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PubMed1998

Elongation patterns of the collateral ligaments of the human knee.

OBJECTIVE: To determine the responses of the medial and lateral collateral ligaments (MCL, LCL) of the human knee to externally applied stresses. DESIGN: Differential variable reluctance transducers were used to measure length changes along the long posterior parallel fibers of the MCL and the middle third of the LCL through a flexion range of 15-120 degrees and a variety of external stresses. BACKGROUND: There is a lack of consensus regarding the collateral ligament response to internal and external tibial rotation. In addition, there are very few studies that have investigated the effects of quadriceps and hamstrings muscle group loads on the strain in the collateral ligaments. METHODS: Three series of tests were performed. First, the passive behavior of the ligaments was obtained as well as the ligament response to 3 degrees of varus and valgus rotation. The next series tested the ligaments' response to 0-10 degrees of internal and external tibial axial rotation. Finally, isolated and co-contracted quadriceps and hamstrings muscle group loads were applied. RESULTS: The instrumented portions of both ligaments were more strained in extension than flexion. Varus rotations stretched the LCL, whereas valgus rotations elongated the MCL. The strain in the MCL was shown to increase during external rotation and decrease during internal rotation. The LCL did not exhibit a uniform response across specimens to internal or external tibial axial rotation, but was consistent between left and right knees from a single cadaver. Highly consistent trends of interactions between muscle loads and the strain in both the MCL and LCL were noted. CONCLUSIONS: The responses of the MCL and LCL to applied stresses are dependent upon the flexion angle of the knee, the influence of muscle loading and, to a lesser extent, anatomic variation in the ligaments themselves. Guidelines for rehabilitation of the collateral ligaments following injury are suggested.

Journal Article↗
PubMed2003

Ultrasound screening in pregnancy: advancing technology, soft markers for fetal chromosomal aberrations, and unacknowledged ethical dilemmas.

Fetal ultrasound screening has become routine practice in many western countries. During the last decade, such screening has led to frequent situations characterised by clinical uncertainty due to the disclosure of soft markers in the unborn child. Soft markers are minor anatomical variations indicating a somewhat increased likelihood that the fetus has a chromosomal aberration, most frequently trisomy 21 (Down syndrome). This paper presents the results of a comprehensive literature search of the National Library of Medicine with emphasis on the chronological development of scientific knowledge in relation to soft markers and the link between advancing imaging technology and clinical counselling dilemmas. An analysis of the literature makes evident that many ultrasound examiners have counselled individual pregnant women on the basis of insufficient data. Moral dilemmas have thus emerged as a direct result of advancing medical technology, and healthy fetal lives prove to have been lost due to invasive diagnostic testing aimed at resolving clinical uncertainty. Ultrasound examiners have warned against a policy of disclosing all findings of soft markers to expectant parents, but no exploration of experiential aspects linked to the disclosure of fetal soft markers has yet been published in the medical literature. The emotional reactions of mothers are important to consider given their potential impact on the biological development of the fetus. In conclusion, this paper stresses the need for paying close attention to the crucial distinction between technology development and technology implementation in relation to prenatal testing. Furthermore, it provides strong arguments for scrutinising the interface between prenatal testing and human experience.

Biomarkers↗
PubMed1985

Facial nerve injury during surgery of the temporomandibular joint: a comparison of two dissection techniques.

Changing the dissection technique for gaining access to the temporomandibular joint decreased the incidence of facial nerve injury from 25% to 1.7%. This decrease can be attributed to the elimination of both development of a skin flap and dissection of tissue overlying the lateral capsule. Normal anatomic variation in the distribution of facial nerve branches may relate to the incidence of clinically apparent injury.

Dermatologic Surgical Procedures↗
PubMed1996

Anatomic disorders of the temporomandibular joint disc in asymptomatic subjects.

PURPOSE: This study determined the prevalence and specific anatomic types of disc displacement in asymptomatic versus symptomatic subjects using magnetic resonance imaging (MRI). PATIENTS AND METHODS: A detailed MRI assessment was performed on both temporomandibular joints (TMJ) in 76 volunteers and 102 successive patients. Attention was placed on the functional aspects of disc displacement with and without reduction and on the anatomic aspects of disc displacement in the anterior, lateral, medial, anterolateral, and anteromedial directions. These assessments were made by radiologists blinded to the clinical information. RESULTS: Disc displacement was found in at least one joint in 25 of 76 (33%) of asymptomatic subjects and 79 of 102 (77%) of symptomatic subjects. The anatomic types of disc displacement between groups was not statistically significant (P = .55). However, there was a significant difference between asymptomatic and symptomatic subjects, with an odds ratio of 3.91 for disc displacement with reduction and 42.71 for disc displacement without reduction (P < .001). CONCLUSION: Although there was a 33% prevalence of disc displacement in asymptomatic volunteers, there was a highly significant difference in the prevalence of internal derangement in symptomatic subjects. Bruxing was statistically linked to TMJ disc displacement and could explain the anatomic variation in abnormal disc position.

Adolescent↗
PubMed2002

[Constitutional anomalies of the terminal branches of the brachial plexus in the axial and brachial regions. Results of 42 cases and review of the literature].

The authors report anatomical variations of the terminal brachial plexus branches in 42 cadaveric dissections. The results are compared with results reported in literature which revealed a new variation: ulnar nerve originating in posterior beam. This study demonstrates that there exist not one but several brachial plexes which could have potential clinical implications.

Arm↗
PubMed1980

Selective conventional and xero-arteriography of the external carotid artery for control of intra-arterial chemotherapy.

The control of intra-arterial chemotherapy by selective conventional and xero-angiographic exploration of the external carotid artery is reported. With the aid of a catheter inserted into the superior thyroid, facial or super-facial temporal artery, all the main branches of the external carotid artery can be depicted. Xeroangiography in the area of the external carotid artery is a new method on which no data could be found in the literature. Anatomical variations of the vascular system and vascular lesions caused by surgery, a tumour, or intra-arterial chemotherapy are better demonstrated by xeroradiography. The bones and the soft parts are well depicted at the same time in the xeroradiographic pictures; thus the bony masses of the facial and petrous regions, together with the vessels on the bones, in the bones and in the soft parts are visible on one and the same picture.

Angiography↗
PubMed2001

Regional differences in the expression of corticostriatal synaptic plasticity.

Field recordings of responses to activation of corticostriatal afferents were made in coronally sectioned rat brain slices. Each recording site was categorized according to its medial to lateral and rostral to caudal position to investigate anatomical differences in synaptic plasticity. Individual responses were highly variable exhibiting extremes of tetanus induced depression and potentiation. Consequently, averaging masked the capacity of these synapses to express long-term forms of plasticity. Block of GABA(A) inhibition and elimination of dopaminergic input with 6-hydroxydopamine lesions both acted to increase the expression of potentiation, but again considerable variability was observed. Separation of recordings into medial and lateral groups revealed clear anatomical trends which contributed to the variability observed in the total sample. Paired-pulse, post-tetanic and long-term potentiation was greater in medial than in lateral groups in normal artificial cerebral spinal fluid. Similar tendencies were seen after block of GABA(A) receptors with bicuculline. 6-Hydroxydopamine lesions in combination with bicuculline treatment reduced medial to lateral differences. Factoring in medial to lateral trends revealed block of GABA(A) receptor mediated inhibition had its greatest effect on medial corticostriatal responses and 6-hydroxydopamine lesions had their greatest effect on lateral responses. From these data we suggest anatomical variation in striatal circuitry may underlie regional differences in synaptic plasticity evoked by corticostriatal activation.

Action Potentials↗
PubMed2000

Internal mammary node coverage: an investigation of presently accepted techniques.

PURPOSE: Recent publications have generated a renewed interest in regional nodal treatment to include the ipsilateral supraclavicular and internal mammary nodes (IMN). The purpose of this study is to evaluate three presently accepted treatment techniques for coverage of the intact breast and ipsilateral lymph node regions and to construct recommendations regarding the utilization of these techniques. METHODS AND MATERIALS: Anatomic data were obtained from five randomly selected patients with computerized tomography (CT) in treatment position. Three patients presented with cancer of the left breast and two with cancer of the right. Using the Pinnacle 3-D planning system, normal tissue volumes of breast, ipsilateral lung, heart, sternum, and the IMN target were delineated for each patient. Three accepted techniques used to treat ipsilateral breast, internal mammary and supraclavicular nodes (extended tangents, 5-field, partly wide tangents) were configured and compared to a supraclavicular field matched to standard tangential fields. A dosage of 50 Gy in 25 fractions was prescribed to the target volume. Dose-volume histograms (DVH) were generated and analyzed with regard to target volume coverage and lung/heart volumes treated. RESULTS: All of the treatment techniques covering IMN include at least 10% more lung and heart volume than that covered by standard tangential fields. The relative lung and heart volumes treated with each technique were consistent from patient to patient. The 5-field technique clearly treats the largest volume of normal tissue; however, most of this volume receives less than 50% of the dose prescribed. The percent of heart and ipsilateral lung treated to 20 Gy, 30 Gy, and 40 Gy have been calculated and compared. Due to the increase in chest wall thickness and depth of IMN superiorly, complete coverage was not achieved with any technique if the IMN target extended superiorly into the medial supraclavicular field where dose fall-off resulted in a significant underdosing at depth. For the same anatomic reasons, the 5-field technique underdosed 10-15% of the IMN target volume in 4 of the 5 cases. This technique also yielded a greater dose heterogeneity, which was not seen with the other techniques evaluated and correlated with the change of anterior chest wall thickness. CONCLUSIONS: Anatomic variation in chest wall thickness and IMN depth strongly suggests the routine use of multislice CT planning to ensure complete coverage of the target volume and optimal sparing of normal tissue. All of the techniques can be constructed to look acceptable at central axis. To cover the superior most aspect of the IMN chain either high tangential fields, a supraclavicular field photon beam of energy >6 MV, or an AP/PA supraclavicular setup should be considered. The 5-field technique has the most difficulty in compensating for the increased depth of the IMN in the superior aspect of the tangent fields with up to +/-40% variation of the dose noted in isolated areas within the target volume. Based on our evaluation, the partly wide tangent technique offers many advantages. It provides optimal coverage of the target volume, reduces coverage of normal tissue volumes to an acceptable level, and is easily reproducible with a high degree of dose homogeneity throughout the target.

Breast Neoplasms↗
PubMed1995

The first dorsal extensor compartment: an anatomic study.

Sixty-six cadaver hands were dissected to better define the anatomic variations of the first dorsal compartment and the superficial radial nerve. A septum was present in 31. A separate compartment enclosed the extensor pollicis brevis tendon in 29 and a slip of the abductor pollicis longus in 2. Multiple slips of the abductor pollicis longus tendon were noted in 38. Accessory slips inserted into the trapezium and thenar musculature. Partial separation or grooving of the abductor pollicis longus tendon was common but did not necessarily define a separate tendon slip.

Cadaver↗
PubMed1995

The musculocutaneous nerve and its branches to the biceps and brachialis muscles.

The musculocutaneous nerve and its motor branches to the biceps and brachialis were dissected and studied under the operating microscope in 24 fresh-frozen cadaveric specimens. The motor branch to the biceps exits from the musculocutaneous nerve at 119 mm distal to the coracoid process. Anatomic variations were seen in the innervation of the two heads of the biceps. A common primary motor branch that bifurcates to supply the two heads was seen in 20 specimens (type I). Two specimens were observed to have two separate primary branches originating from the main musculocutaneous nerve trunk to individually supply each head of the biceps (type II). The third variation, two specimens (type III), was observed in two specimens to be similar to type I, but with an additional distal motor branch innervating the common belly of the biceps muscle. The motor branch to the brachialis muscle exists from the musculocutaneous nerve 170 mm distal to the coracoid process. A single primary motor branch (type I) was seen in 23 specimens, and 1 specimen (type II) showed two separate primary motor branches innervating the muscle. The motor branches to the biceps and brachialis muscles may be dissected proximally from their points of exit from the main trunk of the musculocutaneous nerve for a mean distance of 44 mm and 53 mm, respectively. This information can be used by surgeons who elect to suture intercostal nerves to the motor branches of the biceps and brachialis muscles for elbow flexion in brachial plexus injuries.

Arm↗
PubMed1992

Tendon graft donor sites.

Each of 480 extremities from 120 cadavers was dissected. Particular attention was given to potential donors for tendon grafts. Both the palmaris longus and the extensor digiti minimi had an average length of 16 cm and an average width of 3 mm. The extensor indicis tendon averaged 13 cm in length and 3 mm in width. The plantaris and second toe extensors averaged 35 cm in length and 2 to 2.5 mm in width. None of these measurements correlated well with age, sex, or hand or foot size. There was, however, a high correlation between right- and left-side measurements in each specimen, in spite of some degree of anatomic variation for all the tendons studied. The palmaris longus was missing in 25% of the upper extremities, and the plantaris in 19% of the lower extremities dissected.

Adult↗
PubMed1991

Retrograde posterior interosseous flap.

A retrospective, continuous clinical series of 36 distally based posterior interosseous island flap procedures is reported. Major anatomic variations precluded the final dissection of the flap on two occasions (6%). Thirty-four patients had septocutaneous or septofascial flap coverage for treatment of acute complex injuries (12), subacute soft tissue defects (10), chronic ulcers (5), or contractures (7). The sizes of the flap islands varied from 1.5 by 4 centimeters to 9 by 11 centimeters. The arc of rotation, centered over the distal radioulnar joint, measured up to 19 centimeters, allowing the flaps to reach the dorsum of the proximal interphalangeal joints. Partial necrosis occurred in seven flaps; four (12%) required additional local or distant flaps. Partial failures were related to bleeding from the pedicle or compression thereof, while other assumed causes of hypoperfusion were not statistically relevant. The flaps remained slightly bulky in about 30% of the patients, but otherwise adapted well to the recipient site and had excellent texture and color match. The donor morbidity was minimal.

Adult↗
PubMed1988

Diagnosis of dorsal and palmar rotation of the lunate on a frontal radiograph.

Anatomic variations in the contours of the palmar and dorsal horns of 100 dry lunates were classified by symmetry, curvature, and angularity. Frequencies of the major forms were determined. An algorithm was constructed for the identification of the dorsal and palmar horns of the lunate on a frontal radiograph. By this algorithm, it is possible to diagnose intercalated segment instabilities without the use of a lateral radiograph.

Adult↗
PubMed1998

An anatomic study of the ligamentous structure of the triangular fibrocartilage complex.

An anatomic study of the ligamentous structures of the triangular fibrocartilage complex and their attachments on the ulnar styloid was performed using 27 embalmed cadaver wrists. The dorsal and palmar distal radioulnar ligaments of the triangular fibrocartilage complex in each specimen contained a superficial and a deep portion. The deep portion of both ligaments inserted on the fovea of the ulna. The superficial portion of both ligaments surrounded the articular disc uniting at the ulnar-most portion of the articular disc. The tissue that is between the ulnar aspect of the superficial ligament (and integrated on its periphery) and the ulnar capsule is defined as the meniscus homologue. Anatomic variations in the meniscus homologue and the prestyloid recess (the cavity adjacent to the ulnar styloid) were seen in 1 of 3 ways; the narrow opening type in 74% of specimens, the wide opening type in 11%, and the no opening type in 15%. The ulnotriquetral ligament inserted on the palmar-radial aspect of the base of the ulnar styloid and the ulnolunate ligament inserted on the palmar border of the articular disc.

Cadaver↗
PubMed1999

Effect of ovarian steroids and oxytocin on the production of prostaglandin E2, prostaglandin F2alpha and endothelin-1 from cow oviductal epithelial cell monolayers in vitro.

Cyclic physio-anatomical variation in the oviducts is mediated by the local countercurrent transfer of ovarian products. Thus, in this study cow oviductal epithelial cells (COEC) culture were utilized to investigate the effects of ovarian products such as progesterone (P4), estradiol 17beta (E2) and oxytocin (OT) on local oviductal prostaglandin E2 (PGE2), F2alpha (PGF2alpha) and endothelin-1 (ET-1) production. COEC were collected from non-pregnant Holstein cows (n = 8) during the follicular phase and cultured in M199 under standard culture conditions until monolayer formation. Cells in first passage were incubated for 24 or 48 h with P4 (500 ng/ml), E2 (1 ng/ml), OT (10(-9) M) or combination of E2 + P4. Administration of E2 significantly increased the production of PGE2, PGF2alpha and ET-1. However, simultaneous administration of P4 blocked the effect of E2. OT did not show any effect on oviductal productions of either PGs or ET-1. The results of this study show that E2 stimulates PG and ET-1 production by COEC in vitro. Thus, it can be suggested that locally transferred E2 from the ovarian follicles may be important for oviductal contraction and gamete/zygote transport during the peri-ovulatory period.

Animals↗
PubMed2001

Bilateral accessory anterior bellies of the digastric muscle and review of the literature.

OBJECTIVE: The aim of our paper is discussing anomalies of the anterior belly of the digastric muscle with presenting our case in light literature. METHODS: During dissection of the submental region of 26 years old Turkish female embedded cadaver, for this educational purpose in 2000, bilateral accessory digastric muscle was observed. RESULTS: The anterior and posterior bellies of the digastric muscle had their normal origin and course and were joined by an intermediate tendon, the accessory anterior bellies originated from the digastric fossa, and inserted to the hyoid bone, with a common fibrous band. The accessory anterior bellies of the digastric muscle were in the same shape and coursed parallel to each other. CONCLUSION: Anatomical variations of the anterior bellies of the digastric muscles can be easily confused with pathological conditions in CT and MR imaging, it is necessary to recognize that muscle variants of the digastric muscle occur to avoid confusion when diagnosing abnormal lesions of the floor of the mouth and submental region. In human body, such as these muscle variations have clinical significance.

Adult↗
PubMed2001

Pneumatization of the inferior turbinate.

Pneumatization of the inferior turbinate is an extremely rare intranasal anatomical variation. Only a few cases have been reported yet. In this paper we present two cases, one unilateral and one bilateral case with pneumatization of the inferior turbinate.

Adult↗