A Review of Tibial Shaft Fracture Fixation Methods

Abstract

Tibial shaft fractures are a commonly seen injury in orthopedic trauma patients. Fractures commonly occur following high energy mechanisms, such as motor vehicle collisions. There are multiple ways to stabilize tibial shaft fractures. Knowledge of the indications, contraindications, techniques, and complications associated with each technique allows the orthopedic surgeon to make the appropriate decision for each patient by providing both fracture and patient characteristics. This review discusses the indications, techniques, outcomes, and complications associated with intramedullary nailing, minimally invasive percutaneous plate osteosynthesis, and external fixation of tibial shaft fractures.

1. Introduction

Tibial shaft fractures represent approximately 37% of all long bone fractures in adults, with the highest incidence in males from ages 10 to 20 years old and an overall incidence of 17–21 per 100,000 population [1,2]. Fractures can occur following high energy or low energy mechanisms and are commonly a result of motor vehicle collisions, falls, or sport-related injuries [1,3]. The limited soft tissue coverage and subcutaneous location of the tibial shaft largely account for the approximately 24% incidence of open diaphyseal fractures [4,5]. High-energy open tibial shaft fractures are devastating and associated with severe bone and soft-tissue injury, thereby greatly increasing the risk of infection, nonunion, and wound complications [5]. Appropriate treatment decisions for these fracture patterns are multifactorial, accounting for specific patient factors, fracture characteristics, and concomitant injuries. Definitive surgical treatment options include intramedullary nailing (IMN), plate fixation, or an external fixator device. Recently, interest in minimally invasive percutaneous plate osteosynthesis (MIPPO) has outpaced traditional maximally invasive plating options. Each option has associated benefits as well as technical challenges.

Here, we review the indications, outcomes, techniques, and complications for these surgical treatment options with consideration of patient and injury characteristics for the fixation of tibial shaft fractures.

2. Intramedullary Nail

2.1. Indications

Intramedullary nailing is a widely used technique and remains the treatment of choice for unstable and displaced tibial shaft fractures [6]. This method involves the insertion of a metal rod into the medulla of the tibia, with the rod held in place by screws [7]. The goal of intramedullary nailing is to offer biomechanical stabilization and act as a load-sharing device to ensure early postoperative mobilization and adequate restoration of length, alignment, and rotation of the tibia [6]. Initially, most of the weight-bearing load passes through the nail, but, eventually, the load is gradually transferred to the bone as the fracture heals, allowing for early weight bearing [8,9]. This fixation method requires minimal surgical dissection, which allows for preservation of periosteal and soft tissue blood supply by minimizing tissue disruption surrounding the fracture site [10]. In addition to small incisions and minimal soft tissue disruption, this form of fracture stabilization allows for immediate weight-bearing, which has benefits that appeal to both providers and patients [11]. Both open and closed tibial shaft fractures are amenable to nailing.

2.2. Techniques and Outcomes

There are several different tibial nails on the market. Each implant consists of an antegrade intramedullary nail with proximal and distal interlocking screws. Historically, retrograde tibial nails have been used less frequently due to difficulty finding an entry point and lack of ideal implant design; however, a recent biomechanical study suggests that retrograde tibial nailing may be a promising new concept for distal tibial shaft fractures with or without an intra-articular extension [12]. Antegrade tibial nailing remain the current gold standard and can be performed through either a suprapatellar or an infrapatellar approach. Traditional infrapatellar nailing has been criticized for its increased risk of fracture displacement with required deep knee flexion and an incidence of post-operative anterior knee pain reported in the literature with prevalence from 10 to 80% [13]. The suprapatellar approach is currently more favorable as its semi-extended positioning facilitates fracture reduction. Studies have supported its superiority when compared to the infrapatellar approach, which can be attributed to reduced blood loss, improved post-operative pain, and better knee functional outcomes [13].

Regardless of the approach used, the ideal starting point for an antegrade tibial nail is just medial to the lateral tibial spine on the AP fluoroscopic image and anterior to the articular surface on the lateral image. Particularly, for proximal tibial shaft fractures, avoidance of a medial starting point is important to avoid potential valgus deformity [14]. Fracture reduction can be obtained with the use of bumps and percutaneous reduction clamps if needed [1,14]. Following fracture reduction, the guide wire can be placed through the start point to the level of the distal tibial physeal scar. If blocking (Poller) screws are indicated, the ideal time for placement is before reaming and nail placement [14]. Blocking screws are often used in proximal tibial shaft fractures where angular malalignment is most common. Blocking screws are used to effectively decrease the size of the proximal tibia and help control the path of the intramedullary nail. They are always placed in the concavity of the deformity, subsequently lateral and/or posterior to the nail in the proximal tibia to prevent the most common valgus and apex anterior deformity [14]. The final decision prior to nail placement is whether to ream the intramedullary canal. There are advantages to both; reamed nails offer a more rigid structure and earlier fracture union, whereas unreamed nails create less blood flow disruption to the cortex [15]. Current evidence suggests that reamed intramedullary nailing for closed tibial shaft fractures may lead to significantly lower risks of nonunion, screw failure, and hardware failure compared to unreamed nailing [15]. However, there is no current evidence to suggest that one offers superior outcomes when treating open tibial fractures and further research is required in this area [16].

2.3. Complications

The most commonly assessed complications of tibial nails are infection (which can be superficial or deep and may result in septic arthritis), non-union (typically defined as no signs of cortical healing after 6 months), and malunion (defined as angular or rotational malalignment of ±5 degrees). These complications are often influenced by the initial injury and whether it was open or closed, with closed fractures overall having lower rates of infection and better bone healing [4,17]. This is likely secondary to the trauma suffered by the surrounding soft tissues. A multicenter study conducted by Gaebler et al. with 467 cases found that a higher degree of soft tissue injury was correlated with a significantly higher rate of infection [4]. Despite this, a recent systematic review of 1850 patients with open fractures found that patients, overall, did quite well with an overall union rate of 91%. In addition, there was a delayed union rate of 22.4%, a malunion rate of 8.3%, a non-union rate of 9.7%, and an infection rate of 8.1% [18]. Protocols for the treatment of infection in the setting of nails are limited. In a seminal systematic review, Makridis et al. grouped treatment strategies into three stages [19]. Stage I was defined as early (within 2–6 weeks) superficial skin infections that only require antibiotic administration. If there was an underlying collection, then irrigation and debridement would be indicated. Stage II was defined as delayed infections (presenting 2 to 9 months post-operatively) that could be treated with antibiotics, debridement, and repeat reaming. If instability or poor bone healing was present, revision fixation with replacement of the nail with an antibiotic-impregnated nail was required. Finally, Stage III infections were classified as infected non-unions with established intramedullary osteomyelitis [19]. Treatment of these wounds required extensive debridement; revision to an alternative treatment modality, such as an Ilizarov frame; and bone loss restoration techniques (such as bone grafting or induced membrane technique) taking place after re-establishment of an aseptic environment.

While non-unions are often associated with infection, the first line treatment for aseptic non- or delayed-unions is dynamization of the nail, which is done by removing interlocking screws. According to biomechanical data, this increases micromotion and contact forces and improves the transmission of weight-bearing forces at the fracture site to induce callus formation [20]. Other benefits include low morbidity and low cost when compared to other more costly interventions [21]. In a recent systematic review, Hendrickx et al. found that the second most common cause for subsequent surgery was dynamization in 8.4% of cases (after symptomatic hardware removal) [22]. The major downside to dynamization is the risk of loss of reduction in unstable fracture patterns or in bone that has not had enough time to heal. Thus, the optimal timing for the dynamization of the nail is controversial. Most studies in the literature appear to perform dynamization anywhere from 8 to 30 weeks [23,24]. At this time, the relationship or association between timing and union success rates is unclear. As an alternative to dynamization, surgeons may decide to perform exchange nailing (removing the current nail, re-reaming the canal, and replacing it with a larger diameter nail) in the setting of nonunion. A retrospective, multicenter analysis by Litrena et. al. found that most surgeons favored exchange nailing in the setting of comminution and gapping [25].

It has been debated whether rates of anterior knee pain and iatrogenic damage to articular cartilage vary based on the use of suprapatellar versus infrapatellar techniques. Indeed, in a recent systematic review involving 8110 patients treated with an intramedullary nail, Hendrickx et al. found that the most frequent complication was anterior knee pain (23% of patients, n = 427 patients) [16]. Furthermore, in a recent systematic review and meta-analysis of 14 studies with 1447 patients, Bleeker et al. found no significant difference in rates of anterior knee pain between suprapatellar and infrapatellar (29% vs. 39%) techniques that was reflected in all the patient report outcome measures analyzed [26]. Additionally, there was no difference in infection, non-union, and subsequent surgeries.

IMN is a widely used technique for tibial shaft fractures as it requires minimal disruption to soft tissues and allows for effective fracture stabilization. Anterior knee pain and valgus or rotational misalignment are the major complications to be aware of.

3. Minimally Invasive Plating

3.1. Indications

Minimally invasive percutaneous plating osteosynthesis (MIPPO) for tibial shaft fractures is an increasingly popular treatment protocol for select patients. Typically indicated for patients with limited anterior and medial soft tissue coverage who are at high risk of wound complications with traditional plating, MIPPO can also be applied in polytrauma patients where intramedullary reaming is contraindicated due to increased pulmonary complications or when blocking screws, locking screws, or percutaneous reduction techniques are otherwise unfeasible [27,28,29]. Kati et al. also indicate MIPPO as an alternative for spiral oblique and spiral wedge tibial shaft fractures, theorizing that it provides better alignment and torsional stability [28]. Lastly, a posteromedial approach for diaphyseal tibial fractures using cadaveric specimens has shown that MIPPO can be used for patients with periprosthetic fractures, open physis, and inadequate access to intramedullary osteosynthesis [30,31]. The literature suggests that contraindications of MIPPO include severe open fractures with suboptimal soft tissue envelope of the medial ankle or distal ankle, severe comminution, and neurovascular compromise [27].

In contrast to IMN, which allows for immediate weight bearing, patients undergoing MIPPO are allowed to bear weight at 10–12 weeks postoperatively, depending on the radiographic signs of fracture healing and union [32,33,34].

3.2. Techniques and Outcomes

The MIPPO technique requires a 3 to 4 cm curved incision over the anterior border of the medial malleolus, with caution to preserve the saphenous vein and nerve [33]. A distal tibial plate is passed proximally through an extraperiosteal tunnel made with blunt dissection [32,33]. A C arm plate is then used to ensure the plate is adjusted to the contour of the bone and adequate reduction is performed, which is defined as varus–valgus angulation of <5°, anterior posterior angulation of <10°, and shortening of <15 mm [32]. Either locking cortical or cancellous screws are inserted with the remaining screws inserted by stab incisions, purchasing a minimum of six cortices on each side of the fracture [32,33]. Once the wound is irrigated by saline, closure can be achieved with absorbable braided material and monofilament subcuticular sutures [34]. Sterile dressing is subsequently applied, and a well-padded splint is given to ensure the ankle remains in the neutral position [32]. Postoperatively, full weight bearing is allowed after 10–12 weeks, depending on the radiographic signs of fracture healing and union [32,34].

When compared to IMN and external fixation, MIPPO techniques have shown either comparable functional outcomes [35,36,37] or slightly better results [27,38,39]. Advantages of this technique center on maintaining the integrity of the bone marrow and soft tissue envelope around the fracture, which leads to better healing of the wound. Possibly due in part to this preservation of the osteogenic fracture hematoma and periosteal blood supply, MIPPO techniques have shown to have a lower prevalence rate of nonunion (0.023) when compared to ORIF and IMN (0.081 and 0.054, respectively) [39,40,41].

Studies investigating MIPPO versus IMN outcomes demonstrate that tibial shaft fractures have functionally equal outcomes [35,42,43]. Notably, in this comparison, MIPPO shows virtually no prevalence of anterior knee pain; one study reports a prevalence of anterior knee pain in 29 out of 37 patients with IMN, but 0 of 36 with MIPPO reported pain [37]. While there is existing literature demonstrating better outcomes with MIPPO in tibial shaft fractures [41,44], they are balanced by equal studies showing preference for IMN [30,35]. There are no studies comparing MIPPO with external fixation alone; however, combined internal and external fixation (CIEF; two closed titanium elastic nails combined with an external fixator) had equivalent time to union, time to return to work, and American Orthopedic Foot and Ankle Society score [45].

One significant benefit of MIPPO is the decreased superficial and deep infection rate compared to both open plating and external fixation/CIEF [45], with equivalent rates of infection seen with IMN [42,43,46,47]. While MIPPO was initially thought to decrease operative time when compared to IMN and open plating, this has been brought into question with some studies [38,44] reporting a shorter operative index, while others report a statistically significant increase in time compared to IMN [36,37,40]. MIPPO takes considerably more time than external fixation alone as well as CIEF [37,45]. The surgeon’s familiarity with each technique as well as the complexity of the fracture also influence the overall surgical time.

3.3. Complications

The most encountered complication in patients who underwent MIPPO is the need for removal of hardware due to skin impingement (and less commonly due to cosmetic concerns). One study had 25 of 48 patients (52%) return for removal of hardware due to skin impingement, even with the use of smaller, less bulky plates [35]. The technique also shows a higher likelihood for recurvatum malunion vs IMN, although MIPPO has a lower risk of valgus or rotational malunions [41,42]. A final complication is increased ankle pain when compared to CIEF or IMN, with one study reporting 31.8% of patients who underwent MIPPO experiencing ankle pain significant enough to warrant removal of hardware compared to 9.1% of patients with CIEF. The pain subsequently resolved with the removal of hardware [45]. There is potential for entrapment of the superficial or deep peroneal nerves with the anterior tibial artery due to lack of visualization; however, cadaveric studies found that risk to be low with standard plate sizes [47,48].

Utilizing MIPPO techniques for tibial shaft fractures may lead to lower rates of nonunion and malunion, in addition to minimizing anterior knee pain while keeping time to union, infection risk, and operative index consistent with IMN. Increased ankle pain due to skin impingement is the most common complication, typically resolved with the removal of hardware.

4. External Fixation

4.1. Indications

External fixation of the tibial shaft can be used both for both initial stabilization in damage control orthopedics and as a definitive management option, depending on factors such as surgeon experience, fracture severity, fracture location, and the degree of soft-tissue injury [49,50]. External fixation is considered a safe and effective method of treating tibial shaft fractures in polytrauma patients with severe open and complex fractures and when internal fixation is impossible or inadvisable due to soft tissue compromise [49,50,51,52,53,54]. Poor soft tissue poses a threat to bone healing and limb salvageability secondary to infection risk; external fixation preserves the biomechanical environment necessary for fracture healing without damaging the blood supply or posing unnecessary risk to the soft tissues [49,51,55]. External fixation is the most common method of temporary management of open tibial shaft fractures [49,56]. Adequate reduction and union of fractures can be achieved by multiple frame constructs, including single level, multi-planar, and circular frames, via cylindrical axial micromotion through the fracture site to promote osteogenesis [57,58]. However, secondary fixation using intramedullary nailing is often required. This creates an economic, physical, and psychological burden on the patient and the healthcare system, which may make this strategy less ideal [59]. As a result, the external fixator device remains controversial in the literature, and its implementation likely depends on specific patient and injury factors.

4.2. Techniques and Outcomes

Milenkovic et al. evaluated the use of unilateral external fixation with convergent orientation of pins in 32 patients with segmental tibial shaft fractures [50]. They reported that external fixation as a definitive management approach for severe and open fractures should be performed 6–18 h from the time of injury with 2 pins in the proximal fragment, 2 pins in the distal fragment, and 1 or 2 pins in the middle fragment. Overall, 10–20% of patients were weight bearing immediately after surgery, and patients were given full-weight bearing status at 9–10 weeks after external fixator application. They reported better rates of union than previous studies of bi-dimensional planes of fixation. The authors further reported that a unilateral external fixator with convergent orientation of pins has a simpler application, allows for additional fracture reduction after index procedures without additional surgery, has a lower risk of neurovascular injury, is less cumbersome for patients to wear, and allows for plastic surgery intervention with frame in place when compared to an Ilizarov system. Although there are many benefits to unipolar frames, they are four to seven times weaker when stressed in the plane orthogonal to the pins [60].

Bayrak et al. performed a retrospective case control study of 76 patients with tibial shaft fractures secondary to gunshot wounds. They determined that the Ilizarov type external fixator had decreased hospitalization periods, time to full weight bearing, and time until union than the AO type unilateral external fixator [61]. In addition, in a retrospective cohort study of 93 patients with isolated Gustilo type III injuries stabilized with circular fixator or uniplanar external fixators, the new injury severity score and mean time for fracture healing were decreased in the circular fixator group, while the radiographic union score was increased in the circular frame group [56].

Multiple circular constructs, using a combination of wires and half pins, have been used with success [62]. These constructs provide high axial, bending, and rotational stiffness, resulting in axial micromotion which favors bone healing [62]. The hexapod external fixator is a multiplanar fixator consisting of two rings or partial rings connected by six telescopic struts at universal joints, allowing versatility of spatial deformity correction [51,63,64]. Adjusting the struts within six degrees of freedom, either acutely or gradually, allows for fracture reduction, correction of angulation, rotation, and translation, as well as leg lengthening [62]. In a study of 34 high-energy tibial shaft fractures treated with a hexapod external fixator, every patient achieved complete bone union and satisfactory alignment and were able to perform activities of daily living [51,55]. Advantages of the hexapod system include early trauma control, alignment versatility, and continuity of one device until union. In specific, 91% of patients achieved union, no infection, deformity < 7 degrees, and residual limb length discrepancy < 2.5 cm; they also reported no loss of reduction, malunions, or neurovascular injuries, and minimal residual radiographic translation angulation in the coronal and sagittal planes [51,55].

The Taylor spatial frame (TSF) is a multiplanar external hexapod frame with two rings or partial rings connected by six telescopic struts at universal joints; adjusting the position of one ring relative to the others allows six degrees of freedom [53,65,66]. Rotation, angulation, and translation deformities can be adjusted by manipulating the strut length after rings are allied independently. The TSF is applied on a traction table under image intensifier control; anatomic reduction of articular pieces is achieved with a limited ORIF with cancellous screws and washers [53]. Hydroxyapatite-coated pins are used to connect the bone to frames [53,65]. The TSF can also act as a temporary knee-spanning construct with additional tibial rings, which improves early weight bearing [66]. Once there is radiographic evidence of a bridging callus, dynamization of the frame confirms stable fracture union [65]. In a case series of 57 long bone fractures treated with TSF, 32 of which were tibial shafts, 89% of patients returned to pre-work activities [53]. A prospective radiographic study of functional outcomes of tibial shaft fractures demonstrated a return to a state of health no different from scores of the UK population as a whole in regard to mobility, self-care, return to activities, and anxiety [65]. It does come at a cost, however, as a TSF is twice as expensive as an Ilizarov frame [53,67]. On the contrary, the TSF allows continuity of the device, reduced risk of infection, early mobilization, restoration of the primary defect caused by bone loss, easy and accurate application, and increased versatility than a monolateral fixator [53,65,66].

4.3. Complications

External fixation is generally considered a safe, minimally invasive treatment option for the management of tibial shaft fractures. Nonetheless, traditional complications associated with external fixation include infection, nonunion, and malunion. Pin site infection rates have declined with advances in pin technology; however, infection rates remain significant [68]. Superficial and deep pin-tract infections are a primary concern, especially if the definitive fracture management includes an intramedullary nail. Deep infection rates following external fixation are equal to the rates observed after an intramedullary nail (reamed, minimally reamed, or unreamed); however, infection rates increase when implanting an intramedullary nail after an external fixation device has been in place for 2 weeks or more [69,70]. Pin care remains a controversial topic without a consensus agreement. A prospective study that compared pin care to no pin care demonstrated no difference in pin site granulation tissue, drainage, torsional stability, or osteolysis [71]. Therefore, it was concluded that routine pin care is not required if daily patient and frame hygiene is maintained. Although infection is the most commonly discussed complication, external fixation can also be associated with soft tissue breakdown, nonunion, and malunion. A network meta-analysis of 1279 patients concluded that external fixation was associated with increased rates of nonunion, malunion, and reoperations compared to intramedullary nailing of tibial shaft fractures [72]. Although external fixation is associated with infection, nonunion, and malunion, it is important to acknowledge that the incidence of these complications has declined secondary to advancements in biomaterials and knowledge of fracture healing, thus leading to improvements in external fixation pin design and frame constructs.

5. Conclusions

Tibial shaft fractures are a common injury frequently occurring in the younger male population and are associated with both low-energy sports-related trauma as well as high-energy motor vehicle accidents. Most tibial shaft fractures are treated surgically. However, a small percentage may be treated using closed reduction and casting followed by functional bracing [73]. Though closed reduction results in a higher rate of conversion to surgery, select patients and those in resource-limited regions with less severe injuries may benefit from this treatment [73]. Given the significant heterogeneity in injury presentation, IMN, MIPPO, and external fixation are the mainstay treatment options to achieve fracture fixation and healing. IMN has been the standard of care for the last two decades given its limited soft tissue exposure and mechanical properties that allow for immediate weightbearing post-operatively. IMN can be used to stabilize a variety of fracture patterns in both open and closed injuries, with reamed nailing resulting in lower complication rates for closed fractures than unreamed nailing. As an alternative, MIPPO retains bone marrow and periosteal blood supply, which in turn decreases infection and increases bone healing. Although external fixators remain a less popular definitive treatment option than IMN or plating, they are frequently used for temporary stabilization and are a viable treatment option in patients with systemic injury or severe open fracture. Finally, deep tissue infection can be avoided as long as the conversion to nailing occurs within the first 2 to 3 weeks after injury.