Introduction
Diaphysis is the most common site of fracture in the tibia and about 80% of these injuries have associated fibular fractures at the same or different level. However, it is possible that fibula fracture may not occur with tibia fracture in low energy injury.1 Around 26 tibial diaphyseal fractures per 100,000 of the population per year seen in the average population. The average age seen in the tibial shaft fracture population was about 37 years.2 Isolated tibial shaft fractures with intact fibula are a fairly common injury. Hospital records often fail to mention the intact fibula in such injuries. Compared to fractures elsewhere in the body, tibial fractures have relatively high rates of nonunion and malunion.3 Many studies blame the intact fibula for the cause of complications associated with the management of tibia fractures like delayed union, non-union, and malunion.4 With an intact fibula, tibio-fibular length discrepancy develops and causes altered strain patterns in both tibia and fibula leading to delayed union, nonunion, or malunion of tibia leading to a sequel of joint disturbance.5 Historical descriptions of the treatment of tibial fractures are included in the Edwin Smith Papyrus, an ancient Egyptian medical text dating back to at least 1500 to 1600 BC.6 Intramedullary interlocking nailing has become a gold standard choice.
Materials and Methods
To compare outcomes in terms of duration surgery, rate of union, malunion, delayed union, non-union when closed tibial shaft fracture managed with reamed intramedullary nailing in a patient with intact fibula versus fractured fibula.
The study was conducted at the Department of Orthopaedics, in our institute for duration of 1 year. All patients underwent closed reduction and intramedullary interlocking nail for tibial shaft fracture with or without fibula fracture. Ethical clearance was obtained from the institutional ethics committee (human) of the institute before starting the research.
Nail length measurement
We followed the method of tubercle medial malleolar distance by measuring the length between the most prominent points on the medial malleolus and the tibial tubercle. The diameter of the nail was assessed by measuring the tibia at its narrowest point, which was best appreciated on lateral radiographs.
Procedure
Nailing was done using a standard radiolucent operating table. The patient was placed supine under spinal anaesthesia with the injured leg was positioned freely, with the knee flexed at 90° with padded support over the edge of the operating table. Surgical Draping was done with 10% betadine from the distal part of the femur covering the knee joint up to all toes of the fractured limb and the foot part was covered with sterile gloves /sterile cloth. In our cases, we commonly used the medial parapatellar approach. After selecting the ideal point of insertion at just medial to the lateral tibial spine which we had determined from a true AP radiograph using C-arm as the amount of tibial rotation had been shown to affect the appearance of the guide wire location by as much as 15 mm, Therefore, it was important that a “true” AP of the knee was used to determine the starting point. This view was obtained by ensuring that the fibula was bisected by the lateral aspect of the tibia at the joint. Once the starting point was correctly placed, curved bone awl was used to breach the proximal tibial cortex and then ball tip guide wire of length 3 mm diameter x 950 mm was advanced in the appropriate direction. The guide wire was passed into the medullary canal anterogradely across the fracture site after closed reduction with image intensifier guidance. Serial reaming will be done in increments of 1 mm. A nail of the measured length and diameter which was 1 mm less than the last reamer was mounted in the jig and negotiated down the medullary canal and across the fracture. The distal locking was done by freehand technique with the help of an image intensifier. Proximal locking with one or two screws was done using the jig.
Postoperative
The patients were given intravenous antibiotics for five days and oral antibiotics up to the day of stitch removal. A check x-ray was taken immediately after the surgery. Sutures were removed on the 14th day. Physiotherapy was started with active quadriceps strengthening, range of motion, and non-weight-bearing ambulation with the support of axillary crutches, and patients were followed up at 6,12, and 24 weeks and assessed for subjective, clinical, radiological signs of union and ability to do strenuous activity. Fracture union was considered when the patient bears full weight without pain; the fracture site not tender on palpation and the radiograph shows osseous union. Finally, the functional assessment was done at 6 months using Johner and Wruh’s criteria (Table 1) and radiological assessment at 6 weeks, 12 weeks, 24 weeks using RUST score7 (Table 2). RUST scoring was a radiographic evaluation method with high repeatability and reliability, which was used for tibial shaft fractures applied with intramedullary nailing. A RUST score ≥9 was accepted as union.7
Statistical analysis
The statistical analysis of data was performed using the computer program, Statistical Package for Social sciences (SPSS for Windows, version 20.0. Chicago, SPSS Inc.) And Microsoft Excel 2010. Results on continuous measurements are presented as mean + standard deviation are compared using the student’s t-test. Discrete data are expressed as numbers (%) and are analyzed using the Chi-square test and Fischer’s exact test (where the cell counts < or 0). Pearson’s correlation coefficient (r) was used to measure the associations among continuous variables. For all analyses, the statistical significance was fixed at a 5% level (p-value <0.05).
Results and Observation
A total of 59 patients were divided into two groups, Group (IF) (n =26) isolated tibial shaft fracture and Group (FF) (n = 33) tibial shaft and fibula fractures. The mean age was 29.38 years in group IF and 30.09 years in group FF. 69.49% of the total study population were male patients. RTA was the most common mode of injury in group FF whereas in group IF, 46.15% of patients sustained falls. The right side was commonly involved in both the group. In both groups, middle 1/3rd diaphyseal tibial fracture was commonly observed. Among the group IF according to AO classification 42B2.1 was common with 8 patients among 26 (30.77%) (Figure 1). Among the group FF according to AO classification 42A3.3 (transverse fracture of tibia with a fibular fracture at the same level) was common with 8 patients (26.67%) and tibia fracture with a fibular fracture at the same level (42A1.3+42A2.3+42A3.3+42B1.3+42B3.3)=3+5+8+1+4=21 (63.63%) which was commonly noted in our study (Figure 2 ).
Secondly lower 1/3rd tibial diaphyseal fracture was observed in 3 patients (11.54%) in group IF and 6 patients (18.18%) in group FF. The time interval between the day of trauma to the day of surgery in group IF was an average of 3.31 days and in group FF average was 3.55 days. The mean duration of surgery in group IF was 106.62 minutes wherein group FF was 97.91 minutes The radiological union was early with a mean union rate of 19.09 weeks in group FF compared to group IF where the union rate mean was 22.23 weeks. (Table 4) The final functional outcomes in both the groups were derived by using Johner and Wruh’s criteria (Table 3) Radiological Union was evaluated according to the RUST criteria (Table 4). In our study, none of the cases went into malunion and deformity in group IF. The percentage of nonunion was 3.85% in group IF and there was no case of nonunion in group FF. Percentage of the delayed union in group IF was 19.23% whereas in group FF was 6.06%. At 6 months due to delayed union in 5 cases of group IF dynamization was done in 3 cases and bone marrow injection in 2 cases. In the 9th month, a case of nonunion was treated with fibular osteotomy, and the union was obtained (Figure 7). The percentage of infection was 7.69% in group IF whereas in group FF it was 3.03 percentage. In group IF the percentage of a screw breakage was 7.69% but in group FF it was 9.09%. In group IF there was 19.23% with anterior knee pain as a complication compared to group FF which had 9.09%. In group FF four patients had malunion and deformity, in all four cases, the level of tibia fracture was lower 1/3 diaphyseal with fibula fracture at the same level (Figure 6) compared to group IF where there was no deformity. (Table 4)
Figure 3
Group FF – preoperative & 6 weeks, 3 months (lower left corner) and 6 months (lower right corner)
Table 1
J&W criteria
Table 2
RUST criteria
Table 3
Clinical evaluation
Table 4
Results
Discussion
Intramedullary nailing is accepted as the gold standard method of treatment in closed tibial shaft fractures. Still, there is a debate on how a tibial fracture with concomitant fibula fracture or intact fibula should be treated. An intact fibula seems to interfere with the healing of ITS fracture by preventing effective compression at the fracture site as one of the essential features in the healing process is a physiological cyclical application of weight-bearing forces across the fracture.8 Duration of surgery was measured from the time of incision to suture. Madhukar K.T et al in their study observed that intraoperative reduction of tibia fracture was difficult when the fibula was intact, especially tibia was grossly displaced.9 In our study, we also experienced similar difficulty in tibial fracture reduction intraoperatively when the fibula was intact hence the duration of the surgery in group IF was more with an average of 106.62 minutes when compared to group FF where it was only 97.91 minutes. The most significant finding of the current study was that when there is an intact fibula, the union of the tibia fracture is delayed while malalignment is prevented. An intact fibula can cause distraction in the fracture line during intramedullary nailing of tibial fractures. It has been reported that 5 mm distraction of the fracture line in tibial fractures can prolong union to 8-12 months.10 Isolated tibial fractures have been examined in literature and it has been reported that union problems have been experienced.11 In a study by Court-Brown et al isolated tibial fractures were compared with cases of both bone fractures and a significant difference was determined in the time to union (16.7 weeks vs.15.6 weeks).12 Balaji et al. found the time to union to be mean 19.7 weeks in 56 cases of isolated tibial fracture with an intact fibula.13 In the current study, the meantime to union was determined as 22.23 weeks in Group IF and 19.09 weeks in Group FF (p< 0.001). The intact fibula was observed to have prolonged the time to union. Although there is no time limit for non-union in tibial fractures, a delayed union is said to be a union occurring at 3-4 months, and non-union is accepted as no union within 6-8 months. In the current study, the non-union rates according to the 6-month RUST scores were determined to be average score of 9.35 in Group IF and 10.27 in Group FF. The difference between the groups was statistically significant (p = 0.021). The anatomic fibula was observed to have delayed union of the tibial fracture. At 12 months postoperatively, non-union was observed in 1 patient in group IF. Malalignment is often seen in distal tibial shaft fractures with a concomitant fibular fracture at the same level. In the current study, malalignment was observed in 4 patients in Group FF and none of the cases went to malunion in the intact fibula group. The anatomic fibula was found to have reduced malalignment. In a study by De Giacomo et al of 122 patients with distal tibial fracture applied with intramedullary nailing, malalignment was observed mostly in patients with a fibula fracture at the same level as the tibial fracture.14
Conclusion
Tibia fracture with concomitant fibular fracture was a far more common injury compared to isolated tibia fracture. Although these two types of injury were common at any age group the mode of injury still differs. High energy trauma was the common cause of both tibia and concomitant fibula fracture whereas isolated tibia fractures were caused by low energy trauma. The displaced isolated tibial fracture was difficult to reduce intraoperatively leading to prolonged operative time compared to both bone fractures of the leg. A longer duration of the radiological union was observed in isolated tibial fracture compared to the other. Nonunion and delayed union were significantly noted in the isolated tibial fracture. The functional outcome remains the same between the two. Among the various complications, there were cases of deformity in the distal one-third of diaphyseal tibial fractures with a fibular fracture at the same level.
Limitations
Limitations of the current study can be said to be the low number of patients and that the groups were not equal in number. In addition, other factors affecting unions were not compared (smoking, socioeconomic status). With such methodological limitations, the interpretation of this study remained limited. Therefore, further multicentered, randomized controlled studies on a larger sample size with long-term follow-up should be implemented to conclusively ascertain the outcomes.