Management of open fractures is a surgical urgency comprising debridement of devitalized and contaminated tissues, stabilization of fractured bones, and timely administration of appropriate antibiotics ^[1,2]. Achieving fracture union and optimum function may involve multiple surgeries depending on the extent of contamination, bone and soft-tissue loss, and development of complications. The initial procedure is the key, as an adequate debridement substantially reduces the risk of development of infection and must be performed by an experienced team ^[2]. Delayed presenting open fractures are complex problems, as the golden opportunity of early debridement and fracture stabilization has already been missed, and it is not infrequent for the infection to have been established by the time of any surgical intervention in most cases. Similarly, inadequate initial debridement, failure to recognize the necessity of subsequent serial debridements, or poor care of external fixator pins can lead to persistent infection, thereby making the subsequent treatment difficult. Although the principles of management remain the same as for open fractures, the overall risk of chronic osteomyelitis and fracture nonunion is increased in such cases. In these patients, the goal of treatment is to eradicate the infection and to achieve fracture union with optimum limb function. Initial fracture stabilization can be done as a temporary measure with an external fixator or internal fixation with an antibiotic-coated implant or antibiotic-impregnated cement spacer till the infection subsides; this can be followed by an exchange to a better definitive fixation device. Otherwise, an external fixation system can be used as a definitive modality (Ilizarov ring fixator and monorail system) ^[3]. The second strategy is useful in cases with bone loss ^[4,5]. Either strategy has its advantages and disadvantages. However, irrespective of the approach adopted, the overall cost of treatment and the patient’s tolerability are always important considerations. In our own experience with delayed presenting cases with established infection, we have had a very high incidence of persistent infection leading to chronic osteomyelitis when internal fixation was used following initial debridement, even when performed as a staged procedure. A locking compression plate (LCP) used as an external fixator (supercutaneous plating) has produced satisfactory outcomes in open/closed tibial fractures and infected nonunion of the tibia, clavicle, and humerus, overcoming the shortcomings of traditional external fixators ^{[6,7,8,9,10,11,12,13]}. It has the advantages of being located on one side of the limb, being easier to apply, and being less bulky, leading to greater patient tolerability ^[8,9]. The purpose of this study was to evaluate the functional and radiological outcomes of treatment of delayed presenting open extra-articular lower limb fractures complicated with infection using locking plate external fixators as a definitive fixation modality.

This prospective study was conducted between February 2018 and November 2019 after obtaining approval from the departmental review board at our institute, which is a tertiary care referral center. Informed consent was obtained from all patients before inclusion.

Inclusion criteria

Patients were included if they had been primarily managed at another hospital and were referred to or presented independently at our institute. Inclusion required the absence of intra-articular extension, no bone loss necessitating bone transport, and the planned plate position not interfering with wound management.

Pre-operative and surgical procedure

No pre-operative antibiotics were administered. Under spinal anesthesia, thorough debridement of the infected open wound was performed. Multiple deep intraoperative cultures were taken. In simple fractures, bone ends were trimmed to achieve at least 50% apposition. In comminuted or segmental fractures, all viable bone fragments with attached soft tissue were retained after adequate debridement. For tibial fractures, a stainless steel 4.5 mm proximal tibial metaphyseal plate was applied to the anteromedial surface (Fig. 1).

Figure 1: Case 1- pre-op X-rays.

For femoral fractures, a distal femoral metaphyseal plate was applied to the lateral surface. External fixator principles were followed, using long plates and bicortical screws. Temporary stabilization with K-wires was achieved before definitive plate application. A one-finger breadth distance was maintained between the plate and the skin. A minimum of three screws were placed in the longer fragment and four in the shorter fragment, with the most proximal and distal screws applied first to ensure correct plate positioning. For femoral applications, cruciate incisions were made in the iliotibial band around the screws to prevent tethering during knee flexion. In seven cases, reused plates were applied after autoclaving; however, fresh screws were used in all cases.

Post-operative management

Antibiotics were administered according to culture and sensitivity reports for a total of 6 weeks – 2 weeks of intravenous antibiotics followed by 4 weeks of oral antibiotics. Wound care involved daily dressing with normal saline until healing was complete. Screw tracks were cleaned daily with normal saline during hospitalization. Among the cohort, only one patient with a proximal tibial fracture required a split-thickness skin graft to cover a wound defect on the lateral upper third of the leg. No other patients required flap procedures. Upon discharge, patients were educated on wound care and hygiene. Once complete wound healing was confirmed, patients were allowed to shower with the external fixator in place. Supervised physical therapy using a continuous passive motion (CPM) machine was initiated on post-operative day 2 and continued throughout hospitalization. Depending on the stability of fixation, toe-touch or partial weight-bearing was encouraged from 4 to 6 weeks postoperatively.

Follow-up and outcome measures

Between 6 and 12 weeks, plate dynamization was performed by removing a screw near the fracture site to promote progressive weight-bearing as healing advanced. Plate removal was conducted in the outpatient setting on radiological confirmation of fracture union (Fig. 2).

Figure 2: Case 1 – post-operative X-rays showing radiological union.

Follow-up assessments included anteroposterior (AP) and lateral radiographs at 6 weeks, 3 months, and every 6–8 weeks thereafter until fracture union. An orthoscanogram (bilateral lower limb AP view) was performed after plate removal to assess coronal plane alignment. Lack of fracture callus at 12 weeks was an indication for autologous bone grafting. Functional outcomes were evaluated using the Knee Society score 2 weeks after plate removal (Fig. 3). Screw track infection was diagnosed clinically by the presence of increased pain, redness, and purulent discharge around the screw site.

Figure 3: Case 1 – post-operative range of motion achieved.

A total of 15 patients underwent cutaneous plating of the tibia and femur fractures using a metaphyseal locking plate (Fig. 4 and 5).

Figure 4: Immediate case 2 post-operative X-rays.

Figure 5: Case 2 follow up X-rays showing radiological union.

Table 1: Patient demography and diagnosis

Table 1 summarizes the patient data. All patients were followed for a mean of 9 months (range 6–12 months). The time between injury and definitive surgery was 1.4 months (range 15 days to 5 months). At presentation, all of them had an active purulent discharge from the wound over the fracture site with pin tract infection in patients with an external fixator. Four patients requiring this procedure had distal femur fractures, and the rest 11 patients had tibia fractures. The average union time was 8 months in the distal femur group (Fig. 6)

Figure 6: Case 2 – post-operative X-rays after implant removal – lateral.

and 3.9 months in the tibia group. Two patients (one each with femur and tibia fractures) needed an autologous iliac crest bone graft to augment the fracture union (Table 1). The knee society score was excellent in 4 (26.6%), good in 7 patients (46.66%), fair in 3 (20%), and poor in 1 (6.67%) patient; the details are summarized in Table 2. All patients with a fair or poor score had a distal femur fracture (Fig. 7).

Figure 7: Case 2 – post-operative range of motion achieved.

In three patients, the infection-causing microorganism (Escherichia coli) was resistant to all tested antibiotics except cotrimoxazole. In two of them, the infection subsided with another debridement within a week. The third patient underwent a 3^rd debridement to eradicate the infection. Six patients had a screw tract infection at some point during the treatment (12 incidences). Swabs were taken for microbiological analysis. They were treated with regular dressing and local ciprofloxacin eye drop application with a course of appropriate intravenous or oral antibiotics. The painful screws were removed if the fracture showed signs of healing and the overall stability of the construct was adequate. No loosening or failure of the implant was observed in any patient. One patient (distal femur group) had shortening of 5 cm as compared to the contralateral limb post repeated debridement and was prescribed a shoe raise for ambulation. One patient developed a repeat fracture 2 weeks after plate removal. A review of the radiographs just before plate removal showed that the callus formation was deficient on one side. As the fracture was incomplete, it was treated with a high groin cast, and the fracture finally healed in 2 months. Table 2 presents the details of the complications encountered in the course of treatment.

Table 2: Time for union, knee society score and complication

Since its first description by Kloen ^[6], many authors have described the use of LCPs as an external fixator. Although the plates are not designed to be used in this manner, the ease of application, low complication rates, and the predictable outcome have enhanced their acceptability among orthopedic surgeons. Our study shows that using locking plates for external fixation is a suitable option for treating patients with open long bone fractures with established infection who have presented late. The bony union is predictable if a good fracture apposition can be achieved along with eradication of infection, which may need serial debridement. Previous studies have shown that external locked plate fixation can be a feasible option for definitive treatment of tibia fractures from a biomechanical viewpoint ^[11,14,15]. These findings have been reciprocated in multiple clinical studies with satisfactory radiological outcomes ^{[8,9,10,12,16]}. In 7 proximal tibia fractures, we used a proximal tibial metaphyseal plate. Ma et al. advocated the use of a femoral metaphyseal plate for proximal tibial fractures as it is relatively straight ^[11]. Although we did not have any difficulty in screw positioning due to the proximal curvature of the plate, as the proximal tibia is wide enough. For distal femur fractures, we used a femoral metaphyseal plate. In distal femur fractures, because of limited bone in the distal fragment, only a ring fixator can provide adequate multiplanar stability without spanning the knee joint until the union is achieved. This is technically demanding and requires familiarity with Ilizarov techniques. Since there was no bone loss in our cases, we decided to do supercutaneous plating as an alternative to the Illizarov fixator. However, serial debridement along with freshening of bone edges due to persistent infection resulted in excessive shortening in one patient. To reduce the risk of knee stiffness, the patients were put on a CPM device in the early post-operative period. Despite this, some loss of knee flexion is inevitable. This loss can be partly attributed to quadriceps scarring due to infection and surgical trauma, but the fact that the fracture healed in all cases with subsidence of infection warrants further evaluation of this technique in such difficult situations. To the best of our knowledge, no other reports have described the use of this technique for femur fractures. Qiu et al. in their study reported the average union time of 21.2 weeks in proximal tibial fractures with compromised soft tissue ^[7]. The union time in our series with tibia fractures was shorter (average 19 weeks) despite the presence of local infection at the time of presentation. This could be because we dynamized the construct by gradually removing the screws and allowed the patients to weight bear while mobilizing as the union progressed. One patient (segmental femur fracture) sustained a refracture 4 weeks after the removal of the plate. This was probably a misjudgment on the part of the treating doctor, as there was inadequate callus on the medial side. There were no intraoperative or early post-operative complications. As compared to other studies, the incidence of screw track infection, as evidenced by pain, redness, and discharge around the screw, was higher in our study ^[17,18,19]. This may be due to the presence of preexisting infection in our series. The infection rate could have been lower with the use of a titanium plate screw construct ^[8,12]. None of these infections needed screw removal before the stipulated time and subsided with short-course antibiotic therapy.

Limitations of the study

We acknowledge some limitations of our study. The number of cases is small, and there was no control group. Although none of the cases needed revision of fixation, we did not do a cost analysis in this study, and therefore, no claim should ideally be made regarding the cost-effectiveness of locking plate external fixators as compared to other treatment methods. The drawback of locking plates over the limb reconstruction system or the Illizarov is that shortening cannot be addressed. Finally, the locking plates are not designed to be used as an external fixator, and with the limited quality evidence available, a comparison with established methods might not be appropriate.

Consistent, good radiological and clinical outcomes can be achieved using LCP external fixators a definitive fixation modality in selected cases of open lower limb fracture complicated with infection. The procedure is well tolerated by patients and provides adequate stability until bone union. There were relatively low overall costs because there was no need for a second operation to remove the plate, and the old plates can be reused. However, the large-scale prospective clinical study is warranted to verify our results. The present study describes a useful alternative for the treatment of these challenging cases of infected lower limb fractures and the basis for future research.

Locking plate external fixators offer a practical, cost-effective, and stable alternative in managing infected, extra-articular long bone fractures without bone loss. With proper patient selection and technique, this method can lead to favorable outcomes even in complex cases.