Application of Intelligent Computer-Assisted Taylor 3D External Fixation in the Treatment of Tibiofibular Fracture: Retrospective Case Study

Introduction

With the development of modern society, severe and complex tibial fractures caused by high-energy injuries such as traffic accidents have gradually increased. At present, the commonly used methods for the treatment of tibial fractures include plate fixation, intramedullary nail fixation, and external fixation. Most of these fractures are open wounds with severe soft tissue injury and wound contamination, and some involve bone defects, which makes internal fixation treatment difficult. Potential complications include postoperative wound infection, chronic osteomyelitis, delayed fracture healing, and fracture nonunion. The incidence of malunion healing is high, often resulting in treatment failure [1]. External fixation technology is a good method for the treatment of such fractures. External fixation can reduce the damage to soft tissue, and reduce the risk of postoperative wound infection, osteomyelitis, delayed fracture healing, and fracture nonunion. While complications occur, fracture fixation can be performed in the early stages after an injury, which provides a better prognosis for soft tissue repair, limb care, and early functional exercise [2]. However, in the past, external fixation stents for the treatment of complicated tibiofibular fractures have had poor stability for fracture fixation. They can only be used as a temporary fixation method. Most of the latter require secondary surgery to replace internal fixation, which makes the treatment period prolonged and significantly increases the cost of fracture treatment. Additionally, the fracture healing time is prolonged.

Based on the Ilizarov circular fixator (ICF), a previous study [3] applied the Stewart platform and Charles theory to the field of orthopedics, and combined these with computer software to invent the Taylor 3D space frame. Taylor 3D external fixation (TSF) is a good complement to the deficiencies of the ICF for multidimensional planar fractures and deformity correction. TSF has the following advantages in the treatment of tibial fractures: TSF is quick and easy to learn; accurate closed reduction of fractures can be achieved with computer software assistance during or after surgery; TSF is a better option for ensuring fixation stability of fractures; and the external fixator can be used as a long-term fixation method. The stent is maintained during the entire process of fracture healing. The needle is fixed during the installation process. It does not cause secondary damage to the local soft tissue. The risk of postoperative infection is low, and the rate of fracture nonunion is low. Fracture surgery can be performed soon after the injury to achieve early functional exercise. Postoperative bone defects can be repaired by adjusting the external frame. There are many reports on the use of TSF in the treatment of limb deformities, although there is little literature on the use of TSF in the treatment of tibial fractures.

To further explore the efficacy and possible complications of this technique in the treatment of severely complex fractures, this study retrospectively analyzed 28 cases of severe tibial fractures treated with TSF. This study will provide a theoretical basis for the clinical application and improvement of this technology. The follow-up data of 42 patients with severe tibiofibular fractures treated with internal fixation were compared with that of the TSF group to further evaluate the efficacy of TSF.

Methods

General Information

The TSF group included 28 patients with severe tibial fractures treated with TSF in our department from May 2015 to June 2018. These cases included 23 males and 5 females, aged 19 to 65 years (mean 38.5 years). These cases included 18 traffic accidents, 6 heavy bruises, 4 high fall injuries, 17 open fractures (according to Gustilo classification: 12 of type II and 5 of type III), and 11 closed fractures (according to Tscherne classification: there were 8 level 2 cases and 3 level 3 cases). According to the fracture line classification, there were 10 cases of transverse shape fracture line, 6 cases of oblique shape, 3 cases of spiral shape, 5 cases of comminuted fracture, and 4 cases of multiple fractures. According to the location of the fracture, there were 7 cases in the proximal one-third of the bone, 5 cases in the middle one-third, 11 cases in the middle and distal junctions, and 5 cases in the distal one-third. Compartment syndrome occurred and 4 cases underwent open decompression.

The internal fixation group included 42 patients with severe complicated tibiofibular fractures treated by internal fixation from January 2011 to March 2017, including 33 males and 9 females aged 17 to 70 years (mean 40.3 years old). There were 26 cases of traffic injuries, 10 cases of heavy bruises, 6 cases of high fall injuries, 22 cases of open fractures (according to Gustilo classification: 12 cases of type II, 10 cases of type III), 20 cases of closed fractures (according to Tscherne classification: 13 cases of grade 2, 7 cases of grade 3). According to fracture line classification, there were 16 cases of transverse fracture, 9 cases of oblique, 6 cases of spiral, 7 cases of comminuted, and 4 cases of multiple fractures. According to the location of fracture, there were 11 cases in the proximal one-third, 9 cases in the middle one-third, 14 cases in the middle and distal junctions, and 8 cases in the distal one-third. Compartment syndrome was treated with incision decompression in 6 cases. There were 18 cases treated with steel plates and 24 cases treated with intramedullary nails.

Inclusion Criteria and Exclusion Criteria

Inclusion criteria were the following: (1) high-intensity injury resulting in severe soft tissue injury or open severe complex tibiofibular fracture, Gustilo type II-III or Tscherne grade 2-3 and (2) follow-up time ≥6 months. Exclusion criteria were the following: (1) Simple low-energy tibiofibular fracture, Gustilo type I or Tscherne grade 1. (2) Total tibial plateau, pilon fracture, and other cumulative articular surface fracture patients. (3) Follow-up time <6 months. (4) Cases involving serious internal medicine. (5) Patients with interruption of follow-up or impaired case data. Finally, (6) patients with severe neurovascular injury.

Surgical Methods

TSF Group

Epidural anesthesia is often used in the TSF group, and general anesthesia can be used in patients with other combined injuries. The patient is often placed in a supine position to reduce ischemia and reperfusion injury; it is generally not recommended to use a tourniquet. Open wound treatment involves the following: emergency (6 to 8 hours) wound debridement, Taylor frame fixation, for a small wound surface; if contamination is not serious, the wound can be closed in one stage; if the wound is large, heavy contamination can be removed with a vacuum sealing drainage (VSD) negative pressure device. A second-stage skin graft or flap transfer is used to close the wound. Closed fracture treatment involves the following: generally, you do not need to wait for the swelling to subside; rather, the fracture can be fixed in the early stage of the Taylor frame, resulting in early exercise of the limbs, and gradual exercise after 2 to 3 weeks.

The Taylor external fixator installation procedure is the following: after the affected limb is sterilized, the C-arm machine monitors the axial traction of the distal end of the affected limb, roughly resets the fracture end displacement (shortening, angulation, and rotational displacement), and initially restores the length of the tibia. Cantering on the fracture line, a TSF ring is inserted into the distal and proximal fractures (if the fracture segment is ≥3 cm, ensure that each fracture segment is fitted with one ring, because the TSF ring and the tibia are placed ≥2 cm from the fracture line). When the anatomical axis is vertical, at least 2 full needles or olive needles are inserted into the safety channel of each level of the tibia, and connected with the TSF ring. If the stability is poor, a half needle can be implanted to increase stability and, according to the adjacent TSF ring, install 6 adjustable connecting rods. Under the perspective of the C-arm machine, the fracture displacement parameters were preliminarily calculated and the fracture was repaired by adjusting the 6 connecting rods. If the fracture is difficult to reset and the local soft tissue can be finitely cut at the fracture end, a comminuted fracture can be transformed into a relatively simple fracture by temporary fixation with Kirschner wire or by using plate fixation to maximize the recovery of the bone shaft. The tubular morphology was further reset after surgery with computer software.

Internal Fixation Group

The anesthesia method and the surgical position of the internal fixation group are the same as in the TSF group. Open fracture emergency (6 to 8 hours) wound debridement is performed, followed by temporary external fixation of the fractured unilateral outer frame; if there is a small wound surface and contamination is not serious, the wound can be closed in one stage; if the wound is large and contamination is heavy, VSD negative pressure is used and a second-stage skin graft or flap transfer is used to close the wound. After the soft tissue recovers, open reduction and internal fixation are performed. After the swelling of the closed fracture subsides (indicated by the appearance of dermatoglyphics) and the local soft tissue recovers, open reduction and internal fixation are performed once tension blisters have subsided. The open reduction and internal fixation process is the following: the surgical approach is determined according to the soft tissue condition and the type of fracture. In the process of fracture reduction, as much as possible is done to protect and reduce soft tissue damage, including avoiding using long incisions to pursue excessive anatomical reduction. For the reduction, it is required to fully reduce the longitudinal, axial, and rotational displacement of the tibia.

Postoperative Treatment

In the TSF group, the standard lateral radiograph was improved. The fracture displacement parameters were measured according to the x-ray film. The parameters were input into the TSF computer software system, and 6 adjustable connecting rods were used to make adjustments. After the fracture was reset, the film was reviewed again. If the reset was not good, the fracture displacement parameter could be measured again and imported into the computer software to adjust the parameters again until ideal. Postoperative nail dressing and regular dressing care were provided. Knee and ankle joint functional exercise began the first day after surgery, with gradual weight-bearing 2 to 3 weeks after surgery, and a monthly review following filming; the external fixator was dismantled after the fracture healed.

When evaluating fracture reduction and fixation, the internal fixation group had an improved positive lateral radiograph. After the operation, the affected limb promoted blood return. On the second day, active and passive functional exercises of the knee and ankle joints were increased. Regular incision dressing was provided (if the wound dressing had exudation, the dressing was changed), and the wound was not bandaged after exudation. The incision healing was complete 10 to 14 days after surgery. If the wound became infected, the secretion was assessed in the laboratory for bacteria, and an antibiotic was intravenously provided according to the result; the drug was changed frequently, and if necessary, vacuum suction treatment was used. The patient avoided weight-bearing activities for 6 weeks after surgery, and then gradually added weight with the help of progressive ablation. In this study, the x-ray films were reviewed in January, February, March, and June. One year later, fracture healing was judged according to the films. After the fracture healed, the internal fixation was removed.

Observation Indicators

The main follow-up details recorded were the patient's surgical preparation time, operation time, fracture healing time, total weight-bearing time, length of hospital stays and expenses, postoperative complications, as well as other indicators.

Statistical Methods

We used SPSS Statistics software (Version 21.0; SPSS Inc) for the following statistical analysis: the categorical variable data was analyzed by chi-square test, the countable data was analyzed by t test, and the test standard was α=.05.

Results

Clinical Follow-up Results of the TSF Treatment Group

All 28 cases were followed up for an average of 23.5 months (range 10-48 months); the average preoperative preparation time was 3.5 days (range 0.5-8 days); the average operation time was 112.3 minutes (range 90-131 minutes); and 4 cases of bone defects occurred. Bone grafting and internal fixation were used to obtain healing. In 3 cases of delayed fracture healing, late adjustment of the external frame fracture resulted in good healing. The fracture healing rate was 85.71%, with an average fracture healing time of 20.3 weeks (range 16-48 weeks). The external fixation frame was worn for an average of 26 weeks (range 17-48 weeks). Overall, 4 cases of compartment syndrome occurred, emergency decompression was given, the TSF external fixation frame was installed after the wound was closed, and the patient was discharged after adjustment and resetting. The average weight-bearing time was 90.5 days (range 65-180 days); the average number of days spent in hospital was 10.8 days (range 6-24 days); and the average hospitalization cost was 5.6 million (range 3.8-97 million). Postoperative wound infection occurred in 2 cases, and 13 cases occurred in the needle. Infections were cured after wound dressing and oral antibiotics. No cases of chronic osteomyelitis occurred. In 1 case, there was another fracture after the removal of the external frame, and the fracture was healed after internal fixation. At the last follow-up, all patients could step onto the ground and 21 patients could participate in daily housework. There were no patients with joint stiffness.

Clinical Follow-up Results of the Internal Fixation Group

A total of 42 patients were followed up for an average of 19.5 months (range 7-34 months). This included 18 patients in the plate fixation group and 24 patients in the intramedullary nail fixation group. The average preoperative preparation time was 10.5 days (range 6-24 days) and the average operation time was 152.4 minutes (range 120-185 minutes). Overall, 3 cases of nonunion occurred, which healed after internal bone grafting. In total, 4 cases had delayed fracture healing. The fracture healing rate was 92.86% and the average fracture healing time was 23.8 weeks (range 17-54 weeks). A total of 6 cases of compartment syndrome occurred; acute incision decompression was provided and internal fixation was performed after the closure of the wound. All healed well and the average time to weight-bearing was 110.3 days (range 60-185 days). The average hospital stay was 18.2 days (range 14-33 days) and hospitalization costs averaged 6.2 million (range 5.3-11.2 million). Postoperative wound infection occurred in 20 cases; infections were cured after dressing change, intravenous antibiotic, and/or VSD negative pressure treatment. In total, 5 cases of chronic osteomyelitis occurred. One patient’s bone fractured after internal fixation. There was no joint stiffness among patients.

Comparison of the Efficacy of TSF and Internal Fixation in the Treatment of Severe Tibiofibular Fractures

The fracture healing rate was 85.71% (24/28) in the TSF treatment group and 92.86% (39/42) in the internal fixation group (Table 1). In the TSF treatment group, the time spent on preoperative preparation time, operation time, fracture healing time, total time to full weight-bearing, and hospitalization stays were shorter than those in the internal fixation group, and the hospitalization cost was lower; the difference was statistically significant (P<.05).

Comparison of Postoperative Complications Between the TSF and Internal Fixation Groups

The incidence of postoperative infection and osteomyelitis was lower in the TSF group than in the internal fixation group (P<.05). There was no significant difference in the probability of nonunion and refracture (P>.05; Table 2).

Typical Cases

Figures 1 and 2 showed the open fracture of left tibia and postoperative recovery of patient A.

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Case-Related Information

Clinicians at an external hospital completed the wound debridement and closure. Later, in our hospital, the soft tissue injury was found to be considerable. The preoperative x-ray showed a fracture. The third day of admission, TSF external fixation was performed. Software-assisted adjustments were performed to achieve a good reduction of the fracture end. Finally, 10 months later, a review of computed tomography scans showed good fracture healing; the affected limb had normal function 11 months after the removal of the outer frame.

Figure 3 showed the comminuted fracture of the left tibia of patient B with severe soft tissue injury. Figures 4 and 5 showed the patient's TSF treatment and postoperative recovery.

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Patient-Related Information

The patient was 48 years old. A car accident caused injuries of the left tibia including severe soft tissue injury and three comminuted fractures (Tscherne grade 3). The lateral position of the left tibia showed three fractures of the proximal, middle, and distal bone, and the proximal and middle fractures were clearly displaced. On the fourth day of admission, the proximal and middle fractures were treated with TSF external fixation, the distal fracture was fixed with internal fixation, and a lateral x-ray was performed. After the operation, soft tissue damage was severe and many tensional blood vessels could be seen; in addition, the anterior tibial skin was black and necrotic. Combined with the TSF computer software, the positive lateral radiographs after fracture reduction were good. Finally, 11 months after the operation, the skin was restored to a good condition with soft tissue treatment such as skin grafting. The limb functioned well 20 months after surgery, and knee joint function was good.

Discussion

Principal Findings

In trauma orthopedics, tibiofibular fractures are common, accounting for about 12% of total long bone fractures. The prognosis after fracture is affected by the energy level of the injury. When the damage energy is higher, the probability of an open fracture, the degree of fracture complications, and the degree of soft tissue injury increase accordingly, increasing the incidence of postoperative complications. High-energy damage is mainly seen in traffic accidents, falls from high places, and direct injuries by heavy objects. In contrast, low-energy injuries are more common in sports (about 80.1%) and regular falls. As countries develop, there is a corresponding increase in the incidence of traffic accidents, leading to an increase in high-energy fractures. Since there are fewer subcutaneous tissues on the anterior aspect of the lower leg, these fractures are prone to be open fractures, and account for 9.72% to 13.7% of open fractures.

An epidemiological survey of 523 cases of tibiofibular fractures showed that 400 cases (76.5%) involved closed fractures and 123 cases (23.5%) involved open fractures [4]. These were a result of traffic accident injuries (37.5%), falling (17.8%), sports (30.9%), and beatings or direct hits (4.5%). The majority of the blood supply of the tibia is provided by the nourishing artery. This artery enters the tibia from the upper one-third, and the trophoblast descends into the skeletal cortex. In a fracture, most of the arteries providing cortical nourishment are broken, resulting in insufficient blood supply to the distal one-third of the tibia, which slows down healing and is not conducive to the patient’s recovery. There are many treatment methods for tibia fractures, each with its own advantages and disadvantages. The choice is mainly based on the way the injury occurred, the fracture type, other injuries, and the patient’s condition. Gypsum or splint fixation is generally suitable for stable fractures from a low-energy injury and those without obvious displacement. Due to the risk of calf compartment syndrome and venous thrombosis, it is currently used for fractures of the tibia. If there is a lower risk of calf compartment syndrome and venous thrombosis, there is less indication that the fracture was caused by a high energy injury.

Open reduction and internal fixation treatment can achieve good fracture reduction, which is beneficial for early functional training of the limb. The intramedullary nail is currently the preferred treatment for humerus shaft fractures. This technique has many advantages and a long history in the treatment of tibial fractures. It has a central fixed biomechanical advantage, involves a minimally invasive operation away from the fracture end, retains the hematoma at the fracture end, and involves less soft tissue exfoliation, which is conducive to fracture healing. Therefore, it is widely used in clinical practice. However, any given treatment is not perfect, and the intramedullary nail still has its limitations. In a previous study, 32 cases of proximal humeral fractures were treated with intramedullary nails and the malunion rate was 19%, indicating the treatment was not satisfactory [5]. Kumar et al [6] compared the biomechanical characteristics of the treatment of tibiofibular fractures with steel plate, interlocking intramedullary nail, and external fixation. The results from the intramedullary nail treatment are better than those of the other two techniques, but this treatment is associated with malunion.

The orthopedic surgeon’s philosophy of fracture treatment has gone from Association for the Study of Internal Fixation (AO)-led anatomical reduction to strong internal fixation to the promotion of biological fixation. The four principles of treatment of fractures as proposed by the AO concept are as follows: (1) anatomical reduction, (2) compression fixations at the fracture end, (3) protection of blood supply, and (4) early functional exercise. Early dynamic compression plate (DCP) treatment increased friction at the end of the fracture through the compression of the fracture end, and achieved first-stage healing of the fracture. The DCP is in close contact with the bone, and the fracture is stabilized by increasing friction, which destroys the blood supply at the fracture end. Influenced by the AO concept, many orthopedic surgeons remove large amounts of soft tissue to destroy blood supply and achieve anatomical reduction. Strong fixation causes stress shielding, and the bone is prone to refracture after the removal of internal fixation. The concept of biological fixation puts more emphasis on the protection of local soft tissue and the blood supply of the fracture.

The biological fixation principle is as follows. First, fracture reduction is performed as far as possible from the fracture end, to protect local soft tissue. To minimize soft tissue dissection, comminuted fracture block reduction cannot excessively destroy the blood supply. Fracture fixation involves a low elastic modulus and good biocompatibility. The contact area between the built-in material and the bone surface is minimized, avoiding excessive fixation and causing stress to discourage refracture. The patient is preoperatively fully evaluated and there is a preoperative design process, which shortens operation time and reduces surgical exposure.

Through the transformation of the fracture fixation concept and related biomechanical research, the locking compression plate (LCP) came into being. It combines two completely different fixation techniques, both a compression plate as well as steel plates and nail tails. The locking component between them is used as an inner bracket. The LCP provides both angular and axial stability to prevent the screws from slipping. In one study, 28 patients with fractures of the lower tibia were treated with DCP and 20 patients were treated with LCP [7]. The fracture healing time was 16.2 months for DCP and 15.4 months for LCP. The LCP effect was better than the DCP result.

In another study, 25 cases of tibiofibular fracture were treated with the minimally invasive percutaneous plate osteosynthesis (MIPPO) technique, which is considered safe and effective [8]. The most ideal fracture treatment should be as minimally invasive as possible and avoid the use of implants such as steel plates and intramedullary nails. The internal fixation treatment is beneficial for the anatomical reduction of the fracture, but at the same time, this invasive operation increases the risk of infection. Due to the development of internal fixation equipment and the improvement of fracture fixation, the results of internal fixation for the treatment of severe tibial fractures have been greatly improved. However, due to the high incidence of complications such as postoperative infection and osteomyelitis, the combination of open and severe soft tissue injury, and the treatment of multiple comminuted fractures and infected tibiofibular fractures, this technique is challenging.

External fixation is a good solution to the abovementioned shortcomings of internal fixation in the treatment of severe tibial fractures. The external fixator is simple to install and the technique is easy to learn. It causes minor secondary damage to soft tissue and can be used for early fixation of open tibiofibular fractures or fractures with severe soft tissue injury. It is beneficial for the early care of the affected limb, such as functional exercise, adjacent joint function, and exercise. This study compared the postoperative complications of TSF external fixation and internal fixation in the treatment of severe complex tibiofibular fractures (Table 2). The incidence of postoperative wound infection and osteomyelitis was significantly lower in TSF than in the internal fixation group (P<.05), and there were no significant differences in the rates of delayed fracture healing, nonunion, and refracture. A study by Herrera-Pérez et al [9] included a total of 14 internal fixation and external fixation cases for the treatment of severe tibial fractures. A meta-analysis showed that the difference in the rate of refracture following either external or internal fixation was not statistically significant. The 41 patient cases in this study showed that external fixation was better than internal fixation in the treatment of open tibial fractures.

The commonly used single-sided and half-needle external fixator is quick and easy to operate, and is often used for postdebridement fracture fixation of open fractures. However, its fracture stability is not ideal, so it is also often used for temporary fixation, and other fixation methods are used later on. Sabesan et al [10] reported that patients over 12 years of age with humeral shaft fractures were treated with a unilateral external fixator due to the risk of lost fracture reduction.

In this study, 28 patients with severe tibiofibular fractures were treated with TSF and achieved good results (a fracture healing rate of 85.71%). TSF can achieve early and accurate reduction of fractures aided by a computer. TSF can be the final method of fracture fixation due to good fracture stability. It enables the precise treatment of tibial fractures caused by complex high-energy injuries. This study compared the preoperative preparation time, operation time, fracture healing time, total time to weight-bearing, hospitalization days, and other outcomes of TSF and internal fixation in the treatment of tibial fractures. The operation and healing times of the TSF group were shorter than in the internal fixation group [11].

The authors’ experience in the treatment of complex tibial fractures with TSF includes the following insights: postoperative computer-assisted adjustment of external frame fractures requires the addition of two parallel links on both sides of the outer ring to increase stability; it is important to measure the fracture displacement parameters; the distance between the proximal and distal rings in the TSF installation process needs to be prejudged to avoid the longest distance between the two rings being greater than the longest model connecting rod, or shorter than the minimum model connecting rod, as the short length makes postoperative resetting impossible. Overall, our experience shows that TSF is effective in treating patients with severe tibial fractures caused by high-energy injuries. Compared with the internal fixation method, the incidence of postoperative wound infection and osteomyelitis was reduced. TSF can enable early fracture fixation surgery and early functional exercise, shorten hospitalization time, and reduce treatment costs.

Conclusions

TSF has a low complication rate, with the advantages of fracture closure and accurate reduction, providing a new treatment method for complex tibiofibular fractures. Compared with the internal fixation method, it has a shorter preoperative preparation time, operation time, fracture healing time, and total time to weight-bearing, as well as shorter hospital stays and lower hospitalization costs for the treatment of severe complex tibial fractures. There is a lower chance of complications such as postoperative infection and osteomyelitis, and there is no significant difference in the incidence of nonunion, delayed healing, and refracture.