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Biomedical subjects

A Burstein

Publications and source records attributed to A Burstein.

45 records · Page 3Linked to original sources
PubMed1982

The influence of an experimental immune synovitis on the failure mode and strength of the rabbit anterior cruciate ligament.

The strength and failure mode of a fresh femur-anterior cruciate ligament-tibia complex was studied in normal rabbits and after the induction of an experimental immune synovitis. Five modes of failure were observed: (1) through the anterior cruciate ligament alone; (2) through a small piece of bone with the anterior cruciate ligament attached; (3) through a condyle; (4) through the metaphysis; and (5) through the diaphysis. In the normal complex, failure always occurred through the anterior cruciate ligament. In the controls, the average ratio of failure-load to body weight was seventy-four newtons per kilogram. After induction of an immune synovitis this ratio was significantly reduced, to twenty-two newtons per kilogram. Synovial cathepsin-D enzyme activity in these knees was 5.27 micromoles per hour per milligram of protein, which was significantly elevated when compared with the control level of 0.26. Histological examination of the anterior cruciate ligament after induction of the immune synovitis but before strength-testing demonstrated loss of the normal undulating fiber orientation, disorganization of the normal cellular pattern, and a decrease in the staining of the interstitial matrix with Mallory trichrome. There was a moderate infiltration of mononuclear and polymorphonuclear inflammatory cells in the body of the ligament. Histological studies of the ligament after strength-testing showed that the failure resulted in a mop-like appearance and morphological characteristics similar to those observed before testing.

Animals↗
PubMed1981

Knowles pinning of experimental femoral neck fractures: biomechanical study.

This experimental study demonstrates the rigidity and durability of Knowles pin fixation of femoral neck fractures. Embalmed proximal femora were utilized. A "fracture' was created by osteotomy, then reduced and fixed with Knowles pins. Four groups of reduction and pin configurations were created ("optimal reduction and pinning,' "poor reduction,' "inadequate pinning,' and "comminution') to simulate the clinical situation. With the Materials Testing Systems(MTS) machine, 3 months of walking by a patient with a femoral neck fracture were simulated. Results suggest that Knowles pinning of a femoral neck fracture can provide adequate support for immediate full weight-bearing ambulation until fracture healing. Stability and durability of fixation are compromised by loss of cortical bone support by "comminution,' short nonparallel pins not engaging the subchondral bone, and osteoporosis evidenced by a low Singh index.

Biomechanical Phenomena↗
PubMed1979

The National Football Head and Neck Injury Registry. Report and conclusions 1978.

The National Football Head and Neck Injury Registry has documented 1,129 injuries since 1971 that involved hospitalization for more than 72 hours, surgical intervention, fracture-dislocation, permanent paralysis, or death. Of this group of injuries, 550 were fracture-dislocations of the cervical spine, of which 176 were associated with permanent quadriplegia. It appears that during the last two decades, there has been a decrease in the incidence of direct fatalities, head injuries associated with intracranial hemorrhage, and injuries associated with death. Conversely, cervical spine injuries with fracture-dislocation and with permanent quadriplegia have increased. We believe that these observations are the result of the development of a protective helmet-face mask system that has effectively protected the head, and by so doing has allowed it to be used as a battering ram in tackling and blocking techniques, thus placing the cervical spine at risk of injury.

Athletic Injuries↗
PubMedDate not supplied

National football head and neck injury registry: report on cervical quadriplegia, 1971 to 1975.

Data on cervical spine injuries resulting from participation in football have been compiled by a national registry established in 1975. Information has been collected retrospectively by defined criteria since 1971. Efforts have been made to establish the mechanism of injury responsible in the majority of instances on the basis of epidemiologic evidence and recognized biomechanical principles. During the 5-year period, 77 deaths resulted from severe neck injuries. During this period, 1,275,000 players were exposed. Ninety-nine cervical fracture-dislocations resulting in permanent quadriplegia and 259 cervical fractures-dislocations occurred. There may be a "trend" towards an increase in permanent quadriplegia resulting from serious cervical spine injuries sustained while playing football. Apparently, the cause can be attributed to the helmet-face mask that has encouraged the use of the head as the primary point of contact in blocking, tackling, and head butting. The figures clearly identify defensive backs, linebackers, or specialty team members making tackles by using the head as the initial point of contact, as the individuals at greatest risk to sustain cervical spine injuries resulting in permanent quadriplegia.

Athletic Injuries↗