Tibial plateau fractures are the result of strong valgus stresses combined with axial loading. Literature statistics show that 55%~70% of tibial plateau fractures are tibial lateral condyle fractures. At this point, the femoral condyle exerts shear and compressive stress on the underlying tibial plateau, which can result in a split fracture, a collapse fracture, or both. However, there are different opinions in the literature on whether varus stress causes tibial medial condyle fractures, one opinion is that the femoral lateral condyle exerts shear stress on the tibial medial condyle when valgus stress is still the case, and the other opinion is that there is a tibial medial dydyle fracture caused by varus stress.
At present, with the increasing use of MRI examination, it is found that the incidence of ligament injury in patients with tibial plateau fracture is higher than previously thought, and meniscus and soft tissue injury are often combined. Meniscus injuries in tibial plateau fractures account for about 67%. The causes of injury are traffic accidents, car collisions, falls from heights or sports injuries are the most common, and the elderly have osteoporosis, and tibial plateau fractures can occur even if the external force is slight.
Schatzker typing
The Schatzker classification system was used to classify fracture types:
Type I:
Simple split fracture (Figure 1A): a typical wedge-shaped, noncomminuted fracture fragment that is dislocated outward and inferiorly. This type of fracture is common in young patients without osteoporosis. If there is displacement, it can be fixed with 2 cancellous screws of transverse bones.
II. Type:
Cleavage with compression fracture (Fig. 1B): Lateral wedge-shaped bone fragment splits and separates with the joint facing down and compresses into the metaphysis. This type of fracture is common in elderly patients, if the compression exceeds 5~8mm or there is knee instability, it should be incisional reduction, and the "whole" bone graft pad at the metaphyseal end of the high compression platform should be fixed with cancellous bone screws and lateral cortical support plates.
III. Type:
Isolated central compression fracture (Fig. 1C): simple articular surface compression depression plateau with intact lateral cortex. Predisposes to occur in patients with osteoporosis. If compression is severe or joint instability is confirmed, bone grafting should be used to cushion the high-compression articular surface and support plates to immobilize the lateral cortical bone.
IV. Type:
Medial condylar fracture (Fig. 1D): this type of fracture can be a simple medial condyle wedge-split, comminuted, or compression fracture, often involving tibial spines. This type of fracture tends to be angled inwardly and should be reduced by open reduction and immobilized by a subchondral raft to reduce damage to the articular surface, with or without plate fixation.
V-shaped:
Bicompartmental fracture (Figure 1E): cleavage of the tibial plateau on both sides. It is characterized by the fact that the metaphysis and diaphysis still maintain their continuity. Both condyles can be fixed with support plates and cancellous screws to avoid fixation with bulky infalls. Moore, Patzakis, and Harvey performed a retrospective study of 988 patients with tibial plateau fractures, 296 of whom had bicompartmental fractures. Among them, 95 cases underwent open reduction and internal fixation, and only 11 cases were fixed with steel plates on both the medial and lateral sides. Nine of the 11 cases (82%) developed wound dehiscence or infection. In addition, 23% of V-bicompartmental fractures were found to be infected. A small non-slip steel plate is used to fix the tip of the fracture with less soft tissue peeling.
VI. Type:
Plateau fracture with metaphyseal and diaphyseal separation (Fig. 1F): transverse or oblique fracture of the proximal tibia in addition to unicompartmental or bicompartmental and articular surface fractures. Due to the separation of the diaphyseal and metaphysis, this type of fracture is not suitable for traction treatment, and most of them are fixed with support plates and cancellous screws. If both condyles are fractured, bilateral fixation is required. Recently, some scholars have advocated the use of steel needles and wires to fix these complex fractures.
Fig.1 Fracture type A.I, simple split fracture, B.II., split combined collapse fracture, bone grafting in the void of the metaphysis to elevate the bone fragment to reduce, support plate to fix the lateral wedge-shaped bone mass: C.III. type, simple central collapse fracture, no external wedge-shaped bone mass, collapse can be anterior, posterior, or involve the entire plateau. After the bone graft cushion collapses, it is best to add a supporting steel plate to protect it, D.N type, medial condyle wedge splitting, medial condyle mold splitting (type A, as shown in the figure) or crushing collapse (type B, not indicated, more common in elderly patients with osteoporosis) : E, V-type, splitting of the tibial plateau on both sides, pay attention to the continuity of the epiphysis and the backbone, must be fixed bilaterally with support plates, F, V-shaped, the fracture is characterized by the separation of the metaphyseal and the diaphysis, the type of fracture of the condyle is uncertain, all types can occur, and the proximal tibia should be fixed with bilateral support plates
Hohl-Moore typing
Hohl and Moore classified proximal tibial articular surface fractures with dislocation (Figure 2). In addition to ligament injury, this type of fracture is often accompanied by meniscus injury, and is usually irreparable. In addition, it is associated with a higher incidence of vascular nerve injury, which increases from 2% in type I to 50% in type V, with an average of 15%, which is similar to the incidence of vascular nerve injury in typical knee dislocation.
Fig.2 Hohl and Moore classification of proximal tibial fracture-dislocation
Type I coronary fissure fracture:
It accounts for 37% of tibial plateau fracture-dislocations. This type of fracture involves the medial aspect of the tibial plateau, and the lateral view is obvious, and a fracture line can be seen in the oblique coronal cross-section at 45° oblique to the medial plateau. The fracture can extend to the outside, resulting in avulsion fractures of the fibular styloid process, cruciate ligament attachment point, and Gerdy's tuberosity, half of the fractures of this type are stable on stress X-ray observation, although non-surgical treatments such as straightened plaster immobilization or traction under limited range of motion are effective, but we often use closed reduction and percutaneous screw fixation, which can improve reduction and allow the affected limb to move early under the protection of a castular brace, and give a protective weight-bearing exercise that lasts for 8~10 weeks. If open reduction is required, the fracture fragment is reduced in the straight position and fixed with interfragmentary screws and the ligament injury is repaired along the tear of the joint capsule.
Type II-condylar fracture:
This type of fracture-dislocation can involve the medial or lateral tibial plateau, and the fracture line extends below the intercondylar spine to the contralateral interarticular compartment, which is distinguished from type IV fractures (figure 3). Of these, 50% of fractures present with contralateral collateral ligament injury, resulting in fracture or dislocation of the proximal fibula. This type accounts for 25% of all fracture-dislocations, and 12% of them are accompanied by vascular and nerve damage. Stress testing is necessary to determine the presence of potential ligament damage. Stable fractures can be treated with immobilization with a cast-type brace, with close follow-up and delayed weight-bearing. For fractures that are unstable or poorly reduced, interfragmental screw fixation, repair of the injured ligament, immobilization with a tubular brace, and delayed weight-bearing can be performed after closed or open reduction.
Type III-marginal avulsion fractures:
This type of injury accounts for 16% of all fracture-dislocation injuries and almost always occurs on the lateral plateau and manifests as avulsion fractures of the capsular attachment site, Gerdy's tuberosity, or tibial plateau, often with cruciate ligament rupture. Meniscal injuries are rare, but 30% of them are associated with vascular nerve injury, and almost all type III fractures are unstable. Lateral pavement screws are required to fix the labun labrum, repair the avulsed iliotibial band and collateral ligament, and repair the cruciate ligament type IV - marginal compression fracture: this type of injury accounts for 12% of all fracture-dislocation injuries and is almost always unstable. This injury results in avulsion or tearing of the contralateral collateral ligament complex and most (about 75%) of the cruciate ligament, and subluxation of the tibia, resulting in compression of the anterior, posterior, or "middle" labial lip of the femoral condyle. Stability injuries can be immobilized with a cast until the ligaments heal. If surgery is required, the parapatellar bypass is removed, the small bone fragments are removed, the larger bone fragments are raised and fixed, and the cruciate ligament and the contralateral collateral ligament are repaired. The characteristics of ligament injury and its repair determine the mobility of the postoperative joint.
V-type four-part fractures:
It accounts for 10% of all fracture-dislocation injuries and is almost always unstable. Among them, 50% were accompanied by vascular and nerve damage, and more than 1/3 were combined with popliteal artery and peroneal nerve injury. The bilateral collateral ligament complex is torn due to a bicondylar fracture, and the stability provided by the cruciate ligament disappears as the intercondylar bulge has become a separate bone mass. Although a bicompartmental approach has been suggested, some scholars recommend that the steel plate be fixed on the side that is more severely pulverized, and the tension screw on the side that is relatively intact. In view of the widespread exposure required for bicompartmental plate fixation, and infection and wound dehiscence are common, Mast introduced a method of lateral plate fixation and medial temporary external fixator fixation. We use limited open reduction, percutaneous needle-piercing triangular external fixator, or 1lizarov external fixator to immobilize the knee in a neutral position. When dealing with Schatzker V-type bicompartmental fractures, special attention should be paid to the soft tissues until the skin has healed, and the timing of weight-bearing should be determined according to the fixation method. Those who are immobilized with the Ilizarov external fixator can bear weight early if they can tolerate it.
Fig.3 Tibial plateau fracture and dislocation A. Tibial plateau type II fracture dislocation fixed with steel plate and screws, B. Internal fixation with supporting steel plate and screws
Schatzker typing is one of the most widely used classification methods in clinical work. Rao Haijun et al. found that most of the postoperative complications in patients with tibial plateau fractures with different Schatzker classifications were related to insufficient evaluation of the fracture in terms of comminutement, location, direction, etc., so that the improper surgical approach and actual selection increased the incidence of complications such as poor fracture reduction, infection, and skin necrosis, which had no obvious relationship with Schatzker classification, and was consistent with the results of this study. Tibial plateau fracture is generally caused by high-energy injury, patients are mostly combined with tissue damage, and the knee joint is around the blood supply and soft tissue coverage of the weaker area, only the subcutaneous tissue and skin cover the joints and tendons, if the timing of the operation is not appropriate, it may lead to severe swelling of the patient, may lead to ligament and tendon necrosis, skin infection and necrosis.
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