Catastrophic wear in uncemented acetabular cups after Total Hip Arthroplasty. A case series.

INTRODUCTION: Catastrophic wear is a rare outcome following Total Hip Arthroplasty (THA), documented to happen in less than 0.5% of THA. We present 5 cases of revision THA performed successfully on 5 patients presenting Catastrophic wear, following Total Hip Arthroplasty (THA). Specifically, Catastrophic wear cases were selected, emphasizing differential diagnosis, and a revision THA was performed in all of them and resulted in a good long-term outcome. The purpose of this case series is to contribute to the literature in evaluating both the causes of implant failure as well as the outcomes after their revisions. METHODS: We evaluated 5 patients that presented Catastrophic rupture of acetabular implants in a 3-week period in our prosthesis center. RESULTS: The 5 patients were females, the mean age was 56 years (44-65), the mean post-surgery time was 20 years (17-23), 4/5 of the coupling wear was ceramic-polyethylene and only one case was metal-polyethylene; 4/5 had bilateral total hip replacement. In the 5 cases a revision THA was performed, all with a successful outcome. CONCLUSION: Catastrophic failure is an unusual entity; however, when a patient with a prosthesis presents with sudden pain, an immediate image study is indicated, with careful attention to the differential diagnosis, so as to accurately advice receiving a revision THA. The main causes of implant failure are implant duration, volumetric wear and subsequent rupture. Patients with Catastrophic wear and implant rupture, treated with a revision THA, usually have a good long-term outcome.

Human Aging Alters the Spatial Organization between CD34+ Hematopoietic Cells and Adipocytes in Bone Marrow.

Age-related clonal hematopoiesis is a major risk factor for myeloid malignancy and myeloid skewing is a hallmark of aging. However, while it is known that non-cell-autonomous components of the microenvironment can also influence this risk, there have been few studies of how the spatial architecture of human bone marrow (BM) changes with aging. Here, we show that BM adiposity increases with age, which correlates with increased density of maturing myeloid cells and CD34+ hematopoietic stem/progenitor cells (HSPCs) and an increased proportion of HSPCs adjacent to adipocytes. However, NGFR+ bone marrow stromal cell (NGFR+ BMSC) density and distance to HSPCs and vessels remained stable. Interestingly, we found that, upon aging, maturing myeloid cell density increases in hematopoietic areas surrounding adipocytes. We propose that increased adjacency to adipocytes in the BM microenvironment may influence myeloid skewing of aging HSPCs, contributing to age-related risk of myeloid malignancies.

[Prophylaxis of venous thromboembolic disease in high-risk orthopedic surgery]. / Profilaxis de la enfermedad tromboembólica venosa en cirugía ortopédica de alto riesgo.

Venous thromboembolism (VTE) is a worldwide public health problem, with an annual incidence of 1-2 cases/1,000 individuals in the general population and a 1-5% associated mortality. Orthopedic surgery is a major surgical risk factor for VTE, but the problem is more important for patients with hip and knee joint replacement, multiple traumatisms, severe damage to the spine, or large fractures. Thromboprophylaxis is defined as the strategy and actions necessary to diminish the risk of VTE in high-risk orthopedic surgery. Antithrombotics may prevent VTE. At the end of this paper, we describe a proposal of thromboprophylaxis actions for patients requiring high-risk orthopedic surgery, based on the opinion of specialists in Orthopedics and Traumatology who work with high-risk orthopedic surgery patients. A search for evidence about this kind of surgery was performed and a 100-item inquiring instrument was done in order to know the opinions of the participants. Then, recommendations and considerations were built. In conclusion, this document reviews the problem of VTE in high-risk orthopedic surgery patients and describes the position of the Colegio Mexicano de Ortopedia y Traumatología related to VTE prevention in this setting.

Fijación externa no transfictiva en osteotomía tibial alta / Non-transfixing external fixation for proximal tibial osteotomy

Entre mayo de 1992 y noviembre de 1994, se realizaron 236 cirugía para corección de genu varo en el Hospital de Traumatología y Ortopedía ®Lomas Verdes¼, de éstos, se seleccionaron 100 casos para un estudio comparativo prospectivo, tratando a 50 de ellos mediante técnica de Maquet y fijación externa no transfictiva, y 50 mediante fijación externa transfictiva, la deformidad promedio fue de 14.9 grado, el grado de artrosis y el dolor preoperatorio fueron moderados a severos en más de 75 por ciento de los casos, la técnica de la osteotomía fue estandarizada, solamente cambió el método de fijación, el tiempo quirúrgico fue menor con fijación no transfictiva, la infección se presntó en 24 por ciento de fijación transfictiva, la lesión del ciático poplíteo externo fue de 3.7 por ciento en fijación no transfictiva comparada con 13 por ciento de la transfictiva, el tiempo de consolidación fue similar, el dolor disminuyó en 77 por ciento de ambos grupos, la flexión promedio fue mayor en fijación no transfictiva, la corrección del eje mecánico fue similar, la marcha normal es similar, la anormal es mayor en la fijación transfictiva, los resultados globales señalan a la fijación tubular no transfictiva como una alternativa eficaz en sujetos menores de 60 años sin osteoporosis marcada