RESUMEN
Clinical results of the initial cemented and cementless series of 373 New Jersey Low Contact Stress total knee replacements in 282 patients surviving at least 10 years were analyzed using a strict knee scoring scale. The study showed excellent, good, fair, or poor results in 68.1%, 29.8%, 2.1%, or 0% of primary posterior cruciate-retaining meniscal bearing knee replacements, 46.7%, 53.3%, 0%, or 0% results in primary cemented rotating platform knee replacements, and 68.1%, 29.8%, 2.1%, or 0% results in primary cementless rotating platform knee replacements, respectively. Radiographic evaluation at minimum 10-year followup showed stable fixation of all components, no gross migration but significant osteolysis requiring bearing exchange and bone grafting in three cementless rotating platform knee replacements (1.8%) in three patients who underwent previous surgeries at an average of 10.2 years from the index surgery. Survivorship of the patients who underwent primary cementless posterior cruciate-retaining meniscal bearing knee replacements with an end point of revision for any mechanical reason was 97.4% at 10 years and 83% at 16 years; using an end point of a poor clinical knee score the survivorship was 98.9% at 10 years and at 16 years. Survivorship of the patients who underwent primary cemented rotating platform knee replacements with end points of revision for any mechanical reason or a poor clinical knee score was 97.7% at 10 years and at 20 years. Survivorship of the patients who underwent cementless rotating platform knee replacements with end points of revision for any mechanical reason or a poor clinical knee score was 98.3% at 10 years and at 18 years.
Asunto(s)
Prótesis de la Rodilla , Adulto , Anciano , Anciano de 80 o más Años , Artritis Reumatoide/cirugía , Artroplastia de Reemplazo de Rodilla , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Osteoartritis de la Rodilla/cirugía , Diseño de Prótesis , Resultado del TratamientoRESUMEN
In vivo weight-bearing studies utilizing dynamic video fluoroscopy have been shown to offer an accurate and reproducible method for determining the kinematics of a joint. The purpose of this study was to evaluate translational and rotational motions of the distal tibia relative to the talus in the sagittal and frontal planes. Ten subjects, each having a normal ankle and a total ankle arthroplasty on the opposite side (Buechel-Pappas Total Ankle, Endotec, South Orange, NJ), were studied under in vivo, weight-bearing conditions using video fluoroscopy. All ten subjects were judged to have a successful arthroplasty without demonstrable pain or ligament instability. Under weight-bearing conditions, each subject performed successive motions moving from maximum dorsiflexion to plantarflexion. At maximum dorsiflexion, both the normal and implanted ankles had similar sagittal midline talar contact positions but with plantar flexion, implanted ankles had increased posterior talar contact. Contact points on the distal tibia revealed that the lateral surface contacted at the midline or posterior throughout range-of-motion with minimal translation. The medial distal tibia contacted the talus posterior on plantarflexion and often moved anteriorly with dorsiflexion. This translation described relative external rotation of the distal tibia on plantar flexion and internal rotation on dorsiflexion. The measured distances were larger for the implanted ankles with higher variability. The average range-of-motion was 37.4 degrees for normal ankles and 32.3 degrees for implanted ankles. This study defines the normal kinematic rotational and translational motions of the ankle joint by accurately describing the three dimensional joint orientations. The implanted ankles experienced rotational and translational motions but had contacts more posterior, possibly related to surgical technique or alterations of ligamentous tension.
Asunto(s)
Articulación del Tobillo/fisiología , Fluoroscopía , Rango del Movimiento Articular/fisiología , Articulación del Tobillo/diagnóstico por imagen , Articulación del Tobillo/cirugía , Artralgia/prevención & control , Artroplastia de Reemplazo , Simulación por Computador , Humanos , Procesamiento de Imagen Asistido por Computador , Inestabilidad de la Articulación/prevención & control , Ligamentos Articulares/fisiología , Movimiento , Reproducibilidad de los Resultados , Rotación , Propiedades de Superficie , Astrágalo/fisiología , Tibia/fisiología , Grabación de Cinta de Video , Soporte de Peso/fisiologíaRESUMEN
Wear debris of polyethylene, polymethylmethacrylate, and metal have been recognized to be associated with foreign body reactions, osteolysis, and aseptic prosthetic loosening after joint replacement arthroplasty. Further, foreign body reaction due to the presence of extensive wear debris can cause aggressive granulomatous lesions and pathologic fracture. To our knowledge, there has been no previous report of pathologic fracture of the femur due to an agressive pseudotumor. This report describes a case of pathologic supracondylar fracture of the femur 6 years and 5 months after cementless total knee replacement arthroplasty. The fracture occurred through an aggressive expanding soft tissue mass that was a tumorlike lesion secondary to polyethylene wear debris. The lesion was associated with massive osteolysis around the femoral component of the total knee prosthesis.
Asunto(s)
Artroplastia de Reemplazo de Rodilla/efectos adversos , Fracturas Espontáneas/patología , Granuloma de Células Plasmáticas/patología , Materiales Biocompatibles/efectos adversos , Fémur/lesiones , Fémur/patología , Fracturas Espontáneas/diagnóstico por imagen , Fracturas Espontáneas/etiología , Granuloma de Células Plasmáticas/complicaciones , Granuloma de Células Plasmáticas/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Polietilenos/efectos adversos , Polimetil Metacrilato/efectos adversos , Radiografía , ReoperaciónRESUMEN
We discovered a unique case of complete cartilaginous duplication of the rib cage in a cadaver, never previously described in the literature. A retrospective review of the patient's medical records revealed an antecedent history of progressive tobacco-related emphysema leading to death from end stage respiratory failure. Prior imaging studies consisting of plain radiographs and computed tomograms of the chest had failed to show several underlying cartilaginous duplications of the rib cage. The clinical significance and the potential contribution of this entity to this patient's clinical course remains unanswered.
Asunto(s)
Cartílago/anomalías , Costillas/anomalías , Anciano , Anciano de 80 o más Años , Cadáver , Cartílago/embriología , Humanos , Masculino , Costillas/embriologíaRESUMEN
Wear is a major late complication of total joint arthroplasty, particularly for younger, active patients. Many patients could produce > 40 million motion cycles after joint replacement. Based on current experience and testing, typical joint prostheses are likely to wear out, and need revision in such patients. One problem is degradation of the metal (counterface) surface. A harder, more abrasion resistant, counterface surface is needed. This study evaluated the long-term wear of the titanium nitride ceramic film against ultra high molecular weight polyethylene. In this test, 4 47-mm femoral cups with a polished 8-micron-thick titanium nitride coating were run against 4-mm-thick metal-backed polyethylene bearings machined from GUR415 extruded rod in water at 37 degrees C at 5 Hz and a 2200-N fluctuating load. Wear of the counterface and bearing were extremely low. The average maximum reduction in thickness of the polyethylene was < 0.02 mm, and < 2 microns in the ceramic film. The average polyethylene wear rate was only approximately 2% of that found in a similar test using 32-mm cobalt chromium femoral heads. The titanium nitride-polyethylene couple has great potential as a lifetime bearing combination.
Asunto(s)
Aleaciones , Cerámica , Prótesis de Cadera , Titanio , Cabeza Femoral , Humanos , Polietilenos , Diseño de PrótesisAsunto(s)
Prótesis de la Rodilla/métodos , Adulto , Anciano , Anciano de 80 o más Años , Artritis/cirugía , Artritis Reumatoide/cirugía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Osteoartritis/cirugía , Diseño de Prótesis , Reoperación , Resultado del TratamientoRESUMEN
Ten cases of major osteolysis were identified in patients with hemispherical cobalt chrome acetabular components of cementless resurfacing total hip prostheses at follow-up examinations ranging from two to five years. All components were porous coated with cobalt chrome spheres and were stabilized initially with screws. Five patients were women and five were men, with ages ranging from 20 to 59 years. The radiolucent cystic lesions with peripheral rims of reactive bone formation appeared one to five years after the operation. They measured from 1.5 to 6 cm in the largest diameter and were most often found adjacent to the screws used to secure the acetabular components to the skeleton. On the radiographs, none of the components appeared to be loose. Three patients had revision surgery. In two of the three cases, the implants were found to be firmly fixed. There was no clinical or bacteriologic evidence of infection. The polyethylene articulating surface showed signs of wear in all three cases and in one of the three it dislocated from the metal shell. Granulation tissue was found in the regions of osteolysis, and the diseased tissue contained numerous macrophages and giant cells. Lymphocytes and plasma cells were rare. Numerous small particles of phagocytosed polyethylene and metal in the cells were noted in two cases, whereas only polyethylene was found in the third.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Acetábulo/cirugía , Aleaciones de Cromo , Prótesis de Cadera , Osteólisis/diagnóstico por imagen , Acetábulo/diagnóstico por imagen , Adulto , Corrosión , Femenino , Reacción a Cuerpo Extraño/patología , Humanos , Masculino , Persona de Mediana Edad , Osteólisis/patología , Polietilenos , Radiografía , ReoperaciónRESUMEN
OBJECTIVE: To compare quantitatively the in vivo expression of collagenase messenger RNA (mRNA) and stromelysin mRNA in the joint tissues of human osteoarthritis (OA) and rheumatoid arthritis (RA) patients and in two animal models of acute inflammatory arthritis. METHODS: In vivo levels of metalloproteinase mRNA and protein were determined by quantitative Northern hybridization and by enzyme-linked immunosorbent assay, respectively. RESULTS: In synovium, mean levels of collagenase mRNA were similar to those of stromelysin mRNA; however, in cartilage, mean levels of collagenase mRNA were significantly lower. The ratios of collagenase mRNA to stromelysin mRNA levels in RA and OA cartilage reflected similar ratios of collagenase protein to stromelysin protein levels in synovial fluid. CONCLUSION: The regulation of collagenase mRNA expression in cartilage is distinct from that of stromelysin, suggesting distinct roles for these two metallo-proteinases in normal and abnormal physiologic functioning of cartilage.
Asunto(s)
Cartílago Articular/enzimología , Colagenasas/genética , ARN Mensajero/análisis , Membrana Sinovial/enzimología , Adulto , Anciano , Animales , Artritis Reumatoide/metabolismo , Northern Blotting , Cartílago Articular/química , Células Cultivadas , Medios de Cultivo Condicionados/farmacología , Modelos Animales de Enfermedad , Perros , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Hibridación in Situ , Interleucina-1/farmacología , Masculino , Metaloproteinasa 3 de la Matriz , Metaloendopeptidasas/genética , Persona de Mediana Edad , Monocitos , Osteoartritis/metabolismo , Conejos , Líquido Sinovial/química , Membrana Sinovial/químicaRESUMEN
A porous-coated, cementless, congruent-contact, meniscal-bearing total ankle replacement with a centrally placed trochlear groove and a cylindrical articulating axis representing the lateral talar curvature was developed and used clinically over a 10-year period. An initial clinical series of 40 ankle replacements involved the use of cobalt-chromium-molybdenum tibial and talar components with sintered-bead porous coating of 275-mum pore size and a shallow-sulcus trochlear groove with a central fixation fin for the talar onlay component. The congruent meniscal bearing, made of ultrahigh molecular-weight polyethylene (UHMWPe), was flat superiorly and matched the shallow-sulcus and cylindrical geometry inferiorly. Two bearings in two patients subluxed laterally and required revision within 2 years. The overall cumulative survival at the 10-year interval for this group using revision as an end point was 94.75%. The clinical results, using a strict ankle evaluation scoring scale, demonstrated 85% overall good to excellent results. Three patients required further treatment for intermalleolar exostoses, one patient required a debridement for infection, two ankles had medially subluxed bearings, eight ankles developed talar component subsidence, and two patients suffered from chronic reflex-sympathetic dystrophy. A second clinical series of 14 ankle replacements involved the use of polished titanium-nitride-coated titanium-6 aluminum-4 vanadium tibial and talar components with sintered-bead porous coating of 350-mum pore size and a deep-sulcus trochlear groove with two lateral fixation fins for the talar onlay component. The bearing element was similar to the initial series except that it had a deeper engagement in the trochlear groove to prevent subluxation.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Articulación del Tobillo/cirugía , Prótesis Articulares/instrumentación , Adulto , Anciano , Anciano de 80 o más Años , Traumatismos del Tobillo/cirugía , Artritis Reumatoide/epidemiología , Artritis Reumatoide/cirugía , Fenómenos Biomecánicos , Estudios de Evaluación como Asunto , Humanos , Persona de Mediana Edad , Osteoartritis/epidemiología , Osteoartritis/cirugía , Diseño de Prótesis , Falla de Prótesis , Estrés Mecánico , Análisis de SupervivenciaRESUMEN
Significant wear-through and dissociation failures of metal-backed, point and line contact patellar replacements are associated with excessive contact stresses on the polyethylene-bearing surfaces. Analytical mathematical contact-stress analysis was used to evaluate various patellar component geometries under loading conditions consistent with walking, stair descent, and deep knee bends, respectively. Typical point- and line-contact patellar-surface geometries exceeded the manufacturer's recommended maximum permissible compressive stress level of 10 MPa by a factor greater than three, which also exceeds the yield stress of ultra-high, molecular-weight polyethylene. A metal-backed, rotating-bearing, area contact geometry patellar replacement maintained safe contact stress levels at less than half of the maximum permissible compressive stress level. These contact stress analyses predict early fatigue failure of all-polyethylene or metal-backed, point- and line-contact patellar replacements, while predicting long-term survival of area-contact, rotating-patellar replacements. Clinical evaluation of these various implants support the conclusions of these analyses. Contact stress analysis should precede any clinical use of patellar implants to avoid predictable failure mechanisms.
Asunto(s)
Prótesis de la Rodilla , Rótula , Estrés Mecánico , Fenómenos Biomecánicos , Humanos , Metales , Polietilenos , Falla de PrótesisRESUMEN
A technique for restoring the moment arm to improve quadriceps leverage after patellectomy has been developed and used in patients treated with total knee arthroplasty. Essentials of the technique involve use of a 2.5-cm diameter by 1-cm thick bone graft sewn into the previous anatomical position of the patella, using a subsynovial pouch for stabilization. Clinically, seven knees in six patients were treated with patellar tendon bone grafting during total knee arthroplasty. The final outcome of these patients was evaluated from 24 to 125 months (mean, 75.4 months). Good to excellent results were demonstrated in six of seven knees (85.7%) with sufficient extension power for normal gait in most cases. Failure to achieve painless, active extension was seen in one patient following revision knee arthroplasty complicated by chronic reflex sympathetic dystrophy of the knee. Patellar tendon bone grafting improves quadriceps leverage in previously patellectomized knees and is useful in restoring extensor function in such patients having primary or revision knee arthroplasty.
Asunto(s)
Trasplante Óseo/métodos , Prótesis de la Rodilla , Rótula/cirugía , Tendones/cirugía , Adulto , Anciano , Artritis/cirugía , Trasplante Óseo/efectos adversos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , ReoperaciónRESUMEN
From 1977 through 1987, 21 meniscal-bearing unicompartmental knee arthroplasties (UKAs) were performed on 20 patients in preference to a distal femoral or proximal tibial osteotomy for unicompartmental knee arthritis. Preoperative diagnoses were osteoarthritis (14 cases), posttraumatic arthritis (5 cases), and rheumatoid arthritis (1 case). Eighteen UKAs (7 lateral, 11 medial) were followed for 24 to 132 months (mean, 34). Using the New Jersey Orthopedic Hospital Knee Scoring Scale, good to excellent clinical results were found in 16 (89%) of the UKAs followed for at least two years. These scores represent significant improvement over preoperative evaluation, (paired t test, P less than or equal to .05). No statistical difference was noted in postoperative results between the lateral or medial arthroplasties (Student's t test, P less than or equal to .05).
Asunto(s)
Prótesis de la Rodilla , Osteoartritis/cirugía , Adulto , Anciano , Femenino , Humanos , Articulación de la Rodilla/fisiología , Masculino , Meniscos Tibiales , Persona de Mediana Edad , Diseño de Prótesis , Rango del Movimiento Articular , Estudios RetrospectivosRESUMEN
Long-term investigational device exemption (IDE) clinical trial evaluation, as currently monitored by the Food and Drug Administration (FDA) regulatory process, is time-consuming, burdensome, and extremely costly to the product developers and ultimately to the consumer. Thus, almost all devices introduced in the past decade have not been clinically tested; they have been introduced under a "510k" grandfather provision that does not address the safety and efficacy of the product. As a result, joint replacement devices have been sold and used with serious failure consequences for the consumer. When 10-year survivorship studies are available for specific joints that demonstrate strong evidence of favorable clinical performance with suitable supporting analysis, they can be used as a standard for comparison with newer, similar designs. Additionally, contact stress analysis of the bearing surfaces of these joint replacements can be used to determine their long-term wear characteristics under normal loading conditions and compared to retrieved devices used for 10 years or more. Devices that demonstrate a 90% survivorship over a 10-year interval and have low enough contact stresses to minimize wear failure during the same period can be used as "standard designs" to which newer designs should be compared. Using this methodology, the developers of any new device should cite the standard design that they have improved on and document an improvement in early (1 to 3 years) survivorship studies with a contact stress analysis demonstrating bearing contact stresses equal to or lower than the standard design. Any device that fails more often or wears out faster than a standard design should not be released until design modifications have proved it superior or equal to the standard designs.
Asunto(s)
Prótesis Articulares/normas , Estrés Mecánico , Fenómenos Biomecánicos , Diseño de Equipo , Falla de Equipo , Seguridad de Equipos , HumanosRESUMEN
A comprehensive, interchangeable, low-contact-stress, mobile-bearing knee prosthesis system was developed and used over a 12-year period with both cemented and cementless fixation. Individual components of the system included a bicruciate-retaining meniscal bearing, a posterior cruciate-retaining meniscal bearing, and a cruciate-sacrificing, rotating-platform tibial component mated to the same femoral and rotating patellar components. Survivorship analysis of each implant type was performed to identify specific failure modes and trends for long-term survival of the implants in a wide variety of primary knee arthroplasties. Clinically, there were 46 prostheses of the bicruciate type followed for up to 12 years, 57 prostheses of the posterior-cruciate type followed for up to six years, and 108 prostheses of the rotating-platform type followed for up to ten years. All knees in this study had rotating-bearing patellar prostheses. Cumulative survivorship analysis using an end point of implant revision or a poor knee score revealed a small early failure rate of each implant in the first three years, associated with technical positioning or undersizing errors. This study indicates a predictable long-term survival of both cruciate-retaining and cruciate-sacrificing mobile-bearing knee prostheses as well as rotating-bearing patellar prostheses when used in primary knee arthroplasties that minimized technical errors of insertion.
Asunto(s)
Ligamento Cruzado Anterior , Prótesis de la Rodilla , Ligamento Cruzado Posterior , Análisis de Supervivencia , Adulto , Anciano , Anciano de 80 o más Años , Ligamento Cruzado Anterior/cirugía , Femenino , Humanos , Tablas de Vida , Masculino , Meniscos Tibiales/cirugía , Persona de Mediana Edad , Ligamento Cruzado Posterior/cirugía , Diseño de PrótesisRESUMEN
An approach to mild, moderate, and severe fixed valgus deformities of the knee is described. The sequential approach to soft-tissue releases in the fixed valgus knee allows the surgeon to regain a neutral alignment in valgus deformities of up to 90 degrees. An additional benefit of the approach is spontaneous correction of fixed external tibial rotation deformities. Using this approach, early and late stability allows the use of unconstrained knee implants, including those with mobile-bearing elements.