Race and Gender Differences in Anterior Cruciate Ligament Femoral Footprint Location and Orientation: A 3D-MRI Study.

OBJECTIVE: The femoral tunnel position is crucial to anatomic single-bundle anterior cruciate ligament (ACL) reconstruction, but the ideal femoral footprint position are mostly based on small-sized cadaveric studies and elderly patients with a single ethnic background. This study aimed to identify potential race- or gender-specific differences in the ACL femoral footprint location and ACL orientation, determine the correlation between the ACL orientation and the femoral footprint location. METHODS: Magnetic resonance images (MRIs) of 90 Caucasian participants and 90 matched Chinese subjects were used for reconstruction of three-dimensional (3D) femur and tibial models. ACL footprints were sketched by several experienced orthopedic surgeons on the MRI photographs. The anatomical coordinate system was applied to reflect the ACL footprint location and orientation of scanned samples. The femoral ACL footprint locations were represented by their distance from the origin in the anteroposterior (A/P) and distal-proximal (D/P) directions. The orientation of the ACL was described with the sagittal, coronal and transverse deviation angles. The ACL orientation and femoral footprint position were compared by the two-sided t-test. Multiple regression analysis was used to study the correlation between the orientation and femoral footprint position. RESULTS: The average femur footprint A/P position was -6.6 ± 1.6 mm in the Chinese group and -5.1 ± 2.3 mm in the Caucasian group, (p < 0.001). The average femur footprint D/P position was -2.8 ± 2.4 mm in Chinese and - 3.9 ± 2.0 mm in Caucasians, (p = 0.001). The Chinese group had a mean difference of a 1.5 mm (6.1%) more posterior and 1.1 mm (5.3%) more proximal in the position from the flexion-extension axis (FEA). And the males have a sagittal plane elevation about 4-5° higher than females in both racial groups. Furthermore, for every 1% (0.40 mm) increase in A/P and D/P values, the sagittal angle decreased by about 0.12° and 0.24°, respectively; the coronal angle decreased by about 0.10° and 0.30°, respectively. For every 1% (0.40 mm) increase in D/P value, the transverse angle increased by about 0.14°. CONCLUSION: The significant race- and gender-specific differences in the femoral footprint and orientation of the ACL should be taken in consideration during anatomic single-bundle ACL reconstruction. Furthermore, the quantitative relationship between the ACL orientation and the footprint location might provide some reference for surgeons to develop a surgical strategy in ACL single-bundle reconstruction and revision.

Relationships between position of patellar ridge high point and morphology of resected surface for patellar resurfacing in total knee arthroplasty.

Background: Reproducing the native patellar ridge high point while maximizing osseous coverage is important for the success of patellar replacement, but it cannot always be achieved simultaneously. This study aimed to thoroughly investigate the relationships and their influencing factors between the positions of the high point of patellar ridge (HPPR) and the morphology of the patellar resected surface. Methods: Four hundred seventy-three patients (265 men, 208 women) aged 18 to 50 years with knee injuries before arthroscopy were retrospectively collected for this cross-sectional study. Computed tomography (CT) and magnetic resonance imaging (MRI) were used to construct 3D computer models of the patella and patellar cartilage. The morphometric characteristics of the patellar cut after virtual resection and the HPPR position relative to the patellar cut centre were measured and analyzed. Results: The medial displacements of the HPPR were positively correlated with Wiberg's classification and index (all P<0.001). The mean values of HPPR's medial displacements were 0.15 of the medial width of patellar cut, and 93.2% of all patella ranged from 0 to 0.3. When the implant's apex were placed at 0.15 of the medial width of patellar cut medialized, the proportion of implant placement errors within 1 mm of the native high point was 12% more in female patella (P=0.01), and 7% more in all patella (P=0.03) than 3 mm medialized. Conclusions: Wiberg's system can roughly predicted the medial-lateral position of the HPPR. The HPPR was mainly medially located at the 0.15 of the medial patellar width approximately, and 15% medialized of the implant's apex can better reproduce the native patellar high point than 3 mm medialized. The current results provide basic data for patellar implant selection, preoperative planning, and implant design to reproduce the native patellar high point better while maximizing osseous coverage for patellar resurfacing.

Significant race and gender differences in anterior cruciate ligament tibial footprint location: a 3D-based analysis.

BACKGROUND: The aim of the present study was to identify potential race- or gender-specific differences in anterior cruciate ligament (ACL) tibial footprint location from the tibia anatomical coordinate system (tACS) origin, investigate the distances from the tibial footprint to the anterior root of the lateral meniscus (ARLM) and the medial tibial spine (MTS), determine how reliable the ARLM and MTS can be in locating the ACL tibial footprint, and assess the risk of iatrogenic ARLM injuries caused by using reamers with various diameters (7-10 mm). PATIENTS AND METHODS: Magnetic resonance images of 91 Chinese and 91 Caucasian subjects were used for the reconstruction of three-dimensional (3D) tibial and ACL tibial footprint models. The anatomical coordinate system was applied to reflect the anatomical locations of scanned samples. RESULTS: The average anteroposterior (A/P) tibial footprint location was 17.1 ± 2.3 mm and 20.0 ± 3.4 mm in Chinese and Caucasians, respectively (P < .001). The average mediolateral (M/L) tibial footprint location was 34.2 ± 2.4 mm and 37.4 ± 3.6 mm in Chinese and Caucasians, respectively (P < .001). The average difference between men and women was 2 mm in Chinese and 3.1 mm in Caucasians. The safe zone for tibial tunnel reaming to avoid ARLM injury was 2.2 mm and 1.9 mm away from the central tibial footprint in the Chinese and Caucasians, respectively. The probability of damaging the ARLM by using reamers with various diameters ranged from 0% for Chinese males with a 7 mm reamer to 30% in Caucasian females with a 10 mm reamer. CONCLUSIONS: The significant race- and gender-specific differences in the ACL tibial footprint should be taken in consideration during anatomic ACL reconstruction. The ARLM and MTS are reliable intraoperative landmarks for identifying the tibial ACL footprint. Caucasians and females might be more prone to iatrogenic ARLM injury. LEVEL OF EVIDENCE: III, cohort study. TRIAL REGISTRATION: This study has been approved by the ethical research committee of the General Hospital of Southern Theater Command of PLA under the code: [2019] No.10.

Loaded open-kinetic-chain exercises stretch the anterior cruciate ligament more than closed-kinetic-chain exercises: In-vivo assessment of anterior cruciate ligament length change.

BACKGROUND: Usage of open-kinetic-chain (OKC) or closed-kinetic-chain (CKC) exercises during rehabilitation planning after anterior cruciate ligament (ACL) reconstruction has been debated for decades. However, the ACL elongation pattern during different rehabilitation exercises at different loadings remains unclear. OBJECTIVES: This study aimed to determine the effects of OKC and CKC exercises on the length of ACL anteromedial bundle (AMB) and posterolateral bundle (PLB) to provide biomechanical support for making rehabilitation schedules. DESIGN: Laboratory Descriptive Study. METHOD: Eighteen healthy volunteers were asked to perform two OKC motions, including non-weight-bearing and 10 kg loaded seated knee extension (OKC-0, OKC-10), as well as two CKC motions, including box squat (BS) and deep single-legged lunge (Lunge). Techniques of 2D-to-3D image registration and 3D ligament simulation were used to quantify length changes of ACL. RESULTS: The motion which led to the least and most ACL elongation were OKC-0 and OKC-10, respectively. The AMB and PLB were significantly longer in OKC-10 than those in OKC-0 during 0-60° and 0-55° of knee flexion (p < 0.01). Compared with reference length, the AMB and PLB were stretched during 0-30° and 0-10° respectively during OKC-10. During CKC exercises, the AMB and PLB were also stretched from 0 to 25°and 0-5°, respectively. Additionally, no significant difference was found in the length change of ACL bundles between BS and lunge. CONCLUSIONS: OKC-0 may be safe for the rehabilitation program after ACL reconstruction, and loaded exercises shall be applied when restricted with >30° in early-stage rehabilitation.

A Novel Approach for Cable Tension Monitoring Based on Mode Shape Identification.

Estimation and monitoring of cable tension is of great significance in the structural assessment of cable-supported bridges. For short cables, the traditional cable tension identification method via frequency measurement has large errors due to the influence of complex boundaries, which affect the accuracy of estimation. A new cable tension estimation method based on mode shape identification with a multiple sensor arrangement on the cable can take the influence of boundary conditions into account and its accuracy has been verified. However, it requires more sensors compared to the traditional frequency-based method, which will significantly increase the cost of long-term monitoring in practice. Therefore, a novel approach for cable tension monitoring considering both cost and accuracy is further proposed in this study. The approach adopts multiple sensors to measure the influence of boundary conditions. Then, only a single sensor is required for long-term monitoring of the cable. In this paper, an analytical model of the cable is firstly established. The influence of boundary conditions is calculated, which ensures the accuracy of mode shape identification. Furthermore, a field experiment is carried out to verify the effectiveness of the new approach. The results have demonstrated the effectiveness and accurateness of the proposed method in long-term short cable tension monitoring.

Asymmetry of Posterior Condyles in Resection Plane and Axial Curvature for Total Knee Arthroplasty.

OBJECTIVE: Understanding the morphology of the distal femur is essential for improving bone-implant match in total knee arthroplasty (TKA) and understanding the mechanisms behind knee kinematics. However, little is known about the asymmetry of the posterior condyles. Thus, this study aimed to thoroughly investigate asymmetries in sizes and shapes between the medial and lateral posterior condyles before and after femoral resections during TKA in osteoarthritic (OA) knees. METHODS: Three-dimensional femoral models of 74 OA knees were constructed using computed tomography images. The morphologic measurements of the posterior condyle pre- and post-simulated osteotomy for TKA included the radii of the posterior condyles fitted to a circle on the sagittal and axial planes of the femoral coordinate system, the inclination angle of the articular surface and resected surface, and the width and height of the resected surface. Differences in the data were assessed using Student's t-test, and correlations were evaluated using the Pearson product-moment correlation. RESULTS: The radii of the medial posterior condyles fitted to the circle were, on average, 6 mm larger than those of the lateral condyles on the axial plane (p < 0.001) and 0.7 mm smaller than those of the lateral condyles on the sagittal plane (p = 0.046). The inclination angles of the medial and lateral posterior condyles on the axial plane were significantly different with both pre-simulated and post-simulated osteotomy, respectively (both p < 0.001). The resected plane of the lateral posterior condyles displaced opposite inclination directions between the distal and proximal portions. Neither heights or widths of the medial posterior condyles were significantly different from those of their lateral counterparts (both p > 0.107). CONCLUSIONS: This study found asymmetrical inclination of the resected surface and coronal radii between the medial and lateral posterior condyles, which may relate to the posterolateral overhang of the lateral condyle after TKA and the progression of the knee OA. These findings provides valuable morphological information and may help improve the implant designs for TKA.

High femoral anteversion in osteoarthritic knees, particularly for severe valgus deformity.

OBJECTIVE: Increased femoral anteversion (FA) has been correlated with less varus deformities in osteoarthritic (OA) knees, but the relationship between FA and the degree of valgus deformity in osteoarthritic (OA) knees is still largely unknown. We aimed to thoroughly analyze the distribution of FA in relation to varus or valgus deformities of the lower extremity in OA knees, and to further clarify the relationship between FA and trochlear morphology. METHODS: 235 lower extremities with OA knees were divided into five groups according to the mechanical tibiofemoral angle: excessive valgus (< - 10°), moderate valgus (- 10° to - 3°), neutral (- 3° to 3°), moderate varus (3° to 10°), and excessive varus (> 10°). FA (measured using the posterior condylar axis [pFA] and the transepicondylar axis [tFA]) was measured, and the relationships of FA to the mechanical tibiofemoral angle and femoral trochlear morphology were identified. RESULTS: Excessive FA (pFA ≥ 20°) was observed in 30.2% of all patients and in 58.8% of patients in the excessive valgus group. pFA showed a strong correlation with mechanical tibiofemoral angle (p = 0.018). Both the pFA and the tFA of patients in the excessive valgus group were greater than those in other four groups (all p ≤ 0.037). There were significant correlations between tFA and trochlear parameters, including the sulcus angle (SA), lateral trochlear slope (LTS), and medial trochlear slope (MTS) (all p ≤ 0.028). CONCLUSION: High FA is prevalent, particularly in severe valgus knees, and FA is significantly related to the femoral trochlear morphology in OA knees. With the aim of improving the patellofemoral prognosis and complications, high FA should be considered during total knee arthroplasty.

Effect of Time After Injury on Tibiofemoral Joint Kinematics in Anterior Cruciate Ligament-Deficient Knees During Gait.

Background: Anterior cruciate ligament (ACL) injury can lead to changes in tibiofemoral kinematics during gait, but the detailed short-term kinematic changes after ACL injury are still unknown. Purpose: To measure tibiofemoral kinematics during gait in ACL-deficient (ACLD) knees over time after ACL injury. Study Design: Controlled laboratory study. Methods: The authors categorized 76 patients with unilateral ACLD knees into 4 groups based on the time from injury: <3 months (group 1), 3 to 6 months (group 2), >6 to 12 months (group 3), and >12 months (group 4). The controls were 20 participants with ACL-intact knees. Changes in the knee kinematics and range of motion during gait were compared among ACLD groups and those with ACL-intact knees. Results: Compared with controls, the range of motion of flexion in group 1 was significantly lower (6°; P = .033), and the mean knee flexion was significantly increased (0.7°-3.4°) in groups 1 to 4 (all P ≤ .004). There was more internal tibial rotation (2.9°-4.3°) in group 1 and 2, and more anterior tibial translation (4.3 mm) in group 1 during the stance or swing phases than in controls (P ≤ .049 for all). The mean internal tibial rotation and anterior tibial translation significantly decreased from group 1 to group 4 (P < .001 for both). Compared with controls, the mean medial tibial translation was significantly greater (1.2-2.5 mm) in all groups, and more medial tibial translations (2.4-3.7 mm) were observed during the stance phase in groups 1, 3, and 4 (P ≤ .047 for all). Conclusion: ACLD knees displayed a motion impairment walking strategy within 3 months, and a higher-flexion walking strategy increased with time after injury. Excessive anterior translation and internal rotation of the tibia tended to return to normal, while excessive medial translation of the tibia increased in ACLD knees after 6 months postinjury. These results may provide new insight into the compensatory mechanisms and risk factors for premature osteoarthritis in ACLD knees.

Unusual Freshwater-Related Infections Caused by Haematospirillum jordaniae.

Freshwater-related infections can be caused by a broad range of pathogens, potentially leading to skin and soft tissue, pulmonary, gastrointestinal, or even systemic diseases. Haematospirillum jordaniae (H. jordaniae),a gram-negative, aerobic organism previously regarded solely as an environmental microbe, has been classified as a pathogen capable of causing human infection in the United States. There has been only one other case reported in the literature of H. jordaniae infection, and little is known about the pathogenesis.The presentation and progression of clinical symptoms in our cases indicate freshwater cutaneous injury as the most likely route of H. jordaniae infection. We present two cases of H. jordaniae infection in elderly males. Both patients had freshwater exposure and skin injury resulting in sepsis, cellulitis at the site of injury, and bacteremia. Additionally, one patient presented with an acute deep venous thrombosis. The diagnosis of H. jordaniae was confirmed using Sanger sequencing 16s ribosomal RNA data. Antimicrobial therapy included piperacillin-tazobactam, ceftazidime, and levofloxacin. Both patients recovered successfully. While clinical cases and literature involving the newly classified human pathogen H. jordaniae are still rare, it is crucial to recognize the potential emergence of environmental organisms, previously believed to be harmless, as human pathogens. In cases of bacteremia and cellulitis with recent freshwater exposure and injury, H. jordaniae infection should be considered as part of the differential diagnosis.

[Digital study on the relationship between position of patellar high point and shape of osteotomy surface in Chinese].

Objective: To measure the position of patellar high point and the shape of the osteotomy surface, and to analyze their relationship, distribution, and gender differences. Methods: A total of 127 patients who needed anterior cruciate ligament reconstruction or meniscus repair due to trauma between September 2020 and September 2021 were selected as the research subjects. There were 71 males and 56 females, with an average age of 30.5 years (range, 19-43 years). There were significant differences in height and body weight between male and female patients ( P<0.05), but no significant difference in age and body mass index ( P>0.05). The three-dimensional model of the patella was reconstructed in Mimics software based on the CT images of the knee joint, and then imported into Geomagic Studio software for virtual osteotomy of the patella. The horizontal axis and vertical axis of the osteotomy surface represented the total width (W) and total height (H) of the osteotomy surface, respectively. Then the osteotomy surface was divided into four quadrants with the two axes: inner proximal, inner distal, outer proximal, and outer distal, and the inner width (W1), proximal height (H1), outer width (W2), and distal height (H2) were measured. The midpoint of the patellar ridge was selected as the patellar high point, and the point projected onto the osteotomy surface was defined as the optimal point for patellar prosthesis positioning (OPPP). The distances of OPPP on the horizontal axis (L1) and vertical axis (L2) relative to the center of the osteotomy surface were measured and L1/W1 and L2/H1 were also calculated; the quadrant distribution of OPPP was recorded. The patients were grouped according to gender, and the morphological parameters of the osteotomy surface (W, W1, W2, H, H1, H2) and the parameters related to the position of the OPPP (L1, L2, L1/W1, L2/H1) were analyzed between groups. Results: The width and height of each osteotomy surface of the patella in males were significantly larger than those in females ( P<0.05). As for the relationship between OPPP and osteotomy surface, the L1 of both male and female patients was 1-7 mm, and there was no significant difference in the distribution between the two groups ( χ 2=8.068, P=0.149); L1/W1 in both male and female patients was mainly 1/10-3/10. The L2 of male patients was 0-5 mm, and that of female patients was -1-4 mm; the difference in distribution between the two groups was significant ( χ 2=15.500, P=0.006); L2/H1 in both male and female patients was mainly 0-1/5. The OPPP of male patients was mainly distributed in the inner proximal (98.59%) and outer proximal (1.41%) quadrants, while the female patients were distributed in the inner proximal (91.07%), inner distal (7.14%), and outer proximal (1.79%) quadrants. There was significant difference in the OPPP quadrant distribution between the two groups ( χ 2=5.186, P=0.036). Conclusion: The OPPP points are widely distributed but mainly concentrated on around 1/5 of the medial patella surface and around 1/10 of the superior patella surface. A small portion of females' OPPP were inferior while all males' OPPP were superior to the center of the patella.

CYP11A1­derived vitamin D hydroxyderivatives as candidates for therapy of basal and squamous cell carcinomas.

Hydroxyderivatives of vitamin D3, including classical 1,25(OH)2D3 and novel CYP11A1­derived hydroxyderivatives, exert their biological activity by acting as agonists on the vitamin D receptor (VDR) and inverse agonists on retinoid­related orphan receptors (ROR)α and γ. The anticancer activities of CYP11A1­derived hydroxyderivatives were tested using cell biology, tumor biology and molecular biology methods in human A431 and SCC13 squamous (SCC)­ and murine ASZ001 basal (BCC)­cell carcinomas, in comparison with classical 1,25(OH)2D3. Vitamin D3­hydroxyderivatives with or without a C1α(OH) inhibited cell proliferation in a dose­dependent manner. While all the compounds tested had similar effects on spheroid formation by A431 and SCC13 cells, those with a C1α(OH) group were more potent in inhibiting colony and spheroid formation in the BCC line. Potent anti­tumorigenic activity against the BCC line was exerted by 1,25(OH)2D3, 1,20(OH)2D3, 1,20,23(OH)3D3, 1,20,24(OH)3D3, 1,20,25(OH)3D3 and 1,20,26(OH)3D3, with smaller effects seen for 25(OH)D3, 20(OH)D3 and 20,23(OH)2D3. 1,25(OH)2D3, 1,20(OH)2D3 and 20(OH)D3 inhibited the expression of GLI1 and ß­catenin in ASZ001 cells. In A431 cells, these compounds also decreased the expression of GLI1 and stimulated involucrin expression. VDR, RORγ, RORα and CYP27B1 were detected in A431, SCC13 and ASZ001 lines, however, with different expression patterns. Immunohistochemistry performed on human skin with SCC and BCC showed nuclear expression of all three of these receptors, as well as megalin (transmembrane receptor for vitamin D­binding protein), the level of which was dependent on the type of cancer and antigen tested in comparison with normal epidermis. Classical and CYP11A1­derived vitamin D3­derivatives exhibited anticancer­activities on skin cancer cell lines and inhibited GLI1 and ß­catenin signaling in a manner that was dependent on the position of hydroxyl groups. The observed expression of VDR, RORγ, RORα and megalin in human SCC and BCC suggested that they might provide targets for endogenously produced or exogenously applied vitamin D hydroxyderivatives and provide excellent candidates for anti­cancer therapy.

Primary Vaginal Adenocarcinoma of Intestinal-Type: A Case Report of a Rare Tumor With Review of Histology, Differential Diagnosis, and Literature.

Intestinal-type adenocarcinoma is a rare primary vaginal carcinoma. Vaginal adenocarcinomas are most frequently a metastatic lesion, and less commonly, have clear cell histology and occur in young women with diethylstilbestrol (DES) exposure in utero. Due to the limited diagnostic power of immunohistochemistry (IHC) in differentiating primary from metastatic adenocarcinoma of the vagina, clinical and radiological correlation is critical in this scenario. The prognosis of this tumor depends on the patient's age, tumor stage, tumor differentiation, lymph node status, and distant metastasis. Several treatment modalities are present depending on the tumor stage. We present a case of primary adenocarcinoma of the vagina and describe the histopathologic features including the immunoprofile of the tumor and discuss the clinicopathologic features, differential diagnosis, diagnostic challenges, and a brief overview of the literature about age, size, site, immunohistochemical staining, and DES exposure.

In-vivo tibiofemoral kinematics of the normal knee during closed and open kinetic chain exercises: A comparative study of box squat and seated knee extension.

A rehabilitation program after anterior cruciate ligament reconstruction is of great importance to obtain a satisfactory prognosis after surgery. However, there is still an onging debate over whether closed kinetic chain or open kinetic chain exercises should be chosen. Our study was designed to compare the in vivo tibiofemoral kinematics during closed kinetic chain and open kinetic chain exercises. Eighteen healthy volunteers were asked to perform box squat and unloaded/10 kg-loaded seated knee extension. In vivo 3-dimensional analysis of tibiofemoral kinematics of different motions were determined using a dual fluoroscopic imaging system. The study found significantly more tibial anterior displacement during loaded seated knee extension than during unloaded seated knee extension from 25°-50° of knee flexion (p ≤ 0.031). The knees exhibited significantly more internal tibial rotation and lateral tibial translation during the box squat than both seated knee extensions during mid-flexion. In addition, the knees showed less internal-external (IE) range of motion (ROM) from 20°- 75° of flexion (p < 0.001) and medial-lateral (ML) ROM from 75° to full extension (p ≤ 0.006) during box squat than both extensions. This knowledge may help optimize rehabilitation plans for patients post ACL reconstruction.

miR-125a-5p Regulates Osteogenic Differentiation of Human Adipose-Derived Mesenchymal Stem Cells under Oxidative Stress.

Adipose-derived mesenchymal stem cells (ADSCs) are a well-recognized multilineage stem cell with vital clinical feasibility for tissue regeneration. Extensive evidence indicates that oxidative stress and microRNAs (miRNAs/miRs) play an important role in the osteoinduction of adipose-derived mesenchymal stem cells. In this study, we investigated the mechanism of miR-125a-5p in regulating the osteogenesis of human adipose-derived mesenchymal stem cells (hADSCs) under oxidative stress. The expression of miR-125a-5p lessened gradually during the osteogenic differentiation of hADSCs. Relative to the negative group, the expression levels of runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), osteocalcin (OCN), and osterix in the miR-125a-5p group were marked lower than those in the miR-125a-5p inhibitor group. The levels of p16, p21, p53, miR-125a-5p, and ROS during osteoinduction of hADSCs were assessed in vitro under oxidative stress and were observed to be upregulated. Further experiments showed that oxidative stress and miR-125a-5p together suppressed the expression of VEGF during osteogenic differentiation of hADSCs and that the inhibition of miR-125a-5p reversed the effect of oxidative stress. In short, our study indicated that miR-125a-5p is induced under oxidative stress and inhibits the expression of VEGF, leading to the reduction of osteogenic differentiation of hADSCs. Our outcomes showed that miR-125a-5p could be a potential clinical target for bone repairing.

Chronic Hand Swelling and Dactylitis in Leprosy: A Case Report and Review of the Literature.

Leprosy is an infectious disease that is associated with various types of presentations. Diagnosis of the disease can be tricky in cases of atypical presentations. We report a unique case of leprosy characterized by chronic hand swelling, dactylitis, and seropositive laboratory markers, which was diagnosed in a rheumatology clinic.

Hemosiderotic dermatofibroma mimicking melanoma: A case report and review of the literature.

Hemosiderotic dermatofibroma (HDF) often mimics melanoma clinically. A definite diagnosis relies on histopathological evaluation and immunohistochemistry. As it can progress to aneurysmal dermatofibroma (ADF), complete excision is recommended.

Diagnosing Basal Cell Carcinoma of the Vulva: A Case Report and Review of the Literature.

Basal cell carcinoma (BCC) is a highly prevalent epidermal neoplasm that most commonly occurs in regions of sun-exposed skin, though rare cases arise in sun-protected areas. BCCs of the vulva account for a small fraction of cases and can be mistaken for other cutaneous genital pathologies on clinical examination. Here we report a case of vulvar BCC that presented as a firm, tender bilateral lesion of the mons pubis and was diagnosed by histopathology and immunostaining for classical BCC markers.

Elongation and orientation pattern of the medial patellofemoral ligament during lunging.

Unfavorable clinical outcomes after medial patellofemoral ligament (MPFL) reconstruction, such as early osteoarthritis of the patellofemoral joint, were considered to be associate with tunnel malpositioning. Length change studies have found that small changes in the femoral position can cause great changes in elongation trends. Further studying the MPFL kinematics may help us to understand the consequences of tunnel malpositioning and optimize the reconstruction techniques. Fifteen healthy subjects were studied with a combined computed tomography and biplane fluoroscopic imaging technique during a lunge motion. Five femoral and three patellar attachments were used to simulate different MPFL bundles. Kinematics of MPFL was defined as elongation and orientation changes (i.e., deviation angle and elevation angle). The mean deviation angle was 28.7° (95% confidence interval, 28.0°-29.4°) at full extension and remained nearly unchanged up to 60° of flexion, and increased to 56.5° (54.1°-58.9°) at 110°. The elevation angle decreased linearly from 12.6° (9.3°-15.9°) at full extension to -86.2° (-92.7-79.7°) at 110° of flexion. The MPFL was most stretched anteriorly and laterally relative to femur from full extension to 30° of flexion and remained near isometric beyond 30°. The current study found that proximal and anterior femoral attachments caused excessive lateral stretching of the MPFL at deeper flexion angles. Such abnormal MPFL kinematics may subsequently cause overconstraint and increased cartilage pressures of the medial patellofemoral joint.