PurposeTo introduce the concept of fracture reduction with positive medial cortical support and its clinical and radiological correlation in geriatric unstable pertrochanteric fractures.MethodsA retrospective analysis of 127 patients (32 men and 95 women, with mean age 78.7 years) with AO/OTA 31A2.2 and 2.3 hip fractures treated with cephalomedullary nail (PFNA-II or Gamma-3) between July 2010 and June 2013 was performed. They were classified into three groups according the grade of medial cortical support in postoperative fracture reduction (positive, neutral, and negative). The positive cortex support was defined that the medial cortex of the head–neck fragment displaced and located a little bit superomedially to the medial cortex of the shaft. If the neck cortex is located laterally to the shaft, it is negative with no cortical buttress, and if the two cortices contact smoothly, it is in neutral position. The demographic baseline, postoperative radiographic femoral neck–shaft angle and neck length, rehabilitation progress and functional recovery scores of each group were recorded and compared.ResultsThere were 89 cases (70 %) in positive, 26 in neutral, and 12 in negative support. No statistical differences were found between the three groups among patient age, sex ratio, prefracture score of activity of daily living, walking ability score, ASA physical risk score, number of medical comorbidities, osteoporosis Singh index, fracture reduction quality (Garden alignments), and the position of lag screw or helical blade in femoral head (TAD). In follow-up, patients in positive medial cortical support reduction group had the least loss in neck–shaft angle and neck length, and got ground-walking much earlier than negative reduction group, with good functional outcomes and less hip–thigh pain presence.ConclusionFracture reduction with nonanatomic positive medial cortical support allows limited sliding of the head–neck fragment to contact with the femur shaft and achieve secondary stability, providing a good mechanical environment for fracture healing.

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.

Background: Hoffa fractures, coronal-plane fractures involving the distal femoral condyles, are unstable, intra-articular fractures. The aim of this study was to define the location and frequency of fracture lines and comminution zones in Hoffa fractures using computed tomography (CT) mapping in both 2-dimensional and 3-dimensional contexts. Methods: Seventy-five Hoffa fractures (OTA/AO types 33B3.2 and 33B3.3) were retrospectively reviewed. The directions of fracture lines were characterized in the axial and sagittal CT planes. CT images for all fractures were superimposed on one another and oriented to fit a standard template. Mapping of fracture lines and comminution zones in both the axial and sagittal planes was performed. A 3-dimensional map was created by reducing reconstructed fracture fragments to fit to a model of the distal aspect of the femur. Results: This study included 1 bicondylar and 74 unicondylar (26 medial and 48 lateral) Hoffa fractures. Comminuted fractures accounted for 35.5% of all fractures and 44.9% of lateral fractures. Axial fracture mapping demonstrated that fracture lines were concentrated in the middle-third area of the lateral condyle but were less concentrated and with greater variation in the medial condyle. The mean angle of fracture lines with respect to the posterior condylar axis was 34.4° and 29.0° in the lateral and medial femoral condyles, respectively. Sagittal fracture mapping also demonstrated that fracture lines were concentrated in the middle third of the lateral condyle but were less concentrated in the medial condyle. The mean angle of fracture lines with respect to the posterior cortex of the distal femoral shaft was 23.1° and 19.3° in the lateral and medial condyles, respectively. Three-dimensional mapping demonstrated comminution zones commonly occurring in the weight-bearing zone of the lateral condylar articular surface. Conclusions: Hoffa fractures occurred more frequently in the lateral femoral condyle. In the axial plane, fractures commonly extended from anterolateral to posteromedial in the lateral condyle and from anteromedial to posterolateral in the medial femoral condyle. In the sagittal plane, fractures traversed from anteroinferior to posterosuperior. Articular comminution was more commonly seen in lateral condylar fractures and concentrated in the weight-bearing zone of the articular surface. Clinical Relevance: Research in this area is imperative for optimal preoperative planning, such as for the selection of surgical approach and fixation constructs. Our findings lend insight into fracture morphology, which can assist with fracture classification and the design of biomechanical studies, ultimately aiding in treatment.

Aims Tibial plateau fractures (TPFs) are complex injuries around the knee caused by high- or low-energy trauma. In the present study, we aimed to define the distribution and frequency of TPF lines using a 3D mapping technique and analyze the rationalization of divisions employed by frequently used classifications. Methods In total, 759 adult patients with 766 affected knees were retrospectively reviewed. The TPF fragments on CT were multiplanar reconstructed, and virtually reduced to match a 3D model of the proximal tibia. 3D heat mapping was subsequently created by graphically superimposing all fracture lines onto a tibia template. Results The cohort included 405 (53.4%) cases with left knee injuries, 347 (45.7%) cases with right knee injuries, and seven (0.9%) cases with bilateral injuries. On mapping, the hot zones of the fracture lines were mainly concentrated around the anterior cruciate ligament insertion, posterior cruciate ligament insertion, and the inner part of the lateral condyle that extended to the junctional zone between Gerdy’s tubercle and the tibial tubercle. Moreover, the cold zones were scattered in the posteromedial fragment, superior tibiofibular syndesmosis, Gerdy’s tubercle, and tibial tubercle. TPFs with different Orthopaedic Trauma Association/AO Foundation (OTA/AO) subtypes showed peculiar characteristics. Conclusion TPFs occurred more frequently in the lateral and intermedial column than in the medial column. Fracture lines of tibial plateau occur frequently in the transition zone with marked changes in cortical thickness. According to 3D mapping, the four-column and nine-segment classification had a high degree of matching as compared to the frequently used classifications. Cite this article: Bone Joint Res 2020;9(6):258–267.