RESUMEN
BACKGROUND AND PURPOSE: Due to the relative lack of reports on the medium- to long-term clinical and radiographic results of modular femoral cementless revision, we conducted this study to evaluate the medium- to long-term results of uncemented femoral stem revisions using the modular MRP-TITAN stem with distal diaphyseal fixation in a consecutive patient series. PATIENTS AND METHODS: We retrospectively analyzed 163 femoral stem revisions performed between 1993 and 2001 with a mean follow-up of 10 (5-16) years. Clinical assessment included the Harris hip score (HHS) with reference to comorbidities and femoral defect sizes classified by Charnley and Paprosky. Intraoperative and postoperative complications were analyzed and the failure rate of the MRP stem for any reason was examined. RESULTS: Mean HHS improved up to the last follow-up (37 (SD 24) vs. 79 (SD 19); p<0.001). 99 cases (61%) had extensive bone defects (Paprosky IIB-III). Radiographic evaluation showed stable stem anchorage in 151 cases (93%) at the last follow-up. 10 implants (6%) failed for various reasons. Neither a breakage of a stem nor loosening of the morse taper junction was recorded. Kaplan-Meier survival analysis revealed a 10-year survival probability of 97% (95% CI: 95-100). INTERPRETATION: This is one of the largest medium- to long-term analyses of cementless modular revision stems with distal diaphyseal anchorage. The modular MRP-TITAN was reliable, with a Kaplan-Meier survival probability of 97% at 10 years.
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Artroplastia de Reemplazo de Cadera/efectos adversos , Artroplastia de Reemplazo de Cadera/instrumentación , Prótesis de Cadera/efectos adversos , Reoperación/métodos , Adulto , Anciano , Anciano de 80 o más Años , Artroplastia de Reemplazo de Cadera/métodos , Cementación , Análisis de Falla de Equipo , Femenino , Estudios de Seguimiento , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía , Falla de Prótesis/etiología , Estudios Retrospectivos , TitanioRESUMEN
Compressive residual stresses are commonly introduced into the near-surface regions of morse taper junctions of modular hip endoprostheses to prolong fatigue life. An increasing number of publications report that contamination of shot-peened surfaces can lead to enhanced corrosion and third body wear. This study evaluates deep rolling of titanium alloy rods as a possible alternative to shot peening. Ten rods of Ti6Al7Nb alloy with a diameter of 15 mm were deep rolled with various rolling parameters. The resulting surface topography and residual contamination was analyzed using a scanning electron microscope (SEM). The near-surface residual stress states after deep rolling were characterized by means of X-ray diffraction. The roughness of the surfaces before deep rolling was about R(z) = 14 microm, and after deep rolling surface roughness values of R(z) 0.4-7.5 microm were achieved. The results of the SEM and EDAX analyses of the sample surface showed no evidence of surface contamination by particles or abrasion products caused by any process. At a pressure of 300 bar, compressive stress reached the maximum of -1150 MPa at a depth of 0.1 mm. Deep rolling thus allows a smooth and particle-free surface to be obtained and therefore shows promise as a surface treatment for mating surfaces of morse tapers in modular hip endoprostheses.
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Materiales Biocompatibles , Prótesis de Cadera , Titanio , Aleaciones , Humanos , Técnicas In Vitro , Microscopía Electrónica de Rastreo , Diseño de Prótesis , Propiedades de Superficie , Difracción de Rayos XRESUMEN
INTRODUCTION: Main reasons for the early revision of total hip arthroplasties are aseptic loosening as a result of wear debris caused by polyethylene particles, and postoperative dislocations. In revision arthroplasty of the hip metallic deposits were frequently found on femoral heads after dislocation or repositioning in total hip arthroplasties with metal back acetabular components. MATERIALS AND METHODS: In this study we examined ceramic femoral heads from alumina-on-alumina and alumina-on-polymer pairings, respectively. All the heads resulted from revision of total hip replacement with a titanium containing acetabular component and showed metallic deposit on their surface. The metallic deposit was characterized by environmental scanning electron microscopy, energy dispersive X-ray spectroscopy and laser scanning microscopy. RESULTS: The metallic deposits covered areas between 5 mm(2) and 8 cm(2) and reached a maximum height of 30 mum. They were shown to consist of titanium, and thus resulted from contact between the femoral head and the posterior part of the metal back. In case of twofold dislocated alumina-on-alumina pairings the titanium deposits showed different roughness profiles, whereas no differences were detectable for alumina-on-polymer pairings. CONCLUSION: From the obtained results it can be concluded, that titanium deposited onto a femoral head during dislocation will be abraded within the harder alumina-on-alumina bearing couple during normal gait and will subsequently be released into the body by synovial fluid. In case of a ceramic-on-polymer bearing the deposited metal seems to be more harmful. The increased surface roughness of the femoral head within the tribological pairing probably initiates damage of the polymeric acetabular inlay and increases the wear of the bearing surface through a third-body wear mechanism resulting in the release of high amounts of PE.
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Artroplastia de Reemplazo de Cadera , Cabeza Femoral/cirugía , Prótesis de Cadera , Falla de Prótesis , Adulto , Anciano , Óxido de Aluminio , Cerámica , Femenino , Humanos , Masculino , Microscopía Electrónica de Rastreo , Persona de Mediana Edad , Reoperación , Propiedades de Superficie , Factores de Tiempo , TitanioRESUMEN
INTRODUCTION: Blasting techniques using corundum to create rough surfaces are used in many different processes for the surface treatment of hip implants. Recent evidence points an association between residual particles and early loosenings in the sense of third-body wear. MATERIALS AND METHOD: The surfaces of five unused, original-packaged CLS stems and ARR-Titan supporting rings, respectively, were compared with five explanted CLS stems and ARR-Titan supporting rings. RESULTS: The surface of the ARR-Titan supporting rings was adhered to Al2O3 particles at 23.2+/-2.5% on the implants and 12.3+/-3.0% on the explants (P < 0.0001). For the CLS stem, the surface to which Al2O3 particles adhered was 16.4+/-2.2 % on the implants, whereas the surface to which Al2O3 particles adhered was 12.4+/-3.3% on the explants (P = 0.0275). DISCUSSION: The results of this study show that corundum particles can be found to cover a high percentage on rough-blasted titanium surfaces of ready-to-use devices. In contrast, this contamination is significantly less on the explants treated in an identical fashion prior to implantation.
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Óxido de Aluminio/efectos adversos , Artroplastia de Reemplazo de Cadera/instrumentación , Materiales Biocompatibles/efectos adversos , Prótesis de Cadera , Falla de Prótesis , Materiales Biocompatibles/uso terapéutico , Remoción de Dispositivos , Análisis de Falla de Equipo , Humanos , Diseño de Prótesis , Propiedades de Superficie , Titanio/uso terapéuticoRESUMEN
INTRODUCTION: Cementless THR is a well established, and a widely accepted optimal procedure for younger patients. The cementless Vektor-Titan stem is made of Ti6AI7Nb, has got the shape of a three-dimensional cone, and an optimal proximal anchoring property. MATERIALS AND METHODS: The aim of this prospective study was to scrutinise the outcome of 250 Vektor-Titan stems in cementless THRs with an average follow-up time of 3.0 years (Min: 1, Max: 6). The average age of the patients including 148 women and 102 men was calculated with 54.6 years (Min: 22.5, Max: 77.7). RESULTS: The score according to Merle d'Aubigné improved from preoperative 9.3 (Min: 7, Max: 13) to postoperative 17.0 (Min: 14, Max: 18). Distal cortical hypertrophy and proximal atrophy was detected in 4 cases. Single atrophy of the proximal femur was found in additional 3 cases. Progressive radiolucent lines in zone 1 and 7 according to Gruen were observed in one case. Postoperative local and general complications were seen as two subfascial hematomas, two single dislocations, two recurrent dislocations of the hip prosthesis, 6 lesions of the sciatic nerve (one persisting), two deep venous thrombosis, two pneumonias, and one lethal pulmonary embolism. A stable proximal fixation was achieved in 242 of 250 cases (96.8%). CONCLUSION: The results of this study using the Vektor-Titan stem in cementless total hip arthroplasty showed that the principle of proximal fixation was optimized. Long term follow-up studies are needed to confirm these good results.
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Artroplastia de Reemplazo de Cadera/instrumentación , Artroplastia de Reemplazo de Cadera/estadística & datos numéricos , Análisis de Falla de Equipo , Prótesis de Cadera/estadística & datos numéricos , Complicaciones Posoperatorias/epidemiología , Medición de Riesgo/métodos , Adulto , Anciano , Artroplastia de Reemplazo de Cadera/métodos , Cementación , Comorbilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/diagnóstico , Pronóstico , Falla de Prótesis , Factores de Riesgo , Resultado del TratamientoRESUMEN
Malignant fibrous histiocytoma is the most frequent sarcoma in adults. Predisposing factors for malignant fibrous histiocytoma are Paget's disease, bone infarcts, malignant disorders of the hematopoetic system, or prolonged intake of corticosteroids. Malignant fibrous histiocytoma has been described as occurring with increasing frequency after endoprosthetic therapy and has been attributed to the implants or to their alloy constituents. Malignant fibrous histiocytoma at the site of an endoprosthesis of the hip constitutes a distinct rarity. To our knowledge, only 13 cases have been described to date. In this report, we present the case of a 66-year-old woman with rheumatoid joint disease. Eight years after primary endoprosthetic surgery, loosening of the implant with severe osteolysis of the surrounding bone required replacement surgery. Histopathologic evaluation of resected tissue revealed scar and granulation tissue and Grade 3 malignant fibrous histiocytoma. The patient died 1 year after revision arthroplasty because of diffuse pulmonary and cerebral metastases. In patients with loosening of a total hip endoprosthesis in combination with severe periprosthetic osteolysis an accompanying malignancy should be in the differential diagnosis. The histopathologic examination of the resected tissue should be obligatory.
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Artritis Reumatoide/cirugía , Artroplastia de Reemplazo de Cadera/efectos adversos , Histiocitoma Fibroso Benigno/diagnóstico , Neoplasias de los Tejidos Blandos/diagnóstico , Anciano , Resultado Fatal , Femenino , Histiocitoma Fibroso Benigno/etiología , Humanos , Neoplasias de los Tejidos Blandos/etiologíaRESUMEN
INTRODUCTION: As primary total hip replacements (THRs) become more common in older patients and younger, physically active patients, the number of revision arthroplasties will also increase. Femoral bone loss, joint instability and possible infections are a challenge for a surgeon performing revision arthroplasty of the hip. The severe proximal femoral bone loss indicates the use of revision stems with a distal fixation. MATERIALS AND METHODS: In this study the clinical and radiological outcomes of 79 cementless stem revisions using the MRP Titan Revision Stem with an average follow-up time of 4 years were prospectively examined. RESULTS: The Harris Hip Score improved from preoperative 50.8+/-25.2 to postoperative 86.8+/-13.2. In all cases healing of bony defects could be found. For stem diameters larger than 17 mm, atrophy of the proximal femur and non-progressive radiolucent lines in zones 1 and 7 according to Gruen were detected. No disadvantages or complications of the Morse taper junctions were observed, and no osteolysis was detected in this region. Primary stable fixation was achieved in all but two cases. Three cases were revised again due to periprosthetic fracture (1) and persisting infection (2). CONCLUSION: Given the encouraging results with the MRP Titan Revision Stem, the principle of uncemented diaphyseal fixation appears to solve most of the technical problems in cases of significant bone loss and obviously offers good preconditions for bony restoration.
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Artroplastia de Reemplazo de Cadera , Prótesis de Cadera , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Diseño de Prótesis , Falla de Prótesis , Reoperación , Resultado del TratamientoRESUMEN
INTRODUCTION: Giant cell tumor of the distal fibula is a very rare condition. The treatment of advanced tumors at this location can be challenging and has been described in the literature only in single cases. MATERIALS AND METHODS: We report on a patient with a stage III giant cell tumor, according to the classification of Campanacci, of the distal fibula after en bloc resection and distal fibula reconstruction with a long bone graft from the iliac crest in a second procedure. The syndesmosis was reconstructed with a periosteal flap, the capsule and ligaments with local scar tissue. RESULTS: Fifteen years after the initial treatment the patient is free of local recurrence and demonstrates an excellent clinical outcome without any signs of instability, loss of function or osteoarthritis of the ankle joint. CONCLUSION: We suggest the method to be worthwhile for treatment of this uncommon lesion in terms of recurrence and functional outcome.
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Neoplasias Óseas/cirugía , Trasplante Óseo/métodos , Peroné , Tumor Óseo de Células Gigantes/cirugía , Ilion/trasplante , Adulto , Neoplasias Óseas/diagnóstico por imagen , Neoplasias Óseas/patología , Femenino , Estudios de Seguimiento , Tumor Óseo de Células Gigantes/diagnóstico por imagen , Tumor Óseo de Células Gigantes/patología , Humanos , Estadificación de Neoplasias , Procedimientos Ortopédicos/métodos , Radiografía , Procedimientos de Cirugía Plástica/métodos , Medición de Riesgo , Factores de Tiempo , Resultado del TratamientoRESUMEN
INTRODUCTION: Shot peening is widely used for surface treatment of hip implants. Shot peening with steel balls followed by a cleaning process with glass beads is used for introduction of negative stress in the production of morse taper junctions of the MRP-Titan stem. An increasing number of publications in maxillofacial surgery and orthopaedic surgery show that there is a significant contamination of Alumina or glass blasted surfaces. Latest research suggested an association between contaminant particles with early loosening of endoprostheses (third body wear). The aim of this study is to evaluate the amount and the effects of surface contamination with glass particles on morse taper junctions of implants and explants of the MRP-Titan stem. MATERIAL AND METHOD: The surface of morse taper junctions of the MRP-Titan stem (5 original-package implants and explants each) are analysed for glass particle contamination. A field emission scanning electron microscopy (LEO 1525) is used for the detection of the glass-particles on the implant surface with a backscattered electron detector. The relative surface area covered by particles was calculated by means of an image analyzing software (analySIS, Soft Imaging System GmbH). RESULTS: The surface of the implants showed a considerable contamination with glass particles with a mean of 6.67 +/- 0.82% compared to 2.06 +/- 0.74% on the surface of the explants. The difference was statistically significant (p<0.0001). DISCUSSION: The results of this study show that there is a relative high percentage of contamination with glass particles on shot peened morse taper junctions of the MRP-Titan stem. This contamination is significantly lower on the surface of the explants. With respect to third body wear and osteolysis in total hip arthroplasty further studies are necessary to minimize contamination while maintaining adequate surface quality.