RESUMO
OBJECTIVES: This study aimed at comparing the results obtained with a sliding screw plate and an experimental device including a small-diameter nail that can be placed with a mini-invasive approach and provides a stable fixation. DESIGN: Randomized prospective study. SETTING: University hospital. PATIENTS: The study included two groups with thirty fractures of the trochanteric area. INTERVENTIONS: In both groups, the surgical procedure was carried out on patients placed on a traction table in a supine position, under an x-ray amplifier. Sliding screw plates (THS) were set in place according to the usual open technique. Nails were placed through a twenty-millimeter supratrochanteric cutaneous incision. This experimental system comprised a locked intramedullary nail with two nonparallel seven-millimeter cervicocephalic screws. MAIN OUTCOME MEASURES: The comparison between the two groups was based on the surgical procedure (time, duration of x-ray irradiation, and total blood loss); the initial postoperative period (complications, duration of hospital stay, and the time before returning home); the time before full weight bearing became effective; the functional and social recovery; mortality; and the quality of immediate and final anatomic restitution and healing. RESULTS: Operating time (p < 0.001) and blood loss (p < 0.001) were lower in the nail group, and no blood transfusion was required. Postoperative pain (p < 0.01), time necessary to support full weight bearing (p < 0.02), and time before returning home (p < 0.05) were reduced in the nail group. All fractures healed in the same amount of time, with good anatomic results in the nail group, whereas ten impactions beyond ten millimeters occurred in the plate group. No difference was found between the two groups in walking ability and autonomy recovery, but hip function (p < 0.05) was better in the nail group. CONCLUSION: This preliminary clinical study has shown the advantages of this mini-invasive technique. It could not evaluate all the possible disadvantages inherent in the method. These points will be evaluated in a multicenter study justified by these preliminary results.
Assuntos
Fixação Interna de Fraturas/instrumentação , Fixação Intramedular de Fraturas/instrumentação , Fraturas do Quadril/cirurgia , Idoso , Idoso de 80 Anos ou mais , Pinos Ortopédicos , Parafusos Ósseos , Feminino , Seguimentos , Fixação Interna de Fraturas/métodos , Fixação Intramedular de Fraturas/métodos , Consolidação da Fratura/fisiologia , Fraturas do Quadril/diagnóstico por imagem , Humanos , Masculino , Procedimentos Cirúrgicos Minimamente Invasivos/instrumentação , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Probabilidade , Radiografia , Amplitude de Movimento Articular , Resultado do TratamentoRESUMO
OBJECTIVE: This study sought to identify the long-term functional results of various posterior pelvic lesions and to determine whether such injuries benefit from exact reduction. DESIGN: Consecutive cohort of patients admitted for pelvic disruption between 1980 and 1990. SETTING: University hospital. PATIENTS: Eighty-eight pelvic fractures in eighty-eight patients were classified according to the instability and anatomy of the posterior injury. Simple fractures of the pubic rami, minimally displaced fractures with pubic diastasis of less than 2.5 centimeters, and fractures without other pelvic lesions (type B1 lesions, stage 1 in the Tile classification) were all excluded. Patients with sequelae of associated lesions that could render functional evaluation difficult were also excluded. INTERVENTIONS: The initial status of the patient and the type of fracture determined the treatment. In the anteroposterior compression injuries group, an external fixator using the double-frame Hoffmann device was applied in twenty-eight cases to reduce a large external horizontal displacement, either immediately to control bleeding or later as definitive treatment when anterior internal fixation was not possible. Anterior internal fixation with a plate was used six times to repair a symphyseal disruption. In vertical shear injuries, tibial skeletal traction was used for six weeks as an attempt to stabilize vertical instability. In ten patients, traction alone was used. In other cases, traction was used in conjunction with an external fixator or internal pubic fixation. In impacted lateral compression injuries, simple bed rest for six weeks was used in cases of stable lesions. Skeletal traction was applied in ten patients of this group because of a potential vertical instability, particularly in cases with a comminuted sacral lesion. MAIN OUTCOME MEASURES: Anatomic diagnosis and evaluation of the reduction were made using anteroposterior, inlet, and outlet radiographs of the pelvic ring. To assess reduction, vertical, anteroposterior, and rotatory displacement was measured. Functional results were qualified based on the injury pattern and the quality of the final reduction and were then quantified according to the grading proposed by Majeed. RESULTS: Functional results varied according to injury anatomy, with fractures of the iliac wing and sacroiliac (SI) fracture-dislocations having the best prognosis. The quality of reduction did not affect the functional results. Conservative methods such as skeletal traction and external fixation generally gave satisfactory functional results. Conversely, however, pure SI lesions were associated with poor functional results, especially if reduction was not exact. CONCLUSIONS: This study shows that when the posterior injury is a fracture of the iliac wing or a mixed fracture with SI propagation, a long-term satisfactory functional result can be obtained without an exact reduction even in cases of vertical instability. Simple methods are usually sufficient, and it seems unnecessary to propose more aggressive treatment. It is important, however, to recognize that SI fracture-dislocations (17 percent in this series) seem to be quite different from pure SI disruptions in terms of persistent pain. Moreover, it appears that exact reduction of pure SI lesions is critical for good functional results, something that is difficult to obtain with conservative procedures. Sacral fractures represent a special problem for the surgeon because of the frequency of fair results in which neurologic lesions whose pathophysiology is poorly known seem to be responsible.
Assuntos
Fraturas Ósseas/diagnóstico , Ossos Pélvicos/lesões , Adolescente , Adulto , Idoso , Feminino , Fixação de Fratura , Fixação Interna de Fraturas , Fraturas Ósseas/fisiopatologia , Fraturas Ósseas/terapia , Humanos , Ílio/lesões , Luxações Articulares/diagnóstico , Luxações Articulares/terapia , Masculino , Pessoa de Meia-Idade , Ossos Pélvicos/diagnóstico por imagem , Prognóstico , Sínfise Pubiana/cirurgia , Radiografia , Sacro/lesões , Tração , Resultado do TratamentoRESUMO
In orthopaedic clinical studies, quantitative X-ray bone densitometric analysis could provide precise means of detecting alterations within the bone. With duel-energy X-ray absorptiometry and diphotonic absorptiometry precise and reproducible measures are possible, but they require a specific and costly examination. The use of routine and past available radiographs could facilitate long-term follow-up retrospective studies, but when femoral X-ray bone density is assessed by the naked eye on conventional radiographs, the percentage of errors may be very high (80%). The advantage of a method using conventional radiographs has led us to look for an original technology to estimate X-ray bone density from routine radiographs using both soft tissues and prostheses as X-ray absorptiometric phantoms. In theory, this calculation requires several approximations. An experimental study based on 40 subjects aimed at determining the rate of error due to these approximations. Three radiographs were made for every subject with very different exposure settings. They were computerized by a CCD camera to measure the grey levels (256 scale) of soft tissue and prosthesis, as well as variations in contrast. The statistical analysis showed that when comparing X-ray bone density on different routine radiographs, the percentage of error could be lower than 10% but only under these conditions: (a) grey levels of soft tissue > 26; (b) grey levels of prosthesis < 212; (c) variation of contrast between radiographs > 0.79; (d) radiographs made with the same incidence, and (e) weight of the subject remaining constant during the whole period. It therefore seems possible to compare retrospectively the cortical X-ray bone density from routine radiographs, and to quantify bone remodelling around total hip arthroplasty, but only for the same subject.
Assuntos
Remodelação Óssea/fisiologia , Prótese de Quadril , Absorciometria de Fóton , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biofísicos , Biofísica , Densidade Óssea , Feminino , Fêmur/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Imagens de FantasmasRESUMO
We report a patient who sustained a displaced fracture of the lunate in association with fractures of the scaphoid and capitate. Union of the scaphoid and capitate fractures followed fixation with Herbert screws, 25 additional cases from the literature have been reviewed.
Assuntos
Ossos do Carpo/lesões , Fraturas Ósseas/diagnóstico por imagem , Osso Semilunar/lesões , Adulto , Parafusos Ósseos , Fixação Interna de Fraturas , Fraturas Ósseas/epidemiologia , Fraturas Ósseas/cirurgia , Humanos , Masculino , Radiografia , SíndromeRESUMO
The use of antibiotics in 480 cases in 4 hospital wards during 1988 was assessed by examination of medical records. Only the first antibiotic therapy administered during the first stay in the ward for each patient was included. Antibiotics were administered to 163 in-patients (37% of hospitalizations) for infections in 113 (26%) cases. Amoxycillin and macrolides were the drugs most frequently used. Sixty-eight percent of the treatments were administered in the absence of microbiological data. Single drug therapy was used in 60% of treatments. Fifty in-patients (11% overall; 41% of patients undergoing surgery) received antibiotics for prophylaxis. The exact indication(s) for the choice of therapy was not given in the medical records of 39% of cases. Treatment started within 48 hours of infection in 15% of the cases. Overall, 93% of the treatments given were indicated, but 53% were inappropriate because they were too expensive, unlikely to be effective or were multiple drug therapy without justification. There are a variety of factors that cause such inappropriate administration of antibiotics.
Assuntos
Antibacterianos/uso terapêutico , Infecções Bacterianas/tratamento farmacológico , Adulto , Idoso , Análise de Variância , Distribuição de Qui-Quadrado , Intervalos de Confiança , Quimioterapia Combinada/uso terapêutico , Uso de Medicamentos , Feminino , Mau Uso de Serviços de Saúde , Departamentos Hospitalares , Humanos , Masculino , Pessoa de Meia-Idade , Análise de RegressãoRESUMO
Gaucher's disease is a sphingolipidosis which may be accompanied by severe pain in the bones. We report a case of Bacteroides fragilis osteomyelitis consecutive to surgical biopsy. The bone pain may be due to ischaemia of the bone or to a pyogenic osteomyelitis which is iatrogenic in most cases. The clinical and paraclinical features of these two entities are described after a review of the literature, and the main complementary examinations leading to their diagnosis are presented.
Assuntos
Doença de Gaucher/complicações , Osteomielite/etiologia , Adulto , Antibacterianos , Infecções por Bacteroides/tratamento farmacológico , Infecções por Bacteroides/microbiologia , Bacteroides fragilis/isolamento & purificação , Quimioterapia Combinada/uso terapêutico , Humanos , Imageamento por Ressonância Magnética , Masculino , Osteomielite/diagnóstico por imagem , Osteomielite/tratamento farmacológico , Osteomielite/microbiologia , Tomografia Computadorizada por Raios XRESUMO
A patient with bilateral traumatic hypoglossal palsy is presented. Evaluation of the atlanto-occipital articulation is difficult. Prompt radiographic diagnosis of this injury can be made by computed tomography. In this case, there was bony avulsion of the alar ligament from the occipital condyle. We suggest a severe blow to the head in a lateral direction.
Assuntos
Traumatismos Craniocerebrais/complicações , Nervo Hipoglosso , Paralisia/etiologia , Adulto , Doenças dos Nervos Cranianos/etiologia , Traumatismos Craniocerebrais/diagnóstico por imagem , Humanos , Masculino , Tomografia Computadorizada por Raios XRESUMO
The authors have observed four cases of a rare condition of fracture-dislocation of the calcaneus. The fracture line was in the sagittal plane and there were only two fragments. An anterior and medial fragment maintained its normal relationship with the talus whilst the posterior and lateral fragment became dislocated laterally underneath the fibular malleolus. Treatment should always be surgical by open reduction and screw fixation. Two cases out of four were not operated upon and these have poor results.
Assuntos
Calcâneo/lesões , Fraturas Ósseas/complicações , Luxações Articulares/complicações , Adulto , Feminino , Fixação Interna de Fraturas , Fraturas Ósseas/diagnóstico por imagem , Fraturas Ósseas/cirurgia , Humanos , Luxações Articulares/diagnóstico por imagem , Luxações Articulares/cirurgia , Masculino , Pessoa de Meia-Idade , RadiografiaRESUMO
180 comminuted fractures of the trochanteric region in elderly patients were fixed by nail-plates with some degree of upward displacement of the shaft and impaction. 81 p. 100 of the patients were allowed to bear full weight soon after the operation. Severe secondary displacement was observed in only 2.7 p. 100. This technique makes nursing easier and hospitalisation shorter. Some details of the mechanical basis and the technique of operation are given.
Assuntos
Fixação Interna de Fraturas , Fraturas do Quadril/cirurgia , Idoso , Infecções Bacterianas/etiologia , Pinos Ortopédicos , Placas Ósseas , Fixação Interna de Fraturas/métodos , Fraturas do Quadril/mortalidade , Humanos , Pessoa de Meia-Idade , Complicações Pós-OperatóriasRESUMO
Twenty-seven patients with complex fractures of the lower end of the tibia were treated by an external Hoffman fixator between 1977 and 1981. Its use was inspired by the presence of skin lesions and by the anatomical type of fracture when it was felt that other methods of treatment would be ineffective or hazardous. In favour of the method was the absence of iatrogenic infection and anatomical results that were superior to those of conservative treatment. Against it, there was a longer time for union, with eight delayed unions and three non-unions and the fact that it was impossible to correct joint impaction which was present in 14 out of 28 cases.
Assuntos
Dispositivos de Fixação Ortopédica , Fraturas da Tíbia/cirurgia , Adolescente , Adulto , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , Fraturas da Tíbia/classificação , Fraturas da Tíbia/diagnóstico por imagem , CicatrizaçãoRESUMO
In order to be able to evaluate the mechanical properties of cortical and sub-cortical bone from a radiologic acquisition, the authors have researched a link between the X-rays transparency of bone and its hardness. A device for measuring hardness has been developed which allows an almost punctual evaluation of the mechanic value of bone. This value has been compared with X-rays transparency of the studied point. The link found between these two variables on 80 measures was strong, with signification less than 0.001.
Assuntos
Fêmur/diagnóstico por imagem , Dureza , Fenômenos Biomecânicos , Elasticidade , Fêmur/fisiologia , Humanos , Tomografia Computadorizada por Raios XRESUMO
Twenty-five tibial shaft fractures were treated by primary Hoffman external fixation and secondary locked nailing with reaming. The indications were: aseptic non union (12 cases) and the original plan of treatment (13 cases) (early delayed nailing). The septic risk factors were the initial opening of the fracture site (19 sites) and, in all cases, the pin-tracts with, in 5 cases, an intolerance to pins marked by a drainage or an osteolysis. Union was achieved in the 25 cases in an average time of 3.3 months. The restoration of alignment was anatomic in 19 cases. The risk of infection was confirmed with the onset of 4 deep infections which occurred each time when risk factors existed: prolonged bone exposure and intolerance to pins. Infection was treated by a selected antibiotherapy with the nail kept in place and union was obtained primarily: secondary removal of the nail was necessary in 2 cases to obtain drying up. The risk of infection after secondary nailing has thus been confirmed but its frequency and severity didn't appear excessive when compared to the advantages of locked intramedullary nailing.
Assuntos
Fixadores Externos , Fixação Intramedular de Fraturas/métodos , Fraturas da Tíbia/cirurgia , Infecções Bacterianas/etiologia , Feminino , Fixação Intramedular de Fraturas/efeitos adversos , Humanos , Masculino , Reoperação , Fatores de Risco , Fatores de TempoRESUMO
Five hundred and six patients aged 60 years or over admitted to hospital between 1977 and 1982 for a fracture of the upper end of the femur were the subject of a retrospective study to determine their mortality. Those with multiple injuries or affected by a pathological fracture were excluded. The median age of the population was 80 years, with a clear female predominance. Ageing appeared to be the main risk factor in fracture of the upper end of the femur. Surgical treatment was early, at a median of two days, and weightbearing was possible on the fifth day for half of the patients. The mean time in the surgical department was 15 days, followed by transfer to a nursing home or to a rehabilitation unit for two-thirds of the patients; 7.9 p. cent of patients died during their stay in the surgical department. The actuarial survival rate at one year was 64.7 p. cent and at five years was 35.3 per cent. Compared with the corresponding general population, a fracture of the upper end of the femur is accompanied by a persistently higher mortality for at least two years after the accident, more marked in relative values in men and in younger subjects. A multifactorial study of the prognostic factors using Cox's model showed that the mortality rose with age at the time of the fracture but was lower when the patient had previously been able to go out of the house and was of the female sex.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Cabeça do Fêmur/lesões , Fraturas do Quadril/mortalidade , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Feminino , Fraturas do Quadril/etiologia , Fraturas do Quadril/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Fatores de RiscoRESUMO
Among the hypothesis about pathogenesis of medial knee osteoarthritis, the participation of modifications of the alignment of the limb in the frontal plane is known. The participation of the femoral and tibial torsions had been assessed by a few authors. In this study, the torsions have been measured by computerized tomodensitometry. The global torsional morphology of the limb has been defined by the measure of the Index of Cumulated Torsions. The values of torsions have been compared with the angle deformities measured in the frontal plane. The effects of the bone torsions on the position of the lower limb during the weight-bearing phase of the gait and the consequences about the knee have been studied.
Assuntos
Articulação do Joelho , Osteoartrite/etiologia , Idoso , Feminino , Fêmur/fisiopatologia , Humanos , Articulação do Joelho/fisiopatologia , Masculino , Pessoa de Meia-Idade , Osteoartrite/fisiopatologia , Tíbia/fisiopatologia , Anormalidade Torcional/complicações , Anormalidade Torcional/fisiopatologiaRESUMO
Complex fractures of the femoral shaft rise problems due to high energy trauma with major soft-tissues injuries and bone comminution so increasing operative difficulties, risk of infection and delayed union. Our aim was to appraise the outcome of these problems when using a closed intramedullary locked nailing. There were 52 men and 16 women. Aged 16 to 83 years. 52 patients had multiple-injuries. There were 17 open fractures. The 68 cases were subdivided according to a classification in 3 types. Stable fractures type A and B1 were excluded. The shaft was divided into 5 zones. Patients were initially treated by skeletal traction closed nailing was performed 1-36 days later (average 9.5). All patients were reviewed until complete healing. Final follow-up was 6 to 35 months postoperatively (average 15). A dynamisation was performed in 19 cases at a average delay of 12 weeks. Sixty six of the 68 fractures united. Open fractures united after 26.4 weeks, in average and closed fractures after 23.25 weeks (p < .05). There was no correlation between time of surgery following the injury and the delay of healing. Shortening was noted in 4 cases. 8 patients had an angulation 5-15 degrees of in the varus or the valgus plane. 3 patients (4.4 per cent) had more than 5 degrees of angulation in the AP plane. An external rotation deformity of 10-35 degrees was noted in 4 patients. The incidence of deformities was the main problem. It could be minimize by a precise technique. Mobility of the knee was the other problem, but it appeared generally to depend much more on knee injury than on femoral fracture.
Assuntos
Pinos Ortopédicos , Fraturas do Fêmur/cirurgia , Fixação Intramedular de Fraturas , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Pinos Ortopédicos/efeitos adversos , Feminino , Seguimentos , Fixação Intramedular de Fraturas/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Tração/efeitos adversosRESUMO
Tectoplasty was performed 10 times on adult dysplasic hips with advanced secondary OA for which femoral osteotomy could be considered. The 5 hips with pre-operative osteoarthritis staged IV according to De Mourgues scale and 3 of the 5 hips pre-operatively staged III displayed at maximal follow-up (on an average of 9.6 years), improvement of the radiographic articular space. The other 2 hips showed a stabilization of the x-ray osteoarthritis. Clinical improvement with an average gain of 2.5 points according to Merle d'Aubigné scale was always noted along with these improvements or these x-ray stabilizations.
Assuntos
Osteoartrite do Quadril/cirurgia , Adulto , Transplante Ósseo , Feminino , Seguimentos , Humanos , Masculino , Métodos , Pessoa de Meia-Idade , Osteoartrite do Quadril/complicações , Osteoartrite do Quadril/diagnóstico por imagem , Radiografia , Fatores de TempoRESUMO
INTRODUCTION: In cases of severe hip osteoarthritis in young patients, the intertrochanteric osteotomy can delay total hip arthroplasty. The main advantage of the osteotomy is to preserve the bone stock. The main disadvantages are the lasting postoperative invalidity and the varying longterm success rate. Our aim was to quantify these disadvantages using survivorship analysis. MATERIAL AND METHODS: The study included 64 patients (65 osteotomies) ranging from 16 to 68 years. The osteotomies were performed between 1975 and 1987. The osteoarthritis was stage III or IV, with a joint space less than 50 per cent. Osteoarthritis was primitive in 25 cases and secondary in the others. The osteotomy always included a medial displacement of the shaft according to the principle of Mac Murray's procedure, but also 22 cases (33.8 per cent) had a varus angulation and 19 (29.2 per cent) a valgus angulation. The preoperative pain score according to the Merle d'Aubigné (MDA) grading was 2.6 (1 to 4) and the global functional score was 11.1 (5 to 15). The patients were reviewed in 1991 and examined clinically and radiographically. RESULTS: The results of the 65 cases were distributed into 3 groups: -29 cases having reached the follow-up without difficulty, -7 patients were lost for follow-up examination, 6 of these latter than 9 years, -29 patients taking osteotomy failure as a pain lesser than the 3 MDA score. The postoperative delay to obtain the best functional result was 6 to 24 months (mean: 13.65). This result ranged from 5 to 17 MDA score (mean: 15) with pain ranging from 2 to 6 (mean: 5). The survivorship analysis curve showed 67.5 +/- 19.5 per cent survival for all osteotomies to the interval of 9-10 years. There were 3 types of results: -3 early failures (4.6 per cent) one because of a deep infection, -in 7 cases, after a short initial functional improvement, there was a progressive degradation leading to failure in 3.7 years (2 to 6 years), -55 cases with a lasting period of functional improvement, 26 osteotomies leading to failure in 3.5 to 15 postoperative years and, 29 cases having reached the follow-up (7 to 16 years mean 10 years). There was radiographic improvement of the osteoarthritis increasing the joint space in 59 cases (90.7 per cent). There was no radiographic improvement in the 6 other cases, including the 2 functional failures. The functional degradation appeared parallel to the radiographic degradation leading to a decrease of joint space to 90 per cent. We tested differences between various groups using Log Rank test. We found no difference in survival between the 3 different types of osteotomy. DISCUSSION: The results of this study can help to choose between intertrochanteric osteotomy and THA in the case of severe osteoarthritis. The best functional result of the osteotomy is in one postoperative year, with a mean MDA score of 15 and a mean pain score of 5. It appears that we do not predict the duration of functional improvement, the patient has 2/3 chances that this improvement reaches 10 years.
Assuntos
Fêmur/cirurgia , Osteoartrite do Quadril/cirurgia , Osteotomia/métodos , Análise Atuarial , Adolescente , Adulto , Idoso , Pinos Ortopédicos , Placas Ósseas , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite do Quadril/diagnóstico por imagem , Osteotomia/efeitos adversos , RadiografiaRESUMO
The authors have performed the Insall procedure on 30 knees since 1981. The results are analysed with a minimum of one year follow-up. The procedure, which is an active transfer of the iliotibial tract to the tibial plateau is based on the action of the proprioceptive structure of the muscles of the thigh. It produced a decrease of 50 p. 100 in the anterior drawer sign, the Lackman test disappeared in two thirds of the cases and the pivot-shift test disappeared in four knees out of five. Twenty-two patients engaged in some kind of sport before their accident; 17 were able to practice their sport at the same level after the operation. The results as evaluated by the CLAS system were good in 23, fair in five and poor in two. The indications are discussed and the results compared with those obtained after other procedures. This procedure should be performed on patients suffering disabling instability in daily life with a marked anterior drawer sign, but who are not high level athletes. The technical details are given. The transfer should be sufficiently massive, solid and well vascularised. The lateral stability of the knee should not be impaired by the procedure.
Assuntos
Fascia Lata/cirurgia , Fasciotomia , Instabilidade Articular/cirurgia , Articulação do Joelho/cirurgia , Ligamentos Articulares/cirurgia , Doença Crônica , Seguimentos , Humanos , Fatores de TempoRESUMO
To improve the contribution of the radio ulnaris superior joint to the unrolling of pronation supination motion, we have set an anatomical and functional study with 20 cadaveric forearms. The first part concerned measures of the radial head diameters, which confirm its constant ovality, nevertheless unsufficient to create a "cam effect" likely to permit the passage of tuberositas radii over the ulna. The second part was supposed to evaluate the modifications of the pronation supination amplitude with fixed ulna, following radial head resection and prosthetic replacement. This study permitted to obtain relatively equivalent graphs in these circumstances; the prosthetic group realises the most important average range of motion, and graphics with the most approximating isocentrical arc of circles aspect. As a conclusion, no experimental argument seemed sufficient for us, to make a better choice between radial head resection and prosthetic replacement.
Assuntos
Pronação/fisiologia , Próteses e Implantes , Rádio (Anatomia)/anatomia & histologia , Supinação/fisiologia , Idoso , Idoso de 80 Anos ou mais , Cadáver , Feminino , Humanos , Masculino , Rádio (Anatomia)/cirurgiaRESUMO
PURPOSE OF THE STUDY: The major problem in external fixation of upper metaphyseal tibial fractures with a double-frame Hoffmann device is poor healing. With a dynamic fixation, it would be possible, with no change in technique, to compress the fracture site in a second phase, and therefore to facilitate the healing process. However, a new fixation device should not compromise the primary stability of the fixation. The aim of this experimental study on cadavers was to compare, in conditions very close to a clinical situation, the initial stabilization capability of five types of external fixation. MATERIAL: Five types of external fixators were tested on cadavers specimens: 1. a standard double-frame Hoffmann device; 2. a double-frame Hoffmann's device sagittaly reinforced with two additional anterior-posterior half-pins; 3. a type-1 axial dynamic fixation device using 6-mm conical pins; 4.a type-2 dynamic axial fixation device with 5-mm cylindrical pins; and 5. a mixed device including an lizarov-type epiphyseal fixation and a monoplane diaphyseal fixation. METHODS: The metaphyseal fracture was simulated by a transversal resection of a 20-mm segment. Specimens received by increments a load of up to 310 N, with which it was possible to determine stiffness components in valgus/varus, flexion/extension, rotation around the vertical axis and axial vertical displacement. The bone mineral content of the specimens was measured by Di Energy X-ray Absorptiometry. RESULTS: The stabilization characteristics of type-1 axial dynamic fixation were identical to those of the standard Hofmann's device in flexion/extension and in rotation as well as axially, but a greater mobility in valgus/varus was observed. The sagittal reinforcement of Hoffmann's device increased its rigidity in flexion/extension. The mixed lizarov fixation was stiffer than the standard Hoffmann's device in rotation; it was equivalent in valgus/varus and flexion/extension and less stiff in axial vertical displacement. In this study it was showed that the individual variability of bone mineral content is a negligible parameter. DISCUSSION: The experimental behaviour of the mixed Ilizarov device gives to assume that it may facilitate the healing process without endangering the primary stability of the fixation. However, this theoretical advantage should be validated in a randomized prospective clinical study.