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    Open Tibia Fracture with an Old Malunion: What to Do?

    Definitive fixation of a right open diaphyseal tibia fracture was complicated by a prior fracture of the same tibia sustained nearly 50 years earlier. Using 3D-printed models of the tibia and fibula, the author was able to modify a long proximal tibial locking plate to fit the unique shape of the patient’s tibia.

    Author

    Brandon J. Yuan, MD

    Case Presentation

    A 67-year-old, otherwise healthy male presents to the emergency department with a right open diaphyseal tibia fracture sustained in a motorcycle collision.

    This is not the first time the patient fractured the tibia: In 1973, he sustained a slightly more distal right tibia fracture that was initially managed non-operatively. Due to non-union of the fracture, he eventually received posterolateral bone grafting. This resulted in successful union. The patient had no functional deficits, perceptible leg length discrepancy, or rotational deformity related to the prior tibia fracture.

    Initial radiographs of the current right tibia fracture (Figure 1) show that the old distal diaphyseal malunion has resulted in nearly 100% lateral translation in the frontal plane and minimal deformity in the sagittal plane. The acute fracture is a spiral, segmental fracture of the proximal metadiaphysis, with 2 intercalary comminuted segments.

    Figure 1. Initial radiographs show the acute right diaphyseal tibia fracture and the old distal diaphyseal malunion.

    There is also a 5-cm laceration over the anterior aspect of the distal aspect of the fracture, just proximal to the malunion.

    In the emergency department, the patient received intravenous (IV) antibiotics – which should be part of the initial treatment of an open tibia fracture – and a tetanus vaccine booster. He was placed into a long leg splint with plans for operative debridement and stabilization of the fracture.

    Treatment Options

    Treatment of this open tibia fracture is intriguing and includes several viable options. As mentioned, initial treatment should include open operative debridement of the fracture site and stabilization of the tibia. The patient should also be monitored closely for signs and symptoms of compartment syndrome.

    After initial debridement, the choice of stabilization includes:

    Cast immobilization. Sarmiento et al [1] reported good results with cast immobilization and subsequent functional brace stabilization of open tibia fractures following operative debridement. The morphology of this fracture is less than ideal for non-operative treatment: The fracture is rotationally and axially unstable, given its segmental nature, and would be at risk for varus malalignment with the intact fibula. In addition, the compromised soft tissue envelope around an open tibia fracture is often best managed with more rigid skeletal stabilization.

    External fixation of the tibia. This treatment option would have the advantage of easily managing the prior deformity. Disadvantages include the risk of pin site infection, joint stiffness, and likely increased risk of non-union.

    Internal fixation with an intramedullary nail. The distal malunion would need to be corrected via an osteotomy to allow passage of the intramedullary device.

    Internal fixation with a plate. This treatment option would have the advantage of providing rigid internal fixation, and it could be modified to accommodate the existing distal tibial malunion without need for correctional osteotomy. However, plate fixation of open tibia fractures may increase the risk of infection in the event of wound healing difficulties. In addition, the severity of the prior deformity would involve complex manipulation of the plate.

    Initial Operative Treatment

    On the day of the injury, I took the patient to the operating room for debridement of the tibia fracture through the traumatic open anterior wound. This afforded direct access to a long oblique fracture line separating the distal fracture fragment from 1 of the large intercalary fragments. Fluoroscopic images show direct reduction and compression of this long oblique fracture with a clamp (Figure 2).

    I placed a pair of 3.5-mm cortical lag screws across the long oblique fracture line to compress it anatomically (Figure 3). A separate medial intercalary fragment was not reduced, as it would have required extensive dissection over the anteromedial aspect of the tibia, away from the already open wound.

    Figure 2. A clamp was used for direct reduction and compression of a long oblique fracture line separating the distal fracture fragment from 1 of the large intercalary fragments.

    Figure 3. Two 3.5-mm cortical lag screws were placed across the long oblique fracture line to compress it anatomically. A medial intercalary fragment was not reduced.

    Eventually, I had planned for the patient to undergo plate fixation of the tibia, but definitive treatment could not be done at the time of the initial surgery: Plate fixation would require significant planning and manipulation of the plate. Instead, I elected to place a knee spanning external fixator from the distal femur to the distal tibia. This would allow me to defer definitive fixation to another date . In the event that intramedullary fixation was chosen, the lag screws could easily be removed at the time of definitive fixation.

    The patient’s anterior tibial wound was closed primarily.

    3D Modeling of the Fracture

    A CT scan performed following the initial debridement and stabilization showed anatomic reduction of the long oblique fracture line compressed with lag screws, and near anatomic alignment of the other 2 fracture fragments: a comminuted segment along the posterior medial cortex of the tibia and the proximal tibia segment (Figure 4).

    Figure 4. The CT scan shows anatomic reduction of the long oblique fracture line compressed with lag screws, and near anatomic alignment of the other 2 fracture fragments.

    To assist with plate fixation, I requested 3-dimensional (3D) printed models of the tibia and fibula that could be utilized as a provisional model for manipulation of the plate prior to surgery (Figure 5). A long proximal tibial locking plate (DePuy Synthes; West Chester, Pennsylvania) was modified to fit the unique shape of the patient’s tibia, utilizing the model as a guide (Figure 6).

    Figure 5. 3D model of the tibia and fibula, with the existing distal tibial external fixation pin sites and the 3.5mm lag screws shown in blue.

    Figure 6. 3D model of the tibia and fibula showing how the proximal tibia locking plate was modified to fit the patient’s tibia.

    The 3D models of the tibia and fibula with the modified proximal tibial locking plate allowed for complex manipulation of the plate on the day prior to surgery. Without the 3D models, exact contouring of the plate would have required direct exposure of the entire anterior and lateral surface of the patient’s proximal tibia. With the 3D models, the plate could be applied with minimal direct surgical exposure while still allowing precise contouring.

    Definitive Fracture Fixation

    The patient was taken to the operating room for definitive internal fixation 14 days following initial debridement. The external fixator was removed. Intraoperative fluoroscopic images showed the clamp-assisted reduction of the long oblique proximal fracture line through a standard anterolateral exposure of the proximal tibia (Figure 7). The 3.5-mm lag screws were utilized to compress the more proximal fracture line.

    Figure 7. Clamp-assisted reduction of the long oblique proximal fracture line through a standard anterolateral exposure of the proximal tibia.

    The pre-contoured plate, which had been sterilized for use in the surgical case, was then passed submuscularly from the proximal anterolateral exposure down to the distal tibia. A separate anterolateral incision was made at the level of the distal tibia to expose and position the distal end of the plate. The remainder of the central aspect of the tibia was not directly exposed.

    Two 4.5-mm cortical screws were placed through the plate percutaneously for reduction and stabilization of the final intercalary segment along the medial aspect of the tibia. The plate was secured to the distal tibia just above the level of the ankle, as seen in the final fluoroscopic image (Figure 8).

    Figure 8. Fluoroscopic images show reduction and stabilization of the intercalary segment along the medial aspect of the tibial, as well as fixation of the plate to the distal tibia above the level of the ankle.

    Radiographs taken in the immediate postoperative period showed anatomic reduction of the acute tibial fracture with application of the pre-contoured plate (Figure 9).

    Figure 9. Postoperative radiographs following definitive fixation of the tibial fracture.

    The patient was made toe-touch weight-bearing on the operative leg for 6 weeks postoperatively and then transitioned to weight-bearing as tolerated. Knee and ankle range of motion were encouraged immediately.

    Radiographs obtained 6 months following operative fixation showed a healed tibia fracture with minimal callus formation and near disappearance of the fracture lines (Figure 10). The patient had returned to all activities as tolerated.

    Figure 10. Healed tibia fracture with minimal callus formation and near disappearance of the fracture lines at 6 months following definitive fixation.

    Key Points

    • Open fractures require urgent evaluation and administration of antibiotics. The patient’s tetanus status should be updated as appropriate. Initial surgical treatment involves thorough operative debridement of the open fracture and skeletal stabilization to allow for appropriate soft tissue healing.
    • This particular fracture could have been managed a few different ways, including with cast immobilization, external fixation, osteotomy and nail fixation, or plate fixation.
    • This example highlights some of the advantages of the use of 3D printing for preoperative surgical planning.
      • The severity of the patient’s pre-existing tibial malunion would have made intraoperative contouring of the plate to fit the tibia difficult and likely would have required extensive direct surgical exposure of the anterior and lateral surface of the tibia.
      • The use of a 3D-printed model of the tibia preoperatively allowed for contouring of the plate prior to proceeding to the operating room. This not only saved significant time intraoperatively, but it also allowed for minimally invasive application of the plate.

    The use of 3D printing technology is likely to have additional applications for the treatment of acute traumatic injuries and their sequela.

    Author Information

    Brandon J. Yuan, MD, is an Assistant Professor in the Division of Orthopedic Trauma at Mayo Clinic, Rochester, Minnesota.

    Disclosures: Dr. Yuan has no disclosures relevant to this article.

    Reference

    1. Sarmiento A, Gersten LM, Sobol PA, Shankwiler JA, Vangsness CT.Tibial shaft fractures treated with functional braces. Experience with 780 fractures. J Bone Joint Surg Br. 1989 Aug;71(4):602-9. doi: 10.1302/0301-620X.71B4.2768307.