lateral wall can be determined. In the context of reconstruction of mal-union, impingement between displaced fracture fragments and the fibula can be assessed.

Axial scan (Figure 12.61.8) shows the fracture as it effects the anterior part of the bone well. Involvement of CCJ is clearly seen and fracture lines passing just anterior to ST can be visualized. In the posterior part of the bone, rotation of BF in the axial plane can be estimated. The scan will also show whether the fracture is an Essex-Lopresti tongue or central joint depression fracture, although this is normally readily seen on the lateral radiograph.

Treatment remains controversial; however, with improved surgical understanding, anatomical approaches and implant technology, operative treatment is becoming the norm.

This should be reserved for undisplaced fractures or for cases unfit for operative treatment. After elevation to resolve swelling, the patient is mobilized non-weight bearing with physiotherapy. If this is too uncomfortable, a short period of initial immobilization is used. An elastic stocking aids resolution of swelling. The patient should be fully weight bearing by 12 weeks in a solid shoe with a permanent insole.

There are four goals to calcaneal fracture fixation

The surgical approach is crucial and develops a fasciocutaneous flap based on the terminal branch of the peroneal artery. The incision heals well and allows early mobilization. The medial wall fracture line can be addressed through this lateral incision obviating the need for a medial approach.

Surgery is performed after the swelling has begun to subside and under general anaesthetic and antibiotic cover. The patient is placed in the lateral position and the foot prepared and draped free from the mid-calf.

The incision is in two parts joined at the posterior corner of the heel. The superior limb begins in the midline approximately 15cm above the sole and passes inferiorly and anteriorly ending approximately 2cm anterior to the lateral corner of the heel. The inferior limb begins distally at the level of the base of the fifth metatarsal bone at the junction of the lateral side of the foot and the sole. It is below the bruised skin and separated from it by approximately 1cm. The two limbs meet at an angle of greater than 100 degrees in a gentle curve. The skin incision allows development of the cutaneous angiosome of the posterior peroneal artery. Flap elevation begins at the apex with dissection directly onto the calcaneum. Anteriorly, abductor digiti minimi is split and the entire lateral wall of the calcaneum is exposed subperiosteally as far as PFSTJ. The inferior peroneal retinaculum is dissected intact to expose of the crucial angle of Gissane and ALF. The lateral wall fragment is now removed and preserved for later reposition. This may require formal osteotomy.

LJF is rotated out of STJ. In a tongue type fracture the posterior soft tissues should be retained. In a central joint depression type fracture, the fragment will usually have been denuded of soft tissues and is removed. Exposure of the posterior aspect of STJ is improved by cutting directly through the superficial and deep triangles, avoiding damage to the peroneal tendons and flexor hallucis muscle.

This exposes the medial wall fracture line, between the apex of BF inferiorly and the lateral surface of SF medially and superiorly. A Steinman pin may be used for manipulative reduction of BF. I have not found this to be necessary.

A periosteal elevator is inserted gently between the visible apex of BF and the lateral edge of SF. Care is taken to avoid damage to the posterior tibial neurovascular bundle. The periosteal elevator is now rotated, levering BF downwards and medially, reducing the medial wall. The reduction may be held temporally with a K-wire.

The PFSTJ is now reconstructed anatomically and LJF is replaced. Fixation of intermediate fragments may require K-wires or Herbert screws. Temporary K-wire fixation is checked visually and radiographically. Definitive fixation is with a small fragment cortical lag screw into ST with a washer.

Subperiosteal dissection within the sinus tarsi allows reduction of ALF and AMF, which are stabilized with temporary K-wires. The lateral wall fragment is now replaced. If a good reduction has been obtained it fits well into the remaining lateral bone defect.

The majority of standard calcaneal fractures do not require a locking plate. Once BF has been reduced beneath SF and PFSTJ stabilized by repositioning of LJF, the fracture is longitudinally stable and the plate serves to buttress BF against SF and to hold the anterior part of the bone in place. Union occurs rapidly possibly with a minor, irrelevant loss of height. Where significant bone crushing, comminution or osteoporosis renders the fracture longitudinally unstable, a locking plate is required. In these cases bone grafting may be advisable in order to enhance bone healing and prevent collapse.

Postoperatively ankle and subtalar joint exercises are begun immediately and the patient remains non-weight bearing until union is well advanced, usually at 6–8 weeks. Weight bearing is then gradually introduced.

Isolated medial process fractures are invariably managed conservatively.

Tuberosity fractures involving the upper part of the calcaneum fare poorly non-operatively. Healing is slow with a heel bump and weakened plantarflexion. An extended lateral approach is used to compress the fracture line using a posterolateral tension band. A short period of cast immobilization may be necessary; however, the patient can usually mobilize weight bearing and union is rapid.

Comminuted fractures of the calcaneum fare poorly non-operatively but they are a daunting surgical prospect and will not be suitable for standard fixation. There is invariably at least one large fragment of bone, which usually contains the majority of PFSTJ and BF. ORIF using an extended lateral approach reduces the large fragment into its anatomic position beneath the talus and fixes it with K-wires into the talus. The remainder of the calcaneum is then fixed to this fragment. Non-weight-bearing cast immobilization is maintained until fracture healing is established, usually 6–8 weeks. The K-wires are removed and the patient mobilizes freely in a new cast until union is complete, after approximately a further 6–8 weeks. Treated thus, patients complain of few symptoms and revision to subtalar fusion is rare.

We do not advocate a subtalar fusion at the time of primary reduction. Subtalar fusion without prior reduction gives poor results.

Sometimes, a comminuted fracture combines features of a standard intra-articular fracture with those of a tuberosity fracture. In these cases, reduction is maintained by a combination of plates and screws and a tension band wire.

Type 1: the fracture is more displaced than the average and therefore untreated the outcome is poor. The open wound is debrided primarily and the foot elevated. By the time that the soft tissues have settled sufficiently to allow internal fixation, the open wound is usually healed and reduction and internal fixation are performed as outlined previously. Alternatively, ORIF may be performed at the time of initial wound debridement.

Type 2: these are among the most challenging hindfoot injuries to manage. Treated conservatively, the severe displacement leads to major disability and the combination of open wounds and unstable fracture fragments predisposes to chronic infection so that there is a high chance of late amputation. Operative treatment is very difficult and plastic surgical cover may be necessary. Surgical treatment may precipitate amputation but on balance it is the better option.

In all open cases and particularly where the open wound is more serious, the risks of ORIF must be carefully weighed against the likely outcome of non-operative management in order to determine whether operative management is indicated.

Treatment is determined by the associated injuries. ORIF may be with a lateral to medial lag screw through an extended lateral approach or from medial to lateral using a direct medial incision. However, the importance of the ST fracture is the instability which it confers on PFSTJ. It is often better to reduce PFSJT under direct vision and stabilize it with a 2mm K-wire. The patient is then mobilized non-weight bearing for 6 weeks in a cast and the wire is then removed.

Calcaneal fractures in very young children heal uneventfully and treatment consists of immobilization until healing in a few weeks. In older children (see Figure 12.61.5), there is significant scope for remodelling of the hindfoot even after a displaced fracture. The aim of treatment is to provide a fully functional hindfoot with the minimum intervention possible. Minor joint and hindfoot malalignments even out with time but large displacements should be treated by operative reduction. Owing to the simple fracture pattern in adolescents, ORIF is straightforward and gives excellent results without damage to the calcaneal apophysis (Figure 12.61.5).

Toe clawing is common after calcaneal fracture and while this may be due to a missed compartment syndrome, it is more likely to be the result of damage to the intrinsic muscles of the foot at the time of fracture. Foot compartment syndrome does occur and may be common after calcaneal fracture. This suggests that if the patient has clinical features of a compartment syndrome with excessive pain, sensory abnormalities, and raised compartment pressures, decompression should be performed if the patient has been evaluated within 24h. However, the open wounds of compartmental decompression may preclude subsequent ORIF because of the risk of infection. Therefore, either ORIF should be undertaken at the time of decompression or the morbidity of an unreduced calcaneal fracture will need to be traded against the disability of untreated compartment syndrome.

In an attempt to avoid the massive exposure and consequent morbidity of the extended lateral approach, a number of different percutaneous methods of reduction and fixation have been devised. In some techniques an external fixator is used. They are applicable to a limited range of fractures and must be undertaken at an early stage. Perfect reduction is not obtained but the avoidance of the morbidity of open surgery may compensate for this. Early reports of these techniques are encouraging. It is important to note that the techniques all require a thorough knowledge of fracture anatomy and are generally undertaken by surgeons skilled in calcaneal fracture surgery.

The results in some individual groups are outlined earlier. Despite a bewildering array of papers, the evidence base for calcaneal fracture treatment is unsatisfactory in that ‘level 1 evidence’ is not available as with much of orthopaedic surgery. The historic literature is difficult to interpret because it is impossible to know the exact nature of the fracture described and more modern studies are small or scientifically flawed or employ outmoded fixation techniques.

In general terms the evidence base for calcaneal fracture outcomes may be summarized as follows.

In deciding whether to treat a calcaneal fracture by ORIF, knowledge of the expected disability and management of a conservatively treated fracture is essential. The problem is that there are multiple causes of symptoms and overlapping disability syndromes. The patient will complain of a combination of pain, limitation of walking ability and derangement of their lifestyle and a superficial history and examination may give little indication of the true cause of the problem. In the past, excessive concentration on PFSTJ as the major cause of symptoms has clouded the issue. In a calcaneal malunion, careful assessment will usually reveal one or more of the following:

Angular PFSTJ malalignment is invariable in a standard intra-articular calcaneal fracture. It may cause minimal early symptoms. The more severe the malalignment and the greater STJ comminution, the more likely is the development of painful arthritis later. This causes pain on walking particularly on uneven ground. Rest pain is a late feature.

In the presence of normal hindfoot biomechanics, subtalar joint symptoms are not usually a significant problem unless the patient in a heavy manual worker or regular rough ground walker. Therefore, isolated angular PFSTJ malalignment is not a strong indication for ORIF and symptoms may be treated with fusion. However, angular PFSTJ malalignment is usually associated with abnormalities of hindfoot biomechanics.

True lateral joint fragment depression invariably causes serious disability. There is a sense of insecurity and giving way within the foot with lateral pain on taking a step. With time rest pain occurs. Examination reveals tenderness laterally and a valgus hindfoot. This severe disability is an inevitable consequence of subtalar depression and this feature is a strong indication for ORIF.

This is due principally to BF displacement; this is a common cause of severe disability. Three syndromes occur: heelstrike medial, heelstrike lateral, and short heel.

BF displacement has carried the heelstrike point medial to the axis of the hindfoot, the unloaded hindfoot lies in varus, accentuated on weight bearing. These patients complain of severe difficulty in walking or standing. There is a cavus midfoot and the medial ray is unloaded. At toe-off, the varus is accentuated because of TA medialization. Supination instability is common and the patient may walk on the outer border of the foot. FHL is often trapped in the fracture. Degenerative changes of the ankle and midfoot occur rapidly with increasing pain.

Conservative treatment of these feet is of little use. The only satisfactory solution is surgical reconstruction of the heel and this is made particularly difficult by the varus position of the hindfoot. Therefore, BF varus and internal rotation position, which will produce a heelstrike medial syndrome is a strong indication for ORIF.

This is more benign than heelstrike medial but less common. There is a valgus heel with fibular impingement and a planus midfoot, accentuated and painful on load bearing. Compensatory overactivity of tibialis posterior causes calf pain. However, resection of the lateral bony boss will make matters worse by allowing the heel to collapse further into valgus. Likewise, in situ fusion of STJ will destroy the compensatory effect of subtalar inversion and may make matters worse.

Treatment by a medial shoe-raise and supporting insole is often extremely effective in these cases. Operative treatment to reconstruct the hindfoot biomechanics and fuse STJ is easier than in the case of heelstrike medial.

Following a calcaneal fracture, the heel is always shortened and broadened in relation to the extent of the displacement. However, when the heelstrike is displaced medially or laterally, the symptoms from this shortening are usually masked by those more intrusive problems.

The short broad heel causes problems with shoeware and sometimes the broadening is sufficient to cause lateral pain beneath the fibula. The major problem is, however, weakness of plantarflexion due to reduction of the moment arm of the gastrocnemius-soleus complex. In order to compensate for the short heel, the ankle is held in dorsiflexion and if the problem is severe, there may be an overall apparent equinus deformity of the foot. The abnormal posture of the ankle may lead to secondary arthritis. The patients characteristically complain of weakness of the foot and limping, while in a severe case, the equinus may lead to catching the foot. Later ankle arthritic pain becomes a feature.

Treatment is by a heel raise to restore the ankle to neutral and protect it; however, the patient often finds that this makes them symptomatically worse by exaggerating the weakness of the plantarflexors. Operative treatment is by hindfoot reconstruction. If treatment is delayed until ankle arthritis supervenes, the situation is difficult to recover.

Owing to its attachment to the bifurcate ligament, the anterior part of AMF is rarely displaced following a fracture. The posterior part is attached to the talus and may ride upwards compared to PFSTJ. The displacement is seldom great, however even this small malalignment may contribute to blocking subtalar joint movement. In contrast, ALF will often tip upwards because of its attachment to the inferior peroneal retinaculum. As it does so its posterosuperior border fills in the crucial angel of Gissane preventing eversion of heel and in severe cases causing a fixed inversion deformity. When this is combined with a medial translation of the heel due to BF movement, the resulting disability is severe.

ALF syndrome is seen in untreated isolated compression fractures or in inadequately treated fractures where the crucial angle of Gissane has not been correctly addressed. The patient complains of pain, initially only on attempted eversion. Gradually the pain becomes more intrusive, occurring first on walking on rough ground, then on any walking, on standing and finally as arthritic changes occur at rest. Rarely a late spontaneous fusion will occur. In my experience excision of the displaced fragment at a late stage does not relieve symptoms and fusion combined with reconstruction of the hindfoot is necessary.

These symptoms are an inevitable result of the displacement of LJF and I regard displacement of this fragment as a strong indication for ORIF of the fracture.

The specialized weight-bearing tissues of the heelpad are not permanently damaged in a calcaneal fracture and heelpad pain is rare after ORIF. However, in a displaced calcaneal fracture, shards of bone may penetrate the deep structures of the sole of the foot. If the fracture is treated conservatively, these pieces unite in their displaced position. These patients are always severely disabled clinically. They walk with a severe limp and great pain, although rest pain is rare. Treatment is very difficult. Thick insoles are of some help but reconstructive surgery is usually required and it is difficult to remove all the bone at this stage. Even a radical removal of the protruding bone combined with reconstruction does not relieve the heelpad pain. In contrast, acute fracture reduction removes the shards from the sole and heelpad pain does not occur. Therefore I regard bony protrusion in the heelpad as a strong indication for operative treatment of a fracture in the acute stage.

During a calcaneal fracture, lateral wall expansion closes the space between it and the fibula and compresses or even dislocates the peroneal tendons. In a severe case, the laterally displaced calcaneum will articulate with the lateral malleolus, defunctioning the ankle joint. Isolated lateral wall protrusion is effectively treated by simple resection. However, fibular impingement is usually associated with abnormal hindfoot biomechanics due to BF displacement. Simple lateral wall resection in these cases may cause further valgus collapse of the heel, worsening symptoms.

After ORIF, metalwork removal is frequently necessary, which may be combined with arthrolysis of PFSTJ. This will often improve symptoms of apparent subtalar arthritis. It is therefore reasonable to do this surgery and defer fusion in a marginal case. In situ subtalar arthrodesis may be required for degenerative change but usually this is deferred to 2 years, since symptoms may settle for this period. It is performed either through the extended lateral incision or a sinus tarsi approach.

Calcaneal malunion surgery is technically highly demanding surgery. The case is analysed by careful clinical examination, plain radiology, and CT scanning. I do not find gait analysis or pedobarography of use. Non-operative treatment consists of modification of shoeware, the use of supportive and cushioning insoles and even a caliper, and change of lifestyle to cope with the disability. Some care must be exercised in pursuing a conservative course. Calcaneal malunion surgery is a major undertaking. There may well be morbidity from the bone graft donor site and if deep infection occurs, amputation is likely. However, a significantly misaligned calcaneum will cause a dorsiflexed talus leading in time to ankle arthritis, while bone beneath the lateral malleolus will eventually cause peroneal tendon dislocation or rupture. In addition, the hindfoot malalignment strains Chopart’s joint causing arthritis. In these circumstances reconstruction needs to be performed early for optimal results. The problems that will be encountered include lateral impingement, peroneal tendon dislocation, PFSTJ arthritis, hindfoot malalignment, and bone in the sole of the foot.

The aim of surgical reconstruction is to restore the biomechanics and fuse degenerate joints. In situ subtalar fusion is ineffectual except rarely where there is symptomatic PFSTJ degeneration with normal hindfoot biomechanics.

Surgery is invariably performed through an extended lateral approach and proceeds stepwise, correcting only the necessary problems. The protruding lateral wall is resected. Dislocated peroneal tendons are located. PFSTJ is entered and laminar spreaders used to derotate the talus into correct orientation. PFSTJ is prepared and the talus held in its corrected position with a bone block from the ileac crest. An extra-articular calcaneal osteotomy is undertaken and used to place the heelstrike point in the correct place. If necessary, a bone block is used to hold the correction. The peroneal tendons are relocated in a new groove behind the lateral malleolus. The wound is sutured in three layers beginning with the periosteum.

In a two-part fracture dislocation, the reconstructive surgery is different. Through the extended lateral approach, the primary fracture line is found inferomedial to the talus. It is re-opened and the dislocated calcaneal body relocated. A PFSTJ fusion is undertaken if necessary.