Bony Landmarks of the Anterior Cruciate Ligament Tibial Footprint A Detailed Analysis Comparing 3-Dimensional Computed Tomography Images to Visual and Histological Evaluations

Background: Although the importance of tibial tunnel position for achieving stability after anterior cruciate ligament (ACL) reconstruction was recently recognized, there are fewer detailed reports of the anatomy of the tibial topographic footprint compared with the femoral side. Hypothesis: The ACL tibial footprint has a relationship to bony prominences and surrounding bony landmarks. Study Design: Descriptive laboratory study. Methods: This study consisted of 2 anatomic procedures for the identification of bony prominences that correspond to the ACL tibial footprint and 3 surrounding landmarks: the anterior ridge, lateral groove, and intertubercular fossa. In the first procedure, after computed tomography (CT) was performed on 12 paired, embalmed cadaveric knees, 12 knees were visually observed, while their contralateral knees were histologically observed. Comparisons were made between macroscopic and microscopic findings and 3-dimensional (3D) CT images of these bony landmarks. In the second procedure, the shape of the bony prominence and incidence of their bony landmarks were evaluated from the preoperative CT data of 60 knee joints. Results: In the first procedure, we were able to confirm a bony prominence and all 3 surrounding landmarks by CT in all cases. Visual evaluation confirmed a small bony eminence at the anterior boundary of the ACL. The lateral groove was not confirmed macroscopically. The ACL was not attached to the lateral intercondylar tubercle, ACL tibial ridge, and intertubercular space at the posterior boundary. Histological evaluation confirmed that the anterior ridge and lateral groove were positioned at the anterior and lateral boundaries, respectively. There was no ligament tissue on the intercondylar space corresponding to the intercondylar fossa. In the second investigation, the bony prominence showed 2 morphological patterns: an oval type (58.3%) and a triangular type (41.6%). The 3 bony landmarks, including the anterior ridge, lateral groove, and intertubercular fossa, existed in 96.6%, 100.0%, and 96.6% of the cases, respectively. Conclusion: There is a bony prominence corresponding to the ACL footprint and bony landmarks on the anterior, posterior, and lateral boundaries.ArticleAMERICAN JOURNAL OF SPORTS MEDICINE. 42(6):1433-1440 (2014)journal articl

Nonsteroidal anti-inflammatory drugs and acetaminophen ameliorate muscular mechanical hyperalgesia developed after lengthening contractions via cyclooxygenase-2 independent mechanisms in rats.

Nonsteroidal anti-inflammatory drugs and acetaminophen are cyclooxygenase inhibitors commonly used as symptomatic medicines for myofascial pain syndrome. Using the selective inhibitors celecoxib and zaltoprofen, cyclooxygenase-2 has been shown to be involved in the initiation, but not the maintenance, of muscular mechanical hyperalgesia induced by lengthening contractions, which serves as a useful model for the study of myofascial pain syndrome. The effect of other cyclooxygenase-2 inhibitors, such as acetylsalicylic acid, ibuprofen, loxoprofen sodium, and acetaminophen, on muscular mechanical hyperalgesia during maintenance has not been studied. Here, we examined the analgesic effects of the nonsteroidal anti-inflammatory drugs and acetaminophen on the model. Consistent with previous studies, mechanical withdrawal threshold of the muscle was significantly decreased and reached its lowest level 24 h after lengthening contractions. Celecoxib had no effect on muscular mechanical hyperalgesia, when orally administered 24 h after lengthening contractions. In contrast, acetylsalicylic acid, ibuprofen, loxoprofen sodium, and acetaminophen increased the withdrawal threshold, which had decreased by lengthening contractions, in a dose-dependent manner. These results demonstrate the analgesic actions of nonsteroidal anti-inflammatory drugs and acetaminophen in the maintenance process of lengthening contraction-induced muscular mechanical hyperalgesia, which may occur through cyclooxygenase-2 independent mechanisms

Bony Landmarks of the Anterior Cruciate Ligament Tibial Footprint

Background: Although the importance of tibial tunnel position for achieving stability after anterior cruciate ligament (ACL) reconstruction was recently recognized, there are fewer detailed reports of the anatomy of the tibial topographic footprint compared with the femoral side. Hypothesis: The ACL tibial footprint has a relationship to bony prominences and surrounding bony landmarks. Study Design: Descriptive laboratory study. Methods: This study consisted of 2 anatomic procedures for the identification of bony prominences that correspond to the ACL tibial footprint and 3 surrounding landmarks: the anterior ridge, lateral groove, and intertubercular fossa. In the first procedure, after computed tomography (CT) was performed on 12 paired, embalmed cadaveric knees, 12 knees were visually observed, while their contralateral knees were histologically observed. Comparisons were made between macroscopic and microscopic findings and 3-dimensional (3D) CT images of these bony landmarks. In the second procedure, the shape of the bony prominence and incidence of their bony landmarks were evaluated from the preoperative CT data of 60 knee joints. Results: In the first procedure, we were able to confirm a bony prominence and all 3 surrounding landmarks by CT in all cases. Visual evaluation confirmed a small bony eminence at the anterior boundary of the ACL. The lateral groove was not confirmed macroscopically. The ACL was not attached to the lateral intercondylar tubercle, ACL tibial ridge, and intertubercular space at the posterior boundary. Histological evaluation confirmed that the anterior ridge and lateral groove were positioned at the anterior and lateral boundaries, respectively. There was no ligament tissue on the intercondylar space corresponding to the intercondylar fossa. In the second investigation, the bony prominence showed 2 morphological patterns: an oval type (58.3%) and a triangular type (41.6%). The 3 bony landmarks, including the anterior ridge, lateral groove, and intertubercular fossa, existed in 96.6%, 100.0%, and 96.6% of the cases, respectively. Conclusion: There is a bony prominence corresponding to the ACL footprint and bony landmarks on the anterior, posterior, and lateral boundaries.ArticleAMERICAN JOURNAL OF SPORTS MEDICINE. 42(6):1433-1440 (2014)journal articl

Katanin p60 Contributes to Microtubule Instability around the Midbody and Facilitates Cytokinesis in Rat Cells

<div><p>The completion of cytokinesis is crucial for mitotic cell division. Cleavage furrow ingression is followed by the breaking and resealing of the intercellular bridge, but the detailed mechanism underlying this phenomenon remains unknown. Katanin is a microtubule-severing protein comprised of an AAA ATPase subunit and an accessory subunit designated as p60 and p80, respectively. Localization of katanin p60 was observed at the midzone to midbody from anaphase to cytokinesis in rat cells, and showed a ring-shaped distribution in the gap between the inside of the contractile ring and the central spindle bundle in telophase. Katanin p60 did not bind with p80 at the midzone or midbody, and localization was shown to be dependent on microtubules. At the central spindle and the midbody, no microtubule growth plus termini were seen with katanin p60, and microtubule density was inversely correlated with katanin p60 density in the region of katanin p60 localization that seemed to lead to microtubule destabilization at the midbody. Inhibition of katanin p60 resulted in incomplete cytokinesis by regression and thus caused the appearance of binucleate cells. These results suggest that katanin p60 contributes to microtubule instability at the midzone and midbody and facilitates cytokinesis in rat cells.</p> </div

Katanin p60 localization was restricted in the area of non-growing microtubules during cytokinesis.

<p>3Y1 cells labeled for katanin p60 (green), EB1 (red) (EB1), and DNA (blue). Merge indicates merged images of katanin p60, EB1, and DNA, showing the localization of katanin p60 at metaphase (Meta), telophase (Telo), and cytokinesis (Cyto) during mitosis. Scale bars: 10 µm. Samples were fixed in methanol and analyzed by confocal laser scanning fluorescence microscopy (FV-1000D; Olympus). </p

Katanin p60 inhibition leads to incomplete cytokinesis.

<div><p>A. 3Y1 cells labeled for katanin p60 (green), microtubules (red), and DNA (blue). Control and siRNA indicate non-treated 3Y1 cells and 3Y1 cells transfected with katanin p60 siRNA, respectively. Scale bars: 5 µm. Samples were fixed in methanol and analyzed by confocal laser scanning fluorescence microscopy (FV-1000D; Olympus).</p> <p>B and C. Time courses of differential interference contrast (DIC) microscopy images at mitosis of control siRNA-treated cell (B) and katanin p60 siRNA-treated cell (C). Scale bar: 20 µm.</p> <p>D. Types of cytokinesis of siRNA-treated cells are shown. Open and shaded boxes indicate normal cytokinesis completion (N) and incomplete cytokinesis by regression leading to binucleate cell formation (B), respectively. Averages and SD were calculated from three independent experiments (total 13 and 15 independent observation fields of control and katanin p60 siRNA treatment, respectively). Control: control siRNA-treated cell; Katanin p60: katanin p60 siRNA-treated cell.</p></div

Model for Katanin p60 function during cytokinesis.

<div><p>A.Model of katanin p60 function at the midbody.</p> <p>B. Katanin p60 function through the cell cycle.</p></div

Katanin p60 was bundled with microtubules by contractility of the contractile ring and distributed in a microtubule-dependent manner.

<div><p>A. 3Y1 cells were treated with 10 µM blebbistatin for 1 h and then labeled for katanin p60 (green), actin (red), and DNA (blue). Merge indicates merged images of katanin p60, actin, and DNA, showing the localization of katanin p60, microtubules, and the contractile ring at anaphase (Ana) and telophase (Telo) during mitosis. Scale bars: 10 µm. Samples were fixed in methanol and analyzed by confocal laser scanning fluorescence microscopy (FV-1000D; Olympus).</p> <p>B. 3Y1 cells were treated with 10 µM blebbistatin for 1 h and then labeled for katanin p60 (green), β-tubulin (red), and DNA (blue). Merge indicates merged images of katanin p60, β-tubulin and DNA, showing the localization of katanin p60 and microtubules at telophase (Telo) during mitosis. Cross-section showing vertical images of the distributions of katanin p60 (green), β-tubulin (red), and DNA (blue). Green arrowheads indicate vertical analysis point corresponding to the “Center” of the plane where katanin p60 was present. Red arrowheads indicate vertical analyses points corresponding to “Right” and “Left” at both sides neighboring the plane where katanin p60 was present. “B” and “T” indicate “Bottom” and “Top” of the cell, respectively. Scale bars: 10 µm. Samples were fixed in methanol and analyzed by confocal laser scanning fluorescence microscopy (FV-1000D; Olympus). </p> <p>C. 3Y1 cells were treated with 10 µM nocodazole for 30 min, and then labeled for katanin p60 (green), β-tubulin (red), and DNA (blue). Merge indicates merged images of katanin p60, β-tubulin, and DNA at prophase – metaphase (Pro – Meta) and at cytokinesis (Cytokinesis). Both katanin p60 and microtubules disappeared. Scale bars: 10 µm. Samples were fixed in methanol and analyzed by fluorescence microscopy (Axioskop II; Carl Zeiss).</p></div

Katanin p60 is localized at both the spindle pole and midbody.

<div><p>A. 3Y1, RL34, and FAA indicate immunostained images of 3Y1 cells, RL34 cells, and FAA-HTC1 cells, respectively. Cells were labeled for katanin p60 (green), β-tubulin (microtubules; red), and DNA (blue). Merge indicates merged images of katanin p60, ß-tubulin, and DNA, showing the localization of katanin p60 at the spindle pole (Metaphase) and midbody (Cytokinesis) during mitosis. Scale bars: 10 µm. Samples were fixed in methanol and analyzed by fluorescence microscopy (Axioskop II; Carl Zeiss). </p> <p>B. Inhibition of katanin p60 by katanin siRNA was determined by quantitative RT-PCR 24 h after transfection. Katanin p60 mRNA expression levels were normalized relative to TATA Binding Protein (TBP) mRNA as an internal control. </p> <p>C. Inhibition of katanin p60 by katanin siRNA was determined by Western blotting analysis 48 h after transfection. Four different siRNAs derived from the rat katanin p60 sequence were used independently (1 - 4) and mixed (Mix). IB indicates immunoblotting with anti-katanin p60 antibody (IB: Katanin p60) and with anti-actin antibody (IB: Actin). </p> <p>D. 3Y1 cells labeled for katanin p60 (green), β-tubulin (red), and DNA (blue). Merge indicates merged images of katanin p60, β-tubulin, and DNA, showing the localization of katanin p60 at the spindle pole (Metaphase) and midbody (Cytokinesis) during mitosis. 3Y1 cells were transfected with control siRNA (Control) or katanin p60 siRNA (siRNA). Scale bars: 10 µm. Samples were fixed in methanol and analyzed by confocal laser scanning fluorescence microscopy (FV-1000D; Olympus).</p></div