RESUMEN

BACKGROUND: Stronger resting-state functional connectivity of the default mode and frontoparietal control networks has been associated with cognitive resilience to Alzheimer's disease related pathology and neurodegeneration in smaller cohort studies. OBJECTIVES: We investigated whether these networks are associated with longitudinal CR to AD biomarkers of beta-amyloid (Aß). DESIGN: Longitudinal mixed. SETTING: The Anti-Amyloid Treatment in Asymptomatic Alzheimer's Disease (A4) study and its natural history observation arm, the Longitudinal Evaluation of Amyloid Risk and Neurodegeneration (LEARN) study. PARTICIPANTS: A sample of 1,021 cognitively unimpaired older adults (mean age = 71.2 years [SD = 4.7 years], 61% women, 42% APOEε4 carriers, 52% Aß positive). MEASUREMENTS: Global cognitive performance (Preclinical Alzheimer's Cognitive Composite) was assessed over an average 5.4 year follow-up period (SD = 2 years). Cortical Aß and functional connectivity (left and right frontoparietal control and default mode networks) were estimated from fMRI and PET, respectively, at baseline. Covariates included baseline age, APOEε4 carrier status, years of education, adjusted gray matter volume, head motion, study group, cumulative treatment exposure, and cognitive test version. RESULTS: Mixed effects models revealed that functional connectivity of the left frontoparietal control network moderated the negative effect of Aß on cognitive change (p = .025) such that stronger connectivity was associated with reduced Aß-related cognitive decline. CONCLUSIONS: Our results demonstrate a potential protective effect of functional connectivity in preclinical AD, such that stronger connectivity in this network is associated with slower Aß-related cognitive decline.

Asunto(s)

Enfermedad de Alzheimer , Péptidos beta-Amiloides , Disfunción Cognitiva , Lóbulo Frontal , Imagen por Resonancia Magnética , Lóbulo Parietal , Humanos , Femenino , Masculino , Anciano , Péptidos beta-Amiloides/metabolismo , Lóbulo Parietal/diagnóstico por imagen , Estudios Longitudinales , Lóbulo Frontal/diagnóstico por imagen , Tomografía de Emisión de Positrones , Síntomas Prodrómicos , Red Nerviosa/diagnóstico por imagen , Red Nerviosa/fisiopatología

RESUMEN

BACKGROUND: The natural course of shoulder instability is still not entirely clear. We aimed in this review to analyse the current scientific evidence of the natural history of shoulder instability. MATERIALS AND METHODS: A systematic review of the English literature was performed using the PubMED database throughout January 2014. This review was guided, conducted and reported according to PRISMA criteria. The criteria for inclusion in the study were (1) the article was written in English, (2) the level of evidence was 1-4, (3) the article was available in full text, (4) the article investigated the natural history or course of shoulder instability, the outcome of non-operative management, or the regression of the shoulder symptoms to the mean. The methodological quality of each included study was individually assessed using a newly developed general assessment tool-Assessing the Methodological Quality of Published Papers (AMQPP). RESULTS: Eight articles related to shoulder instability met the inclusion criteria. Four papers were considered high-quality studies (evidence level 1 and 2). One paper assessed the natural history and the natural course of shoulder instability directly. The other studies indirectly assessed the natural history by studying non-operative and operative therapy trends. We found no articles which clearly referred to the role of 'regression to the mean'. CONCLUSION: Following the natural history and the implementation of standardised non-operative treatment programmes are an effective therapy and superior to surgery in many cases. However, primary acute shoulder dislocation in young active individuals partaking in demanding physical activities could benefit from early surgical intervention. The AMQPP score works as a quick quality-checking tool which helps researchers to identify the key points in each paper and reach a decision regarding the eligibility of the paper more easily. The AMQPP scoring system is still open for further development and expansion. Level of evidence Level IV.

Asunto(s)

Inestabilidad de la Articulación/etiología , Inestabilidad de la Articulación/terapia , Luxación del Hombro/etiología , Luxación del Hombro/terapia , Humanos , Procedimientos Ortopédicos , Selección de Paciente

RESUMEN

BACKGROUND: The goal of rotator cuff repair is a high initial mechanical stability as a requirement for adequate biological recovery of the tendon-to-bone complex. Notwithstanding the significant increase in publications concerning the topic of rotator cuff repair, there are still controversies regarding surgical technique. OBJECTIVES: The aim of this work is to present an overview of the recently published results of biomechanical and clinical studies on rotator cuff repair using single- and double-row techniques. MATERIALS AND METHODS: The review is based on a selective literature research of PubMed, Embase, and the Cochrane Database on the subject of the clinical and biomechanical results of single- and double-row repair. RESULTS: In general, neither the biomechanical nor the clinical evidence can recommend the use of a double-row concept for the treatment for every rotator cuff tear. Only tears of more than 3 cm seem to benefit from better results on both imaging and in clinical outcome studies compared with the use of single-row techniques. CONCLUSIONS: Despite a significant increase in publications on the surgical treatment of rotator cuff tears in recent years, the clinical results were not significantly improved in the literature so far. Unique information and algorithms, from which the optimal treatment of this entity can be derived, are still inadequate. Because of the cost-effectiveness and the currently vague evidence, the double-row techniques cannot be generally recommended for the repair of all rotator cuff tears.

Asunto(s)

Procedimientos de Cirugía Plástica/métodos , Recuperación de la Función/fisiología , Lesiones del Manguito de los Rotadores/fisiopatología , Lesiones del Manguito de los Rotadores/cirugía , Manguito de los Rotadores/fisiopatología , Técnicas de Sutura , Humanos , Procedimientos de Cirugía Plástica/instrumentación , Manguito de los Rotadores/cirugía , Lesiones del Manguito de los Rotadores/diagnóstico , Resistencia a la Tracción , Resultado del Tratamiento

RESUMEN

INTRODUCTION: The clinical superiority of the double-row technique is still a subject of controversial debate in rotator cuff repair. We hypothesised that the expression of different collagen types will differ between double-row and single-row rotator cuff repair indicating a faster healing response by the double-row technique. MATERIALS AND METHODS: Twenty-four mature female sheep were randomly assembled to two different groups in which a surgically created acute infraspinatus tendon tear was fixed using either a modified single- or double-row repair technique. Shoulder joints from female sheep cadavers of identical age, bone maturity, and weight served as untreated control cluster. Expression of type I, II, and III collagen was observed in the tendon-to-bone junction along with recovering changes in the fibrocartilage zone after immunohistological tissue staining at 1, 2, 3, 6, 12, and 26 weeks postoperatively. RESULTS: Expression of type III collagen remained positive until 6 weeks after surgery in the double-row group, whereas it was detectable for 12 weeks in the single-row group. In both groups, type I collagen expression increased after 12 weeks. Type II collagen expression was increased after 12 weeks in the double-row versus single-row group. Clusters of chondrocytes were only visible between week 6 and 12 in the double-row group. CONCLUSIONS: The study demonstrates differences regarding the expression of type I and type III collagen in the tendon-to-bone junction following double-row rotator cuff repair compared to single-row repair. The healing response in this acute repair model is faster in the double-row group during the investigated healing period.

Asunto(s)

Huesos/cirugía , Colágeno/biosíntesis , Colágenos Fibrilares/biosíntesis , Manguito de los Rotadores/cirugía , Traumatismos de los Tendones/cirugía , Tendones/cirugía , Animales , Huesos/patología , Colágeno Tipo I/biosíntesis , Colágeno Tipo II/biosíntesis , Colágeno Tipo III/biosíntesis , Modelos Animales de Enfermedad , Femenino , Manguito de los Rotadores/patología , Lesiones del Manguito de los Rotadores , Rotura , Ovinos , Técnicas de Sutura , Traumatismos de los Tendones/patología , Tendones/patología , Cicatrización de Heridas/fisiología

RESUMEN

PURPOSE: This study is aimed to compare the effects of arthroscopic joint debridement over a 5-year period in a clearly defined patient population (only grade III knee osteoarthritis, history < 2 years). MATERIAL AND METHODS: A total of 96 patients (50 male and 46 female) underwent arthroscopic knee debridement for knee OA. The main criteria for inclusion were osteoarthritis grade III (Kellgren-Lawrence score) and a maximal history of 2 years. RESULTS: The subjective complaints and the knee-related quality of life were estimated by the KOOS (knee injury and osteoarthritis outcome score). The score increased significantly within the 1 to 3 rd year post operation. After this interval the mean points of the score declined. But after 5 years the KOOS was higher in comparison to the baseline dates. Patients who had undergone conservative treatment at baseline had a significantly different KOOS than patients in the arthroscopy group. Over time, patients in the arthroscopy group had fewer complaints than patients in the conservative treatment group. In both groups, the results decreased over time. A total of 17 patients (17.2 %) needed a conversion to total endoprothetic replacement. The mean time-interval between index operation and conversion was 56.6 (95 % CI 54.4 - 58.4) months. CONCLUSIONS: In middle stages of knee OA, arthroscopic joint debridement can effectively reduce subjective complaints. Because this treatment does not stop the process of OA, the improvements decrease over time.

Asunto(s)

Artralgia/terapia , Artroscopía/métodos , Desbridamiento/métodos , Osteoartritis de la Rodilla/terapia , Modalidades de Fisioterapia , Artralgia/etiología , Terapia Combinada , Estudios de Seguimiento , Humanos , Inmovilización/métodos , Estudios Longitudinales , Osteoartritis de la Rodilla/complicaciones , Estudios Retrospectivos , Resultado del Tratamiento

RESUMEN

PURPOSE: This laboratory study aimed to evaluate the loop security, knot security, cyclic loading resistance and load-to-failure rate of three different knot types with establishing a new experimental set-up. Additionally, the mode of failure of each knot was evaluated. METHODS: With the use of nonabsorbable, braided polyethylene sutures, USP size No. 2 [Hi-Fi®; ConMed Linvatec], the arthroscopic knot types Dines, SMC as well as the surgeon's knot were tested using a material testing machine. The knots were tied openly as well as arthroscopically. The set-up enables testing of knot configurations while eliminating friction between knot loop and its suspension points. Including all test procedures, a total of 216 knots were tested. RESULTS: All openly tied knot types and ten of each type of arthroscopically tied knots resisted against cyclic loading of 1,000 cycles. With subsequent load-to-failure testing, openly tied knot types achieved significantly higher values of tensile strength than arthroscopically tied knots. Regarding clinical failure, defined as an elongation of 3 mm, Dines knot reached highest loop as well as knot security. Knot slippage was the most common failure mechanism at an elongation of 3 mm, whereas suture breakage was evaluated most at an elongation of 6 mm. CONCLUSIONS: The new experimental set-up confirms the loop security of arthroscopic knot types. Using a knot pusher clinically is a key factor to attain this as compared to openly hand-tied techniques. The Dines knot presented the highest reliability. It may provide a secure tissue healing during rehabilitation and consequently can be recommended for clinical application.

RESUMEN

Damage to hyaline cartilage is the most important pathophysiological tool in the development of osteoarthritis. Cartilage lesions are the most frequent pathological findings during arthroscopic operations. Arthroscopies as well as magnetic resonance tomography are gold standards for detection of cartilage lesions. But the arthroscopic evaluation of cartilage lesions is descriptive and subjective only. The surgeon is able to differentiate between intact cartilage surface, softening, superficial or deep fissure or flake and finally a complete defect. In routine arthroscopy the grading mostly is made by use of different scores [e.g. ICRS (International Cartilage Repair Society), Outerbridge, Insall, Jäger-Wirth or others]. Because the arthroscopic evaluation is subjective the reliability of this method is poor. Spectroscopic methods are established for evaluation of different tissue diseases in different indications. NIRS (near infrared spectroscopy) has become an important method for medical diagnostics in the last years. NIR is very energy-rich and suitable for glass fibre transport without relevant reduction. Insofar this technology may be ideal for endoscopic procedures. Our systematic literature review reveals that NIRS is a sufficient method for an objective diagnosis of cartilage lesions. In the current work we demonstrate an NIRS-based device for intraoperative, real-time cartilage evaluation. Furthermore, we discuss the possible clinical consequences from such measurements.

Asunto(s)

Algoritmos , Enfermedades de los Cartílagos/diagnóstico , Diagnóstico por Computador/métodos , Espectroscopía Infrarroja Corta/métodos , Humanos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad

RESUMEN

AIM: High tibial osteotomy (HTO) has been established as an effective method for the treatment of unicondylar knee osteoarthritis. This study was undertaken to quantify the potential for restoration of cartilage lesions or defects after HTO in relation to different cartilage treatment modalities. Control arthroscopy was undertaken to identify the cartilage lesions within the knee joint 1.5 years after medial opening wedge osteotomy. MATERIAL AND METHOD: A total of 135 patients (72 male and 63 female) had undergone medial-opening high tibial osteotomy and arthroscopy. The mean age at operation was 48.8 (36 to 65) years. All HTO were fixed with an angle-stable, mobile spacer-containing plate (HTO-Platte, Königsee, Deutschland). All HTO were combined with a simultaneous arthroscopy. Grade III cartilage lesions had undergone either shaving or temperature-controlled chondroplasty (Paragon ArthroW Austin, TX, USA). In some case these cartilage lesions had remained untreated. Control arthroscopy and removal of the implants was performed 1.5 years after HTO. The cartilage lesions were graded accordingly to the ICRS guidelines (International Cartilage Repair Society). RESULTS: The KOOS at HTO was 49.9 (SD 10.6) points. We observed at follow-up a mean increase from 66.1 (SD 28.8, 95 % CI: 61.2-71.1) points. The KOOS at follow-up was 16.1 (SD 29.8) points. There was no delayed union of the HTO space. Before HTO the varus angle was 10.4° (SD 3.9 range 5 to 20°). The correction angle was 13.6° (SD 4.4, 95 % CI: 12.9-14.4°). Finally we determined a valgus angle of -3.2° (SD 1.8 minimum 0° varus, maximum -6° valgus. The clinical outcome (KOOS) significantly (p < 0.001) correlated (R = 0.605) with the extension of valgisation. Patients with a valgus angle of 3° and more had the best outcome. Of the grade III lesions 40.4 % in the medial femoral condyle and 62.3 % in the medial tibial plateau increased to grade II or I lesions. In 13.1 % of the medial femoral condyle and 8.5 % of medial tibial plateau cases we found complete (grade IV) defects at control arthroscopy. The highest rate of regenerations was detected after temperature-controlled chondroplasty. The worst results were produced after mechanical debridement. Microfracturing of complete defects produced regeneration in about ⅔ in the medial femoral condyle and about ⅓ in the medial tibial plateau. No increase was observed within the lateral or patello-femoral compartment. No correlation was seen between cartilage regeneration and outcome. The extension of valgisation did not influence the cartilage regeneration. CONCLUSIONS: The main effect of the HTO is the shift of the weight-bearing line from the arthritic compartment to the opposite femorotibial healthy one. In addition, HTO also produces a partial restoration of cartilage lesions. Deep cartilage lesions (grade III) restore in about 60 % of the cases after HTO. The worst restoration is found after mechanical shaving. This method should be avoided in the future. The best restoration was found in deep lesions after thermochondroplasty. Furthermore, in about half of the patients with complete (grade IV) defects, microfracturing caused the formation of fibrocartilaginous regenerates. This procedure should always be performed if possible.

Asunto(s)

Cartílago Articular/patología , Cartílago Articular/cirugía , Osteoartritis de la Rodilla/patología , Osteoartritis de la Rodilla/cirugía , Osteotomía/métodos , Regeneración , Tibia/cirugía , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento

RESUMEN

INTRODUCTION: The posterior locked shoulder dislocation is a rare injury that is often associated with an impression fracture of the anteromedial aspect of the humeral head. The majority of posterior shoulder dislocations are missed on the initial examination. METHODS: We demonstrate the case of an athlete, who presented with a posterior shoulder dislocation after a trauma two months ago. RESULTS: The patient was treated with a M. subscapularis transfer in the reverse-hill-sachs-lesion. DISCUSSION: The diagnosis of the posterior shoulder dislocation remains a problem in the clinical setting. Treatment is based on the size defect of the anteromedial humeral head. Different treatment options are still controversially discussed. CONCLUSION: To diagnose a posterior shoulder dislocation correctly a standard clinical and radiological assessment is necessary.

Asunto(s)

Traumatismos en Atletas/cirugía , Inestabilidad de la Articulación/cirugía , Luxación del Hombro/cirugía , Transferencia Tendinosa/métodos , Adulto , Humanos , Inestabilidad de la Articulación/etiología , Masculino , Luxación del Hombro/complicaciones

RESUMEN

AIM: This metaanalysis was performed to evaluate the prevalence of the radiological assessed knee osteoarthritis in the whole community. MATERIALS AND METHODS: Medical databases (Medline, EMBASE, Cochrane) were searched for the strategy: ["Osteoarthritis" and "Knee" and "Prevalence"]. The deadline for the search was 31.12.2009. Two investigators (first and senior author) independently made the selection from 17 studies (from a total of 1428) according to the inclusion criteria: a cross-sectional study of the whole community, radiological investigation and definition of knee ROA by an established radiological score. Only studies in English or German language were evaluated. Effect sizes (event rate, odds ratio [OR] and confidence interval [CI]) were calculated by the software "Comprehensive Metaanalysis V2". Study heterogeneity (I2) was determined accordingly to Higgins. RESULTS: The kappa index for interobserver validity was k = 0.948. All studies judged the grade of osteoarthritis according to the Kellgren-Lawrence (KL) score. For calculation of knee ROA KL grades 2+ were estimated only. The total prevalence of knee ROA was 24.3 % (CI 23.4-25.2 %). The whole prevalence in male patients was 24.3 % (CI 23.4-25.2 %); I2 = 59.4 (p = 0.002) and in female patients 32.6 % (CI 31.8-33.4 %); I2 = 49,1 (p < 0.001). Younger male patients (age 50-) had a prevalence of 5.6 (CI 4.5-6.8). In older patients (80+) the male prevalence was 44.5 % (CI 39.6-49.5 %). In this age group female patients had a prevalence of 71.6 % (CI 67.6-75.3 %). The higher prevalence of knee ROA in female patients was significant (OR = 1.8 [1.7-1.9]; I2 = 46.0 [p < 0.001]). The prevalence of knee ROA was higher in male Asians compared with male Caucasians (OR = 1.1, CI 0.9-1.2; p = 0.080) in tendency. This difference was significant in female patients (OR = 2.2; CI 2.0-2.4; p < 0.001). Furthermore another trend was evaluated. Female patients (70-79 years) from the birth-year cohort 1920- had a prevalence of 37.8 % (CI 35.9-39.7)%. In contrast female patients from the birth-year cohort 1920 had a prevalence of 62.8 % (CI 60.8-64.8 %) at 70-79 years. This difference was significant (OR = 2.8; CI 2.5-3.1; p < 0.001). CONCLUSIONS: This investigation confirms the high prevalence of knee ROA. The evaluated data may serve as a reference for medical or scientific investigations in the future.

Asunto(s)

Osteoartritis de la Rodilla/diagnóstico por imagen , Osteoartritis de la Rodilla/etnología , Adolescente , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Femenino , Alemania/etnología , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Radiografía , Medición de Riesgo , Factores de Riesgo , Distribución por Sexo , Adulto Joven

RESUMEN

The modular endoprosthetic system Munich-Luebeck (MML) has been in clinical use since 1994. A total of 2.118 pelvic and lower extremity surgeries using the MML system were carried out up until 2010. The modular construction allows substituting or bridging any kind of bone defect. We analyzed 572 operative interventions, which were performed in 5 centers. The most frequent indications were tumors (50.3%) followed by revision arthroplasty due to loosening, periprosthetic fractures, and joint resection surgery due to infection (43.3%). Proximal and distal femoral replacement amounted to 78% of cases, whereas partial pelvic replacement accounted for 10.4% of the cases. Complications were reported in 27.27% of the cases, where dislocations (14.9% of the cases with simultaneous hip replacement) and infections (10.48%) were the most common, as expected. Revision surgery was necessary in 140 (24.8%) of the 572 patients, of which 68 were partial or total replacement of the implants, 16 removal of the implants and 10 above-knee amputations or rather exarticulations of the hip.

Asunto(s)

Articulación de la Cadera/cirugía , Prótesis de Cadera/estadística & datos numéricos , Inestabilidad de la Articulación/epidemiología , Inestabilidad de la Articulación/cirugía , Articulación de la Rodilla/cirugía , Prótesis de la Rodilla/estadística & datos numéricos , Adulto , Anciano , Análisis de Falla de Equipo , Femenino , Alemania/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Diseño de Prótesis , Resultado del Tratamiento

RESUMEN

Biodegradable implants lead to problems such as cyst formation, soft-tissue inflammation, loose implant fragments or local osteolysis. This report represents the first published case of an intraosseous foreign body granuloma in the humeral head after arthroscopic rotator cuff tear fixation with a poly-L: -lactide (PLLA) suture anchor. A 48-year-old female patient presented with pain in her right shoulder. A refixation of her right supraspinatus tendon with a biodegradable suture anchor was performed 11 months ago at an external hospital. Laboratory tests showed normal values for C-reactive protein, leukocytes and the erythrocyte sedimentation rate. No signs of infection or instability were noted. The visual analogue scale (VAS) was 8, the simple shoulder test (SST) was 4 and the American shoulder and elbow surgeons score (ASES) was 44. Plain radiographs showed high lucency in the area of the tuberculum majus. MRI showed an intra- and extraosseous mass surrounded by fluid in this area. Surgical care involved arthroscopic debridement and removal of the suture anchor. Histological examination revealed a foreign body granuloma. At the 18-month follow-up the patient was nearly pain-free. The VAS was 2, SST was 10 and ASES was 88. Foreign body granulomas are a well known but rarely described complication that arises after the use of biodegradable suture anchors in shoulder surgery. Every patient presenting with shoulder pain after usage of a biodegradable fixation material should be evaluated closely. Orthopaedic surgeons should be aware of the possibility of delayed foreign body reactions, especially after using PLLA anchors.

Asunto(s)

Implantes Absorbibles/efectos adversos , Granuloma de Cuerpo Extraño/etiología , Húmero , Lesiones del Manguito de los Rotadores , Dolor de Hombro/etiología , Anclas para Sutura/efectos adversos , Artroscopía , Desbridamiento , Femenino , Granuloma de Cuerpo Extraño/cirugía , Humanos , Persona de Mediana Edad , Dimensión del Dolor , Complicaciones Posoperatorias/cirugía , Manguito de los Rotadores/cirugía

RESUMEN

AIM: This experimental study aimed to compare the load-to-failure rate and stiffness of single- versus double-row suture techniques for repairing rotator cuff lesions using two different suture materials. Additionally, the mode of failure of each repair was evaluated. METHOD: In 32 sheep shoulders, a standardized tear of the infraspinatus tendon was created. Then, n = 8 specimen were randomized to four repair methods: (1) Double-row Anchor Ethibond coupled with polyester sutures, USP No. 2; (2) Double-Row Anchor HiFi with polyblend polyethylene sutures, USP No. 2; (3) Single-Row Anchor Ethibond coupled with braided polyester sutures, USP No. 2; and (4) Single-Row Anchor HiFi with braided polyblend polyethylene sutures, USP No. 2. Arthroscopic Mason-Allen stitches were placed (single-row) and combined with medial horizontal mattress stitches (double-row). All specimens were loaded to failure at a constant displacement rate on a material testing machine. RESULTS: Group 4 showed lowest load-to-failure result with 155.7 +/- 31.1 N compared to group 1 (293.4 +/- 16.1 N) and group 2 (397.7 +/- 7.4 N) (P < 0.001). Stiffness was highest in group 2 (162 +/- 7.3 N/mm) and lowest in group 4 (84.4 +/- 19.9 mm) (P < 0.001). In group 4, the main cause of failure was due to the suture cutting through the tendon (n = 6), a failure case observed in only n = 1 specimen in group 2 (P < 0.001). CONCLUSIONS: A double-row technique combined with arthroscopic Mason-Allen/horizontal mattress stitches provides high initial failure strength and may minimize the risk of the polyethylene sutures cutting through the tendon in rotator cuff repair when a single load force is used.

Asunto(s)

Fuerza Compresiva , Procedimientos Ortopédicos/métodos , Manguito de los Rotadores/cirugía , Técnicas de Sutura , Animales , Fenómenos Biomecánicos , Análisis de Falla de Equipo , Modelos Animales , Procedimientos Ortopédicos/instrumentación , Distribución Aleatoria , Factores de Riesgo , Manguito de los Rotadores/fisiología , Ovinos , Articulación del Hombro/cirugía , Estrés Mecánico , Anclas para Sutura , Soporte de Peso

RESUMEN

In order to describe the arthroscopic presence of the double bundle structure and to evaluate the value of different portals in knee arthroscopy, we assessed the AM and PL bundle anatomy. We prospectively examined the knees of 60 patients undergoing arthroscopic surgery for pathology unrelated to the ACL. Arthroscopy was performed in a two portal technique using an anterolateral (ALP) and an anteromedial (AMP) portal. With the arthroscope in the ALP, we could distinguish an AM and PL bundle in 28%. Switching the arthroscope to the AMP, differentiation of the bundles was possible in 67%. In all remaining cases visualization of the PL bundle was possible after retraction of the AM bundle. Use of AMP increased visualization of the PL bundle. It seems reasonable to perform arthroscopy for ACL reconstruction with the arthroscope in the AMP and to establish an additional medial working portal to increase the visualization of the femoral ACL insertion sites for optimal femoral tunnel placement.

Asunto(s)

Ligamento Cruzado Anterior/anatomía & histología , Artroscopía/métodos , Adolescente , Adulto , Ligamento Cruzado Anterior/fisiología , Antropometría , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Adulto Joven

RESUMEN

The aim of the study was to evaluate the time zero contact pressure over a defined rotator cuff footprint using different repair and stitch techniques in an established sheep model. Forty fresh-frozen sheep shoulders were randomly assigned to five repair groups: single-row repair using simple stitches (SRA-s), single-row repair using horizontal mattress stitches (SRA-m), and single-row repair using arthroscopic Mason-Allen stitches (SRA-ama). Double-row repair was either performed with a combination of simple and horizontal mattress stitches (DRA-sm) or with arthroscopic Mason-Allen/horizontal mattress stitches (DRA-amam). Investigations were performed using a pressure-sensitive film system. The average contact pressure and pressure pattern were measured for each group. Contact pressure was lowest in SRA-m followed by SRA-s. SRA-ama showed highest contact pressure of all single-row treatment groups (P < 0.05). DRA-amam presented the highest overall contact pressure (P < 0.05), whereas DRA-sm exerted contact pressure equal to that of SRA-ama. Both double-row techniques showed the most expanded pressure pattern. Average contact pressures for the more complex single- and double-row techniques utilizing arthroscopic Mason-Allen stitches were greater than were those of the repair techniques utilizing simple and horizontal mattress stitches. However, the contact pattern between the anchors could be increased by using the double-row technique, resulting in more footprint coverage compared to patterns utilizing the single-row techniques. These results support the use of the more complex arthroscopic Mason-Allen stitches and may improve the environment for healing of the repaired rotator cuff tendon.

Asunto(s)

Manguito de los Rotadores/cirugía , Anclas para Sutura , Técnicas de Sutura , Tenodesis/métodos , Resistencia a la Tracción , Animales , Fenómenos Biomecánicos , Lesiones del Manguito de los Rotadores , Ovinos

RESUMEN

OBJECTIVE: Statins, such as atorvastatin (ATV), are 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors known to exert lipid-lowering but also anti-inflammatory, effects. In this study, we analysed the in vitro effects of ATV on peripheral blood mononuclear cells (PBMCs) and fibroblast-like synoviocytes (FLS) in rheumatoid arthritis (RA), a chronic inflammatory joint disease. METHODS: PBMCs isolated from 25 RA patients and 20 healthy blood donors were stimulated in vitro with 0.1 microM ATV for 24 h. PBMC cultures were analysed for cell surface markers to characterize T-cell subtypes (CD4, CD8, CD69, HLA-DR) by flow cytometry and for T helper cell type 1 (Th1) and type 2 (Th2) cytokines [interferon-gamma (IFN-gamma), interleukin-4 (IL-4), IL-10] in culture supernatants by enzyme-linked immunosorbent assay (ELISA). Furthermore, RNA isolated from ATV-stimulated RA-FLS pre- and post-ATV stimulation was analysed by microarray and quantitative reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Flow cytometric analysis of T-cell subsets revealed no significant differences for CD4, CD8, CD69, and HLA-DR surface marker expression of PBMCs in RA patients and healthy controls after ATV stimulation. However, the proportion of IFN-gamma expressing CD4+ T cells and the IFN-gamma cytokine concentrations in culture supernatants were significantly reduced in T-cell cultures from RA patients. In ATV-stimulated FLS a significant downregulation of proinflammatory cytokine (IL-6) and chemokine (IL-8) expression was detected (p<0.001). CONCLUSIONS: Our study demonstrates a marked in vitro anti-inflammatory activity of ATV in RA including a systemic effect on a pathogenic CD4+ T-cell population (Th1) and a local effect on FLS. These findings may provide a scientific rationale for statins as add-on therapy in RA.

Asunto(s)

Artritis Reumatoide/sangre , Fibroblastos/efectos de los fármacos , Ácidos Heptanoicos/farmacología , Leucocitos Mononucleares/efectos de los fármacos , Pirroles/farmacología , Adulto , Anciano , Antígenos CD/inmunología , Antígenos CD/metabolismo , Antígenos de Diferenciación de Linfocitos T/inmunología , Antígenos de Diferenciación de Linfocitos T/metabolismo , Artritis Reumatoide/tratamiento farmacológico , Artritis Reumatoide/inmunología , Atorvastatina , Biomarcadores/sangre , Linfocitos T CD4-Positivos/efectos de los fármacos , Linfocitos T CD4-Positivos/inmunología , Antígenos CD8/inmunología , Antígenos CD8/metabolismo , Estudios de Casos y Controles , Células Cultivadas , Ensayo de Inmunoadsorción Enzimática , Femenino , Fibroblastos/citología , Citometría de Flujo , Antígenos HLA-DR/inmunología , Antígenos HLA-DR/metabolismo , Humanos , Interleucina-6/inmunología , Interleucina-6/metabolismo , Lectinas Tipo C/inmunología , Lectinas Tipo C/metabolismo , Leucocitos Mononucleares/citología , Masculino , Persona de Mediana Edad , Probabilidad , Valores de Referencia , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Membrana Sinovial/citología , Subgrupos de Linfocitos T/efectos de los fármacos , Subgrupos de Linfocitos T/metabolismo , Adulto Joven

RESUMEN

Our objective was to evaluate the cell biology and biomechanical aspects of the healing process after two different techniques in open rotator cuff surgery - double-loaded bio-absorbable suture anchors combined with so-called arthroscopic Mason-Allen stitches (AAMA) and a trans-osseous suture technique combined with traditional modified Mason-Allen stitches (SMMA). Thirty-six mature sheep were randomized into two repair groups. After 6, 12, or 26 weeks, evaluation of the reinsertion site of the infraspinatus tendon was performed. The mechanical load-to-failure and stiffness results did not indicate a significant difference between the two groups. After 26 weeks, fibrocartilage was sparse in the AAMA group, whereas the SMMA group showed the most pronounced amount of fibrocartilage. We found no ultrastructural differences in collagen fiber organization between the two groups. The relative expression of collagen type II mRNA in the normal group was 1.11. For the AAMA group, 6 weeks after surgery, the relative expression was 55.47, whereas for the SMMA group it was 1.90. This in vivo study showed that the AAMA group exhibited a tendon-to-bone healing process more favorable in its cell biology than that of the traditional SMMA technique. Therefore, the AAMA technique might also be more appropriate for arthroscopic repair.

Asunto(s)

Biología Celular , Manguito de los Rotadores/cirugía , Procedimientos Quirúrgicos Operativos/rehabilitación , Animales , Fenómenos Biomecánicos/fisiología , Colágeno/genética , Colágeno/ultraestructura , Femenino , ARN Mensajero/metabolismo , Distribución Aleatoria , Ovinos , Técnicas de Sutura , Soporte de Peso/fisiología , Cicatrización de Heridas/fisiología

RESUMEN

The aim of the study was to evaluate the time zero mechanical properties of single- versus double-row configuration for rotator cuff repair in an animal model with consideration of the stitch technique and suture material. Thirty-two fresh-frozen sheep shoulders were randomly assigned to four repair groups: suture anchor single-row repair coupled with (1) braided, nonabsorbable polyester suture sized USP No. 2 (SRAE) or (2) braided polyblend polyethylene suture sized No. 2 (SRAH). The double-row repair was coupled with (3) USP No. 2 (DRAE) or (4) braided polyblend polyethylene suture No. 2 (DRAH). Arthroscopic Mason-Allen stitches were used (single-row) and combined with medial horizontal mattress stitches (double-row). Shoulders were cyclically loaded from 10 to 180 N. Displacement to gap formation of 5- and 10-mm at the repair site, cycles to failure, and the mode of failure were determined. The ultimate tensile strength was verified in specimens that resisted to 3,000 cycles. DRAE and DRAH had a lower frequency of 5- (P = 0.135) and 10-mm gap formation (P = 0.135). All DRAE and DRAH resisted 3,000 cycles while only three SRAE and one SRAH resisted 3,000 cycles (P < 0.001). The ultimate tensile strength in double-row specimens was significantly higher than in others (P < 0.001). There was no significant variation in using different suture material (P > 0.05). Double-row suture anchor repair with arthroscopic Mason-Allen/medial mattress stitches provides initial strength superior to single-row repair with arthroscopic Mason-Allen stitches under isometric cyclic loading as well as under ultimate loading conditions. Our results support the concept of double-row fixation with arthroscopic Mason-Allen/medial mattress stitches in rotator cuff tears with improvement of initial fixation strength and ultimate tensile load. Use of new polyblend polyethylene suture material seems not to increase the initial biomechanical aspects of the repair construct.

Asunto(s)

Lesiones del Manguito de los Rotadores , Manguito de los Rotadores/cirugía , Técnicas de Sutura , Suturas , Animales , Ensayo de Materiales , Modelos Animales , Polietileno , Rotura , Ovinos , Resistencia a la Tracción

RESUMEN

BACKGROUND: The study was aimed to evaluate the validity of clinical, radiological and MRI examination for cartilage defects of the knee compared with arthroscopic finding. METHODS: Seven-hundred seventy-two patients who were suffering from knee pain over more than 3 months were evaluated clinical (grinding-sign) and with radiography and magnetic resonance imaging (MRI) and subsequent arthroscopy. RESULTS: The grinding sign had a sensitivity of 0.39. The association of a positive grinding test with high grade cartilage defects was significant (p<0.000). In 97.4% an intact chondral surface correlated with a normal radiological finding. Subchondral sclerosis, exophytes and a joint space narrowing was significantly associated with high grade cartilage defects (p<0.000). The accuracy of MRI was 59.5%. The MRI resulted in an overestimation in 36.6% and an underestimation in 3.9%. False-positive results were significant more often assessed in low-grade cartilage defects (p<0.000). CONCLUSIONS: Clinical signs, x-ray imaging and MRI correlate with arthroscopic findings in cases of deep cartilage lesions. In intact or low-grade degenerated cartilage often results an overestimating of these findings.

Asunto(s)

Artrografía/métodos , Artroscopía/métodos , Enfermedades de los Cartílagos/diagnóstico , Fracturas del Cartílago/diagnóstico , Articulación de la Rodilla/diagnóstico por imagen , Articulación de la Rodilla/patología , Imagen por Resonancia Magnética/métodos , Adolescente , Adulto , Anciano , Femenino , Humanos , Traumatismos de la Rodilla/diagnóstico , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad

RESUMEN

In traditional anterior cruciate ligament reconstruction, there is a subset of patients complaining of knee instability, especially rotational instability, and athletes not able to return to their preinjury level of sports activity. Currently, controversy exists over the usefulness of the double bundle technique (DBT) in addressing these problems. In order to evaluate the DBT, we completed a literature review from 1969 to February 2006 focusing on anatomy, magnetic resonance imaging, graft incorporation, biomechanics, kinematics, surgical techniques, complications and outcome. The DBT is not a standardized technique, which makes it difficult to compare results. Cadaver studies have proven biomechanical advantages with respect to ap-stability, but assessing the rotational stability remains difficult. There is a lack of available outcome studies with sufficient follow-up to demonstrate the potential advantages of DBT. The theoretical advantages of DBT require careful evaluation with outcome, biomechanical and kinematic studies. In addition, studies are needed to address issues such as graft incorporation and complications. An advantage offered by DBT is the possibility to identify rupture patterns that can lead to surgical preservation of an intact and augmentation of an injured bundle. The approach of augmentating a single bundle technique reconstruction with adequate anterior-posterior but poor rotational stability is promising.

Asunto(s)

Lesiones del Ligamento Cruzado Anterior , Ligamento Cruzado Anterior/cirugía , Inestabilidad de la Articulación/cirugía , Traumatismos de la Rodilla/cirugía , Procedimientos Ortopédicos/métodos , Procedimientos de Cirugía Plástica/métodos , Fenómenos Biomecánicos , Humanos , Inestabilidad de la Articulación/fisiopatología , Traumatismos de la Rodilla/fisiopatología , Rotación