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1.
Arch Orthop Trauma Surg ; 142(5): 763-768, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-33389020

RESUMO

INTRODUCTION: Cementless femoral revision total hip arthroplasty (RTHA) after periprosthetic fracture, aseptic loosening or infection is a challenging surgical procedure. The aim of this study was to evaluate the incidence and reasons for failure after two-stage septic revision, periprosthetic fracture or aseptic loosening that may reveal a rationale for cementless RTHA in two-stage revisions. MATERIALS AND METHODS: A consecutive series of 105 cases using cementless femoral revision prostheses were evaluated retrospectively. Indications for revision were 39 two-stage revisions after infection, 49 aseptic loosenings, and 17 periprosthetic fractures. A Kaplan-Meier analysis was performed using infection with or without removal of the implant as an endpoint. RESULTS: Incidence of infection with or without implant removal was significantly higher in patients treated for periprosthetic fractures compared to two-stage revisions or aseptic loosening (log-rank P < 0.0001). The mean follow-up period was 6.4 (2.0-13.7) years. Using infection with or without implant removal as the endpoint, 12 patients were diagnosed after the index operation resulting in a cumulative risk after 13.7 years of 29.9% (95% CI 0-61.2). CONCLUSION: Cementless revision using a modular tapered device is reliable with respect to reinfection risk in two-stage procedures.


Assuntos
Artroplastia de Quadril , Prótese de Quadril , Fraturas Periprotéticas , Artroplastia de Quadril/métodos , Seguimentos , Prótese de Quadril/efeitos adversos , Humanos , Fraturas Periprotéticas/epidemiologia , Fraturas Periprotéticas/etiologia , Fraturas Periprotéticas/cirurgia , Desenho de Prótese , Falha de Prótese , Reoperação/efeitos adversos , Estudos Retrospectivos , Fatores de Risco
2.
J Orthop ; 22: 33-37, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32280166

RESUMO

INTRODUCTION: Demographic change and demand for high quality of life lead to increasing implantation numbers. Aim of this study was to compare the Plasmafit® cup to Allofit® and Plasmacup®. METHODS: The study included 174 patients who had received 33 Plasmacup®, 68 Allofit® and 73 Plasmafit® cup implants. These were reviewed postoperatively, after 6 months control and after 12 months. RESULTS: No significant progressive migration could be discovered in any of the cup systems. At each follow-up the cups showed nearly constant values. CONCLUSIONS: All examined acetabular cups showed excellent migration behavior within the first 12 postoperative months.

3.
J Orthop ; 19: 229-232, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32071519

RESUMO

BACKGROUND: Snowboarding is a very common sport especially among young adults. Common injuries are hand, wrist, shoulder and ankle injuries. PURPOSE: of this study was to analyze different injury pattern in children and young adults comparing with adults. METHODS: Patients who were admitted for ambulant or stationary treatment as a result of injury practicing snowboard received a questionnaire and were divided into three groups (children, young adults and adults) according to their age. Between october 2002 and may 2007 1929 injured snowboard sportsmen were included in the study. Data such as location, date and time of accident as well as information about the slope were carried out. In addition snowboard skills were classified and patients were questioned whether they wore special protectors. RESULTS: 32.5% of injured patients were female (n = 626) and 67.5% male (n = 1303) with a mean age of patients of 21.9 (7-66) years. 13% of all patients were in group I (children), 19.2% in group II (young adults) and 67.8% in group III (adults).Most common injuries with 60% of all accidents were injuries of the hand wrist especially in children beginning with snowboard sports. Injuries on the regular track were most common followed by jumps in the kicker park and rails in the fun-park. 20.6% in group I, 13.6% in group II and 12.8% group III did not wear any protectors. CONCLUSION: Children and adolescents presented different injury patterns than adults. Young participants of up to 14 years of age are endangered especially during the first days of learning this sport. Further development of protectors with regard to biomechanical characteristics is important to achieve an optimal protective effect. LEVEL OF EVIDENCE: 2b.

4.
Arch Orthop Trauma Surg ; 139(6): 843-849, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30887123

RESUMO

INTRODUCTION: High loosening rates after distal femoral replacement may be due to implant design not adapted to specific anatomic and biomechanical conditions. MATERIALS AND METHODS: A modular tumor system (MUTARS®, Implantcast GmbH) was implanted with either a curved hexagonal or a straight tapered stems in eight Sawbones® in two consecutively generated bone defect (10 cm and 20 cm proximal to knee joint level). Implant-bone-interface micromotions were measured to analyze main fixation areas and to characterize the fixation pattern. RESULTS: Although areas of highest relative micromotions were measured distally in all groups, areas and lengths of main fixation differed with respect to stem design and bone defect size. Regardless of these changes, overall micromotions could only be reduced with extending bone defects in case of tapered stems. CONCLUSIONS: The tapered design may be favorable in larger defects whereas the hexagonal may be advantageous in defects located more distally.


Assuntos
Interface Osso-Implante/fisiologia , Fêmur , Procedimentos Ortopédicos/instrumentação , Procedimentos de Cirurgia Plástica/instrumentação , Fêmur/fisiologia , Fêmur/cirurgia , Humanos , Desenho de Prótese
5.
Acta Chir Orthop Traumatol Cech ; 85(1): 54-56, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30257770

RESUMO

PURPOSE OF THE STUDY With the concept of the lateral compression plate (LLCP) a technique has been available designed to combine the advantages of a fixed-angle fixation with a complete sinking of the implant into the proximal bone. The objective of the present study was to investigate the results of the LLCP compared with classical screw osteosynthesis (SO). MATERIAL AND METHODS 31 patients with pes planovalgus who received calcaneal displacement osteotomy and osteosyntheses with screws (n = 17) or LLCP (n = 14) between 2010 and 2015 were investigated retrospectively.The ankle-hindfoot scale, Kaikkonen score, VAS, and the SF-36 were determined preoperatively as well as at the last clinical follow-up. In addition, a radiological control of osseous integration was performed in all patients 12 weeks after surgery. RESULTS With regard to clinical scores both methods depicted significant improvement. In the overall cohort there were no pseudarthroses. In the SO group 5 cases (29%) showed hardware irritation, in the LLCP group there were none. Results in the LLCP group were significantly superior in the area of the physical section of the SF 36. CONCLUSIONS Based on the results of our study, surgical treatment of stage II pes planovalgus by means of calcaneal displacement osteotomy using the LLCP is equivalent to SO with a lower incidence of hardware irritation. Key words:pes planovalgus, lateral compression plate, osteosynthesis, screw, hardware irritation. LEVEL OF EVIDENCE: Level IV, retrospective case serie.


Assuntos
Pé Chato/cirurgia , Fixação Interna de Fraturas , Osteotomia , Complicações Pós-Operatórias , Lesões dos Tecidos Moles , Placas Ósseas , Parafusos Ósseos , Calo Ósseo/diagnóstico por imagem , Calcâneo/cirurgia , Pesquisa Comparativa da Efetividade , Feminino , Pé Chato/diagnóstico , Fixação Interna de Fraturas/efeitos adversos , Fixação Interna de Fraturas/instrumentação , Fixação Interna de Fraturas/métodos , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Osteotomia/efeitos adversos , Osteotomia/instrumentação , Osteotomia/métodos , Avaliação de Resultados em Cuidados de Saúde , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Lesões dos Tecidos Moles/diagnóstico , Lesões dos Tecidos Moles/etiologia , Lesões dos Tecidos Moles/prevenção & controle
6.
Knee ; 25(3): 392-397, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29551277

RESUMO

BACKGROUND: Unicompartmental knee arthroplasty (UKA) is an effective treatment for patients with medial osteoarthritis of the knee joint. Instrumented gait analysis provides an objective measure to quantify and qualify postoperative changes of gait. The purpose of this study was to evaluate standardized instrumented gait analysis for functional recovery and gait as an outcome of mobile-bearing UKA in patients with medial osteoarthritis of the knee. METHODS: Twenty-one patients with isolated medial osteoarthritis of the knee joint received mobile-bearing UKA. They were examined by a gait analysis before surgery and after an average follow-up time of seven months. Gait analysis was performed on a treadmill with six infrared-cameras to identify changes of gait characteristics (e.g., velocity, stride time, stride length, knee adduction and hip abduction). RESULTS: Mean velocity (chosen by individuals) increased from 0.61 to 0.76m/s and further significant advancements, particularly in the knee adduction and the hip abduction were detected. Time and length of strides improved significantly as well as the clinical scores American Knee Society Score (AKSS), Oxford-12, Hannover Functional Ability Questionnaire for Osteoarthritis (FFbH-OA) Score and Devane Score. CONCLUSION: Mobile-bearing UKA can restore physiological axis of the leg and improve gait and function of the knee joint. The combination of instrumented gait analysis with clinical scores constitutes an eligible measuring instrument to quantify and qualify changes in patients' gait patterns.


Assuntos
Artroplastia do Joelho/métodos , Marcha/fisiologia , Osteoartrite do Joelho/fisiopatologia , Osteoartrite do Joelho/cirurgia , Idoso , Artroplastia do Joelho/instrumentação , Feminino , Humanos , Joelho/fisiopatologia , Articulação do Joelho/cirurgia , Prótese do Joelho , Masculino , Pessoa de Meia-Idade , Recuperação de Função Fisiológica
7.
Bone Joint J ; 97-B(1): 89-93, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25568419

RESUMO

Hypovitaminosis D has been identified as a common risk factor for fragility fractures and poor fracture healing. Epidemiological data on vitamin D deficiency have been gathered in various populations, but the association between vertebral fragility fractures and hypovitaminosis D, especially in males, remains unclear. The purpose of this study was to evaluate serum levels of 25-hydroxyvitamin D (25-OH D) in patients presenting with vertebral fragility fractures and to determine whether patients with a vertebral fracture were at greater risk of hypovitaminosis D than a control population. Furthermore, we studied the seasonal variations in the serum vitamin D levels of tested patients in order to clarify the relationship between other known risk factors for osteoporosis and vitamin D levels. We measured the serum 25-OH D levels of 246 patients admitted with vertebral fractures (105 men, 141 female, mean age 69 years, sd 8.5), and in 392 orthopaedic patients with back pain and no fractures (219 men, 173 female, mean age 63 years, sd 11) to evaluate the prevalence of vitamin D insufficiency. Statistical analysis found a significant difference in vitamin D levels between patients with vertebral fragility fracture and the control group (p = 0.036). In addition, there was a significant main effect of the tested variables: obesity (p < 0.001), nicotine abuse (p = 0.002) and diabetes mellitus (p < 0.001). No statistical difference was found between vitamin D levels and gender (p = 0.34). Vitamin D insufficiency was shown to be a risk factor for vertebral fragility fractures in both men and women.


Assuntos
Fraturas Espontâneas/epidemiologia , Fraturas por Osteoporose/epidemiologia , Fraturas da Coluna Vertebral/epidemiologia , Deficiência de Vitamina D/epidemiologia , Vitamina D/análogos & derivados , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Densidade Óssea , Estudos de Coortes , Comorbidade , Feminino , Seguimentos , Fixação de Fratura/métodos , Fraturas Espontâneas/diagnóstico por imagem , Fraturas Espontâneas/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Fraturas por Osteoporose/diagnóstico por imagem , Fraturas por Osteoporose/terapia , Prevalência , Estudos Prospectivos , Radiografia , Medição de Risco , Distribuição por Sexo , Fraturas da Coluna Vertebral/diagnóstico por imagem , Resultado do Tratamento , Vitamina D/sangue , Deficiência de Vitamina D/diagnóstico
8.
Knee Surg Sports Traumatol Arthrosc ; 23(7): 2049-54, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24671384

RESUMO

PURPOSE: Patients with lateral osteoarthritis of the knee suffer not only from pain but also impaired gait and limited mobility. Common treatment options are total knee replacement and lateral unicompartmental knee arthroplasty (UKA). The domed lateral mobile-bearing Oxford Uni is a new treatment option for patients with isolated osteoarthritis of the lateral compartment of the knee joint. We used instrumented gait analysis and clinical scores to study patients before and after lateral UKA. METHODS: Nineteen patients suffering from lateral osteoarthritis underwent implantation of a mobile-bearing lateral UKA. They were examined in a gait analysis before the operation and after an average follow-up time of 7 months. Gait analysis was performed on a treadmill with six infrared cameras to identify gait characteristics (e.g. velocity, stride time, stride length, knee abduction or hip adduction). RESULTS: Mean velocity changed from 0.58 to 0.73 m/s. Significant advancements were also found in knee abduction and hip adduction. Time and length of strides improved significantly as well as the clinical scores American Knee Society Score, Oxford-12, FFb-H-OA and Devane Score. CONCLUSION: Patients with lateral osteoarthritis of the knee showed an impaired gait with an increased knee abduction and hip adduction angle. Implantation of a lateral mobile UKA can restore normal axis of the leg and improve gait and function of the knee. Instrumented gait analysis is a suitable measuring instrument to quantify and qualify the post-operative change of gait. LEVEL OF EVIDENCE: II.


Assuntos
Artroplastia do Joelho , Marcha , Osteoartrite do Joelho/fisiopatologia , Osteoartrite do Joelho/cirurgia , Artroplastia do Joelho/instrumentação , Humanos , Articulação do Joelho/cirurgia , Amplitude de Movimento Articular , Resultado do Tratamento
9.
Rev Esp Cir Ortop Traumatol ; 57(1): 15-20, 2013.
Artigo em Espanhol | MEDLINE | ID: mdl-23594978

RESUMO

While options for operative treatment of leg axis varus malalignment in patients with medial gonarthrosis include several established procedures, such as unicompartmental knee arthroplasty (UKA), total knee arthroplasty (TKA), or high tibial osteotomy (HTO), so far there has been little focus on a less invasive option introduced more recently: the UniSpacer™ implant, a modern, self-centering, metallic interpositional device for the knee. This study evaluates whether alignment correction can be achieved by UniSpacer™ arthroplasty as well as alignment change in the first 5 postoperative years is evaluated. Antero-posterior long leg stance radiographs of 15 legs were digitally analyzed to assess alignment change: two relevant angles and the deviation of the mechanical axis of the leg were analyzed before and after surgery. Additionally, the change of the postoperative alignment was determined one and five years postoperatively. Analyzing the mechanical tibiofemoral angle, a significant leg axis correction was achieved, with a mean valgus change of 4.7±1.9°; a varus change occurred in the first postoperative year, while there was no significant further change of alignment seen five years after surgery. The UniSpacer™ corrects malalignment in patients with medial gonarthrosis; however, a likely postoperative change in alignment due to implant adaptation to the joint must be considered before implantation.


Assuntos
Artroplastia do Joelho/instrumentação , Coxa Vara/cirurgia , Hemiartroplastia/instrumentação , Prótese do Joelho , Osteoartrite do Joelho/cirurgia , Idoso , Artroplastia do Joelho/métodos , Coxa Vara/complicações , Feminino , Seguimentos , Hemiartroplastia/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/complicações , Estudos Retrospectivos , Resultado do Tratamento
10.
Rev. esp. cir. ortop. traumatol. (Ed. impr.) ; 57(1): 15-20, ene.-feb. 2013. ilus
Artigo em Espanhol | IBECS | ID: ibc-109085

RESUMO

Aunque entre las opciones del tratamiento operatorio de la desalineación en varo del eje de la pierna en pacientes con gonartrosis medial se incluyan varios procedimientos consolidados como, por ejemplo, la artroplastia unicompartimental de rodilla (AUR), la artroplastia total de rodilla (ATR) o la osteotomía tibial valguizante (OTV), hasta ahora no se ha prestado demasiada atención a una opción menos invasiva de reciente introducción: el implante UniSpacer™, un dispositivo interposicional, autocentrador y metálico para la rodilla. En el presente estudio (14 pacientes, 15 rodillas) nos dedicamos a evaluar si es posible corregir la alineación realizando una artroplastia con el UniSpacer™, así como el cambio de alineación que se produce en los 5 años posteriores a la intervención quirúrgica. Se han analizado digitalmente las radiografías anteroposteriores en carga de 15 rodillas para calcular el cambio de alineación: se analizaron 2 ángulos relevantes y la desviación del eje mecánico de la pierna antes y después de la intervención quirúrgica. Además, se determinó el cambio de la alineación posoperatoria transcurridos entre uno y 5 años. Al analizar el ángulo tibiofemoral mecánico, observamos que se logró una corrección significativa del eje de la pierna, con una media de cambio en valgo de 4,7±1,9°. Durante el primer año posterior a la intervención quirúrgica se produjo un cambio en varo, aunque no se detectó ningún cambio adicional significativo de alineación durante los 5 años posteriores a la intervención quirúrgica. El UniSpacer™ corrige eficientemente la desalineación de algunos pacientes con gonartrosis medial. No obstante, antes de proceder a la implantación deberá tenerse en cuenta la posibilidad de que se produzcan cambios posoperatorios adicionales no inmediatos de la alineación como consecuencia de la adaptación del implante (AU)


While options for operative treatment of leg axis varus malalignment in patients with medial gonarthrosis include several established procedures, such as unicompartmental knee arthroplasty (UKA), total knee arthroplasty (TKA), or high tibial osteotomy (HTO), so far there has been little focus on a less invasive option introduced more recently: the UniSpacer™ implant, a modern, self-centering, metallic interpositional device for the knee. This study evaluates whether alignment correction can be achieved by UniSpacer™ arthroplasty as well as alignment change in the first 5 postoperative years is evaluated. Antero-posterior long leg stance radiographs of 15 legs were digitally analyzed to assess alignment change: two relevant angles and the deviation of the mechanical axis of the leg were analyzed before and after surgery. Additionally, the change of the postoperative alignment was determined one and five years postoperatively. Analyzing the mechanical tibiofemoral angle, a significant leg axis correction was achieved, with a mean valgus change of 4.7±1.9°; a varus change occurred in the first postoperative year, while there was no significant further change of alignment seen five years after surgery. The UniSpacer™ corrects malalignment in patients with medial gonarthrosis; however, a likely postoperative change in alignment due to implant adaptation to the joint must be considered before implantation (AU)


Assuntos
Humanos , Masculino , Feminino , Osteoartrite do Joelho/cirurgia , Mau Alinhamento Ósseo/cirurgia , Osteoartrite/complicações , Osteoartrite/diagnóstico , Osteoartrite/cirurgia , Próteses e Implantes/tendências , Próteses e Implantes , Estudos Retrospectivos , Próteses e Implantes/normas , Artroplastia/métodos , Artroplastia/tendências
11.
J Bone Joint Surg Am ; 95(1): 48-53, 2013 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-23283372

RESUMO

BACKGROUND: Aseptic loosening is the most common cause for revision unicompartmental knee arthroplasty and is associated with failure of the bone-cement or cement-implant interface. The purpose of the present study was to analyze different bone lavage techniques for the bone-cement and cement-implant interfaces of the femoral component and to study the effect of these techniques on cement penetration and on interface temperature. METHODS: In an experimental cadaver study, Oxford unicompartmental knee arthroplasty was performed in twenty-four matched-paired knees to study the effect of pulsed lavage compared with syringe lavage on femoral cement penetration and interface temperature. Interface temperature, cement penetration pressure, and ligament tension forces were measured continuously during the procedure, and cement penetration was determined by performing sagittal bone cuts. RESULTS: Cleansing the femoral bone stock with use of pulsed lavage (Group B) led to increased femoral cement penetration (mean, 1428 mm²; 95% confidence interval, 1348 to 1508 mm²) compared with syringe lavage (Group A) (mean, 1128 mm²; 95% confidence interval, 1038 to 1219 mm²) (p < 0.001). Interface temperature was higher in Group B (mean 22.6°C; 95% confidence interval, 20.5°C to 24.1°C) than in Group A (mean, 21.0°C; 95% confidence interval, 19.4°C to 23.0°C) (p = 0.028), but temperatures never reached critical values for thermal damage to the bone. CONCLUSIONS: Pulsed lavage leads to an increased femoral cement penetration without the risk of heat necrosis at the bone-cement interface.


Assuntos
Artroplastia do Joelho/métodos , Temperatura Corporal , Cimentos Ósseos/química , Irrigação Terapêutica/métodos , Cimentação , Fêmur , Humanos , Polimerização
12.
Open Orthop J ; 6: 488-94, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23193432

RESUMO

A consecutive series of 52 acetabular revisions was evaluated retrospectively. Inclusion criteria for all patients were at least one former exchange of the acetabular component. Reconstruction was performed with reliable techniques and implants other than extensively porous coated device (e.g. tantalum). The mean follow up was 5.63 (0.01-14.05) years. Cumulative survival at 14.05 years with removal of the acetabular component due to aseptic loosening or the worst case criterion (removal of the acetabular component for any cause and/or lost to follow-up) as the end point was 66.38 (95 % C.-I.: 47.80-84.96) % and 58.42 (95 % C.-I.: 41.01-75.83) %, respectively. The cumulative survival rate with mechanical failure of the acetabular reconstruction as the endpoint was significantly lower in patients with two or more previous revisions in comparison to those with only one former procedure (log rank test: p=0,0112 respectively). The mean Merle d'Aubignée-score improved from 7.3 (0-14) preoperatively to 10.6 (0-17) points at latest follow up examination.Survival of acetabular reconstructions with common techniques and implants is decreasing with the number of previous revisions. This may cause major concerns with regard to the rising number of patients needing repeated revisions. Maximizing durability of primary THA, precise preoperative planning as well as improved techniques and implants for revision may decrease this problem in the long term.

13.
Technol Health Care ; 20(6): 535-43, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23187019

RESUMO

INTRODUCTION: The present feasibility study examined the use of an ultrasound-based navigation system (UNS) for reliability of measurement the positions of both the femoral and acetabular components, a prerequisite to adjust the combined anteversion with sufficient accuracy when using a femur-first approach in total hip arthroplasty. METHOD: Using a UNS, five investigators performed five measurements of the posterior femoral condyles and the anterior pelvic planes (APP) of two cadavers with different body mass index. Deviations in stem and acetabular anteversion resulting from varying acquisition of the respective landmarks were determined relative to the reference measures of anteversion determined in the same cadavers from computed tomography (CT) scans. Here, both a freehand and guided ultrasound measurement methods were used to acquire the posterior femoral condyles. Femoral and acetabular anteversion values were added in order to estimate the combined anteversion of the reconstructed hip. RESULTS: Using an UNS, variations in the freehand technique for the acquisition of the posterior femoral condyles resulted in a mean error in the anteversion of the femoral component of -1.5° (SD 3.4°; -10.8° to 7.0°) while the mean error was -0.9° (SD 3.1°; -7.3° to 10.2°) when the UNS provided additional support to standardize the orientation of the UNS probe. In all cases, UNS navigation enabled to achieve combined anteversion values that fell within a clinically acceptable error range of less than ± 12.5° compared to the CT measures. CONCLUSION: Our investigations suggest that the anteversion of stem and cup can be measured with accuracy sufficient enough to utilize the concept of combined anteversion using UNS. Hence, the advantage of utilizing UNS's in a femur-first approach is the ability to intraoperatively compensate for deviations from the targeted anteversion of the stem (which is often difficult to control) by adjusting the acetabular anteversion in the final step of the implantation. In doing so, the placement of the components follows the concept of combined anteversion. Avoiding extreme anteversion values of combined anteversion could be an important step towards reducing post-operative complications following total hip arthroplasty (THA).


Assuntos
Artroplastia de Quadril/métodos , Fêmur/anatomia & histologia , Cirurgia Assistida por Computador/métodos , Ultrassonografia de Intervenção/métodos , Acetábulo/diagnóstico por imagem , Idoso , Cadáver , Feminino , Fêmur/diagnóstico por imagem , Humanos , Tomografia Computadorizada por Raios X
14.
Knee Surg Sports Traumatol Arthrosc ; 20(6): 1087-91, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22002301

RESUMO

PURPOSE: Periprosthetic tibial plateau fractures represent a rare but serious complication in unicompartmental knee arthroplasty and are associated with extended sagittal tibial bone cuts. These can occur during the surgery, weaken the posterior cortex of the tibia and are associated with periprosthetic tibial plateau fractures. Although excellent long-term results have been reported with cemented unicompartmental knee arthroplasty, there is high interest in cementless fixation. The aim of the study was to compare fracture loads of cementless and cemented unicompartmental knee arthroplasty. METHODS: Tibial components of the Oxford Uni were implanted in six paired fresh-frozen tibiae with a defined extended saw cut (10°) at the dorsal cortex of each specimen. In one set, surgery was performed with cement fixation, and in the other, cementless components were implanted. Vertical loads were then applied under standardised conditions to fracture the specimens. RESULTS: Median loads of 3.7 (0.7-6.9) kN led to fractures in the cemented group, whereas cementless fixated tibiae fractured with a median load of 1.6 (0.2-4.3) kN (P = 0.02). CONCLUSION: The loading capacity in tibiae with cementless components is significantly less compared to cemented fixation. The results show that in case of an extended sagittal bone cut patients especially those with poor bone quality who are treated with a cementless unicompartmental knee arthroplasty are at higher risk for periprosthetic tibial fractures.


Assuntos
Artroplastia do Joelho/instrumentação , Cimentos Ósseos , Prótese do Joelho , Osteotomia/métodos , Complicações Pós-Operatórias/prevenção & controle , Tíbia/cirurgia , Fraturas da Tíbia/prevenção & controle , Artroplastia do Joelho/métodos , Feminino , Humanos , Masculino , Tíbia/fisiologia , Fraturas da Tíbia/etiologia , Suporte de Carga
15.
Clin Biomech (Bristol, Avon) ; 27(4): 372-6, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22051198

RESUMO

BACKGROUND: Mechanical loosening is the most common cause of revision in unicompartmental knee arthroplasty. We determined the effect of bone lavage on tibial cement penetration and interface temperature with controlled ligament tension forces. We presumed pulsed lavage would allow increased cement penetration compared with syringe lavage. METHODS: Cemented unicompartmental knee arthroplasty was performed in 12 pairs of fresh-frozen knees. Lavage was performed using pulsed lavage on one side (A) and syringe lavage on the other (B). Cement penetration pressure, interface temperature, and ligament tension forces were continuously monitored during the operation. Screened radiographs were taken and cement penetration under the tibial plateau was measured. FINDINGS: The pulsed lavage group showed a mean cement penetration area of 187.24 (SD 36.37) mm², whereas 144.29 (SD 35.74) mm(2) was measured in the group with syringe lavage. Cement penetration pressure was 13.29 (SD 8.69) kPa in Group A and 20.21 (SD 7.78) kPa in Group B. Maximum interface temperatures of 46.99°C were observed in Group A and 45.02°C in Group B. INTERPRETATION: Our data showed pulsed lavage cleansing of the cancellous tibial bone substantially improved cement penetration compared with syringe lavage without reaching the temperature threshold for bone necrosis. We recommend the routine use of pulsed lavage to improve long-term fixation.


Assuntos
Artroplastia do Joelho/instrumentação , Artroplastia do Joelho/métodos , Cimentos Ósseos/química , Cimentação/métodos , Ligamentos Articulares/química , Irrigação Terapêutica/métodos , Tíbia/química , Adesividade , Adulto , Idoso , Idoso de 80 Anos ou mais , Cadáver , Feminino , Humanos , Masculino , Teste de Materiais , Fluxo Pulsátil , Estresse Mecânico , Propriedades de Superfície , Temperatura , Resistência à Tração/fisiologia
16.
Knee ; 17(1): 57-60, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19539478

RESUMO

Periprosthetic tibial plateau fractures (TPF) are rare but represent a serious complication of unicompartmental knee arthroplasty (UKA). As TPFs usually occur perioperatively, these can be associated with extended sagittal saw cuts during surgery. The aim of the study was to evaluate TPF as a function of extended sagittal saw cuts. The hypothesis was that extended sagittal saw cuts reduce the loading capacity of the tibial plateau and increase the risk of periprosthetic TPF. In a randomised study, standardised cemented Oxford UKA tibial component implantation was performed in six matched, paired fresh-frozen tibiae. In group A, a regular preparation of the tibial plateau was performed, whereas in group B a standardised extended sagittal saw cut was made at the dorsal cortex of the tibia. All tibiae were fractured under standardised conditions and fracture patterns and fracture loads were analysed. In group A, tibiae fractured with a mean load of F(max)=3.9 (2.3-8.5) kN, whereas in group B fractures occurred at a mean load of F(max)=2.6 (1.1-5.0) kN. The difference was statistically significant (p<0.05). Extended sagittal saw cuts in UKA weaken the tibial bone structure. Our results show that descendent extended sagittal saw cuts of 10 degrees reduce fracture loads by about 30%. Surgeons should be aware of the potential pitfalls of an extended sagittal saw cut, as this can lead to reduced loading capacity of the tibial plateau and increase the risk of periprosthetic TPF.


Assuntos
Artroplastia do Joelho/efeitos adversos , Análise de Falha de Equipamento , Complicações Intraoperatórias/prevenção & controle , Prótese do Joelho , Fraturas da Tíbia/etiologia , Idoso , Idoso de 80 Anos ou mais , Artroplastia do Joelho/instrumentação , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , Estresse Mecânico , Tíbia/diagnóstico por imagem , Tíbia/lesões , Fraturas da Tíbia/diagnóstico por imagem
17.
Knee ; 17(6): 398-402, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20006930

RESUMO

Femoral component loosening is a rare but serious complication in cemented Oxford unicompartmental knee arthroplasty (OUKA). In a cadaver study, OUKA was performed in 24 knees to evaluate the femoral fixation pattern. Due to the geometry of bone and implant, three different zones were identified. Complete cement mantles and good interdigitation were found in the spherical part of the implant (zone 1) and around the peg (zone 3), which implies that these are most important for implant fixation. The posterior plane facet (zone 2) is the weak point of the interface due to incompleteness of the cement mantle and a lack of interdigitation. This study suggests that the cancellous bone in zone 2 and the drill holes in sclerotic bone areas should be filled with cement and pressurised prior to component seating.


Assuntos
Artroplastia do Joelho/métodos , Cimentos Ósseos , Fêmur/cirurgia , Articulação do Joelho/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Cirurgia Assistida por Computador/métodos , Artroplastia do Joelho/instrumentação , Cadáver , Cimentação/métodos , Fêmur/anatomia & histologia , Humanos , Prótese do Joelho , Falha de Prótese
18.
Unfallchirurg ; 112(12): 1066-9, 2009 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-19998022

RESUMO

Subtalar dislocations represent uncommon injuries of the foot. Leitner [7] described the relationship between medial and lateral dislocations as 6:1. The mechanism is a trauma in plantar flexion/supination of the forefoot with a fixed hindfoot.Immediate reduction, which can usually be performed as a closed reduction is the aim of the treatment. The reduction should be performed under anesthesia in the operating room (OR) and under OR conditions in case the closed reduction shows no success. Subsequently, x-rays and CT scans should be performed in two planes in order to rule out concomitant injuries at the processus posterior tali and the talar head, as bony fragments can necessitate an operative intervention in the case of an interposition of the articulation.In terms of aftercare an immobilization of 6 weeks with a lower leg cast is suggested in the literature. In the presented case an early functional therapy with 2 weeks cast and 4 weeks with a therapy boot could achieve good clinical results.


Assuntos
Traumatismos em Atletas/terapia , Luxações Articulares/terapia , Manipulação Ortopédica , Futebol/lesões , Articulação Talocalcânea/lesões , Adulto , Traumatismos em Atletas/diagnóstico por imagem , Seguimentos , Humanos , Luxações Articulares/diagnóstico por imagem , Masculino , Articulação Talocalcânea/diagnóstico por imagem , Tomografia Computadorizada por Raios X
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