1 Introduction

Tibia being the most common fractured long bone¹ with recorded incidence of 17–21 per 100000 population, represents 2% of all fracture and 36.7% of all long bone fractures in adults.² Epidemiological studies have shown that open fracture comprises 23.5% of all tibial shaft fracture.³ The common causes of fracture are road traffic accident(62.2%), falls(18.7%), sports(7.4%) and direct blows(8.3%).¹ The lack of the muscular covering over anteromedial aspect of the tibia and poor blood supply predispose open tibial fractures to certain complications. They present with a 10–20 fold increased risk of developing infection than open fracture in any other anatomical areas⁴ and a nonunion rate as high as 28% has been reported in the literature.^5,6

Administration of broad spectrum IV antibiotics, meticulous wound debridement, operative stabilization of the skeletal injury and early soft tissue coverage of the open wound are all part of the therapeutic protocol.⁷ Treatment options for tibial fractures vary according to the type of fracture, age group, bone density, soft tissue status and associated complications.

Cast immobilization are associated high rate of malunion, upto 30%⁸ and nonunion in 28%.⁹ External Fixation have been widely used as they offer versatility, ease of application with minimum operative trauma, access to wound and usually no interference with free joint movement. However, they are associated with high rates of pin loosening, malunion and nonunion.^10,11 Reamed intramedullary are not frequently advised in open fractures, especially in Gustilo type III fractures due to damage to endosteal blood supply during the reaming process.^12,13 The use of unreamed intramedullary nailing has been associated with acceptable infection rates due to less interference with endosteal circulation, but a high rate of hardware failure has been reported in several studies.^13–15 The use of plates and screws has been discouraged by many authors due to potential damage to the periosteal blood supply during soft tissue stripping and increased risk of septic complications.¹⁶

The use of secondary intramedullary nailing after initial temporary external fixation have been advocated. Seconadary intramedullary nailing provides advantage of early weight bearing and enhances union as well as functional rehabilitation. But it requires another surgical procedure and a longer period of hospitalization which increases economic burden to the patient. Often the question on best time to convert external fixation to an intramedullary nailing remains unanswered.^17,18 Also, a high incidence of infection had been noted secondary to delayed intramedullary nailing.^12,19,20 Various randomized study reported no significant difference in infection rate or time to union when comparing external fixation versus unreamed intramedullary nailing.^21,22. Wiss and Stetson ²³ has contraindicated use of reamed intramedullary nailing in management of open tibia fracture due to associated high infection rate of 24%.²³

In the recent years, External fixation has gained more popularity as primary and definitive management of compound tibia fracture, so in this study we compare conventional AO unilateral external fixator and Limb reconstruction system(LRS) to evaluate functional and radiological outcome in patients with compound tibia diaphyseal fracture.

2 Methods

A prospective study was conducted in department of orthopedic surgery at Grant Govt. medical college and Sir J.J. Group of hospitals from 2014 to 2016. All patients attending the orthopedic department with compound tibial diaphyseal fractures who met the inclusion criteria were counseled regarding the disease and the study, those willingly consenting to participate in the study were selected. Informed and written consent was obtained from all patients with consent form approved by the Institutional ethical committee.

A total of 40 subjects were consecutively recruited for the study and grouped into Group I and Group II with 20 patients in each group. Age, gender and the incidence of high energy injuries were distributed evenly in the two groups. Group I(n = 20) patients were treated conventional AO external fixator and Group II(n = 20) patients were treated with Limb reconstruction surgery.

3 Results

The demographic characteristics of both Groups are shown as in Table 1.

In our study bony outcome by ASAMI score shows 6 (30%) patients had Excellent, 5 (25%) patients had Good and 9 (45%) had Poor bony outcome from Group I. In group II, 12 (60%) patients had Excellent, 4 (20%) patients had Good, 2 (10%) patients had Fair, and 2 (10%) had Poor bony outcome (Table 6).

In our study functional outcome by ASAMI score shows 3 (15%) patients had Excellent, 8 (40%) patients had Good, 5 (25%) patients had Fair, 3 (15%) had Poor bony outcome from Group I. In group II, 9 (45%) patients had Excellent, 7 (35%) patients had Good, 2 (10%) patients had Fair, and 2 (10%) had Poor bony outcome (Table 7).

4 Discussion

In our study, maximum cases were found in age group of 18–29 years i.e. 16 cases (40%) with mean age of 35.55 years which is comparable to Piwani et al²⁴ and Beltsios et al²⁵ where mean age were 34.75 years and 36 years respectively. There were 31 (77.5%) male and 9 (22.5%) female patients in our study which is comparable to the findings of Pal et al²⁶ and Memon et al²⁷ where maximum cases were male(80%). We had 29 patients who had sustained Road Traffic Accident (72.5%), and 11 (27.5%) patients fall from height, it is comparable with study of Piwani et al²⁴ and Beltsios et al²⁵ where mode of injury was found to be road traffic accident in 76.66% and 76.42% cases respectively.

In our study, 20% cases were type I, 15% were group II, 20% were group IIIA and 45% cases were grouped into type IIIB Gustilo-Anderson classification (Table 2). It is comparable with Piwani et al²⁴ and Iqbal et al study where maximum patients had type III B Gustilo Anderson type of compound tibial diphyseal fractures as compared to study by Tekan et al²⁹ and Neto et al³⁰ where maximum patients were of type IIIA (Table 4).

The time elapsed between injury and surgery at the hospital varied from 4 to 72 h in group I and 4–48 h in group II. Majority of patients 25 (62.5%) operated within 12 h (Table 3). Delay in surgery was due to the excessive time taken in transportation of patient from rural location to a tertiary care hospital and associated life threatening conditions which does not allow to intervene early for management of compound fractures. The timing of initial surgical intervention has wide variance within the literature. Historically, the 6-h rule has been employed as the time limit within which an open fracture should be taken to the operating room for initial debridement. Many factors influence this parameter including the operating room availability, surgeon availability, and the patient's physiologic status. Harley et al³¹ found no increase in infection rate and non-union rate, when debridement took place up to 13 h after the injury. The study also concluded that the strongest predictor for deep-seated infection was the grade of the fracture and not the time to debridement. Patzakis and Wilkins³² further confirmed, that the greatest determining factor was the timing of antibiotics and not the delay of debridement for more than 12 h. Naique et al³³ compared debridement of compound fractures within 6 h and between 6 and 24 h and excluded any difference in infection rates. Lastly, an extensive literature review by Crowley et al³⁴ investigating the time to debridement, showed that the 6 h rule needs to be re-evaluated (Figs. 1–8).

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Fig. 1 Larisa FAP and Lateral images at 2 weeks post operatively showing fixator loosening with lose of fracture reductionorea.

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Fig. 2 Immediate post operative AP and lateral images of Xray showing LRS fixator with acute locking at fracture site.

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Fig. 3 AP and lateral images at 20 weeks showing good fracture healing.

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Fig. 4 AP and lateral images at 22 weeks after removal of LRS showing acceptable bony alignment with adequate union.

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Fig. 5 clinical images after removal of LRS fixator showing good functional outcome.

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Fig. 6 Immediate post operative anteroposterior and lateral view.

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Fig. 7 Post operative anteroposterior and lateral view at 12 weeks.

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Fig. 8 Post operative anteroposterior and lateral view at 18 weeks showing bony union with acceptable alignment.

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In our study, Bone union time in group I was 23.65 ± 4.95 weeks and group II was 20.22 ± 5.22 weeks after injury. For Group I, results are comparable to Piwani et al²⁴ study, Khan et al³⁵ study, Beltisios et al²⁵ study where AO monolateral external fixator was used as definitive method of treatment with mean bony union time range 26 weeks, 25.6 weeks and 25 weeks respectively. For Group II, results are comparable to study by Ajmera et al³⁶, Olson⁶ where Limb reconstruction system was used as definitive mode of treatment with mean bony union time of 24 weeks and 22 weeks respectively.In comparison of both groups, LRS group has earlier union by average 3 weeks of duration.

Pin tract infection was seen in 8 (40%) patients in group I and 5(25%) patients in group II. Due to the more stability provided by tapering schanz pins in LRS, incidences of pin loosening (15%) and pin breakage (0%) are much lesser as compared to AO fixator where pin loosening was found in 40% and pin breakage in 10% cases. As the patients of group II where allowed to weight bear early due to strong fixation, incidence of joint stiffness (20%) was lesser as compared to group I with incidence of joint stiffness of (50%) .Due to increased pin site complications, premature fixator removal incidence was higher in group I which leads to higher cases of nonunion(45%) and need of secondary procedures (80%) as compared to group II where union rate was 100% and secondary procedures like corticotomy and distraction can be carried out in same system which aids cost benefits to patient.

Schanz screw design of Limb reconstruction system is such that it provides more stability to fixator. The use of 6 mm tapering narrow pitch screw increases pin-bone interference and pull out strength.³⁹ This large diameter pins have higher resistance to bending and it reduces stresses at the bone-pin interface⁴⁰ of fixator system and ensures that no flexion of screw occurs at the screw-cortex interface under normal functional loads.⁴¹ This absence of screw flexion minimize the likelihood of osteolysis and subsequent osteitis at these sites. This explains low incidence of pin tract infection and pin loosening.

In our study, malunion of >10′ was found in 06(30%) cases in group I as compared to 03(15%) cases in group II. The higher incidence of malunion with AO external fixator is comparable to study done by Dunbar et al⁴³ which showed malunion of 31% (Table 5).

AO monolateral frame being less stable than LRS, results in cantilever bending delivering asymmetric compression to the fracture site which promotes malunion and delayed union.⁴² The sliding clamp of LRS allows insertion of 3 schanz screws which can be locked and thus provides more stability. In addition to that, the swiveling clamps allows correction of malalignment of fracture ends without disturbing the screw position. In case of more proximal or distal 1/3rd fracture with short segment on one side, the use of T clamp allows more secure fixation of short segment and prevents any malalignment. Milnar et al⁴⁴ showed that tibial malunion are associated with increase incidence of osteoarthritis of knee and ankle joint.

Bony and functional outcome was assessed by ASAMI score. In our study, bony outcome in 6 (30%) patients had Excellent, 5 (25%) patients had Good and 9 (45%) had Poor bony outcome from Group I. In group II, 12 (60%) patients had Excellent, 4 (20%) patients had Good, 2 (10%) patients had Fair, and 2 (10%) had Poor bony outcome. Functional outcome in group I, 3 (15%) patients had Excellent, 8 (40%) patients had Good, 5 (25%) patients had Fair, 4 (20%) had Poor functional outcome. In group II, 9 (45%) patients had Excellent, 7 (35%) patients had Good, 2 (10%) patients had Fair, and 2 (10%) had Poor functional outcome.

Results of ASAMI score of group II was comparable to study by Ajmera et al³⁶, Patil et al³⁷ and Pal et al²⁶ where they found excellent results in 76%,67% and 68.75% respectively; good results in 12%, 25% and 18.75% respectively; fair result in 4%, 4% and 10% respectively; poor results in 8%, 4% and 2.5% respectively. Functional results was also satisfactory in 80% cases which is comparable to functional outcome by Pal et al²⁶ (75%) and Lakhani et al³⁸ (75%).

5 Conclusion

LRS (Limb reconstruction system) is very versatile tool as primary and definitive management of compound tibia diaphyseal fracture due to its ease of application, strong fixation, early weight bearing and high chance of bony union.

Conflict of interest

None.