Effect of coaching the sit-to-stand motion and attentional focus.

[Purpose] The present study investigated whether (1) "standing up while bowing" is effective for promoting the sit-to-stand (STS) motion and (2) whether this coaching promotes internal focus. [Participants and Methods] The participants included 17 healthy adults who performed the 30-s chair stand test with two sets of verbal instructions. The verbal instructions were as follows: "Please stand up as many times as possible for 30 s" (control condition) and "Please stand up while bowing as many times as possible for 30 s" (bowing condition). The participants performed the tests successively under the two conditions. In the 30-s chair stand test, a three-axis accelerometer was attached to the participants and the sagittal STS motion was filmed using a video camera. After the 30-s chair stand test, we used the modified Movement-Specific Reinvestment Scale (MSRS) to evaluate attentional focus. Differences in the measurements were analyzed using the Wilcoxon signed-rank test or paired t-test for each condition. [Results] Statistical analysis revealed significant differences in the CS-30 count, time from sitting to standing, time from sitting to lift-off, time from lift-off to standing, and the trunk tilt angle on lift-off. Regarding the questionnaire, Statistical analysis revealed significant differences in the MSRS and "conscious motor processing". [Conclusion] These results suggest that "standing up while bowing" has limited effectiveness in promoting the STS motion because the coaching promotes internal focus.

How infants predict respect-based power.

Research has shown that infants represent legitimate leadership and predict continued obedience to authority, but which cues they use to do so remains unknown. Across eight pre-registered experiments varying the cue provided, we tested if Norwegian 21-month-olds (N=128) expected three protagonists to obey a character even in her absence. We assessed whether bowing for the character, receiving a tribute from or conferring a benefit to the protagonists, imposing a cost on them (forcefully taking a resource or hitting them), or relative physical size were used as cues to generate the expectation of continued obedience that marks legitimate leadership. Whereas bowing sufficed in generating such an expectation, we found positive Bayesian evidence that all the other cues did not. Norwegian infants unlikely have witnessed bowing in their everyday life. Hence, bowing/prostration as cue for continued obedience may form part of an early-developing capacity to represent leadership built by evolution.

Endoscopic Distance and its Impact on Quantified Age-related Vocal Fold Atrophy Measures.

INTRODUCTION: The bowing index (BI) and normalized glottal gap area (NGGA) are used to quantify vocal fold morphology in ARVA; however, the influence of the distance between the flexible laryngoscope lens and the target area is not known. The goal is to test whether the endoscopic distance impacts vocal fold morphology measurements in patients with ARVA during flexible video laryngostroboscopy (VLS). METHOD: Patients with ARVA who underwent VLS were included. Images were classified into near (close to the petiole of the epiglottis) and far (below nasopharynx, with tongue base and entire epiglottis visible) conditions. BI was calculated using a mobile application, and NGGA was measured using ImageJ. RESULTS: This study included 23 patients; the mean age was 77 ± 7 years. Mean BI measured at the near distance was higher than far distances with a mean difference of 1.94 (95% CI: 0.92-2.96, p = 0.001). NGGA showed difference with changed distance -0.24 (95% CI: -0.48 to 0.01, p < 0.05).When stratifying patients into two groups based on median BI measurement, there was a statistically significant difference between near and far conditions, with increased BI in the near condition for patients above the median (p < 0.05), but no difference between the near and far condition for patients with BI below the median. CONCLUSION: The BI and NGGA were impacted by the endoscopic distance during flexible VLS. BI was significantly higher in the near condition compared with the far condition. The difference in BI between the near and far conditions was more pronounced when the vocal fold bowing was greater. These findings call for heightened awareness of measurement discrepancies secondary to the endoscopic distance during flexible laryngostroboscopy. LEVEL OF EVIDENCE: Level 2 Laryngoscope, 2024.

Real-Time Visual Feedback Based on MIMUs Technology Reduces Bowing Errors in Beginner Violin Students.

Violin is one of the most complex musical instruments to learn. The learning process requires constant training and many hours of exercise and is primarily based on a student-teacher interaction where the latter guides the beginner through verbal instructions, visual demonstrations, and physical guidance. The teacher's instruction and practice allow the student to learn gradually how to perform the correct gesture autonomously. Unfortunately, these traditional teaching methods require the constant supervision of a teacher and the interpretation of non-real-time feedback provided after the performance. To address these limitations, this work presents a novel interface (Visual Interface for Bowing Evaluation-VIBE) to facilitate student's progression throughout the learning process, even in the absence of direct teacher intervention. The proposed interface allows two key parameters of bowing movements to be monitored, namely, the angle between the bow and the string (i.e., α angle) and the bow tilt (i.e., ß angle), providing real-time visual feedback on how to correctly move the bow. Results collected on 24 beginners (12 exposed to visual feedback, 12 in a control group) showed a positive effect of the real-time visual feedback on the improvement of bow control. Moreover, the subjects exposed to visual feedback judged the latter as useful to correct their movement and clear in terms of the presentation of data. Although the task was rated as harder when performed with the additional feedback, the subjects did not perceive the presence of a violin teacher as essential to interpret the feedback.

Ulnar Bowing and Distal Radioulnar Joint Anatomy: A Three-Dimensional, In Situ Clinical Assessment.

Purpose: Distal radioulnar joint (DRUJ) injuries can be devastating and challenging to manage. The multiplanar curvature exhibited by the ulna impacts the morphology of the DRUJ, making it difficult to assess through two-dimensional radiographs alone. We used full-length, three-dimensional (3D) computed tomography angiography scans to assess the relationship between ulnar bowing, DRUJ ulnar variance (UV), and sigmoid notch angle. The goal of this study was to establish normal anatomic ranges for these landmarks to improve treatment for forearm traumas and DRUJ pathologies. Methods: Eighty-two intact upper extremity computed tomography angiography scans were examined and reconstructed into 3D models. We characterized ulnar bowing and DRUJ metrics using computer-aided design software. Measures of central tendency and Pearson correlation coefficients were calculated for comparative analysis. Results: The study yielded an average ulnar length of 272.3 mm. We identified the proximal ulnar bow at 36.7% of the bone's total length, possessing a depth of 10.3 mm, a proximal angle of 6.6°, and a distal angle of 3.9°. The distal ulnar bow appeared at 75.3% of the bone's length, characterized by a depth of 4.2 mm, a proximal angle of 2°, and a distal angle of 4.3°. In the coronal plane, the proximal angle of the proximal ulnar bow correlated positively with UV (r = 0.39, P < .001), whereas the distal angle of the distal ulnar bow correlated negatively (r = -0.48, P < .001). We also found significant correlations between the depths of both proximal and distal bows with UV (r = 0.38, P < .001; r = -0.34, P < .001, respectively). Moreover, UV within the DRUJ strongly correlated with the sigmoid notch angle (r = -0.77, P = .01). In contrast, the sagittal plane metrics did not show meaningful correlations with UV. Conclusion: Sagittal alignment and translation at the DRUJ articulation are directly related to ulna bowing at the distal ulna. A nuanced understanding of these 3D relationships can enhance preoperative planning when correcting ulnar-side pathology. Type of study/level of evidence: Therapeutic IV.

Lengthening in congenital posteromedial bowing of tibia: a follow-up series at skeletal maturity.

PURPOSE: Congenital posteromedial bowing (CPMB) of tibia is a rare, usually self-resolving condition that is present at birth. The data on the long-term outcome of lengthening, choice of fixator, outcome in early and late age groups, and complications is sparse, hence the need for this study. METHODS: This retrospective study included 93 patients with 94 affected legs from 1991 to 2023. The patients were categorized into early (under 10 years) and late (10 years or above) intervention groups. Eighteen patients with nineteen lengthening episodes who attained skeletal maturity made the basis of this study and will be discussed in detail. RESULTS: The outcome for the lengthening group at maturity was satisfactory, with 5.53 cm of average length gained per lengthening episode, a mean LLD of 0.31 cm at final follow-up, a mean age of 23.63 years (range 14-38 years), and an average follow-up of 12.51 years (range 3-28 years) post-lengthening, but the procedure was associated with difficulties like ankle stiffness, tibial valgus, pin tract infections, and fractures through regenerate. CONCLUSION: This study represents a large single-centre series on CPMB. We recommend that surgery for lengthening should be done at an older age, close to skeletal maturity, wherever possible to reduce the risk of repeat lengthening procedures. Based on our experience, we recommend the use of a circular fixator. Uniplanar distractors should have an adequate number and spread of Schanz screws in each segment to reduce the risk of valgus malalignment of distracting segments of bone.

Endoscopic third ventriculostomy in hydrocephalus patients with functioning ventriculoperitoneal shunts: challenging the dictum that shunts treat all types of hydrocephalus. Patient series.

BACKGROUND: Although ventriculoperitoneal shunting is standard for hydrocephalus, shunting may not be ideal for aqueductal stenosis. A cohort of patients with aqueductal stenosis displayed symptoms of over- and underdrainage, despite a patent ventriculoperitoneal shunt (VPS) and optimized valve settings. Endoscopic third ventriculostomies (ETVs) were performed in a subset of these patients with successful treatment of their underlying hydrocephalus, despite a functioning shunt. OBSERVATIONS: All patients who had undergone ETV with a history of ventriculoperitoneal shunting were retrospectively reviewed. Patients experiencing over- or underdrainage symptoms despite a patent shunt were included. Cerebral aqueduct anatomy and third ventricle bowing were reviewed on preoperative imaging. Seven patients met the study criteria. All showed cerebral aqueductal stenosis and third ventricle bowing. After ETV, all patients demonstrated decreased third ventricle bowing and clinical improvement without the need for secondary cerebrospinal fluid (CSF) diversion. LESSONS: Despite a functioning VPS, patients with aqueductal stenosis may not be adequately treated. The underlying reasons are not clearly understood but suggest abnormal CSF dynamics due to aberrant parenchymal compliance. The authors theorize that ETV can more effectively treat these patients. ETV can be considered a viable treatment option in aqueductal stenosis despite a patent VPS, challenging the traditional teaching that shunts ideally treat all types of hydrocephalus.

Combined Predictive Model for Endoscopic Third Ventriculostomy Success in Adults and Children.

BACKGROUND: The selection of patients in whom endoscopic third ventriculostomy (ETV) can be effective remains poorly defined. The ETV success score (ETVSS) and the presence of bowing of the third ventricle have been identified as independent factors for predicting success, each with limitations. The objective of this study is to elaborate a combined predictive model to predict ETV success in a mixed cohort of patients. METHODS: Demographic, intraoperative, postoperative, and radiologic variables were analyzed in all ventriculostomies performed consecutively at a single institution from December 2004 to December 2022. Qualitative and quantitative measurements of preoperative, immediate, and late postoperative magnetic resonance imaging were conducted. Univariate analysis and logistic regression models were performed. RESULTS: 118 ETVs were performed in the selected period. Of these procedures, 106 met the inclusion criteria. The overall success rate was 71.7%, with a median follow-up of 3.64 years (interquartile range, 1.06-5.62). The median age was 36.1 years (interquartile range, 11.7-53.5). 35.84% were children (median, 7.81 years). Among the 80 patients with third ventricle bowing, the success rate was 88.8% (P < 0.001). Larger third ventricle dimensions on preoperative mid-sagittal magnetic resonance imaging were associated with increased ETV success. The model with the best receiver operating characteristic curves, with an area under the curve of 0.918 (95% confidence interval, 0.856-0.979) includes sex, ETVSS, presence of complications, and third ventricle bowing. CONCLUSIONS: The presence of bowing of the third ventricle is strongly associated with a higher ETV success rate. However, a combined predictive model that integrates it with the ETVSS is the most appropriate approach for selecting patients for ETV.

Correction of anterior bowing complicating tibial osteofibrous dysplasia in preadolescents by osteotomy and telescopic nailing without lesional resection: a preliminary study of four-case reports.

BACKGROUND: Osteofibrous dysplasia (OFD) occurs most frequently in the tibia and may result in deformity and pathological fracture. Surgical treatment such as curettage or segment excision has been performed but remains controversial due to high complication rates and surgical burden. This study introduces a new method to manage OFD with anterior bowing of the tibia using minimally invasive tibial osteotomy and telescopic rod (TR) osteosynthesis without extensive lesion resection. METHODS: A retrospective study of 4 children with OFD and tibia bowing deformity treated with minimally invasive tibial wedge osteotomy and TR fixation between January 2015 and November 2020 was performed. Results including bone healing, complications, function based on MSTS score, and recurrance of deformity were assessed. RESULTS: The median follow-up was 29 months. Radiographs showed the median time for union was 3 months. There were no instances of refracture or recurrence of deformity. The mean post-operative MSTS score was significantly higher than preoperative score. CONCLUSIONS: This method avoids large bone defects and reconstructive procedures. It is an effective and minimally invasive approach for managing anterior bowing deformity secondary to OFD while improving function and quality of life. LEVEL OF EVIDENCE: Level IV; Case Series; Treatment Study.

The main cause of tibial prosthesis malalignment after total knee arthroplasty in Southern Chinese population.

Objectives: This study aimed to determine the occurrence rate of malalignment of tibial prosthesis and explore the influencing factors. Methods: 296 patients from Southern China who underwent total knee arthroplasty (TKA) were selected as the research objects. Their general demographic data were recorded. The tibial bowing angle (TBA), tibial length, medial proximal tibial angle (MPTA), tibial plateau shift angle (TPSA), tibial bone loss, lateral distal tibial angle, and overall width of tibial plateau and widths of medial and lateral tibial plateau were measured before TKA. The tibial component coronal alignment angle (TCCA) was measured after the operation. Malalignment of the tibial prosthesis was defined as TCCA <87° or TCCA >93°. Tibial bowing was indicated by TBA >2°, and lateral bowing was recorded as +. The correlations of TCCA with demographic data and pre-operation imaging measurement parameters were statistically analyzed. Results: Bivariate correlation analysis revealed negative correlations between TCCA and TBA (r = -0.602, P < 0.001) and TPSA (r = -0.304, P < 0.001), and a positive correlation with MPTA (r = -0.318, P < 0.001). Multivariate linear regression analysis demonstrated a significant negative correlation between TCCA and TBA (P < 0.001). The occurrence rate of malalignment of tibial prosthesis was 12.37 %. The occurrence rates of malalignment were 22.54 % in the tibial bowing group and 6.87 % in the non-tibial bowing group, showing statistical differences (P < 0.001). Conclusion: The malalignment rate of tibial prosthesis among Southern Chinese patients is relatively high, possibly attributed to the tibial anatomy anomalies, particularly the tibial bowing. The entry point should be determined based on tibial morphology.

Ultrasound and magnetic resonance imaging neurography assessment of diagnostic criteria in patients with carpal tunnel syndrome using electrophysiological tests as gold standard: A prospective study.

Objectives: Evaluating peripheral neuropathy mainly relies on physical examination, patient history, and electrophysiological studies. High-resolution ultrasound is a fast, noninvasive modality for dynamic nerve assessment that enables the length of the nerve to be examined. Magnetic resonance imaging is preferred for examining deeper nerves with a high contrast resolution; its use shows excellent benefit in patients with atypical presentation, equivocal diagnosis, suspected secondary causes, and postsurgical relapse. We aimed to assess the measurements and criteria for both ultrasound and magnetic resonance neurography for the diagnosis of carpal tunnel syndrome, based mainly on the three measurements assessed by Buchberger et al. Methods: This prospective study was conducted to test diagnostic accuracy. Thirty-two patients who presented clinically with, and were diagnosed by electrophysiological tests as having, carpal tunnel syndrome participated. Superficial ultrasound of the wrist joint was performed on all participants, followed by magnetic resonance imaging within 1 week of ultrasonography. Results: The three main parameters of cross-sectional area measurement, distal nerve flattening, and flexor retinaculum bowing indices showed positive occurrences of 93.7%, 59.4%, and 59.4%, respectively; 90.6% of patients had decreased nerve echotexture. The diagnostic ability of magnetic resonance imaging was decreased when cross-sectional area measurements were used: positive results were achieved in 81.2% of patients, but the positive results showing the distal tunnel nerve increased flattening and bowed flexor retinaculum slightly decreased to 56.2% for each. A high T2 signal of the median nerve was observed in 90.6% of patients. In an agreement analysis, we found a statistically significant difference that supported the use of ultrasound as a primary diagnostic modality for carpal tunnel syndrome. However, magnetic resonance imaging improved tissue characterization and was a good diagnostic modality, with a statistically significant difference, for cases of secondary carpal tunnel syndrome, detection of the underlying entrapping cause, and early abnormality detection in the innervated muscle. Conclusions: Our results demonstrate that ultrasound examination can be used as the first imaging modality after physician evaluation, with results comparable to those of electrophysiological studies for evaluating carpal tunnel syndrome and determining its cause. Magnetic resonance neurography examination is the second step in detecting secondary causes in cases with suspected early muscle denervation changes that cannot be elicited by ultrasound or in cases with equivocal results.

Associations between femoral 3D curvature and sagittal imbalance of spine.

Background: The sagittal imbalance (SI) of spine triggers compensatory mechanisms (CMs) of lower extremity (LE) to restore trunk balance. These CMs can cause long-period stress on the femur and may possibly alter the femoral morphology. This cross-sectional observational study aimed to answer the following questions: (a) Do SI subjects exhibit greater femoral bowing compared to subjects with sagittal balance? (b) Are there associations between femoral bowing and CMs of LE in SI subjects? Methods: Subjects who underwent biplanar full body radiographs with the EOS imaging system between January 2016 and September 2021 were recruited. Sagittal parameters included T1-pelvic angle (TPA), pelvic incidence (PI), pelvic tilt (PT), sacral slope, lumbar lordosis (LL), PI-LL, and PT/PI ratio. LE parameters were femoral obliquity angle (FOA), knee flexion angle (KA), and ankle dorsiflexion angle. Femoral bowing was quantified as 3D radius of femoral curvature (RFC). Associations between 3D RFC and the radiographic parameters were analyzed. Results: A total of 105 subjects were included, classified into balance group (TPA < 14°, n = 40), SI group (TPA ≥ 14° and KA <5°, n = 30), and SI with knee flexion group (TPA ≥ 14° and KA ≥ 5°, n = 35). 3D RFC was significantly lower in SI with knee flexion group compared to the other two groups (both p < 0.001). Stepwise linear regression showed that age, SI and knee flexion, femoral length (FL), FOA, and KA were independent predictors for 3D RFC. Conclusion: Greater femoral bowing is observed in subjects with SI and knee flexion compared to the balanced population. CM parameters, including KA and FOA, are associated with 3D RFC. Further longitudinal study is needed to investigate the cause-and-effect relationship between SI, CMs of LE, and femoral bowing.

Cough and Swallowing Therapy and Their Effects on Vocal Fold Bowing and Laryngeal Lesions.

OBJECTIVE: Expiratory muscle strength training (EMST) and sensorimotor training of airway protection (smTAP) are two exercises intended to improve cough and swallowing in people with Parkinson's Disease (PwPD). The aims of this study were to (1) examine whether EMST or smTAP elicit changes to vocal fold bowing; and (2) describe the safety of EMST and smTAP as it relates to the development of vocal fold lesions. METHOD(S): This was a secondary analysis of data from PwPD who completed EMST or smTAP as part of a prospective randomized controlled trial. Vocal fold bowing (BI) and the presence of laryngeal lesions were blindly analyzed from flexible endoscopic evaluation of swallowing (FEES) using ImageJ software and operational definitions. Linear regression was used to examine the influence time (pre- vs. post-therapy) and therapy (EMST vs. smTAP) on vocal fold bowing. Descriptive statistics were used to describe the presence of laryngeal lesions. RESULT(S): Overall, 56 participants were included, 28 per group. The median BI scores pre- and post-therapy were 8.2% and 8.3% for the EMST group and 11.3% and 8.4% for the smTAP group, respectively. Statistical analyses revealed insufficient evidence to suggest an effect of time and treatment type on BI (p > 0.05) or on the presence of vocal fold lesions (p > 0.05). CONCLUSION: Based on these and previous findings, it appears that changes in vocal fold bowing do not drive treatment effects following EMST and smTAP. Also, this study further supports the safety of smTAP and EMST despite the required forceful exhalation and repetitive coughing. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:1127-1132, 2024.

Quantitative Evaluation of Vocal Bowing Following Bilateral Thyroplasty in Age-Related Vocal Atrophy.

OBJECTIVE: Age-related vocal atrophy (ARVA) is associated with vocal fold bowing, persistent glottal gap during phonation, and dysphonia. Bilateral medialization thyroplasty is sometimes performed in patients with ARVA to improve vocal fold closure and voice. We set out to quantify stroboscopic changes in vocal fold bowing, glottal closure, and abduction angle following bilateral thyroplasty and determine how these changes affect voice quality among patients with ARVA. METHODS: Fifteen individuals with ARVA who underwent bilateral medialization thyroplasty were included in this study. Two independent investigators calculated bowing index (BI), normalized glottal gap area (NGGA), and maximum abduction angle from laryngostroboscopic exams using ImageJ™. Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) and patient-reported measures were collected before and after thyroplasty. RESULTS: Thyroplasty resulted in a 10-point improvement in overall CAPE-V (Mean dif -10; 95% CI -17, -3.3, p < 0.01) and VHI-10 (mean dif -3.8; 95% CI -9.8, 2.3, p = 0.19, n = 8). NGGA and BI significantly decreased following surgery (mean dif -78; 95% CI -155, -1.5, p = 0.05; and mean dif -2.1; 95% CI -2.4, -0.84, p < 0.01, respectively). BI correlated with CAPE-V scores (r = 0.66, 95% CI 0.22, 0.87, p < 0.01). When considering the normalized combined contributions of both NGGA and BI, there was a stronger correlation in CAPE-V scores (r = 0.87, 95% CI 0.50, 0.97, p < 0.01) compared with either measure alone. CONCLUSIONS: Thyroplasty resulted in a decrease in vocal fold bowing, glottal gap area, and CAPE-V scores in patients with ARVA. Correction of vocal bowing and glottal gap, following bilateral thyroplasty, improved voice measures following surgery. Quantitative evaluation of vocal fold morphology may be valuable when assessing the severity and treatment-response in patients with ARVA following bilateral thyroplasty. Laryngoscope, 134:835-841, 2024.

Chronological Changes in Sagittal Femoral Bowing after Primary Cementless Total Hip Arthroplasty: A Comparative 3D CT Study.

Little is known about dynamic changes of femoral anatomy after total hip arthroplasty (THA), in particular about sagittal femoral bowing (SFB). A 3D CT study was designed to evaluate the chronological changes of SFB after cementless femoral stem implantation for primary THA. Ten patients who underwent unilateral primary THA with a cementless femoral stem, with 2 consecutive CT scans (extending from the fourth lumbar vertebra to the tibial plateaus), performed before THA and at least 3 years after THA, were enrolled. The 3D models of femurs were created using image segmentation software. Using the two CT scans, SFB values of the proximal and middle thirds were calculated on the replaced and untreated sides by two different observers. Eight anatomical stems and two conical stems were involved. The post-operative CT was performed at an average follow-up of 6.5 years after THA (range: 3-12.5). The measurements performed by the two observers did not differ in the proximal and middle regions. A significant difference between the pre-operative and post-operative SFB compared to the untreated side was found in the proximal femur segment (p = 0.004). Use of a cementless stem in THA induced chronological changes in SFB of the proximal femur, after a minimum timespan of 3 years.

Correlation between Femoral Neck Version, Sagittal Femoral Bowing Angle and Sagittal Offset of the Femoral Head from the Distal Femur Axis in an Osteological Collection.

Aim: Radiographic analysis of lower limb alignment is crucial for the planning and evaluation of deformity correction. Assessment in the sagittal plane is often overlooked compared with the coronal plane for a variety of reasons. We aimed to investigate the relationship between the femoral head in the sagittal plane and femoral neck version in the axial plane, and how sagittal femoral bowing angle (sFBA) may contribute. Materials and methods: Twenty-five each of high (1-2 standard deviations above mean), normal (2.5° below to 2.5° above the mean), and low (1-2 standard deviations below the mean) version femurs were randomly selected from an osteological collection database, photographed and measured for sFBA and sagittal offset of femoral head from the distal femur axis. Lines were drawn within the proximal and distal quartiles of the shaft to create sFBA. The offset of the distal quartile line and the femoral head was also measured. High intra- and inter-observer correlations were established. The relationship between parameters was assessed using the Pearson coefficient (r). Results: Sagittal offset of the femoral head from the distal femur axis was found to be highly correlated with sFBA (r = 0.78), and only mildly with femoral neck version (r = 0.52). Sagittal femoral bowing angle and femoral neck version share no relationship (r = 0.05). Conclusions: Neither the sFBA nor sagittal femoral head offset is strongly associated with femoral neck version. Clinical significance: Our data reinforce the need for long leg lateral films to include the femoral head in sagittal deformity analysis, as imaging limited to the knee will not account for the effect of bowing on femoral head position. How to cite this article: Ho D, Liu RW, Mcclure PK. Correlation between Femoral Neck Version, Sagittal Femoral Bowing Angle and Sagittal Offset of the Femoral Head from the Distal Femur Axis in an Osteological Collection. Strategies Trauma Limb Reconstr 2023;18(1):12-15.

Femoral Bowing Increases Early Postoperative Stress around the Femoral Stem in Humans: A Finite Element Analysis.

Background: This study aimed to clarify the characteristics of stress distribution caused by the placement of tapered wedge stems in bowed femurs compared with that in normal femurs and the effect of varus stem placement. Methods: Models with normal and enhanced bowing were created from the right-side computed tomography data of a 17-year-old woman with the least bowing among 40 participants who underwent anterior cruciate ligament reconstruction or operative treatment for trauma in our hospital between January 2017 and May 2018. Finite element analysis was performed, assuming the tapered wedge stem was placed in the neutral and varus positions. Results: Varus stem placement on a femur with normal bowing showed a deviation and increase of von Mises stresses in the medial femur. Stem placement on a bowed femur, even when placed in the neutral position, increased stress across the periprosthetic bone. When the stem was placed in the varus position, von Mises stress across the periprosthetic bone increased. Zone 7, with strong bowing, demonstrated 3.6-fold increased stress compared with normal femurs. The maximum tensile principal stress was greatest in zone 6 and increased in zones 3 and 4. Conclusions: Surgeons should assess femoral bowing preoperatively and pay particular attention to intraoperative stem alignment for femurs with high bowing.

How Do the Morphological Abnormalities of Femoral Head and Neck, Femoral Shaft and Femoral Condyle Affect the Occurrence and Development of Medial Knee Osteoarthritis.

OBJECTIVE: At present, the main viewpoint is that tibial varus is the main reason of medial knee osteoarthritis (OA), and high tibial osteotomy (HTO) is also the main alignment correction method to correct medial knee OA. In contrast, the impact of the anatomical alignment of the femur on medial knee OA is often overlooked. We evaluated the increased risk for medial knee OA because a varus alignment could be attributed to the anatomical reasons that include hip anatomy, femoral shaft bowing (FSB) and femoral condylar dysplasia. METHODS: The present research adopted a cross-sectional study method. We selected 62 patients with HTO in the Third Hospital of Hebei Medical University from June 2021 to March 2022 as the HTO group and 55 healthy volunteers as the control group. Femoral neck-shaft angle (NSA), lateral FSB, mechanical lateral distal femoral angle (mLDFA) and hip-knee-ankle (HKA) was radiographically examined within the two groups. The femoral neck length and offset were also measured, and the ratio is represented by the ratio of the femoral neck length to off-set (N/O). The 2-tailed Student t-test was used to compare the differences between groups when the data were in accordance with a normal distribution. Otherwise, the Mann-Whitney U tests was used to compare the differences between groups. RESULT: Compared to the control group, the HTO group had a higher offset (p < 0.05), greater femoral neck length (p < 0.05), and decreased (more varus) NSA (p < 0.05). The HKA in the HTO group was 172.20 ° (3.50°), which was significantly lower than that of the control group 177.00° (3.05°), (p < 0.001), while the medial OA was associated with more varus HKA. The mean mLDFA was 89.10 ° (2.35°) and 87.50° (2.85°) in the HTO and control groups (p < 0.005), respectively. The mean lateral FSB values of the full-length radiographs were larger (p < 0.001) in the HTO group (4.24° ± 3.25°) than that in control group (1.16° ± 2.32°). CONCLUSION: The reduction of NSA (coxa vara) and the increase of the mLDFA can lead to medial knee OA, while the lateral FSB also affects medial OA. We believe that femoral deformity is also one of the cause of the medial knee OA. Therefore, it is necessary to evaluate the joint deformity of the femur and tibia before surgery in order to determine whether to use HTO alone to correct the lower limb alignment.

Frequency and pathogenesis of periprosthetic atypical femoral fractures associated with total knee arthroplasty: A multicenter prospective study with complementary histopathological and biomechanical analysis.

INTRODUCTION: Although the diagnostic criteria for atypical femoral fracture (AFF) exclude periprosthetic fractures, reports of periprosthetic femoral fractures with characteristics of AFF are rapidly increasing. In this study, we investigated the frequency and pathogenesis of periprosthetic AFF associated with total knee arthroplasty (TKA) based on a theory of AFF subtypes that divides AFFs into two main types: fragility stress fractures of the bowed femoral shaft in the mid-shaft and "typical" subtrochanteric AFFs due to suppression of bone turnover (e.g., by bisphosphonates). PATIENTS AND METHODS: This multicenter prospective study of AFFs was conducted from 2015 through 2022. Clinical, pathological, and morphological characteristics were investigated in patients with periprosthetic AFFs associated only with non-stem TKA. Then, biomechanical investigation of the periprosthetic AFF was performed by computer tomography-based finite element analysis (CT/FEA) using two models with different load axes to examine how the correction of lower limb alignment by TKA influences the tensile stress distribution of the femur and the location of the AFF. RESULTS: Four of 61 AFFs (6.6%) were identified to be periprosthetic AFF (1 mid-shaft; 3 subtrochanteric). Periprosthetic AFFs had characteristics including mechanical stress due to bowing deformity and potentially suppressed bone turnover due to long-term exposure to specific drugs (e.g., bisphosphonates and glucocorticoids). Although 2 periprosthetic AFFs appeared to involve a bowed femur, one with both of the aforementioned characteristics occurred in the subtrochanteric region, which would be an unusual site for a bowed AFF, and it was demonstrated histologically to have biological activity at the fracture site, suggesting a stress fracture. Furthermore, CT/FEA revealed that tensile stress distribution changed proximally as load axis was shifted laterally according to correction of lower limb alignment by TKA. CONCLUSION: Orthopedic surgeons should recognize the presence of TKA-associated periprosthetic AFF caused by various factors including specific drugs, bowing deformity, and lower limb alignment. X-rays of the full-length femurs should be checked regularly after TKA, especially in patients with bowed femurs or long-term exposure to specific drugs.

Surgical strategy of the treatment of atypical femoral fractures.

The atypical femoral fracture (AFF) has been attracting significant attention because of its increasing incidence; additionally, its treatment is challenging from biological and mechanical aspects. Although surgery is often required to manage complete AFFs, clear guidelines for the surgical treatment of AFFs are currently sparse. We reviewed and described the surgical treatment of AFFs and the surveillance of the contralateral femur. For complete AFFs, cephalomedullary intramedullary nailing spanning the entire length of the femur can be used. Various surgical techniques to overcome the femoral bowing common in AFFs include a lateral entry point, external rotation of the nail, and the use of a nail with a small radius of curvature, or a contralateral nail. In the case of a narrow medullary canal, severe femoral bowing, or pre-existing implants, plate fixation may be considered as an alternative. For incomplete AFFs, prophylactic fixation depends on several risk factors, such as a subtrochanteric location, presence of a radiolucent line, functional pain, and condition of the contralateral femur; the same surgical principles as those in complete AFFs can be applied. Finally, once AFF is diagnosed, clinicians should recognize the increased risk of contralateral AFFs, and close surveillance of the contralateral femur is recommended.