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Biomedical subjects

R F Ostrum

Publications and source records attributed to R F Ostrum.

At least 19 recordsLinked to original sources
PubMed2000

Treatment of floating knee injuries through a single percutaneous approach.

The current study is a review of 20 patients treated by percutaneous stabilization for a floating knee. All patients were treated with a retrograde femoral intramedullary nail and a small diameter tibial intramedullary nail through a 4-cm medial parapatellar tendon incision. The average Injury Severity Score was 19. Two patients died in the early postoperative period and one patient was lost to followup. The average time to union for the 17 remaining patients with femoral shaft fractures was 14.7 weeks. One patient required dynamization. Four of the 17 patients with tibia fractures required an exchange nailing procedure, one with bone graft, to achieve union. One patient required dynamization and one patient with bone loss required only a bone graft. The average time to union for the tibia fractures was 23 weeks. One patient achieved 115 degrees knee flexion and the remaining 15 patients had full knee motion by 12 weeks, which they were able to maintain. No patient had signs or symptoms of knee pain. This demanding surgical technique using a small incision has yielded good clinical results. Although it is an excellent treatment option for patients with ipsilateral femoral and tibial shaft fractures, the mortality and tibial fracture complication rates remain high.

Adolescent↗
PubMed2000

Retrograde nailing for subtrochanteric femur fractures.

This study reviews the results of subtrochanteric femur fractures treated with a retrograde nail at a level 1 trauma center. Sixteen patients with 17 fractures were followed up until union. The average Injury Severity Score (ISS) was 19, and average knee range of motion was 127 degrees. Four patients required dynamization of their nail, and three healed over a prolonged period of time. Two patients required exchange nailing: one after failure of union after dynamization and one with a broken nail that was revised to an antegrade nailing. The average varus deformity was 5.06 degrees and only 35% of fractures healed in greater than 5 degrees of varus, with an average time to union of 22.4 weeks (range, 6-54 weeks). Antegrade nailing remains the treatment of choice for the vast majority of subtrochanteric femur fractures. However, retrograde femoral nailing may be an effective treatment option for some subtrochanteric fractures in a selected group of patients.

Adolescent↗
PubMed1999

Effects of retrograde femoral intramedullary nailing on the patellofemoral articulation.

OBJECTIVE: To determine the patellofemoral contact areas as well as mean and maximal pressures after retrograde intramedullary nailing in a cadaveric model. STUDY DESIGN: Pressure-sensitive film was used to analyze patellofemoral joint pressures after insertion of a retrograde femoral nail in a cadaveric specimen. METHODS: A retrograde femoral nail was inserted into seven cadaveric knees. Pressure-sensitive film was placed into the patellofemoral joint and physiologic loads (700 newtons) were applied to the knee joint at 90 degrees and 120 degrees of flexion. Testing was performed with the nail three millimeters deep to the cartilage (In), flush with the cartilage (Flush), and one millimeter prominent (Out). The intact knee served as the Control. RESULTS: The mean contact areas showed no statistical differences among the four groups. There was a significant increase in mean pressure at 120 degrees and maximum pressure at 90 degrees and 120 degrees for the Out group when compared with the Control, In, and Flush groups (p < 0.001). CONCLUSIONS: There were no significant differences in mean contact pressure, contact area, or maximum pressure among the Control, three-millimeter insertion depth, or flush insertion groups. There was, however, a significant increase in mean and maximum pressures with the nail one millimeter prominent. These results indicate that placement of a retrograde femoral intramedullary nail is critical, but that proper placement should not significantly influence the biomechanics of the patellofemoral joint.

Biomechanical Phenomena↗
PubMed1999

Knee dislocations.

Explore the source record for details and available documents.

Anterior Cruciate Ligament Injuries↗
PubMed1998

A calcaneal fracture with extrusion of the posterior facet.

This is a case report of a 19-year-old woman who sustained multiple fractures including a right calcaneal fracture with extrusion of the posterior facet. The medial soft-tissue injury led to a full thickness skin loss. Despite loss of subtalar motion and decreased toe movement, she is satisfied with her result. The importance of the soft-tissue injuries, especially to the skin and tendons, associated with severely displaced calcaneal fracture dislocations is emphasized by this case report.

Adult↗
PubMed1996

Posterior plating of displaced Weber B fibula fractures.

This is a prospective study that examines 32 patients who were treated with posterior plating of a displaced Weber B fibula fracture and had a minimum of 1 year follow-up. The surgical technique included application of an unbent one-third tubular plate to the posterior aspect of the fibula using the antiglide technique. Twenty-seven fractures were classified as supination-eversion IV: 13 with deltoid disruption and 14 with a medial malleolar fracture. Three were classified as pronation-abduction and two as low pronation-eversion fractures at the level of the plafond. A six-hole plate was used most often (18 cases), and 23 patients had a lag screw placed through the plate. There were no nonunions or malunions. No wound complications, screw loosening, loss of fixation, intraarticular screws, or palpable screws were found. Four patients had transient peroneal tendinitis that resolved in 4-8 weeks. Two patients had later plate removal caused by poor technique because of a symptomatic lag screw. Twenty of the 21 patients who returned a questionnaire were satisfied with their result (95%). Posterior fibular plating offers many advantages over lateral plating, including the possibility of no intraarticular or palpable screws and an improved and stronger distal fixation construct. Our favorable results suggest that this technique should be given consideration as a treatment of choice for displaced Weber B fibula fractures.

Bone Plates↗
PubMed1996

A greater trochanteric insertion site for femoral intramedullary nailing in lipomatous patients.

This is a review of the treatment of 12 femoral shaft fractures and three nonunions in lipomatous patients who had a greater trochanteric insertion point for intra medullary nailing. Indications included overweight patients and trochanteric lipodystrophy. Combined with a small proximal extension of the incision, maximal limb adduction, and a slotted intramedullary nail, the greater trochanteric insertion point was effective, and no complications directly related to this procedure were encountered.

Adolescent↗
PubMed1995

Indirect reduction and internal fixation of supracondylar femur fractures without bone graft.

Thirty supracondylar-intercondylar fractures of the distal femur were treated in a prospective series using an indirect reduction technique. From January 1988 to July 1993, patients who entered into this protocol had undergone fixation with a distal lateral plate without stripping of the medial soft tissues and without bone graft. With this technique, 86.6% excellent and satisfactory results were achieved using the Neer rating system. Of the three failures, two were in elderly, osteoporotic women with comminuted intraarticular fractures, and one failure occurred in a renal transplant patient with bilateral quadriceps ruptures despite a good result from her femur fracture. Only one patient with a grade 2 open fracture and comminution developed a nonunion, which eventually healed after bone grafting. The results of this technique compare favorably with other series of osteosynthesis of supracondylar femur fractures in the orthopaedic literature without the added morbidity associated with autogenous bone grafting. The surgical technique is demanding and may not be suitable for patients with severe open fractures with devascularized bony fragments or marked osteoporosis.

Adolescent↗
PubMed1995

A critical analysis of the anterior-posterior radiographic anatomy of the ankle syndesmosis.

To determine the normal anatomic radiographic land-marks of the ankle syndesmosis, standardized anterior-posterior radiographs of the right ankle were performed on 40 male and 40 female volunteers. The average tibiofibular clear space was 3.8 mm in females, 4.6 mm in males, and 4.2 mm overall. The tibiofibular overlap measured 6.0 mm in females, 9.6 mm in males, and 7.8 mm overall. Due to this variability and the gender differences, we investigated the anatomy of the syndesmosis as ratios of the potentially variable values to fixed landmarks. The ratio of the tibiofibular overlap to the fibular width averaged 54% and the ratio of the tibiofibular clear space to the fibular width averaged 30%, with no statistically significant difference due to gender. Our data show that for 90% prediction intervals, the values are: (1) tibiofibular clear space less than 5.2 mm in women and 6.5 mm in men; (2) tibiofibular overlap of greater than 2.1 mm in females and 5.7 mm in males; (3) tibiofibular overlap:fibular width ratio greater than 24%; (4) tibiofibular clear space:fibular width ratio less than 44%. Additionally, using a linear regression model, a prediction of the tibiofibular overlap can be made when using the distance (in millimeters) from the incisura fibularis to the lateral tibial (LT) border: tibiofibular overlap = 0.862 x lateral tibia - 2.62 (P = .0001). Utilization of these values will help in the determination of posttraumatic disruption of the syndesmosis and postoperative assessment of mortise reduction.

Adolescent↗
PubMed1995

The surgical anatomy of the radial nerve around the humerus.

Twenty-four cadaveric arms were dissected to determine the position of the radial nerve on the posterior aspect of the humerus relative to the posterior tip of the acromion, the medial and lateral epicondyles, the division between the lateral and long heads of the triceps, and the triceps aponeurosis. The radial nerve passed anterior to the long head of triceps and cross onto the posterior shaft of the humerus an average of 124 mm below the posterior tip of the acromion. It was never closer than 97 mm. The nerve usually lies on the medial head of the triceps as it courses posteriorly around the humerus and then leaves the posterior shaft of the humerus an average of 126 mm above the lateral epicondyle and 131 mm above the medial epicondyle. It was never within 100 mm of either epicondyle. The surgeon can use these landmarks as guidelines to avoid the radial nerve during operative intervention on the humerus.

Aged↗
PubMed1994

Limited internal fixation of the tibia with external fixation: an in vivo canine study.

This study reports the results of the healing of canine tibial osteotomies with external fixation alone or in combination with a single lag screw. Twelve dogs had a midshaft tibial osteotomy performed at a 45 degree obliquity. Half of the dogs had a six-pin, unilateral, medial, external half-frame applied after the osteotomy. The remaining six had an identical frame plus a lag screw placed perpendicular to the osteotomy site. When compared with their contralateral controls, the fixator-alone group had a 16.3% (p < 0.05) decrease in bone density, whereas no significant density change was seen in the group with the additional lag screw. Torsional stiffness was 29% higher in the osteotomies treated, and tested, with the lag screw, but this did not achieve statistical significance. Computed tomography scanning revealed that the surface area was increased by an average of 30-40% in both groups, relative to contralateral controls, but there was no difference between the two treatment groups. Three tibias in the group with external fixation alone, and two tibias in the screw group showed primary bone healing without evidence of callus formation. The combination of a semirigid external fixation construct with a lag screw resulted in increased torsional stiffness but healing equal to that seen with external fixation alone.

Animals↗
PubMed1993

The lack of association between femoral shaft fractures and hypotensive shock.

A retrospective review of all patients with femur fractures was performed to determine whether isolated femoral shaft fractures were associated with hypotensive shock. One hundred patients were identified who had either an isolated femoral shaft fracture (group F, 62 patients) or a femoral shaft fracture in addition to other non-shock producing fractures or minor injuries (group A, 38 patients). No patients in this study were in class III or IV (hypotensive) shock; however, 11% progressed from no shock to class I and 13% from class I to class II. Logistic regression showed no association between class II shock and age, sex, or weight. The presence of additional fractures (p = 0.004) and total fluids received from fracture to stabilization (p = 0.014) had a highly significant association with class II shock in a joint analysis. Mechanism of injury, although significant as an independent variable, was highly associated with the presence of additional fractures and so is not required in the joint model. Femur fractures alone or in combination with other minor injuries should not be considered the cause of hypotensive shock in the traumatized patient. In the traumatized patient who presents with a closed femoral shaft fracture and hypotension, an alternative source of hemorrhage should be sought.

Adolescent↗
PubMed1993

Nocardia septic arthritis of the hip with associated avascular necrosis. A case report.

Nocardiosis is a rare infection seen most commonly in immunocompromised patients. Most have pulmonary involvement, but some develop disseminated infection. There are few case reports of septic arthritis attributable to hematogenous nocardiosis. In this case, a heart transplant patient was ultimately proven to have a Nocardia septic hip but represented a diagnostic challenge because of preexisting avascular necrosis. With the increasing number of allograft recipients and concomitant immunosuppression, the possibility of an increase in Nocardia opportunistic infections exists. Avascular necrosis, attributable to corticosteroid use, may predispose patients to hip joint infection.

Arthritis, Infectious↗
PubMed1992

Tension band fixation of medial malleolus fractures.

A prospective study on tension band fixation of medial malleolus fractures was performed on 30 consecutive patients with 31 fractures from October 1987 until December 1990. All patients had at least a displaced medial malleolus fracture unreduced by closed methods. The fractures were classified into small, medium and large using a modified Lauge-Hansen classification. There were no nonunions or movements of wires postoperatively and only two patients had subjective complaints with reference to the wires that required hardware removal. There was one 2-mm malreduction and one patient with a wound slough and subsequent osteomyelitis. One fragment had 2 mm of displacement after fixation but went on to union. A biomechanical study was undertaken to compare fixation of the medial malleolus with K wires alone, K wires plus a tension band, and two cancellous screws. The tension band fixation provided the greatest resistance to pronation forces: for times stiffer than the two screws and 62% of the intact specimen. Tension band fixation of the medial malleolus is a biomechanically strong and clinically acceptable method of treatment for displaced medial malleolus fractures. This method of fixation may be especially useful for small fragments and in osteoporotic bone.

Aged↗
PubMed1992

Customized plating techniques for juxta-articular fractures and osteotomies.

Juxta-articular fractures and osteotomies must be reduced and maintained in satisfactory position to allow for normal joint function at both the involved joint and the adjacent ones. Internal fixation of these fractures is often difficult because of the proximity of the fracture site to the articular cartilage. Modification of currently available bone plates by customization can increase the orthopaedist's armamentarium and allow rigid fixation with early motion. This will help attain early functional recovery and good long-term results.

Adult↗