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Biomedical subjects

J E Alonso

Publications and source records attributed to J E Alonso.

At least 19 recordsLinked to original sources

Deep-vein thrombosis in high-energy skeletal trauma despite thromboprophylaxis.

We report the incidence and location of deep-vein thrombosis in 312 patients who had sustained high-energy, skeletal trauma. They were investigated using magnetic resonance venography and Duplex ultrasound. Despite thromboprophylaxis, 36 (11.5%) developed venous thromboembolic disease with an incidence of 10% in those with non-pelvic trauma and 12.2% in the group with pelvic trauma. Of patients who developed deep-vein thrombosis, 13 of 27 in the pelvic group (48%) and only one of nine in the non-pelvic group (11%) had a definite pelvic deep-vein thrombosis. When compared with magnetic resonance venography, ultrasound had a false-negative rate of 77% in diagnosing pelvic deep-vein thrombosis. Its value in the pelvis was limited, although it was more accurate than magnetic resonance venography in diagnosing clots in the lower limbs. Additional screening may be needed to detect pelvic deep-vein thrombosis in patients with pelvic or acetabular fractures.

Acetabulum↗

Fracture stabilization of proximal tibial fractures with the proximal tibial LISS: early experience in Birmingham, Alabama (USA).

This study is a prospective evaluation of the Less Invasive Stabilization System (LTSS) for the treatment of high-energy tibial plateau and proximal tibial fractures treated between November, 1998 and June, 2000. Thirty-two patients sustained thirty-five acute fractures of the tibial plateau (25) or proximal tibia (10). These patients were injured primarily in blunt trauma accidents, with eighteen having multiple fractures, fifteen having ipsilateral extremity fractures, and eleven having major knee ligament injuries. Seventeen patients had open fractures. Thirty-four patients healed their fractures, with one developing a nonunion. Two patients developed infections, both following Type III open fractures. Final range of motion averaged 2 to 116 degrees. Alignment was well maintained, with no patient losing the alignment that was obtained in the operating room. The tibial LISS system worked well at stabilizing difficult fractures of the tibial plateau and proximal tibia with a low incidence of complications in this preliminary study with short-term follow-up.

Adult↗

Elastic and viscoelastic properties of the human pubic symphysis joint: effects of lateral impact joint loading.

The human pelvis is susceptible to severe injury in vehicle side impacts owing to its close proximity to the intruding door and unnatural loading through the greater trochanter. Whereas fractures of the pelvic bones are diagnosed with routine radiographs (x-rays) and computerized tomography (CT scans), non-displaced damage to the soft tissues of pubic symphysis joints may go undetected. If present, trauma-induced joint laxity may cause pelvic instability, which has been associated with pelvic pain in non-traumatic cases. In this study, mechanical properties of cadaveric pubic symphysis joints from twelve normal and eight laterally impacted pelves were compared. Axial stiffness and creep responses of these isolated symphyses were measured in tension and compression (perpendicular to the joint). Bending stiffness was determined in four primary directions followed by a tension-to-failure test. Loading rate and direction correlated significantly (p<0.05) with stiffness and tensile strength of the unimpacted joints, more so than donor age or gender. The impacted joints had significantly lower stiffness in tension (p <0.04), compression (p<0.003), and posterior bending (p<0.03), and more creep under a compressive step load (p<0.008) than the unimpacted specimens. Tensile strength was reduced following impact, however, not significantly. We concluded that the symphysis joints from the impacted pelves had greater laxity, which may correlate with post-traumatic pelvic pain in some motor vehicle crash occupants.

Accidents, Traffic↗

Mechanical prophylaxis against deep-vein thrombosis after pelvic and acetabular fractures.

BACKGROUND: Deep-vein thrombosis is a common complication following pelvic and acetabular fractures. The hypothesis of this study was that pulsatile mechanical compression is superior to standard sequential mechanical compression for decreasing the prevalence of deep-vein thrombosis in patients with pelvic or acetabular fracture. METHODS: A prospective, randomized, blinded study of two methods of mechanical prophylaxis against deep-vein thrombosis was conducted. One hundred and seven patients were randomized into either Group A (fifty-four patients), in which a thigh-calf low-pressure sequential-compression device was used, or Group B (fifty-three patients), in which a calf-foot high-pressure pulsatile-compression pump was used. All patients underwent duplex ultrasonography and magnetic resonance venography. The two groups were comparable with regard to demographics, fracture type, fracture treatment, time from the injury to the prophylaxis, and patient compliance. RESULTS: Deep-vein thrombosis developed in ten patients (19%) in Group A, with seven (13%) having a large or occlusive clot and one (2%) having a documented pulmonary embolism. Deep-vein thrombosis developed in five patients (9%) in Group B, with two (4%) having a large or occlusive clot and none having a documented pulmonary embolism. Nine of the nineteen detected thromboses were in the deep pelvic veins. The difference in the prevalence of large or occlusive clots between the two groups demonstrated a trend but, with the numbers available, was not significant (p = 0.16). Increased patient age and the time elapsed from the injury to the surgery were found to be associated with higher rates of thrombosis. CONCLUSIONS: Pulsatile compression was associated with fewer deep-vein thromboses than was standard compression, with the difference representing a trend but not reaching significance with the number of patients studied.

Acetabulum↗

A prospective evaluation of the timing of postoperative radiotherapy for preventing heterotopic ossification following traumatic acetabular fractures.

PURPOSE: Preoperative and immediate postoperative irradiation of traumatic acetabular fractures (TAF), although known to reduce heterotopic ossification (HO), can cause significant organizational and logistic difficulties. We sought to determine an acceptable time interval between surgery and radiation without compromising control, as well as to update our large experience and to further validate our treatment philosophy. METHODS AND MATERIALS: Beginning in June 1995, we began a prospective study, irradiating 152 patients on postoperative days 1, 2, or 3. There were also 17 patients delayed further secondary to medical difficulties. RESULTS: All patients treated since June 1995 received 700 cGy/1 fx. Fifty-eight patients received radiation within 24 hours of surgery, 41 within 2 days, 53 within 3 days, 13 within 4 days, and 4 were delayed further. Delaying irradiation for up to 4 days postoperatively caused no statistical increase in HO (p = 0.625). Of 263 patients in our retrospective cohort, HO occurred in 5.3% of patients who received irradiation versus 60% of patients who did not. CONCLUSION: In our prospective study, we noted no perceptible increase in HO with up to a 3-day interval between surgery and radiotherapy. This allows a more structured treatment schedule and allows the patient more time to heal and recover. Updated results from our overall series continue to demonstrate that adjuvant radiation decreases the incidence and severity of HO after TAF.

Acetabulum↗

A review of the treatment of hip dislocations associated with acetabular fractures.

Traumatic dislocation of the hip is an extremely severe injury. Although previously considered an uncommon lesion, it now is seen more often as a result of motor vehicle accidents. In most cases, dislocation of the hip is associated with fractures of the acetabulum, which ultimately can result in a higher incidence of complications than the complications observed in pure simple dislocations. Early recognition and prompt closed reduction of the dislocated hip constitute the cornerstone of proper treatment of this injury. Once the dislocation is reduced, definitive treatment of the acetabular fracture can be delayed to obtain a precise diagnostic evaluation. If surgical reconstruction of the acetabular fracture is indicated, it is done best in the first 10 days after the injury. A few patients in whom nonconcentric reduction, failed closed reduction, or impaired neurologic status occurs after reduction will require early open reduction and internal fixation of the fracture. Complications can be caused by the initial injury or by the treatment. Avascular necrosis of the femoral head, degenerative osteoarthritis, and heterotopic ossification are the main complications encountered in patients with unsatisfactory final results. Despite a perfect reduction of the hip dislocation and anatomic reduction of the acetabular fracture, a significant degenerative process of the hip is expected when the patient is assessed at long-term followup.

Acetabulum↗

Functional outcome of patients with femoral head fractures associated with hip dislocations.

Fracture of the femoral head after hip dislocation is a relatively rare injury often associated with a poor functional outcome. Twenty-six patients who sustained femoral head fractures were evaluated using radiographs, clinical examinations, and a validated outcome scoring system. The Short Form-12 was used to assess functional outcome. Patients whose fractures were stabilized with 3-mm cannulated screws and washers had a poor functional outcome. When evaluated with an odds ratio analysis, the use of Kocher-Langenbeck posterior approach was associated with a 3.2 times higher incidence of the patients having avascular necrosis develop when compared with the Smith-Petersen approach. A literature review combined with the current series confirms that the principles of early reduction of hip dislocation, early stabilization, anatomic reduction of the fracture, and rigid fixation are critical principles to attain good results. The Brumback classification system provides superior differentiation of different fracture types when compared with the Pipkin classification. The Smith-Petersen anterior surgical approach is recommended for the majority of patients with femoral head fractures. Three-millimeter cannulated screws with threaded washers are contraindicated for use in stabilizing femoral head fractures, and should not be used in any joint because of dissociation between the screw and the washer.

Adolescent↗

Acetabular fracture patterns: associations with motor vehicle crash information.

BACKGROUND: Motor vehicle crashes are the most common cause of acetabular fractures, which have been associated with significant morbidity and mortality. METHODS: To date, medical and collision information has been collected on 83 acetabular fracture patients treated at the University of Alabama at Birmingham's Level I trauma center. The fractures were grouped according to the Judet-Letournel classification scheme and investigated for correlation with age, sex, vehicle type, impact direction, and seat-belt use. RESULTS: The database included 41 women and 42 men with a combined average age of 32.8 years. Femoral shaft axis loading fractures correlated significantly with male sex, trucks, and frontal impacts. Greater trochanter loading fractures occurred statistically more frequently in side impacts. Women received a significant higher percentage of off-axis loading fractures, which were associated more in angled frontal impacts. CONCLUSION: Acetabular fracture type strongly correlated with impact direction, supporting the fracture mechanisms proposed by Judet and Letournel.

Accidents, Traffic↗

Controversies in acetabular fractures.

Open reduction and internal fixation has become the standard of care for the treatment of most displaced acetabular fractures. As surgical techniques have become refined, long term results of surgical fixation have improved. During the past 10 to 15 years, several controversies have surfaced in the orthopaedic literature regarding the treatment of acetabular fractures. The recent literature regarding acetabular fixation was reviewed. Controversies include the most efficacious surgical approach for complex acetabular fractures; the effectiveness of intraoperative sciatic nerve monitoring; the most effective method of prophylaxis against deep vein thrombosis; and the indications for and method of prophylaxis against heterotopic bone formation.

Acetabulum↗

The management of complex orthopedic injuries.

As advancements are made in the prevention of automobile fatalities, an increase in the incidence of pelvic and lower extremity injuries has occurred. These remain the leading causes of impairment and loss of years of productive life. Pelvic trauma has a high initial mortality rate when severe. However, with early resuscitation and transport, more survivors arrive in our trauma centers harboring these injuries. Owing to early stabilization and mobilization of the traumatized patient, a decrease in complications in these patients has been noted. Both the trauma surgeon and the orthopedic trauma surgeon should work as a team and remain in continuous communication during the treatment of these patients. Open fractures are among the most difficult problems to manage; early and aggressive decisions can prevent a lifetime of complications and physical impairment. As previously stated, to obtain good outcomes, open fractures must be treated initially at the accident scene followed by timely transport to the trauma center for definitive care. It must be remembered that the golden time to prevent major complications is 6 hours. Intra-articular fractures of the lower extremity involve a major weight bearing joint. Post-traumatic arthritis and impairment develop in joints where joint congruity is not achieved. To preserve normal function, there should be articular congruity, stable fixation, axial alignment with the rest of the extremity, and restoration of full range of motion. Immediate stabilization of long bone fractures has many advantages in the multiply injured patient, such as improved long-term function, prevention of deep venous thrombosis and decubitus ulcer, decreased need for analgesia, and reduction in the incidence of adult respiratory distress syndrome and fat emboli. Patients with femoral shaft fractures should undergo immediate stabilization of the fracture within 24 hours of injury. We have presented a series of orthopedic injuries that have high mortality and high morbidity which, if not treated expediently, yield a high degree of impairment.

Debridement↗

Extended iliofemoral versus triradiate approaches in management of associated acetabular fractures.

From July 1988 to June 1991, 110 complex acetabular fractures were operatively treated. A triradiate approach was used in 38 patients and an extended iliofemoral approach in 21. The mean patient age was 32 years (range, 15-80 years). These 59 patients were followed for a minimum of 36 months postoperatively. The postoperative function state was evaluated according to D'Aubigne/Postel, and the results were: Excellent, 32 patients (54%); Very Good, 10 (17%); Good, 5 (8%); Fair, 4 (7%); and Poor, 8 (14%). Adequacy of acetabular reconstruction was evaluated from the anteroposterior, obturator oblique, and iliac oblique radiographs. All patients had excellent or good radiographic results (< 2 mm step off or gap). Iatrogenic sciatic nerve injury was seen in two patients with the triradiate and one with the extended iliofemoral approach. Deep infection was seen in one patient in the extended iliofemoral group and two in the triradiate group. Eight patients developed heterotopic ossification of Brooker Grade III or IV despite prophylactic treatment with indomethacin. Both approaches provided good visualization of complex acetabular fractures.

Acetabulum↗

Bridging bone gaps with the Ilizarov technique. Biologic principles.

For the treatment of bone gaps of less than 4 cm, cancellous autografting remains the treatment of choice. But for gaps exceeding 4 cm, the distraction osteogenesis is a viable option. The following conditions should be satisfied: (1) patient selection; (2) stable fixation; (3) osteotomy by corticotomy; (4) 7- to 14-day latency period before initiating distraction; and (5) a controlled rate and rhythm of distraction of 1 mm per day (0.25 mm, four times a day). This type of treatment leaves the pathologic focus alone, and bone healing occurs on the healthy bone. The quality of bone regenerate may be improved by a motorized unit and by better soft-tissue coverage using early grafts and flaps. Interface healing is probably improved by cancellous grafting and internal fixation after the transport period, thus decreasing the fixator time.

Bone Lengthening↗

External fixation of the femur.

External fixation of the femur remains a viable option in the acute treatment of fractures or in reconstructive procedures. As in any method of fixation, the surgeon must be familiar with the device used, the mechanical properties of the device, the application technique of such devices, and, most importantly, the postoperative management of the patient.

Bone Nails↗

The use of the Ilizarov concept with the AO/ASIF tubular fixateur in the treatment of segmental defects.

For the treatment of segmental defects of less than 4 cm, cancellous autografting remains the treatment of choice. Pedicled or free cortical grafts (fibula, ribs, iliac crest) often are not strong enough, particularly when used in the femur. Allografts, especially appealing because of the theoretic unlimited supply, should not be considered for segmental diaphyseal defects because they remain dead spacers, remodelled only very slowly and incompletely, and are often complicated by late infection. The technique of distraction histogenesis used by Putti and Anderson, improved and further differentiated towards corticotomy and fragment transport by Ilizarov, is a further possibility of treating long, segmental bone defects. Already clinical and experimental data clearly show that the effect of distraction histogenesis can be obtained using many different types of external fixators. Therefore, we should use as simple a fixator construction as possible. The standard unilateral sagittal frame we suggest is derived from a two-tube AO fixator using only a few additional elements. The majority of cases with segmental defects and minor additional axial or rotational deformities (which can be corrected primarily) can be treated with such a fixator. The quality of the regenerate may be improved with a motorized, continuous transport system and by better soft-tissue coverage using early flaps. Interface healing is very probably improved by cancellous grafting and internal fixation after the transport period, thus decreasing the fixator time.

Bone Lengthening↗

Closed interlocking nailing of the femur complicated by an intramedullary calcified lesion.

The interlocking intramedullary nail has greatly expanded the indications for closed intramedullary nailing of the femur. We describe a complication caused by the presence of a calcified lesion located at the proximal metaphyseal-diaphyseal junction of the femur. This lesion could not be penetrated by hand reamers. We used a long 3.5-mm drill bit to place a hole in the infarct, which then allowed passage of the hand reamer. The operation then proceeded in the standard fashion without complications.

Adult↗

The Altdorf hip clamp.

Forty-one osteotomies internally fixed with the Altdorf hip clamp were reviewed at Nemours Children's Hospital (Jacksonville, FL). They were divided according to pathology: cerebral palsy, 19 patients; congenital dislocated hip, 2 patients; Legg-Calvé-Perthes disease, 8 patients; and other, 2 patients. There were 15 boys and 18 girls, with an average age of 6.9 years (range 2.6-12 years). No intraoperative complications have been reported. Long-term complications are as follows: nonunion, one patient; superficial wound infection, one patient; and loss of position of greater than 15 degrees, two patients.

Cerebral Palsy↗

The etiology of valgus angulation after metaphyseal fractures of the tibia in children.

We conducted a retrospective study of proximal metaphyseal fractures of the tibia in children who developed valgus deformities. We reviewed the cases in an effort to determine the most likely etiology of post-fracture tibia valga, which occurs despite careful treatment and follow-up. We reviewed seven major theories presented in the literature regarding the etiology of this problem. Our conclusion was that all the theories were not prerequisites for the development of valgus angulation, but rather may be secondary mechanisms. We suggest that the most likely primary mechanism is an increased vascular response causing an asymmetric growth stimulation of the medial metaphysis of the proximal tibia.

Child↗