21 Fractures of the Distal Tibial Metaphysis Involving the Ankle Joint: The Pilon Fracture

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21.2 Overview

21 Fractures of the Distal Tibial Metaphysis Involving the Ankle Joint: The Pilon Fracture

D. Stephen

21.1 Introduction

The pilon fracture is a metaphyseal injury extending into the ankle joint. The complexity of this injury continues to challenge most, if not all orthopedic surgeons.

Over the past decade, there has been a shift in emphasis from the fracture as an isolated entity to an understanding that the soft tissue injury plays a large role in the outcome of treatment, This has resulted in a considerable change in the treatment, both from a perspective of timing as well as technique of frac- ture fixation. Coupled with this increased awareness regarding the importance of the soft tissues, there have been changes in the implants used for fracture fixation. This chapter will review these issues, as well as the results and complications of this complex injury.

The major problems affecting the natural history of the high-energy distal tibia fracture may be sum- marized as follows:

1. The nature of the injury 2. The state of the bone 3. The state of the soft tissues 4. Technical difficulties

21.2 Overview

21.2.1 Nature of the Injury

Fractures in cancellous bone are subject to either compressive or shearing forces, each imparting its own particular type of injury on the bone (Figs. 21.1, 21.2). Compressive forces cause severe impaction, whereas shearing or tensile forces cause marked dis- ruption of the bone and soft tissues without impac- tion, resulting in gross instability. A fracture caused

by a combined shear and compressive load may pres- ent with both impaction of the articular surface and instability of the metaphysis as well as damage to the soft tissues due to the lack of muscle cover to the medial border of the tibia.

Severe compression injuries are often seen in patients falling from a height, whereas shearing inju- ries are often seen in skiing injuries, the so-called boot-top fracture, or major motor vehicle trauma.

It is with the complex force patterns of high-energy motor vehicle trauma that a combination of these types of injuries may be seen.

The prognosis of the injury depends on the amount of articular damage compared to the metaphyseal damage (as is clearly evident in Fig. 21.1), and is reflected in the revised classification. The prognosis will also depend on the handling of the soft tissues during internal fixation.

21.2.1.1

Axial Compression Tibia

Articular Cartilage. Severe compression (Fig. 21.1a) usually causes impaction of the articular surface, often with marked comminution (Fig. 21.1b,c). On some occasions, the comminution is so great that anatomical repair of the articular surface is virtually impossible. If surgical repair is attempted, small avas- cular pieces of articular cartilage and subchondral bone may have to be discarded, leaving gaps on the joint surface. Osteoarthritis will inevitably follow no matter what form of treatment is used.

Metaphysis. Fractures of the distal metaphysis caused by compression associated with a rota- tion force often severely impact the metaphy- seal bone, causing unacceptable axial malalign- ment (Fig. 21.1d). The result of uncorrected axial malalignment in the lower extremity is abnormal stress on the distal joint, which in time will destroy it. In the lower extremity, anatomical alignment is

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21.2 Overview

necessary to prevent these major forces of weight bearing from destroying the joint.

Therefore, when these impacted fractures are reduced by closed manipulation, an extremely large periarticular gap is formed (Fig. 21.1d–h). Nature abhors a vacuum – if treated nonoperatively, the distal fragment may tend to displace into that gap in the postreduction period, necessitating multiple reductions. Also, since the compression fracture has been disimpacted, and since cancellous bone heals poorly under such conditions, union may be delayed. This, in turn, will require prolonged immobilization of the limb, with resultant poor ankle function.

Fibula

In many compression injuries the fibula may remain intact, which it never does in the shearing-type injury.

With an intact fibula, the ankle is often driven into varus with severe impaction of the medial part of the tibial plafond (Fig. 21.1b,c).

21.2.1.2 Shear (Tension)

Tibia

Articular Cartilage. Pure shearing or tensile forces, free of axial loading and usually rotatory in nature, may spare the articular surface (Fig. 21.2a,b). Minor

Fig. 21.1a–h. Compression injury to the distal tibia. a Direction of the compressive force. b,c A slight varus addition to a com- pressive force often causes impaction of the distal tibial articular surface, leaving the ﬁ bula intact, as shown on the radiograph.

d A valgus addition to the compressive force may cause impaction of the distal tibial metaphysis with a fracture of the ﬁ bula.

e,f Radiographs of a 43-year-old woman who sustained the latter type of injury while skiing. Note the extreme valgus position of the distal tibia. g,h A closed reduction under general anesthesia restored axial alignment, but resulted in an extremely large gap on the anterior and lateral surface of the distal tibia, as shown by the arrows.

a b c

d

e f g h

Compression

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21.2 Overview Fig. 21.2a–d. Shearing injury to the distal tibia. a The shearing force in valgus which

fractures the ﬁ bula as well as the distal tibial metaphysis. b Anteroposterior radiograph showing a fracture of this type with comminution of the ﬁ bula. c Shearing injury of the distal tibial metaphysis combined with a compression force, resulting in severe comminu- tion of the articular cartilage. d Radiographic appearance of such a case

Shear

a

b

d c

Compression Resultant vector

Shear

cracks may appear at the joint surface, but severe impaction is rare. The long-term prognosis, there- fore, is more favorable than for injuries with major articular compression.

Metaphysis. The shear injury to the distal tibia pro- duces an unstable injury with a disrupted soft tissue envelope. Although the articular surface may be rela- tively intact, the unstable nature of the bony injury, if treated nonoperatively, often requires immobiliza- tion, with resultant stiffness of the ankle.

Fibula

The fibula is always fractured, usually as a result of a valgus external rotation force (Fig. 21.2b). The fibula

fracture is usually transverse or short and oblique in nature, with a butterfly fragment. However, on occa- sion, the fibula is markedly comminuted, making any reconstruction difficult.

21.2.1.3 Combined

Severe high-energy trauma may produce a com- bined injury, with both shearing and axial compres- sive forces (Fig. 21.2c,d). It is obvious that the lesion found in a particular patient, i.e., the personality of the individual fracture, is the result of a resolution of these forces. Therefore, a spectrum of possible injury exists, depending on the involvement of the articu- lar surface, the metaphysis, and the fibula (Fig. 21.3).

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21.2 Overview

The natural history will in a large measure depend on these factors and will significantly affect one’s management decisions.

21.2.2 State of the Bone

In younger patients with good-quality bone, the surgeon may expect that the holding power of the screws will be satisfactory. However, like fractures in many other areas of the body, metaphyseal fractures of the distal tibia often occur in elderly patients with osteoporotic bone, which makes stable internal fixa- tion difficult to obtain. The development of locking screws and plates will hopefully reduce the incidence of hardware failures in this area.

21.2.3 State of the Soft Tissues

The importance of the soft tissues in open fractures has been stressed in the medical literature for decades.

Tscherne and Gotzen (1984) stressed the equal impor- tance of the state of the soft tissues in closed fractures.

Their grading system is particularly appropriate to the distal tibial fracture, where major soft tissue damage is so common and the consequences of soft tissue loss so disastrous. Tscherne and Gotzen’s grading of soft tissue injuries for closed fractures is as follows:

– Grade 0: little or no soft tissue injury (Fig. 21.4a) – Grade I: significant abrasion or contusion

(Fig. 21.4b)

– Grade II: deep contaminated abrasion with local contusional damage to skin or muscle (Fig. 21.4c)

– Grade III: extensive contusion or crushing of skin or destruction of muscle; also subcutaneous avul- sions, decompensated compartment syndrome, or rupture of a major blood vessel (Fig. 21.4d) In this particular injury, the state of the skin and subcutaneous tissue is of overriding importance.

Notoriously poor soft tissue healing, often measured in months, is common about the distal tibia. Venous drainage is often inadequate, leading to chronic edema and stasis ulceration. A high-energy injury may severely traumatize this poorly vascularized tissue, either by direct or indirect forces. Since much of the tibia at the ankle is subcutaneous, the skin and subcutaneous tissues, lacking the protection of muscle, may be traumatized by the fracture fragments from within, without an open wound being present.

The resultant massive swelling may lead to the early formation of posttraumatic bullae. Skin necrosis may ensue, especially if the surgeon has chosen to fur- ther traumatize the skin with an ill-advised surgical procedure. Therefore, the timing of the surgery and delicate, atraumatic handling of the soft tissues are of vital importance in the management of this fracture.

21.2.4 Technical Difficulties

We have already discussed some of the important technical difficulties, such as severe comminution of

Fig. 21.3. a The three important anatomical zones to be considered in the decision-making and prognosis of the pilon fracture. 1, articular surface; 2, metaphysis; 3, ﬁ bula.

b Axial CT showing the three classic articular components of the pilon fracture: 1) anterolateral; 2) medial;

3) posterior. These fragments vary in their size and amount of comminution.

a b

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21.2 Overview

the articular surface, impaction of cancellous bone, weak osteoporotic bone, and the precarious state of the soft tissues. In addition to these factors, expo- sure of the distal tibia to fully visualize the articular surface of the ankle is difficult, which further com- pounds the problem.

21.2.5 The Dilemma

A classic «catch 22» situation is obvious: i.e., nonop- erative care may result in persistent joint displace- ment and a poor outcome, but surgical treatment, in turn, is fraught with many difficulties, most sig- nificant of which is soft tissue complications. The concern regarding soft tissues has led to less inva- sive methods of fracture stabilization. These have included percutaneous screw insertion, ring fixa- tion, and most recently percutaneous plate insertion techniques.

The literature on this subject, sparse as it is, reflects this dilemma. Most reports indicate the need for ana- tomical restoration of the distal tibia but suggest that the difficulties and the risks involved are too great.

Williams et al. (1967) and Ruoff and Snider (1971) therefore recommend traction methods as an alter- native to open reduction, with the occasional use of percutaneous pinning in internal fixation of the fibula. However, their number of cases was too small to be significant.

Conrad (1970) described the lateral tibial plafond fracture associated with trimalleolar ankle fractures and made a plea for their anatomical open reduction.

However, that injury is different from the so-called explosion or pilon fracture of the distal tibia, and the conclusions are therefore inapplicable.

The European literature is more extensive, but reaches similar conclusions. Bonnier (1961), DeCoulx et al. (1961), and Fourquet (1959) all reported large series treated by both open and closed methods, with 43%, 45%, and 50% functional results, respectively.

No definite trends were noted.

The reports of Rüedi and Allgöwer (1969) began to shed light on this dilemma. They adhered to the principles of the AO/ASIF group, i.e.:

1. Reconstruction of the fibula (if fractured)

2. Reconstruction of the articular surface of the tibia

3. Cancellous bone grafting of the gap in the distal tibial metaphysis

4. A medial or anterior tibial buttress plate to restore stability

At a 4-year review, they were able to show good functional results in 74% of their 84 patients with pilon fractures.

The same group of patients were reviewed again 9 years after surgery: few had regressed and many had improved their previous rating (Rüedi 1973). For the first time in the literature, these reports indicated that this fracture was amenable to meticulous anatomical open reduction, stable internal fixation, and early motion.

Fig. 21.4. a–d Grading system of soft tissue injury in closed fractures. a Grade 0: little or no soft tissue injury. b Grade 1: superﬁ cial abrasion (shaded area) with local contusional damage to skin or muscle. c Grade 2: deep contaminated abra- sion with local contusional damage (shaded area) to skin and muscle. d Grade 3: extensive contusion or crushing of skin or destruction of muscle (shaded area). (From Tscherne and Gotzen 1984). e Clinical photo of patient with a pilon fracture.

Although the fracture is closed, there are numerous blood- ﬁ lled blisters with swelling, making this patient a “high risk”

for immediate open reduction and internal ﬁ xation.

a b c

e

d

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21.2 Overview

Further reports by Heim and Naser (1977), Rüedi and Allgöwer (1979), and Szyszkowitz et al. (1979) confirmed these findings. The further publications by Rüedi and Allgöwer came from Basel, where 50%

of the injuries were caused by high-energy motor vehicle trauma, unlike their original report, in which most were caused by skiing injuries. They were able to achieve excellent results in 69.4% of their cases, despite the shift of the injuries to a higher-energy type.

However, Kellam and Waddell (1979) indicated in a study of 26 distal tibial pilon fractures that results were more often linked to the type of fracture than to their management. With open reduction of the shear- ing-type injury without major joint impaction, they achieved good results in 84% of the patients, a figure comparable to that of the Swiss group. However, in the severely impacted, comminuted compression type, they achieved only 53% good results. Neverthe- less, the results obtained by operative treatment were superior to those obtained by nonoperative treat- ment.

Teeny and Wiss (1993) examined variables contrib- uting to a poor result in a retrospective study of 58 patients with 60 pilong fractures. The overall clinical rating correlated with the Reudi classification, qual- ity of reduction, and the presence of a postoperative wound infection. The fusion rate for Reudi types I and II fractures was 10%, but for type III it was 26%.

The perils of early open reduction and internal fixation (ORIF) were illustrated by the randomized, prospective study performed by Wyrsch et al. (1996).

Patients were surgeon-randomized, with 19 undergo- ing early ORIF (average of 5 days postinjury) and 20 undergoing external fixation with limited internal fixation of the articular surface. The internal fixation group had a complication rate of 75%, with seven patients incurring 15 major complications, with 28 additional operations: six of these seven patients required free flaps, three of the seven required ampu- tations, and three of four remaining patients had ongoing sepsis. Conversely, there was a 20% compli- cation rate in the external fixation group, with four patients incurring four major complications, with only five additional operations. Only one of these four complications required a free flap. One of the inter- esting conclusions was that the radiographic status did not correlate with the clinical result.

Two more recent studies (Patterson et al. 1999;

Sirkin and Sanders 1999) obtained excellent results using a staged protocol. The initial management involved application of a spanning external fixator with or without fixation of the fibula. If there was an open fracture, the wound(s) were treated in a con-

ventional fashion with irrigation and débridement.

The timing of definitive fixation was determined by the soft-tissues. Patterson et al. (1999) reported on the treatment of 22 C3 fractures. with 77% obtaining good results at an average of 21 days before definitive fixation. Sirkin and Sanders (1999) reported on 56 C3 fractures (22 open). In the closed group, there was a 17% incidence of minor wound problems and 3%

(1/34) incidence of major osteomyelitis. In the open group there was a 10% major complication rate (2/22 osteomyelitis – one requiring a below-knee amputa- tion).

Pugh et al. (1999) reported on 60 patients who were treated with three methods: 21 with an ankle-span- ning half-pin external fixator, 15 with a single-ring hybred external fixator and 24 with open-reduction internal fixation. The authors found external fixation had advantages over open reduction (including two patients with amputation), but there was a signifi- cantly increased incidence of malunion.

21.2.6 Summary

Pollack (2003) and Marsh (2003) reported on patient outcomes following pilon fractures using validated outcome measures. Pollack found that a high per- centage of 80 patients more than 3 years after injury had persistent difficulties including: ankle stiffness (35%); persistent swelling (29%); ongoing pain (33%); and 24% could not return to work as a result of the pilon fracture. The authors found that the pres- ence of two or more comorbidities, being married, having an annual income of less than US $25,000, not graduating from high school, and having been treated with external fixation with or without limited internal fixation, were all significantly related to a poor outcome.

Marsh reported on 31 patients (35 ankles) treated with a mono-lateral Wingeel transarticular external fixator and screw fixation of the articular surface followed a minimum of 5 years following surgery.

Although the majority of patients had showed radio- graphic arthritis, few required secondary proce- dures, and the patients perceived their condition as improved for an average of 2.4 years after the injury.

Have we, at this time, solved our dilemma? The answer, to a certain extent, is yes – but only to a certain extent. The final result of any lower-extremity joint injury is dependent upon the ability of the surgeon to achieve an anatomical reduction of the joint surface.

If this cannot be achieved by closed means, then open

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21.3 Classification

reduction is indicated. If we are to embark upon that course for the distal tibial fracture, it behooves us to pay particular attention to the timing of the opera- tion, to the handling of the soft tissues, and to the pre- cise details of the internal fixation. This, in turn, will avoid many of the complications and should improve the functional results.

However, there will be some fractures in this area that by virtue of their articular cartilage destruction will defy even the most expert surgeon. Also, the soft tissue injury in some patients may be so severe that open reduction is hazardous and therefore other techniques must be performed. In those cases, the prognosis resides more in the injury itself than in the treatment, and poor functional results, often ending in ankle arthrodesis, may be expected (see Fig. 21.10).

21.3 Classification

The Rüedi-Allgöwer (1969) classification of distal tibial fractures is based on the degree of displace- ment of the articular fragments. Fractures are graded as follows:

– Grade I: articular fracture without significant dis- placement

– Grade II: articular fracture with significant articu- lar incongruity

– Grade III: severely comminuted and impacted articular fracture

21.3.1 Comprehensive Classification

The AO group proposed the comprehensive classi- fication of all fractures (Müller et al. 1990) using an alphanumeric code: type A, B, and C in order of sever- ity (Fig. 21.5). This classification in the distal tibia is based on the Rüedi-Allgöwer classification and may be very useful in prognosis, since it clearly defines the following:

– Type I: extra-articular fractures (Fig. 21.5A) – Type II: partial articular fractures that involve

only a part of the articular surface, leaving the other part intact and connected to the tibial shaft (Fig. 21.5B)

– Type III: complete articular fractures in which the articular surface is comminuted and separated from the tibial shaft (Fig. 21.5C)

This classification does not include the fibular lesion, but it does have value in predicting the prog- nosis of the injury.

21.3.2 Use of Classification in Decision-Making

This classification is excellent for documentation purposes, and we recommend it. However, to help us with the management of the individual patient the classification must, as with other fractures, be expanded. Each case is different and must be indi- vidually assessed. We have learned that by answer- ing a series of questions rather than by adher- ing to a precise, unbending classification, logical decision-making will follow. The important ques- tions to ask are related to the state of the fibula, the articular surface of the tibia or talus, and the metaphyseal region of the tibia, as given in the following sections.

21.3.2.1 Fibula

Is the fibula fractured? In cases where it is intact, the injury has usually been caused by a severe varus com- pression force, often crushing the medial portion of the tibial articular surface (see Fig. 21.1b,c). Also, the intact fibula acts as a post, stabilizing the important lateral aspect of the joint, the surgical implications of which are obvious. If the fibula is fractured, then the force involved is usually a valgus shear with resultant severe injury to the lateral aspect of the joint (see Fig. 21.1d,e).

21.3.2.2

Articular Surface of the Tibia

Is the articular fracture displaced and, if so, is it a rela- tively uncomminuted fissure (type B1, C1) or a grossly comminuted shattered lower end of the (tibia type B3, C3) (Fig. 21.2)? Severe impaction and comminution of the articular surface may be irreparable; the final out- come of the case will therefore be more dependent on the answers to these questions than to any others.

21.3.2.3

Distal Tibial Metaphysis

Is the bone in the lower tibial metaphysis normal or osteoporotic? Is the fracture severely comminuted? Is there axial malalignment? Is there impaction of the

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21.3 Classification

Fig. 21.5. a Comprehensive classiﬁ cation of distal tibial fractures (AO-OTA). A1 extra-articular fracture, metaphyseal simple; A2 extra-articular fracture, metaphyseal wedge; A3 extra-articular fracture, metaphyseal complex. B1 partial articular fracture, pure split; B2 partial articular fracture, split-depression; B3 partial articular fracture, multifragmentary depression. C1 complete articular simple, metaphyseal simple; C2 complete articular fracture, articular simple, metaphyseal multifragmentary; C3 complete articular fracture, multifragmentary. b Ruede-All- gower classiﬁ cation. (see text)

a

b

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21.3 Classification

cancellous bone that will cause a large gap following reduction?

21.3.3 Personality of the Fracture

The above are the important questions to ask before embarking upon the treatment of a pilon fracture.

The answers to these questions as well as others will precisely define the personality of the fracture.

The personality of the fracture is dependent not only on the fracture factors discussed in the previ- ous section, but also on the degree of the soft tissue injury. In addition, and equally as important, there are patient factors such as the age of the patient, the state of the bone, the associated injuries, and the general medical state. A consideration of all these factors will lead the surgeon to a logical man-

agement decision for each patient. Many permuta- tions and combinations are possible. For example, an undisplaced fracture into the ankle joint with marked comminution and displacement of the metaphysis is suitable for careful reconstruction.

Because the articular surface is not beyond repair, with ideal treatment an excellent result should be expected (Fig. 21.6).

By contrast, in the case of a severely comminuted impacted fracture of the articular surface of the ankle joint, with or without axial malalignment in the metaphysis, even the most careful open reduction may fail to restore joint congruity, which will inevita- bly lead to a poor result (Fig. 21.7). In such a case, so much articular comminution is present that surgery cannot possibly restore it. Open reduction should therefore be avoided, and traction methods such as a spanning external or ring fixator should be employed (Fig. 21.8).

Fig. 21.6a–d. Pilon fracture with good prognosis. a Anteroposterior and lateral radiographs of a 32-year-old man injured while skiing. Note that the fracture involves only the anterior portion of the articular surface. b Postoperative radiographs show anterior plate ﬁ xation for the tibia and lateral plate for the ﬁ bula fracture a

d b

c

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21.3 Classification

Fig. 21.7a–d. Pilon fracture with poor progno- sis. This 31-year-old woman was involved in a motor vehicle accident, sustaining injuries to the left distal metaphysis. a,b The fracture of the right ankle shows severe comminution of the distal tibia, with marked destruction of the articular surface and an intact ﬁ bula. c Postop- erative radiographs with nonanatomic articular reconstruction using two plates and a syndes- mosis screw. d Clinical photos of the latissimus free tissue transfer required for incision break- down and infection

a b c

d

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21.3 Classification Fig. 21.8a–f. A pilon fracture treated with percutaneous minimal internal fi xation of the joint and an external fi xator. a The anteroposterior x-ray reveals a distal tibia fracture into the joint with marked comminution of the metaphysis. A major injury to skin and soft tissues accompanied this fracture. In addition, this patient was a heavy smoker with peripheral vascular dis- ease. b Because of that, initial treatment consisted of fi xation of the fi bula, and a plaster splint. c Tomogram shows impaction, posterior malleolus comminution, and posterior subluxation of ankle joint, with CT showing location of articular impaction.

d Postoperative anteroposterior and lateral radiographs following wound débridement and application of a spanning external ﬁ xator show residual articular impaction (arrow). e Intraoperative lateral radiograph shows curved impactor inserted via a small proximal incision “elevating” impacted fragment. The fragment is then stabilized with a percutaneous anterior-to-posterior cancellous screw. f Approximately 6 weeks later, posterolateral bone grafting was performed for the metaphyseal comminution, and the result at 2 years was excellent

a b

c d

e f

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21.3 Classification

Also important is the soft tissue injury. Using the Tscherne and Gotzen classification, the types 0 and 1 soft tissue injuries may be suitable for standard open reduction and internal fixation techniques, using atraumatic techniques. Types 2 and 3 soft tissue inju- ries, in contrast, will usually require alternative meth- ods, such as the staged protocol outlined above.

21.4 Assessment

Theoretically, the decision-making process should be relatively easy in this major weight-bearing joint fracture. Since we believe that any displaced fracture of a major weight-bearing joint requires anatomi- cal reduction, stable internal fixation, and early joint motion for optimal end results, then any such fracture in the distal tibia should be treated in that manner.

However, because of the problems previously stated of severe bone comminution, osteoporosis, and poor soft tissues, exceptions must be made.

As with all fractures, a careful assessment of the patient, the limb, and the injury, taking into account the expertise and experience of the surgeon, will aid in the decision-making process.

21.4.1 Clinical

General details of the medical history will reveal the chronological and physiological age of the patient and his or her general medical state and ambitions.

The future expectations of the patient must be respected, especially in the case of the professional or amateur athlete.

The specific details of the mechanism of injury are important, as they will suggest to the surgeon the type of force involved. The violence exerted upon both the soft and skeletal tissues will vary consid- erably depending upon the mechanism of injury, whether a motor vehicle or motorbike accident, a fall from a height, or, in an older individual, a simple fall at home.

As always, a general physical examination is essen- tial to assess the medical state of the patient.

Examination of the limb will reveal evidence of neurovascular damage and other skeletal injuries. A careful examination of the local area will reveal any lacerations at the fracture site. The degree of swelling and ecchymosis or the presence of fracture blisters will have considerable bearing on the management

decision, for an incision made through damaged skin may lead to a surgical disaster.

21.4.2 Radiological

In any articular fracture, it is imperative that a careful radiological assessment be carried out. All too often, major operative decisions are made on the basis of poor radiographs. The surgeon is then surprised during the operation by the number of fracture frag- ments present, and the injury may prove inoperable.

The number of surgical surprises must be reduced by surgeons demanding good anteroposterior, lateral, and oblique radiographs of the ankle as well as both anteroposterior and lateral tomograms. Computed tomography (CT) is invaluable in determining com- minution of the articular surface, and two-dimen- sional coronal and sagittal reconstructions can be very helpful in the overall planning of the surgical procedure (Fig. 21.9).

A careful radiographic assessment will clearly reveal the number of articular fragments and will greatly aid in the treatment decision; then, if surgery is indicated, careful preoperative planning is possible.

After this careful assessment, the surgeon must fully discuss the injury with the patient and allow him or her to participate in the treatment decision.

If the prognosis for that particular injury is poor, the patient should be so informed. If there is any chance that the surgeon may wish to do a primary ankle arthrodesis, the patient must be told of this prior to surgery; otherwise, misunderstandings (and possibly litigation) may follow.

21.5 Indications for Surgery

21.5.1 Minimal Displacement

See correction in the rate of occurrence when the preoperative assessment has indicated an undis- placed fracture, immobilization in a cast followed by a removable walking boot will lead to an acceptable result (Fig. 21.9). Patients with this kind of fracture usually have a partially intact soft tissue envelope, which favors rapid union and allows early motion.

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21.5 Indications for Surgery

21.5.2 Significant Displacement

If significant displacement is noted – that is, if large fragments of the articular surface of the joint are displaced, or the metaphysis is grossly malaligned – surgery is indicated. The amount of displacement

that is significant is controversial and depends on the multiple factors deemed the personality of the frac- ture. Thus, we may accept 2–3 mm of displacement in an elderly patient with multiple medical problems, osteopenic bone, and precarious soft tissues. Con- versely, we would not accept any articular displace- ment in a younger, active individual.

Fig. 21.9a–d. CT examination of pilon fracture. a,b This 33-year-old man was injured in a cycling accident. He sustained a severely comminuted left pilon fracture (C type) as noted on the anteroposterior (a) and lateral (b) radiographs. The plain CT (c) shows the lesion with crush of articular cartilage; this is better seen on the three-dimensional (3D) CT (d) with the talus subtracted. In that view the overall pattern of the fracture is noted, as well as the extreme comminution of the joint surface. CT with 2D 3D CT examinations are extremely helpful for operative decision-making in pilon fractures

a

c

b

d¹

d²

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21.5 Indications for Surgery 21.5.2.1

Operable

The determination of the operability of the fracture, employing logical surgical judgment, will be the next step in the decision-making process. If surgery is chosen, failure to achieve the stated goals of anatomi- cal reduction and stable internal fixation will lead to the worst of both worlds, i.e., the added trauma of the surgery inflicted upon an already severely injured extremity. Therefore, this initial decision is extremely important and must be based on a careful assessment of the radiographs, including the CT scans (axial, 2-D coronal and sagittal and even occasionally 3D reconstructions) as well as the soft tissues.

If the bone is deemed to be normal, the degree of joint comminution not excessive, and the metaphysis reconstructible, then internal fixation is indicated, but only through satisfactory soft tissue.

Immediate Surgery

If the soft tissue is adequate for a major surgical pro- cedure, then an open reduction and internal fixation should be carried out immediately. This is usually a rarity, with an example being a lower-energy injury with minimal soft tissue swelling. Paradoxically, a very severe open injury with minimal contamina- tion may present a situation wherein the exposure of the joint is “the best it will ever be.” In this rare situation, immediate internal fixation of at least the articular surface and possibly the entire fracture may be indicated. However, most patients do not fall into these situations, and soft tissues are not suitable for surgery because of the presence of marked swelling or fracture blisters (see Fig. 21.7); for these patients, surgery must be delayed.

Delayed Surgery

In most patients with a high-energy pilon fracture, surgery should be delayed. These patients should be taken to the operating room, and under general anesthesia a closed reduction should be performed, correcting any angular displacement which may be impinging on the soft tissues. If the joint is sublux- ated, it must be reduced. Most often a spanning exter- nal fixator is applied. This can be an “A-type” frame with a calcaneal transfixation pin connected to two half-pins on the tibia. The other option (especially if the fibula is intact or has been fixed) is a medial frame with half-pins in the talus and calcaneus (Fig.

21.11a,b). There are several aspects of this temporary

external fixator that must be stressed. First, the pins in the tibia must be placed well outside the fracture zone, such that future incisions and fixation will not come in contact with the pinsites that may become contaminated. Secondly, accurate placement of the talus and calcaneal pins is required to avoid neuro- logic injury to the tibial nerve (Fig. 21.11c). In some instances – depending on institution characteristics and patient status – the external fixator is applied with sterile technique and local anesthetic some place other than the operating room. The limb should be elevated on several pillows and the patient encour- aged to exercise the limb and toes. The benefits of the spanning external fixator are that the patient can go for further investigations (e.g., CT scan) on a semi-urgent basis, preoperative planning can be per- formed in a less stressful environment, and in some instances the patient can be discharged to permit the resolution of soft-tissue swelling.

In association with the frame in patients whose anterior skin is too poor for an early operative proce- dure but whose lateral skin is satisfactory, immediate open anatomical reduction of the fibula with delayed tibial fixation can be performed. This restores limb length, affords partial stability to allow the soft tis- sues to heal, and prevents the common drift to valgus of the tibia (Fig. 21.10). It is important to plan all pos- sible incisions that may be required for definitive fix- ation of the tibial injury. Almost routinely, this means performing fibular fixation through an incision made off the posterolateral border of the fibula. Occasion- ally, as a result of a large displaced posterior malleo- lus, the fibular incision is made more posteriorly.

Also, if the articular surface is undisplaced or only has a gap, percutaneous fixation of the articular frag- ments in reduced position using x-ray control may be definitive (see Fig. 21.8). Cannulated screws can be used, but are not an absolute requirement.

If a traditional open reduction is contemplated, the surgeon should wait until the skin and soft tis- sues have returned to a reasonable state before per- forming the surgical procedure on the tibia. This may require up to three weeks. If the skin and soft tissues never return to an acceptable state, then traction or external fixation must become the definitive treat- ment. In that particular situation, prior fibular fixa- tion will prove markedly advantageous.

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21.6 Surgical Technique Fig. 21.10a–e. Immediate fi bular fi xation, delayed tibial fi xation. a,b This 42-year-old workman was injured in a mining accident and sustained an open pilon fracture. On the night of the accident, a plate and a spanning external fi xator were applied. On the eleventh day after injury, open reduction and internal fi xation of the tibial fracture were performed. c The postoperative radiograph shows the excellent reconstruction of the joint surface with interfragmental screws, a small-fragment plate medially and a 2.7-mm reconstruction plate for the anterolateral fragment

21.6 Surgical Technique

21.6.1 Timing

The timing of any surgical procedure around the distal tibia must be carefully determined, depending on the particular circumstances of the case. Many questions must be answered.

Of clinical significance is whether fragments of bone are impinging on the skin and soft tissues; if so,

they must be reduced or soft tissue healing may be delayed; ulceration may even occur. If the closed soft tissue injury is assessed according to Tscherne and Gotzen (1984; see Fig. 21.4), the open reduction and internal fixation may be performed early in grade 0 or 1 injuries, but in higher grades, delay is more pru- dent. While waiting, fibular fixation is beneficial, as is traction or external fixation, outlined above. Open fractures should also be dealt with immediately. The wounds should be cleansed and débrided. Precise preoperative planning is required to safely incor- porate the wounds into the surgical incisions and to optimally place the implants.

a b

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21.6 Surgical Technique

Fig. 21.11a–c. External fi xator to maintain temporary traction in a pilon fracture. The fi xator can be placed in an “A” frame confi guration or as a medial frame. The fi bula can also be plated to restore the lateral column. The soft tissues must allow a posterolateral incision – done to allow fl exibility in incision placement for defi nitive fi xation of the pilon fracture. The pins in the tibia must be placed well out of the fracture zone – if the pins were to become infected, defi nitive fracture fi xation may be compromised. The pin in the calcaneus must be placed distal enough to prevent iatrogenic injury to the neurovascular structures at the ankle. a Classic ‘A” frame confi guration. b Medial frame with plating of the fi bula. c How not to put on an external fi xator – the tibial pins are too close to the fracture zone, and the calcaneal pin is dangerously close to the neurovascular structures.

This patient had plantar nerve dysesthesias that improved after pin removal.

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c b

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In grade 2 and 3 soft tissue injuries where massive swelling and traumatic bullae are already present, sur- gery is hazardous and must be avoided. As previously mentioned, any dislocation must be reduced, and the limb should be elevated in a bulky dressing if stable or, if unstable, with a traction pin in the os calcis, or more commonly a spanning external fixator is applied

As mentioned above, temporization with a span- ning external fixation (usually with fixation of the fibula) is indicated in most high-energy pilon fractures.

(Fig. 21.10)

21.6.2 Approach

21.6.2.1 Soft Tissue

Careful planning of the skin incision is essential. Given the choice, the favored incision runs just lateral to the anterior surface of the tibia and just medial or lateral to the tibialis anterior tendon, extending distally along its course. The choice depends on the amount and location of periarticular comminution. Care should be taken to avoid excessive disruption of the tibialis ante- rior tendon sheath (Fig. 21.12). The incisions might have to be modified depending upon the presence of lacerations or traumatized skin. Some fracture config- urations (with posteromedial and anterolateral frag- ments) can require two incisions over the respective fragments.The lateral incision for the fibular fracture should be placed posteriorly to increase the bridge between the two or three incisions (Fig. 21.12b).

Delicate handling of the skin in this area is imper- ative. It is relatively avascular, and improperly raised flaps and traumatic handling of the skin will result in necrosis with its ensuing problems. The surgeon must take great pains to be certain that the flap raised over the lower tibia is of full thickness, i.e., contains both skin and subcutaneous tissue right up to the perios- teum. If the subcutaneous layer is entered, the blood supply will be compromised and necrosis of the skin may ensue. This in turn can lead to sepsis and a disas- trous result. However, early soft tissue management with irrigation, débridement, and soft-tissue transfer – usually a free tissue transfer but occasionally a local flap – can solve this complication.

For more limited approaches to the distal tibia, only the distal end of the anterior incision is used.

Placement of the limited incision will also depend on the size and location of the fragments. The plate used to stabilize the articular segment to the meta-

diaphysis can be inserted through the distal incision, slid proximally subcutaneously above the perios- teum; stab incisions can be used to insert screws into the proximal aspect of the plate. This technique will reduce the disruption of the soft tissue envelope.

21.6.2.2 Skeletal Tissue

As in all metaphyseal fractures, especially those involving a joint surface, exposure proceeds through the fracture fragments (see Fig. 21.14a,b). This will preserve the remaining soft tissue attachments to the fracture fragments and facilitate stabilization of the comminuted metaphyseal fragments. The use of indirect reduction techniques such as the femoral distractor helps to maintain fragment viability as well as increase the visualization of the articular surface (Fig. 21.13).

Because the area in the distal tibia is such a dif- ficult area for healing due to limited blood supply, atraumatic techniques including indirect reduction

Fig. 21.12a,b. Surgical approach to fractures of the distal tibia (pilon fractures). The incision for the distal tibia should be medial or lateral to the tibialis anterior tendon as it crosses the ankle joint. This incision should be well lateral to the ante- rior subcutaneous surface of the tibia (a). The lateral incision should be posterior to the most prominent portion of the lateral malleolus and ﬁ bula, the surgeon being certain to keep as wide a bridge of skin as possible between it and the medial incision (b). On occasion three incisions may be required: pos- terolateral for the ﬁ bula, medial or posteromedial, and anterolateral (Adapted from Müller et al. 1979)

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fragment is stabilized with interfragmental lag screws and a medial buttress plate. The plate used should be low-profile and not the large fragment implants such as the spoon plate (Fig. 21.14d–h).

21.6.3.2

With Fibular Fracture

If the fibula is fractured (Fig. 21.15a), the four steps in the reconstruction are as follows:

1. Reconstruction of the fibula (Fig. 21.15b)

2. Open reduction of the tibial articular surface and metaphysis (Fig. 21.15c)

3. Cancellous bone grafting of the metaphyseal defect (Fig. 21.15c)

4. Application of a buttress plate to the anterior and/

or medial cortex of the tibia (Fig. 21.15d)

Fibular Reconstruction

The fibular reconstruction should be performed using standard AO/ASIF techniques (Fig. 21.15b).

If the fracture is transverse, an intramedullary Steinmann pin or Rush rod may be used. This has the added advantage of a short incision and minimal dis- section on the lateral side, which makes the medial approach and closure much simpler. Restoration of fibular length is essential, but less than perfect rota- tional stability of the fibula is acceptable in the pilon fracture, since stability of the tibia is restored. In the usual bi- or trimalleolar ankle fracture, it is imperative to achieve rotational stability of the fibula, and there- fore intramedullary devices in the fibula are contra- indicated. However, in the particular type of fracture with which we are dealing here, i.e., the pilon fracture, intramedullary devices in the fibula are ideal if the fibular fracture is transverse and not comminuted.

If the fibula is comminuted, the fracture should be fixed with interfragmental compression screws if pos- sible and a 3.5-mm compression plate as a neutraliza- tion. The benefit of the larger plate is restoration of the lateral column of the ankle. If the fibula is grossly comminuted, it is extremely important to be certain that full length is restored to the fibula. The fibula is connected to the lateral articular fragment of the tibia;

therefore, its proper length is the key to the reduction of this tibial articular surface. Shortening of the fibula will cause malreduction of the major tibial fracture. In this instance a bridge-plating technique is utilized.

In some instances, there may be so much com- minution of the fibula that primary fixation of this bone is impossible. In those circumstances, articu- lar reconstruction of the tibia should proceed first,

Fig. 21.13. Indirect reduction using the distractor and tem- porary ﬁ xation of the joint fragments with Kirschner wires.

Internal ﬁ xation then can be applied to the ﬁ bula. (From Müller et al. 1991)

are essential to achieve satisfactory results. In this area, clearly biology is more important than biome- chanics.

21.6.3 Technique of Internal Fixation

21.6.3.1

Without Fibular Fracture

If the fibula is intact, lateral stability of the ankle mortise is maintained. Usually, however, the tibial fracture exhibits comminution and impaction of the joint surface (see Fig. 21.2c).

A large intact fragment usually remains with the fibula and is used as a guide to the articular recon- struction. The large medial vertical fragment may be carefully retracted with a rake retractor or a lami- nar spreader, thus exposing the articular surface (Fig. 21.14a,b). All soft tissue attachments to this fragment must be retained. If a central depressed articular fragment is found, it must be restored to its anatomical position and provisionally fixed with Kirschner wires (1.6–2.0 mm) (Fig. 21.14b). A bone graft – a cancellous autograft, substitute or combina- tion – will fill the void. The medial vertical fracture is reduced, thus “closing the book” (Fig. 21.14c). This type of fracture is akin to the usual type of depressed proximal lateral plateau fracture. The large medial

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a b

c

e

d

f

g h

Fig. 21.14a–h. Technique of open reduction and internal fi xation in a pilon fracture with an intact fi bula. Since the fi bula is intact, lateral stability of the ankle mortise is maintained. A large tibial fragment usually remains with the fi bula and is used as a guide to articular reconstruction. a The large medial vertical fragment is retracted with a rake retractor. Working through the fracture in order not to destroy soft tissue, the articular fragments are restored to the anatomical position and provisionally fi xed with 2-mm Kirschner wires. b Atraumatic indirect reduction techniques must be used. c Any gap is fi lled with cancellous bone to hold the articular fragments in place. d The tibia is then buttressed with a medial and/or anterior buttress plate and lag screws as indicated. e,f Anteroposterior, lateral radiographs and axial CT of a 23-year-old man involved in a motor vehicle accident. Note the intact fi bula and the articular fragmentation. g,h Reconstruction by the above method using temporization?? with a spanning external fi xator, followed by open- reduction internal fi xation

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Fig. 21.15a–e. Pilon fracture reconstruc- tion with fi bular fracture. a Pilon fracture with intra-articular comminution and fi bular fracture. b Step 1: reconstruction of the fi bula by either an intramedullary rod or a 3.5-mm LC-DCP plate (usual), or a one-third semitubular plate. c Steps 2 and 3: reconstruction of the articular surface of the distal tibia and provi- sional fi xation with Kirschner wires. The

metaphysis is reduced with the atraumatic, indirect techniques. The resultant gap is fi lled with bone graft substitute. d Step 4: application of a medial buttress plate (T plate). (Adapted from Müller et al. 1979). e Clinical case from 21.11c. The poorly applied external fi xator was removed and the pin sites were allowed to heal. Coronal and sagittal 2D CT reconstructions showing extensive communition of the articular surface. Delayed internal fi xation using a 3.5 locking plate on the fi bula and a medial locking plate. In addition, a 1/4 tubular plate fashioned into a „hook plate“ was used to buttress an anterolateral fragment

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and fixation of the fibula can be undertaken after- wards if technically possible. However, failure to reconstruct the fibula at all is a major error in judg- ment and may jeopardize the tibial reconstruction, as the tendency of the ankle to drift into valgus will be difficult to overcome. Stabilization of the fibula is therefore an essential part of the treatment. The one exception to this rule would be the instance when ring fixation is utilized and the fibula and tibial metaphysis are both grossly comminuted. In this instance, rings above and below the zone of fracture comminution provide stability, and some shorten- ing can be allowed.

Articular Reconstruction of the Tibia

After fixation of the fibula, articular reconstruction should proceed in a logical fashion. The articular surface should usually be reduced first. The key to the articular reconstruction is the lateral fragment, which should be in the anatomically correct posi- tion if connected by the inferior tibiofibular liga- ment to the already anatomically fixed fibula. Each of the major fragments should be reduced and care- fully fixed with Kirschner wires. If only major frag- ments are involved, the reduction is relatively easy and should be anatomical (Fig. 21.14).

If gross comminution of the metaphysis is present, the surgeon should first focus his or her attention on an accurate reconstruction of the articular surface.

The articular fragments should be provisionally fixed with 1.25- or 1.6-mm Kirschner wires and then replaced with small-fragment screws – either 3.5- or 2.7-mm cortical screws, depending on the size of the fragments.

Occasionally, small, anterior fragments can be but- tressed with plates, or even with use of a “spring plate.”

Following fixation of the articular surface, the axial alignment of the metaphysis must be obtained.

It is essential that the fragments retain their soft tissue and vascularity; therefore, indirect techniques must be used. Several techniques are possible, includ- ing a skeletal distractor, external fixation, or the use of a plate connected to the articular fragment and a distraction device (Fig. 21.13).

In very rare instances of isolated articular impac- tion, arthroscopic-assisted elevation and percutane- ous screw fixation can be undertaken (Fig. 21.18).

Void fillers

A cancellous (either autogenous or allograft) or syn- thetic bone graft can be used to fill the resulting

defect in the metaphyseal area. The graft should be fully impacted to restore stability to the distal frag- ment (see Fig. 21.15c). Small fragments of articular cartilage which have not been fixed with Kirschner wires and are not small enough to discard may be held in place between the cancellous bone graft and the dome of the talus. Their stability must be ensured, so that they do not fall out into the joint and act as a loose body.

Medial Tibial Cortex Buttress Plate

To ensure stabilization of the reduced articular segment of the diaphyseal segment, a plate is applied either anteriorly or medially, depending upon the area of comminution (see Figs. 21.6, 21.14, 21.15). The medial buttress plate may be either a conventional or locked plate. Anatomic precontoured or conventional 3.5-mm compression plates can be utilized (see Figs.

21.14, 21.15). The weak cloverleaf plate has been replaced by anatomic plates that recently became available in locking modalities. If the comminu- tion is anterior, the anterior buttress plate will give far better fixation and is recommended (Fig. 21.14).

These general principles are well illustrated in Figs.

21.14, 21.15.

If it becomes obvious to the surgeon after the start of the surgical procedure that the bone is too weak to hold a screw, the situation may be improved by using the newer locking plates.

The spoon is bulky and should not be used (Fig.

21.16).

Fig. 21.16. Spoon plate as an anterior buttress plate. This plate should never be used; rather, a lower proﬁ le implant as one may use in the distal radius should be used

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Fig. 21.17. a–i Reduction and fi xation techniques with poor soft tissues. a If the distal fi bular tissues allow and the fi bula is fractured, anatomic open reduction and external fi xation of the fi bula should proceed fi rst. b Using traction techniques to reduce the fracture (see Fig. 21.24), or through a limited anterior approach using a periosteal elevator to reduce the articu-

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d

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21.6.4 Wound Closure

If incisions can be closed without tension, this should be done, primarily over suction drains. Very commonly, however, suturing both incisions will cause undue tension on one or the other wound.

When this is the case, it is far better to leave a portion of one wound open than to close it under tension, since this will undoubtedly result in skin necrosis. It is best to close the tibial wound because of its proximity to the anterior tibial tendon, the subcutaneous border of the tibia, and the major metal implant. The lateral wound may be left open along all or a part of its length. If the lateral skin incision has been correctly made, posterior to the

lar fragment, Kirchner wires are inserted. If the articular fragments are reduced, cannulated screws are inserted over the Kirschner wires for ﬁ xation.

Also, a bone graft may be inserted through this approach. c Other fragments may be held using the above wires or other fi ne wires, attached to a ring fi xator for axial stability (d–f). The goal is to insert at least three wires into the distal segment, with the fi rst being the “reference “ wire inserted parallel to the joint. The next two wires are posterolateral to anteromedial, coming out medial to the tibialis anterior tendon, and posteromedial to anterolateral, coming out just anterior to the fi bula, or through the fi bula. g–i Minimal internal fi xation and ring

„hybred frame“ fi xator in polytrauma with poor soft tissues. This 40-year-old woman was involved in a motor vehicle accident. She sustained a pelvic ring injury, a segmental femur fracture, a fracture of her right tibia, and an open pilon fracture. Because of her polytrauma and poor soft tissues, it was elected to treat the left tibial fractures with minimal internal fi xation and a ring fi xator. The severe comminution of the ankle joint is noted in the radiograph (g), and after fi bular fi xation and spanning external fi xation in the CT scan (h). The joint surface was anatomically reduced and fi xed with screws. (i). The fi nal position, including the ring fi xator, is noted on the radiograph (courtesy of Mark Macleod)

fibula, then the fibular plate will be covered by the skin flap and few problems will ensue. This lateral wound may then be closed on the fifth to tenth postoperative day with fine sutures or skin tapes.

If closure is not possible, this area is amenable to split-thickness skin grafting over the peroneus musculature.

Note: in this area, the surgeon should not attempt to close the skin under tension. The skin in this area may be so traumatized that the entire flap may be rendered avascular and become necrotic, causing a major surgical disaster (Fig. 21.7d). It is far better to leave one wound open and close it secondarily than to undertake ill-advised primary plastic pro- cedures.

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21.6.5 Postoperative Care

21.6.5.1 Early

In the immediate postoperative period, a bulky dress- ing and posterior slab are applied to the ankle in the neutral position, and the extremity is elevated to reduce swelling.

Fig. 21.18a–h. Arthroscopic-assisted ﬁ xation of a pilon fracture. The radio- graphs show a joint depression fracture involving a small portion of the articular surface of the distal tibia. Arthroscopic-assisted elevation and ﬁ xation. The overall result was excellent. This technique is reserved for a very small subset of pilon fractures such as the case shown (courtesy of Ned Amendola)

The course of the patient’s postoperative care will depend upon the surgeon’s honest appraisal of the stability achieved by surgery. If the bone qual- ity is good and the surgeon has been able to achieve stable internal fixation, then the dressing and splint are removed on the second postoperative day, and motion is encouraged. The stabilized fracture is rela- tively painless, many patients being able to move their ankle comfortably as early as the second postopera- tive day. To prevent a troublesome equinus deformity

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21.7 Common Pitfalls of Treatment

from developing, the ankle must be maintained in a right-angled splint when the patient is not exercising;

once an equinus deformity has developed, attempts at correction by rehabilitation may be tedious and prolonged, and they are often unsuccessful.

If the surgeon is in doubt about the stability of the fracture at the conclusion of the operation, a span- ning external fixator can be left in place or applied.

Preservation of the anatomical reduction is essential to the long-term result and should not be compro- mised by early motion.

21.6.5.2 Late

The patient must be carefully monitored clinically and radiologically. A removable walking boot can used within 4 weeks if stability is satisfactory, or on a delayed basis at 6–8 weeks if there is concern regarding compliance of the patient or stability of the fixation construct. This allows the patient to bear partial weight with the aid of crutches. The splint should be regularly removed for ankle exercises. If the patient has no pain and the radiograph indicates no problems with the implant, bone union is usually complete at 10–16 weeks, and full weight bearing may be resumed. This will, of course, depend upon other factors, such as the degree of comminution, the size and incorporation of the bone graft, and the state of the soft tissues.

21.7 Common Pitfalls of Treatment

Since the pilon or distal tibial metaphyseal fracture is fraught with major problems in management, it seems relevant to review many of the common pitfalls we have encountered in our practice when the prin- ciples stated above have been compromised.

21.7.1 Poor Decision-Making

Poor decision-making is probably the most common cause of grief with this fracture. In some cases, oper- able fractures are treated nonoperatively, with poor results, while in others shattered fractures, obviously nonoperable, are treated operatively, with a similar outcome.

21.7.2 Operating Through Poor Skin

Operating through severely traumatized skin with fracture blisters constitutes a great error of judgment and often leads to a major disaster, occasionally even an amputation.

The use of the staged approach with the use of the spanning external fixator with or without fibular fix- ation will lead to fewer soft-tissue complications.

21.7.3 Technical Difficulties with the Fibula

If the fibula length is not restored, the ankle will tend to drift into valgus (Fig. 21.21), while if the normal valgus curve of the fibula is not restored, the ankle will assume to varus position (Fig. 21.22). The result- ing axial malalignment will cause difficulty with the gait and increase the risk of degenerative arthritis developing in the ankle.

21.7.4 Technical Difficulties with the Tibial Fracture Previously there was a tendency among surgeons to fix the articular position of the joint and ignore the metaphyseal crush, i.e., to do only one half of the job. This is a common error, usually leading to axial malalignment and a poor final result.

Furthermore, failure to fill the large metaphyseal gap with bone graft may allow the articular fracture to displace, with adverse late consequences.

At this time, attempts are usually made to fix the metaphysis, but unfortunately the methods used often do not reflect the newer techniques of biologic fixation, which are extremely important in this anatomic area.

21.7.5 Poor Postoperative Care

Over-optimistic assessment of the operative stabiliza- tion and the state of the bone often leads the surgeon to institute early motion of the ankle. If the assessment was wrong, the inevitable result will be collapse of the fixation and loss of the anatomical reduction.

A major cause of grief is failure to splint the ankle at postoperatively. The resulting equinus deformity may be difficult to deal with. There is no excuse for this preventable complication.

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21.8 Late Rconstruction: Malunion

21.8 Late Reconstruction: Malunion

If the patient has continuing pain following union of a pilon fracture, careful clinical and radiographic assessment is required. This will determine whether

Fig. 21.19a–f. The use of a spanning external fi xator, fi bular plating, and percutaneous fi xation of the articular surface leading to a varus malunion. Anteroposterior and lateral radiographs of a 24-year-old female with a pilon fracture after a fall from the second story of a burning building. Initial radiographs with a spanning external fi xator. Radiographs following fi bular plating, fi xation of the joint demonstrating mild varus malposition. At 3 months, posterolateral iliac crest bone grafting and removal of the external fi xator. Radiographs showing varus malunion requiring an oblique osteotomy and plate fi xation. The fi nal result was good, but the patient has complaints consistent with degenerative arthritis.

a b c

d e f

the articular cartilage of the ankle joint has been so damaged that arthrodesis or arthroplasty of the ankle is the only alternative. In some instances the presence of osteochondral damage can be determined with CT scans. If present, this can benefit from an ankle arthros- copy for débridement. If the articular surface is satis-