scholarly journals ACL Size, but Not Signal Intensity, Is Influenced by Sex, Body Size, and Knee Anatomy

2021 ◽  
Vol 9 (12) ◽  
pp. 232596712110638
Author(s):  
Samuel C. Barnett ◽  
Martha M. Murray ◽  
Sean W. Flannery ◽  
Danilo Menghini ◽  
Braden C. Fleming ◽  
...  
Keyword(s):  
Signal Intensity ◽  
Tibial Slope ◽  
Cross Sectional Area ◽  
Intercondylar Notch ◽  
Activity Levels ◽  
Sectional Area ◽  
Tissue Quality ◽  
Cross Sectional ◽  
Notch Width ◽  
Intercondylar Notch Width

Background: Little is known about sex-based differences in anterior cruciate ligament (ACL) tissue quality in vivo or the association of ACL size (ie, volume) and tissue quality (ie, normalized signal intensity on magnetic resonance imaging [MRI]) with knee anatomy. Hypothesis: We hypothesized that (1) women have smaller ACLs and greater ACL normalized signal intensity compared with men, and (2) ACL size and normalized signal intensity are associated with age, activity levels, body mass index (BMI), bicondylar width, intercondylar notch width, and posterior slope of the lateral tibial plateau. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Knee MRI scans of 108 unique ACL-intact knees (19.7 ± 5.5 years, 62 women) were used to quantify the ACL signal intensity (normalized to cortical bone), ligament volume, mean cross-sectional area, and length. Independent t tests were used to compare the MRI-based ACL parameters between sexes. Univariate and multivariate linear regression analyses were used to investigate the associations between normalized signal intensity and size with age, activity levels, BMI, bicondylar width, notch width, and posterior slope of the lateral tibial plateau. Results: Compared with men, women had significantly smaller mean ACL volume (men vs women: 2028 ± 472 vs 1591 ± 405 mm3), cross-sectional area (49.4 ± 9.6 vs 41.5 ± 8.6 mm2), and length (40.8 ± 2.8 vs 38.1 ± 3.1 mm) ( P < .001 for all), even after adjusting for BMI and bicondylar width. There was no difference in MRI signal intensity between men and women (1.15 ± 0.24 vs 1.12 ± 0.24, respectively; P = .555). BMI, bicondylar width, and intercondylar notch width were independently associated with a larger ACL ( R 2 > 0.16, P < .001). Younger age and steeper lateral tibial slope were independently associated with shorter ACL length ( R 2 > 0.03, P < .04). The combination of BMI and bicondylar width was predictive of ACL volume and mean cross-sectional area ( R 2 < 0.3). The combination of BMI, bicondylar width, and lateral tibial slope was predictive of ACL length ( R 2 = 0.39). Neither quantified patient characteristics nor anatomic variables were associated with signal intensity. Conclusion: Men had larger ACLs compared with women even after adjusting for BMI and knee size (bicondylar width). No sex difference was observed in signal intensity, suggesting no difference in tissue quality. The association of the intercondylar notch width and lateral tibial slope with ACL size suggests that the influence of these anatomic features on ACL injury risk may be partially explained by their effect on ACL size. Registration: NCT02292004 and NCT02664545 ( ClinicalTrials.gov identifier).

scholarly journals Changes in Cross-Sectional Area and Signal Intensity of Healing ACLs and ACL Grafts in the First Two Years After Surgery

2019 ◽  
Vol 7 (7_suppl5) ◽  
pp. 2325967119S0035
Author(s):  
Ata M. Kiapour ◽  
Kirsten Ecklund ◽  
Martha M. Murray ◽  
Braden C. Fleming
Keyword(s):  
Signal Intensity ◽  
Insertion Site ◽  
Elevation Angle ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Tissue Quality ◽  
Cross Sectional ◽  
Acl Graft ◽  
Notch Width ◽  
The Cross

Objectives: The quality of a repaired anterior cruciate ligament (ACL) or reconstructed graft is typically quantified by evaluating knee, lower extremity or subject performance. However, magnetic resonance (MR) imaging of the healing ACL or graft provides a more direct measure of the tissue quality (i.e., signal intensity) and quantity (i.e., cross-sectional area). Here we used a quantitative MR imaging approach to evaluate longitudinal changes in graft size and signal intensity over the first 2 years after ACL reconstruction (ACLR). We also studied the structural changes in ACLs treated with a novel surgical repair procedure, Bridge-Enhanced ACL Repair (BEAR). We hypothesized that there would be differences in the cross-sectional area or signal intensity of the repaired ACL or reconstructed graft within 2 years after surgery, and that these structural properties correlate with knee anatomy. Methods: MR images of the patients recruited in the BEAR first-in-human trial (10 BEAR and 10 ACLR) were used to measure ACL/graft cross-sectional area and signal intensity at 3, 6, 12 and 24 months. ACL stump length, posterior slope of the medial and lateral tibial plateau, maximum depth of the medial tibial plateau, and sagittal ACL/graft elevation angle and femoral notch width were also measured from MRI. Notchplasty was defined as the difference between the post- and preoperative notch width. Results: Cross-sectional area of the grafts was 48-98% larger than the contralateral intact ACL at all time points (p<.01). The BEAR ACLs were 23-28% greater than the contralateral intact ACL at 3 and 6 months (p<.02), but similar at 12 and 24 months (Fig 1A). Both the BEAR and ACLR groups had a slightly higher signal intensity (indicative of lower tissue quality) at 3 months compared to the contralateral intact ACL, which then trended to a maximum at 6 months before reduction to the levels seen in the contralateral intact ACL at 24 months (p>.1; Fig 1B). The BEAR ACL had the same sagittal elevation angle as the contralateral intact ACL and coursed from insertion site to insertion site rather than from the femoral to tibial tunnel. The ACLR grafts coursed from tibial to femoral tunnels and were 6.5 º more vertical (p=.005) than the contralateral intact ACL. For the BEAR ACLs, the bigger notch correlated with bigger cross-sectional area, while a shorter ACL femoral stump, steeper lateral tibial slope and shallower medial tibial depth were associated with higher signal intensity (R2>.40; p<.05). Performance of notchplasty resulted in increased ACL cross-sectional area after BEAR procedure (p=.007; Fig 1). No anatomic features were correlated with ACL graft size or signal intensity. Conclusion: ACLR grafts continue to remodel over the first 2 years after surgery, whereas the remodeling of ACLs treated with the BEAR procedure occur predominantly in the first year. The BEAR procedure more closely restores the cross-sectional area and orientation in the sagittal plane than an ACL graft placed using a transtibial technique. The cross-sectional area of the repaired ACLs may be increased by performing a notchplasty at the time of surgery. [Figure: see text]

scholarly journals Changes in Cross-sectional Area and Signal Intensity of Healing Anterior Cruciate Ligaments and Grafts in the First 2 Years After Surgery

2019 ◽  
Vol 47 (8) ◽  
pp. 1831-1843 ◽  
Author(s):  
Ata M. Kiapour ◽  
Kirsten Ecklund ◽  
Martha M. Murray ◽  
Brett Flutie ◽  
Christina Freiberger ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Signal Intensity ◽  
Tibial Slope ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Resonance Imaging ◽  
Cross Sectional ◽  
Anterior Cruciate ◽  
Sagittal Orientation

Background: The quality of a repaired anterior cruciate ligament (ACL) or reconstructed graft is typically quantified in clinical studies by evaluating knee, lower extremity, or patient performance. However, magnetic resonance imaging of the healing ACL or graft may provide a more direct measure of tissue quality (ie, signal intensity) and quantity (ie, cross-sectional area). Hypotheses: (1) Average cross-sectional area or signal intensity of a healing ACL after bridge-enhanced ACL repair (BEAR) or a hamstring autograft (ACL reconstruction) will change postoperatively from 3 to 24 months. (2) The average cross-sectional area and signal intensity of the healing ligament or graft will correlate with anatomic features of the knee associated with ACL injury. Study Design: Cohort study; Level of evidence, 2. Methods: Patients with a complete midsubstance ACL tear who were treated with either BEAR (n = 10) or ACL reconstruction (n = 10) underwent magnetic resonance imaging at 3, 6, 12, and 24 months after surgery. Images were analyzed to determine the average cross-sectional area and signal intensity of the ACL or graft at each time point. ACL orientation, stump length, and bony anatomy were also assessed. Results: Mean cross-sectional area of the grafts was 48% to 98% larger than the contralateral intact ACLs at all time points ( P < .01). The BEAR ACLs were 23% to 28% greater in cross-sectional area than the contralateral intact ACLs at 3 and 6 months ( P < .02) but similar at 12 and 24 months. The BEAR ACLs were similar in sagittal orientation to the contralateral ACLs, while the grafts were 6.5° more vertical ( P = .005). For the BEAR ACLs, a bigger notch correlated with a bigger cross-sectional area, while a shorter ACL femoral stump, steeper lateral tibial slope, and shallower medial tibial depth were associated with higher signal intensity ( R2 > .40, P < .05). Performance of notchplasty resulted in an increased ACL cross-sectional area after the BEAR procedure ( P = .007). No anatomic features were correlated with ACL graft size or signal intensity. Conclusion: Hamstring autografts were larger in cross-sectional area and more vertically oriented than the native ACLs at 24 months after surgery. BEAR ACLs had a cross-sectional area, signal intensity, and sagittal orientation similar to the contralateral ACLs at 24 months. The early signal intensity and cross-sectional area of the repaired ACL may be affected by specific anatomic features, including lateral tibial slope and notch width—observations that deserve further study in a larger cohort of patients. Registration: NCT02292004 (ClinicalTrials.gov identifier)

scholarly journals Predictors of Healing Ligament Size and Magnetic Resonance Signal Intensity at 6 Months After Bridge-Enhanced Anterior Cruciate Ligament Repair

2019 ◽  
Vol 47 (6) ◽  
pp. 1361-1369 ◽  
Author(s):  
Martha M. Murray ◽  
Ata M. Kiapour ◽  
Leslie A. Kalish ◽  
Kirsten Ecklund ◽  
Christina Freiberger ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Magnetic Resonance ◽  
Signal Intensity ◽  
Cruciate Ligament ◽  
Quadriceps Strength ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Acl Repair ◽  
Cross Sectional ◽  
Anterior Cruciate

Background: Primary repair of the anterior cruciate ligament (ACL) augmented with a tissue engineered scaffold to facilitate ligament healing is a technique under development for patients with ACL injuries. The size (the amount of tissue) and signal intensity (the quality of tissue) of the healing ligament as visualized on magnetic resonance imaging (MRI) have been shown to be related to its strength in large animal models. Hypothesis: Both modifiable and nonmodifiable risk factors could influence the size and signal intensity of the repaired ligament in patients at 6 months after surgery. Study Design: Case series; Level of evidence, 4. Methods: 62 patients (mean age, 19.4 years; range, 14-35 years) underwent MRI of the knee 6 months after ACL repair augmented with an extracellular matrix scaffold. The signal intensity (normalized to cortical bone) and average cross-sectional area of the healing ligament were measured from the MRI stack obtained by use of a gradient echo sequence. Associations between these 2 measures and patient characteristics, which included demographic, clinical, and anatomic features, were determined by use of multivariable regression analysis. Results: A larger cross-sectional area of the repaired ligament at 6 months was associated with male sex, older age, and the performance of a larger notchplasty ( P < .05 for all associations). A lower signal intensity at 6 months, indicating greater similarity to normal ligament, was associated with a smaller tibial slope and greater side-to-side difference in quadriceps strength 3 months after surgery. Other factors, including preoperative body mass index, mechanism of injury, tibial stump length, and Marx activity score, were not significantly associated with either MRI parameter at 6 months. Conclusion: Modifiable factors, including surgical notchplasty and slower recovery of quadriceps strength at 3 months, were associated with a larger cross-sectional area and improved signal intensity of the healing ACL after bridge-enhanced ACL repair in this preliminary study. Further studies to determine the optimal size of the notchplasty and the most effective postoperative rehabilitation strategy after ACL repair augmented by a scaffold are justified. Registration: NCT02664545 (ClinicalTrials.gov identifier).

scholarly journals Higher Physiologic Platelet Counts in Whole Blood Are Not Associated With Improved ACL Cross-sectional Area or Signal Intensity 6 Months After Bridge-Enhanced ACL Repair

2020 ◽  
Vol 8 (7) ◽  
pp. 232596712092765 ◽  
Author(s):  
Christina Freiberger ◽  
Ata M. Kiapour ◽  
Shanshan Liu ◽  
Rachael N. Henderson ◽  
Samuel Barnett ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Magnetic Resonance ◽  
Blood Cell ◽  
Signal Intensity ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Acl Repair ◽  
Cross Sectional ◽  
Platelet Concentration ◽  
Male Sex

Background: A bridge-enhanced anterior cruciate ligament (ACL) repair (BEAR) procedure places an extracellular matrix implant, combined with autologous whole blood, in the gap between the torn ends of the ligament at the time of suture repair to stimulate healing. Prior studies have suggested that white blood cell (WBC) and platelet concentrations significantly affect the healing of other musculoskeletal tissues. Purpose/Hypothesis: The purpose of this study was to determine whether concentrations of various blood cell types placed into a bridging extracellular matrix implant at the time of ACL repair would have a significant effect on the healing ligament cross-sectional area or tissue organization (as measured by signal intensity). We hypothesized that patients with higher physiologic platelet and lower WBC counts would have improved healing of the ACL on magnetic resonance imaging (MRI) (higher cross-sectional area and/or lower signal intensity) 6 months after surgery. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 61 patients underwent MRI at 6 months after bridge-enhanced ACL repair as part of the BEAR II trial. The normalized signal intensity and average cross-sectional area of the healing ligament were measured from a magnetic resonance stack obtained using a gradient echo sequence. The results were stratified by sex, and univariate and multivariate regression analyses determined significant correlations between blood cell concentrations on these 2 magnetic resonance parameters. Results: In unadjusted analyses, older age and male sex were associated with greater healing ligament cross-sectional area ( P < .04) but not signal intensity ( P > .15). Adjusted multivariable analyses indicated that in female patients, a higher monocyte concentration correlated with a higher ACL cross-sectional area (β = 1.01; P = .049). All other factors measured, including the physiologic concentration of platelets, neutrophils, lymphocytes, basophils, and immunoglobulin against bovine gelatin, were not significantly associated with either magnetic resonance parameter in either sex ( P > .05 for all). Conclusion: Although older age, male sex, and monocyte concentration in female patients were associated with greater healing ligament cross-sectional area, signal intensity of the healing ligament was independent of these factors. Physiologic platelet concentration did not have any significant effect on cross-sectional area or signal intensity of the healing ACL at 6 months after bridge-enhanced ACL repair in this cohort. Given these findings, factors other than the physiologic platelet concentration and total WBC concentration may be more important in the rate and amount of ACL healing after bridge-enhanced ACL repair.

Pelvic Canal Narrowing Caused by Triple Pelvic Osteotomy in the Dog

1994 ◽  
Vol 07 (03) ◽  
pp. 110-113 ◽  
Author(s):  
D. L. Holmberg ◽  
M. B. Hurtig ◽  
H. R. Sukhiani
Keyword(s):  
Postoperative Complications ◽  
Pelvic Osteotomy ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Canal Width ◽  
Operative Complications ◽  
Post Operative Complications

SummaryDuring a triple pelvic osteotomy, rotation of the free acetabular segment causes the pubic remnant on the acetabulum to rotate into the pelvic canal. The resulting narrowing may cause complications by impingement on the organs within the pelvic canal. Triple pelvic osteotomies were performed on ten cadaver pelves with pubic remnants equal to 0, 25, and 50% of the hemi-pubic length and angles of acetabular rotation of 20, 30, and 40 degrees. All combinations of pubic remnant lengths and angles of acetabular rotation caused a significant reduction in pelvic canal-width and cross-sectional area, when compared to the inact pelvis. Zero, 25, and 50% pubic remnants result in 15, 35, and 50% reductions in pelvic canal width respectively. Overrotation of the acetabulum should be avoided and the pubic remnant on the acetabular segment should be minimized to reduce postoperative complications due to pelvic canal narrowing.When performing triple pelvic osteotomies, the length of the pubic remnant on the acetabular segment and the angle of acetabular rotation both significantly narrow the pelvic canal. To reduce post-operative complications, due to narrowing of the pelvic canal, overrotation of the acetabulum should be avoided and the length of the pubic remnant should be minimized.

DETERMINATION OF THE FUNCTION OF THE ROD’S CROSS-SECTIONAL AREA USING VIBRATION EIGENFREQUENCIES

2020 ◽  
Vol 0 (4) ◽  
pp. 19-24
Author(s):  
I.M. UTYASHEV ◽  
◽  
A.A. AITBAEVA ◽  
A.A. YULMUKHAMETOV ◽  
◽  
...  
Keyword(s):  
Cross Sectional Area ◽  
Variable Cross ◽  
Sectional Area ◽  
Longitudinal Vibrations ◽  
Cross Sectional ◽  
Method Error ◽  
Various Boundary Conditions ◽  
Elastic Fixation ◽  
Crosssectional Area

The paper presents solutions to the direct and inverse problems on longitudinal vibrations of a rod with a variable cross-sectional area. The law of variation of the cross-sectional area is modeled as an exponential function of a polynomial of degree n . The method for reconstructing this function is based on representing the fundamental system of solutions of the direct problem in the form of a Maclaurin series in the variables x and λ. Examples of solutions for various section functions and various boundary conditions are given. It is shown that to recover n unknown coefficients of a polynomial, n eigenvalues are required, and the solution is dual. An unambiguous solution was obtained only for the case of elastic fixation at one of the rod’s ends. The numerical estimation of the method error was made using input data noise. It is shown that the error in finding the variable crosssectional area is less than 1% with the error in the eigenvalues of longitudinal vibrations not exceeding 0.0001.

Changes in the parameters of nasal breathing and parameters of the upper respiratory tract during orthognathic operations in patients with II and III skeletal class of jaw anomalies

2020 ◽  
pp. 22-27
Author(s):  
S.Sh. Gammadaeva ◽  
M.I. Misirkhanova ◽  
A.Yu. Drobyshev
Keyword(s):  
Respiratory Tract ◽  
Nasal Cavity ◽  
Nasal Septum ◽  
Cross Sectional Area ◽  
Upper Respiratory Tract ◽  
Sectional Area ◽  
Nasal Breathing ◽  
Cross Sectional ◽  
Skeletal Class ◽  
Upper Respiratory

The study analyzed the functional parameters of nasal breathing, linear parameters of the nasal aperture, nasal cavity and nasopharynx, volumetric parameters of the upper airways in patients with II and III skeletal class of jaw anomalies before and after orthognathic surgery. The respiratory function of the nose was assessed using a rhinomanometric complex. According to rhinoresistometry data, nasal resistance and hydraulic diameter were assessed. According to the data of acoustic rhinometry, the minimum cross-sectional area along the internal valve, the minimum cross-sectional area on the head of the inferior turbinate and nasal septum and related parameters were estimated. According to the CBCT data, the state of the nasal septum, the inferior turbinates, the nasal aperture, the state of the nasal cavity, and the linear values of the upper respiratory tract (nasopharynx) were analyzed. The patients were divided into 4 groups according to the classification of the patency of the nasal passages by

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