Aloinjerto de matriz ósea descalcificada versus injerto autólogo en la reparación de defectos óseos segmentarios masivos. : Estudio experimental

Se compara la capacidad regenerativa del aloinjerto de matriz ósea descalcificada con el tradicional injerto óseo autólogo en el tratamiento de defectos osteoperiósticos de 4-5 cm, de longitud provocados experimentalment e a nivel diafisario en fémur ovino. Para este experimento, se emplearon 18 corderos de raza churra esquelé- ticament e maduros. En 8 animales, la reconstrucción del defecto diafisario se intentó mediant e el aport e aloinjerto fragmentado de matriz óse a descalcificada. En otros 6 animales, el defecto se rellenó con injerto corticoesponjoso autólogo, también fragmentado. La estabilización ósea se realizó por medio de un fijador externo. Tras efectuar estudio s radiológicos e histológicos, los resultados fueron comparado s con un grupo control de 4 animales con el mismo defecto óseo femoral, en los que no se efectuó ningún tipo de reconstrucción ósea. El injerto autólogo se mostró más eficaz que el aloinjerto de matriz ósea descalcificada para la reparación de defectos óseos segmentarios masivos. Sólo en 1 de los animale s tratados con aloinjertos de matriz ósea se observó una actividad osteogénica que condujo a la reparación y consolidación del defecto. Por el contrario, no se observó ningún fracaso en la incorporación y consolidación de los injertos autólogos en los animales que completaron los 4 mese s de estudio.The regenerative capacity of decalcified allogenic matrix was compared with that of autologous bone graft for treatment of osteoperiosteal defects, 4-5 cm in length, experimentally induced in the sheep femoral diaphysis. Eighteen skeletally matur e shee p wer e use d in this investigation. In 8 animals, the reconstructio n of the diaphyseal defect wa s performed using small fragments of decalcified allogeni c bone matrix. In othe r 6 animals, the defect wa s refilled with corticoespongious autologous bone graft in chips. Bone stabilization was achieved by means of an external fixator. After radiologic and histologic assessments, the results wer e compared with a control group including 4 animals with the same diaphyseal defect but without any attempt of reconstruction. Autologous bone graft was found to be more efficient than decalcified allogenic bone matrix for treatment of large segmental bone defects. An osteogeni c activity leading to the complete repair and consolidation of the defect wa s only detected in 1 of the animals treated with allogenic bone matrix. On the contrary, no failures in the incorporation and consolidation of grafts wer e observed in thos e animals treated with autologous bone chips

Bone regeneration during distraction osteogenesis

Bone has the capacity to regenerate in response to injury. During distraction osteogenesis, the renewal of bone is enhanced by gradual stretching of the soft connec- tive tissues in the gap area between two separated bone segments. This procedure has received much clinical atten- tion as a way to correct congenital growth retardation of bone tissue or to generate bone to fill skeletal defects. The process of bone regeneration involves a complex system of biological changes whereby mechanical stress is converted into a cascade of signals that activate cellular behavior resulting in (enhanced) formation of bone. Over the last decade, significant progress has been made in understand- ing the bone regeneration process during distraction osteo- genesis. The mechanical and biological factors that are important for the success of the distraction treatment have been partially characterized and are discussed in this review

Outcomes after perioperative SARS-CoV-2 infection in patients with proximal femoral fractures: an international cohort study

Objectives Studies have demonstrated high rates of mortality in people with proximal femoral fracture and SARS-CoV-2, but there is limited published data on the factors that influence mortality for clinicians to make informed treatment decisions. This study aims to report the 30-day mortality associated with perioperative infection of patients undergoing surgery for proximal femoral fractures and to examine the factors that influence mortality in a multivariate analysis. Setting Prospective, international, multicentre, observational cohort study. Participants Patients undergoing any operation for a proximal femoral fracture from 1 February to 30 April 2020 and with perioperative SARS-CoV-2 infection (either 7 days prior or 30-day postoperative). Primary outcome 30-day mortality. Multivariate modelling was performed to identify factors associated with 30-day mortality. Results This study reports included 1063 patients from 174 hospitals in 19 countries. Overall 30-day mortality was 29.4% (313/1063). In an adjusted model, 30-day mortality was associated with male gender (OR 2.29, 95% CI 1.68 to 3.13, p80 years (OR 1.60, 95% CI 1.1 to 2.31, p=0.013), preoperative diagnosis of dementia (OR 1.57, 95% CI 1.15 to 2.16, p=0.005), kidney disease (OR 1.73, 95% CI 1.18 to 2.55, p=0.005) and congestive heart failure (OR 1.62, 95% CI 1.06 to 2.48, p=0.025). Mortality at 30 days was lower in patients with a preoperative diagnosis of SARS-CoV-2 (OR 0.6, 95% CI 0.6 (0.42 to 0.85), p=0.004). There was no difference in mortality in patients with an increase to delay in surgery (p=0.220) or type of anaesthetic given (p=0.787). Conclusions Patients undergoing surgery for a proximal femoral fracture with a perioperative infection of SARS-CoV-2 have a high rate of mortality. This study would support the need for providing these patients with individualised medical and anaesthetic care, including medical optimisation before theatre. Careful preoperative counselling is needed for those with a proximal femoral fracture and SARS-CoV-2, especially those in the highest risk groups. Trial registration number NCT0432364