2 Intra-articular Fractures

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2.1 Introduction

2 Intra-articular Fractures

J. Schatzker

2.1 Introduction

Intra-articular fractures may result in stiffness, deformity, pain, and posttraumatic arthritis. In order to avoid deformity and stiffness it is necessary to secure an anatomical reduction of the articu- lar surface, restore joint stability and normal axial alignment, and begin early motion. Sir John Charn- ley stated that “perfect anatomical restoration and perfect freedom of joint movement can be obtained simultaneously only by internal fixation” (Charnley 1961). At the time that Charnley wrote The Closed Treatment of Common Fractures, sufficiently stable and sufficiently strong internal fixation that would allow early motion was not available. Indeed, the results of internal fixation were so discouraging because of stiffness, deformity, delayed union, and nonunion that Charnley argued in favor of nonop- erative treatment. His sentiments were soon echoed by Stewart et al. (1966) and Neer et al. (1967), who published the results of treatment of a major intra- articular fracture, the supracondylar fracture of the femur in the adult. Even with limited criteria of excellence which today would be thought unaccept- able, such as the acceptance of 70° knee flexion as satisfactory (Neer et al. 1967), both groups found the results of surgery to yield just over 50% acceptable results. Stewart et al. went on to state that it was the added trauma of surgery and the presence of metal in periarticular locations which directly con- tributed to stiffness. A review of the publications of these authors and others makes it evident that the techniques of internal fixation then in existence and the implants available were totally inadequate. Suf- ficient stability could never be achieved to permit early pain-free motion. If motion was permitted, not only did pain inhibit motion and result in stiff- ness, but displacement and loss of reduction were also very common. To prevent displacement, inter- nal fixation was combined with plaster fixation, and this invariably resulted in permanent stiffness.

The publication of the Swiss AO/ASIF group in 1970 (Wenzl et al. 1970), our own review (Schatzker et al.

1974), and other reviews (Mize et al. 1982; Olerud 1972;

Schatzker and Lampert 1979) of results of treatment of major intra-articular injuries utilizing the AO meth- ods and implants indicated strongly that with the new principles, methods, and implants, stable fixation and early motion after internal fixation was an attainable surgical goal, and that fractures – particularly intra- articular fractures – so treated did amazingly well.

The AO/ASIF methods of open reduction and internal fixation made strong, stable, and lasting fixa- tion possible. Despite early, unprotected mobilization, accurate anatomical reduction of the joint and of the metaphyseal fractures could be maintained. Indeed, the patients were so completely free of pain that it was difficult to persuade them not to bear full weight and resume full function before union was complete.

The large number of patients who were treated non- operatively (Schatzker et al. 1974, 1979) permitted us to make certain observations which we consider invalu- able lessons in articular fracture treatment. Patients whose intra-articular fractures were immobilized in plaster for 1 month or longer ended with permanent marked stiffness of these joints. Patients with similar fractures which were treated by open reduction and internal fixation, but whose joints were subsequently immobilized in plaster, ended with far greater stiffness.

Patients whose intra-articular fractures were treated by traction and early motion ended with varying degrees of joint incongruity, but invariably with a much better range of motion. This allowed us to formulate a prin- ciple of intra-articular fracture treatment: Displaced intra-articular fractures that are not treated by open reduction and stable internal fixation should be treated by traction and early motion.

Fractures that were treated by manipulation and traction often showed persistent displacement of some fragments. At surgery these fragments were always found to be firmly impacted into the metaphy- seal cancellous bone and could be dislodged only by direct surgical manipulation. This permitted us to formulate the second principle of treatment: Intra-

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2.1 Introduction

articular fragments which do not reduce as a result of closed manipulation and traction are impacted and will not reduce as a result of further manipulation or traction.

A number of cases of patients with intra-articu- lar fractures which were initially treated closed but eventually operated on led to one further important observation: Major intra-articular depressions do not fill with fibrocartilage to restore joint congruity and instability. If a joint is unstable because of major joint depression, the instability will become perma- nent unless the fragment is reduced surgically and held in position until union occurs.

Pauwels (1961) postulated that in a normal joint there is a state of equilibrium between articular car- tilage regeneration and articular cartilage destruc- tion. Furthermore, he felt that articular cartilage wear occurred constantly, as a result of stress. As stress is the result of force acting on a specific sur- face area, that is, S=F/A, it becomes clear that stress can be increased and the equilibrium tipped in favor of joint destruction either by decreasing the surface area of contact (A) or by increasing the force (F), or by both. F is increased above its physiologic level by axial overload, the result of a metaphyseal or diaphy- seal deformity.

A consideration of the above led us to an inescap- able conclusion: Anatomical reduction of the joint is essential to restore joint congruity and increase the surface area of contact to the maximum possible, and metaphyseal and diaphyseal deformity must be cor- rected to prevent axial overload (Fig. 2.1). Both the joint congruity and axial alignment are important in restoring joint stability.

These are similar to the principles of intra-articu- lar fracture care enunciated by the AO (Müller et al.

1979), and we fully agree with them. The therapeutic validity of these principles is confirmed by the favor- able results of modern operative treatment of intra- articular fractures.

What about articular cartilage damage sustained at the time of injury and the possibility of articular cartilage regeneration? In an elegant experiment, Mitchell and Shepard (1980) studied the effects of the accuracy of reduction and stable fixation. With the aid of histological methods and electron microscopy, they were able to show that anatomical reduction and stable fixation of intra-articular fragments by means of compression resulted in articular cartilage regen- eration.

Salter et al. (1980, 1986) studied experimentally and clinically the effects of continuous passive motion on articular cartilage healing and regeneration. They demonstrated very convincingly that continuous passive motion stimulated both processes.

More recent investigations into step-off defects (Llinas 1993, 1994) have delineated the limits of posi- tive step-off deformities, which should not exceed the thickness of the articular cartilage. These studies have also confirmed the limited ability of articular carti- lage to remodel. They have further demonstrated the danger of a positive step-off deformity to the oppos- ing articular surface in causing rapid degenerative change.

Magnetic resonance imaging (MRI) investiga- tion of closed joint injuries has revealed “bruising’’

of the subchondral bone and has allowed a correla- tion between certain MRI patterns of bruising and subsequent osteochondral fragmentation and the formation of articular defects (Vellet et al. 1991).

Similar damage to articular cartilage and subjacent bone must also occur in association with fractures (Dickson et al. 2002). This points to the shortcom- ings of visual evaluation of articular cartilage injury and indicates why caution should be exercised in the prognosis of articular injuries, since some aspects of the injury may escape detection and are not influ- enced by treatment.

These experimental and clinical studies permit us to enunciate the principles of intra-articular fracture treatment as follows:

1. Immobilization of intra-articular fractures results in joint stiffness.

2. Immobilization of articular fractures treated by open reduction and internal fixation results in much greater stiffness.

Fig. 2.1. Anatomical reduction of the joint and correction of metaphyseal and diaphyseal deformity greatly reduces the stress on articular cartilage

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2.2 Clinical Aspects

3. Depressed articular fragments which do not reduce as a result of closed manipulation and traction are impacted and will not reduce by closed means.

4. Major articular depressions do not fill with fibro- cartilage, and the instability that results from their displacement is permanent.

5. Anatomical reduction and stable fixation of articular fragments is necessary to restore joint congruity.

6. Metaphyseal defects must be bone-grafted to prevent articular fragment redisplacement.

7. Metaphyseal and diaphyseal displacement must be reduced to prevent joint overload.

8. Joint congruity and correction of axial deformity is necessary to restore joint stability

9. Immediate motion is necessary to prevent joint stiffness and to ensure articular cartilage healing and recovery. This requires stable internal fixa- tion.

2.2 Clinical Aspects

The clinical aspects of intra-articular fractures are important in the decision-making process regarding the best mode of treatment for a particular injury.

We emphasize repeatedly in this book the concept of the “personality” of the fracture. In order to define the personality, we must know not only such obvious

factors as the violence involved in the injury, but also the patient’s age, occupation, athletic pursuits, expec- tations of treatment, and similar details.

2.2.1 Physical Examination

Although radiological examination is indispensable in defining the fracture pattern, it does not shed light on the soft tissue components of the injury. Tender- ness over the course of a ligament or its insertion may be the only available clue to a ligament disrup- tion. Similarly, the presence of an open fracture, a neurological deficit, a compartment syndrome, or a vascular lesion is best established by physical exami- nation.

2.2.2 Radiological Evaluation

An anterioposterior and a lateral radiograph are frequently insufficient to define precisely the pat- tern of injury (Fig. 2.2). We have found that oblique projections, as well as stress X-rays when indi- cated, add greatly to the definition of an injury.

Often intra-articular detail is obscured because of distortion and overlap of fragments (Fig. 2.3).

Plain tomography will help to define the detailed outline of intra-articular and metaphyseal frag- ments (Fig. 2.4), which will facilitate classification of the injury and determination of its prognosis

Fig. 2.2a–d. Tibial plateau fracture roentgenograms. a Anteroposterior. b Oblique. c Oblique. d Lateral. Note particularly on the two oblique projections (b, c) the marked improvement in the deﬁ nition of the lateral plateau comminution and depression

a b c d

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2.2 Clinical Aspects

and thus guide its treatment. Most centers today have abandoned plain tomography and are using computerized axial tomography with coronal and axial reformations instead. Computed tomography (CT) is much more useful than tomography, and has been invaluable in some complex fractures such as acetabular injuries, pilon fractures, frac- tures around the knee, and some shoulder injuries (Fig. 2.5).

We use CT routinely in the evaluation of all com- plex fractures. Its frontal and sagittal reconstruc- tions give all the information that can be gleaned from tomography. In addition, it shows the surgeon the cross-sectional anatomy of the fracture, indicates clearly the planes of the fracture lines, and often discloses unsuspected fracture lines. Thus it is an indispensable tool in preoperative planning and in classification of the fracture. It is also very useful if the surgeon is planning to insert some of the fixation screws percutaneously.

2.3 Surgery

2.3.1 Timing

The only intra-articular injuries which demand immediate surgical intervention are open frac- tures, irreducible fracture dislocations, fracture dislocations associated with neurological injuries where pressure of bone on neurological structures prejudices function, articular fractures associated with vascular injuries, and articular fractures associated with compartment syndromes. An intra-articular fracture is a complex injury, with the fracture only one part of it. From the perspec-

Fig. 2.3. a Anteroposterior roentgenogram of a supracondylar fracture of the humerus. The details of the fracture are almost completely obscured. b Anteroposterior roentgenogram of the opposite, uninvolved elbow to be used as template for preoperative planning

a b

Fig. 2.5. Computed tomography (CT) scan of a posterior fracture – dislocation of the hip. Note the large intra-articular fragment that was not evident on a plain roentgenogram or plain tomography

Fig. 2.4. Anteroposterior tomogram adds greatly to the pre- cise deﬁ nition of the injury

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2.3 Surgery

tive of immediate or early complications the soft tissue component is far more important. Complex intra-articular fractures, particularly those result- ing from high-energy axial compressive forces, dis- sipate much of the force through their soft tissue envelope. Early surgery through such traumatized soft tissue almost guarantees a high incidence of wound healing problems and infection. Thus delayed surgery until such time as the soft tissue envelope has recovered is the rule. This may take anywhere from a few days to as long as two to three weeks. While surgery is delayed one should not simply splint these injuries but restore length and alignment. This not only reduces pain and leads to more rapid resolution of the swelling, but also makes the delayed reconstruction much easier. To restore length one requires traction. In the past we used to place such injuries in traction. Today with the great pressure regarding availability of hospital beds, prolonged hospitalization prior to surgery is not possible. Thus whenever possible we have been placing these patients in bridging external fixation.

This has allowed restoration of length and through ligamentotaxis varying degrees of reduction of the fracture. The patients are taught pin care and are discharged home until such time as they can be readmitted for surgery. One further advantage of the partial reduction in traction is that it greatly facilitates the imaging and detailed analysis of the fractures and allows more precise pre-operative planning, particularly with respect to minimally invasive techniques of fixation.

Our recommendations to delay immediate recon- struction of complex articular fractures have been reinforced by the experience of other surgeons (Marsh et al. 1994; Stamer et al. 1994; Keppler et al. 1994). The complications encountered as result of early recon- struction of high-velocity articular fractures, partic- ularly of subcutaneous joints such as the tibial pla- fond and the tibial plateau, have led to major changes in the timing of reconstruction, in the exposure tech- niques, and in the methods of fixation. We recom- mend securing reduction of the articular surfaces as early as possible if that can be achieved with minimal exposure and fixation. Here percutaneous reduction techniques and cannulated screws find their applica- tion. This is done of course once the external fixator has been applied and the fracture reduced as much as possible by ligamentotaxis. We recommend the early reduction of articular surfaces because articular fractures unite rapidly and defy attempts to perform late reduction or joint reconstruction. The timing of the reconstruction of the injury’s metaphyseal com- ponent is based on the severity of injury to the soft tissue envelope. In high-velocity injuries we generally tend to delay the metaphyseal reconstruction, and maintain length and alignment of the metaphysis by either traction or external fixation. The current guid- ing principle in the internal fixation of articular inju- ries is the preservation of the blood supply to the soft tissues and to all the bony fragments. Thus not only is the metaphyseal reconstruction carefully staged, but we also rely on techniques of indirect reduction, on the percutaneous insertion of lag screws, and,

Fig. 2.6. Florid ossifying myositis (arrow) particularly in front of the elbow – a frequent complica- tion of delayed surgery around the elbow

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2.3 Surgery

where indicated, on the buttressing of these fractures in hybrid frames in order to preserve the viability of tissues as much as possible.

In certain areas, particularly the elbow and the hip, we have found that a delay is often associated with a higher incidence of myositis ossificans (Fig. 2.6) which in itself may become a problem. However, we would rather risk the danger of periarticular ossifica- tion than the ravages of soft tissue breakdown and infection.

2.3.2 Approach and Technique

Once the personality of the fracture has been defined by painstaking clinical and radiological investigation, it is necessary to make a careful preoperative plan of the surgery. This includes a plan of the surgical approach as well as a detailed plan of the internal fixation and any bone grafting required.

The exposure of the joint must be atraumatic, and yet it must be sufficient so that all the components of the injury can be accessible to manipulation and fixation. (For detailed descriptions of such expo- sures, please refer to the chapters on the specific joint fractures.)

The surgical reconstruction of the joint begins with an anatomical reduction of the articular sur- face. This often requires that depressed portions of the articular cartilage be elevated from their impacted position in the metaphysis. This is best done by elevating the depressed fragments together with the impacted metaphyseal cancellous bone.

Once elevated, the fragments must be held provi- sionally in their reduced positions using Kirschner wires. It is then necessary to bone-graft the metaph- yseal defect that is invariably created when the articular fragments are disimpacted and elevated.

Although some authors have described the use of cortical struts to hold up the articular surface, we prefer autogenous cancellous bone, which we com- pact with a bone punch. This allows good filling of the defects and helps to maintain the articular reduction. In older patients we have used allograft cancellous bone since donor sites such as the iliac crest in elderly patients do not yield a great deal of bone. Allograft cancellous bone incorporates well in well-vascularized cancellous areas, and patients so treated have done well. More recently more and more surgeons have been experimenting favorably with bone substitutes, particularly particulate mate- rial with or without bone morphogenic substances.

They make the strong argument that donor site morbidity is more common than generally admit- ted. In considering our preference for autogenous cancellous bone, particularly in young patients, we would like to remind the reader of the potential of disease transmission with the use of allografts and the great cost of the yet not fully proven substitute materials. Autogenous cancellous bone is still the gold standard in these situations. Next in order of importance is a careful reduction of the metaphy- seal and diaphyseal components of the fracture.

Once the fractures are reduced, we secure fixa- tion of the articular components by means of lag screws. These lag screws should not be inserted too close to the subchondral bone, because they lead to its stiffening and to possible chondroly- sis (Manley and Schatzker 1982). The metaphysis must be buttressed to prevent axial overload, and the diaphyseal components must be fixed so that early motion can be started. Prior to closure, cer- tain intra-articular structures such as the menisci of the knee should be repaired if torn or peripher- ally detached. In-substance lesions of the cruciate ligaments are not repaired primarily nor substi- tuted, as such repairs require postoperative immo- bilization, which we like to avoid. The only cruciate lesions we repair immediately are avulsions of the anterior or posterior cruciate ligament with a piece of bone; these can be fixed with lag screws or wire loops with sufficient stability to allow immediate mobilization. Any other cruciate deficiencies are repaired at a later stage, if indicated. This policy has allowed us to concentrate on the mobilization of the joints, which we feel is far more important than early anteroposterior stability. This policy does not, however, apply to lateral stability. All collateral liga- ments are carefully repaired at the time of the ini- tial surgery; collateral repair does not prevent early mobilization of the joint.

As already alluded to, the timing of the recon- struction of the metaphyseal component is fre- quently delayed in order not to prejudice the soft tissue envelope. This does not mean that a pri- mary reconstruction cannot be carried out, but caution is the key. It is best to err on the side of delay rather than haste. Once the reconstruction is undertaken, all efforts are undertaken to minimize trauma in order to preserve the blood supply to the soft tissue and bone. Thus techniques of indirect reduction are employed together with minimal exposure and the use of percutaneous lag screws where indicated. Most buttressing is still accom- plished with plates, but where immediate surgery

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2.5 Late Intra-articular Reconstructions

must be undertaken, such as in open fractures or in closed fractures complicated by a vascular injury or an acute compartment syndrome, we rely on hybrid frames rather than plates. If the epiphyseal fragment is too small for a hybrid frame, then we are prepared to bridge the joint with an external fixateur. Necrosis of the soft tissue envelope is a preventable disaster. Some loss of motion is pref- erable to infection. If early operation is essential, the skin should never be closed under tension. We like to close the synovium and capsule to prevent desiccation of the articular cartilage and to cover any exposed tendon or nerve. The remainder of the wound is left open and closed secondarily 5 or 6 days later. If early closure with local tissue is not possible, then a local muscle flap or free vascular- ized pedicle graft must be considered to prevent desiccation and death of sensitive tissues and the inevitable sepsis which follows.

2.4 Postoperative Care

The experiments of Salter et al. (1980) and Mitchell and Shepard (1980) have underlined the importance of early motion. Our clinical experience, as well as that of many other investigators, bears this out. After their reconstruction, most major intra-articular injuries are placed on a continuous passive motion machine; pas- sive mobilization is started in the recovery room and is continued for 5–7 days. In late joint reconstructions this may be continued for up to 3 or 4 weeks. Although the general enthusiasm for continuous passive motion (CPM) has waned, we still feel that it is a most worthy adjunct in the management of serious major intra- articular injuries.

It must be remembered that mobilization and its benefits need to be in balance with the degree of stability obtained at the time of surgery. At times, the degree of stability of the internal fixation is insufficient to permit unprotected mobilization. In these instances we have combined internal fixation with fracture bracing. The fracture brace can be applied on the first day or two without jeopardiz- ing the internal fixation or wound care. Similarly, it must be remembered that in at least 25%–30% of cases, major intra-articular fractures, particularly around the knee, are associated with major liga- mentous disruptions, which must be repaired at the time of the initial surgery. The usual practice is to protect any ligamentous repair in plaster. As we have

already pointed out, intra-articular fracture repair combined with plaster immobilization results in an unacceptable degree of stiffness. Therefore, we have always managed these combined injuries and repairs by protecting the ligamentous reconstruc- tions by immediate fracture bracing and then carry- ing on with the usual mobilization on a continuous passive motion machine. Because in-substance cru- ciate ligament reconstructions require the surgeon to limit the excursion of the knee, we have deferred such reconstructions, but have always repaired col- lateral ligaments and cruciate avulsions with bone.

Late cruciate insufficiency has been dealt with when necessary once the joint has been fully rehabilitated.

Joint stiffness is one complication that must be avoided at all costs.

2.5 Late Intra-articular Reconstructions

Late intra-articular deformities arise (a) as a result of failed nonoperative treatment, (b) because of incomplete surgical reduction of the fracture, or (c) because of loss of position due to unstable fixation. Such articular deformities have usually been considered as permanent and not amenable to any surgical reconstruction. We have subjected many such intra-articular deformities to late intra- articular reconstruction, at varying intervals from the time of injury (Figs. 2.7–2.10). This has often required intra-articular osteotomies with meticu- lous excision of the fibrocartilage from the joint and of the callus from the metaphysis, in order to redefine the original fragments and permit an anatomical reconstruction. We have also treated a number of intra-articular nonunions. The princi- ple followed with these, as with the malunions, has been meticulous reconstruction of the joint, stable fixation of the joint and of the metaphyseal compo- nent with bone grafting where necessary, arthroly- sis and soft tissue mobilization periarticularly to regain a satisfactory range of motion, and then mobilization of the joint on a continuous passive motion machine. Although we have never managed to achieve a return to a perfectly normal degree of joint function, we have been impressed with the successes attained and feel that unless there is evidence of serious post-traumatic arthritis, a late joint reconstruction should be undertaken if it is at all technically feasible. This is preferable to joint arthroplasty or arthrodesis.

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Fig. 2.7. a An intra-articular pilon fracture at 6 weeks after surgery. A number of sur- gical principles have been violated. The ﬁ bula was not reduced, the metaphysis was not bone-grafted, and the lesion was not properly buttressed. b Note the excellent correction of the deformity achieved by reduction of the ﬁ bula, by bone grafting of the metaphyseal defect created once the valgus was corrected, and by proper buttressing of the metaphysis

a

b

Fig. 2.8. a Serious malreduction of a difﬁ cult tibial plateau fracture. b Stability was restored by an intra-articular wedge excision of the depressed area. This allowed us to narrow the lateral plateau and reduce the remaining intact portion, which carried the meniscus under the lateral femoral condyle

a

b

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2.5 Late Intra-articular Reconstructions Fig. 2.9. a,b Malunion of the lateral femoral condyle and fracture of the cancellous screw. Note the double contour of the lateral femoral condyle, best seen in b.

This malunion distorted the intercondylar groove and markedly restricted knee motion. c An intra-articular osteotomy was carried out. The excessive ﬁ brocarti- lage and all callus were carefully excised, recreating the original fracture fragment. This allowed an anatomical reduction of the joint. Note the unorthodox position of a buttress plate on the posterolateral aspects of the distal femoral metaphysis. Anatomi- cal reduction and stable ﬁ xation led to an excellent recovery of the joint

b a

c

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Fig. 2.10. a A 2-year-old nonunion of the lateral femoral condyle in an 18-year-old boy. c Note the excellent correction of the valgus deformity at 3 years after surgery, with union and an excellent preservation of joint function, despite the intra-articular step clearly evident in b soon after correc- tive surgery

a

c b

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2.1 Introduction

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