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

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.

A newly designed anatomical plate for the therapy of posterolateral tibial plateau fracture via a supra-fibular-head approach: a retrospective study

The posterolateral tibial plateau fracture is a special type of intra-articular fracture, for which there is no simple, safe, and effective standardized procedure. In this paper, we evaluate the clinical efficacy and the advantages of the treatment of posterolateral tibial plateau fracture by using our designed proximal lateral tibial rim plate for the posterolateral condyle of the tibial plateau via the space above the fibula head. Thirty-eight patients with posterolateral tibial plateau fractures from June 2018 to June 2021 were retrospectively analyzed. CT scans were used to classify the degree of injury in the included patients. All of them were fixed with reduction using an approach above the fibula head combined with a homemade anatomical plate. The regular postoperative review was performed to instruct functional knee exercises. Postoperative complications were observed and follow-up visits were performed to assess the functional outcome. A total of 38 patients with posterolateral tibial plateau fractures, 13 males and 25 females were included in the study. All patients were followed up for 13-26 months, with a mean of 15.3 months. There were no postoperative complications such as numbness of the limb, knee joint instability, etc. X-ray review showed that the fractures were all healed, and the healing time was 10-16 weeks, with an average of 12.1 weeks; none of the internal fixation loosening and loss of articular surface occurred during the follow-up period. At the last follow-up, according to the HSS knee function score criteria, the scores were 79-98, with an average of 91.3. The HSS score presented excellent in 34 cases (89%) and good in 4 cases (11%). The Rasmussen score was graded as excellent in 29 cases (76%) and good in 9 cases (24%). In conclusion, The treatment of posterolateral tibial plateau fractures by an approach above the fibula head has the advantages of simplicity and safety, small trauma, and no risk of vascular and nerve injuries, and the anatomical proximal lateral tibial rim plate can play a direct and effective supporting role for the bone fragments of the posterolateral condyle, and the combination of both of them has obvious advantages in the treatment of posterolateral condylar fracture of the tibial plateau, and it is a method worth borrowing and popularizing.

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 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.

Depression fractures of the posterolateral tibial plateau: Treatment by lateral femoral epicondyle osteotomy approach

OBJECTIVE

The best surgical exposure and fixation method for fractures affecting the posterolateral corner of the tibial plateau remain debatable. This study describes a surgical approach to treat lateral depressions of the posterolateral tibial plateau with or without rim involvement by osteotomy of the lateral femoral epicondyle associated with osteosynthesis with a one-third tubular horizontal belt plate to stabilize the fracture fragment.

METHOD

We evaluated 13 patients with fractures of the tibial plateau affecting the posterolateral region. Assessments included the degree of the depression (in millimeters), quality of the reduction, complications, and function.

RESULTS

All fractures and osteotomies consolidated. The patients had a mean age of 48 years and were mostly men (n=8). Regarding the quality of the reduction, the mean reduction obtained was 15.8 mm, and 8 patients achieved anatomical reduction. The mean (± standard deviation) Knee Society Score was 92±13 (range 65-100), and the mean Function Score was 95±9.6 (range 70-100). The mean Lysholm Knee Score was 92±11.7 (range 66-100), and the mean International Knee Documentation Committee Score was 85±12.6 (range 63-100). All these scores reflect good results. None of the patients developed superficial or deep infection or presented healing disorders. Sensitive or motor complications of the fibular nerve were not observed.

CONCLUSIONS

In this series of patients with depression fractures of the posterolateral tibial plateau, a surgical approach through osteotomy of the lateral femoral epicondyle allowed direct reduction and stable osteosynthesis of the fractures without functional impairment.

3D printing combined with anteroposterior cannulated screws for the treatment of posterolateral tibial plateau fracture

PURPOSE

This study aimed to compare the effects of conventional surgery and three-dimension (3D) printing technology-assisted surgery in the treatment of posterolateral tibial plateau fractures (PTPF).

METHODS

A cohort of 61 patients afflicted with PTPF, spanning from June 2015 to October 2021, was enrolled. They were divided randomly into two groups: 31 cases of 3D printing group, 30 cases of conventional group. The personalized 3D-printed models were used to simulate the surgical procedures in 3D printing group. The demographic characteristics and clinical data were recorded, encompassing operation duration, intraoperative blood loss, intraoperative fluoroscopy shoots and fracture union time. The radiographic outcomes were gauged, encompassing tibiofemoral angle (FTA), tibial plateau angle (TPA), posterolateral slope angle (PSA) and Rasmussen's anatomical score. The functional outcomes were assessed at the 12-month postoperative juncture, encompassing range of motion, Hospital for Special Surgery (HSS) score and Rasmussen's functional score. Furthermore, fracture complications were evaluated,, encompassing infections, traumatic osteoarthritis, and delayed union.

RESULTS

The 3D printing group exhibited the operation time of 95.8 ± 30.2 min, intraoperative blood loss of 101.1 ± 55.3 ml, and intraoperative fluoroscopy shoots of 6.3 ± 2.3 times, while the conventional group recorded respective values of 115.5 ± 34.0 min, 137.0 ± 49.2 ml and 9.13 ± 2.5 times. Noteworthy disparities were evident between the conventional and 3D printing groups (p < 0.05). Furthermore, in comparison to the conventional group, the 3D printing group exhibited commendable radiological and functional outcomes both immediately and 12 months post-surgery, although statistical significance was not attained. Moreover, the 3D printing group experienced a paucity of complications compared to the conventional group, although without achieving statistical significance.

CONCLUSION

This study demonstrated the clinical feasibility of 3D printing combined with anteroposterior cannulated screws for the treatment of posterolateral tibial plateau fracture.

The study of biomechanics and finite element analysis on a novel plate for tibial plateau fractures via anterolateral supra-fibular-head approach

For Schatzker type II split-depressed tibial plateau fractures involving the fractures of anterolateral and posterolateral columns (APC), the optimal fixation scheme is controversial. The objectives of this study were: (1) to introduce a newly designed plate for treating APC fractures via biomechanical tests and finite element analysis (FEA), and (2) to compare it with two conventional fixation methods. APC fracture models were created and randomly assigned to three groups (Groups A-C). Group A was fixed with a 3.5-mm lateral locking plate, Group B was fixed with a 3.5-mm lateral locking plate and two 3.5-mm cannulated screws (hybrid fixation). Group C was fixed with the newly designed plate. It is an arched locking plate for fixing the lateral tibial plateau via the anterolateral supra-fibular-head approach. Each fracture model experienced a gradually increasing axial compressive load ranging from 250 to 750 N using a customized indenter. Biomechanical analysis demonstrated that the newly designed plate showed the minimum displacement among the three methods, followed by the hybrid fixation method. Conversely, the 3.5-mm lateral locking plate displayed the maximum displacement in APC fractures (p < 0.05). FEA results indicated that at 750 N, the maximum displacements for Groups A-C were measured as 3.06 mm, 2.74 mm, and 2.08 mm, respectively. Moreover, the maximum stresses recorded for the implant in Groups A-C at 750 N were 208.32 MPa, 299.59 MPa, and 143.26 MPa, while for the bone, they were 47.12 MPa, 74.36 MPa, and 40.01 MPa. The overall trends at 250 N and 500 N were consistent with those observed at 750 N. In conclusion, due to good biomechanical performance and FEA results, the newly designed plate represents a promising choice for managing APC fractures of the tibial plateau.

Rim plate in the treatment of hyperextension tibial plateau fracture: surgical technique and a series of cases

BACKGROUND

The existence of a "bare area" at the anterior plateau has been observed in cases where anteromedial and/or anterolateral proximal tibial locking plates are used for fixation in the treatment of hyperextension tibial plateau fractures (HTPF). The objective of this study is to introduce the rim plate fixation technique and evaluate its clinical efficacy.

METHODS

A retrospective analysis was conducted on HTPF patients who underwent treatment with a combination of rim plate and proximal tibial locking plate at our hospital between April 2015 and December 2019. All patients were followed up for a minimum of one year. Open reduction and internal fixation were performed using anteromedial/posteromedial and/or anterolateral approaches for all cases. The surgical strategies employed for rim plate fixation were introduced, and both radiographic and clinical outcomes were assessed.

RESULTS

Thirteen patients were enrolled in the study, with an average follow-up time of 4.3 years. Satisfactory reduction was achieved and radiographically maintained in all cases. Additionally, all patients exhibited satisfactory clinical functions, as evidenced by a mean hospital for special surgery (HSS) knee score of 96.2 ± 2.0 (range: 90-98). Furthermore, no wound complications or implant breakage were observed in this series.

CONCLUSION

The combination of the rim plate and proximal tibial plate proved to be an effective fixation configuration, resulting in satisfactory clinical outcomes.

Posteromedial Submeniscal Arthrotomy and Fixation with a Posteromedial Rim Plate in a Comminuted Medial Tibial Plateau Fracture

Medial tibial plateau fractures generally present as simple metaphyseal fractures; however, certain cases may present as comminuted articular fractures. Medial and posteromedial anatomical plates have traditionally been used for their management; nevertheless, not all cases can be successfully managed using these implants. We present a comminuted posteromedial Schatzker type VI tibial plateau fracture case. Direct visualization and subsequent fixation using a posteromedial rim plate were achieved through a posteromedial approach and submeniscal arthrotomy. The adequate joint reduction and the obtained stability allowed satisfactory clinical and radiological outcomes. This variation of the classic posteromedial approach and the use of a posteromedial rim plate provide an alternative when facing comminuted medial tibial plateau fractures.

Influence of articular step-off on contact mechanics in fractures of the posterolateral-central tibial plateau - a biomechanical study

BACKGROUND

The posterior quadrants of the tibial plateau are frequently involved in OTA type C tibial plateau fractures. The biomechanical influence of a residual articular step-off of the posterolateral-central (PLC) segment, which is difficult to visualize intraoperatively, remains unclear. Therefore, aim of this study was to investigate the contact area and stress of the tibial plateau in cases of different articular step-offs of the PLC segment.

METHODS

Seven human cadaveric knees were used to simulate articular impressions of the PLC segment with step-offs of 1 mm, 3 mm, and 5 mm. The knees were axially loaded up to 150 N during a total of 25 dynamic cycles of knee flexion up to 90°. Pressure mapping sensors were inserted into the medial and lateral joint compartments beneath the menisci to measure articular contact area and stress.

RESULTS

Between 60° and 90° of knee flexion, increasing PLC segment impressions of the tibial plateau led to increasing contact stress and a significantly reduced contact area. The largest decrease in the contact area was 30 %, with an articular step-off of 5 mm (0.003). An increase in contact stress, especially from a 3-mm step-off, was measured, with a doubling of the mean contact stress at 3-mm and 5-mm step-offs and 90° knee flexion (p = 0.06/0.05).

CONCLUSION

From a biomechanical point of view, posterior impressions of the PLC segment greater than a 1-mm step-off should be addressed as anatomically as possible, especially in active patients with the need for higher knee flexion angles.

[Application of a new universal locking anatomical plate in treatment of tibial plateau posterolateral column fractures]

OBJECTIVE

To investigate the effectiveness of a new tibial plateau posterolateral column universal locking anatomical plate (hereinafter referred to as "new universal locking anatomical plate") in the treatment of tibial plateau posterolateral column fractures.

METHODS

Between October 2020 and December 2021, 14 patients with tibial plateau posterolateral column fracture were treated with a new universal locking anatomical plate. There were 7 males and 7 females with an average age of 59 years ranging from 29 to 75 years. There were 5 cases on the left side and 9 cases on the right side. The causes of injury included falling from height in 5 cases, traffic accident in 7 cases, and other injuries in 2 cases. The time from injury to operation ranged from 3 to 10 days, with an average of 6 days. According to Schatzker classification, there were 4 cases of type Ⅱ, 8 cases of type Ⅴ, and 2 cases of type Ⅵ. All fractures involved the posterolateral tibial plateau. Three column classification: two columns (anterolateral column+posterior column) in 4 cases, three columns in 10 cases. The operation time, intraoperative blood loss, fracture healing, and complications were recorded. The reduction of tibial plateau fracture was evaluated by Rasmussen radiographic score, and the recovery of knee function was evaluated by Hospital for Special Surgery (HSS) score.

RESULTS

All 14 cases completed the operation successfully. The operation time was 95-180 minutes, with an average of 154 minutes, and the intraoperative blood loss was 100-480 mL, with an average of 260 mL. All patients were followed up 6-19 months, with an average of 12.5 months. All fractures healed, and the healing time was 15-24 weeks, with an average of 18.7 weeks. During the follow-up, there was 1 case of common peroneal nerve palsy and 1 case of traumatic osteoarthritis. There was no other complication such as vascular injury, incision infection, deep venous thrombosis of lower limbs, heterotopic ossification, bone nonunion, and failure of internal fixation. The reduction of tibial plateau fractures was good immediately after operation, and the Rasmussen radiological score was 10-18, with an average of 15.7; 3 cases were excellent, 10 cases were good, and 1 case was fair, with an excellent and good rate of 92.9%. The scores and grades of HSS at 3 months after operation and at last follow-up significantly improved when compared with those before operation ( P<0.05). There was no significant difference between 3 months after operation and last follow-up ( P>0.05).

CONCLUSION

For the fractures involving the posterolateral column of the tibial plateau, the new universal locking anatomical plate can provide strong fixation, satisfactory postoperative fracture reduction, and good recovery of knee 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.

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.

Intra- and inter-observer reliability assessment of widely used classifications and the "Ten-segment classification" of tibial plateau fractures

BACKGROUND

Ten-segment classification provides a different approach to the evaluation of tibial plateau fractures. The purpose of this study was to assess the intra- and inter-observer reliability of three widely used classification systems (Schatzker, Arbeitsgemeinschaft für Osteosynthesefragen (AO/OTA), and the updated three-column concept (uTCC)) with ten-segment classification in two-dimensional computed tomography (2D-CT) and three-dimensional computed tomography (3D-CT).

METHOD

Ninety 2D-CT and 3D-CT scans of patients with tibial plateau fractures were included in this retrospective cohort study. The included data were independently classified by six observers of different years of seniority and were independently observed and classified again after eight weeks. Inter-observer and intra-observer reliability of the four fracture classifications made by the six observers was analyzed using the kappa statistic. Kappa values were interpreted according to the categorical rating by Landis and Koch.

RESULTS

When the inter-observer reliability was based on 2D-CT/3D-CT analysis, the mean Kappa values for the Schatzker, AO/OTA, uTCC, and ten-segment classification were 0.64/0.66, 0.56/0.59, 0.53/0.65, and 0.60/0.73, respectively. When intra-observer reliability was based on 2D-CT/3D-CT, the mean Kappa values for the Schatzker, AO/OTA, uTCC, and ten-segment classification were 0.68/0.83, 0.69/0.83, 0.74/0.85, and 0.80/0.91, respectively.

CONCLUSIONS

The use of 3D-CT is important for the reliable diagnosis and recognition of tibial plateau fracture features compared to 2D-CT. When using 3D-CT, ten-segment classification showed high intra- and inter-observer agreement.

A New Three-Dimensional Classification of Proximal Tibiofibular Fractures: A Multicenter Study

Objectives

To propose an updated definition of proximal tibia and fibula fracture (PTFF) and establish a three‐dimensional (3D) structure‐based classification of PTFF.

Methods

In total, 1358 adult patients (837 males and 521 females; 43.61 ± 15.13 years， 1364 affected knees) who were diagnosed with PTFF at the departments of orthopaedic surgery of four hospitals from January 2010 to December 2019 were enrolled. The new classification of PTFF, termed Wu classification, included three parts: classification of columns in the horizontal plane, regions in the frontal plane, and segments in the sagittal plane. All PTFFs were classified according to Schatzker, Luo, and Wu classification systems. Additionally, the incidence and characteristics of PTFFs were analyzed.

Results

The major internal structural fractures of PTFF were tibial plateau fracture (TPF) only (725, 53.15%), TPF and proximal fibular fracture (274, 20.09%), and isolated avulsion fracture of the posterior cruciate ligament (PCL) (189, 13.86%). Approximately a quarter of PTFF cases could not be classified using Schatzker or Luo classifications, but all PTFF cases could be classified using Wu classification. The most frequent PTFFs included all four columns in region IV, segment 2 (235, 17.23%); the posterolateral and posteromedial columns in region II, segment 2 (191, 14.00%); and the lateral and posterolateral columns in region IV, segment 2 (136, 9.97%). Isolated avulsion fracture of the anterior cruciate ligament (ACL) was categorized as three injury types, most of which involved the lateral and medial columns in region II, segment 1 (40/63, 64%). More than 97% of cases of isolated fractures of the PCL involved the posterolateral and posteromedial columns in region II, segment 2. The most frequent combined avulsion fracture of the ACL and PCL included all four columns in region II, segment 2 (18/24, 75%). All of the isolated avulsion fractures of the ACL were located in segment 1, and all those of the PCL in segment 2. The most common type of isolated proximal fibular fracture involved the posterolateral column in region III, segment 2 (23/26, 88%). The most frequent combined TPF and proximal fibular fracture involved all four columns in region IV, segment 2 (107/274, 39.05%).

Conclusions

All cases of PTFF could be classified by the new 3D Wu classification which should be beneficial for clinical diagnosis, guidance of treatment, statistical analysis, academic communication, and prognosis, and the most frequent PTFF involved all four columns in region IV, segment 2.

A modified Frosch approach for posterior tibial plateau fractures: Technical note and case series

Achieving the best possible articular congruity following a tibial plateau (TP) fracture is associated with better long-term functional outcomes; TP has an essential role in the movements of the knee joint and is well established that a not optimal reduction leads to articular instability and early osteoarthritis. In recent times, 3D reconstruction from CT scan has greatly contributed to improve the surgical treatment of these fractures since an accurate preoperative plan gives the possibility to decide the best interventional strategy before the surgical incision. Reduction of the posterior part of tibial plateau is not easily achievable with standard surgical access. Several posterolateral approaches, proposed by authors such as Frosch and Lobenhoffer, have been described over the years; these approaches can be divided into 2 groups: with or without osteotomy of the fibula. Main disadvantages of these techniques are the large skin incision, the difficulty of exposing the lateral face of the tibia, the high frequency of damages of the posterolateral TP corner, and in some cases the necessity of performing fibular head osteotomy . The surgical approach presented in this paper is a simple innovation of the well-known Frosch approach: skin incision is about 12 centimeters in length and runs in a "S" shape with the center positioned over the head of the fibula. It starts 2 centimeters laterally to the tibial crest 6 centimeters below the tibial tuberosity and is directed proximally, curving posteriorly at the level of fibular head and returning straight in the most proximal part; it terminates 4 centimeters posteriorly the lateral femoral condyle. This innovative approach allows the trauma surgeon to achieve an optimal exposure and control of posterior tibial plateau fractures, with the great advantage of being able to treat the lateral tibial plateau with the same surgical incision.

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.