Biomedical subjects

R D Blasier

Publications and source records attributed to R D Blasier.

25 records · Page 2Linked to original sources

PubMedDate not supplied

Serial magnetic resonance imaging of hamstring anterior cruciate ligament autografts during the first year of implantation. A preliminary study.

A prospective, observational study was performed to document the serial changes in the magnetic resonance signal of devascularized, hamstring ACL autografts during the 1st year of implantation. Twenty-one ACL deficient knees (14 chronic, 7 acute) were reconstructed. Instability developed in five knees within the first 6 months of graft implantation (24%). Magnetic resonance examinations were performed at 1, 6, 12, 24, 36, and greater than 48 weeks postoperatively (repetition time 1500, echo delay time = 50). A total of 104 scans were reviewed (average, five per knee). The ACL graft was divided into four unequal size zones for analysis. The proximal, middle, and distal thirds of the intraarticular portion of the graft and the portion of the graft within the tibial tunnel were independently analyzed. The magnetic resonance signal in each portion of the graft was graded on a scale with (I) being a normal signal, (II) greater than 50% of the total volume of the graft having a normal signal, (III) less than 50% of the graft having a normal signal, and (IV) 100% of the graft having an increased signal. The increased magnetic resonance signal of the ACL graft was observed to be regionalized and confined to the distal two-thirds of the intraarticular portion of the graft. The portion of the graft exiting the femoral tunnel and within the tibial tunnel retained a normal magnetic resonance signal. The increases in magnetic resonance graft signal were time-dependent, became well established by 3 months, and remained unchanged at 1 year. The clinical outcome could not be predicted based on the magnetic resonance signal of the graft.

Adolescent↗

PubMedDate not supplied

Simulated lateral ankle ligamentous injury. Change in ankle stability.

The effect of simulated ankle ligamentous injury on ankle-subtalar joint complex laxity was studied. Thirty-six intact ankles were loaded in inversion-eversion and anterior-posterior directions. Motions of the talus and calcaneus were measured with respect to the tibia. Ankles were tested at neutral, 15 degrees of dorsiflexion, and 15 degrees of plantar flexion. In all the specimens the anterior talofibular ligament was sectioned and then the calcaneofibular ligament was sectioned; testing was then repeated. With sectioning of the anterior talofibular ligament, motion increased primarily in dorsiflexion with both anterior-posterior and inversion-eversion loading. This increase was primarily caused by a large increase in subtalar motion. Additional sectioning of the calcaneofibular ligament produced little change in ankle subtalar joint motion except in dorsiflexion. Clinically, these findings show that if an anterior-posterior drawer test shows less laxity in dorsiflexion than in neutral and greater laxity than the contralateral asymptomatic side, then an isolated anterior talofibular ligamentous tear exists. Similarly, laxity in 15 degrees of dorsiflexion and in neutral suggests calcaneofibular ligament disruption. During inversion-eversion loading, the increase in ankle-subtalar joint complex rotation with calcaneofibular ligament sectioning occurred primarily in the ankle joint, implying that the calcaneofibular ligament constrains the talus through the calcaneus. Therefore, a talar tilt on stress radiographs demonstrates a torn calcaneofibular ligament.

Ankle Injuries↗

PubMedDate not supplied

Biomechanical comparison of reconstruction techniques in simulated lateral ankle ligament injury.

Eighteen intact ankles were loaded with inversion-eversion and anterior-posterior forces, and motions of the talus and calcaneus were measured. Ankles were tested in neutral, 15 degrees of dorsiflexion, and 15 degrees of plantar flexion. The anterior talofibular ligament was then sectioned and testing was repeated. In half the specimens the calcaneofibular ligament was also sectioned followed by repeat testing. The Evans, Watson-Jones, and Chrisman-Snook procedures were performed on each ankle and testing was repeated. With inversion-eversion loading, only the Chrisman-Snook reconstruction resulted in a significantly more stable ankle joint complex than in the anterior talofibular ligament cut ankles. All three reconstructions increased ankle stability over the anterior talofibular and calcaneofibular ligament cut state. With anterior-posterior loading, all reconstructions resulted in a significantly more stable ankle joint complex than the anterior talofibular ligament cut ankles. The Evans and Chrisman-Snook procedures resulted in more stability than the anterior talofibular and calcaneofibular ligament cut ankles. There was no difference in subtalar joint motion with inversion-eversion loading among ankles with the anterior talofibular ligament cut and those with any of the reconstructions. For the anterior talofibular and calcaneofibular ligament cut ankles, subtalar joint motion was similar to that in intact ankles after each reconstruction. All three reconstructions resulted in ankles with significantly less subtalar joint motion with anterior-posterior loading than ankles with the anterior talofibular ligament cut or with the anterior talofibular and calcaneofibular ligaments cut. The Chrisman-Snook procedure resulted in ankles with significantly less motion than intact ankles.

Analysis of Variance↗

PubMedDate not supplied

Intravenous regional anesthesia: a safe and cost-effective outpatient anesthetic for upper extremity fracture treatment in children.

We reviewed our most recent 100 consecutive cases with respect to efficacy and safety of anesthesia in which Bier block anesthesia was used to reduce upper extremity fractures. Records were reviewed to document diagnosis, number of reduction attempts, efficacy of anesthesia, and incidence of complications and untoward effects. No adverse effects were noted from lidocaine injection or tourniquet release. The cost of Bier block anesthesia administered in the emergency room (ER) was significantly less than that of a general anesthetic in the operating room. We have found the Bier block to be a safe, reliable, and cost-effective anesthetic in treatment of children's upper extremity fractures in the ER.

Adolescent↗

PubMedDate not supplied

Clubfoot: nature and treatment.

1. Clubfoot is a relatively common abnormality that occurs in 1 per 1,000 live births. Untreated, clubfoot precludes normal gait because the patient is forced to walk on the lateral side of the forefoot. 2. Treatment of clubfoot should begin at birth to avoid a fixed and disabling deformity. Early treatment routinely involves serial manipulation, followed by adhesive strapping or casting of the manipulated foot to hold the correction. Although less than half of congenital clubfoot cases treated from birth will respond to serial manipulation and casting, it is generally the first choice of treatment. 3. If serial manipulation and adhesive strapping or casting do not correct the deformity, then surgery, one small part in the ongoing treatment, is necessary. With adequate preparation and planning, maximum benefit can be obtained from the surgical experience.

Casts, Surgical↗

PubMedDate not supplied

External fixation of pediatric femur fractures.

One-hundred and thirty-two children with 139 femur fractures were treated with external fixation from 1984 to 1993. Average age at presentation was 8.97 years. All fractures were followed until union, with an average time of external fixation of 11.4 weeks. There were no nonunions. Of 18 patients with definitive radiographic measurements at 2-year follow-up, 15 patients developed overgrowth (average, 8.7 mm) and three demonstrated shortening (average, 7.7 mm). No patient required treatment for residual leg-length discrepancy. Although pin-tract inflammation was common, pin-tract infection requiring intravenous antibiotics occurred in only six patients (4.5%). No patient developed osteomyelitis. Two fractures (1.4%) were not healed at the time of elective fixator removal, necessitating additional time in the fixator. There were two refractures (1.4%) and one fracture through a healing pin tract after fixator removal (0.7%).

Adolescent↗

PubMedDate not supplied

Duration of immobilization after percutaneous sliding heel-cord lengthening.

Heel-cord lengthening is commonly performed for contractures in neuromuscular disease. Immobilization after this procedure has ranged from 3 to 8 weeks. A three-part study was performed to determine adequate length of immobilization. Sixteen rabbits had surgical transection of the right gastrocsoleus tendon in phase 1. Healing was allowed for 1, 3, 5, or 7 weeks. Tendons were then studied by magnetic resonance imaging (MRI), mechanical testing, or histologic section. A marker for healing was determined by MRI. Seven children underwent percutaneous sliding heel-cord lengthening (PSHCL) in phase 2. Healing was studied by MRI. Based on the marker from phase 1, adequate healing occurred at 3 weeks. Thirty-one children underwent PSHCL for neuromuscular contracture in phase 3. Cast immobilization was maintained for 3 weeks (group 1) and for >3 weeks (group 2). There was no evidence of rupture or progressive lengthening after cast removal in either group.

Achilles Tendon↗