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Journal of the American Academy of Orthopaedic Surgeons 176 Nonarticular proximal tibia fractures should be distinguished from more distal injuries. Higher rates of malunion and increased incidences of associated complications have made these fractures particularly problem- atic. Accounting for approximately 5% to 11% of all tibial shaft injuries, 1 they occur as a result of a variety of mechanisms, each of which gener- ates a distinctive injury pattern, with individual treatment requirements. The proximal tibia is highly sus- ceptible to both open and closed soft-tissue damage, with its anteromedial surface being at highest risk. 2 Its posterior cortex is intimately associated with the posterior tibial vessels; as a result, there is a high incidence of arterial injury associated with displaced fractures. As most of the muscle mass is con- centrated in the proximal region, higher rates of compartment syndrome have also been recorded. 3 Proximal tibia fractures pose several treatment challenges. Because the proximal fragment is short, Dr. Bono is Chief Resident, Department of Orthopaedics, New Jersey Medical School, Newark. Dr. Levine is Attending Surgeon, Union Memorial Hospital, Baltimore, Md. Dr. Rao is Clinical Professor of Orthopaedics, New Jersey Medical School. Dr. Behrens is Pro- fessor and Chairman, Department of Ortho- paedics, New Jersey Medical School. Reprint requests: Dr. Bono, Department of Orthopaedics, New Jersey Medical School, MSB, Room G-574, Newark, NJ 07107. Copyright 2001 by the American Academy of Orthopaedic Surgeons. Abstract Nonarticular proximal-third fractures account for 5% to 11% of tibial shaft injuries and occur as a result of a variety of mechanisms. Treatment is more challenging than for more distal fractures, and the rates of compartment syndrome and arterial injury are higher, especially for displaced fractures. Closed management often leads to varus malunion, especially when the fibula is intact. Closed treatment should therefore be reserved for nondisplaced or minimally displaced fractures with little soft-tissue injury. Plating of the proximal tibia has become a less popular alternative because of the high incidence of infection and fixation failure. However, judicious use of lateral plates as an adjunct to medial external fixation in comminuted fractures can be effective. External fixation remains the most versatile method. It is indicated for fractures with short proximal fragments and in cases of extensive soft-tissue injury that would preclude use of other surgical techniques. Temporary joint- spanning external fixation has a role in the initial management of certain fracture patterns, particularly when accompanied by severe soft-tissue injury. Although intramedullary nailing can lead to valgus malunion in a sizable per- centage of patients with this injury, it can be useful for stabilizing fractures with proximal fragments longer than 5 to 6 cm. Placing the entry portal more proximal and lateral, locking in extension, and using specific techniques, such as blocking screws, can improve alignment after nailing. Use of an algorithm that takes into account the severity of soft-tissue injury, the length of the fracture fragment, and the degree of fracture stability allows effective decision making among current treatment techniques. J Am Acad Orthop Surg 2001;9:176-186 Nonarticular Proximal Tibia Fractures: Treatment Options and Decision Making Christopher M. Bono, MD, Richard G. Levine, MD, Juluru P. Rao, MD, and Fred F. Behrens, MD closed reduction and immobilization affords minimal control. This is reflected by the disproportionately high rate of varus malunion with closed treatment. 4 Although open reduction and plate fixation is tech- nically feasible, serious soft-tissue complications can follow extensive exposure. External fixation remains a versatile option for fixation of both open and closed fractures. However, pin-track infection and malunion are frequent complications. 5 Intramedullary nailing is used for stabilization of proximal- third fractures, but has resulted in high malunion rates. 1,6,7 To address these problems, various recommendations have been offered to improve both operative and nonoperative management. 4,8-14 Although each of the available treatment options has proved useful in selected circumstances, none Christopher M. Bono, MD, et al Vol 9, No 3, May/June 2001 177 is universally effective. Proper utilization of an individual technique requires recognition of its role in the continuum of treatment alternatives. Understanding the pertinent anatomy, classification systems, diagnostic modalities, and results of treatment with each modality should increase the appreciation of the difficulty of treating a given fracture and help to avoid the complications and pitfalls of the various treatment methods. Anatomy The proximal tibia is intimately re- lated to the popliteal artery, which lies almost directly on its posterior cortex. It can be directly lacerated by superoposterior displacement of a distal fracture fragment or avulsed during hyperextension injuries. This close relationship may contribute to the high compartment pressures recorded with proximal fractures. 3 The tibial nerve, which courses along the posterior aspect of the knee, is also at risk with posterior displacement of the proximal fragment. The common peroneal nerve traverses from posterior to anterior along the subcutaneous surface of the fibular neck. It may be damaged as a result of direct impact, prolonged compression in a cast, or pen- etration by an external fixation wire. The proximal tibia has muscular compartments covering its lateral and posterior surfaces, but is subcutaneous along its anteromedial aspect. The patellar tendon, which inserts on the tibial tubercle along the anterolateral cortex, can contribute to anterior angulation of the proximal fragment. The thin cortices of the proximal metaphyseal region condense as the bone narrows distally to form a thick diaphyseal cortical tube. The intramedullary zone of the proximal aspect is wide and ill defined, but narrows distally to form a distinct canal. Classification Commonly used classification and grading methods for both the fracture and the soft-tissue injury can be helpful in describing injuries and in recognizing particularly severe types. However, their predictive values are limited, 15 and their interobserver reliability is poor. 16 Al- though there is no system that is specific to nonarticular proximal tibia fractures, the systems generally used for characterizing soft-tissue injury can be applied appropriately. The Tscherne system has been employed for classifying soft-tissue injuries that occur with closed fractures. This system grades injuries from 0 (minor contusions) to III (severe closed degloving, potentially limb-threatening), and has been widely used to characterize closed soft-tissue injury in multiple studies. Fractures in the proximal tibia have proved more severe than middle- third and distal-third injuries and frequently are associated with high- grade soft-tissue lesions. 17 The Gustilo-Anderson classification is the system most commonly used for open fracture grading. Al- though limited by low interobserver reliability, it is still a useful clinical tool. 16 There are five injury-severity grades, with the higher grades being associated with increased rates of infection, amputation, and nonunion. Segmental tibial fractures, even those with an apparently small soft-tissue wound, are classified as high-grade (IIIA) injuries because there is severe underlying soft-tissue disruption. This is of particular importance as proximal tibia injuries with segmental fracture patterns and little appar- ent soft-tissue loss are in fact high- grade injuries. The AO classification is currently the most comprehensive system for describing tibial fracture patterns (Fig. 1). This system considers non- Type A2.1 (lateral oblique) Type A2.1 (medial oblique) Type A2.2 (anterior oblique) Type A3.1 (intact wedge) Type A3.2 (fragmented wedge) Type A3.3 (complex comminution) Type A2.3 (transverse) Figure 1 The AO classification is currently the most comprehensive system for describing tibial fracture patterns. An advantage is that it distinguishes between simple (type A2) and comminuted (type A3) fractures in the proximal extra-articular segment. Nonarticular Proximal Tibia Fractures Journal of the American Academy of Orthopaedic Surgeons 178 articular proximal tibia fractures separately from tibial shaft and plateau fractures. Furthermore, it distinguishes between simple (type A2) and comminuted (type A3) fractures of the proximal extra-articular tibia. Comminuted fractures are generally more unstable. Other factors, including initial displacement, fracture pattern, and severity of soft-tissue damage, must also be considered to develop an accurate assessment of the fracture character; however, those characteristics are not included in the AO classification. 18,19 Finally, the reproducibility of the classification of individual injuries is suspect, as intraobserver and interobserver reliability have not been validated. Evaluation and Diagnosis After the initial trauma evaluation addressing life-threatening injuries, the orthopaedic evaluation begins with assessment of soft-tissue integrity and the neurovascular status of the extremity. This is followed by a systematic survey of all associated injuries. Particular attention must be paid to indicators of substantial soft-tissue injury, such as swelling, lacerations, abrasions, and areas of contusion. The mechanism of injury of proximal tibia fractures is often impact to a pedestrian by a motor vehicle. The extent of soft-tissue damage associated with a tibial fracture caused by this mechanism is often grossly underestimated. 2 Any small puncture wound through the dermis must be presumed to be due to an open fracture. Compartment pressures are higher in proximal-third fractures than in middle- and distal-third fractures. 3 Initial pressure measure- ments should be performed in all cases in which a reliable physical examination is not possible (e.g., in unconscious, sedated, intoxicated, or head-injured patients). Serial or continuous measurement may be warranted if elevated pressures are clinically suspected but not above the threshold for release (i.e., ≤30 mm Hg) on initial evaluation (e.g., tense compartments). In the alert patient, excessive pain, pain with passive extension or flexion of the toes, or neurovascular compromise warrants compartment pressure measurement. Only the early recognition and treatment of tibial compartment syndrome will avoid muscle necrosis, irreversible nerve damage, and the resultant functional loss. Sets of orthogonal radiographs centered on the tibia and knee are the basis for fracture characteriza- tion. The degree of comminution, amount of initial displacement, and fracture planes are noted, as well as the distance from the fracture to the tibial plateau and the tubercle. Fracture lines must be visualized in their entirety. In cases of hemarthrosis with radiographically questionable articular involvement, a sterile knee aspi- rate can be obtained to assess the joint. The presence of intra-articular fat suggests intra-articular fracture. If articular extension is suspected, further imaging must be pursued. Plateau views (with the tube angled slightly caudad) may reveal hidden fractures of the plateau or tibial spine. A computed tomographic study with reconstructions best depicts intra-articular and periarticular fracture patterns, although they are of little value in analyzing nonarticular fracture patterns. Soft-Tissue Management High-energy injuries typically in- volve severe soft-tissue damage. Most severe closed injuries merit observation before fixation. The assessment of the severity of the soft- tissue injury is one of the major factors in determining the optimal definitive management of a given fracture. Fracture blisters and abrasions should be covered with non- adherent dressings, and splints should be used to provide temporary stabilization. Limb elevation and compressive dressings can di- minish swelling and decrease pain. Healing of blood blisters and the return of skin wrinkling after massive swelling are good indicators of resolution of soft-tissue trauma. Open fractures require immediate irrigation and debridement of devi- talized tissue. With massive skin and muscle damage, early secondary coverage procedures are frequently necessary to effect wound closure. Gastrocnemius rotational flaps are useful for proximal tibia injuries, although large wounds or extensive damage may necessitate alternative flap options (i.e., soleus and free flaps). Closed Treatment Closed treatment of displaced fractures involves traction and manipu- lation of the extremity to restore an acceptable relationship between the proximal and distal fragments by correcting translation or angulation. Closed management with either casting or functional bracing is inef- fective in maintaining restored length after reduction. Those injuries that tend to shorten are, therefore, best treated by other methods. Technique For three-point molding to maintain a reduction, the fracture region must have an intact periosteal sleeve, which must be placed under tension. Unfortunately, the short proximal fragment is difficult to manipulate and control with these methods. When casting is indicated, most authors agree that a well-molded long leg cast is most effective for the first 2 to 3 weeks. 4 By including the knee in approximately 10 to 20 degrees of flexion, rotational control in Christopher M. Bono, MD, et al Vol 9, No 3, May/June 2001 179 the cast is facilitated, although some authors recommend less flexion to avoid anterior angulation of the fracture. 4 All bony prominences require careful padding, with special attention to the anterior spike of the proximal fragment. After approximately 3 weeks, the long leg cast can be replaced with a hinged fracture brace constructed of either molded plastic or plaster. 4 The thigh component should extend as far proximally as possible, generally just distal to the medial peri- neal crease. In injuries at the junction of the proximal and middle thirds, a longer proximal fragment may be controlled in a patellar tendon– bearing cast or brace. Generally, patients can progress to weight bearing as tolerated until callus is visible radiographically, at which time full weight bearing can be initiated. Clinical Results There are few studies on closed treatment of extra-articular proximal tibia fractures. Sarmiento et al 4 documented treatment of 68 patients with nonarticular proximal tibia fractures immobilized in a long leg cast for an average of 3 weeks, followed by conversion to a hinged molded-plastic fracture brace. Ac- ceptable alignment was maintained in 84% of 45 cases of combined fractures of the tibia and fibula. In cases in which the fibula was intact, 61% of patients had varus angulation of more than 5 degrees at follow-up. The fibula acts as a lateral buttress, with weight bearing leading to varus deformity. 4 Fibular osteotomy can minimize this complication, but it must be emphasized to the patient that functional alignment, rather than anatomic reduction, is the treatment goal. The main advantage of closed treatment is the avoidance of surgical risks, including postoperative infection, tissue compromise, and iatrogenic neurovascular injury. Successful closed management of a proximal tibia fracture requires an experienced physician and a com- pliant patient. Serial radiographs and multiple cast changes necessitate frequent clinic visits. Early knee motion in either a patellar tendon– bearing cast or a hinged brace can minimize knee stiffness, although long-term loss of range of motion has not been observed in most clinical series. 4 Indications Minimally or nondisplaced fractures of the proximal tibia and fibula without major soft-tissue or neurovascular injury are considered stable and can be successfully treated by closed methods even if the fibula is intact. Closed management of unstable fractures is possible if a reduction can be obtained and maintained; however, close observation is necessary to detect the develop- ment of malalignment. Closed treatment of an unstable fracture with an intact fibula is not recommended, as the rate of varus malunion is high. Although some authors recommend fibular osteotomy to relieve this deforming force, these unstable injuries are best treated by operative fixation of the tibia. Cast management is unsuitable for patients with significant closed or open soft-tissue injuries, as these are usually unstable and the soft tissues require frequent monitoring. Plating Open plating entails considerable surgical exposure to directly visual- ize and anatomically reduce the fracture. This technique has led to substantial soft-tissue complication rates in some diaphyseal and proximal intra-articular fractures and is a recognized risk with high-energy metaphyseal injuries. 12,13,20 Although these complications have not been reported specifically for plate fixation of nonarticular proximal metaphyseal fractures, the concepts of limiting soft-tissue dissection and decreasing the length and size of plate constructs are both applicable and prudent. Technique Unilateral plate osteosynthesis of simple displaced extra-articular metaphyseal fractures can be achieved with either a medial or a lateral plate. A plate is effective as an anti- glide device on the side of the distal spike of an oblique fracture. Better soft-tissue coverage is thought to make lateral plating safer so that laterally comminuted fractures can be stabilized in this manner. With medial comminution, greater damage of the thin soft-tissue envelope generally precludes immediate open medial plating. These fractures are better stabilized by other methods. Fragmentation of both cortices requires medial and lateral buttress- ing. In these situations, success has been documented with composite fixation, in which a simple external- fixator construct is used to maintain medial length while a lateral metaphyseal plate is applied through a limited anterolateral incision. 13,21 Clinical Results Bolhofner 13 examined the outcome of composite fixation in 41 patients with extra-articular proximal tibia fractures with varying degrees of open and closed soft-tissue injury. In all cases, a medial external fixator was applied after closed reduction. After the fracture had been stabilized with single proximal and distal Schanz pins, the metaphysis was sur- gically approached through an anterolateral incision. Final reduction and fixation were achieved with a contoured 4.5-mm dynamic compression plate. For additional medial stability, a third fixator pin was added in the distal fragment when necessary (Fig. 2). External fixators were removed after an average of 8.4 weeks. Pin-track infections occurred Nonarticular Proximal Tibia Fractures Journal of the American Academy of Orthopaedic Surgeons 180 in 12% of cases, and surgical debridement for deep wound infection was required in 5% of cases. Only one malunion (6 degrees of varus angulation) was reported. No instance of hardware failure was observed. In a series of 18 complex proximal tibia fractures, Gerber and Ganz 21 also used lateral plating with medial external fixation. One case of deep wound infection and one malunion were reported. There were no pin-track infections that required surgical intervention. Ries and Meinhard 14 used a similar construct to treat 8 intra-articular and metaphyseal injuries. However, they applied the lateral plate first, followed by medial external fixation. The advantages of plating include direct visualization and reduction of the fracture. Higher infection rates, hardware prominence, and stress risers after plate and screw removal are potential disadvantages. Con- struct failure, particularly in osteo- penic bone, is an important theoreti- cal limitation. Lateral plating with medial comminution can lead to varus collapse if additional stability is not provided. Indications Plating is useful for simple unstable (displaced) transverse or oblique fractures in the proximal metaphysis. In closed fractures with minimal soft-tissue compromise, plates can be strategically placed to control angulation of oblique fractures. For comminuted patterns, the best results with these implants have been reported with lateral plating and medial external fixation. Combined medial-lateral open plating should be avoided for high-energy comminuted fractures, especially in situations with severe closed or open soft-tissue lesions. For plating techniques to be safely performed, the condition of the soft-tissue sleeve is of foremost importance. External Fixation Technique External fixation allows satisfactory stabilization of most extra- articular proximal tibia fractures. Pins should be placed only through intact skin and soft tissue, and strict adherence to recommended corri- dors is advocated to avoid neurovascular damage. Behrens and Searls 22 delineated a 220-degree “safe arc” through which external fixator wires or pins may be inserted into the proximal metaphysis. This arc extends from the proximal tibiofibular joint anteriorly across the front of the tibia to the posterome- dial cortex. Placement of pins outside this safe corridor risks injury to neurovascular structures. Fractures are reduced with a combination of traction and manip- ulation and stabilized with percuta- neously inserted pins or wires connected to rings and/or longitudinal struts. The general principles of external fixation, including maximal pin spread, use of large-diameter pins, and minimization of strut-to- bone distance, should be observed to maximize construct stability. Bi- planar and multiplanar pin fixators are very useful for proximal tibia fractures, as stable fixation of short proximal fragments often necessi- tates placement of at least two pins at the same transverse level. These can be connected to two or more half-pins in the distal fragment with two or more longitudinal rods. 22 For example, a delta-type construct, with medial and lateral Schanz pins in the proximal fragment, is a commonly used construct. If there is sufficient length for placement of two longitudinal pins in the proximal fragment, some fractures are amenable to treatment in a simple monolateral frame. Another option is application of a hybrid external fixator involving insertion of at least three thin crossing wires attached to a proximal five-eighths ring. 20,23 If only two crossing wires can be safely placed, the addition of a single half-pin can increase fixation to the proximal fragment. This is subsequently connected to two or more distal shaft pins by two or more longitudinal struts. Some surgeons prefer to use tensioned olive wires in the proximal fragment 23 (Fig. 3), which theo- retically limit medial-lateral translation better than nonbeaded implants; however, this benefit has not been demonstrated biomechanically. When considering proximal wire placement, it is important to note that the synovial cavity of the knee extends as far as 14 mm below the joint line 22,24,25 and often includes the proximal tibiofibular joint. 26 Placement of external fixation wires through this region of redundant synovium can allow bacterial seed- Figure 2 A, Additional screws are placed in the distal portion of the plate, and the push-pull screw is then removed. B, If additional stability is required because of the fracture pattern, the fibular fracture may be repaired with a 3.5-mm dynamic compression plate. Medial stability may be obtained by placing an additional medial Schanz screw. (Adapted with permission from Bolhofner BR: Indirect reduction and composite fixation of extraarticular proximal tibial fractures. Clin Orthop 1995;315:75-83.) A B Christopher M. Bono, MD, et al Vol 9, No 3, May/June 2001 181 ing of the knee joint, with subse- quent pyarthrosis. 5 It is, therefore, recommended that all external fixation wires be placed at least 15 mm distal to the plateau surface. 24,25 Some surgeons routinely insert wires through the fibular head in an attempt to improve wire offset. In the anterior half of the joint, pin or wire placement may be possible without risk of synovial perforation, 24 although staying anterior to the proximal fibula will generally avoid perforation of capsular re- flections. Clinical Results The availability of clinical data concerning extra-articular proximal tibia fractures treated by external fixation alone is limited. Zecher et al 23 reported on 5 extra-articular metaphyseal injuries in a series of 21 high-energy fractures; treatment with the Monticelli-Spinelli hybrid fixator yielded satisfactory results. Weiner et al 20 reported generally satisfactory results with use of a combination of external and internal fixation to treat 50 proximal injuries, 5 of which were high-energy nonarticular proximal tibia fractures. There is as yet no published series of nonarticular proximal tibial fractures treated by external fixation alone. The main advantage of external fixation is that reduction and stabilization of the fracture fragments is possible with minimal additional insult to the soft-tissue sleeve. If properly constructed, these devices are strong enough to provide stable fixation for most fracture patterns in the proximal tibia. External fixation enables early range-of-motion exercises and secondary adjustment of initial or secondary malalignment. 20 Weight bearing is possible with stable reductions and very stable frame constructs. External fixation is limited by the need for close and prolonged super- vision with repeated office visits to assess and ensure acceptable alignment. 27 Pin-track infections are common and require intensive local care and occasionally systemic anti- biotics. Secondary knee pyarthrosis, uncommon with plating or nailing, has been observed in periarticular fractures treated with external fixation and may be attributed to placement of wires through the synovial reflection of the knee below the tibial articular surface. 5,25 However, most reported cases have involved articular injuries, rather than proximal nonarticular fractures, which afford more room for pin placement. Severe open or closed injury patterns sometimes preclude immediate definitive fixation of the fracture. In these situations, a spanning external fixator can be placed to provide temporary stabilization without causing further damage to the soft- tissue sleeve of the proximal portion of the leg. Two different techniques have been described. Cole et al 28 recommended a construct consisting of three laterally placed distal-femoral- shaft pins connected to a transos- seous calcaneal pin by means of two long rods, effectively providing portable traction to the fracture site. In their series of periarticular injuries, Anglen and Aleto 29 used two anterior femoral and two anteromedial distal tibial pins spanned by double-stacked rods to maintain length and alignment while soft tissues stabilized. Other frame con- Figure 3 A, Preoperative radiographs of a lateral oblique metaphyseal fracture with some comminution. Note the apex anterior angulation and posterior translation on the lateral view and the marked medial translation on the anteroposterior view. The proximal fragment is relatively short. B, Multiplanar tensioned olive wires effectively stabilize the proximal fragment in a hybrid external-fixator construct. Excellent sagittal alignment was achieved, as well as correction of coronal translation. A B Nonarticular Proximal Tibia Fractures Journal of the American Academy of Orthopaedic Surgeons 182 structs are possible, all of which have the same goal of keeping the pins outside the zone of injury and definitive fixation. Indications External fixators can stabilize most fractures of the proximal tibia and are particularly useful for fractures that are complicated by extensive soft-tissue compromise and for patients who have sustained poly- trauma. Circumferential skin damage at the level of the proximal tibia may preclude placement of wires or pins. In this situation, immediate spanning external fixation is indicated for initial management. Intramedullary Nailing Intramedullary nailing has recently become more widely used for nonarticular proximal tibia fractures, although high rates of malunion have been reported. Eccentric starting portals within the wide intramedullary canal of the proximal tibia can lead to malalignment as the nail passes into the more constrained canal of the distal fragment. Careful planning, meticulous attention to technical detail, and the use of recently described techniques are helpful in preventing these deformi- ties (Fig. 4). Clinical Results Many reports of intramedullary nailing of tibial shaft fractures have been documented, but few deal specifically with proximal tibia injuries. 1,6 In a radiographic analysis of immediately postoperative alignment in 145 tibial fractures, Freedman and Johnson 6 reported a 58% rate of malunion in proximal- third injuries, compared with 7% and 8% rates of malalignment in middle-third and distal-third fractures, respectively. Four cases of valgus deformity and five cases of anterior angulation were reported. The propensity for valgus deformity was attributed to the average medial entrance angle of 9.5 degrees, which was potentiated by a medial starting portal. The investigators recommended a central or lateral portal to avoid angulation. The locking con- figuration used with the proximal injuries was not specified; however, many nails used in the series were not locked or were locked dynami- cally. In a smaller series in which dy- namically locked nails were used, Templeman et al 7 documented loss of alignment in 20% of proximal-third fractures, with oblique fractures being among the least stable. Nei- ther group of investigators reported proximal fracture-fragment length, which is an important technical and biomechanical consideration. 11 Lang et al 1 treated 32 nonarticular proximal-third fractures with statically locked intramedullary nails. At least 5 degrees of valgus angulation was noted in 18 fractures (56%), and 9 fractures (22%) had 10 degrees or more of apex anterior deformity. Loss of fixation was reported in 8 fractures, which the authors attributed to proximal locking with only one screw in 50% of cases. A single screw does not prevent rotation of the proximal fragment in the sagittal plane. A posterior entrance angle and a nail bend distal to the fracture site contributed to sagittal malalignment, and a medial starting portal accentuated by a medial parapatellar approach contributed to coronal malalignment. As in previous studies, proximal fragment length was not recorded. The authors illustrated the use of supplemental unicortical plate fixation in conjunction with nailing to improve fracture alignment. The direction and location of proximal locking may make a difference. In a biomechanical study, Henley et al 11 compared the axial, torsional, and varus-valgus stiffness of different proximal locking-screw constructs in models of both a simple transverse fracture and a comminuted fracture of the shaft of the proximal tibia. In the comminuted bone, two coronal screws were stiffer than two oblique (90-degree) screws under axial tension, although this was ex- plained by insertion of the oblique screws more proximally in the softer metaphyseal bone. Valgus-varus stiffness was greater with oblique constructs in both the simple and the comminuted model, with statistically significant differences observed in the former. Stability against flexion and extension forces was not tested. The authors concluded that more proximal locking enables fixation of a greater number of fractures with better control of coronal angulation, but that axial stability may be compromised. The true intramedullary canal begins about 4 cm distal to the tibial tubercle. In the uppermost portion of the proximal tibia, the intramedullary central axis is more often lateral rather than medial to the center A B Figure 4 Postoperative anteroposterior (A) and lateral (B) radiographs after locked nailing of a proximal tibia fracture illus- trate angulatory and translational deformi- ties in both the coronal and the sagittal plane. Christopher M. Bono, MD, et al Vol 9, No 3, May/June 2001 183 of the tibial plateau. 30,31 It has been suggested that lateral starting points may allow better direction of nails into the canal. In addition to allow- ing better anatomic alignment with the canal, a lateral portal has been demonstrated to lower anterior deforming forces within the proximal tibia in cadaveric biomechanical studies. 31 Because a posterior entrance angle is recognized as a cause of anterior angulation, alternative starting portals have been suggested. The standard techniques utilize an entrance through the oblique facet of the tibial metaphysis 2 cm above the tubercle. Tornetta 32 described a more proximal and posterior portal, just anterior to the insertion of the anterior cruciate ligament. Similarly, Buehler et al 10 described a more proximal and lateral entry point in line with the lateral intercondylar eminence. In cadaveric biomechanical studies, similar portals have demonstrated lower angular deforming forces with nail insertion than have been found with more distal and medial sites. 33 Alignment adjustments are difficult after nail insertion. Minor adjustments of valgus or varus malalignment can be achieved by rotating the nail externally or internally, respectively, to use the nail bend to reduce the malalignment at the expense of translating the proximal fragment. If this technique is used, the surgeon must be aware that the locking holes are no longer in the standard position, and, as a result, insertion of the cross-locking screws may endanger neurovascular structures. With resistant angulation, coronal blocking screws can be implanted before nail insertion to effectively reduce the posterior intramedullary space. 9 This forces the nail toward the anterior cortex of the proximal fragment. 28,32 Similarly, sagittal blocking screws can be used to aid coronal alignment. If malalignment develops during nail insertion, ex- traction, placement of blocking screws, and nail reinsertion may improve alignment. Extension forces placed on the proximal fragment with knee hy- perflexion during nailing are also believed to contribute to anterior angulation. 8,10 To minimize this, Tornetta and Collins 8 employed a semiextended approach for tibial nailing. In 25 fractures, they intro- duced nonreamed nails through a medial parapatellar approach. With the patella retracted, the portal was accessible, and the nail was easily inserted while the knee was held in approximately 15 degrees of flexion, reducing the pull of the patellar tendon. After passage across the fracture site, the nail is locked in relative extension, which may be facilitated by newer L-shaped proximal jig de- signs. Locked intramedullary nail fixation of proximal tibia fractures has the advantage of a closed reduction, which maintains the integrity of the perifracture soft-tissue sleeve. Locked intramedullary nailing has made it possible to stabilize proximal tibia fractures with fragments long enough to accept two proximal locking bolts (Fig. 5). The device is completely internal and thus is acceptable to patients and can facilitate early weight bearing by those with unstable injuries. Utilization of intramedullary nailing is limited by the fact that it is applicable only to fractures with sufficiently long proximal fragments, and even in that setting it is techni- cally demanding. As locking-screw location and orientation vary among implant types, careful preoperative measurement of fragment length on both anteroposterior and lateral views is crucial. In addition, fragment length should be considered in regard to the nail bend, which Figure 5 A, Initial radiograph of a proximal tibia fracture. B, The proximal fragment was long enough (7 cm) to accept two proximal locking nails. C, An oblique locking screw was added to enhance coronal stability. The nail bend was located at the fracture site in this case; however, it is preferable for the nail bend to be above the fracture to prevent apex anterior angulation of the proximal fragment. A B C Nonarticular Proximal Tibia Fractures Journal of the American Academy of Orthopaedic Surgeons 184 should be kept proximal to the fracture site to prevent posterior translation. Gross contamination or severe soft-tissue injury should not be pres- ent at the nail-entry site. If these cri- teria cannot be satisfied, alternative methods of stabilization, such as external fixation, should be considered. Indications Fractures with proximal fragments sufficiently long to accept two locking screws and with minimal soft-tissue injury around the knee can be successfully nailed. In large part because of the insuffi- cient clinical data correlating fragment size with outcome, the exact fragment length remains arbitrary and subject to surgeon experience; 5 to 6 cm is probably a reasonable estimation. More proximal injuries at or above the level of the tibial tubercle are very difficult to control with a nail and are best treated with another method. Decision Making In the management of proximal tibia fractures, a neglected or mis- judged soft-tissue injury can lead to devastating complications, including soft-tissue slough and postoperative infection, which may necessitate amputation. The surgeon must, therefore, consider fractures with a seriously compromised soft-tissue sleeve as different from those with less soft-tissue trauma. The severity of the soft-tissue injury is the first discriminator in the proposed algorithm (Fig. 6). Stable, nondisplaced, and minimally displaced fractures with minimal soft-tissue injury can be treated in a closed manner. If the reduction is lost or soft-tissue compromise develops, surgical stabilization is recommended. External fixation is the most reasonable alternative for unstable fracture patterns with short proximal fragments, although Proximal tibia fracture Minimal soft-tissue injury Severe soft-tissue injury Stable fracture Unstable fracture Short proximal fragment Emergent stabilization Short proximal fragment Long proximal fragment Short proximal fragment Nonemergent stabilization Long proximal fragment Long leg cast Loss of reduction External fixation (preferred) or plate fixation Spanning external fixator Soft-tissue healed, bone covered Swelling decreased, blisters resolve Open fracture, compartment syndrome, vascular repair Intramedullary nailing (preferred) or external fixation or plate fixation External fixation or unilateral plate fixation or composite fixation If nail portal intact, external fixation or immediate intramedullary nailing Bulky dressing, splint, and observation or spanning external fixator (for very unstable fractures) Closed fracture, no limb-threatening condition Figure 6 Treatment algorithm for proximal tibia fractures with minimal or severe soft-tissue injury. Christopher M. Bono, MD, et al Vol 9, No 3, May/June 2001 185 some surgeons prefer plate fixation. A lateral buttress plate can be used to stabilize lateral comminution and can be supplemented with a medially placed fixator. Intramed- ullary nailing is a good choice for unstable injuries with minimal soft- tissue injury and proximal fragments longer than 5 or 6 cm. For surgeons inexperienced or uncom- fortable with nailing, external fixation and plate fixation remain viable alternatives. In proximal tibia fractures complicated by severe soft-tissue injuries, the primary focus is on the soft-tissue lesion. In some cases, definitive fixation is delayed until the soft tissues have stabilized. Closed lesions with short proximal fragments warrant prolonged observation (up to 2 weeks) while being temporarily stabilized in a soft dressing and splint. If there is significant fracture displacement and instability, a joint-spanning fixator may be used. Disappearance of blood blisters, return of skin wrinkling, and diminution of swelling are indicators of resolving soft- tissue trauma. With short proximal fragments, definitive fixation can be achieved with an external fixator, plate osteosynthesis, or both. With long fragments with more distal closed soft-tissue lesions, primary nailing can be attempted if the nail- entry site is out of the zone of injury, although external fixation is preferred by some surgeons. All open wounds require prompt irrigation, debridement, and fracture stabilization. Fractures with severe open wounds and small proximal fragments are best stabilized initially with a spanning external fixator across the knee. Delayed conversion to a fixator applied only to the tibia is the most widely recommended choice for definitive stabilization, although with stable soft-tissue closure, plate fixation remains an alternative. An external fixator supplemented with a lateral plate is useful for comminuted patterns. If the proximal fragment is large and the open wound is not contaminated, initial immobilization can be effected with an intramedullary nail if the entry site is out of the zone of injury. Alternatively, if the wound is contaminated or if it is the surgeon’s pref- erence, large proximal fragments may be treated with external fixation. Summary Although there is a wide variety of injury patterns and treatment options, most fractures involving the proximal third of the tibia can be managed successfully by assessing in sequence the severity of the soft- tissue injury, the length of the bone fragment, and the stability of the fracture pattern. Of the available treatment methods, external fixation can be used for any of the described injury patterns. Locked intramedullary nails are most useful and have some advantages for proximal tibia fractures with long proximal fragments and adequate soft-tissue coverage. However, attention to several important factors is necessary to prevent malalignment. Plates are still used by some surgeons and have particular utility when there is an oblique fracture line. With fracture comminution, lateral plating should be augmented by medial external fixation. In cases of severe open or closed soft-tissue injury, plates should be used only with extreme caution or after the soft-tissue injury has completely stabilized. References 1. Lang GJ, Cohen BE, Bosse MJ, Kellam JF: Proximal third tibial shaft fractures: Should they be nailed? Clin Orthop 1995;315:64-74. 2. Burgess AR, Poka A, Brumback RJ, Flagle CL, Loeb PE, Ebraheim NA: Pedestrian tibial injuries. J Trauma 1987;27:596-601. 3. Halpern AA, Nagel DA: Anterior compartment pressures in patients with tibial fractures. J Trauma 1980; 20:786-790. 4. Sarmiento A, Kinman PB, Latta LL: Fractures of the proximal tibia and tibial condyles: A clinical and laboratory comparative study. Clin Orthop 1979; 145:136-145. 5. Hutson JJ Jr, Zych GA: Infections in periarticular fractures of the lower extremity treated with tensioned wire hybrid fixators. J Orthop Trauma 1998; 12:214-218. 6. Freedman EL, Johnson EE: Radio- graphic analysis of tibial fracture malalignment following intramedullary nailing. Clin Orthop 1995;315:25-33. 7. Templeman D, Larson C, Varecka T, Kyle RF: Decision making errors in the use of interlocking tibial nails. Clin Orthop 1997;339:65-70. 8. Tornetta P III, Collins E: Semiex- tended position of intramedullary nailing of the proximal tibia. Clin Orthop 1996;328:185-189. 9. Krettek C, Stephan C, Schandelmaier P, Richter M, Pape HC, Miclau T: The use of Poller screws as blocking screws in stabilising tibial fractures treated with small diameter intramedullary nails. J Bone Joint Surg Br 1999;81:963-968. 10. Buehler KC, Green J, Woll TS, Duwelius PJ: A technique for intramedullary nailing of proximal third tibia fractures. J Orthop Trauma 1997;11:218-223. 11. Henley MB, Meier M, Tencer AF: Influences of some design parameters on the biomechanics of the unreamed tibial intramedullary nail. J Orthop Trauma 1993;7:311-319. 12. Matthews DE, McGuire R, Freeland AE: Anterior unicortical buttress plating in conjunction with an unreamed interlocking intramedullary nail for treatment of very proximal tibial diaphyseal fractures. Orthopedics 1997; 20:647-648. 13. Bolhofner BR: Indirect reduction and composite fixation of extraarticular proximal tibial fractures. Clin Orthop 1995;315:75-83.