Does 4 column classification of upper tibia fracture gives you better idea of fixation and impact on clinical outcome-analysis of 50 cases?

Introduction

Proximal tibia fractures are relatively common lower limb fractures and account for 1% of the total fractures^[1] with an estimated annual incidence of 10 per 100,000 people. While these fractures are more common in men overall elderly females are more prone to experiencing them. Most proximal tibia fractures occur between ages 40 and 60 in both genders.^[2]

In men, high-energy events like motor vehicle accidents are the primary cause of proximal tibial fractures. On the other hand, women often sustain these fractures through low-energy incidents such as falls during walking or cycling.^[2] Low-energy injuries typically lead to one-sided depression-type fractures, while high-energy incidents can result in more complex comminuted fractures with significant damage to bone, soft tissues, and nerves.^[3]

Fractures involving the proximal tibia can occur from various forces, including medial, lateral, or axial impacts. Medially directed forces, like a valgus forces are associated with classic "bumper fractures" seen in motor vehicle versus pedestrian accidents.^[4] More complex mechanisms involve combination of axial, varus, or valgus forces. In many cases, both shearing and compressive forces act on the underlying tibial plateau through the femoral condyle, either medially or laterally.^[5] Classification of proximal tibia fractures as per mechanism of injury has been provided below. ([Table 1])

Over the years management protocols of proximal tibia fractures have undergone significant changes but the main goal remains the same i.e. to maintain articular congruity, mechanical axis and joint stability.

Recent advances in the field of radiology with 3d computed tomography scans and MRI have helped to better classify the complex fracture patterns and associated soft tissue injury and also decide the plan of treatment and surgical approach to be taken.

Following paper documents, a case series of 50 cases managed as per classification and functional outcomes obtained in the form of knee society score.

Management of proximal tibia fractures

Classification

Classification system of proximal tibia has changed significantly over the years since the advent of modern radiological investigations. Below are the classification systems commonly used.

Schatzker et al.^[5]

The Ao/ Ota classification

Moore classification

Tscherne et al. ^[6]

Three-column concept of Luo and co-workers,^[7] later modified by Hoekstra et al^[8] ([Figure 1])

The 10- segment concept of Krause et al^[9] ([Figure 2])

Treatment options

Various treatment options available as per fracture patterns are listed below

Conservative treatment

Arthroscopic assited reduction and internal fixation(fracturoscopy)

Closed reduction and percutaneous fixation

Definative treatment with external fixation

Open reduction internal fixation

A pictographic representation of the management of the different case scenarios encountered has been listed below.

Materials and Methods

Results

Mean age of population sustaining proximal tibia fracture among males was 43.90 y and females was 48.71y with 86% predilection for male and 14% for female. Involvement of right tibia was 50% in comparison to left tibia which was 46%, while 4% patients had involvement of both limbs. Distribution of proximal tibia fracture; zero column -7.69%, one column- 55.77%, two column-21.15%, three column-15.38% ([Table 3]). Average knee society score(knee score, function score) at 9 months; zero column-94.25;90, one column-92.10;82.75, two column-86.63;77.28, three column-77.63;68.13. ([Table 4])

Average time for union in weeks was around 12 weeks for 21 patients and 12 to 24 weeks for 29 patients. ([Table 5])

Single incident of superficial infection was encountered managed with debridement and parenteral antibiotics. Single incident of deep infection was encountered managed with implant removal, debridement and parenteral antibiotics. Single incident of common peroneal nerve palsy was encountered repaired with extended Lobenhoffer approach.([Table 6])

Discussion

Proximal tibia fractures are usually a result of high velocity trauma i.e. road traffic accident and therefore seen mostly among young adults.^[11] In our study mean age was 46.3 years with males being predominantly affected.

Taking into consideration the associated soft tissue before planning the management of these fractures is of utmost importance. Staged management should be done as per literature with external fixator followed by definitive fixation as it provides time for the soft tissue to recover and improves the overall output of the surgery by decreasing chances of infection.^[12], ^[13] In our study, staged management was done by giving elevation on Bohler Braun splint and Mgso4 dressing or external fixator application considering the wound and skin condition of the patient. Skin over the proposed incision site was observed for wrinkles and the decision to proceed with surgery was made. Mean interval between injury and surgery was 7.2 days. Previous studies have reported a mean time to surgery of 9.2 days^[14] and 8.5 to 9 days.^[15]

The four-column classification is a recent development in managing complex intra-articular tibial plateau fractures, particularly beneficial for multiplanar fractures involving the posterior column. Posterior column fractures often result from valgus-varus stress shear, typically seen in a partially to completely flexed knee when the femoral condyles impact the posterior half of the tibial plateau. This specific fracture pattern is challenging to visualize on plain radiographs alone, leading to potential oversight in diagnosis.

Despite its prevalence in complex tibial fractures, this injury pattern lacks recognition in existing classification systems like AO/OTA or Schatzker. Compression in the lateral posterior condyle and splitting in the medial posterior condyle are common features of these fractures. It is therefore very important to study the exact configuration of the medial column in complex proximal tibia fractures through axial CT cuts to define whether the fracture line is in coronal i.e. posteromedial fragment or sagittal plane. Molenaars et al. found posteromedial fragment to be prevalent in 81% of type V and 95 % of type VI fractures in a CT based morphological study.^[16] Other studies have also found the presence of posteromedial fragment in 59%^[17] and 74%^[18] of bicondylar fractures. In our study prevalence of posteromedial fragment was 62.5% among cases of bicondylar fractures making it of immense importance to address the fragment separately as failure to do so might result in varus collapse and articular incongruity. Previously it was believed that a laterally placed locking plate would effectively buttress the medial fragment however it was found to be false in various clinical studies.^[15]

Utilizing computed tomography with 3d reconstruction enhances recognition of proximal tibial fracture fragments, aids in column classification, and facilitates surgical planning. For bicondylar and complex patterns, combined anterolateral and posteromedial approaches offer biomechanical and clinical advantages. The most intricate cases involve three-column fractures, requiring a combination of a reversed l-shaped posterior approach and anterolateral approach for optimal fixation. This comprehensive approach ensures better outcomes in challenging tibial plateau fractures.

The conventional anterolateral approach is typically employed for simple tibial plateau fractures, specifically corresponding to the exclusive lateral column, as seen in Schatzker type i, ii, and iii fractures. However, for complex patterns resulting from a ramified fracture line, a combined approach becomes necessary. Achieving adequate reduction and stabilization in posterior column fractures proves challenging with traditional techniques, prompting the use of modified posterior approaches tailored to different fracture patterns.

Various approaches, such as the modified posterolateral approach for posterolateral shearing fractures and the inverted l-shaped posterior approach for posterolateral fractures, have been advocated by different authors. However, these approaches may encounter challenges like exposure difficulties or secondary loss of anatomic reduction. Additional techniques, like partial or total excision of the fibular head, may aid in reduction and fixation of the posterior and lateral columns but come with potential drawbacks, such as compromising normal lateral knee stability.

The choice of approach is crucial, and in practice, a combination of anterolateral and posteromedial approaches is often used for comprehensive management. The surgical approaches used in our study, with respect to fracture morphology has been stated in table 2. However, intraoperative considerations, such as neurovascular injury, surgical exposure challenges, and the need for altering patient and limb positioning, must be carefully navigated during posterior column stabilization for complex fractures.

Chen et al. Advocated the use of screws, reconstruction plates, or t-shaped plates based on fracture morphology, while Zeng et al. recommended posterior t-shaped anti-glide plates for split fractures, providing improved biomechanical stability. The application of newer anatomical locking plates for the posterior column proves effective in preventing bony collapse and secondary loss of reduction. The three-column concept serves as a valuable tool for diagnosing and meticulously planning pre-operatively in multiplanar intra-articular tibial plateau fractures, especially those involving the posterior column.

In our approach, we utilized column-based anatomical locking plates for the medial and lateral columns. The stabilization of the posterior column involved the use of various plates such as recon plates, distal radius plates, small fragment plates, and screws, tailored to the complexity of the fracture.

The rate of infection in our study was significantly low due to stringent aseptic precautions and adequate assessment of soft tissue injury.

Secondary loss of reduction- In our study, there were no instances of secondary loss of reduction in the form of medial collapse measured with medial proximal tibial angle (≥5 degrees). Table 7 compares the incidence of secondary loss of reduction during healing as reported in literature. Before 3 column classification little weightage was given to the idea of loss of reduction and varus collapse in bicondylar fractures treated with single lateral plate in comparison to dual plating. A study conducted by Weaver MJ in 2011 evaluated relationship between fracture geometry, fixation construct and secondary loss of reduction. It was found that lateral construct alone does well only in cases of bicondylar tibial plateau fractures with sagittal fracture line. While in cases with coronal split lateral construct alone shows higher incidence of secondary loss of reduction. Our study also supports the above stated statement. Therefore, 3 d CT scans are indicated to delineate exact fracture geometry as plain radiographs provide limited information.

In our study, through our column-based operative management and early rehabilitation, we achieved average knee score of 87.65 and function score of 79.54 as per knee society score which were comparable to study by Nikolaou et al.

Conclusion

Recent computed tomography-based classification is very useful in understanding fracture topography, preoperative planning, fixation technique and deciding most suited surgical approach for proximal tibia fractures to achieve a smooth articular surface, mechanical axis and joint stability. Certain fracture fragments which could be missed on radiographs are taken into consideration and fixed with fragment specific approach which in turn, helps in early rehabilitation resulting in good functional and radiological outcome, reduced instances of secondary loss of reduction. One thing that has to be taken into consideration is the soft tissue condition as using more hardware increases the chances of infection and wound dehiscence, though it can be easily avoided by following staged fixation. Still, a long-term study with large study group is needed to confirm the usefulness of the same.

Source of Funding

None.

Conflict of Interest

None.