Biomechanical analysis of four different fixations for the posterolateral shearing tibial plateau fracture

Finite element analysis of a novel anatomical plate in posterolateral plateau fractures

Objective

This study aims to analyze the biomechanical characteristics of posterolateral plateau fractures fixed by a novel anatomical plate using finite element analysis.

Methods

A three-dimensional digital model of the full length of right tibiofibula was obtained by CT scanning. A posterolateral tibial plateau fracture model was then created. The acquired fracture model was assembled with 4 groups of internal fixations: Group A, novel anatomical plate; Group B, straight buttress plate; Group C, oblique T-shaped locking plate; Group D, two lag screws. Axial loads of 500, 1,000 and 1,500 N perpendicular to the horizontal plane were used to simulate the stress on the lateral plateau of a 65 kg person standing, walking and fast running.

Results

Vertical displacements of the posterolateral fragments in each of the four groups gradually increased under loads from 500 N to 1,500 N. The maximum displacement of the fracture fragment in four groups were all located on the lateral side of the proximal part, and the displacement gradually decreased from the proximal part to the distal end. The maximum displacement values under the axial load of 1,500 N was in the following order: novel anatomical plate (1.2365 mm) < oblique T-shaped locking plate (1.314 mm) < two lag screws (1.3747 mm) < straight buttress plate (1.3932 mm). As the axial load increased, the stress value of the different internal fixation models gradually increased. The stress behavior of the same internal fixation model under different loads was similar. The maximum stress value under the axial load of 1,500 N was in the following order: novel anatomical plate (114.63 MPa) < oblique T-shaped locking plate (277.17 MPa) < two lag screws (236.75 MPa) < straight buttress plate (136.2 MPa).

Conclusion

The patients with posterolateral plateau fractures fixed with a novel anatomical plate in standing, walking and fast running can achieve satisfactory biomechanical results, which lays the foundation for future applications. At the same time, clinical fracture types are often diverse and accompanied by damage to the soft tissue. Therefore, the ideal surgical approach and appropriate internal fixation must be selected based on the patient's injury condition.

Biomechanical analysis of tibial plateau posterolateral fracture fragment fixation and introduction of a lateral tibia plateau hook plate system

BACKGROUND

Fixing the posterolateral fragments of tibial plateau fractures has been challenging owing to potential neurovascular injuries and fibular head blocks. Several surgical approaches and fixation techniques have been reported, with distinct limitations. We propose a novel lateral tibia plateau hook plate system and compare its biomechanical stability with other fixation methods.

METHODS

Twenty-four synthetic tibia models were simulated to present posterolateral tibial plateau fractures. These models were randomly assigned to three groups. Group A models were fixed with the lateral tibia plateau hook plate system, Group B with variable-angle anterolateral locking compression plates, and Group C with direct posterior buttress plates. The models' biomechanical stability was evaluated using static (gradually increased axial compressive loads) and fatigue (cyclically loaded from 100 to 600 N for 2000 cycles each) tests.

RESULTS

Groups A and C models exhibited comparable axial stiffness, subsidence load, failure load, and displacement in the static test. Group A model exhibited higher subsidence and failure loads than Group B model. Groups A and C models exhibited comparable displacement at 100 N cyclic loading in the fatigue test. Group C model was more stable at higher loads. Group C model endured the highest subsidence cycle numbers, followed by Groups A and B models.

CONCLUSIONS

The lateral tibia plateau hook plate system provided similar static biomechanical stability as the direct posterior buttress plates and comparable dynamic stability under limited axial loading. This system is a potential posterolateral treatment choice owing to its convenience and safety, in treating tibia plateau fractures.

Newly designed plate for the treatment of posterolateral tibial plateau fractures: a finite element analysis

BACKGROUND

This study investigated the biomechanical properties of a new plate used for the treatment of posterolateral tibial plateau fractures using finite element analysis.

METHODS

The study groups were as follows: group PM, model of the new plate with posteromedial tibial plateau fracture; group PL, model of the new plate with posterolateral tibial plateau fracture; and group PC, model of the new plate with posterior tibial plateau fracture. We used two loading modes: uniform loading on the entire plateau, and loading on the posterior plateau. Data such as the displacement of the fracture and distribution of stress on the new plate and screws were recorded and analyzed.

RESULTS

When the whole plateau was loaded, the displacement of fractures in groups PM, PL, and PC were 0.273, 0.114, and 0.265 mm, respectively. The maximum stresses on the plates in groups PM, PL, and PC were 118.131 MPa, 44.191 MPa, and 115.433 MPa. The maximum stresses on the screws in Groups PM, PL, and PC were 166.731, 80.330, and 164.439 MPa, respectively. When the posterior tibial plateau was loaded, the displacement of the fractures in groups PM, PL, and PC was 0.410, 0.213, and 0.390 mm, respectively. The maximum stresses on the plates in groups PM, PL, and PC were 194.012 MPa, 72.806 MPa, and 185.535 MPa. The maximum stresses on the screws in Groups PM, PL, and PC were 278.265, 114.839, and 266.396 MPa, respectively.

CONCLUSION

The results of this study revealed that titanium plates have good fixation effects in all groups; therefore, the use of the new plate for posterolateral tibial plateau fractures appears to be safe and valid.

Effectiveness of bone grafting versus cannulated screw fixation in the treatment of posterolateral tibial plateau compression fractures with concomitant ACL injury: a comparative study

BACKGROUND

Posterolateral tibial plateau compression fractures (PTPCF) are one of the significant factors leading to knee instability and anterior cruciate ligament (ACL) reconstruction failure. The effectiveness of fixation for such cases without the use of metal implants remains inconclusive. The aim of this study is to investigate whether the fixation with isolated bone grafting is stable enough for the treatment of PTPCF with concomitant ACL injuries.

METHODS

This retrospective study analyzed patients treated for concomitant ACL injuries and PTPCF in authors' institution. A total of 53 patients (21 males and 32 females) with an average age of 47.43 ± 14.71 years were included. Patient data were collected, including factors leading to injury, affected side, height, weight, and basic medical history. The posterior inclination angle and the lateral tibial plateau lateral inclination angle were measured to evaluate the fixation stability. Rasmussen functional score and HSS score were used to assess the knee functional recovery.

RESULTS

The bone grafting group achieved satisfactory levels of Rasmussen score (28.22 ± 0.85) and HSS knee joint function scores (95.57 ± 1.97). The cannulated screw fixation group had a Rasmussen knee joint function score of 28.70 ± 0.92 and a HSS knee joint function score of 96.07 ± 1.93. No statistically significant difference was found (P > 0.05). The cannulated screw fixation group had a mean posterior inclination angle reduction loss of 0.20° ± 1.11°, while the bone grafting group had a reduction loss of 0.18° ± 1.01°, with no statistically significant difference (P > 0.05). The cannulated screw fixation group had a lateral inclination angle reduction loss of 0.01° ± 0.37°, and the bone grafting group had a reduction loss of 0.03° ± 0.43°, with no statistically significant difference (P > 0.05).

CONCLUSION

The use of bone grafting for fixation of PTPCF with accompanying ACL injuries demonstrated no substantial disparities in knee joint function. In cases of simple PTPCF, filling and compacting the bone defect underneath the tibial plateau fracture fragment can yield satisfactory fixation, obviating the necessity for supplementary cannulate screw fixation.

Potential problem and solution of lateral plate postposition for the posterolateral tibial plateau fracture

BACKGROUND

There has been controversial for the treatment of the posterolateral tibial plateau fractures (PTPF). This study aimed to evaluate clinic outcomes of the lateral locking compression plate (LCP) postposition, analyze the feasibility of LCP postposition through anatomical measurement, and address the potential problems of LCP postposition through the biomechanical assessment.

METHODS

39 patients with PTPF undergoing LCP fixation between June 2019 and June 2022 were retrospectively evaluated. All cases were divided into two group: Group A (15 cases) employed plate transverse arm postpositioning with posterolateral (PL) fracture fixation using two raft screws, while Group B (24 cases) utilized non-postpositioning with fixation by a single raft screw. Surgical duration, intraoperative blood loss, the change of lateral tibial plateau angle (LTPA), lateral tibial plateau posterior slope angle (LPSA) and fracture collapse between immediate postoperative and last follow up, range of motion (ROM), HSS knee score, and Lysholm knee score were recorded. CT measurements of the fibular head superior space and LCP transverse arm were taken in 50 healthy adult knees to assess postposition feasibility. Finally, three fracture models were established using finite element analysis: Model A with plate postposition and PL split fracture fixed by two raft screws of transverse arm, Model B with plate non-postposition and PL split fracture fixed by one raft screw, and Model C with plate non-postposition and PL split fracture fixed by one raft screw and anterior-posterior tension screws. Loadings of 250N, 500N, and 750N were applied for the analysis of the displacement degree, von Mises stress distribution.

RESULTS

Results indicate comparable operative duration and intraoperative hemorrhage between groups. Complications were minimal in both groups. Group A demonstrated superior outcomes in terms of radiographic parameters, functional scores, and fracture collapse prevention. CT measurements revealed compatibility in 72% of healthy knees with the postpositioning technique. Finite element analysis indicated favorable biomechanical stability.

CONCLUSION

Not all patients with PTPF were applicable to the management of the plate postposition and two raft screws fixation, even though this technique exerted good biomechanical stability and achieved satisfactory clinic outcomes. When the PL fracture was fixed by only raft screw through LCP owing to various reasons, two anterior-posterior tension screws might be necessitated to maintain the fracture stability.

Biomechanics and finite element analysis comparing posterior T-plates with LCP for fixation of posterolateral tibial plate fractures

Objective: The treatment for posterolateral tibial plateau fractures (PTPF) have been subjects of controversy. We conducted a study to improve the fixation of PTPF through a lateral approach. Methods: We utilized 40 synthetic tibias and categorized the fracture models into five groups based on the locking compression plate (LCP) and T-distal radius plate (TPP) via various forms of fixation with screws through the posterolateral (PL) fracture fragments. I: Two-screw fixation using two locking screws (LPTL). Ⅱ: Two-screw fixation with both variable angle locking screws (LPTV). Ⅲ: One-screw fixation with one locking screw (LPOL). Ⅳ: One-screw fixation with one locking screw and two anteroposterior lag screws (LPOLTL). Ⅴ: a distal radius plate with three locking screws (TPP). Biomechanical tests were conducted to observe the axial compression displacement of the PL fracture fragments at force levels of 250 N, 500 N, and 750 N, as well as to determine the failure load and the axial stiffness for each respective group. Results: Under a 750 N load condition, the displacements within the five experimental groups exhibited the following trend: Ⅴ < Ⅱ < Ⅰ< Ⅳ < Ⅲ. However, there were no significant differences between Group V and Group II, Group I and Group IV (p > 0.05), and only Group Ⅲ demonstrated a displacement exceeding 3 mm. The failure load and the axial stiffness exhibited the same trend. Conversely, statistical significance was identified among the remaining group compared with Group Ⅲ (p < 0.05). Regarding the finite element analysis, the maximum displacements for the five models under the load of 750 N exhibited the following trend: Ⅴ < Ⅱ < Ⅰ< Ⅳ < Ⅲ. The following trends were observed in maximum von Mises stresses for these models under the load of 750 N: Ⅴ < Ⅱ < Ⅳ< Ⅰ < Ⅲ. Conclusion: It is crucial to address the inadequate mechanical strength associated with single screw fixation of LCP for fixing PL fractures in a clinical setting. The biomechanical strength of two-screw fixation surpasses that of single-screw fixation. Introducing variable-angle screws can further enhance the fixation range. Furthermore, the addition of two lag screws threaded from anterior to posterior can compensate the mechanical stability, when PL fracture is fixed with single screw in clinic.

Mechanical Properties of Synthetic Bones Made by Synbone: A Review

Biomechanical engineers and physicists commonly employ biological bone for biomechanics studies, since they are good representations of living bone. Yet, there are challenges to using biological bone, such as cost, degradation, disease, ethics, shipping, sourcing, storage, variability, etc. Therefore, the Synbone® company has developed a series of synthetic bones that have been used by biomechanical investigators to offset some drawbacks of biological bone. There have been a number of published biomechanical reports using these bone surrogates for dental, injury, orthopedic, and other applications. But, there is no prior review paper that has summarized the mechanical properties of these synthetic bones in order to understand their general performance or how well they represent biological bone. Thus, the goal of this article was to survey the English-language literature on the mechanical properties of these synthetic bones. Studies were included if they quantitatively (a) characterized previously unknown values for synthetic bone, (b) validated synthetic versus biological bone, and/or (c) optimized synthetic bone performance by varying geometric or material parameters. This review of data, pros, cons, and future work will hopefully assist biomechanical engineers and physicists that use these synthetic bones as they develop experimental testing regimes and computational models.

Biomechanics and finite element analysis of a novel plate designed for posterolateral tibial plateau fractures via the anterolateral approach

Surgical management of posterolateral tibial plateau (PLTP) fractures is challenging. One reason for this challenge is the lack of suitable internal fixation devices. Our aim was to introduce a novel plate via the anterolateral approach for managing PLTP fractures. The biomechanical testing and finite element analysis (FEA) were performed. PLTP fracture models were created using synthetic tibias (n = 10 within each group). These models were randomly assigned to three groups (groups A-C) and fixed with the lateral locking plate, the posterior buttress plate, and the novel plate, respectively. The vertical displacement of the posterolateral fragments was evaluated using biomechanical testing and FEA under axial loads of 250 N, 500 N, and 750 N. We also evaluated the stress distribution and maximum stress of each fracture model using FEA. Biomechanically, under the same loads of 250 N, 500 N, or 750 N, the vertical displacement was significantly different among the three fixation groups (p ≤ 0.001). FEA data indicated that the maximum displacement from group A to C was 3.58 mm, 3.23 mm, and 2.78 mm at 750 N, respectively. The maximum stress from group A to C was 220.88 MPa, 194.63 MPa, and 156.77 MPa in implants, and 62.02 MPa, 77.71 MPa, and 54.15 MPa in bones at 750 N, respectively. The general trends at 250 N and 500 N were consistent with those at 750 N. Based on our biomechanical and FEA results, the novel plate could be a good option for treating PLTP fractures. The novel plate showed stable and reliable features, indicating its suitability for further clinical application.

Biomechanical study of a new rim plate fixation strategy for two kinds of posterolateral depression patterns of tibial plateau fractures: a finite element analysis

PURPOSE

The biomechanical capacity of "Barrel Hoop Plate (BHP)" in the treatment of the posterolateral tibial plateau (PL) depression fractures remains unknown. In this study, two kinds of posterolateral tibial plateau depression models involving mild slope-type depression fracture (MSDF) and local sink hole-type depression fracture (LSDF) were created to test and compare the biomechanical capacities of BHP with the other two conventional fixations (Anterolateral Plate and Posterolateral Plate, ALP and PLP) by finite element analysis.

METHODS

The 3D models of three kinds of plate-screw systems and the two kinds of PL-depression models (MSDF and LSDF) were created. An axial force of 400N was applied from the distal femur to the tibial plateau. The maximal displacements of the posterolateral fractures (PLFs), the distribution on the PLFs articular surface and key points displacements were measured. Stresses in the fixation complex including the maximal Equivalent (von-Mises) Stress of implants, the max shear stress of PLFs and stiffness of the fixation were calculated.

RESULTS

The maximal displacement of MSDF was least in Group BHP. The maximal displacement of LSDF was least in Group ALP. In MSDF, BHP showed the best rim fix effect in MSDF, but unsatisfactory results in LSDF. In both MSDF and LSDF, the greatest max Equivalent Stress of the plate and the screw occurred in the PLP system. ALP and BHP showed a comparable stiffness in MSDF and ALP had the strongest stiffness in the fixation of LSDF.

CONCLUSIONS

In MSDF, the BHP has the best biomechanical capacity, especially in displacements of key points such as the PL rim, fracture line, and depression center. In LSDF, the ALP system shows the best biomechanical effect. Although the PLP has the best fixation effect on the posterior wall, it is not suitable for PL-depression fracture fixation.

Comparison of the intraarticular osteotomy and the "window" osteotomy in the treatment of tibial plateau fracture involving depressed posterolateral fragments

OBJECTIVES

The methods of reduction of depressed posterolateral fragments in tibial plateau fracture through anterolateral approaches remain controversial. This paper aimed to compare the intraarticular osteotomy technique and the "window" osteotomy technique for the reduction of depressed posterolateral fragments through anterolateral approach.

METHOD

From January 2015 to January 2022, we retrospectively reviewed the data on patients with tibial plateau fracture involving depressed posterolateral fragments treated with the intraarticular osteotomy or the "window" osteotomy. 40 patients underwent the intraarticular osteotomy were divided into group A, while 36 patients underwent the "window" osteotomy were divided into group B. The operative time, bone grafting volume, fracture healing time, complication, reduction quality and postoperative functional results were compared between the two groups.

RESULTS

The average follow-up duration was 16.6 ± 3.7 months. The average bone grafting volume for all patients in group B was essential larger than group A (p = 0.001). Compared to group B, patients in groups A had significantly shorter fracture healing time (p = 0.011). The depth of depressed articular surface, PSA and the radiographic evaluation at 2 days and 6 months after surgery in group A were significantly lower than group B (p<0.05). Based on the HSS knee-rating score, no significant difference in function results was found between the two groups (p>0.05). No significant difference was found in operation time and blood loss between the two groups (p>0.05).

CONCLUSION

The intraarticular osteotomy could obtain satisfactory clinical results in tibial plateau fracture involving posterolateral fragments.

[Treatment of posterolateral tibial plateau fractures with a novel lateral tibial plateau annular plate via fibular neck osteotomy approach]

Objective

To investigate the effectiveness of a novel lateral tibial plateau annular plate (hereinafter referred to as the novel plate) fixation via fibular neck osteotomy approach for posterolateral tibial plateau fractures.

Methods

Between January 2015 and December 2018, 22 patients with posterolateral tibial plateau fractures were treated. There were 10 males and 12 females with an average age of 39.0 years (range, 25-56 years). Seven fractures were caused by falls, 10 by traffic accidents, and 5 by falling from height. The time from injury to hospitalization ranged from 3 to 12 days, with an average of 7.0 days. All patients were closed fractures. According to Schatzker classification, the fractures were classified as type Ⅱ in 8 cases, type Ⅲ in 9 cases, type Ⅴ in 1 case, and type Ⅵ in 4 cases. The fractures were fixed with the novel plates after reduction via fibular neck osteotomy approach. The fracture reduction and healing were observed by X-ray film after operation. The range of motion of the knee joint was recorded and the function was evaluated by modified American Hospital for Special Surgery (HSS) score.

Results

All operations were completed successfully. The operation time was 60-95 minutes (mean, 77.6 minutes). The intraoperative blood loss was 100-520 mL (mean, 214.5 mL). There was 1 case of common peroneal nerve injury during operation and 2 cases of fat liquefaction of incision after operation. All patients were followed up 13-32 months (mean, 19.4 months). Postoperative X-ray films showed that the fracture reduction was good in 17 cases and moderate in 5 cases, and all fractures healed with a healing time of 10-18 weeks (mean, 13.0 weeks). At last follow-up, the range of motion of the knee joint ranged from 100° to 145° in flexion (mean, 125.5°) and from 0° to 4° in extension (mean, 1.2°). The modified HSS score was 82-95 (mean, 86.3). There was no complications such as plate deformation, screw fracture, fracture reduction loss, skin necrosis, and so on.

Conclusion

For posterolateral tibial plateau fractures, the novel plate fixation via fibular neck osteotomy approach has the advantages of clear intraoperative field, firm fracture fixation, and less postoperative complications, which is beneficial to the recovery of knee joint function.

Lateral locking plate plus antero-posterior lag screws techniques for the management of posterolateral tibial plateau fracture: preliminary clinical results and biomechanical study

INTRODUCTION

To date, there is no consensus on the optimal surgical strategy for the treatment of posterolateral tibial plateau fracture (PLF). This study introduced a novel, simple technique for treating PLF with a lateral locking plate plus antero-posterior lag screws (LPpLS).

METHODS

We conducted a retrospective case series of 42 patients (Female/Male 19/23) with PLF treated with LPpLS between 1 July 2016 and 30 June 2019. Several pre- and postoperative outcomes were recorded, including operative time, intraoperative blood loss, CT findings, HSS, and ROM. For biomechanical studies, seventy synthetic tibiae with a simulated posterolateral split fracture were divided into seven groups. The biomechanical evaluation included displacement measurement at axial compression and fatigue testing.

RESULTS

Forty-two eligible patients were followed up for an average of 18 months (range 14-21 months). Postoperative radiographs and CT showed good positioning of plates and screws, no fracture fragment loss, and normal articular surfaces in all 42 cases. The biomechanical study showed that the axial stiffness of LPpLS was in the same fashion as the posterior buttress plate and better than the other fixation methods (P < 0.05). Additionally, the LPpLS group had a smaller displacement of fracture fragments along the X-axis (medial to lateral direction) than the BP group (P < 0.01).

CONCLUSIONS

The LPpLS technique could implement good reconstruction of the PLF, showing satisfactory therapeutic effect. The biomechanical evaluation demonstrated that the LPpLS had better stability in three-dimensional directions for PLF than other fixation strategies.

Posterolateral Fractures of the Tibial Plateau Revisited: A Simplified Treatment Algorithm

High-energy fractures of the proximal tibia with extensive fragmentation of the posterolateral (PL) quadrant of the tibial plateau are challenging to manage. Herein, we present a review of the literature on the patterns and options of approach and fixation of the PL fragment of the tibial plateau to optimize the treatment of this specific injury pattern. We searched PubMed (1980-May 2020) to identify and summarize the most relevant articles evaluating both the morphology and treatment recommendations, including the choice of approach and fixation strategy, for the PL tibial plateau fracture. We found PL fragment can present in several patterns as a pure split, split depression, contained pure depression, and noncontained depression (rim crush), which are mostly determined by the position of the knee and the force magnitude applied during the course of the accident. Based on previous concepts described by Schatzker and Kfuri, we suggest a simplified treatment algorithm highlighting the two concepts (buttressing and containment) used for plating the PL tibial plateau fragments. Based on the available current evidence, we propose an algorithm for these two morphological types of PL tibial plateau fracture. Shear-type fractures need buttressing (the "rule of thumb"), whereas noncontained peripheral rim-type fractures need peripheral repair and containment. Contained pure depression fractures are not frequent and need percutaneous-assisted elevation and subchondral rafting, either controlled by fluoroscopy or arthroscopically. It is believed that such an approach would simplify their assessment and preoperative planning and would assist the clinicians to appreciate and manage more consistently these complex injuries.

Anterior Tibial Artery and Its Clinical Importance in the Posterolateral Approach to the Tibial Plateau: An Angiographic Study on 219 Lower Limbs

The anterior tibial artery (ATA) is the most critical anatomical structure at risk at the distal border of the posterolateral approach to the tibial plateau. This study aimed to use available lower extremity digital subtraction angiography (DSA) images to determine the distal safe limit of this approach by measuring the distance from the tibial joint line to the ATA where it pierces the interosseous membrane. Tibial plateau mediolateral width (TP-ML-W) and the perpendicular distances from the ATA to the tibial joint line and fibular head were measured on DSA images in 219 lower extremities. To normalize the distances according to the tibial dimensions, each distance was divided by the TP-ML-W, and a ratio was obtained. Popliteal artery branching pattern was categorized according to the classification proposed by Kim et al. Comparative analysis between right and left extremities, genders, and anatomical variations were performed. There were 102 male and 26 female subjects with a mean age of 60.7 ± 15.7 years (range, 17-92 years). Ninety-one subjects had bilateral lower extremity DSA; thus, a total of 219 extremities were analyzed. The TP-ML-W was wider in male (78.3 ± 7.0) than female (70.5 ± 7.3) subjects (p = 0.001). The ATA coursed through the interosseous membrane at 50.9 ± 6.9 mm (range, 37.4-70.2 mm) distal to the tibial plateau joint line, and it was 66.5 ± 7.2% of the TP-ML-W. The ATA coursed through the interosseous membrane at 36.5 ± 6.0 mm (range, 21.9-53.8 mm) distal to the fibular head, and it was 47.7 ± 6.6% of the TP-ML-W. All measured variables were similar between the regular branching pattern of the popliteal artery (type 1A) and other observed variations among male subjects. The safe length of dissection in the posterolateral approach is average 66.5% (range, 45.7-86.7%) of the TP-ML-W. This ratio is valid for both genders. The use of a ratio instead of a distance, which is subject to personal variations, seems to be more logical and practical for planning this surgery, but the wide range should still not be ignored.

Comparison Between Treatment of Bicondylar Tibial Plateau Fractures With or Without Posterolateral Fragments Using Posteromedial and Anterolateral Approaches

BACKGROUND

The best surgical approach for treating posterolateral fragments in tibial plateau fractures remains controversial. This study compared the radiological and functional outcomes of bicondylar tibial plateau fractures, with or without posterolateral fragments, treated using the same posteromedial and anterolateral approaches.

METHODS

Twenty-six patients with 27 bicondylar tibial plateau fractures were surgically treated between June 2006 and February 2020. The patients were divided into two groups: with posterolateral fragments (PL group) and without posterolateral fragments (non-PL group). All patients were treated with the combined posteromedial and anterolateral approach. Knee function was assessed using the Lysholm score and by measuring the range of motion (ROM). Fracture reduction was assessed using Rasmussen radiological scores.

RESULTS

Fifteen bicondylar fractures were classified in the PL group and 12 in the non-PL group. No significant difference was found in the ROM and Lysholm scores between the groups. No significant difference was noted in Rasmussen radiological scores between the groups.

CONCLUSION

Using the combined posteromedial and anterolateral approach, bicondylar tibial plateau fractures with posterolateral fragments achieved reasonable functional and radiological outcomes compared to those without a posterolateral fragment. This combined approach enabled an adequate visualization and reduction of posterolateral fragments. These standard approaches may be adequate for most bicondylar tibial plateau fractures with posterolateral fragments.

The Study of Biomechanics and Clinical Anatomy on a Novel Plate Designed for Posterolateral Tibial Plateau Fractures via Anterolateral Approach

There is no consensus about the optimal internal fixation selection for treatment of posterolateral tibial plateau fracture. This study described a novel plate through an anterolateral approach for posterolateral tibial plateau fractures (PTPFs). We evaluated the biomechanical performance of a novel plate and two conventional internal implants and investigated the anatomic feasibility of the novel plate. The fracture models were randomly assigned into six groups: Groups A–C were the model groups of posterolateral split fracture, fixed with the posterior buttress plate, the lateral locking plate, and the novel plate, respectively. Groups D–E were the model groups of posterolateral depression fracture, fixed with the posterior buttress plate, the lateral locking plate, and the novel plate, respectively. We evaluated the biomechanical performance of six model groups by the biomechanical testing and finite element analysis. Progressively increasing axial compressive loads were applied to each synthetic fracture model by using a customized indentor under 250–750 N loads. Meanwhile, we dissected 12 fresh frozen knee specimens and fixed them with the novel plate through the anterolateral approach. We recorded the adjacency of the novel plate to important anatomic structures. Biomechanical testing showed that the novel plate had the least displacement, followed by the posterior buttress plate, and the lateral plate had the most displacement in posterolateral split fracture. There was no significant difference in the displacement between the novel plate and the lateral plate at different loads in posterolateral depression fractures. And the posterior buttress plate showed the most displacement. In the finite element analysis, the maximum stress values of Groups A, B, and C were 383.76, 414.63, and 305.07 MPa under the load of 750 N, respectively. The maximum stress values of Groups D, E, and F were 474.28, 436.31, and 413.4 MPa under the load of 750 N, respectively. In the anatomic study, the placement of the novel plate had a low risk of damage to the important anatomic structures of knee posterolateral corner. The novel plate could be a great choice for the treatment of PTPFs due to better biomechanical performance and easy manipulation.

Dual split and dislocation----a variant of Schatzker type-I tibial plateau fracture: A case report

Schatzkter type-I tibial plateau fracture is a split fracture of the lateral tibial plateau in sagittal plane, consequent to valgus impaction caused by low velocity of trauma. However, a deep understanding of the different columns of the tibial plateau and patho-mechanisms of the injury led to the unmasking of atypical fractures around the tibial plateau. We have encountered 2 cases with unusual fracture pattern of the lateral tibial condyle caused by road traffic accidents. The fracture pattern and severity of injury deviate from the original description of Schatzker type 1; in view of dual plane split, there is rotation of the posterolateral column fragment along its sagittal plane plus grade-III medial collateral ligament injury. The patients were initially treated with knee spanning external fixator and after a latency of 5 days, definitive fracture specific fixation was done, combined with repair of grade-III medial collateral ligament injury. At the 6 months follow-up both the patients achieved satisfactory knee functions (knee society score case 1: 100 and case 2: 92) and returned to their jobs. The severity of fracture pattern and displacement as described should prompt for examination of associated ligament injury. Because of timely diagnosis, early and appropriate care promised an excellent function outcome even in such a severe nature of knee injury. To prompt the description of injury pattern we coined the name "dual split and dislocation" of lateral tibial plateau, as a complex injury variant of split fracture of lateral tibial plateau fracture.

Treatment of tibial plateau fractures involving the posterolateral column using the extended anterolateral approach

To summarize the surgical technique and clinical effects of the extended anterolateral approach for the treatment of Schatzker type II and Schatzker type V/VI involving the posterolateral column tibial plateau.From January 2015 through December 2018, 28 patients with tibial plateau fractures involving the posterolateral column were included in the study. Among them, 16 patients were Schatzker type II treated using an extended anterolateral approach with lateral tibial locking compression plate fixation. Twelve patients were Schatzker type V or VI treated using an extended anterolateral combined with a medial approach using lateral tibial locking compression plate plus medial locking compression plate fixation. All cases were followed up for 15 to 31 months, with an average follow-up of 22.5 ± 3.7 months. During the follow-up, the tibial plateau angle (TPA), lateral posterior angle (PA) and Rasmussen radiological criteria were used to evaluate the effect of fracture reduction and fixation; the Hospital for Special Knee Surgery score and the range of motion were used to evaluate knee function. Additionally, the Lachman and knee Valgus (Varus) stress tests were used to evaluate anteroposterior and lateral stability of the knee.All fractures healed. At the 12-month follow-up, the Schatzker type II group revealed a mean TPA of 86.38 ± 3.92°, a mean PA of 7.43 ± 2.68°, and a mean Rasmussen radiological score of 16.00 ± 2.06 points. The Schatzker type V/VI group showed a mean TPA of 84.91 ± 3.51°, a mean PA of 9.68 ± 4.01°, and a mean Rasmussen radiological score of 15.33 ± 2.99 points. During the 1-year follow-up, when the postoperative PA was re-measured, the TPA and Rasmussen score of the 2 groups did not change significantly (P > .05). At the last follow-up, the Schatzker type II group showed a knee flexion angle of 110° to 135° and a mean HHS score of 88.37 ± 10.01 points. The Schatzker type V/VI group revealed a knee flexion angle of 100° to 130° and a mean HHS score of 82.17 ± 10.76 points. Additionally, up to the last follow-up, the Lachman and knee Valgus (Varus) stress test results of the 2 groups were negative. No complications were found.The extended anterolateral approach is a good choice to treat tibial plateau fractures involving the posterolateral column.

The treatment of posterolateral tibial plateau fracture with a newly designed anatomical plate via the trans-supra-fibular head approach: preliminary outcomes

Background

There are no ideal plates or approaches for anatomical restoration and rigid fixation of posterolateral tibial plateau fractures. This study aimed to evaluate the short-term preliminary outcomes of our novel anatomical plate placed via the trans-supra-fibular approach to treat posterolateral tibial plateau fractures.

Methods

From May 2016 to May 2018, 23 consecutive patients with posterolateral tibial quadrant fractures underwent open reduction with internal fixation via the trans-supra-fibular-head approach with our newly developed plate. The tibial plateau-tibial shaft angle (TPTSA), lateral posterior tibial slope angle (LPSTA), step-off, and condylar widening were measured on radiological images pre-operatively, 3 days post-operatively, 3 months post-operatively, and at the final follow-up examination. The radiological Rasmussen score was calculated, and the Hospital for Special Surgery (HSS) knee score was assessed to evaluate the functional outcomes.

Results

The LTPSA, TPTSA, step-off, and condylar widening at 3 days post-operatively, 3 months post-operatively, and at the final follow-up were significantly different (p = 0.001) compared with those pre-operatively, as was the radiological Rasmussen score (p = 0.001). The HSS score at the final follow-up was 89.10 ± 5.94 (range, 78–98), which was significantly higher than that at the 3-month follow-up 84.36 ± 6.76 (range, 74–96); p = 0.001).

Conclusions

Our newly designed anatomical plate placed via the trans-supra-fibular approach can effectively treat posterolateral tibial plateau fractures. We noted minor trauma, stable fixation, and satisfactory clinical results.

A proposal of a new algorithm for decision-making approaches in open reduction and internal fixation of complex tibial plateau fractures - SOTA algorithm (Spanish Orthopaedic Trauma Association)

INTRODUCTION

The correct choice of surgical approaches in complex tibial plateau fractures is essential to achieve adequate reduction and fixation. Detailed fracture morphology and direction of columns displacement, that we have named the Main Deformity Direction (MDD), may aid in selecting the optimal surgical strategy. In this article we present a new algorithm based on MDD and column concepts. The aim of this study was to evaluate the outcomes of a group of tibial plateau fractures treated according to this algorithm. The secondary aim was to evaluate the incidence of the different MDD in our multicolumnar subgroup.

PATIENTS AND METHODS

Excluding isolated lateral one-column fractures, open fractures and patients not treated following this algorithm, 72 patients with tibial plateau fractures surgically treated with open reduction and internal fixation were collected retrospectively, from three trauma centers, from January 2015 to April 2019. Radiological assessment was performed to establish the columns involved and the MDD. Quality and maintenance of reduction and alignment, complications and functional outcomes were assessed.

RESULTS

Initial fracture analysis was performed in 72 patients (8 one-column, 35 two-column and 29 multicolumnar fractures). In the multicolumnar group, the posteromedial MDD was the most frequent pattern (17 of 29 patients). Four patients were excluded due to loss of follow-up, resulting 68 patients for final outcome analysis (7 one-column, 34 two-column and 27 multicolumnar). The average follow-up was 18 months (range: 6-52). Excellent/good outcomes were obtained in all one-column, 31 of 34 two-column and 25 of 27 multicolumnar fractures. Incomplete reduction was present in three patients. As complications, we had two loss of reduction, one conversion to knee arthroplasty, one nonunion and one deep infection. No patient presented neurological or vascular problems, knee instability or extension deficit.

CONCLUSION

Satisfactory results have been obtained following the principles of our algorithm. In addition to the anatomical involvement of columns and segments, we believe that identifying the Main Deformity Direction (MDD) provides useful information for decision-making, especially in multicolumnar fractures. The most frequent MDD in our multicolumnar subgroup was the posteromedial MDD, but more than one-third presented a different MDD, requiring different surgical strategies.

Solving the enigma of posterolateral tibial plateau fractures, the clue protocol

The study aim is to evaluate functional and radio- logical outcomes following a suggested protocol based on the four-column classification for management of posterolateral column tibial plateau fractures. A prospective cohort study was performed in level I academic center on 42 patients with mean age of 36 years (22-59). Eleven patients had isolated posterolateral column fractures whereas 31 patients had associated columns fractures. According to the suggested protocol, all cases of isolated posterolateral column fracture started treatment via arthroscopic evaluation of soft tissue injuries (menisci and liga- ments), arthroscopically assisted reduction and inter- nal fixation by rafting screws followed by ORIF if plating was needed. If associated with other columns fractures, columns were fixed sequentially in an anti-clockwise direction starting from anteromedial column. Average follow up was 26 months. Mean time to union was 16.3 (12-22) weeks. No radiological evidence of loss of coronal or sagittal alignment was detected at final follow up. Five patients had an average depression of 5 millimeters that did not need further intervention at this short-term follow up. Mean KOOS was 81 (72- 88). The average knee range of motion was (0° - 127°). One patient had temporary common peroneal nerve injury, one patient had deep infection and two had superficial wound infection. implementing the suggested protocol gives good to excellent radiological and functional results as regard posterolateral tibial plateau fracture. A larger study group with longer follow up is needed.

Treatment of Isolated Posterolateral Tibial Plateau Fracture with a Horizontal Belt Plate through the Anterolateral Supra-Fibular-Head Approach

The posterolateral tibial plateau fracture was not easy to be exposed and fixed with usual techniques. The aim of this study was to investigate the biomechanical stability and clinical outcome of the isolated posterolateral tibial plateau fracture fixed with a single horizontal belt plate through the anterolateral supra-fibular-head approach. Fracture models were created by 18 synthetic tibias and fixed with three different fixation modes. Each group was fixed and tested on the loading machine, and final vertical displacement of the fragment was detected and calculated. Clinically, a retrospective analysis of 12 cases of posterolateral tibial plateau fracture from January 2013 to December 2017 was performed. There were 8 males and 4 females, aged 33-72 years, with an average age of 49.6 years. Isolated posterolateral tibial plateau fractures were identified according to preoperative X-ray and computed tomography scan. Through the modified anterolateral supra-fibular-head approach, the fracture was reduced and fixed by a prebending T-shaped distal radius plate and rafting screws, with bone substitute grafting or autogenous iliac bone implantation. Patients were followed up to a minimum one year of time period, and the outcome was evaluated clinically and radiologically. The biomechanical study shows that horizontal belt plate fixation for the isolated PL tibial plateau fracture can provide sufficient stability, allowing early knee functional exercise and partial weight bearing. For clinical case series, the average operation time in this group was 73.3 ± 10.2 mins (range: 55-90), and the average duration of hospitalization was 9.1 ± 3.3 days (range: 5-16). Patients were followed up for 12-24 months with an average of 16.5 months, and all patients achieved radiological fracture union after an average of 13.7 weeks. At one year after operation, the average knee score of the Hospital for Special Surgery (HSS) scale was 93.2 ± 4.2 points(range: 90-98), the average score of SMFA was 21.1 ± 5.6 points (range: 14-31), and the average knee range of motion (ROM) was 121.48° ± 8.88° (range: 105°-135°). There were 8 cases that were very satisfied and 3 cases that were satisfied with the operation. For an isolated posterolateral tibial plateau fracture, the supra-fibular-head approach can fully expose the fracture site; the horizontal belt plate fixation of the fracture is stable and reliable to allow for early-stage knee rehabilitation, and the outcome of medium-term clinical follow-up was satisfactory.

Biomechanical analysis of "Barrel hoop plate" technique for the posterolateral fragments of tibial plateau fractures with different displacement tendency

OBJECTIVES

The purpose of our study is to evaluate the three-dimensional biomechanical properties of "Barrel Hoop plate" in two kinds of artificial posterolateral tibial plateau fracture fragment (PLF) by using of synthetic models, each of which has an initial amplifying displacement tendency.

MATERIAL AND METHODS

Thirty-six tibiae models were randomly assigned into two groups with different displacement tendencies: posterior displacement (PD) and lateral displacement (LD). Each model was then fixed with three patterns: Anterolateral plate (AP), Posterolateral plate (PP), and "Barrel Hoop plate" (BHP). Displacement in three axes of vertical, sagittal and horizontal axis was captured by Optotrak Certus motion analysis system. Bluehill 2 software was used for load control and data collection.

RESULTS

In Model-PD, when the load was over 1000 N, the posterior displacement of Group-PP and Group-BHP were less than Group-AP (P<0.01). The inferior displacement in the vertical axis of Group-PP was larger than both Group-AP and Group-BHP in all the loading set (P<0.01). In Model-LD, both of the lateral displacement in Group-AP and Group-BHP was less than that of Group-PP when the load was over 1000 N (P<0.01). The inferior displacement of Group-AP was less than that of Group-PP in the load of 1500 N (P<0.01). Both of the posterior displacement of Group-AP and Group-BHP was less than that of Group-PP when the loading was 1500 N (P<0.01). The stiffness of Group PP was less than that of Group AP (P<0.01).

CONCLUSIONS

The results demonstrated that the 2.7 mm "Barrel Hoop plate" had a greater capacity of anti-three-dimension axes displacement of PLF. The 3.5 mm Anterolateral plate had the advantage in anti-lateral displacement and anti-inferior displacement but was weak at anti-posterior displacement of PLF. The 2.7 mm Posterolateral plate was stronger in anti-posterior, however, weak in anti-inferior displacement capacity.

A Novel Method of the Treatment for Posterolateral Tibial Plateau Fractures

Reduction and fixation of posterolateral tibial plateau fracture via a posterolateral approach is challenging, and the posterolateral approach itself may injure the posterolateral ligament complex of the knee and can result in knee instability. We developed a new curved support plate (CSP) that can pass, via traditional anterolateral approach, through the superior tibiofibular interval and effectively support the posterolateral fragments. The purpose of our study was to determine the biomechanical reliability of the new plate and report the preliminary efficacy of the CSP for posterolateral tibial plateau fracture. In the biomechanical experiment, 40 synthetic tibias were used to create posterolateral shearing tibial fracture models, which were randomly assigned to groups A to D. Vertical displacement of the posterolateral fragments was measured under axial loads of 500 to 1,500 N. The new plate and 3.5-mm lateral locking plate exhibited similar control over fragment displacement. From June 2016 to August 2017, eight patients with posterolateral tibial plateau fracture underwent treatment with the CSP. Hospital for Special Surgery (HSS) knee score, knee flexion and extension ranges of motion, and complications were recorded to evaluate treatment effects. Eight patients (five men and three women, mean age 44 years [range, 23-66 years]) were enrolled in the study. Mean follow-up time was 13 months (range, 7-19 months). All patients achieved radiographic bone union by 3.3 months (range, 3-4 months) postoperatively. There were no complications of neurovascular injury, deep vein thrombosis, infection, and implant loosening throughout the follow-up period. At final follow-up, mean HSS score was 92.6 (88-96), with a mean knee flexion of 131.25 degrees (120-135 degrees) and a mean knee extension of 1 degree (0-5 degrees). Fixation of posterolateral tibial plateau fracture was easily and successfully achieved using our newly designed CSP, which may provide a new choice for posterolateral tibial plateau fractures.

Clinical results after surgical treatment of posterolateral tibial plateau fractures ("apple bite fracture") in combination with ACL injuries

PURPOSE

The anterior cruciate ligament (ACL)-tear is a common injury in orthopaedic trauma. Depending on the energy of impact fractures of the posterolateral tibial plateau are often associated. Different morphologic variants of posterolateral tibial plateau impaction fractures have been described in the setting of an ACL-tear. Up to now an algorithm of treatment for a combined injury of a posterolateral tibial head fracture and an injury to the anterior cruciate ligament is missing.

METHODS

We present a retrospective study with clinical and radiological analysis of posterolateral fractures in combination with ACL-tear. Impressions with a depth of more than 2 mm and/or a width that outreaches more than half of the posterior horn of the lateral meniscus with additional 3. degree positive pivot-shift-test indicated surgical treatment of the fracture with additional ACL repair or reconstruction. Clinical evaluation included follow-up examination, Visual Analog Scale (VAS), International Knee Documentation Committee Score (IKDC), functional and radiological Rasmussen score.

RESULTS

20 patients were included with a mean age of 43.6 ± 12.4 years. Mean follow-up was 18,2 ± 13,5 months. The fracture was arthroscopically reduced and percutaneously fixed with a screw osteosynthesis (Group 1), reduced via a dorsal approach without (Group 2) or with an autologous bone graft (Group 3). Subjective IKDC score was 79,15 ± 6,07. Functional Rasmussen scores ranged from 27 to 30 (mean 28 ± 2.71). Radiological Rasmussen scores ranged from 16 to 18 points (mean 16.75 ± 1.33). According to IKDC score (p = 0.60), functional Rasmussen score (p = 0.829) and radiological Rasmussen score (p = 0.679) no significant discrepancy between the groups were seen. There was no failure of the ACL graft recorded.

CONCLUSIONS

Posterolateral tibial plateau fractures in combination with an ACL-tear, can cause persistent instability and increase rotational instability. Indication for treatment of these fractures is still under debate. From the biomechanical aspect the lack of more than 50% of the posterior horn of the lateral meniscus and dislocation/depression of more than 2 mm results in an increased rotational instability of the ACL deficient knee. Combined surgical treatment with ACL repair or reconstruction is a safe procedure that results in good, short-term clinical outcome, if our algorithm is followed. In addition this study shows, that majority of posterolateral tibial plateau fractures can be treated arthroscopically.

Comparison of extended lateral approaches to the tibial plateau: The articular exposure of lateral epicondyle osteotomy with and without popliteus tendon vs. fibula osteotomy

BACKGROUND

Comminuted lateral tibial plateau fractures pose a challenge to surgeons, with non-anatomical reductions in 70-89%, involving the posterolateral articular surface. The purpose of this study was to examine the posterolateral joint visibility, using lateral extended approaches, such as the lateral femoral epicondyle osteotomy or the fibula osteotomy. Further, the study aimed to compare the combined osteotomy of the femoral footprints of the lateral collateral ligament (LCL) and popliteus tendon (PLT) to the isolated osteotomy of the femoral LCL footprint or the fibula osteotomy, in terms of posterolateral joint accessibility.

METHODS

Extended lateral (femoral or fibular LCL osteotomy) and posterolateral (additional femoral osteotomy of the PLT tendon) approaches were performed on twelve human cadaver knees. After preparation of each surgical approach, the visible articular surface was marked with diathermy. The tibial plateau was disarticulated and the markings were measured digitally with open-source processing software. Differences in mean values were tested with a paired t-test (p ≤ 0.05).

RESULTS

The greatest articular exposure was achieved with the fibula osteotomy (1011.52 ± 227.05 mm² [86.64 ± 4.84%] compared to the combined osteotomy of LCL and PLT (p = 0.036) or LCL alone (p<0.001). The lateral femoral epicondyle osteotomy of the LCL including the PLT (937.45 ± 237.84 mm² [80.29 ± 8.25%]) exposed a significantly larger articular surface of the lateral tibial plateau than without the PLT (755.71 ± 183.06 mm² [64.73 ± 6.51%], p < 0.001).

CONCLUSION

In direct comparison, the fibula osteotomy provides the largest articular visualization, however at cost of a considerably larger soft tissue damage. While the lateral femoral epicondyle osteotomy of LCL and PLT increases lateral articular visualization, it omits the risk of neurovascular or posterolateral soft tissue damage and therefore represents an important extended approach to treat comminuted lateral plateau fractures.

Arthroscopically assisted and three-dimensionally modeled minimally invasive rim plate osteosynthesis via modified anterolateral approach for posterolateral tibial plateau fractures

AIM

The aim of this study was to describe a new, closed, arthroscopically-assisted reduction of posterolateral tibial plateau fractures with minimally invasive plate osteosynthesis using a plate pre-contoured over a 3D-model based on a CT-scan of the injured tibial plateau and positioned by using a minimal anterolateral approach.

METHODS

A five to six centimeter long curvilinear incision was made over the Gerdy's tubercle. After subcutaneous dissection, the fascia was incised, the ileo-tibial band was split, and the dissection was extended posteriorly. The knee was flexed to 90° and the space between the fibular collateral ligament and the posterolateral plateau rim (para-FCL space) was created. A variable-angle locking compression plate contoured on a 3D-model was inserted flush to the tibial plateau rim. Two cortical screws were placed to ensure support under the area of depression as far posteriorly as possible. Two additional screws were implanted, and a cortical screw was used for the most anterior screw hole. The custom pre-contoured plate based on a person-specific 3D-model, associated with arthroscopy reduction, provides a supporting and containing effect to the posterolateral periarticular fragments and allows a minimally invasive plate osteosynthesis fixation to be performed. This guarantees a proper reduction and fixation without the described limitations and risks associated with the classic approaches.

CONCLUSIONS

This approach should be considered to treat fractures of the posterolateral plateau, isolated or associated with medial tibial plateau fractures, as it could improve the outcome in terms of lower associated risks, better reduction and fixation, and faster and improved patient recovery.

Comparative Analysis of Mechanism-Associated 3-Dimensional Tibial Plateau Fracture Patterns

BACKGROUND

The association between tibial plateau fracture morphology and injury force mechanism has not been well described. The aim of this study was to characterize 3-dimensional fracture patterns associated with hypothesized injury force mechanisms.

METHODS

Tibial plateau fractures treated in a large trauma center were retrospectively reviewed. Three experienced surgeons divided fractures independently into 6 groups associated with injury force mechanisms proposed from an analysis of computed tomographic (CT) imaging: flexion varus, extension varus, hyperextension varus, flexion valgus, extension valgus, and hyperextension valgus. The fracture lines and comminution zones of each fracture were graphically superimposed onto a 3-dimensional template of the proximal part of the tibia. Fracture characteristics were then summarized on the basis of the fracture maps. The association between injury force mechanism and ligament avulsions was calculated.

RESULTS

In total, 353 tibial plateau fractures were included. The flexion varus type pattern was seen in 67 fractures characterized by a primary fracture apex located posteromedially and was frequently associated with concomitant anterior cruciate ligament (ACL) avulsion (44.8%). The extension varus pattern was noted in 60 fractures with a characteristic medial fragment apex at the posteromedial crest or multiple apices symmetrically around the crest and was commonly completely articular in nature (65%). The hyperextension varus pattern was seen in 47 fractures as noted by anteromedial articular impaction, 51% with a fibular avulsion and 60% with posterior tension failure fragments. The flexion valgus pattern was observed in 51 fractures characterized by articular depression posterolaterally, often (58.9%) with severe comminution of the posterolateral cortical rim. The extension valgus patterns in 116 fractures only involved the lateral plateau, with central articular depression and/or a pure split. The hyperextension valgus pattern occurred in 12 fractures denoted by anterolateral articular depression. A moderate positive association was found between flexion varus fractures and ACL avulsions and between hyperextension varus fractures and fibular avulsions.

CONCLUSIONS

Tibial plateau fractures demonstrate distinct, mechanism-associated 3-dimensional pattern characteristics. Further research is needed to validate the classification reliability among other surgeons and to determine the potential value in the diagnosis and formulation of surgical protocols.

A new strategy to fix posterolateral depression in tibial plateau fractures: Introduction of a new modified Frosch approach and a "Barrel hoop plate" technique

AIMS

The articular congruity of tibial plateau has been stressed to be associated with the long-term function outcomes. Approach selection and fixation pattern to manipulate the posterolateral (PL)-depression of tibial plateau are both key issues which trauma surgeons should focus on. In order to provide a strong purchase of PL-depression, we developed a new modified Frosch approach and a "Barrel hoop plate" technique to provide bony reconstruction of PL-depression.

MATERIALS AND METHODS

Eleven consecutive patients of tibial plateau fractures involved in PL-depression were surgically treated at our single level-I trauma center. Our newly designed "Barrel hoop plate" was used to fix the PL-depression via a modified Frosch approach. The demography and treatment information were summarized of all the patients. X-ray and CT-scan of the knee joint were used to assess the reduction after operation. Besides evaluation of the HSS knee score, medial tibial plateau angle(mTPA), posterior slope angle(PSA) and articular step-off were measured to assess the malreduction degrees.

RESULTS

The average operation time was 123 ± 20 min. The mean blood loss was 148 ± 45 mL. The fractures were healed radiographically at 13 ± 1 weeks post-operation. After 15 ± 2 months follow-up, all the patients were pain-free with full range of motion and stable knees. Radiologically, good fracture reduction was achieved in all cases. According to the final assessment, the mTPA, m-PSA and l-PSA were 85° ± 2°, 11° ± 5° and 10° ± 6°, respectively. The average range of motion was 128° ± 10°in flexion and 4° ± 4° in extension, and the average HSS score was 91 ± 3.

CONCLUSION

Our new approach is a modification of the Frosch approach with a decreased soft tissue exposure and a low risk of neurovascular vessel injury. The concurrent application of the "Barrel hoop plate" technique could not only provide a reconstruction of the PL tibial plateau, but also hoop the ruptured tibia plateau rim and secure the depression as a raft. This new technique prevented the PL-tibial plateau reduction loss and the made the patients' early range of motion come true.

Influence of reduction accuracy in lateral tibial plateau fractures on intra-articular friction - a biomechanical study

BACKGROUND

Lateral tibial split fractures (LTSF) usually require surgical therapy with screw or plate osteosynthesis. Excellent anatomical reduction of the fracture is thereby essential to avoid post-traumatic osteoarthritis. In clinical practice, a gap and step of 2 mm have been propagated as maximum tolerable limit. To date, biomechanical studies regarding tibial fractures have been limited to pressure measurement, but the relationship between dissipated energy (DE) as a friction parameter and reduction accuracy in LTSF has not been investigated. In past experiments, we developed a new method to measure DE in ovine knee joints. To determine weather non-anatomical fracture reduction with lateral gap or vertical step condition leads to relevant changes in DE in the human knee joint, we tested the applicability of the new method on human LTSFs and investigated whether the current limit of 2 mm gap and step is durable from a biomechanical point of view.

METHODS

Seven right human, native knee joint specimens were cyclically moved under 400 N axial load using a robotic system. During the cyclic motion, the flexion angle and the respective torque were recorded and the DE was calculated. First, DE was measured after an anterolateral approach had been performed (condition "native"). Then a LTSF was set with a chisel, reduced anatomically, fixed with two set screws and DE was measured ("even"). DE of further reductions was then measured with gaps of 1 mm and 2 mm, and a 2 mm step down or a 2 mm step up was measured.

RESULTS

We successfully established a measurement protocol for DE in human knee joints with LTSF. While gaps led to small though statistically significant increase (1 mm gap:ΔDE compared with native = 0.030 J/cycle, (+ 21%), p = 0.02; 2 mm gap:ΔDE = 0.032 J/cycle, (+ 22%), p = 0.009), this increase almost doubled when reducing in a step-down condition (ΔDE = 0.058 J/cycle, (+ 56%), p = 0.042) and even tripled in the step-up condition (ΔDE = 0.097 J/cycle, (+ 94%), p = 0.004).

CONCLUSIONS

Based on our biomechanical findings, we suggest avoiding step conditions in the daily work in the operating theatre. Gap conditions can be handled a bit more generously.

A Novel Design of a Plate for Posterolateral Tibial Plateau Fractures Based on Computed Tomography Mapping of the Proximal Tibiofibular Joint

Background

We designed a novel plate for the treatment of posterolateral tibial plateau fractures. We first gathered radiological data of the proximal tibiofibular joint to verify the feasibility of the novel plate and provide an anatomical basis.

Material/Methods

Tomographic images of 98 healthy human tibias were obtained retrospectively. The width of the lateral tibial plateau, width of the posterolateral tibial plateau to the sagittal plane of the tibial plateau and width of the proximal tibiofibular joint to the sagittal plane of tibial plateau were measured. The proximal posterolateral tibial bone cortex angle and posterolateral slope-diaphysis angle were also calculated. Paired sample t-test was used for comparing men and women, and left and right sides. We used 2 variables for Pearson correlation analysis between the width of the lateral tibial plateau and other length indices.

Results

There were no statistically significant differences between left and right knees (P>0.05). However, there were statistically significant differences of the 3 length indices between men and women (P<0.05). The length indices were all correlated to the width of the lateral tibial plateau (P<0.01).

Conclusions

This study of the lateral tibial plateau has a high accuracy in anatomical measurement, and our novel plate design is feasible based on the data. The study provided anatomical basis for the novel plate.

Comparison of extended anterolateral approach in treatment of simple/complex tibial plateau fracture with posterolateral tibial plateau fracture

BACKGROUND

Our hospital has recently used the extended anterolateral approach in posterolateral tibial plateau fracture. We compared the clinical effects of this method in Schatzker type II or type V/VI fractures with posterolateral tibial plateau fracture based on our patients.

METHODS

The patients from January 2013 to December 2015 were summarized, and some of them were assisted with arthroscopy. According to Schatzker classification, patients with Schatzker type II fracture were divided into group A; patients with Schatzker type V/VI fracture were divided into group B. The fracture characteristics, operation statistics, and postoperative functional evaluation of each group were compared.

RESULTS

A total of 46 patients were included in the study and were followed up for 23-45 months. There were 24 cases in group A and 22 cases in group B. The operation time and the amount of bleeding were significantly less in group A (P < 0.05). Twelve cases were assisted with arthroscopy including 6 patients in each group. The fracture healing time made no significant difference in the two groups (P > 0.05). All patients experienced no significant influence on daily life. The knee Rasmussen score was 26.8 in group A and 23.5 in group B (P > 0.05), and the knee range motion was 115.5° in group A and 106.6° in group B (P > 0.05). The excellent and good rate of reduction was 91.7% in group A and 81.8% in group B (P > 0.05), but the excellent rate of reduction was 83.3% in group A and 27.3% in group B (P < 0.05). The unfixed rate of posterolateral fracture was 16.7% in group A and 36.4% in group B (P > 0.05). One patient in group B suffered postoperative wound infection.

CONCLUSIONS

The extended anterolateral approach could obtain similar satisfactory clinical results in simple/complex tibial plateau fracture with posterolateral tibial plateau fracture. It seemed that easier operation, better posterolateral fracture reduction, and fixation occurred in relative simple fracture from our cases.

TRIAL REGISTRATION

It was a retrospective study. This study was consistent with the ethical standards of the Second Affiliated Hospital of Zhejiang University Medical College and was approved by the hospital ethics committee and the trial registration number of our hospital was 20170053.

A Novel Design of a Plate for Posterolateral Tibial Plateau Fractures Through Traditional Anterolateral Approach

Biomechanical performance of a newly designed plate for treating posterolateral tibial plateau fractures was compared with three traditional internal fixation devices using finite element analysis (FEA) and biomechanical experiments. Forty synthetic tibias were used to create posterolateral shearing tibial fracture models, which were randomly assigned to groups A–D. The fragments were fixed with two 6.5-mm lag screws (group A), the newly designed plate (group B), a 3.5-mm lateral locking plate (group C), and a posterolateral buttress plate (group D). In the biomechanical experiment, vertical displacement of the posterolateral fragments was measured under axial loads of 500–1500 N. In the FEA, vertical displacement of the posterolateral fragments and stress distribution and maximum stress of each internal fixation were measured under axial loads of 250–750 N. Biomechanically, collective ranges of vertical displacements in the four groups were 0.356 ± 0.089–1.055 ± 0.023 mm at 500 N axial load, 0.651 ± 0.062–1.525 ± 0.03 mm at 1000 N, and 0.903 ± 0.077–1.796 ± 0.04 mm at 1500 N. Differences between the four groups were statistically significant (P < 0.05), except for groups B and C at 1500 N. FEA showed that collective ranges of vertical displacements in the four groups were 0.290–1.425 mm at of 250 N axial load, 0.580–1.680 mm at 500 N, 1.067–1.818 mm at 750 N. Maximum stress of groups A–D were, respectively, 321.940, 132.660, 100.383, and 321.940 MPa under 250 N axial load. Maximum stress of all four internal fixations increased, and the overall trends at 500 and 750 N were consistent with that at 250 N. Posterior, straight fixation was the most reliable. Fixation with the lag screw was least reliable. The new plate and 3.5-mm lateral locking plate exhibited similar control over fragment displacement. The newly designed plate was stable and reliable, indicating its suitability for clinical application.

Extended lateral column tibial plateau fractures. How do we do it?

We describe the operative management of extended lateral column fractures according to the revised three-column classification approach in a step-by-step fashion. We show that direct reduction and stable fixation of extended lateral column tibial plateau fractures via a limited arthrotomy and tibia condyle osteotomy, with the use of free subchondral 2.7 mm locking screws is a reliable technique. Subsequently, diverging VA-LCP locking screws further improve the structural properties. It is a straightforward technique and the single lateral approach (Lazy-S) facilitates direct reduction of the articular surface and stable fixation of the fracture fragments under direct vision with good radiological and fair functional outcome.

Bone microarchitecture of the tibial plateau in skeletal health and osteoporosis

BACKGROUND

Impaired bone structure poses a challenge for the treatment of osteoporotic tibial plateau fractures. As knowledge of region-specific structural bone alterations is a prerequisite to achieving successful long-term fixation, the aim of the current study was to characterize tibial plateau bone structure in patients with osteoporosis and the elderly.

METHODS

Histomorphometric parameters were assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT) in 21 proximal tibiae from females with postmenopausal osteoporosis (mean age: 84.3 ± 4.9 years) and eight female healthy controls (45.5 ± 6.9 years). To visualize region-specific structural bony alterations with age, the bone mineral density (Hounsfield units) was additionally analyzed in 168 human proximal tibiae. Statistical analysis was based on evolutionary learning using globally optimal regression trees.

RESULTS

Bone structure deterioration of the tibial plateau due to osteoporosis was region-specific. Compared to healthy controls (20.5 ± 4.7%) the greatest decrease in bone volume fraction was found in the medio-medial segments (9.2 ± 3.5%, p < 0.001). The lowest bone volume was found in central segments (tibial spine). Trabecular connectivity was severely reduced. Importantly, in the anterior and posterior 25% of the lateral and medial tibial plateaux, trabecular support and subchondral cortical bone thickness itself were also reduced.

CONCLUSION

Thinning of subchondral cortical bone and marked bone loss in the anterior and posterior 25% of the tibial plateau should require special attention when osteoporotic patients require fracture fixation of the posterior segments. This knowledge may help to improve the long-term, fracture-specific fixation of complex tibial plateau fractures in osteoporosis.

[Clinical observation of 3.5 mm T support plate fixation for simple posterolateral tibial plateau fracture by posterolateral inverted L-shaped approach]

Objective

To summarize the effectiveness of 3.5 mm T support plate fixation for simple postero-lateral tibial plateau fractures by posterolateral inverted L-shaped approach.

Methods

Between March 2011 and January 2016, 13 patients with simple posterolateral tibial plateau fracture were treated with 3.5 mm T support plate fixation by posterolateral inverted L-shaped approach. Of 13 cases, 6 were male and 7 were female, aged 28 to 52 years (mean, 43 years). The left side was involved in 5 cases and the right side in 8 cases. The causes of injury were traffic accidents in 6 cases, falls in 3 cases, and falling from height in 4 cases. All of patients had fresh closed fracture by X-ray, CT three dimensional reconstruction, and MRI. According to Schatzker classification, 4 cases were rated as type II and 9 cases as type III. The time between injury and operation was 5-9 days (mean, 7 days).

Results

One case had incision skin necrosis, which was cured after debridement and skin grafting; and primary healing was obtained in the other cases. The patients were followed up 10-16 months (mean, 13 months). The X-ray film showed that the fracture line was blurred at 3 months after operation, and disappeared at 12 months after operation. There was no complications of wound infection, major neurovascular injury, loosening or breakage of internal fixation, and dislocation of joint surface. The Hospital for Special Surgery (HSS) knee function score was 94 (range, 89-97) at last follow-up; all were excellent.

Conclusion

The 3.5 mm T support plate fixation by posterolateral inverted L-shaped approach is one of preferred surgical method for the treatment of simple posterolateral tibial plateau fractures.

A biomechanical evaluation of different fixation strategies for posterolateral fragments in tibial plateau fractures and introduction of the 'magic screw'

BACKGROUND

Posterior plate fixation is biomechanically the strongest fixation method for posterolateral column fracture (PLCF) of the tibial plateau; however, there are inherent deficiencies and risks of a posterior approach. Thus, the 'magic screw' was proposed to enhance fixation stability of the lateral rafting plate used for PLCF. The purpose of this study was to re-examine and compare the stability of different fixation methods for PLCF.

METHODS

Synthetic tibiae models were used to simulate posterolateral split fractures. The fracture models were randomly assigned into three groups: Group A, fixed with posterolateral buttress plates; Group B, with lateral locking compression plates (LCP); and Group C fixed with lateral LCPs and one 'magic screw'. Gradually increased axial compressive loads were applied to each specimen.

RESULTS

There was a mean subsidence hierarchy of the posterolateral fragment at different load levels: Group A had the least subsidence, followed by Group C, and Group B had the most. There were no significant differences in the mean loads at different displacements between Group A and Group C. Group A had the highest axial stiffness. Additionally, there was a significant difference in axial stiffness between Group B and Group C.

CONCLUSION

Biomechanical stability of the combined fixation of the posteriorly positioned lateral rafting plate with the 'magic screw' was much closer to that of posterior plate fixation for split-type PLCF. The necessity of posterior fixation through a posterior approach may be reduced for selected patients.

Flexion-valgus unicondylar tibial plateau depression fracture pattern: Classification and treatment

PURPOSE

The authors have identified a subset of unicondylar tibial plateau depression fracture patterns caused by a flexion-valgus force. The purpose of this study was to describe this fracture pattern and suggest a modified lateral approach that may allow for improved reduction and stabilization.

METHODS

The preoperative radiographs and CT scans of 102 patients who sustained unicondylar tibial plateau fractures (OTA 41B) were reviewed. Twenty-six fracture patients had posterolateral (PL) tibial plateau depression fractures. By medical record review and telephone follow-up, the injury mechanism of the 22 unicondylar tibial plateau fractures was confirmed as a flexion-valgus force. The radiographic features of those cases were analyzed and measured. To address this specific fracture pattern, a modified approach combined with a novel intra-articular osteotomy was applied.

RESULTS

According to the morphological characteristics, this tibial plateau fracture pattern could be divided into two subtypes: type A was a confined, basin-like articular surface depression fracture located in the PL quadrant, and type B was a cancellous fracture involving the PL tibial plateau resulting in a decrease in the posterior slope. One radiographic hallmark of this fracture pattern is an anatomically or a mechanically intact posterior column wall. The novel approach was applied to both types. The postoperative radiographic measurements revealed excellent reduction quality. On axial scans, the distance between the most posterior rafting screw and the tangent line of the tibial plateau rim was 3.0 ± 2.07 mm (from -1.9 to 4.3), and the angulation between them was 8.9 ± 3.02° (from -7.3 to 15.6). These results indicated excellent PL quadrant coverage from the rafting screws.

CONCLUSION

Flexion-valgus force-induced unicondylar tibial plateau depression fracture is a unique injury pattern. We suggest a novel surgical approach to address this injury's key features, which may facilitate exposure and enhance fixation strength.

Posterolateral tibial plateau fractures, how to buttress? Reversed L posteromedial or the posterolateral approach: a comparative cadaveric study

INTRODUCTION

The selection of a surgical approach for buttressing posterolateral tibial plateau fractures is controversial.

OBJECTIVE

This study compared the surgical exposure area between the reversed L posteromedial approach (R-PM) and the posterolateral (PL) approach using the lateral plateau width as a metric.

MATERIALS AND METHODS

Twenty lower extremities from fresh frozen cadavers were included. The R-PM approach was used first and the boundary of the posterior tibial cortex exposure was marked with metal pins. With the same specimens, the PL approach was then performed and the exposure area was marked. After removing all soft tissue, an imaginary line was drawn from the lateral plateau rim anterior to the fibular head (L) to the posteromedial ridge of the tibia (M). Additional metal pins were used to indicate bony reference landmarks at the joint line on the posterior tibial plateau, including the lateral tibial spine (S), the lateral boundary with the PM approach (_LPM) and the lateral boundary with the PL approach (_LPL). All distances were measured using S as the reference point.

RESULTS

The average distance from S to L, referred to as the lateral plateau width (A), was 32.62 mm. The average distances from S to _LPM (B) and from S to _LPL measured as a percentage of A were 43.72 and 81.41%, respectively. The average R-PM approach blind distance from _LPM to _LPL (C) as a percentage of the lateral plateau width was 58.45%, while the distance _LPL to L (D), which represents the invisible blind distance with both approaches, was 15.37% of that width.

CONCLUSIONS

The PL approach provides better access for buttressing the posterolateral tibial plateau fracture than the R-PM approach. With the R-PM approach, the blind area on the lateral plateau which can be accessed only by the PL approach starts approximately at 43.72% and ends at 81.41% of the lateral tibial plateau width. When a fracture is located in this zone, the posterolateral approach is recommended.

Biomechanical efficacy of AP, PA lag screws and posterior plating for fixation of posterior malleolar fractures: a three dimensional finite element study

Background

Clinically there are different fixation methods used for fixation of the posterior malleolar fractures (PMF), but the best treatment modality is still not clear. Few studies have concentrated on this issue, least of all using a biomechanical comparison. The purpose of this study was to carry out a computational comparative biomechanics of three different commonly used fixation constructs for the fixation of PMF by finite element analysis (FEA).

Methods

Computed tomography (CT) images were used to reconstruct three dimensional (3D) model of the tibia. Computer aided design (CAD) software was used to design 3D models of PMF. Finally, 3D models of PMF fixed with two antero-posterior (AP) lag screws, two postero-anterior (PA) lag screws and posterior plate were simulated through computational processing. Simulated loads of 500 N, 1000 N and 1500 N were applied to the PMF and proximal ends of the models were fixed in all degrees of freedom. Output results representing the model von Mises stress, relative fracture micro-motion and vertical displacement of the fracture fragment were analyzed.

Results

The mean vertical displacement value in the posterior plate group (0.52 mm) was lower than AP (0.68 mm) and PA (0.69 mm) lag groups. Statistically significant low amount of the relative micro-motion (P < 0.05) was observed in the posterior plate group.

Conclusions

It was concluded that the posterior plate is biomechanically the most stable fixation method for fixation of PMF.

Reinforcement strategy for lateral rafting plate fixation in posterolateral column fractures of the tibial plateau: The magic screw technique

BACKGROUND

A posterolateral column fracture of the tibial plateau (PLCF) is not uncommon, especially lateral and bicondylar tibial plateau fractures. Currently, there is no consensus on the methods of surgical treatment for PLCF, including the surgical approach or the fixation strategy. Though various posterior approaches have been explored and can allow posterior buttress plate fixation, the necessity of a posterior approach with fixation for PLCFs is increasingly questioned. Meanwhile, there is no literature to analyse the morphological features of PLCFs. None of the available surgical techniques can solve all of the problems of PLCFs.

METHODS

From February 2016 to June 2016, an inconsecutive series of 16 patients who suffered Schatzker type II tibial plateau fractures involving the posterolateral column were selected based on an analysis of the morphological characteristics of PLCFs. The patients were all treated by lateral rafting plate fixation with magic screw implantation through the extended lateral approach.

RESULTS

According to PLCF morphology, 4 patients had mild slope-type depression fractures (MSDF) of the articular surface, and the other 12 patients had block-type splitting fractures (BSF). After a 12-month follow-up period, there were no complications related to the fixation technique and no significant changes in limb alignment. At the final follow-up, the average range of motion (ROM) of the affected knees was 2.3°-125°, and the average HSS score was 94.2.

CONCLUSIONS

The selected patients who suffered Schatzker type II fractures involving the posterolateral column could be successfully treated via lateral rafting plate fixation with the magic screw technique. For PLCF treatment, magic screw fixation is a valuable technique that may reduce the utilization of posterior approaches and posterior fixations.

Plate fixation for Letenneur type I Hoffa fracture: a biomechanical study

BACKGROUND

A coronal fracture of the posterior femoral condyle, also known as a Hoffa fracture, is an unusual injury, and there are only a handful of case reports or series exploring it. The optimal fixation method of these intraarticular fractures remains controversial; improper or unstable fixation usually lead to an unsatisfactory prognosis. The use of posterior-anterior or reversed lag screw fixation is still a popular method. Additional buttress plating is also recommended for fixation of these difficult fractures. The purpose of this study was to compare the mechanical strength of four different fixation patterns for this uncommon fracture.

MATERIAL AND METHODS

Sixteen sawbone simulated models of Letenneur type I Hoffa fractures were created with one of four fixation patterns: two screws implanted in the anterior-posterior (AP) direction or posterior-anterior (PA) direction; one screw in the PA direction with a plate implanted in the posterior position of the distal femoral condyle or with a plate in the lateral position. Biomechanical testing was performed to determine the post-fixation axial stiffness, the maximum load to failure and the fragment vertical displacement for each of the four constructs.

RESULTS

The plate fixation patterns whether implanted in the posterior or lateral position were shown to provide higher overall axial stiffness and load to failure, and less vertical displacement than the other two patterns of pure screw fixation. Among these constructs, the lateral plate fixation was found to provide the highest stiffness and load to failure and the least displacement for the posterior condylar fragments, followed by the posterior plate fixation. The lowest overall stiffness and load to failure and the largest vertical displacement were found in the construct with the AP direction placed screws.

CONCLUSION

It was concluded that the lateral position implanted plate is biomechanically the strongest fixation method for Letenneur type I Hoffa fractures. However, this plate fixation is not recommended for all cases. The choice of internal fixation pattern depends on the surgeons.

The anatomical relationship of the neurovascular structures in direct posterior lateral gastrocnemius split approach for posterolateral tibial plateau fractures

PURPOSE

To evaluate the distances between the incision and neurovascular structures in direct posterior split-gastrocnemius approach for tibial plateau fractures.

METHODS

Thirteen fresh-frozen cadavers were used in the study. The distance between the neurovascular structures medial and lateral to the incision was measured from the tibial joint line and at a level 5 cm distal to the joint line.

RESULTS

The mean distance between the incision and medial neurovascular structures was 10.09 ± 3.47 mm (range 5.63-16.51 mm) at the level of the tibial joint line and 10.39 ± 2.57 mm (range 5.79-14.09 mm) at a level 5 cm distal to the joint line. The mean distance between the incision and the common peroneal nerve was 13.44 ± 4.17 mm (range 6.28-20.72 mm) at the level of the tibial joint line and 19.56 ± 5.24 mm (range 12.58-26.74 mm) at a level 5 cm distal to the joint line.

CONCLUSIONS

In isolated posterolateral tibial plateau fractures, it is possible to apply anatomical reduction and buttress plating on the posterior surface with a direct posterior split-gastrocnemius approach. With a thorough understanding of the regional anatomy, this approach can be safely performed by experienced orthopaedists.

Distal Locking Screws for Intramedullary Nailing of Tibial Fractures

Recently introduced tibial intramedullary nails allow a number of distal screws to be used to reduce the incidence of malalignment and loss of fixation of distal metaphyseal fractures. However, the number of screws and the type of screw configuration to be used remains obscure. This biomechanical study was performed to address this question. Thirty-six Expert tibial nails (Synthes, Oberdorf, Switzerland) were introduced in composite bone models. The models were divided into 4 groups with different distal locking configurations ranging from 2 to 4 screws. A 7-mm gap osteotomy was performed 72 mm from the tibial plafond to simulate a 42-C3 unstable distal tibial fracture. Each group was divided in 3 subgroups and underwent nondestructive biomechanical testing in axial compression, coronal bending, and axial torsion. The passive construct stiffness was measured and statistically analyzed with one-way analysis of variance. Although some differences were noted between the stiffness of each group, these were not statistically significant in compression (P=.105), bending (P=.801), external rotation (P=.246), and internal rotation (P=.370). This in vitro study showed that, when using the Expert tibial nail for unstable distal tibial fractures, the classic configuration of 2 parallel distal screws could provide the necessary stability under partial weight-bearing conditions.

Rim Plating of Posterolateral Fracture Fragments (PLFs) Through a Modified Anterolateral Approach in Tibial Plateau Fractures

Posterolateral fracture fragments in tibial plateau fractures have proven to be particularly difficult to reduce and adequately repair internally through anterior or anterolateral approaches, although they are safer. Posterior and posterolateral approaches offer a direct approach for the reduction and fixation of plates, but they have several limitations. Here, we have proposed a modified anterolateral approach, which ensures a safe and effective technique for the reduction and fixation of posterolateral fracture fragments, aided by our innovative rim plate.

Intra-articular tibial plateau fracture characteristics according to the "Ten segment classification"

BACKGROUND

Currently existing classifications of tibial plateau fractures do not help to guide surgical strategy. Recently, a segment-based mapping of the tibial plateau has been introduced in order to address fractures with a fracture-specific surgical approach. The goal of the present study was to analyze incidence and fracture specifics according to a new 10-segment classification of the tibial plateau.

METHODS

A total of 242 patients with 246 affected knees were included (124 females, 118 males, mean age 51.9±16.1years). Fractures were classified according to the OTA/AO classification. Fracture pattern was analyzed with respect to a 10-segment classification based on CT imaging of the proximal tibial plateau 3cm below the articular surface.

RESULTS

161 Patients suffered an OTA/AO type 41-B and 85 patients an OTA/AO type 41-C tibial plateau fracture. Females had an almost seven times higher risk to suffer a fracture due to low-energy trauma (OR 6.91, 95% CI (3.52, 13.54), p<0.001) than males. In 34% of the patients with affection of the medial tibial plateau, a fracture comminution, primarily due to low-energy trauma (p<0.001), was observed. In type B fractures, the postero-latero-lateral (65.2%), the antero-latero-lateral (64.6%) and the antero-latero-central (60.9%) segment were most frequently affected. Every second type C fracture showed an unique fracture line and zone of comminution. The tibial spine was typically involved (89.4%). A typical fracture pattern of high-energy trauma demonstrated a zone of comminution of the lateral plateau and a split fracture in the medial plateau. The most frequently affected segments were the postero-latero-central (85.9%), postero-central (84.7%), and antero-latero-central (78.8%) segment.

CONCLUSION

Posterior segments were the most frequently affected in OTA/AO type B and C fractures. Acknowledging the restricted visibility of posterior segments, whose reduction and fixation is crucial for long-term success, our findings implicate the use of posterior approaches more often in the treatment of tibial plateau fractures. Also, low-energy trauma was identified as an important cause for tibial plateau fractures.