Insertion Area Research Articles

Insertion Area in the Mandible Masticatory Muscles for use in Finite Element Analyses

Para validar los resultados virtuales de analisis por elementos finitos (FEA) es necesario que los modelos matematicos consideren el area de insercion muscular. Asi, el objetivo de este estudio fue medir el area de insercion en la mandibula de los musculos de masticacion en cadaveres humanos para ser utilizado en FEA. El area de insercion en la mandibula de los musculos de masticacion fue medida en ambos lados de cincuenta cadaveres humanos por medio de fotografias digitales y software. El area de insercion del musculo masetero fue 7,47(±0,41) cm2, la porcion interna del musculo temporal fue de 3,05(±0,13) cm2 y su porcion externa de 2,25(±0,28) cm2, para los musculos pterigoideo medial fue de 2,2(±0,23) cm2 y pterigoideo lateral 0,8(±0,05) cm2. En conclusion, los datos son suficientes para ser utilizados para analisis de elementos finitos.

Morpho-functional analysis of the mastoid region of the extinct South American mustelid †Stipanicicia pettorutii

ABSTRACTThe morphology of the mastoid region in predators is informative about the hunting strategies and capacity of carrying prey. The purpose of this research was to describe the mastoid region and reconstruct the associated musculature of †Stipanicicia pettorutii Reig, 1956, a Pleistocene weasel with a distinctive morphology compared to its living relatives, and to make inferences about its predatory abilities. Galictis, a living weasel closely related to Stipanicicia, as well as other carnivorans, were used as comparative models. The muscle insertions identified in Stipanicicia presented a similar or larger development than Galictis. The insertion area of the muscles obliquus capitis cranialis, longissimus capitis, sternocephalicus pars mastoidea and cleidocephalicus pars mastoidea were found to be markedly developed and in a lateralised position with respect to the atlanto–occipital joint in hyaenids and mustelids, and especially in Stipanicicia, suggesting powerful lateral flexion and rotation movements in the fossil. The larger degree of advancement of the mastoid process in mustelids, and secondary in felids, would allow a powerful ventral flexion of the head. Stipanicicia would have exhibited powerful lateral movements and retraction of the head and neck, over restricted extension movements and, therefore, would have been a weasel specialised in subjugating and carrying prey of a relatively large size.

An anatomic study of the attachments on the condylar process of the mandible: muscle bundles from the temporalis.

The aim of this study was to evaluate anatomically the relationship between bone and muscles by detailed observation of the bone shape and the structure of muscles to facilitate an understanding of the function of the muscles involved in jaw movement. 36 specimens of 24 Japanese cadavers were examined. The insertion areas were marked using a radiopaque marker and examined by micro-computed tomography. For morphological observation, we used 101 condylar processes. In addition, we made histological sections in some specimens to observe the detailed attachments of the muscle. Based on the micro-CT images and dissection findings, the lateral pterygoid muscle was found to be most frequently inserted into the anterior impression and attached to the medial impression of the process. According to the histological observations, the lateral pterygoid muscle mainly inserted to the condylar process. The micro-CT images indicated that the obvious bony ridge was lateral to the pterygoid fovea on the condylar process in all specimens. The midmedial muscle bundle of the temporalis was attached to the ridge. Based on the morphological observations, the ridge was situated on the lateral area of the condylar process. Since dysfunction of the temporomandibular joint is likely closely related to both the lateral pterygoid muscle and also the temporalis, further studies are necessary to evaluate the function of these muscles and consider jaw movement.

The Accuracy of the Lateral Tibial Spine as a Landmark for Lateral Meniscal Allograft Transplantation

To determine a relationship between the direction of the guide pin for the keyhole in the lateral meniscus (LM) transplantation and the line connecting the centers of both horns of the LM. Forty-four resected tibial plateaus during total knee arthroplasty were used for anatomical and radiological evaluations. The inclusion criterion was medial compartment osteoarthritis. Exclusion criteria were osteoarthritic changes, meniscal tear, and previous fracture in the lateral compartment. Resected tibial plateaus were positioned so that the anterior and posterior parts of the lateral tibial spine (LTS) were overlapped accurately on fluoroscopic anteroposterior view. A wire (Pin-F) was drilled along the peak of the LTS. The insertion area of anterior and posterior horns of the LM was dissected carefully. The periphery and the center of the insertion area of both horns were marked. Another wire (Pin-A) was drilled along a line connecting the centers of both horns. An axial radiograph was taken for each prepared tibial plateau. A longitudinal line was drawn along each wire, and the angle between the 2 wires was measured using the imaging software. If the Pin-F was externally rotated relative to the Pin-A, the angle was designated as positive, and if the Pin-F was internally rotated, the angle was designated as negative. The mean angle between Pin-F and Pin-A was -7.4° ± 9.6°. Thirty-three (75%) Pin-Fs were fixed in an internally rotated position, and 11 (25%) were fixed in an externally rotated position. The direction of most guide pins drilled along the LTS was not coincident with the line connecting the centers of both horns of the LM. The axis of the LTS is not a reliable marker for the trough in the LM allograft transplantation.

Elastic band ligation for the removal of a colonic tubular adenoma in a diverticulum

A 56-year-old healthy patient underwent colonoscopy after a positive fecal occult blood test result. This examination showed diverticulosis of the left side of the colon and, at 20cm from the anal verge, a 6-mm sessile polyp in the neck of a diverticulum with intradiverticular extension (● Fig.1a). Narrow-band imaging showed a large tubular pit pattern: Kudo type III-L (● Fig.1b). Using a gastroscope (GIF-Q165; Olympus, Tokyo, Japan) with a conventional band ligator device (Speedband Superview Super; Boston Scientific, Natick, Massachusetts, USA) attached to the tip, we positioned the diverticular orifice and the polyp in the center of the cap. The diverticulum (including the insertion area of the polyp) was then suctioned and partially inverted into the cap of the endoscopic ligator, and an elastic band was released around its neck (● Video 1). The polyp was visible on the top of the inverted diverticulum (● Fig.2). Colonic tattooing was performed. As a result of ischemia, necrosis, and cicatrization of the underlying tissues, the elastic band contents fell off in a few days [1]. Endoscopic evaluation 2 weeks later showed a residual diverticulum adjacent to the tattoo. A cicatricial area was identified on the neck of the residual diverticulum, with no evidence of residual adenoma (● Fig.3). Colonic diverticula do not have a muscular layer, so there is a high risk for perforation when a standard snare excision technique is used for polyps extending into diverticula. Elastic banding has recently been shown to be safe and highly effective in diverticular bleeding [2]. It appears that this technique may also be safe and effective for the resection of a colonic adenoma extending into a diverticulum [3]. It is also minimally invasive, so that perforation and the need to perform laparoscopy or apply an over-the-scope-clip to close it can be avoided [4,5]. However, no specimen is obtained for histopathological analysis, which probably limits the size and the pit pattern of the polyps in which this technique should be used.

Body surface infrared thermometry in patients with central venous cateter-related infections

Objective To evaluate if body surface temperature close to the central venous catheter insertion area is different when patients develop catheter-related bloodstream infections.Methods Observational cross-sectional study. Using a non-contact infrared thermometer, 3 consecutive measurements of body surface temperature were collected from 39 patients with central venous catheter on the following sites: nearby the catheter insertion area or totally implantable catheter reservoir, the equivalent contralateral region (without catheter), and forehead of the same subject.Results A total of 323 observations were collected. Respectively, both in male and female patients, disregarding the occurrence of infection, the mean temperature on the catheter area minus that on the contralateral region (mean ± standard deviation: -0.3±0.6°C versus -0.2±0.5ºC; p=0.36), and the mean temperature on the catheter area minus that on the forehead (mean ± standard deviation: -0.2±0.5°C versus -0.1±0.5ºC; p=0.3) resulted in negative values. Moreover, in infected patients, higher values were obtained on the catheter area (95%CI: 36.6-37.5ºC versus 36.3-36.5ºC; p<0.01) and by temperature subtractions: catheter area minus contralateral region (95%CI: -0.17 - +0.33ºC versus -0.33 - -0.20ºC; p=0.02) and catheter area minus forehead (95%CI: -0.02 - +0.55ºC versus -0.22 - -0.10ºC; p<0.01).Conclusion Using a non-contact infrared thermometer, patients with catheter-related bloodstream infections had higher temperature values both around catheter insertion area and in the subtraction of the temperatures on the contralateral and forehead regions from those on the catheter area.

Effect of partial-thickness tear on loading capacities of the supraspinatus tendon: a finite element analysis

Partial-thickness tears of the supraspinatus tendon frequently occur at its insertion on the greater tubercule of the humerus, causing pain and reduced strength and range of motion. The goal of this work was to quantify the loss of loading capacity due to tendon tears at the insertion area. A finite element model of the supraspinatus tendon was developed using in vivo magnetic resonance images data. The tendon was represented by an anisotropic hyperelastic constitutive law identified with experimental measurements. A failure criterion was proposed and calibrated with experimental data. A partial-thickness tear was gradually increased, starting from the deep articular-sided fibres. For different values of tendon tear thickness, the tendon was mechanically loaded up to failure. The numerical model predicted a loss in loading capacity of the tendon as the tear thickness progressed. Tendon failure was more likely when the tendon tear exceeded 20%. The predictions of the model were consistent with experimental studies. Partial-thickness tears below 40% tear are sufficiently stable to persist physiotherapeutic exercises. Above 60% tear surgery should be considered to restore shoulder strength.

Mandibular, hyoid and pectoral musculature of thorny catfishes (Siluriformes: Doradidae)

ABSTRACT. This paper reports the results of a comparative study of the mandibular, hyoid, and pectoral musculature of South American Doradidae. Sixty-one species of Doradidae were examined including representatives of all the genera. Twenty muscles are described including their ontogenetic origin, function, area of origin and insertion, and parts. Seven muscles from the cranial region: adductor mandibulae, extensor tentaculi, levator arcus palatini, dilatator operculi, levator operculi, adductor operculi, and adductor arcus palatini; six muscles from the ventral region: intermandibularis, protractor hyoidei, hyohyoides inferioris, hyohyoidei abductores, hyohyoidei adductores, and sternohyoideus; and seven muscles from the pectoral fin: adductor superficialis, adductor profundus, abductor superficialis, abductor profundus, arrector ventralis, arrector dorsalis, and abductor rotator. Comparisons between Doradidae and other catfish families (e.g. Auchenipteridae, Aspredinidae) were made in order to understan...

Behavior of the anterolateral structures of the knee during internal rotation

IntroductionSince the recent descriptions of the anterolateral ligament (ALL), the role played by the anterolateral peripheral structures in the rotational control of the knee is again being debated. The objective of this study was to identify the structures during internal tibial rotation and then to define their anatomical characteristics. We hypothesized that internal rotation would tighten several anatomical formations, both superficial and deep, with the ALL one part of these structures. Material and methodsNine fresh-frozen cadaver knee specimens were studied. The anterolateral structures tightened were identified from superficial to deep at 30° of flexion. Each was selectively dissected, identifying its insertions and orientations, and measuring its size. The length variations of the ALL during internal tibial rotation were measured by applying a 30-N force using a dynamometric torque wrench at the tibiofibular mortise. ResultsThe superficial structures tightened were the iliotibial tract and the Kaplan fibers. In internal tibial rotation, the Kaplan fibers held the iliotibial tract against the lateral epicondyle, allowing it to play the role of a stabilizing ligament. The Kaplan fibers were 73.11±19.09mm long (range, 63–82mm) and at their femoral insertion they were 12.1±1.61mm wide (range, 10–15mm). The deep structures tightened covered a triangular area including the ALL and the anterolateral capsule. The ALL was 39.11±3.4mm long (range, 35–46mm) in neutral rotation and 49.88±5.3mm long (range, 42–58mm) in internal rotation (p<0.005). Its femoral insertion area was narrow at 5.27±1.06mm (range, 3.5–7mm) and was mainly proximal and posterior at the lateral epicondyle. Its tibial insertion zone was wide, with a clearly differentiated anterior limit but a posterior limit confused with the joint capsule. In the vertical plane, this insertion was located 6.44±2.37mm (range, 2–9) below the joint space. DiscussionThis study demonstrates two distinct anterolateral tissue planes tightened during internal rotation of the tibia: a superficial plane represented by the iliotibial tract and the Kaplan fibers, which acts as a ligament structure, and a deep plane represented by a triangular capsular ligament complex within which the ALL and the anterolateral capsule are recruited. Level of evidenceDescriptive cadaver study IV.

Recognizing upper-extremity stress lesions.

Athletes in sports such as baseball, gymnastics, weight lifting, javelin, and racket sports are susceptible to stress lesions in the bones of the upper extremities. Injuries range from periostitis to bone spurs to stress fractures. Injuries in adolescents typically involve the growth plates, while midshaft injuries at the area of muscle insertion are more common in adults. It's especially important to detect these injuries in adolescents because untreated stress lesions at growth plates can have serious consequences. Plain films demonstrate obvious fractures and physeal injuries, but triple-phase bone scans are often needed to define the extent of stress lesions.

Seamless Insertion of Pulmonary Nodules in Chest CT Images.

The availability of large medical image datasets is critical in many applications, such as training and testing of computer-aided diagnosis systems, evaluation of segmentation algorithms, and conducting perceptual studies. However, collection of data and establishment of ground truth for medical images are both costly and difficult. To address this problem, we are developing an image blending tool that allows users to modify or supplement existing datasets by seamlessly inserting a lesion extracted from a source image into a target image. In this study, we focus on the application of this tool to pulmonary nodules in chest CT exams. We minimize the impact of user skill on the perceived quality of the composite image by limiting user involvement to two simple steps: the user first draws a casual boundary around a nodule in the source, and, then, selects the center of desired insertion area in the target. We demonstrate the performance of our system on clinical samples, and report the results of a reader study evaluating the realism of inserted nodules compared to clinical nodules. We further evaluate our image blending techniques using phantoms simulated under different noise levels and reconstruction filters. Specifically, we compute the area under the ROC curve of the Hotelling observer (HO) and noise power spectrum of regions of interest enclosing native and inserted nodules, and compare the detectability, noise texture, and noise magnitude of inserted and native nodules. Our results indicate the viability of our approach for insertion of pulmonary nodules in clinical CT images.

Fluoroscopic control allows for precise tunnel positioning in MPFL reconstruction.

In MPFL reconstruction, anatomical graft positioning is required to restore physiological joint biomechanics and patellofemoral stability. Considerable rates of non-anatomical femoral tunnel placement exist. The purpose of this study was to analyse whether intraoperative fluoroscopic control is applicable to reduce variability of femoral tunnel positioning. Femoral tunnel positions of 116 consecutive MPFL reconstructions applying intraoperative fluoroscopic images were analysed. Tunnel positions were determined by two independent observers according to Schöttle's radiographic measurement method. Mean positions, standard deviations and ranges were calculated to determine the variability of the tunnel positions. Interclass correlation coefficient (ICC) was calculated. The mean anterior/posterior distances from the anatomical insertion of the MPFL to the centre of the femoral tunnel were 2.34mm (range 0.0-5.9mm) and 1.7mm (range 0.1-7.3mm, SD 1.3) for proximal/distal deviations; 95.7% (111/116) of femoral tunnel positions were found to be within the anatomical insertion area defined by Schöttle. Interobserver tunnel position measurements were highly reliable (ICC: depth 0.979; height 0.979). The study demonstrates that intraoperative fluoroscopic control is a feasible and effective method that enables to create reproducible and precise anatomical femoral tunnel positions in MPFL reconstruction. Accordingly, the routine use of intraoperative fluoroscopy can be recommended. Furthermore, the results indicate Schöttle's method as a reliable method for intraoperative control and postoperative analysis of femoral tunnel positioning. IV.

Significance of Late Gadolinium Enhancement at Right Ventricular Attachment to Ventricular Septum in Patients With Hypertrophic Cardiomyopathy

Cardiovascular magnetic resonance (CMR) with extensive late gadolinium enhancement (LGE) is a novel marker for increased risk for sudden death (SD) in patients with hypertrophic cardiomyopathy (HC). Small focal areas of LGE confined to the region of right ventricular (RV) insertion to ventricular septum (VS) have emerged as a frequent and highly visible CMR imaging pattern of uncertain significance. The aim of this study was to evaluate the prognostic significance of LGE confined to the RV insertion area in patients with HC. CMR was performed in 1,293 consecutive patients with HC from 7 HC centers, followed for 3.4 ± 1.7 years. Of 1,293 patients (47 ± 14 years), 134 (10%) had LGE present only in the anterior and/or inferior areas of the RV insertion to VS, occupying 3.7 ± 2.9% of left ventricular myocardium. Neither the presence nor extent of LGE in these isolated areas was a predictor of adverse HC-related risk, including SD (adjusted hazard ratio 0.82, 95% confidence interval 0.45 to 1.50, p = 0.53; adjusted hazard ratio 1.16/10% increase in LGE, 95% confidence interval 0.29 to 4.65, p = 0.83, respectively). Histopathology in 20 HC hearts show the insertion areas of RV attachment to be composed of a greatly expanded extracellular space characterized predominantly by interstitial-type fibrosis and interspersed disorganized myocyte patterns and architecture. In conclusion, LGE confined to the insertion areas of RV to VS was associated with low risk of adverse events (including SD). Gadolinium pooling in this region of the left ventricle does not reflect myocyte death and repair with replacement fibrosis or scarring.

Restoration of the anatomic position during a meniscal allograft transplantation using pre-existing landmarks.

Accurate sizing and positioning of a meniscal allograft is an important factor for successful outcomes of meniscal allograft transplantation. The objectives of this study were (1) to search a proper rotational landmark, (2) to determine the sagittal slope of meniscus, and, thus (3) to determine the meniscal positioning. A total of 121 consecutive patients who underwent magnetic resonance imaging in the 3months prior to the beginning of the study were selected. To assess the meniscal rotation, rotation 0° line of the meniscus was defined as a line connecting the center of the anterior and the posterior horn of the medial and lateral meniscus, respectively. At this level, four possible reference lines were compared: Akagi line, line perpendicular to the largest mediolateral dimension (LMLD), line between the medial border of the patellar tendon and the apex of the medial tibial spine (PTMS), and line between the lateral border of the patellar tendon and the apex of the lateral tibial spine. To assess the meniscal slope, the slope of the insertional area, meniscal and bony slopes at the mid-plateau area were compared. Akagi line was significantly different with a true meniscal rotation (line connecting between centers of the anterior and posterior horns) in both medial and lateral meniscus (p<0.01 and p<0.01). LMLD was significantly different in the lateral meniscus (p<0.01), however, no statistical difference was observed in the medial meniscus (n.s.). PTMS was not different in the medial meniscus (n.s.), however, it was different in the lateral meniscus (p<0.01). On the medial side, significant statistical difference was observed between insertional and bony slope (p<0.01) and between meniscal and bony slope (p<0.01). On the lateral side, comparison of three slopes showed significant statistical differences (p<0.01-p=0.03). Line between patellar tendon and tibial spine was a good reference line for a meniscal rotation in the medial meniscus. Among previously introduced reference lines, LMLD showed approximity with a true meniscal rotation. The slope between tibial insertion and mid-portion was significantly different in the lateral meniscus.

Histological analysis of the structural composition of ankle ligaments.

Various ankle ligaments have different structural composition. The aim of this study was to analyze the morphological structure of ankle ligaments to further understand their function in ankle stability. One hundred forty ligaments from 10 fresh-frozen cadaver ankle joints were dissected: the calcaneofibular, anterior, and posterior talofibular ligaments; the inferior extensor retinaculum, the talocalcaneal oblique ligament, the canalis tarsi ligament; the deltoid ligament; and the anterior tibiofibular ligament. Hematoxylin-eosin and Elastica van Gieson stains were used for determination of tissue morphology. Three different morphological compositions were identified: dense, mixed, and interlaced compositions. Densely packed ligaments, characterized by parallel bundles of collagen, were primarily seen in the lateral region, the canalis tarsi, and the anterior tibiofibular ligaments. Ligaments with mixed tight and loose parallel bundles of collagenous connective tissue were mainly found in the inferior extensor retinaculum and talocalcaneal oblique ligament. Densely packed and fiber-rich interlacing collagen was primarily seen in the areas of ligament insertion into bone of the deltoid ligament. Ligaments of the lateral region, the canalis tarsi, and the anterior tibiofibular ligaments have tightly packed, parallel collagen bundles and thus can resist high tensile forces. The mixed tight and loose, parallel oriented collagenous connective tissue of the inferior extensor retinaculum and the talocalcaneal oblique ligament support the dynamic positioning of the foot on the ground. The interlacing collagen bundles seen at the insertion of the deltoid ligament suggest that these insertion areas are susceptible to tension in a multitude of directions. The morphology and mechanical properties of ankle ligaments may provide an understanding of their response to the loads to which they are subjected.

Gastroschisis: A case report

We are showing this event aimed to highlight the potential for gastroschisis at older mothers over 40 years and not only mothers younger population. The patient M. M, born in 1965, married in 41.years life diagnosed with uterine fibroids two. Three months after her marriage comes naturally to pregnancy. Sonographic findings: One fetus, pelvic presentation, amniotic fluid is optimal in the neck visibly thickened (accentuated nuchal traslucencija), BPD 25 mm, AC 84 mm, 14 mm FL, heart (-) NG / KL 15.2, NG / ultrasound 14.0, the placenta is embedded in the front wall of the uterus contraction. After careful observation in the area of insertion of the umbilical cord can be observed intestinal convolutions freely floating in the amniotic fluid. Grav.ml III IV.HBD ½ -15 / 16.FMU. Anomalies foeti obs. Gastroshizis obs. Uterus myomatosus. Consultative decided to terminate the pregnancy GAO HC Novi Pazar. Ekstrahovana Bed, underwent explorative curettage and administered terapija. Fetus a whole with the umbilical cord and placenta sent to PH review. For three weeks the PH finding confirmed gastroschisis and miltipne anomalies. The paper describes the case female patient 41 years old, first pregnancy, in which the early second trimester of fetal gastroschisis diagnosed with absence of fetal heart rate. Pregnancy is consultative decision interrupted without complications.

Aging-related changes in the skulls of Japanese macaques (&lt;i&gt;Macaca fuscata&lt;/i&gt;)

We investigated aging-related changes in the skulls of Japanese macaques (Macaca fuscata). A total of 145 (70 males, 75 females) skulls from macaques aged 7.0–26.9 years (males) and 7.0–30.7 years (females) were measured for 22 craniometric items. Some skull dimensions increased from young adulthood (7.0 years) to the peak at 13.3–19.0 years in males and at 19.7–22.6 years in females. Some dimensions remained at their peak value right through into very old age whereas others continued increasing during this stage of life. Continued increase of cranial size in adulthood has been also observed in humans, but the magnitude of change was greater in macaques. Facial and mandibular dimensions showed larger and more significant increases than neurocranial dimensions in macaques, as in humans, including facial height, bizygomatic breadth, mandibular body height, and ramus breadth in both sexes. Intertemporal distance and biorbital breadths after 16.0 years of age decreased significantly in males, and cranial and posterior basicranial lengths increased only in males. We suggest that these craniometric changes are associated with the development of the insertion area onto which muscles attach (by accumulation of physical stress). The face and mandible are greatly influenced by tooth loss and/or dental disorders, both of which are evident in humans. In the present study large changes were also found in skulls that had lost several teeth.

Anatomy of the Flexor Digitorum Profundus Insertion

To describe the anatomical insertion of the flexor digitorum profundus (FDP) on the distal phalanx. The FDP insertion to the index, middle, ring, and little fingers were dissected in 10 fresh-frozen cadavers. The FDP tendon was dissected off the volar plate, which was elevated from proximal to distal, before the distal phalanx was disarticulated. The distal phalanx was then inked and the FDP was sharply dissected from bone. The insertion length, width, and distance of the insertion from the joint were measured and the insertion surface area and centroid of the FDP insertion were calculated. The average insertion length and width were 6.2 mm (range, 5.1-7.0 mm) and 7.9 mm (range, 6.9-8.4 mm), respectively. The average surface area of the distal phalanx occupied by the FDP tendon, for all fingers, was 20% (range, 15%-27%). The average distance from the most proximal insertion to the joint surface was 1.2 mm (range, 0.4-2.1 mm) and the calculated centroid of the FDP insertion from the distal interphalangeal joint was 3.6 mm (range, 2.5-5.1 mm) or approximately 20% of the distal phalangeal length. These findings may aid anatomical attachment of the FDP tendon in the treatment of zone I injuries. A better understanding of the anatomy of the FDP insertion may aid proper repair positioning in the treatment of zone I injuries.

Length Change Patterns in the Lateral Extra-articular Structures of the Knee and Related Reconstructions

Background: Lateral extra-articular soft tissue reconstructions in the knee may be used as a combined procedure in revision anterior cruciate ligament surgery as well as in primary treatment for patients who demonstrate excessive anterolateral rotatory instability. Only a few studies examining length change patterns and isometry in lateral extra-articular reconstructions have been published. Purpose: To determine a recommended femoral insertion area and graft path for lateral extra-articular reconstructions by measuring length change patterns through a range of knee flexion angles of several combinations of tibial and femoral insertion points on the lateral side of the knee. Study Design: Controlled laboratory study. Methods: Eight fresh-frozen cadaveric knees were freed of skin and subcutaneous fat. The knee was then mounted in a kinematics rig that loaded the quadriceps muscles and simulated open-chain knee flexion. The length changes of several combinations of tibiofemoral points were measured at knee flexion angles between 0° and 90° by use of linear variable displacement transducers. The changes in length relative to the 0° measurement were recorded. Results: The anterior fiber region of the iliotibial tract displayed a significantly different (P < .001) length change pattern compared with the posterior fiber region. The reconstructions that had a femoral insertion site located proximal to the lateral epicondyle and with the grafts passed deep to the lateral collateral ligament displayed similar length change patterns to each other, with small length increases during knee extension. These reconstructions also showed a significantly lower total strain range compared with the reconstruction located anterior to the epicondyle (P < .001). Conclusion: These findings show that the selection of graft attachment points and graft course affects length change pattern during knee flexion. A graft attached proximal to the lateral femoral epicondyle and running deep to the lateral collateral ligament will provide desirable graft behavior, such that it will not suffer excessive tightening or slackening during knee motion. Clinical Relevance: These results provide a surgical rationale for lateral extra-articular soft tissue reconstruction in terms of femoral graft fixation site and graft route.

Methicillin-resistant Staphylococcus aureus: site of acquisition and strain variation in high-risk nursing home residents with indwelling devices.

Characterize the clinical and molecular epidemiology of new methicillin-resistant Staphylococcus aureus (MRSA) acquisitions at nasal and extranasal sites among high-risk nursing home (NH) residents. Multicenter prospective observational study. Six NHs in southeast Michigan. A total of 120 NH residents with an indwelling device (feeding tube and/or urinary catheter). Active surveillance cultures from the nares, oropharynx, groin, perianal area, wounds (if present), and device insertion site(s) were collected upon enrollment, at day 14, and monthly thereafter. Pulsed-field gel electrophoresis and polymerase chain reaction for SCCmec, agr, and Panton-Valentine leukocidin were performed. Of 120 participants observed for 16,290 device-days, 50 acquired MRSA (78% transiently, 22% persistently). New MRSA acquisitions were common in extranasal sites, particularly at device insertion, groin, and perianal areas (27%, 23%, and 17.6% of all acquisitions, respectively). Screening extranasal sites greatly increases the detection of MRSA colonization (100% of persistent carriers and 97.4% of transient carriers detected with nares, groin, perianal, and device site sampling vs 54.5% and 25.6%, respectively, for nares samples alone). Colonization at suprapubic urinary catheter sites generally persisted. Healthcare-associated MRSA (USA100 and USA100 variants) were the dominant strains (79.3% of all new acquisition isolates). Strain diversity was more common in transient carriers, including acquisition of USA500 and USA300 strains. Indwelling device insertion sites as well as the groin and perianal area are important sites of new MRSA acquisitions in NH residents and play a role in the persistency of MRSA carriage. Clonal types differ among persistent and transient colonizers.