Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SCAPULA”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 991 records · Page 55Linked to original sources
PubMed2006

The shape of the inferior part of the glenoid: a cadaveric study.

Previously, the shape of the inferior glenoid has been described as a circle with a bare spot being the center of that circle. This cadaveric study was done to test that statement. Forty cadaveric scapulae were used in this study. Two researchers used a digital image analysis program to assess the shape of the inferior glenoid and measured the distances from the bare spot to the anterior, inferior, and posterior cartilage and the bone rim. In 39 of 40 scapulae, the inferior glenoid had the shape of a true circle. Statistical analysis showed that the center of the bare spot is not the mathematical center of the inferior glenoid, but the differences in distances to the anterior, inferior, and posterior rims were very small (1.16-2.41 mm). Both observations can be used for further development of methods for measuring glenoid bone loss in patients with anterior glenohumeral instability.

Adult↗
PubMed1993

Osseous free flaps for orbit and midface reconstruction.

Osseous free flaps were used for reconstruction of the orbit and midface in 10 patients. The reconstruction was done at the time of tumor resection in two patients (20%) and secondarily in eight patients (80%). Nine patients (90%) had previously received radiotherapy. The flaps used were fibula (four), radial forearm (two), scapula (two), and split iliac crest (two). Flap loss occurred in one patient. Complications occurred in 2 of 10 (20%) patients. The results were classified as good in seven patients, fair in two, and poor in one. The patient classified as having a poor result was the one who sustained the flap loss; he refused further surgery. Reconstruction was directed to the maxilla in five patients, the orbit in two, and both in three. The radial forearm flap was best used for orbit-only reconstruction because of the small amount of bone required. The fibula, iliac crest, and scapula were best used for larger defects involving the maxilla. Osseointegrated dental implants were used successfully in three patients. Osseous free flaps are indicated for midface reconstruction when bony support is needed and previous irradiation prevents the use of nonvascularized grafts.

Adolescent↗
PubMed2002

Waking cervical pain and stiffness, headache, scapular or arm pain: gender and age effects.

A random population-based study using a structured telephone questionnaire was undertaken to determine the frequency, duration and prevalence of waking cervical spine pain and stiffness, headache, and aching between the scapulae or in the arm and their relationship to age and gender. Seventy-six per cent of households contacted completed the questionnaire, yielding a total of 812 questionnaires. Subjects most commonly reported waking with scapular or arm pain (27%) followed by headache (19%), cervical pain (18%) and cervical stiffness (17%). The majority of subjects reported that symptoms lasted for more than an hour on one or two occasions during the week. Subjects who reported the presence of one type of waking symptom were significantly more likely to report other waking symptoms. Females were significantly more likely to wake with a headache than males (OR 2.5, 95% CI 1.6 to 4.0), while all subjects aged over 60 years were significantly less likely to wake with a headache than subjects in other age groups (OR 0.6, 95% CI 0.4 to 1.0). Females exhibited a decline in waking cervical pain, stiffness and headache with increasing age. In contrast, males exhibited a peak prevalence of waking cervical pain, stiffness and headache in the 40 to 59 year age group. The prevalence of waking with aching between the scapulae or in the arm behaved differently from the other symptom groups in both genders.

Adult↗
PubMed2000

Scapular kinematics: effects of altering the Euler angle sequence of rotations.

An analysis of Euler angle sequences is presented for the scapula. In vivo kinematics were collected with a magnetic tracking device on eight healthy volunteers. To ensure accurate representation of scapular motion, pins were rigidly drilled into the scapular spine. Three rotations of the scapula with respect to the thorax were recorded during humeral elevation in the scapular plane: posterior (or backward) tilting, upward (or lateral) rotation and external rotation (or retraction). Rotations using all six possible Euler angle sequences were calculated for which each angle was represented only once. The sequence proposed by an International Society of Biomechanics subcommittee on shoulder motion (external rotation, upward rotation, posterior tilting) is consistent with both research- and clinical-based two-dimensional representations of scapular motion. Results from the present study indicate that changing sequence results in significant alterations in the description of motion, with differences up to 50 degrees noted for some angles. Therefore, in order to compare results across different laboratories, it is recommended that the proposed standard sequence be adopted.

Adult↗
PubMed2002

In vitro biomechanical analysis of glenoïds before and after implantation of prosthetic components.

Biomechanical investigations are yet necessary to better understand the origin of the glenoïd loosening which is the main reason for revision surgery. The aim of this study was to analyse the behaviour of cadaveric glenoïds before and after implantation of glenoïd prostheses. For that, we developed a new experimental protocol allowing measurement of bone strains and implants displacements under various loading cases. Ten pairs of fresh cadaveric scapulae were tested. Two kinds of loads were applied on the intact glenoïd: physiological loads corresponding to a 0-180 degrees abduction and anteflexion movements, and 500N loads. The glenoïds were then implanted with a keeled or pegged cemented polyethylene implant. The same previous 500N loads were then applied on the implanted glenoïds. Strains were measured using six strain gages placed on precise points around the peripheral cortex of the glenoïd. Displacements of implants under loading were measured using two CCD cameras. Maximum strains were obtained between 60 degrees and 120 degrees of abduction or anteflexion. They were located at the anterior and antero-superior parts of the glenoïd during abduction and at the posterior and postero-superior parts during anteflexion. Implantation of a prosthetic component generally seemed to increase strains, but tensile strains were decreased at the postero-inferior part with the antero-inferior loading point.Some differences were observed between the implants, but they have to be confirmed by further experiments. The great number of data obtained for intact scapulae could be used for a better understanding of glenoïd behaviour and for validation of finite element models.

Aged↗
PubMed1999

On the kinematic modelling and the parameter estimation of the human shoulder.

This paper presents some results on the modelling and the corresponding parameter estimation of the human shoulder. This system consists of the clavicle, the scapula, the humerus and the various joints between these bodies and the trunk through the sternum; it will be represented as a succession of a rotational joint between the sternum and the clavicle and a constant distance joint, representing the scapula between, the clavicle and the humerus head. The parameters of this system are the components of the position vectors of the joint characteristic points (the corresponding centres of the rotations). Experimental results are presented as well as a validation of the proposed model.

Acromioclavicular Joint↗
PubMed1996

Nutritional myodegeneration associated with dorsal scapular displacement in beef heifers.

Scapular displacement due to bilateral rupture of the serratus ventralis muscles ("flying scapula") occurred in four heifers from a large beef herd. Two of the four affected animals were necropsied. Additional animals on the farm developed intermittent lameness when enclosed on certain pastures. The lameness and scapular displacement were attributed to selenium deficiency in the feed and pasture environment. This is the first account of "flying scapula" in the United States.

Animals↗
PubMed1998

Relationship of the long thoracic nerve to the scapular tip: an aid to prevention of proximal nerve injury.

OBJECTIVE: The objective was to determine the course of the long thoracic nerve relative to the scapula as an aid to the prevention of proximal long thoracic nerve injuries. METHODS: Eighteen fresh cadavers (7 male, 11 female) were studied. Each was sequentially placed in the transaxillary and posterolateral thoracotomy positions, and the distance of the long thoracic nerve from the scapular tip and anterior scapular border was measured. The measurements were made bilaterally; the mean, standard deviation, and 99% confidence interval were calculated for each position by gender. RESULTS: Distances from the scapular tip to the long thoracic nerve are listed as mean/outer range: transaxillary thoracotomy, male 4.9/7.0 cm left, 5.2/7.5 cm right; female 4.3/5.0 cm left, 4.7/6.0 cm right; posterolateral thoracotomy, male 3.1/6.0 cm left, 4.5/5.1 cm right; female 3.2/4.5 cm left, 3.8/5.5 cm right. In all instances, the long thoracic nerve was furthest from the scapula at its tip. CONCLUSION: For patients positioned for a transaxillary thoracotomy, incision sites should be at least 7.5 and 6.0 cm anterior to the scapular tip for male and female patients, respectively. For patients in posterolateral thoracotomy positioning, incisions should be 6.0 and 5.5 cm anterior to the scapular tip for male and female patients, respectively. By using these anatomic guidelines, we believe that the incidence of iatrogenic proximal long thoracic nerve injury can be minimized.

Adult↗
PubMedDate not supplied

A finite element model of the shoulder: application to the comparison of normal and osteoarthritic joints.

OBJECTIVE: The objective of the present study was to develop a numerical model of the shoulder able to quantify the influence of the shape of the humeral head on the stress distribution in the scapula. The subsequent objective was to apply the model to the comparison of the biomechanics of a normal shoulder (free of pathologies) and an osteoarthritic shoulder presenting primary degenerative disease that changes its bone shape. DESIGN: Since the stability of the glenohumeral joint is mainly provided by soft tissues, the model includes the major rotator cuff muscles in addition to the bones. BACKGROUND: No existing numerical model of the shoulder is able to determine the modification of the stress distribution in the scapula due to a change of the shape of the humeral head or to a modification of the glenoid contact shape and orientation. METHODS: The finite element method was used. The model includes the three-dimensional computed tomography-reconstructed bone geometry and three-dimensional rotator cuff muscles. Large sliding contacts between the reconstructed muscles and the bone surfaces, which provide the joint stability, were considered. A non-homogenous constitutive law was used for the bone as well as non-linear hyperelastic laws for the muscles and for the cartilage. Muscles were considered as passive structures. Internal and external rotations of the shoulders were achieved by a displacement of the muscle active during the specific rotation (subscapularis for internal and infrapinatus for external rotation). RESULTS: The numerical model proposed is able to describe the biomechanics of the shoulder during rotations. The comparison of normal vs. osteoarthritic joints showed a posterior subluxation of the humeral head during external rotation for the osteoarthritic shoulder but no subluxation for the normal shoulder. This leads to important von Mises stress in the posterior part of the glenoid region of the pathologic shoulder while the stress distribution in the normal shoulder is fairly homogeneous. CONCLUSION: This study shows that the posterior subluxation observed in clinical situations for osteoarthritic shoulders may also be cause by the altered geometry of the pathological shoulder and not only by a rigidification of the subscapularis muscle as often postulated. This result is only possible with a model including the soft tissues provided stability of the shoulder. RELEVANCE: One possible cause of the glenoid loosening is the eccentric loading of the glenoid component due to the translation of the humeral head. The proposed model would be a useful tool for designing new shapes for a humeral head prosthesis that optimizes the glenoid loading, the bone stress around the implant, and the bone/implant micromotions in a way that limits the risks of loosening.

Computer Simulation↗
PubMed1985

Shoulder arthroscopy: a modified approach.

This paper proposes a modification of the classical position for shoulder arthroscopy. Two changes are proposed to improve visualization, accentuate pathology, and give better access to the inferior one half to one third of the shoulder joint. The direct lateral position is changed to a semilateral position in which the patient is allowed to rotate 30 to 40 degrees posteriorly, thus putting the shoulder joint on a horizontal plane. This allows for more comfortable arthroscopy and instrumentation. Also, if capsulorrhaphy is desired, better penetration of the scapula is possible since the scapula is vertical; thus, the angle of the approaching staple is less severe. The second change is to apply traction in a plane perpendicular to the long axis of the humerus rather than parallel to it. This modification elevates the humerus out of the glenoid rather than distracts the humerus into a subluxed position. The result accentuates labral pathology and gives a significantly improved view of the inferior one half to one third of the glenoid capsule. This new plane of traction allows excellent visualization with very little traction; thus, the problem of traction neuropraxia has been eliminated.

Adolescent↗
PubMedDate not supplied

Subscapular elastofibroma: a reactive pseudotumor.

Six cases of elastofibroma located in the subscapular region are reported. The age of the patients ranged from 45 to 71 years (mean 59.5 years). In three cases the symptoms were posterior shoulder pain with arm motion, and one of these also had a snapping scapula. Two cases had tumor prominence as the only symptom, and in one case the tumor was found accidentally while thoracotomy was being performed. On magnetic resonance imaging a nonencapsulated soft-tissue mass closely related to the thoracic wall and elevating the scapula was identified. At surgery the tumor was densely adherent to the periosteum of the ribs and the external fascia of the rib cage, and peripherally it proceeded into the loose connective tissue of the subscapular space. Local excision was performed. At follow-up 1 to 8 years after surgery no recurrence was observed, and all patients with painful lesions had complete relief of pain.

Aged↗
PubMed2002

On the development of the shoulder girdle in Crocidura russula (Soricidae) and other placental mammals: evolutionary and functional aspects.

The development of the shoulder girdle was studied in embryonic stages and a neonate of Crocidura russula using histological sections and 3-D reconstructions. Neonatal stages of Suncus etruscus and Mesocricetus auratus, both altricial placentals, were also studied. The earliest stage of C russula, in which the scapula is still partially blastematous, has already a supraspinous fossa. The dorsal portion of the scapular spine does not develop from the anterior margin of the scapula. Its mode of development varies among the placentals studied to date. In some it is completely appositional bone, in others it consists of bone formed mostly by endochondral ossification of a dorsal cartilaginous process stemming from the acromium. During development the supraspinatus muscle increases in size in proportion to the infraspinatus muscle and the humeral head increases in size in relation to the glenoid fossa. Placentals have secondary cartilage in the sternal and acromial ends of the clavicle, a derived feature absent in Marsupialia. Even the most altricial placentals have a more developed shoulder girdle at birth than any newborn marsupial studied to date.

Animals↗
PubMed2003

Failure of the biceps superior labral complex: a cadaveric biomechanical investigation comparing the late cocking and early deceleration positions of throwing.

PURPOSE: The goal of the study was to determine which position of the throwing motion, late-cocking or early deceleration, was more likely to produce lesions of the biceps superior labral complex. TYPE OF STUDY: Cadaveric biomechanical model. METHODS: Ten paired cadaver shoulders were prepared and mounted on a custom testing apparatus in 60 degrees glenohumeral abduction with the humerus in the plane of the scapula. All specimens were loaded with 100 cycles of subfailure external rotation torque (7.9 N-m) with 22 N applied to the rotator cuff tendons and long head of the biceps tendon. One of each pair of specimens was randomly tested in a late cocking position for throwing (>125 degrees external rotation, 60 degrees glenohumeral abduction, in the plane of the scapula). The other was tested in a position of early deceleration (80 degrees external rotation, 60 degrees glenohumeral abduction, 16 degrees horizontal adduction). The biceps was loaded to failure with the shoulder fixed in these positions. The specimens were then examined by 2 experienced shoulder surgeons, blinded to the test protocol, to assess for the presence of a type II SLAP lesion. RESULTS: Failure of the biceps superior labral complex occurred at the superior glenoid in 9 of 10 specimens in the late cocking position and in 2 of 10 specimens in the early deceleration position (P =.055). Five specimens developed type II SLAP lesions, with more in the late cocking position (4 of 10) than in the early deceleration position (1 of 10; P =.12). Load to failure was significantly less for the late cocking position (289 +/- 39 N) than for the early deceleration position (346 +/- 40 N; P =.004). CONCLUSIONS: These results suggest that the late cocking position may contribute to biceps-superolabral complex injuries in the thrower's shoulder.

Adult↗
PubMed1996

Neurogenic lesions after posterolateral thoracotomy in young children.

In follow-up examinations of young patients we often noticed upward displacement of the left shoulder in cases where left-sided posterolateral thoracotomy had been carried out. Finding little discussion of this side-effect in the literature, we undertook the present study. The shoulder girdle of 69 patients who had undergone surgery for coarctation of the aorta between 1964 and 1984 was carefully examined to assess displacements and dysfunctions. In addition, in 24 of the patients electrodiagnostic examination was carried out of the associated muscles and nerves which were affected by the operation. We found disturbances of the muscular apparatus of the shoulder girdle in 80% of the cases: upward displacement of the shoulder (55%), downward displacement of the shoulder (8.7%), deviation of the scapula at rest (72.5%) and maximal elevated arms (40.6%), scapula alata (56.5%), and alterations of the posterior axillary line (39.1%). When considering only the cases of distinct upward or downward displacement of the shoulder, at least 25% of the operated children were affected. Children operated early (surgery during the first year of life) had more distinct alterations (47.6%) than those with later surgery (14.6%). Electromyographic examinations indicate that mainly disorders of the peripheral nerves caused by the operation led to these alterations of the shoulder girdle musculature. Although, except for one patient, no functional disorders were found, there were several cases in which the alteration caused quite severe cosmetic problems. One should pay more attention to positioning for surgery and do careful preparation to reduce these sequelae.

Age Factors↗
PubMedDate not supplied

Direct 3-dimensional measurement of scapular kinematics during dynamic movements in vivo.

The purpose of this study was to describe 3-dimensional scapular motion patterns during dynamic shoulder movements with the use of a direct technique. Direct measurement of active scapular motion was accomplished by insertion of 2 1.6-mm bone pins into the spine of the scapula in 8 healthy volunteers (5 men, 3 women). A small, 3-dimensional motion sensor was rigidly fixed to the scapular pins. Sensors were also attached to the thoracic spine (T3) with tape and to the humerus with a specially designed cuff. During active scapular plane elevation, the scapula upwardly rotated (mean [SD] = 50 degrees [4.8 degrees ]), tilted posteriorly around a medial-lateral axis (30 degrees [13.0 degrees ]), and externally rotated around a vertical axis (24 degrees [12.8 degrees ]). Lowering of the arm resulted in a reversal of these motions in a slightly different pattern. The mean ratio of glenohumeral to scapulothoracic motion was 1.7:1. Normal scapular motion consists of substantial rotations around 3 axes, not simply upward rotation. Understanding normal scapular motion may assist in the identification of abnormal motion associated with various shoulder disorders.

Adult↗
PubMed1990

Relationship between performance of selected scapular muscles and scapular abduction in standing subjects.

The purpose of this study was to examine the relationship between muscular forces generated by the middle trapezius and pectoralis minor muscles and the position of the scapula in relaxed standing. The muscular forces of 60 subjects were measured in standard manual muscle testing positions with a hand-held dynamometer. Scapular abduction in standing was measured with a tape measure. Each measurement was taken twice, and the measurements were shown to be reliable. The correlation between scapular abduction and middle trapezius muscle force was .20. The correlation between scapular abduction and pectoralis minor muscle force was .14. The correlation between scapular abduction and a ratio of middle trapezius muscle force to pectoralis minor muscle force was .01. The results indicate that no relationship exists between the position of the scapula in standing subjects and the muscular force produced by the middle trapezius and pectoralis minor muscles. Clinical practices based on an assumed relationship between these variables (eg, the practice of using middle trapezius muscle strengthening exercises to correct a forward shoulder position) should be reexamined in light of these findings.

Adult↗
PubMed2000

Surgical management of Sprengel's deformity in adults. A report of two cases.

Sprengel's deformity is a congenital structural abnormality of the shoulder girdle, and most patients with Sprengel's deformity receive surgical treatment as a child or adolescent. Thus, it is uncommon to identify an adult with untreated Sprengel's deformity. Two adult patients who had no previous surgical treatment were treated with resection of an omovertebral bone and resection of the superomedial border of the scapula. This procedure was not overly invasive or technically demanding. In both patients resection of the omovertebral bone provided an improved cosmetic appearance and reduction in neck pain, although shoulder motion was improved in only one patient. Because the patient with a long omovertebral bone adjacent to the levator scapulae muscle showed great improvement in her shoulder motion, the size, shape, and position of the omovertebral bone may predict improvement of shoulder motion after resection. Thus, the surgical treatment of adults patients with Sprengel's deformity can produce good surgical results.

Adult↗