RESUMEN
Despite worldwide clinical use of bio-absorbable devices for internal fixation in orthopaedic surgery, the degradation behaviour and tissue replacement of these implants are not fully understood. In a long-term experimental study, we have determined the patterns of tissue restoration 36 and 54 months after implantation of polyglycolic acid and poly-laevo-lactic acid screws in the distal femur of the rabbit. After 36 months in the polyglycolic acid group the specimens showed no remaining polymer and loose connective tissue occupied 80% of the screw track. Tissue restoration remained poor at 54 months, the amounts of trabecular bone and haematopoietic elements being significantly lower than those in the intact control group. The amount of trabecular bone within the screw track at 54 months in the polyglycolic acid group was less than in the empty drill holes (p = 0.04). In the poly-laevo-lactic acid group, polymeric material was present in abundance after 54 months, occupying 60% of the cross-section of the core area of the screw track. When using absorbable internal fixation implants we should recognise that the degradation of the devices will probably not be accompanied by the restoration of normal trabecular bone.
Asunto(s)
Implantes Absorbibles , Regeneración Ósea , Tornillos Óseos , Ácido Láctico/análogos & derivados , Ácido Poliglicólico/química , Polímeros/química , Tejido Adiposo/patología , Animales , Materiales Biocompatibles , Huesos/patología , Tejido Conectivo/patología , Femenino , Fijación Interna de Fracturas/instrumentación , Fijación Interna de Fracturas/métodos , Hematopoyesis , Fijadores Internos , Ácido Láctico/química , Masculino , Periodo Posoperatorio , ConejosRESUMEN
Bioabsorbable internal fixation devices were introduced clinically in the treatment of fractures and osteotomies of the extremities at the Department of Orthopaedics and Traumatology, Helsinki University, in 1984. Since November 5, 1984, a total of 3200 patients were managed using bone or ligament fixation devices made of self-reinforced (matrix and fibres of the same polymer) bioabsorbable alpha-hydroxy polyesters. The devices used included cylindrical rods, screws, tacks, plugs, arrows, and wires. The most common indication for the use of bioabsorbable implants was the displaced malleolar fracture of the ankle. Transphyseal fixation with small-diameter, mainly polyglycolide pins was used in children. The postoperative clinical course was uneventful in more than 90% of the patients. The complications included bacterial wound infection in 4% and failure of fixation in 4%. In one-fifth of the latter cases, however, re-operation was not necessary. The occurrence of non-infectious foreign-body reactions two to three months postoperatively has been observed in 2% of the patients operated in the last few years with polyglycolide implants but none of the patients managed with polylactide implants. This inflammatory tissue response often required aspiration with a needle but did not influence the functional or radiologic result of the treatment. Owing to the biodegradability of these internal fixation devices, implant removal procedures were avoided. This results in financial benefits and psychological advantages. Bioabsorbable implants can also be used in open fractures and infection operations.
Asunto(s)
Implantes Absorbibles , Fijación de Fractura , Ortopedia , Heridas y Lesiones/terapia , Implantes Absorbibles/efectos adversos , Niño , Humanos , Poliésteres , Ácido Poliglicólico , Infección de la Herida QuirúrgicaRESUMEN
When the polymeric material reaches the final stages of its degradation process, biodegradable orthopaedic fixation devices elicit a local foreign-body reaction. In most cases, the symptoms of this tissue response are subclinical and pass unnoticed, but in some patients a clinically manifest inflammatory foreign-body reaction ensues. Mild clinical reactions consist of a painful erythematous papule, those of medium severity show a sinus discharging polymeric debris for up to 6 months, and in the patients affected by a severe reaction, extensive osteolytic lesions may develop at the implant tracks. The histopathologic picture is that of a non-specific foreign-body reaction. For implants made of polyglycolide, the average incidence of the manifest reactions is 5%. When slow-degrading polymers are used, the incidence is lower. The tissue responses to polyglycolide manifest themselves 11 weeks after surgery, on an average, whereas foreign-body reactions to devices made of poly-L-lactide can emerge as late as 4 or 5 yr after the original fracture fixation operation. A poorly vascularized bone section, use of a quinone dye as an additive in the polymer, and an implant geometry with large surface area each seems to be associated with an increased risk of the occurrence of a foreign-body reaction. Yet in majority of the patients affected, no known individual marker of high risk is present. Some recent laboratory experiments indicate that it may be possible to diminish the risk of an adverse tissue response by incorporating alkaline salts or antibodies to inflammatory mediators in the implants. The results of in vitro and animal experiments, however, cannot always be directly extrapolated to humans. Only large-scale long-term clinical research will ultimately show which physico-chemical characteristics of a biodegradable orthopaedic implant provide the optimal clinical biocompatibility.
Asunto(s)
Materiales Biocompatibles , Fijadores Internos , Ortopedia , Implantes Absorbibles , Materiales Biocompatibles/efectos adversos , Femenino , Reacción a Cuerpo Extraño , Humanos , Persona de Mediana EdadRESUMEN
The epidemiologic and morphologic features of all femoral shaft fractures in skeletally mature patients treated during a 10-year period in a semi-urban county were analyzed. Among an average adult population of 202,592 residents, 192 people sustained 201 traumatic femoral shaft fractures during the study period. The incidence was 9.9 fractures per 100,000 person-years. The highest age and gender specific incidences were seen in males from 15 to 24 years of age and in females 75 years of age or older. Seventy-five percent (151) of the fractures were the result of a high-energy trauma, 131 of which occurred in road traffic accidents. Unexpectedly, there were 50 low-energy fractures. Fractures of the middle 1/3 of the diaphysis were 79%. The majority, 155 (77%), of all fractures were transverse, oblique, or oblique transverse. Regarding the degree of comminution, the Winquist and Hansen Grade 0 (noncomminuted) fracture was the most common. Forty-eight percent of fractures were AO Type A, 39% were Type B, and 13% were Type C fractures. Of the 25 open fractures, 14 were Gustilo Type II. All six Type III open injuries were Type IIIA. Based on the data from the current study, most of the femoral fractures in this community might be treated adequately with conventional intramedullary nails, rather than using interlocking nails, provided the stability of fixation and fracture alignment can be maintained. Preventive measures against femoral shaft fractures should focus on protection of automobile drivers, especially young men, and on effective treatment of osteoporosis in elderly women.
Asunto(s)
Fracturas del Fémur/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Fracturas del Fémur/etiología , Fracturas del Fémur/patología , Finlandia/epidemiología , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Estaciones del AñoRESUMEN
Among 2528 patients operated on using pins, rods, bolts, and screws made of polyglycolic acid or polylactic acid, 108 (4.3%) were affected by a clinically significant local inflammatory, sterile tissue reaction. The three most common indications for the use of these fixation devices were a displaced malleolar fracture, a chevron osteotomy for hallux valgus, and a displaced fracture of the radial head. In 107 patients, the reaction was elicited by a polyglycolic acid implant, and in one patient by a polylactic acid implant. The incidences were 5.3% (107 of 2037) and 0.2% (one of 491), respectively. The adverse tissue responses to polyglycolic acid were seen 11 weeks after the operation, on average, whereas the reaction to polylactic acid occurred 4.3 years after fixation of an ankle fracture. The mild reactions consisted of a painful erythematous papule of a few weeks' duration. Those of medium severity had a sinus that discharged remnants of the implant for up to 6 months. In the patients affected by severe reactions, extensive osteolytic lesions developed at the implant tracks. The histopathologic picture was that of a nonspecific foreign body reaction. In four patients with vigorous reactions, an arthrodesis of the wrist or ankle later was necessary because of severe osteoarthritis. Several markers of increased risk of the occurrence of a foreign body reaction were found. These included a poorly vascularized bone section such as scaphoid, use of a quinone dye as an additive in the polymer, and an implant geometry with large surface area (screw versus pin or rod). For polyglycolic acid implants, the risk of an adverse tissue response in a given clinical situation can be estimated from the findings of this study. For slow degrading polymers like polylactic acid, however, the ultimate biocompatibility still is unsettled, and additional clinical research with long followup is required.
Asunto(s)
Implantes Absorbibles/efectos adversos , Reacción a Cuerpo Extraño/patología , Fijación Interna de Fracturas/instrumentación , Ácido Láctico/efectos adversos , Ácido Poliglicólico/efectos adversos , Polímeros/efectos adversos , Huesos/patología , Tejido Conectivo/patología , Estudios de Seguimiento , Humanos , Osteólisis/patología , Poliésteres , Reoperación , Factores de RiesgoRESUMEN
We reviewed 110 patients with an unstable fracture of the pelvic ring who had been treated with a trapezoidal external fixator after a mean follow-up of 4.1 years. There were eight open-book (type B1, B3-1) injuries, 62 lateral compression (type B2, B3-2) and 40 rotationally and vertically unstable (type C1-C3) injuries. The rate of complications was high with loss of reduction in 57%, malunion in 58%, nonunion in 5%, infection at the pin site in 24%, loosening of the pins in 2%, injury to the lateral femoral cutaneous nerve in 2%, and pressure sores in 3%. The external fixator failed to give and maintain a proper reduction in six of the eight open-book injuries, in 20 of the 62 lateral compression injuries, and in 38 of the 40 type-C injuries. Poor functional results were usually associated with failure of reduction and an unsatisfactory radiological appearance. In type-C injuries more than 10 mm of residual vertical displacement of the injury to the posterior pelvic ring was significantly related to poor outcome. In 14 patients in this unsatisfactory group poor functional results were also affected by associated nerve injuries. In lateral compression injuries the degree of displacement of fractures of the pubic rami caused by internal rotation of the hemipelvis was an important prognostic factor. External fixation may be useful in the acute phase of resuscitation but it is of limited value in the definitive treatment of an unstable type-C injury and in type-B open-book injuries. It is usually unnecessary in minimally displaced lateral compression injuries.
Asunto(s)
Fijadores Externos , Fracturas Óseas/cirugía , Huesos Pélvicos/lesiones , Actividades Cotidianas , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Fijadores Externos/efectos adversos , Femenino , Estudios de Seguimiento , Fijación de Fractura/efectos adversos , Curación de Fractura , Fracturas Óseas/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Dolor/etiología , Huesos Pélvicos/diagnóstico por imagen , Radiografía , Insuficiencia del TratamientoRESUMEN
A total of 1202 fractures of the ankle were treated with absorbable implants made of polyglycolide/polylactide copolymer or self-reinforced polyglycolide and/or self-reinforced polylactide between November 5, 1984, and January 12, 1994. A redisplacement after fixation was diagnosed in 30 patients (2.5%). The redisplacement occurred in 8 of 934 (0.9%) simple ankle fractures and in 22 of 268 (8.2%) severer ankle fractures. A breakage or loosening of the absorbable implant was verified at reoperation in 8 cases and was suspected in another 9. A technical failure was the main reason in 13 cases. A reoperation was performed for 25 patients. The absorbable implants seem to provide a secure fixation in the majority of ankle fractures, but the use of these implants showed unsatisfactory results in unstable and comminuted fractures.
Asunto(s)
Traumatismos del Tobillo/cirugía , Materiales Biocompatibles , Clavos Ortopédicos , Tornillos Óseos , Fijación Interna de Fracturas/instrumentación , Fracturas Óseas/cirugía , Poliésteres , Ácido Poliglicólico , Absorción , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Traumatismos del Tobillo/diagnóstico por imagen , Materiales Biocompatibles/efectos adversos , Materiales Biocompatibles/metabolismo , Biodegradación Ambiental , Niño , Femenino , Reacción a Cuerpo Extraño/etiología , Fijación Interna de Fracturas/efectos adversos , Curación de Fractura/fisiología , Fracturas Óseas/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Falla de Prótesis , Implantación de Prótesis/métodos , Radiografía , Reoperación , Estudios RetrospectivosRESUMEN
Between 1985 and 1994, 1223 patients with malleolar fractures of the ankle were treated by open reduction and internal fixation with absorbable pins and screws, of whom 74 (6.1%) had an obvious inflammatory foreign-body reaction to the implants. Of these 74, ten later developed moderate to severe osteoarthritis of the ankle despite no evidence of incongruity of the articular surface. The implants used in these patients were made from polyglycolide, polylactide or glycolide-lactide copolymer. The joint damage seemed to be due to polymeric debris entering the articular cavity through an osteolytic extension of an implant track. The ten patients had a long clinical course which included a vigorous local foreign-body reaction, synovial irritation and subsequent degeneration. At a follow-up of three to nine years, ankle arthrodesis had been necessary in two patients and is being considered for another two. The incidence of these changes in the whole series was 0.8%, which is not high, but awareness of this possible late complication is essential.
Asunto(s)
Articulación del Tobillo/patología , Clavos Ortopédicos/efectos adversos , Tornillos Óseos/efectos adversos , Reacción a Cuerpo Extraño/complicaciones , Osteoartritis/etiología , Absorción , Adulto , Materiales Biocompatibles/efectos adversos , Distribución de Chi-Cuadrado , Fístula Cutánea/etiología , Femenino , Peroné/lesiones , Estudios de Seguimiento , Reacción a Cuerpo Extraño/diagnóstico por imagen , Fijación Interna de Fracturas/efectos adversos , Fijación Interna de Fracturas/instrumentación , Curación de Fractura , Fracturas Óseas/cirugía , Humanos , Incidencia , Ácido Láctico/efectos adversos , Masculino , Persona de Mediana Edad , Osteoartritis/diagnóstico por imagen , Poliésteres/efectos adversos , Ácido Poliglicólico/efectos adversos , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Polímeros/efectos adversos , Radiografía , Factores de Riesgo , Sinovitis/etiología , Fracturas de la Tibia/cirugía , Factores de TiempoAsunto(s)
Implantes Absorbibles/efectos adversos , Tornillos Óseos/efectos adversos , Reacción a Cuerpo Extraño/etiología , Ácido Láctico/efectos adversos , Polímeros/efectos adversos , Complicaciones Posoperatorias/etiología , Adulto , Traumatismos del Tobillo/cirugía , Femenino , Fracturas Óseas/cirugía , Humanos , Poliésteres , Factores de TiempoRESUMEN
The use of absorbable internal fracture fixation devices instead of conventional metallic ones abolishes the need for subsequent implant removal procedures. Absorbable fracture fixation devices have been increasingly used during the past decade. Approximately 150,000 patients in many countries have already been treated with such implants. The vast majority of the clinically used biodegradable devices are made of polyglycolide (PGA) or polylactide (PLA). The polylactide osteosynthesis devices in clinical use today usually consist of polylevolactide (PLLA). During the past decade, the assortment of implants for fracture fixation purposes has become broader and now includes many different kind of devices.
RESUMEN
BACKGROUND: The role of plate fixation in the management of fresh displaced midclavicular fractures is unsettled. The objective of this study was to evaluate the drawbacks and pitfalls of this treatment method. METHODS: We analyzed the complications encountered in 103 consecutive adult patients with severely displaced fresh fractures of the middle third of the clavicle who were treated by open reduction and internal fixation using AO/ASIF plates. These 103 patients accounted for 9.5% of the 1,081 patients with fresh midclavicular fractures seen between 1989 and 1995. The mean age of the 103 patients was 33.4 years (range, 19-62 years). RESULTS: Seventy-nine patients had an uneventful recovery, whereas 24 (23%) suffered one or several complications. The major complications included deep infection, plate breakage, nonunion, and refracture after plate removal. The most common of the minor complications was plate loosening resulting in malunion. The infection rate was 7.8%. A total of 14 reoperations were performed because of the complications. Permanent nonunion ensued in two patients. A severely comminuted fracture (relative risk of failure, 5.15) as well as a state of alcohol intoxication on admission (relative risk of failure, 3.12) were identified as markers of increased complication risk. CONCLUSIONS: Patient noncompliance with the postoperative regimen could be suspected to have been a major cause of the failures. The high complication rate supports a reserved attitude toward plate fixation of fresh midclavicular fractures. The method should be reserved for patients who have trustworthy personal motives for quick pain relief and functional recovery.
Asunto(s)
Placas Óseas , Clavícula/lesiones , Fracturas Óseas/cirugía , Complicaciones Posoperatorias/etiología , Adulto , Intoxicación Alcohólica/complicaciones , Femenino , Fijación Interna de Fracturas , Fracturas Óseas/complicaciones , Fracturas Óseas/diagnóstico por imagen , Fracturas Conminutas/diagnóstico por imagen , Fracturas Conminutas/cirugía , Fracturas Mal Unidas/diagnóstico por imagen , Fracturas Mal Unidas/etiología , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/diagnóstico por imagen , Radiografía , Reoperación , Insuficiencia del Tratamiento , Negativa del Paciente al TratamientoRESUMEN
The degradation of a bioresorbable poly(L-lactide) osteosynthesis plug after fixation of a transferred coracoid bone block using the Bristow-Latarjet procedure was examined by means of magnetic resonance (MR) imaging. There were 15 patients with a mean follow-up time of 38 months (range 34-42 months). The gross geometry of the biomaterial plug remained unaltered on the MR images. The bone marrow signal reached the implant surfaces in all cases, and no signs of liquid phase around the implant could be discerned. The implants themselves were visible as homogeneous low signal intensity (SI) black linear structures when compared to the surrounding bone, which had a much higher SI. The mean implant SI was 18.2 (s.d. +/- 6.6), that of the scapular bone 48.9 (s.d. +/- 14.3) and that of the background 4.3 (s.d. +/- 1.5). The SI of a newly manufactured intact implant was 5.7. Serial plain radiographs showed no decreased bone density or focal osteolytic lesions around the poly(L-lactide) expansion plug. The implant channel was discernible on most of the radiographs and a sclerotic rim was detected to outline the implant profile in some of the projections of plain radiographs at each follow-up examination. Computer tomography scans on five patients 3 years postoperatively also revealed a discernible implant channel outlined with a sclerotic rim. The radiographic appearance of the radiolucent implant channel did not change over the follow-up period. Summarizing the present findings, MR imaging seems to be able to visualize poly(L-lactide) implants within the bone. Actually, at present it is the only method available to study the degradation process of implants made of this polymer in humans. No signs of degradation of or of an osteolytic foreign-body reaction to poly(L-lactide) at the host tissue-implant interface could be observed within the follow-up times of this study.
Asunto(s)
Materiales Biocompatibles/metabolismo , Sustitutos de Huesos/metabolismo , Imagen por Resonancia Magnética , Poliésteres/metabolismo , Prótesis e Implantes , Luxación del Hombro/cirugía , Absorción , Adolescente , Adulto , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Luxación del Hombro/diagnóstico por imagen , Luxación del Hombro/patología , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
OBJECTIVE: To scrutinize the fracture patterns of femoral shaft fractures caused by low-energy injury mechanism and to delineate the problems associated with the treatment of these fractures. MATERIALS AND METHODS: Of a total of 192 consecutive skeletally mature patients with 201 acute fresh femoral shaft fractures admitted during a 10-year period (1985-1994), 50 patients had a fracture caused by low-energy trauma. The fractures were classified in terms of their configuration, site, degree of comminution, and soft-tissue injury. The previous fractures, chronic illnesses, and continuous medications of the patients as well as the injury mechanisms and concomitant injuries were registered. All general and local complications and their consequences were recorded. Forty patients could be followed until the bony union of the fracture was achieved, the mean follow-up time being 14 months. RESULTS: The incidence of these injuries was 2.5 per 100,000 person-years. There were 32 women and 18 men. The mean age of the patients was 65 years (range, 17-92 years). Thirteen patients were younger than 60 years of age. Thirty-two (64%) had at least one local or general factor weakening the mechanical strength of the bone that predisposed them to a fracture. Thirty-two patients sustained a fracture of the left femur (p < 0.05). All fractures were closed. None of the patients had significant concomitant injuries. In 33 cases, the site of the fracture was in the middle third of the femur. The fracture configuration was spiral in 29, transverse in 10, oblique-transverse in 7, and oblique in 4 cases. Postoperative complications, including delayed union, nonunion, and malunion, occurred with 29 patients. Eighteen reoperations among 12 patients were performed because of these complications. CONCLUSIONS: Femoral shaft fractures caused by low-energy violence occur mainly in patients suffering from a chronic disease or a condition causing osteopenia of the femur. The most common fracture pattern was a spiral one in the middle third of the femoral shaft. Despite the low-energy violence, the treatment of these fractures is not devoid of complications. The treatment of these seemingly simple fractures requires careful planning and meticulous operative technique.
Asunto(s)
Fracturas del Fémur/patología , Fracturas Cerradas/patología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Fracturas del Fémur/etiología , Fracturas del Fémur/cirugía , Curación de Fractura , Fracturas Cerradas/etiología , Fracturas Cerradas/cirugía , Humanos , Masculino , Persona de Mediana Edad , Factores de RiesgoRESUMEN
We analysed the complications encountered in 102 consecutive patients who had posterolateral lumbosacral fusion performed with transpedicular screw and rod fixation for non-traumatic disorders after a minimum of two years. Of these, 40 had spondylolysis and spondylolisthesis, 42 a degenerative disorder, 14 instability after previous laminectomy and decompression, and six pain after nonunion of previous attempts at spinal fusion without internal fixation. There were 75 multilevel and 27 single-level fusions. There were 76 individual complications in 48 patients, and none in the other 54. The complications seen were screw misplacement, coupling failure of the device, wound infection, nonunion, permanent neural injury, and loosening, bending and breakage of screws. Screw breakage or loosening was more common in patients with multilevel fusions (p < 0.001). Screws of 5 mm diameter should not be used for sacral fixation. Forty-six patients had at least one further operation for one or several complications, including 20 fusion procedures for nonunion. The high incidence of complications is a disadvantage of this technically-demanding method.
Asunto(s)
Vértebras Lumbares/cirugía , Complicaciones Posoperatorias/epidemiología , Sacro/cirugía , Fusión Vertebral/efectos adversos , Adolescente , Adulto , Anciano , Distribución de Chi-Cuadrado , Falla de Equipo/estadística & datos numéricos , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Fijadores Internos/efectos adversos , Fijadores Internos/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía , Reoperación/estadística & datos numéricos , Enfermedades de la Columna Vertebral/complicaciones , Enfermedades de la Columna Vertebral/diagnóstico , Enfermedades de la Columna Vertebral/cirugía , Fusión Vertebral/instrumentación , Fusión Vertebral/estadística & datos numéricosRESUMEN
Twenty consecutive patients with 21 surgically repaired Achilles tendon ruptures were imaged with a 0.1-T magnet at 3 and 6 weeks, and at 3 and 6 months after surgery. Clinical follow-up examinations and functional tests were performed at the time of scanning. An intratendinous area of high-intensity signal was observed in 19 of the 21 surgically repaired Achilles tendons at 3 months after surgery on proton density- and T2-weighted images. The three patients with the largest lesions had clinically poor outcomes at 3 months, whereas those with smaller intratendinous lesions had normal recoveries. Furthermore, patients with an abnormal walk at 3 months (N = 5) had statistically larger intratendinous lesions than patients who could walk normally. In all patients the cross-sectional area of the rejoined Achilles tendon showed the largest increase after cast removal (between 6 weeks and 3 months after surgery). In all cases the largest tendon area was measured at 3 months after surgery. Magnetic resonance imaging provides a precise valuable tool to evaluate the postsurgical internal structure of the surgically repaired Achilles tendon.
Asunto(s)
Tendón Calcáneo/lesiones , Tendón Calcáneo/cirugía , Cicatrización de Heridas , Tendón Calcáneo/patología , Adulto , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Rotura/cirugía , Traumatismos de los Tendones/patología , Traumatismos de los Tendones/cirugía , Factores de TiempoRESUMEN
Nine adolescent patients with a femoral fracture involving the physeal plate were treated by using self-reinforced absorbable polyglycolide (SR-PGA) and poly-L-lactide (SR-PLLA) screws with a follow-up for an average of 2 years and 2 months. During the follow-up all but one of the femurs became skeletally mature. In two of nine patients a clinically significant growth disturbance occurred. The average length difference of the femurs was -5 mm (ranging from +8 mm(-)-41 mm). One valgus deformity was noted. In four patients a lengthening and in four patients a shortening of the operated femur were registered at the end of follow-up. Open reduction and fixation with absorbable screws seem to be suitable for the fixation of distal femoral fractures in adolescents.
Asunto(s)
Materiales Biocompatibles , Tornillos Óseos , Fracturas del Fémur/cirugía , Fijación Interna de Fracturas/instrumentación , Poliésteres , Ácido Poliglicólico , Adolescente , Materiales Biocompatibles/metabolismo , Materiales Biocompatibles/uso terapéutico , Biodegradación Ambiental , Epífisis/lesiones , Epífisis/cirugía , Femenino , Fracturas del Fémur/diagnóstico por imagen , Estudios de Seguimiento , Fijación Interna de Fracturas/métodos , Curación de Fractura/fisiología , Humanos , Masculino , Pronóstico , Estudios Prospectivos , RadiografíaRESUMEN
OBJECTIVE: To assess the feasibility of magnetic resonance (MR) imaging in the postoperative follow-up after internal fracture fixation using biodegradable polylevolactide (PLLA) plugs and to investigate the MR characteristics of these devices. STUDY DESIGN AND METHODS: MR findings in ten patients with displaced malleolar fractures treated by internal fixation using absorbable PLLA plugs were evaluated after three different postoperative periods. The average postoperative follow-up time was thirty months for four patients, forty-two months for another four patients, and fifty-one months for the remaining two patients. RESULTS: On T1-weighted coronal images, the geometry of the PLLA plug was clearly visible in all cases, without signs of fatigue failure or absorption. The host-to-tissue area between the deployed two fins of the plug showed higher signal intensity than the surrounding cancellous bone on fat-saturated proton density (PD) and turbo inversion recovery (tIR) images. This area had signal intensity similar to articular cartilage on T1-weighted coronal images. In none of the cases could any fluid accumulation be seen around the plug. In all ten cases, a thin rim with signal intensity similar to the area between the deployed fins was detected around the PLLA plug on fat-saturated axial PD images. On fat-saturated T2 and tIR sequences, this rim was less clearly detectable in all cases. No differences in the signal intensity or geometry of the PLLA plug on the MR images emerged between the three patient groups with mean follow-ups of thirty, forty-two, and fifty-one months. No artifacts produced by the implants were seen on any of the MR images. A biopsy specimen obtained at a reoperation necessary seventeen months postoperatively showed no signs of degradation of the PLLA plug. CONCLUSIONS: MR imaging can visualize PLLA implants within bone. It also shows, without artifacts, the tissue interaction between the artificial biodegradable material and bone tissue in humans.
Asunto(s)
Traumatismos del Tobillo/cirugía , Materiales Biocompatibles , Fijación Interna de Fracturas/instrumentación , Imagen por Resonancia Magnética , Poliésteres , Fracturas de la Tibia/cirugía , Absorción , Adolescente , Adulto , Anciano , Traumatismos del Tobillo/patología , Artefactos , Biodegradación Ambiental , Clavos Ortopédicos , Cartílago Articular/patología , Diseño de Equipo , Falla de Equipo , Estudios de Evaluación como Asunto , Estudios de Factibilidad , Femenino , Estudios de Seguimiento , Curación de Fractura , Humanos , Aumento de la Imagen , Masculino , Persona de Mediana Edad , Propiedades de Superficie , Fracturas de la Tibia/patologíaRESUMEN
OBJECTIVE: Assess the workload caused by elective routine removals of internal fracture fixation devices in a large university orthopedic and trauma unit when no premeditated departmental removal policy existed. MATERIALS AND METHODS: Data on all operations performed during a 7-year period were retrieved. Routine removals of internal fracture fixation implants were analyzed for demographic data and clinical details. Patients requiring additional procedures to manage the fracture besides simple hardware removal were excluded. Nationwide data were included for comparison. RESULTS: A total of 5,095 routine implant removal operations were performed after uneventful fracture union. The mean age of the patients was 42 years. The five most common fracture types were fractures of the ankle, the proximal femur, the tibial shaft, the femoral shaft, and the thoracolumbar spine. In 63% of the procedures, a medium-size or large implant was removed. The mean operation time was 37 minutes. The removals accounted for 29% of all elective operations and for 15% of all operations at the department. The corresponding nationwide figure was 6.3% of all orthopedic operations, the number of implant removals in the whole country being 90 operations per 100,000 person-years. CONCLUSIONS: Without a strict departmental removal policy, a remarkable portion of the resources allocated for elective orthopedic operations was spent on routine hardware removal procedures. A more rational and selective attitude toward implant removals is desirable. Further research on the disadvantages of retained hardware and the complications of implant removals is required.
Asunto(s)
Fijación Interna de Fracturas/instrumentación , Fijación Interna de Fracturas/estadística & datos numéricos , Centros Traumatológicos , Adulto , Finlandia , Fijación Interna de Fracturas/economía , Fracturas Óseas/cirugía , Recursos en Salud/estadística & datos numéricos , Humanos , Metales , Reoperación , Centros Traumatológicos/estadística & datos numéricosRESUMEN
Absorbable polyester pins and screws for the internal fixation of small fragment fractures have been commercially available for several years. The main advantage of these devices is that no implant removal procedures are required, which could result in financial savings. The current cost analysis, which included costs of medical care plus costs of lost time from work, was based on 994 fracture patients treated with absorbable internal fixation devices and 1173 patients operated on using conventional metallic devices. The fracture types studied were uni- and trimalleolar fractures of the ankle, fractures of the olecranon, and metacarpal fractures. When the costs for an implant removal procedure after metallic fixation were included, the average cost saved per patient by using absorbable implants varied from $410 in fractures of the olecranon to $903 in unimalleolar fractures. However, hardware removals often are optional. According to the results of this cost analysis, the break even point is attained at a removal rate of 19% for metacarpal fractures, 21% for unimalleolar fractures, 46% for fractures of the olecranon, and 54% for trimalleolar fractures. Only at a higher removal rate would the use of absorbable devices, with their current prices, be a financially more favorable alternative than the use of metallic ones.
Asunto(s)
Traumatismos del Tobillo/cirugía , Fijación Interna de Fracturas/economía , Fracturas Óseas/cirugía , Fijadores Internos/economía , Metacarpo/lesiones , Adolescente , Adulto , Anciano , Traumatismos del Tobillo/economía , Clavos Ortopédicos , Tornillos Óseos , Costos y Análisis de Costo , Fracturas Óseas/economía , Humanos , Metacarpo/cirugía , Persona de Mediana EdadRESUMEN
Totally absorbable internal fracture fixation devices were introduced clinically in the treatment of fractures and osteotomies of the extremities at our department in 1984. A total of 2,500 patients were managed using bone or ligament fixation devices made of self-reinforced (matrix and fibers of same polymer) absorbable alpha-hydroxy polyesters between November 5, 1984, and January 12, 1994. The devices used included cylindrical rods or pins, screws, tacks, plugs, and wires. The most common indication for the use of absorbable implants was displaced malleolar fracture of the ankle. Transphyseal fixation with small-diameter polyglycolide pins was used in children. The postoperative clinical course was uneventful in over 90% of the patients. The complications included bacterial wound infection in 3.6% and failure of fixation in 3.7%. In one-fifth of these cases, however, reoperation was not necessary. The occurrence of noninfectious foreign-body reactions 2 to 3 months postoperatively has been observed in 2.3% of the patients operated in the last years with polyglcolide implants but in none of the patients with polylactide implants. This inflammatory tissue response often required aspiration with a needle or small incision but did not influence the ultimate functional or radiologic result of treatment. Owing to the biodegradability of these internal fixation devices, over 1,000 implant removal procedures were avoided during the 9-year period under review, allowing medical personnel at these facilities to focus on other procedures. Avoidance of removal procedures results in financial benefits and psychological advantages. The benefits of absorbable implants for war surgery are the same as for civilian life. Absorbable implants can also be used in open fractures and infection operations.