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1.
J Shoulder Elbow Surg ; 31(8): 1729-1737, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35151882

RESUMEN

BACKGROUND: Glenoid bone loss in anatomic total shoulder arthroplasty (aTSA) remains a controversial and challenging clinical problem. Previous studies have shown high rates of glenoid loosening for aTSA in shoulders with retroversion, posterior bone loss, and posterior humeral head subluxation. This study is the first to present minimum 2-year follow-up data of an all-polyethylene, biconvex augmented anatomic glenoid component for correction of glenoid retroversion and posterior humeral head subluxation. METHODS: This study is a multicenter, retrospective review of prospectively collected data on consecutive patients from 7 global clinical sites. All patients underwent aTSA using the biconvex posterior augmented glenoid (PAG). Inclusion criteria were preoperative computed tomographic (CT) scan, minimum 2 years since surgery, preoperative and minimum 2-year postoperative range of motion examination, and patient-reported outcome measures (PROMs). Glenoid classification, glenoid retroversion, and posterior humeral head subluxation were measured from preoperative CT and radiography and postoperative radiography. Statistical comparisons between pre- and postoperative values were performed with a paired t test. RESULTS: Eighty-six of 110 consecutive patients during the study period (78% follow-up) met the inclusion criteria and were included in our analysis. Mean follow-up was 35 ± 10 months, with a mean age of 68 ± 8 years (range 48-85). Range of motion statistically improved in all planes from pre- to postoperation. Mean visual analog scale score improved from 5.2 preoperation to 0.7 postoperation, Single Assessment Numeric Evaluation score from 43.2 to 89.5, Constant score from 41.8 to 76.9, and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form score from 49.8 to 86.7 (all P < .0001). Mean glenoid retroversion improved from 19.3° to 7.4° (P < .0001). Posterior subluxation improved from 69.1% to 53.5% and posterior decentering improved from 5.8% to -3.0% (P < .0001). There was 1 patient with both a prosthetic joint infection and radiographic glenoid loosening that required revision. Seventy-nine of 86 patients had a Lazarus score of 0 (no radiolucency seen about peg or keel) at final follow-up. CONCLUSIONS: This study shows that at minimum 2-year follow-up, a posterior-augmented all-polyethylene glenoid can correct glenoid retroversion and posterior humeral head subluxation. Clinically, there was significant improvement in both range of motion and PROMs.


Asunto(s)
Artroplastía de Reemplazo de Hombro , Cavidad Glenoidea , Luxaciones Articulares , Osteoartritis , Articulación del Hombro , Anciano , Anciano de 80 o más Años , Estudios de Seguimiento , Cavidad Glenoidea/diagnóstico por imagen , Cavidad Glenoidea/cirugía , Humanos , Luxaciones Articulares/cirugía , Persona de Mediana Edad , Osteoartritis/diagnóstico por imagen , Osteoartritis/cirugía , Polietileno , Rango del Movimiento Articular , Estudios Retrospectivos , Articulación del Hombro/diagnóstico por imagen , Articulación del Hombro/cirugía , Resultado del Tratamiento
2.
J Shoulder Elbow Surg ; 29(10): e386-e393, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32951645

RESUMEN

BACKGROUND: Structural bone graft for reconstruction of glenoid bone stock is often necessary in the setting of revision shoulder arthroplasty. This study introduces a new structural autograft technique using the distal clavicle for treatment of glenoid bone loss in the setting of revision shoulder arthroplasty. METHODS: This is a retrospective, single-surgeon study of patients with significant glenoid bone loss requiring revision shoulder arthroplasty with autologous distal clavicle bone grafting to the glenoid. Twenty patients with failed shoulder arthroplasty who underwent revisions of their glenoid components between 2015 and 2019 were retrospectively identified. Sixteen patients were available with follow-up of greater than 1 year. Patient records and radiographs were reviewed for intraoperative and postoperative complications. Preoperative and postoperative function were evaluated by physical examination and patient-reported outcome surveys. RESULTS: There were no observed intraoperative complications relating to the distal clavicle autograft harvest or placement. There were no iatrogenic nerve injuries or intraoperative instability. One of the 16 patients developed postoperative loosening and subsequent failure of the glenoid baseplate, requiring revision. One additional patient demonstrated increased elevation of the coracoclavicular interval postoperatively, likely related to the distal clavicle autograft harvest. At a mean follow-up of 25 months, 15 of 16 glenoid implants remained well fixed (93.4%), with no evidence of infection, or impingement demonstrated radiographically or clinically. Average patient age was 69 years at the time of surgery. Forward elevation improved from 76° to 123° at final follow-up (P = .0002). The American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form score improved from an average of 35.8 to 67.8 at mean follow-up (P = .001). The visual analog scale score improved from an average of 5.9 to 2 at mean follow-up, though not statistically significant (P = .068). There was no significant change in external rotation following surgery (P = .319). CONCLUSION: Osteolysis and bone loss of the glenoid poses a challenging problem in revision shoulder arthroplasty. Distal clavicle autograft augmentation is a viable and reproducible technique to manage structural glenoid defects.


Asunto(s)
Artroplastía de Reemplazo de Hombro , Clavícula/trasplante , Cavidad Glenoidea/cirugía , Reoperación/métodos , Articulación del Hombro/fisiopatología , Anciano , Autoinjertos , Trasplante Óseo/efectos adversos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/etiología , Falla de Prótesis , Radiografía , Rango del Movimiento Articular , Estudios Retrospectivos , Rotación , Articulación del Hombro/diagnóstico por imagen , Resultado del Tratamiento
3.
J Shoulder Elbow Surg ; 25(2): 246-55, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26422526

RESUMEN

BACKGROUND: Glenoid components often cause total shoulder arthroplasty failure. This study examines short-term to midterm radiographic and clinical results of a hybrid glenoid component with 3 cemented peripheral pegs and a central peg, which allows biologic fixation with use of native humeral head autograft. METHODS: In 4 years, 80 glenoid components were implanted during primary total shoulder arthroplasty with at least 2-year follow-up data. Within 12 months, 4 shoulders were revised and excluded from final analyses. Seven patients did not complete their questionnaires. Outcomes data included the American Shoulder and Elbow Surgeons (ASES) questionnaire, Constant score, and satisfaction score. A shoulder and elbow fellowship-trained surgeon, not involved in the care of these patients, analyzed radiographs for radiolucent lines, glenoid seating, and radiodensity in between the flanges of the central peg. RESULTS: Only 1 of 80 shoulders was revised for aseptic glenoid loosening. At final follow-up, 81.6% had a radiolucency grade of 0 or 1. Nearly 90% had a glenoid seating grade of A or B. Grade 2 or 3 bone around the central peg was seen in 88.2%. No statistical association existed between Walch glenoid types and radiolucency grades, bone grades around the central peg, perfect radiolucency grade, seating grade, and grade 3 bone around the central peg. There was significant improvement in mean ASES score, adjusted ASES pain score, Constant score, and satisfaction score as well as in forward flexion, abduction, and external rotation. CONCLUSIONS: The hybrid glenoid can produce stable radiographic and clinical outcomes at short- to medium-term follow-up.


Asunto(s)
Artroplastia de Reemplazo/instrumentación , Prótesis Articulares , Articulación del Hombro/diagnóstico por imagen , Articulación del Hombro/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Artroplastia de Reemplazo/métodos , Femenino , Estudios de Seguimiento , Cavidad Glenoidea/diagnóstico por imagen , Humanos , Cabeza Humeral/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Polietileno , Radiografía , Rango del Movimiento Articular , Reoperación , Estudios Retrospectivos , Articulación del Hombro/fisiopatología , Dolor de Hombro/cirugía , Encuestas y Cuestionarios , Factores de Tiempo , Resultado del Tratamiento
4.
J Shoulder Elbow Surg ; 25(7): 1163-9, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26897311

RESUMEN

BACKGROUND: Humeral loosening is an uncommon etiology for revision shoulder arthroplasty. We aimed to evaluate the radiographic and clinical outcomes of a short-stem press-fit humeral component after primary total shoulder arthroplasty. METHODS: We reviewed our patient database, from January 2008 to December 2011, for primary total shoulder arthroplasties performed with a short-stem press-fit humeral component. Radiographs and clinical outcomes were evaluated in the immediate postoperative period and at the most recent follow-up, with at least 24 months of data for all patients. RESULTS: There were 73 shoulders that met our inclusion criteria, but 4 underwent revision before 2 years' follow-up. Only 1 of these 4 was revised for aseptic humeral loosening. Sixty-nine shoulders had at least 24 months of radiographic follow-up, and 62 had radiographic and clinical follow-up. Of the 69 shoulders, 5 underwent revision for humeral loosening: 1 for aseptic loosening and 4 for infection. Two other shoulders with humeral loosening were asymptomatic, and the patients refused revision surgery. The overall revision rate for humeral loosening was 8.2% (6 of 73 shoulders). Radiolucent zones of any size were seen in 71.0%, with 8.7% of these shoulders identified as having humeral stems at risk of future loosening. Significant improvements were made in most of the measured clinical outcomes. CONCLUSIONS: A high percentage of radiolucency was seen around the short-stem press-fit humeral components evaluated in this study at short-term follow-up. The overall rates of loosening and revision for the humeral implant examined in this study are higher than those noted in other recent studies evaluating press-fit stems. The cause of radiolucency and humeral loosening for this implant is not fully understood.


Asunto(s)
Artroplastía de Reemplazo de Hombro/instrumentación , Húmero/diagnóstico por imagen , Falla de Prótesis , Reoperación , Articulación del Hombro/diagnóstico por imagen , Prótesis de Hombro/efectos adversos , Adulto , Anciano , Anciano de 80 o más Años , Artroplastía de Reemplazo de Hombro/efectos adversos , Femenino , Estudios de Seguimiento , Humanos , Húmero/cirugía , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Falla de Prótesis/etiología , Radiografía , Articulación del Hombro/cirugía , Resultado del Tratamiento
5.
Clin Orthop Relat Res ; 472(6): 1930-5, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24515401

RESUMEN

BACKGROUND: Reliable methods of fixation of soft tissue and bone are of utmost importance in reconstructive shoulder surgery and in many orthopaedic applications. Current methods of securing lesser tuberosity osteotomies performed during shoulder arthroplasty and tuberosity fixation performed during repair of proximal humeral fractures often rely on alternating half hitches or surgeon's knots regardless of the suture configuration used passing through the tissue (eg, Mason-Allen, Krackow). The racking hitch knot in contrast to half hitches allows sequential tightening, even under tension, with minimal risk of knot slippage or premature locking. These knot characteristics allow the surgeon to stepwise improve their reduction before committing and locking a construct, preventing hanging knots or under-tensioned repairs. However, little data exist to support the use the racking hitch knot to guide decision making regarding how to back up the knot or to explain the effect of suture material on security and strength. QUESTIONS/PURPOSES: The objectives of our study were (1) to identify the optimal number of half hitches necessary to maintain knot security for a single knot; (2) to evaluate if a difference exists in the relative behavior of racking hitch knots when tied using different suture materials; and (3) to define the biomechanical differences between the racking hitch and two other knot configurations commonly used in shoulder surgery (Weston and square knots). METHODS: Using an Instron device we tested the effect of adding supplemental half hitches (from one to four) to the racking hitch. Additionally, a selection of commercially available braided nonabsorbable polyethylene sutures and different knot configurations (racking hitch, Weston knot, and square knot) also were tested. Data were compared using ANOVA. RESULTS: Increasing the number of half hitches improved knot performance in peak load testing and cyclic testing, revealing a significant difference between the racking hitch supplemented with one and four half hitches (199.2 N versus 428.8 N, p < 0.05). Force Fiber™ #2 (359.6 N) and FiberWire(®) #2 (302 N) showed increased loads to failure compared with Ethibond Excel™ #2 or Force Fiber™ #3/4, whereas Ethibond Excel™ had the least amount of slippage during cyclic testing (0.09 mm). The racking hitch knot had considerably higher loads to failure (359.6 N) than the Weston (145.2 N) or square (77 N) knots. CONCLUSIONS: The racking hitch knot exhibited significantly higher loads to failure and comparable knot slippage (elongation during cyclic testing) when compared with other commonly used knots. According to the biomechanical data, the addition of four half hitches to supplement the racking hitch and the choice of FiberWire(®) #2 or Force Fiber™ #2 suture resulted in increased knot security. CLINICAL RELEVANCE: This knot adds a tool to the arsenal for surgeons best suited for repairs requiring a high degree of knot security and reliable tissue tensioning.


Asunto(s)
Procedimientos Ortopédicos/instrumentación , Hombro/cirugía , Técnicas de Sutura/instrumentación , Suturas , Artroplastia , Diseño de Equipo , Falla de Equipo , Análisis de Falla de Equipo , Humanos , Ensayo de Materiales , Procedimientos Ortopédicos/métodos , Osteotomía , Procedimientos de Cirugía Plástica , Estrés Mecánico
6.
J Hand Surg Am ; 39(6): 1125-9, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24674615

RESUMEN

PURPOSE: Acute elbow injuries that disrupt the lateral ulnar collateral ligament and result in posterolateral rotatory instability usually require surgical treatment. The 2 technical options reported, direct repair and use of a palmaris longus tendon graft, have usually favored the use of the graft. To balance this emphasis, we report our experience with direct repair of the humeral origin in cases of trauma, whether acute, delayed, or recurrent. It was our hypothesis that because the humeral origin is the point of failure and separation, restoration of this attachment is sufficient to restore stability and durable function without the need for a graft. METHODS: Patients with complete disruption of the posterolateral ligaments of the elbow, who were managed with direct repair to the humeral origin, were included. Patients were separated into an acute treatment group (< 30 d from injury to treatment) and a delayed treatment group (> 30 d). Mayo Elbow Performance Scores and postoperative range of motion were collected from patient records. RESULTS: A total of 34 patients were included with a mean follow-up of 42 months. No difference was seen in Mayo Elbow Performance Scores between acute (mean, 90) or delayed treatment (mean, 89) of the lateral ulnar collateral ligament tear. No difference was seen in final elbow flexion or extension. Two patients in the acute group had failure of the direct repair requiring intervention. In the delayed group, no patients had recurrent instability. CONCLUSIONS: No significant difference in clinical outcome or range of motion was observed after direct repair of traumatic tears of the lateral ulnar collateral ligament tear between acute and delayed treatment cohorts. Despite complete disruption of the posterolateral ligaments, direct repair of the torn ligament to its humeral origin was effective without supplemental tendon graft reconstruction irrespective of interval from injury to repair, mechanism of injury, or associated fractures. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.


Asunto(s)
Ligamentos Colaterales/cirugía , Articulación del Codo/cirugía , Inestabilidad de la Articulación/cirugía , Enfermedad Aguda , Adulto , Enfermedad Crónica , Ligamentos Colaterales/lesiones , Femenino , Estudios de Seguimiento , Humanos , Húmero/cirugía , Masculino , Persona de Mediana Edad , Rango del Movimiento Articular/fisiología , Estudios Retrospectivos , Resultado del Tratamiento
7.
J Hand Surg Am ; 38(9): 1746-52.e1-3, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23831364

RESUMEN

PURPOSE: To determine the incidence of elbow contracture requiring release after surgically treated elbow trauma and to identify patient, injury, and treatment factors that may predict contracture development. METHODS: The New York Statewide Planning and Research Cooperative System database identified 32,708 patients who were surgically treated for elbow trauma from 1997 to 2009. The database identified 270 of those patients who underwent subsequent contracture release. The median time from index fracture procedure to contracture release was 31 weeks. RESULTS: Patients requiring a contracture release were younger (43 vs 56 y) and more commonly male (57%). Injuries classified as severe were more common in the contracture group (11% vs 5%), as were open fractures (17% vs 11%). A multivariate regression analysis revealed that patients with burns were 16 times more likely to require surgical contracture release, and the use of internal fixation to treat the fracture was protective against contracture development. CONCLUSIONS: The incidence of elbow contractures treated with release after surgically treated elbow trauma was low but increased with the severity of the initial trauma.


Asunto(s)
Contractura/epidemiología , Contractura/cirugía , Lesiones de Codo , Articulación del Codo/cirugía , Fijación Interna de Fracturas , Luxaciones Articulares/cirugía , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Incidencia , Fracturas Intraarticulares/cirugía , Masculino , Persona de Mediana Edad , New York , Adulto Joven
8.
J Shoulder Elbow Surg ; 22(1): 81-7, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23237692

RESUMEN

BACKGROUND: Safely permitting early range of motion after a destabilizing injury to the elbow is believed to optimize return of function. However, the range-of-motion exercises must be balanced against the risk of re-dislocation or subluxation. The goal of this study was to describe the position of the upper limb that permitted the greatest motion while minimizing the risk of re-dislocation or subluxation. METHODS: Seven cadaveric elbows were affixed with a 3-dimensional motion capture system. Ulnohumeral distraction was recorded at flexion angles from 10° to 90° for intact, approach only (sham procedure), and LCL-sectioned. Ulnohumeral separation was recorded in 3 distinct positions of the upper limb that are frequently used in a clinical setting: 1) trunk seated upright with arm at the side; 2) trunk seated upright with elbow in hinged-brace; and 3) trunk supine with shoulder flexed and internally rotated - "gravity-assisted overhead motion" protocol. RESULTS: A significant ulnohumeral distraction difference was found between the supine and the upright protocols. Upon direct comparison, 104% more displacement occurred across the ulnohumeral joint in the upright LCL-sectioned condition compared to the supine LCL-sectioned condition (P = .001). The greatest ulnohumeral distraction occurred in the seated upright range of motion with a hinged elbow brace (range, 2.5-5.6 mm). CONCLUSION: The overhead motion protocol is a safe protocol for unstable elbows. The supine position results in the least amount of ulnohumeral distraction across flexion angles from 10° to 90°. The upright protocols, especially with the hinged elbow brace, exhibited ulnohumeral distraction that may result in dislocation.


Asunto(s)
Lesiones de Codo , Gravitación , Luxaciones Articulares/etiología , Inestabilidad de la Articulación/etiología , Anciano , Anciano de 80 o más Años , Cadáver , Femenino , Humanos , Masculino , Persona de Mediana Edad , Rango del Movimiento Articular
10.
JSES Rev Rep Tech ; 1(4): 408-413, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37588715

RESUMEN

Purpose: The purpose of this study was to report results of elbow hemiarthroplasty for comminuted, intra-articular distal humerus fractures in low-demand elderly female patients. Methods: This is a retrospective case series of eight patients who underwent elbow hemiarthroplasty for comminuted, intra-articular distal humerus fractures between 2015 and 2019. Patients were considered for the procedure if the humeral fractures were deemed nonreconstructable by open reduction internal fixation. Patients were excluded if the extensor mechanism was not intact, evidence of significant ulnohumeral osteoarthritis, or a fracture to the proximal radius or ulna. A "triceps-on" approach was used in all cases. Appropriate sizing of the spool and length of the implant were determined by intraoperative fluoroscopy. Both ulnar collateral ligament and the lateral ulnar collateral ligaments were repaired through the central spool after final placement of the implant. Postoperative radiographs, clinical data, and the Mayo Elbow Performance Score were used to assess elbow pain and function. Results: Seven patients were included in final analysis. One patient was excluded from final analysis after sustaining a ground-level elbow dislocation at 13 weeks postoperatively, which subsequently revised to total elbow arthroplasty. The average age at the final follow-up was 72.1 years and duration of follow-up was 29.9 months (range 11.4-58.8 months). Average elbow range of motion was 21° ± 15° extension, 135° ± 9° flexion, 87° ± 5° pronation and 84° ± 8° supination. The average Mayo Elbow Performance Score was 88.3 (range 85-95; or "good" to "excellent") at the final follow-up. Postoperative ulnar neuropathy was reported by one patient at the first postoperative visit. This was followed up clinically and evaluation at 24 months revealed mild residual sensory deficits and adequate strength and motor function. Conclusion: Elbow hemiarthroplasty using the humeral component of the total elbow arthroplasty is an option for treatment of isolated, comminuted distal humerus fractures in select patient populations. The ideal candidates are elderly, low-demand, and able to adhere to postoperative activity and weight-bearing restrictions. Overall patient satisfaction with off-label use of humeral component of commercially available total elbow implants in the United States is promising, yet development of a more anatomic spool is warranted to further optimize outcomes intraoperatively. Some advantages of elbow hemiarthroplasty are a less-demanding operation and avoids complications associated with linked design including polyethylene wear, periprosthetic fracture, or implant loosening. Limitations of this study include small sample size and retrospective nature of the study.

11.
Foot Ankle Int ; 29(10): 1009-14, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18851817

RESUMEN

BACKGROUND: Oblique shortening osteotomy (Weil) can address lesser MP pathology but can have a high rate of complications. The purpose of this study was to review the results of a modification of the Weil osteotomy, the segmental resection metatarsal osteotomy. MATERIALS AND METHODS: Between 2004 and 2006, 48 patients underwent the segmental resection osteotomy with a mean followup of 13 (range, 6 to 26) months. All the patients were evaluated with the American Orthopaedic Foot and Ankle Society (AOFAS) forefoot score and a questionnaire addressing distances they were able to walk, work limitations, sporting activity, and overall satisfaction. RESULTS: The postoperative AOFAS forefoot score was an average of 87.6 (range, 59 to 100; SD, 10.97) and the overall satisfaction rate was 85.4%. The complication rate was 18.8% for transfer metatarsalgia, 27.1% for floating toes, 35.4% for toe weakness, 14.6% for infection, and 10.4% for wound healing problems. CONCLUSIONS: Despite the complications, the patients who underwent segmental osteotomy were satisfied with the outcome for lesser MTP joint pain and deformity. This is a preliminary study with significant refinement of the operative method as detailed in the surgical technique section. Further followup will elucidate whether additional changes are necessary in the surgical technique.


Asunto(s)
Articulación Metatarsofalángica/cirugía , Osteotomía/métodos , Adulto , Anciano , Anciano de 80 o más Años , Artralgia/cirugía , Femenino , Estudios de Seguimiento , Humanos , Deformidades Adquiridas de la Articulación/cirugía , Luxaciones Articulares/cirugía , Masculino , Persona de Mediana Edad , Satisfacción del Paciente , Complicaciones Posoperatorias , Recuperación de la Función , Estudios Retrospectivos , Resultado del Tratamiento
12.
J Orthop Res ; 24(6): 1208-17, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16652339

RESUMEN

The objectives of this study were to analyze simultaneously meniscal and tibiofemoral kinematics in healthy volunteers and anterior cruciate ligament (ACL)-deficient patients under axial load-bearing conditions using magnetic resonance imaging (MRI). Ten healthy volunteers and eight ACL-deficient patients were examined with a high-field, closed MRI system. For each group, both knees were imaged at full extension and partial flexion ( approximately 45 degrees ) with a 125N compressive load applied to the foot. Anteroposterior and medial/lateral femoral and meniscal translations were analyzed following three-dimensional, landmark-matching registration. Interobserver and intraobserver reproducibilities were less than 0.8 mm for femoral translation for image processing and data analysis. The position of the femur relative to the tibia in the ACL-deficient knee was 2.6 mm posterior to that of the contralateral, normal knee at extension. During flexion from 0 degrees to 45 degrees , the femur in ACL-deficient knees translated 4.3 mm anteriorly, whereas no significant translation occurred in uninjured knees. The contact area centroid on the tibia in ACL-deficient knees at extension was posterior to that of uninjured knees. Consequently, significantly less posterior translation of the contact centroid occurred in the medial tibial condyle in ACL-deficient knees during flexion. Meniscal translation, however, was nearly the same in both groups. Axial load-bearing MRI is a noninvasive and reproducible method for evaluating tibiofemoral and meniscal kinematics. The results demonstrated that ACL deficiency led to significant changes in bone kinematics, but negligible changes in the movement of the menisci. These results help explain the increased risk of meniscal tears and osteoarthritis in chronic ACL deficient knees.


Asunto(s)
Fémur/fisiopatología , Articulación de la Rodilla/fisiopatología , Imagen por Resonancia Magnética/métodos , Meniscos Tibiales/fisiopatología , Rango del Movimiento Articular , Tibia/fisiopatología , Adulto , Ligamento Cruzado Anterior/patología , Lesiones del Ligamento Cruzado Anterior , Fenómenos Biomecánicos , Fémur/patología , Humanos , Inestabilidad de la Articulación/patología , Inestabilidad de la Articulación/fisiopatología , Articulación de la Rodilla/patología , Meniscos Tibiales/patología , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Tibia/patología , Soporte de Peso
13.
Curr Rev Musculoskelet Med ; 4(4): 191-9, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21826432

RESUMEN

Management of glenohumeral arthrosis with a total shoulder prosthesis is becoming increasingly common. However, failure of the glenoid component remains one of the most common causes for failure. Our understanding of this problem has evolved greatly since the first implants were placed in the 1970's. However glenoid failure remains a challenging problem to address and manage. This article reviews the current knowledge regarding the glenoid in total shoulder arthroplasty touching on anatomy, component design, implant fixation, causes of implant failure, management of glenoid failure and alternatives to glenoid replacement.

16.
Horm Behav ; 47(3): 336-42, 2005 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15708763

RESUMEN

The African cichlid fish, Astatotilapia burtoni, has a complex social system with a sophisticated social hierarchy that offers unique opportunities to understand how social rank and its physiological substrates relate to behavioral strategies. In A. burtoni, a small fraction of the males are dominant (T, territorial), as distinguished by being large, brightly colored, reproductively active, and aggressively defending territories. In contrast, the majority of males are non-dominant (NT, non-territorial), being smaller, drably colored, sexually immature, and typically schooling with females. The social system is regulated by aggressive interactions between males and behavioral responses to aggression can be direct or displaced with respect to the animal that acts. To determine whether direct and displaced behaviors are differentially exhibited by T and NT males, individuals were shown a video presentation of a dominant male displaying aggressively. Analysis of aggressive acts toward the video display and displaced activity toward a tank mate revealed that T males exhibited more direct behavior (toward the video display), while NT males engaged in more displaced behavior (toward tank mates). Because similar experiments with primates suggest that shifts in behavioral strategies are linked to changes in the stress response (as measured by circulating cortisol levels), we measured cortisol levels of T and NT males following exposure to the aggressive stimulus. Although in some animals subordinate males are reported to have higher cortisol levels, here we show that in A. burtoni the endocrine response to specific situations can vary considerably even among animals of the same status. Interestingly, NT males with intermediate cortisol levels showed more directed behavior while NT males with both high and low cortisol levels showed more displaced. This suggests an optimal physiological stress response in NT males that predisposes them to challenge aggressors perhaps making it more likely for them to ascend in status.


Asunto(s)
Adaptación Psicológica/fisiología , Agresión/fisiología , Cíclidos/fisiología , Jerarquia Social , Estrés Fisiológico/fisiopatología , Enfermedad Aguda , Animales , Femenino , Hidrocortisona/sangre , Masculino , Territorialidad , Testosterona/sangre
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