Search PubMed⌕ Search

Biomedical subjects

W W Brien

Publications and source records attributed to W W Brien.

30 records · Page 2Linked to original sources

A biomechanical evaluation of a cannulated compressive screw for use in fractures of the scaphoid.

The compressive force generated by a 3.5 mm ASIF cannulated cancellous screw with a 5 mm head was compared with that generated by a standard 3.5 mm ASIF screw (6 mm head), a 2.7 mm ASIF screw (5 mm head), and a Herbert screw. The screws were evaluated in the laboratory with the use of a custom-designed load washer (transducer) to the maximum compressive force generated by each screw until failure, either by thread stripping or by head migration into the specimen. Testing was done on paired cadaver scaphoids. To minimize the variability that occurs with human bone, and because of the cost and difficulty of obtaining human tissue specimens, a study was also done on polyurethane foam simulated bones. The 3.5 cannulated screw generated greater compressive forces than the Herbert screw but less compression than the 2.7 mm and 3.5 mm ASIF cortical screws. The 3.5 mm cannulated screw offers more rigid internal fixation for scaphoid fractures than the Herbert screw and gives the added advantage of placement over a guide wire.

Biomechanical Phenomena↗

Subtrochanteric femur fractures: a comparison of the Zickel nail, 95 degrees blade plate, and interlocking nail.

Seventy-nine nonconsecutive patients with subtrochanteric femur fractures were divided into three groups based on the method of fracture fixation. Group I consisted of 21 patients treated with a Zickel nail, Group II comprised 25 patients treated with a 95 degrees blade plate, and Group III included 33 patients treated with an interlocking nail. All patients in Group I and Group II had open reduction and internal fixation of their fractures. Ninety-four percent of the patients in Group III were treated by closed intramedullary nailing. The average operating times for Groups I, II, and III were 212, 272, and 181 min, respectively, while blood loss averaged 900, 1,500, and 600 ml for each group, respectively. Group I had one infection, ten malunions, and one nonunion. Group II had one infection, six malunions, and two nonunions. Group III had no infections, two malunions, and one nonunion. We conclude that closed interlocking nailing is the treatment of choice for acute nonpathologic subtrochanteric femur fractures in adults. There is decreased blood loss, reduced operating time, and fewer complications than with either the Zickel nail or the 95 degrees blade plate regardless of the fracture pattern or the degree of fracture comminution.

Adult↗

Interlocking nailing for the treatment of femoral fractures due to gunshot wounds.

Fifty-six patients who had a fracture of the femur due to a low-velocity gunshot injury were treated with interlocking nailing with the Grosse-Kempf nail. Patients who had an isolated fracture were treated by intravenous administration of antibiotics followed by delayed interlocking nailing. Ninety-three per cent of the fractures had Grade-III or IV comminution. At an average duration of follow-up of sixteen months (range, twelve to twenty-nine months), the results of closed interlocking nailing were excellent. All of the fractures united an average of twenty-three weeks (range, fourteen to forty weeks) after the nailing. There were no apparent infections in the entire series. There were two delayed unions and seven malunions. Five patients had a serious associated vascular injury; four of these five had interlocking nailing immediately after vascular repair. The fractures united without any residual vascular insufficiency.

Adult↗

Complications associated with carpal tunnel release.

A number of complications can result from surgical treatment of carpal tunnel syndrome. They can be diminished with the use of a longitudinally directed incision, complete visualization of the median nerve, and an understanding of the anatomic variations of the median nerve. However, some complications (eg, a painful scar, infection, and wrist weakness) may not be completely prevented.

Carpal Tunnel Syndrome↗

Gunshot injuries to the hip and abdomen: the association of joint and intra-abdominal visceral injuries.

A retrospective review of all gunshot injuries to the hip at our medical center over a 24-year period was performed. Adequate information and radiographs were available for 49 patients. Of these, five patients (10.2%) had associated abdominal visceral injuries. These five patients were examined at an average of 5.9 years after their injury, and compared by utilizing the Harris Hip Score rating. Radiographs were also obtained. Four of these five patients (80%) had initially developed infections in their hip joints, with all four having poor functional outcomes, with an average Harris Hip Score of 48.5 from their hip injury. Careful initial evaluation and aggressive surgical and antibiotic treatment are recommended to prevent these poor results.

Abdominal Injuries↗

Acetabular reconstruction with a bipolar prosthesis and morseled bone grafts.

The results of eighteen acetabular reconstructions in which a bipolar prosthesis and morseled bone grafts were used for a major acetabular defect were evaluated. Thirteen Type-II (cavitary) and five Type-III (combined) acetabular deficits were treated. All of the patients were followed for at least two years. The procedure failed in eleven patients: six had radiographic evidence of complete resorption of the bone grafts and migration of the acetabular component; three, deep infection; one, recurrent dislocation; and one, pain of undetermined cause despite a satisfactory radiographic appearance of the hip. The remaining seven patients had a satisfactory clinical outcome. However, an improved acetabular bone structure, as judged by radiographic evidence of incorporation of the bone grafts, was maintained in only four patients. In our experience, acetabular reconstruction with morseled bone grafts and a bipolar prosthesis was associated with a high rate of failure, and we do not recommend that it be performed routinely. It should be considered only as a salvage procedure in elderly or infirm patients, as a possible alternative to more extensive procedures.

Acetabulum↗

The effect of intravenous fixed-dose heparin during total hip arthroplasty on the incidence of deep-vein thrombosis. A randomized, double-blind trial in patients operated on with epidural anesthesia and controlled hypotension.

Heparin was given in fixed doses intravenously during unilateral primary total hip-replacement operations in a prospective, double-blind trial to assess the effect on the incidence of deep-vein thrombosis. One hundred and fifty patients were randomly assigned to one of two groups before the operation. Twenty-four patients were excluded from the study, leaving 126 patients. Group I consisted of sixty-six patients who received saline solution intravenously, and Group II comprised sixty patients who received heparin. All patients had epidural anesthesia with controlled hypotension. Fixed doses of heparin were administered five minutes before the operative incision was made and every thirty minutes throughout the operation. Mean arterial pressures were maintained at between fifty and sixty millimeters of mercury in all patients. Ascending venography was done on the seventh day after the operation. The incidence of deep-vein thrombosis was 24 per cent (sixteen of sixty-six patients) in Group I and 8 per cent (five of sixty patients) in Group II; the difference is significant (p = 0.03). The intraoperative loss of blood averaged 220 +/- 79 milliliters in Group I compared with 269 +/- 109 milliliters in Group II. An average of less than one unit of blood was transfused for each patient in each group. Postoperatively, there was no difference between the groups with regard to the amount of drainage that was collected in a Hemovac device or the values for hematocrit.

Female↗

Interlocked nailing for treatment of segmental fractures of the femur.

Thirty-three segmental fractures of the shaft of the femur were treated with the Grosse-Kempf interlocking nail. Twenty-eight of the fractures had been caused by high-energy trauma. There were twenty-six closed and seven open fractures. Thirty-two of the thirty-three fractures united, at an average of thirty-two weeks, without additional intervention other than dynamization of the nail. There were one non-union, one delayed union, and two malunions. Virtually all fractures located between the lesser trochanter and the femoral condyles can be nailed, regardless of the pattern of the fracture or the degree of comminution. Closed interlocked nailing is the treatment of choice for most segmental fractures of the shaft of the femur.

Adolescent↗

Management of fractures of the humerus in patients who have an injury of the ipsilateral brachial plexus.

Twenty-one adults who had a fracture of the middle of the humeral shaft and an injury of the ipsilateral brachial plexus were followed for an average of twenty-eight months. Only two of these patients showed evidence of neurological improvement. Of the eleven patients who had an associated traumatic injury to the brain, eight were treated non-operatively and three, operatively. The presence of a fracture of the humerus in a flail extremity has been found to delay rehabilitation markedly and to result in prolonged hospitalization. Eleven fractures were treated non-operatively with a brace or cast, and there were five non-unions, two delayed unions, and two malunions. Of the ten fractures that were treated operatively, three that were treated by compression-plating all united. Two fractures were treated by external fixation; one had a delayed union and one, a malunion. In the remaining five patients, who were treated with an intramedullary rod, there were two non-unions, one delayed union, and one malunion.

Adolescent↗

Wound site as a predictor of complications following deep nail punctures to the foot.

The site of injury, condition of the nail, and type of foot covering were compared in 36 inpatients and 34 outpatients with nail puncture wounds to the foot. Of the 36 inpatients, 34 (94%) had pyarthrosis, osteomyelitis, or both. The plantar surface of the foot was divided into 3 zones. Of the 36 inpatients, 35 (97%) had deep puncture wounds in zone 1. In contrast, only 6 of 34 (18%) outpatients had injury to this area. Tennis shoes were shown to predispose to infection with Pseudomonas aeruginosa. Based on our findings, an early hospital admission should be considered for all patients with deep puncture wounds located in zone 1 and for patients who give a history of bone penetration in zone 2 or 3 at the time of injury. All patients who meet the above criteria and who are not admitted to hospital should be observed closely.

Adolescent↗