The accuracy of estimating proximal tibial translation during natural cadence walking: bone vs. skin mounted targets.

Objective: To assess the efficacy of estimating proximal tibial translation using video-based motion capture and an array of surface-mounted targets ideal for tracking motion of the tibia.

Design: Superficial and bone-anchored tracking targets were used to create two independent sets of data locating the proximal tibia in a global coordinate system.

Background: Knowledge of the effect that soft tissue movement has on estimates of proximal tibial translation has not been reported to date.

Knee moment profiles during walking: errors due to soft tissue movement of the shank and the influence of the reference coordinate system.

The effect soft tissue movement of the shank had on knee joint moments during natural cadence walking was investigated in this study. This was examined by comparing knee moments determined from bone-anchored and surface mounted tracking targets. Six healthy adult subjects participated in this study.

Objective evaluation of knee laxity in children.

This study was designed to measure objectively knee laxity in children. Physical examination and the KT 1000 arthrometer were used to test the knee laxity of 150 healthy, uninjured children between 6 and 18 years of age. Data from the knee examinations and the KT 1000 measurements were compared and statistically analyzed to determine the change in knee laxity with age, laxity differences between boys and girls, and the correlation between the KT1000 measurements and subjective tests for laxity described by Carter and Wilkinson.

Comparison of surface mounted markers and attachment methods in estimating tibial rotations during walking: an in vivo study.

The overall goal of this work was to determine an optimal surface-tracking marker set for tracking motion of the tibia during natural cadence walking. Eleven different marker sets were evaluated. The marker sets differed in the location they were attached to the shank, the method used to attach the marker sets to the segment and the physical characteristics of the marker sets.

The relationship of developmental narrowing of the cervical spinal canal to reversible and irreversible injury of the cervical spinal cord in football players.

An evaluation of forty-five athletes who had had an episode of transient neurapraxia of the cervical spinal cord revealed a consistent finding of developmental narrowing of the cervical spinal canal. The purpose of the present epidemiological study was to determine the relationship, if any, between a developmentally narrowed cervical canal and reversible and irreversible injury of the cervical cord with use of various cohorts of football players as well as a large control group. Cohort I comprised college football players who were asymptomatic and had no known history of transient neurapraxia of the cervical cord.

Nonoperative treatment of acute anterior cruciate ligament injuries in a selected group of patients.

Conservative treatment of acute anterior cruciate ligament injuries was recommended to selected patients, including those with sedentary occupations, low athletic demands, or ages greater than 30 years. Patients with generalized hyperligamentous laxity were excluded. Fifty-five of 61 patients were available at an average followup of 46 months from the time of initial injury.

Arthroscopically assisted reconstruction of the anterior cruciate ligament with use of autogenous patellar-ligament grafts. Results after twenty-four to forty-two months.

The results of the first sixty-nine consecutive patients who had had seventy arthroscopically assisted reconstructions of the anterior cruciate ligament with use of an autogenous patellar-ligament graft at our institution were reviewed retrospectively. Sixty-seven patients (sixty-eight knees) were available for evaluation after a minimum of two years. All patients had been managed with early, postoperative range-of-motion exercises and a standardized program of physical therapy.

The glenoid-labral socket. A constrained articular surface.

An anatomic study was designed to test the hypothesis that the articular surface of the glenoid fossa and labrum produces a composite socket of significant depth. Measurements were obtained from 25 anatomic specimen shoulders. The glenoid articular surface and labrum combine to create a socket that is approximately 9 mm deep in the superoinferior (SI) direction and 5 mm deep in the anteroposterior (AP) direction.

Normal and abnormal mechanics of the glenohumeral joint in the horizontal plane.

This study was performed to evaluate the relationship of the humeral head to the scapula in the horizontal plane of motion and to describe in detail a method of obtaining and interpreting modified axillary roentgenograms. Twenty normal subjects and twelve patients who had anterior instability of the shoulder were evaluated with this technique. In the control group, the humeral head was centered in the glenoid cavity throughout the horizontal plane of motion except when the arm was in maximum extension and external rotation.

Dislocation of the posterior stabilized total knee arthroplasty. A report of two cases.

This brief report details the previously unreported complication of dislocation of the posterior stabilized total knee arthroplasty. Both patients had valgus deformities requiring extensive release of the contracted lateral soft tissues. The mechanism of dislocation was one of slight flexion and external rotation.

A new model of concussive brain injury in the cat produced by extradural fluid volume loading: II. Physiological and neuropathological observations.

This study examined physiological and histopathological changes in the cat produced by a new experimental fluid injury device. Spontaneously breathing (N = 14) and artificially ventilated (N = 45) cats were subjected to systemically varied magnitudes of fluid percussion brain injury. Within certain injury ranges, increasing magnitudes of fluid percussion injury produced increasing durations of apnea, as well as greater transient increases in mean arterial blood pressure, intracranial pressure and cerebral perfusion pressure.

A new model of concussive brain injury in the cat produced by extradural fluid volume loading: I. Biomechanical properties.

This study presents a new device for producing experimental, concussive head injury together with a detailed description of biomechanical features of fluid percussion brain injury in the cat. Anaesthetized cats were subjected to multiple (N = 3) or single injuries (N = 87). The variables studied in repeated injury experiments included the volume of fluid injected intracranially, rate of fluid flow, and the associated pressure transients recorded extracranially in the injury device and intracranially at supratentorial and infratentorial sites.

Effects of naloxone on systemic and cerebral responses to experimental concussive brain injury in cats.

This study examined the effects of bolus injections of naloxone hydrochloride, a specific narcotic antagonist, on systemic cardiovascular function, intracranial and cerebral perfusion pressures, blood gas status, and cortical encephalograms (EEG's) in 38 cats after two different grades of experimental brain injury. Naloxone had no prolonged effects on uninjured control animals. However, as compared to a saline-injected control group, naloxone significantly reversed the hypotension and reduction in pulse pressure seen after higher grades of injury.