Coronal split fracture of the proximal tibia epiphysis through a partially closed physis: a new fracture pattern

SUMMARY

A comminuted coronal split fracture of the proximal tibial epiphysis is an uncommon injury in children. The authors evaluated and treated two patients who sustained an epiphyseal fracture through a partially closed proximal tibial epiphysis. Plain radiography and computed tomography with three-dimensional reconstruction showed a comminuted coronal split fracture of the proximal tibial epiphysis. Each patient underwent definitive operative fixation of the fracture and was followed at least 1 year after clinical union. A mechanism consisting of three-point bending on the tibial plateau is proposed.

Nonarticular proximal tibia fractures: treatment options and decision making

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 percentage 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.

Missed and associated injuries after subtalar dislocation: the role of CT

Subtalar joint dislocation (STJD) is an uncommon injury, but carries with it a potential for significant functional disability. We hypothesized that a significant number of injuries associated with subtalar joint dislocation may be unrecognized by plain radiographic examination. Therefore, we reviewed the records of all STJDs over a three-year period, identifying nine cases. The majority of injuries occurred in men (78%) with a mean age of 29 years. Overall, the mean age at injury was 32 years. The right lower extremity was most frequently injured (87.5%). Plain films initially diagnosed a STJ dislocation in all patients. A CT scan was performed in all cases. In 100% of patients, CT identified additional injuries missed on initial plain radiographs. In 44% of patient, new information gathered by CT dictated a change in treatment. Based on our findings, we conclude that CT is an invaluable tool to assess for associated injuries in STJ dislocation, and should be performed in all cases of STJ dislocation.

Complications of ankle fractures in diabetic patients

Ankle fracture in patients with DM mandates a stepwise protocol to minimize the potential complications of delayed fracture healing, wound complications, and development of Charcot arthropathy. For nondisplaced ankle fracture, a nonoperative approach with increased duration of immobilization seems successful based on experience of the limited series. A displaced ankle fracture in a patient with DM requires a surgical intervention. The authors advocate tight glucose control in both groups to improve the fracture milieu and to ameliorate the potential complications. Appropriate stable fixation with adequate length of immobilization is crucial for successful fracture resolution.

Percutaneous methods of tibial plateau fixation

Various methods of percutaneous fixation of tibial plateau fractures are available. The optimal method of fixation is dictated by soft tissue injury, fracture characteristics, and functional demands of the patient. Unicondylar fractures are amenable to percutaneous stabilization with screws or plates although some fractures are best approached with open techniques. Hybrid and ring external fixators are most appropriate for patients with bicondylar injuries who have severe soft tissue trauma. Use of intramedullary nails to align ipsilateral shaft fractures adjacent to percutaneously fixed plateau injuries remains controversial but may be indicated for some patients with bicondylar lesions and combined plateau and shaft fractures.

Deformity correction and reconstructive procedures using percutaneous techniques

Corrections of deformities in adults traditionally have been performed with open exposure of the lesions, precise bone cuts, rigid plate fixation, and delayed weightbearing. By obtaining a good preoperative evaluation, and meticulously planning each step of the corrective sequence, good technical results and improved functional capabilities can be attained using percutaneous techniques.

'Floating pelvis'. A combination of bilateral hip dislocation with a lumbar ligamentous disruption

A patient is described with a ligamentous disruption at the L4/L5 level in association with bilateral, traumatic dislocations of the hip. The diagnostic evaluation, acute intervention, and definitive stabilisation are reported. The unstable spine posed a problem in treatment with regard to the timing and technique of the reduction of the hips.

Micromechanical properties of epiphyseal trabecular bone and primary spongiosa around the physis: an in situ nanoindentation study

The elastic modulus and hardness of the mineralized bone around the growth plate was measured to determine its regional micromechanical properties. Multiple nanoindentation tests, >10 sessions, with depths ranging from 100 to 1,000 nm at loading rates of 12.5 and 750 microN/s, were performed on the trabecular bone in the epiphysis, trabecular bone at the junction of the physis and epiphysis, primary spongiosa in the metaphysis, and surrounding cortical bone of the distal femur of 300-gm Sprague-Dawley rats. The indentation load-displacement data obtained in these tests were analyzed to determine the elastic modulus and hardness of the tissues. The nanoindentation results highlighted the regional variations in the material properties of the mineralized tissues around the growth plate. The primary spongiosa had a lower elastic modulus and hardness than both epiphyseal trabecular and cortical bone (p < 0.01). A relatively well-defined thick trabecular band at the physeal-epiphyseal junction had modulus and hardness values comparable to those of cortical bone (p > 0.05). These findings support the hypothesis that the primary spongiosa has micromechanical properties that are significantly lower than the epiphyseal trabecular bone. On this basis, it is speculated that the fracture patterns commonly seen in patients with physeal injuries are influenced by the micromechanical properties of these tissues, as well as by the nature and direction of the applied force.

Programmed removal of chondrocytes during endochondral fracture healing

This investigation tested the hypothesis that the removal of chondrocytes during endochondral fracture healing involves an ordered process of programmed cell death. To accomplish this, unilateral closed fractures were created in the femora of 36 Sprague-Dawley rats. The rats were killed in groups of four on days 1, 3, 7, 14, 21, 28, 42, 49, and 56 after fracture. The femora were embedded in paraffin and tested for expression of specific markers of fragmented DNA with use of a terminal deoxyuridyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) technique. To determine the potential for transdifferentiation of chondrocytes to osteoblasts, calluses were also hybridized to detect expression of osteocalcin mRNA. Cell proliferation was assessed by an immunohistochemical detection method for proliferating cell nuclear antigen. A separate group of four rats was killed on day 28 to represent the later stage of the endochondral ossification, and the calluses were examined for cellular morphology with transmission electron microscopy. The results showed a coordination in both time and space of the activities of cellular proliferation and programmed cell death. Cell proliferation was most active in the earlier phases of fracture healing (days 1 through 14), although TUNEL expression was apparent in hypertrophic chondrocytes on day 14 after fracture and persisted until day 28. In the later stages of fracture healing (days 14 through 28), proliferating cell nuclear antigen was no longer synthesized in hard callus (intramembranous bone) and cell removal was the dominant activity in soft callus chondrocytes. Expression of osteocalcin mRNA was detected in osteoblasts but not in hypertrophic chondrocytes or in any other nonosteoblastic cell type. These findings support the hypothesis that the removal of chondrocytes during endochondral fracture healing is part of an ordered transition of tissue types in which the cellular mechanisms are genetically programmed to involve proliferation, maturation, and apoptotic cell death.

Regional and temporal changes in the acoustic properties of fracture callus in secondary bone healing

Controlled fractures were created in the right femora of 17 male Sprague-Dawley rats. The fractured limbs were harvested at 2, 4, 6, and 8 weeks after fracture, fixed, and embedded in polymethylmethacrylate. Midsagittal sections from each animal were evaluated with a scanning acoustic microscope, a device that generates an acoustic impedance map of the scanned material. The impedance of the fracture callus was measured in six regions on each specimen. These regions were chosen in an effort to distinguish between the impedance of the callus formed through intramembranous or endochondral ossification, and we found that the time course of increasing impedance differed for the fracture callus formed through the two pathways. Additionally, we found a significant difference in the mean impedance of the callus at each time period (p < or = 0.0013 for all comparisons), which resulted in an extremely linear relationship (r2 = 0.999) between mean callus impedance and healing time. This experimental model has become a popular choice for the investigation of fracture healing. As such, an accurate determination of the mechanical properties of the fracture callus is often sought. We propose that the implementation of scanning acoustic microscopy in the study of fracture healing may determine the changes in the material properties more accurately than conventional testing methods.

Bicondylar tibial plateau fractures treated with a hybrid ring external fixator: a preliminary study

Twenty-three knees in 22 patients with Schatzker type VI tibial plateau fractures were treated with a hybrid ring external fixator using tensioned wires proximally and half-pins distally. All but two injuries were secondary to high-energy trauma. Six were open injuries, and eight patients had other major musculoskeletal trauma. Eight patients were treated with limited open reduction and internal fixation before application of the frame. The remainder received percutaneous cannulated screw fixation to stabilize the articular surface without opening the fracture site. Twenty-three fractures were followed to complete healing. Average time to healing was 4.4 months. Arc of motion averaged 107 degrees, and there were four flexion contractures of 5-15 degrees. Complications consisted of three deep wound infections, one deep venous thrombosis (DVT), one malunion, and one pin tract infection. The average knee score and patient function score were 84.7 and 80.5, respectively (Knee Society Clinical Rating System). There were 13 excellent, three good, one fair, and six poor results. The poor results were in patients who either developed deep wound infections or in those who sustained multiple musculoskeletal trauma compromising the patients' function score and ultimately the average score. This method provides good stabilization and allows early range of motion for complex tibial plateau fractures where extensive dissection and internal fixation are contraindicated due to traumatized soft tissue, osteopenia, and fracture comminution.

Open tibial fractures with severe soft-tissue loss. Limb salvage compared with below-the-knee amputation

The long-term outcomes and the quality of life were studied in patients who had had an open fracture of the tibial shaft with severe soft-tissue loss. Limb salvage with a free flap was attempted in twenty-seven patients (sixteen of whom had a successful procedure and were examined personally by us), while eighteen patients were managed concurrently with an early below-the-knee amputation. Soft-tissue coverage was successful in all but one patient in whom limb salvage had been attempted. Ultimately, however, five extremities were amputated, with an infection at the site of a non-union being the most common reason for amputation. The patients who had had limb salvage had more complications (p < 0.001), more operative procedures (p < 0.001), and a longer stay in the hospital (p < 0.05) than the patients who had had an early below-the-knee amputation. The long-term functional results for sixteen patients who had had a successful limb-salvage procedure (average duration of follow-up, thirty-five months) were compared with those for eighteen patients who had had a below-the-knee amputation (average duration of follow-up, forty-four months). The patients who had had a successful limb-salvage procedure took significantly more time to achieve full weight-bearing (p < 0.05), were less willing or able to work (p < 0.01), and had higher hospital charges (p < 0.006) than the patients who had been managed with an early below-the-knee amputation. They also had a significant decrease in motion at the ankle and subtalar joint in the injured leg compared with the contralateral leg (p < 0.001). A quality-of-life evaluation was possible for only thirteen of the patients who had had a successful limb-salvage procedure and for sixteen of the patients who had had a below-the-knee amputation. The two groups were similar in terms of their responses, but significantly more patients who had had limb salvage considered themselves severely disabled (p < 0.05). They also had more problems with the performance of occupational and recreational activities (p < 0.05). This study confirmed the reliability of modern microvascular free tissue techniques for the coverage of large soft-tissue defects associated with tibial fractures. It also showed that complications and difficulties in the restoration of osseous union are common and may be directly related to the less satisfactory functional, occupational, recreational, and quality-of-life outcomes that are seen in many patients who have had limb salvage.(ABSTRACT TRUNCATED AT 400 WORDS)