Intra-operative identification of a temporal bone fracture line during cochlear implant surgery: a case report.

BACKGROUND: Temporal bone fractures are divided into otic capsule sparing and otic capsule involving fractures. In the latter, hearing loss, facial nerve paralysis, cerebrospinal fluid leak and meningitis have been reported to occur. The impact of hearing loss can be devastating, especially when occurring in children, with significant risk to speech development and sound localization. In the event of hearing loss, early rehabilitation is therefore of paramount importance. Identification of an intra-operative fracture line with available images and the outcome of such cases has not been reported. CASE PRESENTATION: We present the case of a 31-month-old male with an otic capsule involving temporal bone fracture, who presented with ipsilateral profound hearing loss. After all required work-up had been performed, he was admitted for a cochlear implant insertion. Per- operatively, a clear fracture line was seen at the round window niche, but a normal insertion was performed despite the anticipated potential ossification at the fracture line. The dreaded complications of cerebrospinal fluid otorrhea or non-auditory stimulation post-implant did not occur. The peculiarity of this case was its rarity, which was demonstrated by clear images that showed the fracture line on preoperative imaging and intraoperatively. CONCLUSION: Cochlear implantation in the presence of a visible fracture line is feasible and the surgical procedure must not be aborted at its discovery. In these cases, post-operative bacterial meningitis can occur and should be treated aggressively with systemic antibiotics to avoid contralateral ossification of the labyrinth due to labyrinthitis.

Retention of teeth in the fracture gaps of the mandible: a retrospective analysis.

OBJECTIVES: Since the introduction of miniplate osteosynthesis and the use of prophylactic antibiotics, the complication rate related to the teeth in the fracture gap has significantly decreased. Currently, there are still no established guidelines for the management of such teeth in mandibular fracture lines. However, the long-term viability of these teeth within the fracture gap remains uncertain. Therefore, this study aimed to assess the survival rate of teeth located within the mandibular fracture line and evaluate related follow-up treatments over a minimum period of one year. MATERIALS AND METHODS: This retrospective study examined 184 patients who underwent surgical treatment for mandibular fractures between January 2018 and December 2021. A total of 189 teeth located in the fracture line were analyzed. Clinical and radiological parameters were collected, including patient age and gender, fracture etiology and location, intraoperative tooth treatment, as well as complications related to both the fracture and the affected teeth in long term. RESULTS: Most of the examined teeth remained uneventful, with postoperative tooth-related complications seen in 14 (7.4%) teeth. The most common complications were symptomatic apical periodontitis (n = 9, 4.8%) and increased tooth mobility (n = 3, 1.5%). A correlation was found between complications and trauma-related tooth luxation (p = 0.002, OR = 15.2), as well as prior teeth connected to retainers or orthodontic appliances (p = 0.001, OR = 10.32). CONCLUSION: Tooth-related complications are rare when intact teeth are retained within the fracture gap. Therefore, unless there is a definitive intraoperative indication for extraction, it is recommended to preserve the teeth in the fracture line. CLINICAL RELEVANCE: Intact teeth in the fracture line of the mandible should not be primarily extracted.

Tooth in the line of a mandibular fracture: Retain it or remove it? Clinical case report.

Defining the prognosis and treatment plan for teeth in the line of a mandibular fracture is a challenge for the maxillofacial surgeon. The periodontal ligament may provide a communication with the oral cavity and become a pathway for infection. There is currently no consensus on the management of teeth in mandibular fracture lines. This report outlines a case where a tooth was successfully retained in the line of fracture as well as providing a review of the literature on the best-accepted treatments for this scenario.

Fracture lines and comminution zones in acetabular fractures based on three dimensional computed tomography.

PURPOSE: To characterize the fracture patterns of acetabular fractures and create fracture maps and comminution zones based on three-dimensional (3D) computed tomography (CT) images. METHODS: Sixty-eight computed tomography images of 67 patients (47 male [70.1%] and 20 female [29.9%], mean age: 45.2 ± 17.2 [range, 18-85 years] with the diagnosis of intra-articular acetabulum fracture were analyzed. Individual fracture lines were drawn and superimposed to a healthy acetabular template according to Judet-Letournel and simplified fracture classification systems. Fracture line, comminution zone, and heat maps were created using the computed tomography mapping technique. RESULTS: Fracture lines were distributed mainly in a horizontal and oblique orientation, which concentrated in the anteroinferior part of the joint in anterior fractures. Posterior fractures mostly had an oblique orientation, which lied between the acetabular dome and middle part of the posterior wall. In complex fractures, fracture lines were concentrated just above the cotyloid fossa, acetabular dome, and posterosuperior part of the acetabulum. The most common comminuted zones were around the central area of the articular surface and the anterior wall in anterior fractures, between the cotyloid fossa and dome in complex fractures, and the upper half posterior wall. CONCLUSION: Fracture patterns and comminution zones of acetabular fractures displayed certain characteristics. Some areas had higher comminution zones, and some areas remained intact in repeatable fracture patterns. These results may help surgeons in fixing acetabular fractures, designing new implants, and placement of acetabular component while performing THA after acetabular fractures.

Treatment of ankylosing spondylitis complicated with a thoracolumbar Andersson lesion by posterior closed osteotomy, debridement and fusion through the fracture line.

BACKGROUND: An Andersson lesion (AL) is a fatigue fracture occurring across three columns in ankylosing spondylitis (AS), resulting in spinal pseudarthrosis (SP) formation, most commonly in the thoracolumbar segment. However, there is still great controversy and few reports on the best surgical method for the treatment of AS combined with thoracolumbar AL. The purpose of this study was to investigate the efficacy of posterior closed osteotomy, debridement and fusion through the fracture line for the treatment of this disease. METHODS: The clinical data of 13 patients (male 8, female 5, mean age 50.6 years) with AS combined with thoracolumbar AL treated with posterior closed osteotomy, debridement and fusion through the fracture line were retrospectively analysed. The following parameters of the full-length lateral spine radiographs were measured preoperatively and at the last follow-up: cervical 7 tilt (C7T), global kyphosis (GK), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), local kyphosis (LK), angle of the fusion levels (AFL), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS) and sagittal vertical axis (SVA). The visual analog scale (VAS), Oswestry disability index (ODI) and Scoliosis Research Society-22 (SRS-22) scores were recorded preoperatively and at the last follow-up. RESULTS: The mean operation time was 345 min, the mean blood loss was 673 mL, and the mean follow-up time was 21.9 months. Compared with the preoperative values, the C7T, GK, TK, TLK, LK, AFL, PT, SS and SVA values of all patients were significantly improved at the last follow-up (P < 0.05); GK improved from 81.62 ± 16.11 to 50.15 ± 8.55, with an average of 31° of correction (F = 75.945, P<0.001). The VAS, ODI and SRS-22 scores also significantly improved (P < 0.05). At the last follow-up, bone fusion was found in all fracture ends. One patient developed numbness in the lower limbs after surgery and recovered after 3 months of rehabilitation; none of the remaining patients experienced postoperative complications. CONCLUSIONS: Posterior closed osteotomy, debridement and fusion through the fracture line completely removes the necrotic tissue around the SP, relieves symptoms, and corrects kyphosis simultaneously. It reduces the tension behind the fracture line or changes the tension into compressive stress, enabling stable repair of the fracture and avoiding anterior surgery. It is a safe and effective operation.

Fracture line distribution in femoral head fractures: a complement to Pipkin, Brumback, and AO/OTA classifications.

PURPOSE: This study aimed to explore the fracture line distribution and validate fracture classifications of Femoral head fractures (FHFs). MATERIALS AND METHODS: A total of 209 FHFs were reviewed retrospectively. Subjects were classified by associated injuries and commonly used fracture classifications (Pipkin, Brumback, and AO/OTA), and the universality degree of classifications was evaluated. The fracture line directions were determined in the coronal and axial CT planes. 3D mapping analysis of fracture lines was performed separately by each group. 3D maps were employed to analyze the discrimination degree of inter-subtype classifications and create a new classification. The subjects were subsequently reclassified. Correlations between classifications were analyzed to determine the matching degree of the three classifications. RESULTS: The universality degrees were 98.6% (pipkin), 44.5% (Brumback), and 94.3% (AO/OTA). The cases of (100%) Brumback and (98.5%) AO/OTA can be classified by Pipkin. The mean angles of fracture lines to the coronal and axial axis of primary compressive trabeculae were 20.25° and 54.56°. The discrimination degrees of inter-subtype of classifications were 0 (Pipkin), 60% (Brumback), and 33% (AO/OTA). A new classification with three regions and five types was created on 3D maps. Pipkin and AO/OTA matched one region, while Brumback matched two regions. CONCLUSIONS: There were three distributed fracture regions in FHFs that mismatched Pipkin, Brumback, and AO/OTA classifications. The new classification, based on morphometric features of FHFs, could compensate for the shortcomings of commonly used classifications, improving their applicability in treating FHFs.

Standardized artificially created stable pertrochanteric femur fractures present more homogenous results compared to osteotomies for orthopaedic implant testing.

BACKGROUND: With regard to biomechanical testing of orthopaedic implants, there is no consensus on whether artificial creation of standardized bone fractures or their simulation by means of osteotomies result in more realistic outcomes. Therefore, the aim of this study was to artificially create and analyze in an appropriate setting the biomechanical behavior of standardized stable pertrochanteric fractures versus their simulation via osteotomizing. METHODS: Eight pairs of fresh-frozen human cadaveric femora aged 72.7 ± 14.9 years (range 48-89 years) were assigned in paired fashion to two study groups. In Group 1, stable pertrochanteric fractures AO/OTA 31-A1 were artificially created via constant force application on the anterior cortex of the femur through a blunt guillotine blade. The same fracture type was simulated in Group 2 by means of osteotomies. All femora were implanted with a dynamic hip screw and biomechanically tested in 20° adduction under progressively increasing physiologic cyclic axial loading at 2 Hz, starting at 500 N and increasing at a rate of 0.1 N/cycle. Femoral head fragment movements with respect to the shaft were monitored by means of optical motion tracking. RESULTS: Cycles/failure load at 15° varus deformation, 10 mm leg shortening and 15° femoral head rotation around neck axis were 11324 ± 848/1632.4 ± 584.8 N, 11052 ± 1573/1605.2 ± 657.3 N and 11849 ± 1120/1684.9 ± 612.0 N in Group 1, and 10971 ± 2019/1597.1 ± 701.9 N, 10681 ± 1868/1568.1 ± 686.8 N and 10017 ± 4081/1501.7 ± 908.1 N in Group 2, respectively, with no significant differences between the two groups, p ≥ 0.233. CONCLUSION: From a biomechanical perspective, by resulting in more consistent outcomes under dynamic loading, standardized artificial stable pertrochanteric femur fracture creation may be more suitable for orthopaedic implant testing compared to osteotomizing the bone.

The effect of coronal splits on the structural stability of bi-condylar tibial plateau fractures: a biomechanical investigation.

INTRODUCTION: Surgical treatment of bi-condylar tibial plateau fractures is still challenging due to the complexity of the fracture and the difficult surgical approach. Coronal fracture lines are associated with a high risk of fixation failure. However, previous biomechanical studies and fracture classifications have disregarded coronal fracture lines. MATERIALS AND METHODS: This study aimed to develop a clinically relevant fracture model (Fracture C) and compare its mechanical behavior with the traditional Horwitz model (Fracture H). Twelve samples of fourth-generation tibia Sawbones were utilized to realize two fracture models with (Fracture C) or without (Fracture H) a coronal fracture line and both fixed with lateral locking plates. Loading of the tibial plateau was introduced through artificial femur condyles to cyclically load the fracture constructs until failure. Stiffness, fracture gap movements, failure loads as well as relative displacements and rotations of fracture fragments were measured. RESULTS: The presence of a coronal fracture line reduced fracture construct stiffness by 43% (p = 0.013) and decreased the failure load by 38% from 593 ± 159 to 368 ± 63 N (p = 0.016). Largest displacements were observed at the medial aspect between the tibial plateau and the tibial shaft in the longitudinal direction. Again, the presence of the coronal fracture line reduced the stability of the fragments and created increased joint incongruities. CONCLUSIONS: Coronal articular fracture lines substantially affect the mechanical response of tibia implant structures specifically on the medial side. With this in mind, utilizing a clinically relevant fracture model for biomechanical evaluations regarding bi-condylar tibial plateau fractures is strongly recommended.

Analyses of fracture line distribution in intra-articular distal radius fractures.

PURPOSE: To assess the association between the fracture line distribution and the location of comminution in intra-articular distal radius fractures by building fracture mapping. PATIENTS/METHODS: Forty cases with intra-articular fractures of distal radius were enrolled in the current prospective clinical study. Fracture lines and comminution zones were identified by reduced three-dimensional computed tomography reconstructions and then graphically superimposed onto a standard template to create two-dimensional fracture maps, followed by the conversion into heating maps. Based on qualitative descriptive fracture mapping analyses, the patterns of intra-articular distal radius fractures were determined. RESULTS: It was observed that the highest fracture line intensity was located as an inverted "T" shape zone in the dorsal aspect of the joint with high incidence of fractures and the prominently intense color in heat mapping. The keystone projected area, the radial styloid process and the metacarpal radial side articular surface were found to be the least involved parts of the fracture. According to the mapping of the number and distribution of fracture lines, a new classification method for intra-articular fractures of the distal radius was redefined. Different surgical approaches and internal fixation techniques were proposed for different types. In this paper, we retrospectively compared the preoperative X-ray findings between different types. Based on the preoperative X-ray prediction, the distal intra-articular radius fractures were classified, so as to develop effective surgical strategies. In this study, a new surgical approach was attempted, but due to the lack of evidence-based evidence, long-term postoperative complications and hand function should be further evaluated. CONCLUSION: This study redefines a new method for the classification of intra-articular fractures of the distal radius, which allows doctors to have a clearer understanding of the characteristics of distal radius fractures. Moreover, the application value in fracture diagnosis is more significant, and the best surgical approach is selected for different types.

The effect of teeth in mandibular fracture lines.

BACKGROUND/AIM: The decision to retain or extract teeth in the line of mandibular fractures has been a subject of debate in the scientific literature, and there is a need for further evidence to clear this issue. Thus, the aim of this study was to investigate the effects on healing of teeth in the line of mandibular fractures in order to contribute to the field. MATERIAL AND METHODS: The case notes of 100 patients with teeth in the line of 106 mandibular fractures were reviewed. Open reduction and rigid internal fixation (ORIF) was used if elastic intermaxillary reduction failed to achieve a satisfactory occlusion and/or anatomical reduction in the fragments as assessed by orthopantomogram (OPG) and clinical examination. The remaining cases had maxillomandibular fixation (MMF) with an arch bar and bridle wire. RESULTS: Three of the 106 teeth involved in the fracture lines healed with complications. In the cases where the teeth had been removed prior to fracture treatment, or in cases of delayed extractions, no complications were noted. CONCLUSION: The factors which should be considered for removal include the condition of the teeth and alveolar bone, the timing and the type of treatment. This decision should be made on an individual basis considering potential risks to avoid complications.

[Influence of anterior fracture line on anterior cortical reduction loss after cephalomedullary nail fixation in intertrochanteric fractures].

Objective: To investigate the position of the anterior fracture line in AO/Orthopaedic Trauma Association (AO/OTA) type A2 unstable intertrochanteric fractures and its impact on the incidence of anterior cortical reduction loss after cephalomedullary nail fixation. Methods: A clinical data of 95 patients with intertrochanteric fractures who met the selection criteria between April 2020 and February 2023 was retrospectively analyzed. All patients were treated with cephalomedullary nail fixation, and the intra- and post-operative imaging data were complete. Among them, there were 37 males and 58 females. The age ranged from 61 to 97 years, with an average of 79.6 years. The time from injury to operation ranged from 7 hours to 11 days, with an average of 2.8 days. According to the 2018-AO/OTA classification standard, there were 39 cases of type 31-A2.2 and 56 cases of type 31-A2.3. Intraoperative fluoroscopy was used to record the number of patients with satisfactory fracture alignment. The preoperative CT data were imported into Mimics17.0 software to simulate the fracture reduction and measure the distance between the anterior fracture line and the intertrochanteric line bony ridge. The fractures were classified as transcapsular fractures, extra-capsular fractures, and intra-capsular fractures according to the distance. CT three-dimensional reconstruction was performed within 2 weeks after operation to observe the number of patients with anterior cortical reduction loss. The postoperative anterior cortical reduction loss incidence in patients with satisfactory fracture alignment, and the relationship between postoperative anterior cortical reduction loss and the position of the anterior fracture line were observed. Results: There were 52 cases (54.7%) of transcapsular fractures, 24 cases (25.3%) of extra-capsular fractures, and 19 cases (20.0%) of intra-capsular fractures. Among them, 41 of the 52 transcapsular fractures had satisfactory fracture alignment, and 4 (9.8%) of them experienced anterior cortical reduction loss after operation; 19 of the 24 extra-capsular fractures had satisfactory fracture alignment, and no anterior cortical reduction loss occurred; 16 of the 19 intra-capsular fractures had satisfactory fracture alignment, and 7 (43.8%) of them experienced anterior cortical reduction loss after operation. There was a significant difference in the incidence of anterior cortical reduction loss between groups ( χ 2=8.538， P=0.003). All patients were followed up 3-26 months (mean, 9 months). Among them, 91 cases had fracture healing, and 4 cases had nonunion. Conclusion: In AO/OTA type A2 unstable intertrochanteric fractures, where the anterior fracture line is located within the joint capsule, there is a high risk of anterior cortical reduction loss after operation.

Intentional Replantation as a Viable Option for Crown-Root Fracture in Maxillary Central Incisor: A Case Report.

Crown-root fractures are often challenging to treat and have a poor prognosis. The present case explains the successful management of a vertically fractured tooth treated by intentional replantation in a 12-year-old child. The patient underwent a successful 12-month follow-up, which included a mobility test and measurement of the gingival sulcus depth. Additionally, a radiological assessment was performed to evaluate the root resorption, the integrity of the alveolar cortex, and the periodontal space. We suggest that intentional replantation may be an effective therapeutic approach for the treatment of cases of vertical crown-root fractures.

[Correlation between combined deflection angle classification adduction typing and complications after internal fixation of adduction femoral neck fracture].

Objective: To analyze the correlation between postoperative complications and combined deflection angle classification adduction type (CDAC-ADT) of femoral neck fractures after cannulated screw internal fixation. Methods: The clinical data of 121 patients with CDAC-ADT femoral neck fracture admitted between January 2018 and December 2021 and met the selected criteria were retrospectively analyzed. There were 69 males and 52 females, the age ranged from 19 to 79 years (mean, 48.1 years). The causes of injury included 52 cases of traffic accident, 24 cases of falling from height, and 45 cases of fall. The time from injury to operation ranged from 2 to 12 days, with an average of 6.0 days. Among them, there were 18 cases of CDAC-ADT type Ⅰ, 46 cases of type Ⅱ, and 57 cases of type Ⅲ; 6 cases of Garden type Ⅱ, 103 cases of type Ⅲ, and 12 cases of type Ⅳ; and according to the location of the fracture line, there were 26 cases of subcapitate type, 88 cases of transcervical type, and 7 cases of basal type. All patients were treated with cannulated screw internal fixation. The occurrence of complications (including internal fixation failure, fracture nonunion, and osteonecrosis of the femoral head) was recorded, and the correlation between complications and CDAC-ADT typing, Garden typing, and fracture line location were analyzed. Results: The patients were followed up 8-44 months, with a mean of 24.9 months. There were 10 cases of internal fixation failure, 7 cases of fracture nonunion, and 30 cases of osteonecrosis of the femoral head after operation. Correlation analysis showed that patients' CDAC-ADT typing was significantly correlated with the overall incidence of complication and the incidence of internal fixation failure, fracture nonunion, and osteonecrosis of the femoral head ( P<0.05), and the Pearson coefficient of contingency were 0.435, 0.251, 0.254, and 0.241, respectively. Garden typing did not correlate with the overall incidence of complication and the incidence of internal fixation failure and fracture nonunion ( P>0.05), but correlated with the incidence of osteonecrosis of the femoral head ( P<0.05), and the Pearson coefficient of contingency was 0.251. Fracture line position typing had no correlation with the overall incidence of complication and the incidence of internal fixation failure, fracture nonunion, and osteonecrosis of the femoral head ( P>0.05). Conclusion: CDAC-ADT typing has obvious correlation with postoperative complications of femoral neck fracture and can be used to predict complications of femoral neck fracture.

Accuracy of mapping results of thoracolumbar vertebral fracture verified using finite element analysis.

OBJECTIVE: To verify the results of three-dimensional fracture mapping of T12-L2 compression fractures by the finite element method from a biomechanical point of view, and to provide clinical reference. METHODS: This study is a retrospective study. By collecting 150 patients' computerized tomography (CT) data with thoracolumbar compression fractures (T12-L2) with AO type A. Mimics was used for three-dimensional (3D) reconstruction, and 3-Matic was used to mark fracture lines in stereo images. After standardized treatment, all fracture lines were drawn in the same 3D image, and finally fracture lines and fracture map were drawn. Constructing a 3D finite element model of thoracolumbar segment to verify the fracture thermogram results from the perspective of biomechanics. RESULTS: From the fracture map, fracture lines were mainly distributed in the upper part of the vertebral body, the leading edge of the anterior column (AC), and the lateral margin of the middle column (MC). In the finite element analysis, the stress mainly was concentrated on the edge of the anterior and middle column of the vertebral body and the upper part of the vertebral body, and the stress gradually decreased from the upper endplate to the endplate, and the stress was the least in the posterior column (PC) of the vertebral body. CONCLUSION: The results of finite element analysis further confirm the accuracy of fracture mapping and explain the distribution characteristics of fracture lines. This will provide theoretical support for the selection of clinical fracture treatment, intraoperative implants, and for a standard fracture model.

Assessment of Fracture Line Angle in Mallet Fractures.

Background: Surgery is often offered to patients with mallet fractures that have a large, displaced fragment and/or joint subluxation. However, the surgical approach remains a subject of debate, and surgery is frequently associated with unsatisfactory outcomes. We felt that the angle formed by the fracture line and the long axis of the distal phalanx on a lateral view radiograph (fracture line angle [FLA]) could be useful in determining the appropriate treatment strategy. The aim of this study was to assess the FLA and its distribution in mallet fractures. Methods: Three researchers measured the mallet FLA and the percentage of articular surface (PAS) involved in the lateral radiographs of 103 patients with a mallet fracture. Results: There was a strong correlation between the mallet FLA and the percentage of joint surface involvement between the three researchers. The mean FLA was 42.59° (±11.54) and it ranged from -1 to +1 standard deviation in 73 individuals (70.87%). The FLA varied over a wide range, while clustering near the average value. The average PAS involvement was 46.5% (±8.7%). There was no correlation between FLA and PAS involvement (p > 0.05). Conclusions: It is possible to quantify the mallet FLA accurately and consistently. It varies widely, regardless of the PAS involvement. When choosing the type of treatment and making prognostic predictions, the mallet FLA may be a helpful guide. Level of Evidence: Level IV (Diagnostic).

A study of fracture lines distribution characteristics in complete articular fractures of the patella.

Objective: The objective of this study was to unveil the characteristics of fracture lines distribution and explore its clinical significance of complete articular fractures of the patella. Methods: A consecutive series of image data from 88 patients with complete articular patella fractures were retrospectively included. Three-dimensional reconstruction images of the patella fractures were created and collected. Subsequently, these reconstructed images were visually overlaid onto a standard anterior and posterior patella template. The fracture lines were then identified, traced onto the template, and utilized to generate patella fracture maps. Furthermore, the incidence rate of patella fracture lines involving the distal pole was analyzed. Results: The maps depict the fracture lines of complete articular patella fractures. For simple and complex patella fractures, the primary fracture lines primarily converge within the Middle and Lower regions, exhibiting a transverse pattern. Conversely, the primary fracture lines in comminuted patella fractures are randomly dispersed across the patella. Examining the maps, approximately 63.6% (56/88) of complete articular patella fractures exhibited involvement of the distal pole in the anterior view, while 48.9% (43/88) displayed distal pole fractures in the posterior view. The incidence of distal pole injury increased progressively with the severity of patella fractures. Conclusion: The patterns and distribution of fracture lines in cases of complete articular patella fractures are prominently illustrated on the constructed fracture maps. Familiarity with these common characteristics of complete articular patella fracture, especially with the distal pole injury, can aid surgeons in developing preoperative planning, executing surgical strategies effectively, and reducing inappropriate treatment.

Three-dimensional computed tomography mapping techniques in the morphometric analysis of AO/OTA 33A and 33C distal femoral fractures: a retrospective single-center study.

Purpose: Complex distal femoral fractures involve a challenging set of considerations that must be known to provide optimal management. This study aimed to determine the location and frequency of fracture lines and comminution zones in AO/OTA types 33A and 33C distal femoral fractures using three-dimensional computed tomography mapping. Methods: Seventy-four consecutive eligible patients were included. Fracture fragments for each patient were reconstructed, virtually reduced, and adjusted to match the distal femoral template. Then, all fracture lines and comminuted areas were extracted in transparent mode, and corresponding heat maps were constructed. Finally, these maps, along with the quantitative analysis findings of the counts and volumes of each fragment, were used to summarize the characteristics of the fractures. Results: Thirty-four females and 40 males [average age, 58 years (range, 18-92 years)] presented with a distal femoral fracture. There were 53 AO/OTA type 33A fractures, and 21 AO/OTA type 33C fractures. These two patterns differed significantly on fracture fragment count, comminuted zone fracture fragment count, and mean comminuted zone fracture fragment volume (p < 0.05). Most of the fracture line heat zones were in the femoral epiphysis, intercondylar notch of the femur, and patellofemoral joint. The comminuted area heat regions were mostly found on the lateral, anterior, and posterior femoral diaphysis, with less involvement on the medial side. Conclusion: Our findings may serve as a guide for the surgical approach selection of complex distal femur fractures, the placement strategy of the internal fixation, and the optimization of the osteotomy plan for biomechanical studies.

Comparison of Dentin Microstructure and Its Correlation to the Direction of Fracture Line in Mandibular Molars of Young and Older Individuals: In Vitro Study.

INTRODUCTION: The aim of the study was to assess the presence and extent of sclerotic dentin and to study its impact on the direction of fracture lines in extracted mandibular first molars of young (20-44 years) and older age groups (45 and older). METHODS: Extracted permanent mandibular first molars were collected along with the related demographic details. A total of 40 teeth were included in this study, 20 each from young age group (YA group) (20-44 years) and older age group (OA group) (45-70 years). All molars were decoronated, and the sectioned mesial roots were embedded in acrylic blocks. They were subjected to vertical force in a universal testing machine. Fractured roots were then examined under the stereomicroscope at ×8 magnification to determine the direction and pattern of the fracture line. The roots were then sectioned and evaluated at ×10 and ×20 magnification to assess the dentin microstructure and its correlation with the direction of the fracture line. Statistical analysis was done by using χ2 test (P < .05). RESULTS: A greater incidence and degree of sclerotic dentin were found in the OA group as compared with the YA group, which was statistically significant. The sclerotic dentin was distributed predominantly mesiodistally and the fracture line propagated buccolingually in both young and older groups, which was statistically significant (P < .05). CONCLUSIONS: The presence of sclerotic dentin mesiodistally may impede crack propagation in this direction for both young and older age groups, causing the fracture line to extend buccolingually in coronal third of the root.

Effect of the lateral bone cut end on pattern of lingual split during bilateral sagittal split osteotomy in patients with skeletal class III malocclusion.

This study examines the effect of the lateral bone cut end (LBCE) on the pattern of lingual split during bilateral sagittal split osteotomy (BSSO) in patients with skeletal class III malocclusion. A case-control study according to the pattern of the sagittal split osteotomy (SSO) lingual split line was conducted in patients who underwent BSSO. The primary predictor variable was the ratio of the LBCE. The primary outcome variable was the type of lingual fracture line classified according to the lingual split scale (LSS). Other variables included patients' weight, sex, age, left and right sides of the mandible, and experience of the surgeon. Logistic regression analysis or the chi-squared test was performed to determine the effect of these variables on various types of lingual fracture line. The significance level was 95% (p < 0.05). There were 271 patients enrolled in this study. The SSO lingual split lines were divided into LSS1 (329/542), LSS2 (82/542), LSS3 (93/542), and LSS4 (38/542) splits. Logistic regression analysis showed that the LSS3 split was more likely to appear when the LBCE was closer to the lingual side (p = 0.0017). The age of patients significantly affected the possibilities of LSS2 (p = 0.0008) and LSS3 (p = 0.0023) splits. A LBCE close to the lingual side was an inducer for the formation of a LSS3 split in patients with skeletal class III malocclusion during BSSO. The age of the patient also affected the possibility of LSS2 and LSS3 splits.

Three-dimensional morphological study of type B lateral malleolar fractures with special reference to the end-tip location of proximal apexes.

Objective: We aimed to describe the morphological characteristics of Danis-Weber type B lateral malleolar fractures, with special attention given to the end-tip locations of fracture apexes, and to construct a 3D (three-dimensional) fracture line map. Methods: A total of 114 surgically treated cases of type B lateral malleolar fractures were retrospectively reviewed. The baseline data were collected, and computed tomography data were reconstructed in a 3D model. We measured the morphological characteristics and the end-tip location of the fracture apex on the 3D model. All the fracture lines were superimposed on a template fibula to generate a 3D fracture line map. Results: Among these 114 cases, 21 were isolated lateral malleolar fractures, 29 were bimalleolar fractures, and 64 were trimalleolar fractures. All the type B lateral malleolar fractures demonstrated a spiral or oblique fracture line. As measured from the distal tibial articular line, the fracture started at -6.22 ± 4.62 mm anteriorly and terminated at 27.23 ± 12.32 mm posteriorly, and the average fracture height was 33.45 ± 11.89 mm. The fracture line inclination angle was 56.85° ± 9.58°, and the total fracture spiral angle was 269.81° ± 37.09°, with fracture spikes of 156.20° ± 24.04°. The proximal end-tip location of the fracture apex was classified into four zones in the circumferential cortex: zone I (lateral ridge) in seven cases (6.1%), zone II (posterolateral surface) in 65 cases (57%), zone III (posterior ridge) in 39 cases (34.2%), and zone IV (medial surface) in three cases (2.6%). Altogether, 43% (49 cases) of fracture apexes were not distributed on the posterolateral surface of the fibula, as 34.2% (39 cases) were located on the posterior ridge (zone III). The aforementioned morphological parameters in fractures with zone III, sharp spikes, and further broken spikes were greater than those in zone II, blunt spikes, and fractures without further broken spikes. The 3D fracture map suggested that the fracture lines with the zone-III apex were steeper and longer than those with the zone-II apex. Conclusion: Nearly half of type B lateral malleolar fractures had their proximal end-tip of apexes not on the posterolateral surface, which may impair the mechanical application of antiglide plates. A steeper fracture line and longer fracture spike indicate a more posteromedial distribution of the fracture end-tip apex.