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Lateral Compartment (lateral + compartment)

Distribution by Scientific Domains

Medical Sciences	73%
Life Sciences	26%

Selected Abstracts

Effect of magnitude and direction of force on laryngeal abduction: Implications for the nerve-muscle pedicle graft technique

EQUINE VETERINARY JOURNAL, Issue 4 2009
P. CRAMP
Summary Reasons for performing study: The nerve-muscle pedicle graft technique is a treatment for recurrent laryngeal neuropathy (RLN), but the optimal placement of the pedicles within the cricoarytenoideus dorsalis (CAD) muscle is unknown. Hypothesis: The magnitude and direction of force placed on the muscular process of the left arytenoid cartilage affects the magnitude of laryngeal abduction. Methods: Five larynges were harvested from cadavers. Using increments of 0.98 N, a dead-weight force generator applied a force of 0,14.7 N for 1 min each to the left muscular process at 0, 10, 20, 30, 40, 50, 60 and 70° angles. The rima glottis was photographed digitally 1 min after each force had been applied. Distances between biomarkers (Lines 1,4) and right to left angle quotient (RLQ) were used to assess the degree of left arytenoid abduction. Results: Increasing force from 0,14.7 N progressively and significantly increased the length of all lines and RLQ, indicating abduction. Furthermore, there was a significant interaction between force and angles. Applying forces of 7.84 N or greater (Lines 2,4 and RLQ) or 11.76 N or greater (Line 1) at angles 0, 10, 20 and 30° resulted in significantly greater abduction than applying the same forces at 40, 50, 60 and 70°. Angles of 0,30° correspond with the direction of pull exerted by the lateral compartment of the CAD muscle. Conclusion: In RLN, nerve-muscle pedicle grafts should be placed preferentially in the lateral rather than in the medial compartment of the CAD muscle. Potential relevance: The information presented can be used to assist surgeons in the planning and application of the nerve-muscle pedicle graft procedure. [source]

Increased tibiofemoral cartilage contact deformation in patients with anterior cruciate ligament deficiency

ARTHRITIS & RHEUMATISM, Issue 12 2009
Samuel K. Van de Velde
Objective To investigate the in vivo cartilage contact biomechanics of the tibiofemoral joint following anterior cruciate ligament (ACL) injury. Methods Eight patients with an isolated ACL injury in 1 knee, with the contralateral side intact, participated in the study. Both knees were imaged using a specific magnetic resonance sequence to create 3-dimensional models of knee bone and cartilage. Next, each patient performed a lunge motion from 0° to 90° of flexion as images were recorded with a dual fluoroscopic system. The three-dimensional knee models and fluoroscopic images were used to reproduce the in vivo knee position at each flexion angle. With this series of knee models, the location of the tibiofemoral cartilage contact, size of the contact area, cartilage thickness at the contact area, and magnitude of the cartilage contact deformation were compared between intact and ACL-deficient knees. Results Rupture of the ACL changed the cartilage contact biomechanics between 0° and 60° of flexion in the medial compartment of the knee. Compared with the contralateral knee, the location of peak cartilage contact deformation on the tibial plateaus was more posterior and lateral, the contact area was smaller, the average cartilage thickness at the tibial cartilage contact area was thinner, and the resultant magnitude of cartilage contact deformation was increased. Similar changes were observed in the lateral compartment, with increased cartilage contact deformation from 0° to 30° of knee flexion in the presence of ACL deficiency. Conclusion ACL deficiency alters the in vivo cartilage contact biomechanics by shifting the contact location to smaller regions of thinner cartilage and by increasing the magnitude of the cartilage contact deformation. [source]

Trabecular morphometry by fractal signature analysis is a novel marker of osteoarthritis progression,

ARTHRITIS & RHEUMATISM, Issue 12 2009
Virginia Byers Kraus
Objective To evaluate the effectiveness of using subchondral bone texture observed on a radiograph taken at baseline to predict progression of knee osteoarthritis (OA) over a 3-year period. Methods A total of 138 participants in the Prediction of Osteoarthritis Progression study were evaluated at baseline and after 3 years. Fractal signature analysis (FSA) of the medial subchondral tibial plateau was performed on fixed flexion radiographs of 248 nonreplaced knees, using a commercially available software tool. OA progression was defined as a change in joint space narrowing (JSN) or osteophyte formation of 1 grade according to a standardized knee atlas. Statistical analysis of fractal signatures was performed using a new model based on correlating the overall shape of a fractal dimension curve with radius. Results Fractal signature of the medial tibial plateau at baseline was predictive of medial knee JSN progression (area under the curve [AUC] 0.75, of a receiver operating characteristic curve) but was not predictive of osteophyte formation or progression of JSN in the lateral compartment. Traditional covariates (age, sex, body mass index, knee pain), general bone mineral content, and joint space width at baseline were no more effective than random variables for predicting OA progression (AUC 0.52,0.58). The predictive model with maximum effectiveness combined fractal signature at baseline, knee alignment, traditional covariates, and bone mineral content (AUC 0.79). Conclusion We identified a prognostic marker of OA that is readily extracted from a plain radiograph using FSA. Although the method needs to be validated in a second cohort, our results indicate that the global shape approach to analyzing these data is a potentially efficient means of identifying individuals at risk of knee OA progression. [source]

Quadriceps strength and the risk of cartilage loss and symptom progression in knee osteoarthritis

ARTHRITIS & RHEUMATISM, Issue 1 2009
Shreyasee Amin
Objective To determine the effect of quadriceps strength in individuals with knee osteoarthritis (OA) on loss of cartilage at the tibiofemoral and patellofemoral joints (assessed by magnetic resonance imaging [MRI]) and on knee pain and function. Methods We studied 265 subjects (154 men and 111 women, mean ± SD age 67 ± 9 years) who met the American College of Rheumatology criteria for symptomatic knee OA and who were participating in a prospective, 30-month natural history study of knee OA. Quadriceps strength was measured at baseline, isokinetically, during concentric knee extension. MRI of the knee at baseline and at 15 and 30 months was used to assess cartilage loss at the tibiofemoral and patellofemoral joints, with medial and lateral compartments assessed separately. At baseline and at followup visits, knee pain was assessed using a visual analog scale, and physical function was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index. Results There was no association between quadriceps strength and cartilage loss at the tibiofemoral joint. Results were similar in malaligned knees. However, greater quadriceps strength was protective against cartilage loss at the lateral compartment of the patellofemoral joint (for highest versus lowest tertile of strength, odds ratio 0.4 [95% confidence interval 0.2, 0.9]). Those with greater quadriceps strength had less knee pain and better physical function over followup (P < 0.001). Conclusion Greater quadriceps strength had no influence on cartilage loss at the tibiofemoral joint, including in malaligned knees. We report for the first time that greater quadriceps strength protected against cartilage loss at the lateral compartment of the patellofemoral joint, a finding that requires confirmation. Subjects with greater quadriceps strength also had less knee pain and better physical function over followup. [source]

Tibial subchondral trabecular volumetric bone density in medial knee joint osteoarthritis using peripheral quantitative computed tomography technology

ARTHRITIS & RHEUMATISM, Issue 9 2008
Kim L. Bennell
Objective Knee osteoarthritis (OA) is an organ-level failure of the joint involving pathologic changes in articular cartilage and bone. This cross-sectional study compared apparent volumetric bone mineral density (vBMD) of proximal tibial subchondral trabecular bone in people with and without knee OA, using peripheral quantitative computed tomography (pQCT). Methods Seventy-five individuals with mild or moderate medial compartment knee OA and 41 asymptomatic controls were recruited. Peripheral QCT was used to measure vBMD of trabecular bone beneath medial and lateral tibiofemoral compartments at levels of 2% and 4% of tibial length, distal to the tibial plateau. Results There was no significant difference in vBMD beneath the overall medial and lateral compartments between the 3 groups. However, in the affected medial compartment of those with moderate OA, lower vBMD was seen in the 2 posterior subregions compared with controls and those with mild knee OA, while higher vBMD was seen in the anteromedial subregion. Beneath the unaffected or lesser affected lateral compartment, significantly lower vBMD was seen at the 2% level in the anterior and lateral subregions of those with moderate disease. Volumetric BMD ratios showed relatively higher vBMD in the medial compartment compared with the lateral compartment, but these ratios were not influenced by disease status. Conclusion Subregional vBMD changes were evident beneath the medial and lateral compartments of those with moderate medial knee OA. Of import, the posterior subchondral trabecular regions of the medial tibial plateau have markedly lower vBMD. [source]

Central bone marrow lesions in symptomatic knee osteoarthritis and their relationship to anterior cruciate ligament tears and cartilage loss

ARTHRITIS & RHEUMATISM, Issue 1 2008
Gabriela Hernández-Molina
Objective Medial and lateral compartment bone marrow lesions (BMLs) have been tied to cartilage loss. We undertook this study to assess 2 types of BMLs in the central region of the knee (type 1 BMLs, which are related anatomically to anterior cruciate ligament [ACL]/posterior cruciate ligament [PCL] insertions, and type 2 BMLs, which encompass both the central region and either the medial or the lateral compartment) and determine their relationship to cartilage loss and ACL tears. Methods Magnetic resonance imaging (MRI) of the knee was performed at baseline and at followup (15 and/or 30 months) in 258 subjects with symptomatic osteoarthritis (OA). At baseline, we assessed ACL tears and central BMLs located at or between the tibial spines or adjacent to the femoral notch. Cartilage loss was present if the score in any region of the tibiofemoral joint increased by ,1 units at the last available followup, using a modified Whole-Organ MRI Score. We used logistic regression adjusted for alignment, body mass index, Kellgren/Lawrence score, sex, and age. Results One hundred thirty-nine knees (53.8%) had central BMLs, of which 129 had type 1 BMLs (96 abutted the ACL and had no coexistent type 2 features) and 25 had type 2 BMLs (often overlapped with type 1). Type 1 lesions were associated with ACL tears (odds ratio [OR] 5.9, 95% confidence interval [95% CI] 2.2,16.2) but not with cartilage loss (OR 1.6, 95% CI 0.8,3.1), while medial type 2 BMLs were related to medial cartilage loss (OR 6.1, 95% CI 1.0,35.2). Conclusion Central BMLs that abutted the ACL were highly prevalent and strongly related to ACL pathology, suggesting a role of enthesopathy in OA. Only BMLs with medial extension were related to ipsilateral cartilage loss. [source]

Pretarsal fat compartment in the lower eyelid

CLINICAL ANATOMY, Issue 3 2001
Kun Hwang
Abstract It is generally accepted that there are three infraorbital fat regions in the lower eyelid; medial, central, and lateral compartments. However, removing only the fat in the lateral compartment does not remove the bulge just below the eyelashes, which is caused by another fat pad. The aim of this study was to describe the anatomy of the pretarsal fat compartment and to demonstrate its clinical implications in lower lid blepharoplasty. Ten cadavers (total 20 lower eyelids) were studied. A skin-muscle flap was reflected to expose the soft pretarsal structures. A small stab incision was made on the lateral portion of the sac containing fat on the tarsus. Methylene blue dye was injected into the sac. Specimens were fixed and sagittal sections in four different planes were prepared for histological analysis. The injected dye remained within the sac and demarcated it as a pear or cone shaped structure. This encapsulated fat compartment sits on the lateral half of the tarsal plate above the lateral compartment fat. Auxillary or submuscular fat is well known. This study, however, designates the pretarsal fat as "encapsulated" in a compartment instead of being unbound. We have named it the "pretarsal fat compartment." Histologically, orbital septal fibers separate "pretarsal fat" from lateral infraorbital fat. It is recommended that fat in the pretarsal fat compartment be removed during lower lid blepharoplasty in order to alleviate the bulge or knoll of the skin just below the lower eyelashes. Clin. Anat. 14:179,183, 2001. © 2001 Wiley-Liss, Inc. [source]

Transcervical superior mediastinal lymphadenectomy in the management of papillary thyroid carcinoma

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 1 2003
Mark L. C. Khoo FRCS
Abstract Aim. Surgery is the treatment of choice for lymph node metastases in papillary thyroid carcinoma. When adequately treated by surgical extirpation, the presence of lymph node involvement does not seem to have a negative impact on cure rates or survival. Surgical lymphadenectomy for metastatic papillary thyroid carcinoma has been well described for both the central and the lateral compartments of the neck. Superior mediastinal lymphadenectomy, however, has only sporadically been mentioned. We describe our experience with transcervical superior mediastinal lymphadenectomy (TSML) that avoids the morbidity of the traditional sternal split. Materials and Methods. This retrospective analysis included 30 patients (24 women and 6 men; age range, 17,72 years) who underwent TSML by the senior author (JLF) for papillary carcinoma metastatic to the superior mediastinum between 1985 and 1999. Histopathologic examination confirmed positive nodes in all the mediastinal dissections. All patients received postoperative I131. Results. All the patients are alive after a median follow-up of 5 years (range, 1,14 years). Twenty-nine of 30 patients remain free of disease, whereas one patient is alive with lung and bone metastases. No patient has had local or regional relapse. The only significant complication was a high incidence of temporary (70%) and later permanent (50%) hypoparathyroidism. Conclusions. TSML is a safe and effective treatment for superior mediastinal metastases in papillary thyroid carcinoma. © 2002 Wiley Periodicals, Inc. Head Neck 24: 000,000, 2002 [source]

Minute amounts of intraarticular gas mimicking torn discoid lateral menisci

JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 3 2010
Martin I. Jordanov MD
Abstract Presented are two cases of minute amounts of vacuum phenomena within the central portion of the lateral compartments of two knee joints, mimicking torn discoid lateral menisci. In each case, only the gradient echo images were able to correctly characterize the minute quantities of intraarticular gas by demonstrating "blooming" magnetic susceptibility artifact. The signal characteristics of the intraarticular gas were identical to those of fibrocartilage on all of the remaining routine, fast spin echo, "sports protocol" magnetic resonance imaging sequences. J. Magn. Reson. Imaging 2010;31:698,702. © 2010 Wiley-Liss, Inc. [source]

MicroCT evaluation of normal and osteoarthritic bone structure in human knee specimens

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 1 2003
Vikas Patel
Abstract Although trabecular bone structure has been evaluated, variation with knee compartment and depth from joint surface is not completely understood. Cadaver knees were evaluated with microcomputed tomography analysis for these variations. Objective differences were compared between: medial vs. lateral compartments; femoral vs. tibial bone; and normal vs. arthritic knees. Depth dependent changes in the parameters were observed for the first 6 mm of the cores in normal knees: BV/TV, Tb.N and Conn.D gradually decrease, while Tb.Sp and SMI increase. In the first 6 mm of the normal tibia BV/TV, Tb.N, and Tb.Th are greater than in the femur on both the medial and lateral compartments while Tb.Sp, SMI, and Conn.D are lower. The medial compartment values for BV/TV, Tb.N, Tb.Th and Conn.D are generally greater than for the lateral in both the femur and tibia while Tb.Sp and SMI are lower. In comparison of normal vs. arthritic knees significant differences are observed in the first 6 mm of the medial tibia. With arthritis BV/TV and Tb.Th are lower, while SMI and Tb.Sp are higher. Tb.N and Conn.D show no statistically significant difference. The bone structure variations are, thus, most prominent in the first 6 mm of depth and medial compartment bone is generally more structurally sound than lateral. Severely arthritic bone changes are most prominent in the medial compartment of the tibia and bone structure is less sound in severe arthritis. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source]