Anteromedial Cortex Research Articles

Relative instability ratios of bone wall defects in trochanteric hip fractures: A finite element analysis.

Background: For decades, medial and lateral wall fragments of trochanteric hip fractures were considered two pivotal factors that could influence the stability of postoperative femur-implant complex. However, most studies seemed to misunderstand the concept of the posteromedial fragment and equated it with the medial wall, which overlooked vital roles of the anteromedial wall. Roles of the posterior coronal bone fragment were also highlighted in some research. However, influences of the bone walls above the trochanteric fracture instability are yet to be investigated and quantified by means of finite element analysis. Methods: Eight trochanteric fracture fixation models with different wall defects were constructed. Outcome indicators were the von Mises stress of the implant models, the maximum/minimum principal strain, the risky tensile/compressive volume and the volume ratios of the bone models, the femoral head vertex displacement, and the fracture surface gap. Based on these indicator values, the relative instability ratios were computed. Results: Outcome indicators, absolute values, and nephograms of all models showed the same upward and concentrating trends with exerted hip contact loads shifting from static walking to dynamic climbing. Similarly, these indicators also exhibited the same trends when the eight models were solved in sequence. Moreover, the relative instability ratio of the medial wall (100%), particularly the anteromedial part (78.7%), was higher than the figure for the lateral wall (36.6%). Conclusion: The anteromedial wall played relatively pivotal stabilizing roles in trochanteric hip fractures compared with the posteromedial wall and the lateral wall, which indicated that orthopedic surgeons should attach more importance to the anteromedial cortex support in an operating theatre.

Proposal of a novel comprehensive classification for femoral intertrochanteric fractures

To introduce a novel comprehensive classification for femoral intertrochanteric fractures, and to accommodate the clinical requirement for the world-wide outbreak of geriatric hip fractures and surgical operations. On the basis of reviewing the history of classification of femoral intertrochanteric fractures and analyzing the advantages and disadvantages of AO/Orthopaedic Trauma Association (AO/OTA) classification in different periods, combined with the current situation of extensive preoperative CT scan and three-dimensional reconstruction and widespread use of intramedullary nail fixation in China, the "Elderly Hip Fracture" Research Group of the Reparative and Reconstructive Surgery Committee of the Chinese Rehabilitation Medical Association proposed a novel comprehensive classification for femoral intertrochanteric fractures, focusing on the structure of fracture stability reconstruction during internal fixation. The novel comprehensive classification of femoral intertrochanteric fractures incorporates multiple indicators of fracture classification, including the orientation of the fracture line, the degree of fracture fragmentation, the lesser trochanteric bone fragment and its distal extension length (>2 cm), the posterior coronal bone fragment and its anterior extension width (involving the lateral cortex of the head and neck implant entry point), transverse fracture of the lateral and anterior wall and its relationship with the implant entry point in the head and neck, and whether the cortex of the anteromedial inferior corner can be directly reduced to contact, etc. The femoral intertrochanteric fractures are divided into 4 types (type A1 is simple two-part fractures, type A2 is characterized by lesser trochanter fragment and posterior coronal fractures, type A3 is reverse obliquity and transverse fractures, type A4 is medial comminution which lacks anteromedial cortex transmission of compression force), each of which is subdivided into 4 subtypes and further subdivide into finer subgroups. In a review of 550 trochanteric hip fracture cases by three-dimensional CT, type A1 accounted for 20.0%, type A2 for 62.5%, type A3 for 15.5%, and type A4 for 2.0%, respectively. For subtypes, A2.2 is with a "banana-like" posterior coronal fragment, A2.4 is with distal cortex extension >2 cm of the lesser trochanter and anterior cortical expansion of the posterior coronal fragment to the entry portal of head-neck implants, A3.4 is a primary pantrochanteric fracture, and A4.4 is a concomitant ipsilateral segmental fracture of the neck and trochanter region. The novel comprehensive classification of femoral intertrochanteric fractures can describe the morphological characteristics of fractures in more detail, include more rare and complex types, provide more personalized subtype selection, and adapt to the clinical needs of both fractures and surgeries.

A sophisticated fracture classification system of the proximal femur trochanteric region (AO/OTA-31A) based on3D-CT images.

ObjectiveFracture classification evolves dynamically with new and enhanced imaging modalities. This paper aims to introduce a novel hypothesis of a sophisticated fracture classification system for the proximal femur trochanteric region (AO/OTA-31A) based on 3D-CT images and accommodate the clinical requirement of the worldwide outbreak of geriatric hip fractures with large amounts of surgical operations.MethodsIn the current practice of widely preoperative 3D-CT application and cephalomedullary nailing, we attempt to propose a new comprehensive classification system to describe the fracture characteristics in a more detailed and sophisticated architecture, and pay the most important concern to the parameters that contribute to fracture stability reconstruction in osteosynthesis.ResultsThe new four-by-four comprehensive classification system, followed the structure of the AO/OTA system, incorporates many fracture characteristics as dividing indexes into multiple grade levels, such as fracture line direction, the number of fragments, the lesser trochanter fragment and its distal extension (>2 cm), the posterior coronal fragment and its anterior expansion (to the entry portal of head–neck implant at the lateral cortex), the lateral wall and anterior cortex fracture, and the anteromedial inferior corner comminution. From a panoramic perspective, there are four types and each type has four subtypes. A1 is simple two-part fractures (20%), A2 is characterized by lesser trochanter fragment and posterior coronal fractures (62.5%), A3 is reverse obliquity and transverse fractures with complete lateral wall broken (15.5%), and A4 is medial wall comminution which further lacks anteromedial cortex transmission of compression force (2%). For subtypes, A2.2 is with a banana-like posterior coronal fragment, A2.4 is with distal cortex extension >2 cm of the lesser trochanter and anterior expansion of the posterior coronal fragment(s) to the entry portal of head–neck implants, A3.4 is a primary pantrochanteric fracture, and A4.4 is a concomitant ipsilateral segmental fracture of the neck and trochanter region.ConclusionClassification represents diversity under consistency. The four-by-four sophisticated classification system delineates fracture characteristics in more detail. It is applicable in the time of rapid outbreak of trochanteric fractures in the older population, the large amounts of surgical operations, and incorporates various rare and/or more complicated subtypes which is unclassifiable before.

Association between Immediate Postoperative Radiographic Findings and Failed Internal Fixation for Trochanteric Fractures: Systematic Review and Meta-Analysis.

Failed internal fixations for trochanteric fractures have a strong negative impact owing to increased postoperative mortality and high medical costs. However, evidence on the prognostic value of postoperative radiographic findings for failed internal fixations is limited. We aimed to clarify the association between comprehensive immediate postoperative radiographic findings and failed internal fixation using relative and absolute risk measures. We followed the meta-analysis of observational studies in epidemiology guidelines and the Cochrane handbook. We searched specific databases in November 2021. The outcomes of interest were failed internal fixation and cut-out. We pooled the odds ratios and 95% confidence intervals using a random-effects model and calculated the number needed to harm for each outcome. Thirty-six studies involving 8938 patients were included. The certainty of evidence in the association between postoperative radiographic findings and failed internal fixation or cut-out was mainly low or very low except for the association between intramedullary malreduction on the anteromedial cortex and failed internal fixation. Moderate certainty of evidence supported that intramedullary malreduction on the anteromedial cortex was associated with failed internal fixation. Most postoperative radiographic findings on immediate postoperative radiographs for trochanteric fractures were uncertain as prognostic factors for failed internal fixations.

Posterior hip fracture-dislocation associated with posterior wall fracture of the acetabulum and ipsilateral comminuted trochanteric fracture of the femur: A case report.

Introduction and importanceTraumatic posterior dislocation of the hip is often associated with fractures of the femoral head and posterior wall of the acetabulum. However, hip fracture-dislocation that includes the posterior wall of the acetabulum and the ipsilateral femoral trochanter is rare. There is no consensus on the bone that should be operated on first, the operative position, and the choice of implant for femoral fixation.Case presentationA 67-year-old man was brought to our emergency department after a 2-m fall. He was diagnosed with a hip fracture-dislocation associated with posterior wall acetabular fracture and ipsilateral femoral trochanteric fracture. Surgical reconstruction was performed with intramedullary nail (IMN) fixation of the femoral trochanteric lesion, followed by anatomically rigid acetabular fixation in the lateral decubitus position. At the 5-year follow-up after the injury, the patient showed good objective and subjective clinical outcomes.Clinical discussionFixing the femur first could allow an easier reduction and traction. The lateral decubitus position was useful, because fixation of the femur and the acetabulum could be performed without changing the position. When fixing the femoral trochanteric lesion, attention was paid to reduce the anteromedial cortex of the proximal fragment extramedullarly to the distal fragment to prevent complications such as cutout and implant breakage.ConclusionAnatomically rigid fixation of the posterior wall of the acetabulum secondary to IMN fixation of the femur, with anteromedial cortical support in the lateral decubitus position, could achieve good objective and subjective clinical outcomes.

Calcar fracture gapping: a reliable predictor of anteromedial cortical support failure after cephalomedullary nailing for pertrochanteric femur fractures

BackgroundMaintaining anteromedial cortical support is essential for controlling sliding and decreasing postoperative implant-related complications. However, adequate fracture reduction with cortical support in immediate postoperative fluoroscopy is not invariable in postoperative follow-ups. This study was conducted to investigate the risk factors leading to anteromedial cortical support failure in follow up for pertrochanteric femur fractures treated with cephalomedullary nails.MethodsThis retrospective study enrolled 159 patients with pertrochanteric fractures (AO/OTA- 31A1 and 31A2) that fixed with cephalomedullary nails. All patients were evaluated as adequate fracture reduction in immediate postoperative fluoroscopy before leaving the operation theater. The patients were separated into two groups based on the condition of the anteromedial cortex in the postoperative 3D CT with full-range observation: those with calcar support maintained in Group 1 and those with calcar support lost in Group 2. Demographic information, fracture classification, TAD (tip-apex distance), Cal-TAD, Parker ratio, NSA (neck-shaft angle), reduction quality score, and calcar fracture gapping were collected and compared. Logistic regression analysis was conducted to explore the risk factors leading to anteromedial cortex change.ResultsAnteromedial cortical support failure was noted in 46 cases (29%). There was no significant difference between the two groups concerning age, sex, side injury, TAD, Cal-TAD, Parker ratio, or NSA. There was a significant difference in the AO/OTA fracture classification in univariate analysis but no difference in the multivariable analysis. The reduction quality score, calcar fracture gapping in the AP (anteroposterior), and lateral views were significantly associated with anteromedial cortical support failure in follow-up after cephalomedullary nailing in the multivariable analysis. The threshold value of calcar fracture gapping for the risk of loss was 4.2 mm in the AP and 3.8 mm in the lateral fluoroscopies. Mechanical complications (lateral sliding and varus) were frequently observed in the negative anteromedial cortical support group.ConclusionsGood reduction quality was a protective factor, and larger calcar fracture gapping in the AP and lateral views were risk factors leading to the postoperative loss of anteromedial cortical support. Therefore, we should pay close attention to fracture reduction and minimize the calcar fracture gap during surgery.

Low filling ratio of the distal nail segment to the medullary canal is a risk factor for loss of anteromedial cortical support: a case control study

BackgroundAnteromedial cortical support apposition (positive and/or neutral cortical relations) is crucial for surgical stability reconstruction in the treatment of trochanteric femur fractures. However, the loss of fracture reduction is frequent in follow-ups after cephalomedullary nail fixation. This paper aimed to investigate the possible predictive risk factors for postoperative loss of anteromedial cortex buttress after nail fixation.MethodsA retrospective analysis of 122 patients with AO/OTA 31A1 and A2 trochanteric femur fractures treated with cephalomedullary nails between January 2017 and December 2019 was performed. The patients were classified into two groups according to the postoperative status of the anteromedial cortical apposition in 3D CT images: Group 1 with contact “yes” (positive or anatomic) and Group 2 with contact “No” (negative, loss of contact). The fracture reduction quality score, tip-apex distance (TAD), calcar-referenced TAD (Cal-TAD), Parker ratio, neck-shaft angle (NSA), and the filling ratio of the distal nail segment to medullary canal diameter in anteroposterior (AP) and lateral fluoroscopies (taken immediately after the operation) were examined in univariate and multivariate analyses. Mechanical complications were measured and compared in follow-up radiographs.ResultsAccording to the postoperative 3D CT, 84 individuals (69%) were categorized into Group 1, and 38 individuals (31%) were classified as Group 2. The multivariate logistic regression analysis showed that the poor fracture reduction quality score (P < 0.001) and decreasing filling ratio in the lateral view (P < 0.001) were significant risk factors for the loss of anteromedial cortical contact. The threshold value for the distal nail filling ratio in lateral fluoroscopy predicting fracture reduction re-displacement was found to be 53%, with 89.3% sensitivity and 78.9% specificity. The mechanical complication (varus and over lateral sliding) rate was higher in Group 2.ConclusionsThe fracture reduction quality score and the decreasing filling ratio of the distal nail to the medullary canal in the lateral view (a novel parameter causing pendulum-like movement of the nail) were possible risk factors for postoperative loss of anteromedial cortical support.

Postoperative computed tomography assessment of anteromedial cortex reduction is a predictor for reoperation after intramedullary nail fixation for pertrochanteric fractures.

Postoperative radiographs are routinely used to assess fracture reduction following intramedullary nail fixation for pertrochanteric fractures, even though computed tomography (CT) is a superior modality. We aimed to determine the association between reduction quality assessed by CT and rates of reoperation and to evaluate the association of reoperation and reduction quality according to the assessment modality (plain radiographs vs. CT). A retrospective analysis of 299 consecutive patients treated with intramedullary nail fixation for pertrochanteric fractures was conducted. Fracture reduction measured by postoperative radiographs and CT was categorized as anatomical type, extramedullary type, or intramedullary type. Postoperative data for analysis included reduction status,tip-apex distance(TAD), screw position in the femoral head, sliding distance, and conditions associated with reoperation. Of the 299 patients included with a mean age of 83.1 ± 8.2years, there were six patients who required reoperation (2.0%). According to the CT assessments, there were 42 intramedullary reductions (14.0%). Patients with a non-intramedullary reduction based on postoperative CT images were significantly more likely to have proper placement of the screw, a reduced TAD, a reduced sliding distance, and a lower reoperation rate than those with an intramedullary reduction (P < 0.05). The reduction quality assessed by postoperative CT was significantly associated with reoperation (95% CI, 1.45-29.31). Intramedullary reduction assessed by CT was associated with reoperation. The reduction quality based on CT findings was more predictive for reoperation than that from plain radiographs.

Arthroscopic Primary Repair of Proximal Anterior Cruciate Ligament Tears With Suture Augmentation

Background: Historically, the midterm outcomes of open anterior cruciate ligament (ACL) repair were rather disappointing, and ACL reconstruction subsequently became the surgical standard for ACL injuries. Recent studies, however, have shown that there might be a role for arthroscopic primary repair in appropriately selected patients with proximal ACL tears. Indications: Due to more prominent blood supply in the proximal ligament region, ACL repair should only be performed in patients with proximal tears and good-to-excellent tissue quality. Although all patients are potential candidates, this procedure is preferably performed acutely and in adult patients. Technique Description: First, it is identified whether a proximal tear with good tissue quality is present. Then, both ACL bundles are sutured individually from distal to proximal using a Bunnell-type pattern and a self-retrieving suture passer. The posterolateral bundle is then reattached first in anatomical fashion, using a 4.75-mm vented biocomposite suture anchor. Next, the suture anchor of the anteromedial bundle is preloaded with an internal suture tape augmentation. After anchor deployment, the suture tape augmentation is channeled through a small 2.5-mm tibial tunnel in the anterior third of the tibial ACL footprint. Finally, the suture augmentation is tensioned near full extension and fixed to the tibia’s anteromedial cortex using single suture anchor fixation. Results: Recently, we have published a series of the first 113 consecutive repair patients with minimum 2-year follow-up, of which 60 received additional suture augmentation. In this cohort, the overall failure rate was 13%, which was similar to 3 other studies on modern-day ACL repair (range: 5%-15%). Subgroup analysis showed that the failure rate was much higher in patients ≤21 years (38%) but low in patients &gt;21 years (0%). Finally, it has been shown that there is an earlier return of knee motion, complications are rare, and there is less joint awareness after ACL repair as compared with ACL reconstruction. Conclusion: Selective, modern-day, arthroscopic primary ACL repair with suture augmentation seems to be a good alternative to ACL reconstruction in carefully selected patients, which include patients with proximal tears and good tissue quality and aged ≥22 years.

The Modulatory Role of Cortisol in the Regulation of Sexual Behavior in Young Males

The proneness to be sexually aroused, to perform sexual acts, or to be sexually disinhibited during a particular mood varies across individuals. However, the physiological mechanisms underlying this specific and variable relationship between mood and sex-related processes are poorly understood. We propose that cortisol may act as an important moderator in this as it has shown to influence sexual arousal and to play a neuromodulatory role during emotion regulation. Here, we conducted a functional magnetic resonance imaging study in a sample of young males to investigate whether cortisol modulates the neural response during the approach of sexual stimuli in an approach-avoidance task and whether this potential relationship explains the individual differences in sexual inhibition and in mood-related sexual interest and activity. We revealed that cortisol associates with the anteromedial prefrontal cortex activation during the approach towards sexual stimuli. Moreover, this anteromedial prefrontal cortex response was dependent on individual differences in sexual inhibition and the improvements of negative mood as a result of sexual activity. The anteromedial prefrontal cortex is already known to process bottom-up information, reward, and risk estimation. The neuromodulatory role of cortisol within this region during sexual approach may represent a previously unknown yet key element in the regulation of sexual behavior in young males.

A new fluoroscopic view for evaluation of anteromedial cortex reduction quality during cephalomedullary nailing for intertrochanteric femur fractures: the 30\xb0 oblique tangential projection

BackgroundAnteromedial cortex-to-cortex reduction is a key parameter for stable reconstruction of the fracture fragments during the intertrochanteric fracture fixation. This paper introduces the oblique fluoroscopic projection as a novel method to evaluate the quality of anteromedial cortical apposition.MethodsThree proximal femur specimens were marked with steel wires along five anatomic landmarks: Greater trochanter, Lesser trochanter, Intertrochanteric line, Anterolateral tubercle and the Anteromedial cortical line. After obtaining the standard femoral neck AP and lateral fluoroscopic images, the C-arm was rotated by every 5°increments until a clear tangential view of the antero-medial-inferior corner cortex was observed. 98 cases of intertrochanteric hip fractures were enrolled from April 2018 to October 2019. After fixation with the nails, the intra-operative anteromedial cortex reduction quality was evaluated from the AP, the true lateral, and the new anteromedial oblique fluoroscopic images. The fluoroscopic results were compared with the post-operative 3D-CT reconstruction images.ResultsThe specimen study showed that internal rotation of the C-arm to approximately 30 ° can remove all the obscure shadows and clearly display the antero-medial-inferior cortical tangent line. Clinically,the positive, neutral and negative apposition of different cortices via intra-operative fluoroscopic images showed79, 19 and 0 cases of medial cortical apposition in AP views; 2, 68 and 28 cases of anterior cortices in lateral views;and 22, 51 and 25cases of anteromedial cortical apposition in oblique views respectively. The post-operative 3D-CT reconstruction images revealed that the final anteromedial cortical contact was noted in 62 cases (63.3%), and lost in 36 cases (36.7%). The overall coincidence rate between intra-operative fluoroscopy and post-operative 3D-CT was 63.3% (62/98) in AP view,79.6% (78/98) in lateral view, and 86.7% (85/98) in oblique view(p < 0.001). Negative cortical apposition in oblique view was highly predictive of a final loss of cortical support on 3D CT (24/25 cases, 96%).And non-negative cortical apposition in oblique view was highly associated with true cortical support on 3D CT images (61/73 cases, 83.6%) (p < 0.001).ConclusionsBesides the AP and lateral projections, an anteromedial oblique view of 30° certifies to be a very useful means for evaluation of the fracture reduction quality of anteromedial cortical apposition.

Anatomical tibial component is related to more medial tibial stress shielding after total knee arthroplasty in Korean patients.

This study aimed to investigate stress shielding of anatomical tibial components (ATCs) in comparison to conventional symmetric tibial components (STCs) in Korean patients which may be related to medial tibial bone loss. 78 knees in 59 patients with ATCs (Persona™) and 74 knees in 58 patients with STCs (NexGen LPS-Flex™) were retrospectively reviewed. Radiographic parameters and clinical outcomes in both groups were compared. Logistic regression analysis was performed to identify risk factors for medial tibial bone loss. Medial tibial bone loss was significantly greater in the ATC group (1.6 ± 1.3mm) than in the STC group (0.4 ± 0.8mm) (p < 0.001). The ATC group showed a shorter distance between the distal metal tip and anteromedial cortex and higher invading into the sclerotic bone lesion (ISBL) than the STC group (p = 0.034 and p = 0.044, respectively). Multiple logistic regression analysis suggested ATC, a shorter distance to the anteromedial cortex, and the presence of ISBL as risk factors for medial tibial bone loss. The odds ratios of medial tibial bone loss according to type of prosthesis, distance to anteromedial cortex, and presence of ISBL were 6.25 (range 2.86-13.63, p < 0.001), 0.69 (range 0.51-0.93, p = 0.015), and 3.79 (range 1.56-9.21, p = 0.003), respectively. Notwithstanding, there was no difference in clinical outcomes between the two groups. In Korean patients, ATCs potentially causes greater medial tibial bone loss due to stress shielding than STCs. The design, however, does not yet appear to affect clinical outcomes at mid-term follow-up. Retrospective cohort study, level III.

Three-Dimensional Mapping of Medial Wall in Unstable Pertrochanteric Fractures.

Objective Unstable pertrochanteric fractures are usually treated with internal fixation, and the integrity of the anteromedial cortex is an important factor for stability and healing. In this study, we described and analyzed the three-dimensional mapping technology and morphological characteristics of pertrochanteric fractures. Methods Fifty-nine pertrochanteric fractures (OTA/AO 2007 types 31A2) were retrospectively reviewed. Computed tomographic (CT) images for all fractures were superimposed on a standard template. Medial wall integrity was analyzed, and three-dimensional fracture maps were created. Results Pertrochanteric fractures always have a posterior defect in the medial cortex. The mean width of the defect, in our study, was 21.5 mm (SD: 6.1 mm, range: 10–40 mm), 56.3% (SD: 13.7%, range: 27.5-100%). Bone segments that contact by the anteromedial cortex were 16.5 mm (SD: 5.3 mm, range: 0-29 mm). Conclusion The integrity of the anteromedial cortex should be considered during internal fixation of femoral trochanteric fractures. These morphological characteristics could be used to form postoperative cortical contact and improve stability of the fixation. Three-dimensional mapping technology can help establish a typical fracture model, thereby improving doctors' understanding of fracture characteristics.

Intraoperative assessment of reduction quality during nail fixation of intertrochanteric fractures

BackgroundThe quality of intertrochanteric fracture reduction has traditionally been evaluated using simple radiographs. However, subjective intraoperative evaluation and efforts to achieve a perfect reduction are essential for optimal outcomes. This study aimed to establish criteria for the intraoperative assessment of the quality of intertrochanteric fracture reduction and also analyzed postoperative outcomes in terms of reduction quality. MethodsThis study included 106 patients who received cephalo-medullary nailing for the treatment of intertrochanteric fractures between March 2012 and May 2016 and were followed-up for at least 1 year. An image intensifier was used intraoperatively to evaluate reduction quality by examining the restoration of anteromedial cortex continuity, and neck-shaft angle and anteversion. Based on the reduction quality, the patients were classified into optimal, acceptable, and unacceptable groups, with intervention provided for the unacceptable group. The need for revision surgery and the degree of blade sliding were assessed, and postoperative outcomes related to implant position were analyzed. ResultsOver 50% of patients with Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) type 31A2 and A3 fractures were assigned to the unacceptable group after closed reduction (P = 0.006), and 60 cases required additional reduction. Approximately 40% of cases classified as clinically unacceptable required revision, and the rate of sliding was ≥2-fold higher in the unacceptable group than those in the optimal and acceptable groups (P = 0.015), with an average excessive sliding of 9.85 mm. Regarding implant position, cut-out or penetration were observed in cases with superiorly-located blades (P = 0.039). ConclusionsGood outcomes cannot be achieved with traction alone for femoral intertrochanteric fractures. Active management is required because accurate anteromedial cortex reduction, and restoration of neck-shaft angle and anteversion are essential in femoral intertrochanteric fractures.

Concept evolution and research progress of stability reconstruction for intertrochanteric fracture

To summarize the evolving concept and research progress on stability reconstruction in the surgical treatment of intertrochanteric fracture. Related literature and author's own experience concerning the surgical treatment of intertrochanteric fracture were reviewed and analyzed in terms of fracture pathoanatomy, stable and unstable pattern, adequate and in-adequate reduction, primary and secondary stability, postoperative stability evaluation, and early weight-bearing. Intertrochanteric fracture occur at the translational area of cervico-trochanteric junction, which has a nature tendency to varus instability. Fracture reduction quality is the paramount factor and is evaluated by two views, the anteroposterior and lateral Garden alignment and cortex apposition between the head-neck fragment and the femoral shaft. Rather than the posteromedial lesser trochanteric frag ment, the cortical support concept (positive, neutral, negative) emphasizes the reduction of anteromedial cortex to a nonanatomic positive apposition or an "anatomic" neutral apposition in intraoperative fluoroscopy. Postoperative radiographic stability score provides a quantitative assessment for early weight-bearing standing and walking. However, some fractures may lose cortical contact and buttress (negative) during the process of postoperative telescoping and secondary stability. Further studies are needed to elucidate the risk factors such as tilting, swing or rotation of the head-neck fragment, and propose new preventive methods. Stability reconstruction of intertrochanteric fracture requires adequate fracture reduction with Garden alignment and anteromedial cortical support apposition, and reliable sustainment by internal fixation implants. Early weight-bearing standing and walking is safe in patients with perfect postoperative stability score.

The measurement and clinical significance of the rotation angles of head-neck fragments after cephalomedullary nail fixation in intertrochanteric fractures

To measure the rotation angle of the head-neck fragment of intertrochanteric fracture after cephalomedullary nail fixation by three-dimensional CT imaging, and to explore its clinical significance. The clinical data of 68 patients with unstable intertrochanteric fracture of AO/Orthopaedic Trauma Association (AO-OTA) type 31-A2 treated with cephalomedullary nail fixation and with complete intraoperative fluoroscopy and postoperative three-dimensional CT imaging data between July 2016 and October 2018 were retrospectively analyzed. Among them, there were 21 males and 47 females, aged 68-93 years, with an average age of 81.8 years. There were 31 cases of AO/OTA type 31-A2.2 and 37 cases of 31-A2.3. Fracture reduction quality was evaluated according to Baumgaertner et al. and Chang et al. criteria. The anteromedial cortical contact or not of each patient was observed by three-dimensional CT imaging on T3DView software after operation. The rotation of head-neck fragments were divided into three types: non-rotation, flexion rotation, and hyperextension rotation. The rotation angles of each type were measured and the relationship between the rotation type of the head-neck fragments and the contact of the anteromedial cortex was analyzed. The reduction and fixation of the small trochanter were not performed in 68 patients. According to Baumgaertner et al. criteria, the quality of fracture reduction was excellent in 15 cases (22.1%), acceptable in 50 cases (73.5%), and poor in 3 cases (4.4%). According to Chang et al. criteria, 31 cases were excellent (45.6%), 33 cases were acceptable (48.5%), and 4 cases were poor (5.9%). Thirty-nine cases (57.4%) received anteromedial cortical support and 29 cases (42.6%) did not receive cortical support. Three-dimensional CT imaging showed non-rotation in 12 cases (17.6%), flexion rotation in 39 cases (57.4%), and hyperextension rotation in 17 cases (25.0%). There were 7 cases (58.3%), 30 cases (76.9%), and 2 cases (11.8%) of cortical support in non-rotation group, flexion rotation group, and hyperextension rotation group, respectively. The rotation angles were (1.05±0.61), (13.96±6.17), (8.21±3.88)°, respectively. There were significant differences between groups ( P<0.05). In the unstable intertrochanteric fracture after cephalomedullary nail fixation, the rotation of head-neck fragment exists in most patients, and the types of flexion rotation and non-rotation can easily obtain cortical support reduction.

Phosphaturic Mesenchymal Heel Tumor Presenting with Tumor-Induced Osteomalacia

To help clinicians identify and treat patients with tumor-induced osteomalacia (TIO) resulting from a phosphaturic mesenchymal tumor, mixed connective tissue variant (PMTMCT). Describe the history, presentation, laboratory findings, diagnostic studies, treatment, and literature review. A 58-year-old female with no significant past medical history presents with ongoing multiple bone pain for years. She had a bone scan showing multiple focal areas of increased uptake involving bilateral ribs, distal right tibia, and left femoral neck, representing previously healed fractures. Her bilateral lower-extremity magnetic resonance imaging showed stress fractures of the anteromedial cortex, right tibia, and the left femoral neck. Phosphorus was noted to be 1.9 mg/dL (normal range, 2.0 to 4.0 mg/dL), and alkaline phosphatase was 179 U/L (normal range, 25 to 110 U/L). Tubular maximum re-absorption of phosphate to glomerular filtration rate ratio was 0.438, which was low. An outside physician initiated patient on teriparatide, which showed bone mineral density improvement after 1 year, and then the teriparatide was stopped. Later, she developed a nontraumatic pubic ramus fracture; teriparatide was resumed. While on teriparatide, she developed several new rib fractures. Due to declining phosphorus levels, further investigation led to an elevated fibroblast growth factor 23 (FGF-23) level of 243 RU/mL (normal, <50 RU/mL). TIO was strongly suspected, and a nuclear medicine positron emission tomography/computed tomography trunk with 68Ga-1,4,7,10-tetraazacyclododecane 1,4,7,10-tetraacetic acid tyrosine-3-octreotate (i.e., 68Ga-DOTATATE) showed a right heel soft-tissue nodule. Fine-needle aspiration biopsy was performed, confirming PMTMCT, positive for FGF-23 mRNA. After surgery, her symptoms resolved and her phosphorus normalized. TIO is a rare paraneoplastic syndrome characterized by bone pain, muscle weakness, and fractures associated with persistent hypophosphatemia. Clinicians now have new imaging tools to help identify and treat patients with PMTMCT.

Effect of reduction quality on post-operative outcomes in 31-A2 intertrochanteric fractures following intramedullary fixation: a retrospective study based on computerised tomography\xa0 findings

PurposeTo determine how the reduction of medial and anteromedial cortices using CT findings in 31-A2 intertrochanteric fractures treated with the intramedullary nail could affect the clinical outcomes and complication rates of the fractures.MethodsWe retrospectively analyzed the data of 43 patients with 31-A2 intertrochanteric fractures who underwent closed reduction and intramedullary internal fixation (CRIF) between January 2010 and December 2013. Patients were classified into two groups based on the post-operative CT scans taken from the sagittal and coronal planes, respectively. Five radiographic parameters and three clinical parameters were used to evaluate the post-operative functional states and mobilization levels in this study. Post-operative complications were also recorded.ResultsThe mean loss of the femoral neck-shaft angle (FNSA) was significantly smaller in Group C1 than that in Group C2. There were significant differences in the sliding distance of the cephalic nail and the loss of femoral head height between the two groups. In terms of the reduction conditions shown on the sagittal planes, the FNSA, sliding distance of the cephalic nail, and the loss of FHH were significantly different, although differences in TCD were not significant. Patients in groups C1 (3.6%) and S1 (0.0%) had lower complication rates compared to patients in groups C2 (26.7%) and S2 (27.8%).ConclusionPatients with good reduction quality of the medial and anteromedial sustainable cortices had better clinical outcomes and lower complication rates. The sustainable stability and anti-rotational function of these validated reductions might play a critical role in maintaining the fragment positions and reducing the incidence of complications in patients.

ID 61 – Electrophysiological correlates of experimental pain perception

Objective Identify pain markers remains a major scientific and medical problem. In this view, we studied the dynamics of central and autonomic responses to tonic painful stimuli. Methods Twelve healthy subjects underwent 2 tonic painful (hand electrical stimulations and 10°C water immersion) and 2 non-painful (hand 15 °C water immersion and stressful cognitive) tests during 2 min. Continuous 128 electroencephalographic (EEG) derivations, pupillary, electrodermal conductance, heart rate and blood pressure were recorded, with pain ratings. Time–frequency analyses were applied to EEG and autonomic measures. Loreta® and BESA were used to estimate the location of EEG activities. Results A significant contralateral decrease in alpha power occurred in parietal-central regions during the 2 painful but not in non-painful conditions, with involvement of somatosensory, dorsolateral and anteromedial prefrontal cortices. Electrodermal conductance and pupil dilation showed large and reproducible variations during painful and stressful non-painful conditions, while cardiovascular responses were only responsive to the latter. Conclusions These results suggest a specific electrophysiological response to experimental pain, based on the combination of EEG-alpha power decrease with electrodermal and pupil autonomic responses. Key message This work highlighted a combination of non-invasive pain markers that may be tested in various clinical settings to detect pain in non-communicative patients.

A study of biplanar crossed pin construct in the management of displaced pediatric supracondylar humeral fractures.

PurposeStudy of a biplanar crossed pin construct by two crossed Kirschner wires in the management of displaced extension type supracondylar humeral fractures in children.MethodsSixty-four patients with such fractures were included and treated according to the study protocol: after achieving closed reduction under general anesthesia with fluoroscopic control, two crossed Kirschner wires of equal diameter were inserted percutaneously. The first lateral wire tracts from the posterolateral corner of the epicondyle to the anteromedial cortex proximally. Then, the medial wire is inserted from the anteromedial corner of the epicondyle to the posterolateral cortex proximally after crossing the fracture site. Thus, a biplanar crossed pin construct was achieved, as each wire had two separate fixation points and the crossed construct was achieved not only in the coronal plane but also in the sagittal plane. Every effort was made to get this construct right at the very first attempt without repetition.ResultsTwo patients were lost to follow-up during the first postoperative year. The mean follow-up for the remaining 62 patients was 14.5 months (range 6–24 months). At the final follow-up, using Flynn’s overall modified classification, the clinical result was considered to be satisfactory in 60 (96.8 %) patients and unsatisfactory with poor result in two (3.2 %) patients. Technical error was thought to be the cause of the poor results. There were no postoperative neural or vascular complications.ConclusionA biplanar crossed pin construct achieved by two Kirschner wires crossed in the coronal and sagittal planes is efficient to stabilize a displaced extension type supracondylar fracture of the humerus in children.