Factors that influence the complications and outcomes of femoral neck fractures treated by cannulated screw fixation.

To investigate the influence of various factors on the two outcome parameters "procedure - specific complication" (femoral head necrosis, infection, nonunion, femoral neck shortening, screw loosening, implant penetration) and "functional outcome" in patients with displaced and undisplaced femoral neck fracture treated by cannulated screw fixation. All cases of a femoral neck fracture, operated by cannulated screw fixation, in the period from December 2014 to December 2017 were included. The observation period of the included patients was 12 months. Information on their outcome was collected after evaluation of current x-ray images and on request from the responsible further treatment physician. Continuous data were presented as mean value ± standard deviation, categorical data as absolute and relative frequency. The effect of potential factors on endpoints was estimated with a multivariable logistic regression analysis and 95% confidence intervals calculated. The null hypothesis Odds Ratio = 1 was checked by the Wald test. The likelihood ratio test was used to test for deviation from linearity. The mean age of the 56 included patients was 72 years (36 min, 96 max), 44.5% (n = 25) were male and 55.5% (n = 25) female. The femoral neck fractures were classified as follows: Garden I: 73%, Garden II: 16%, Garden III: 11%, Pauwels I: 73%, Pauwels II: 21%, Pauwels III: 5%, 31-B1: 73%, 31-B2: 27%, 31-B3: 0%. The factor patient age showed a statistically significant influence on the outcome parameter procedure-specific complication. None of the remaining factors examined showed a statistically significant influence on both outcome parameters procedure-specific complication and functional outcome. 69% of the patients from age 80 onwards suffered a procedure-specific complication. A rate of 41% procedure-specific complications as an outcome parameter in trauma surgery shows a necessity for improvement. The increasing risk of procedure-specific complications for patients with a femoral neck fracture treated by cannulated screw fixation is associated with rising patient age. A more stable head-perserving operative method or an endoprosthetic procedure should be considered in high-risk patients (≥80 y.o.).

Meniscus reconstruction: today's achievements and premises for the future.

Injuries of the meniscus remain a burden for the development of premature cartilage degeneration and osteoarthritis. This review surveys all treatment options and focuses on the recent development of tissue engineering. Tissue engineering of the meniscus means a successful combination of cells, scaffolds and specific stimuli. Each element of the combination can be subject to variation. Studies investigating the optimum meniscus implant and previous steps in producing these implants are presented in this article. A comprehensive search of the English and German literature was performed in PubMed to retrieve appropriate manuscripts for review. Based on the literatures, autografts and allografts can delay the progress of osteoarthritis for a restricted time period, but several concerns persist. The biomechanical properties of the native meniscus are not copied entirely by the current existing autografts. Congruence, fixation, biocompatibility and potential infection will always remain as limitations for the users of allografts. Long-term results are still not available for meniscus prosthesis and even though it permits fast recovery, several aspects are questionable: bioincompatibility and a lack of cellular adhesion are likely to compromise their long-term fate. Currently, there is no ideal implant generated by means of tissue engineering. However, meniscus tissue engineering is a fast developing field, which promises to develop an implant that mimics histological and biomechanical properties of the native meniscus. At present several cell sources and scaffolds have been used successfully to grow 3-dimensional constructs. In future, optimal implants have to be developed using growth factors, modified scaffolds and stimuli that support cellular proliferation and differentiation to regenerate the native meniscus more closely.

Seeding a human tendon matrix with bone marrow aspirates compared to previously isolated hBMSCs--an in vitro study.

Injuries of tendons and ligaments give rise to significant morbidity. Tissue engineering offers promising treatment concepts such as seeding a scaffold with human bone marrow stem cells (hBMSCs) to create high-quality tendon replacement tissue. HBMSCs are usually isolated and cultured prior to seeding. Studies evaluating if previous isolation is superior to seeding with bone marrow aspirates have not been published yet. The aim of this study was to compare these two seeding methods in terms of cell viability, proliferation and differentiation. HBMSCs were harvested from the iliac crest during routine trauma surgery. In group A the scaffold (human achilles tendons) was seeded with bone marrow aspirates, while in group B hBMSCs were isolated, harvested and then seeded. Constructs were stimulated in perfusion bioreactors according to established protocols. Mean cell proliferation was significantly increased (p< 0.05) on tendons seeded with bone marrow aspirates. Cell viability, the concentration of alkaline phosphatase in the perfused media and the synthesis of procollagen - III - polypeptide (PIIIP) were not significantly different when comparing the two groups. The synthesis of procollagen-I-polypeptide (PIP) was significantly increased on tendons seeded with previously isolated hBMSCs p < 0.05). The results indicate that seeding a human tendon matrix scaffold with bone marrow aspirates may be equal to seeding with previously isolated hBMSCs. This new seeding method could facilitate and speed up the tissue engineering process.