Tibial tray cementation is not necessary for knee revision with titanium metaphyseal sleeves: a mid-term prospective study in AORI 2B defects.

PURPOSE: Metaphyseal fixation with porous titanium sleeves in revision knee surgery provides mechanical support to the implant, promotes biological fixation, and has shown satisfactory short- and mid-term results. Cement is commonly used to fix the tibial tray to the epiphyseal area. The objective of this study is to determine whether cement should be used to achieve fixation of the tibial tray with the hypothesis that metaphyseal sleeves would provide enough axial and rotational stability making cementation unnecessary. MATERIAL AND METHODS: Prospective study of 60 patients undergoing knee replacement surgery with metaphyseal sleeves in type 2B defects in femur and tibia. Patients were divided into two groups according to the use of cement on the tibial component. Analysis included the American Knee Society Score (KSS) knee and functional scales, the Western Ontario and McMaster Universities (WOMAC) index, the Short Form 12 (SF-12) health survey, and radiographic assessment with a maximum follow-up of 5 years. RESULTS: No statistically significant differences were found between the two groups in any of the parameters assessed. CONCLUSION: Metaphyseal sleeves showed a 100% survivorship at five years of followup. There were no differences in clinical and radiographic outcomes at five years of follow-up depending on whether or not cement was used for tibial platform fixation. Cementation of the tibial tray would therefore not be required to achieve satisfactory mid-term results. LEVEL OF EVIDENCE: Level II: prospective cohort study. Therapeutic.

ZnO-mesoporous glass scaffolds loaded with osteostatin and mesenchymal cells improve bone healing in a rabbit bone defect.

The use of 3D scaffolds based on mesoporous bioactive glasses (MBG) enhanced with therapeutic ions, biomolecules and cells is emerging as a strategy to improve bone healing. In this paper, the osteogenic capability of ZnO-enriched MBG scaffolds loaded or not with osteostatin (OST) and human mesenchymal stem cells (MSC) was evaluated after implantation in New Zealand rabbits. Cylindrical meso-macroporous scaffolds with composition (mol %) 82.2SiO2-10.3CaO-3.3P2O5-4.2ZnO (4ZN) were obtained by rapid prototyping and then, coated with gelatin for easy handling and potentiating the release of inorganic ions and OST. Bone defects (7.5 mm diameter, 12 mm depth) were drilled in the distal femoral epiphysis and filled with 4ZN, 4ZN + MSC, 4ZN + OST or 4ZN + MSC + OST materials to evaluate and compare their osteogenic features. Rabbits were sacrificed at 3 months extracting the distal third of bone specimens for necropsy, histological, and microtomography (µCT) evaluations. Systems investigated exhibited bone regeneration capability. Thus, trabecular bone volume density (BV/TV) values obtained from µCT showed that the good bone healing capability of 4ZN was significantly improved by the scaffolds coated with OST and MSC. Our findings in vivo suggest the interest of these MBG complete systems to improve bone repair in the clinical practice.

Results measured by means of a motion capture system in proximal humerus fractures treated by osteosynthesis with locking plate. / Resultados medidos con captura de movimiento en las fracturas de húmero proximal tratadas mediante osteosíntesis con placa bloqueada.

OBJECTIVE: To evaluate the results after locking plate internal fixation of proximal humerus fractures by means of a motion capture system, and functional scales. MATERIAL AND METHOD: Retrospective study of a cohort of 47 elderly patients undergoing surgery from January 2010 to December 2014. After a minimum follow-up of two years, two functional scales (Constant-Murley and Quick DASH), and a quality of life scale (EQ-5D) were used for clinical evaluation. For objective evaluation of the range of motion a kinematic marker-free analysis with cameras was performed. RESULTS: The average age was 74.85 years. Average functional scores were: Constant-Murley 70.06 points, Quick DASH 35.74 points and EQ-5D 6.79 points. The average range of motion was: flexion, 111.49°; extension: 24.13°; abduction: 109.40°; adduction: 15.13°; external rotation: 38.96°, and internal rotation: 49.28°. Correlation was found between the two functional scales, between them and the EQ-5D, and between range of motion and functional scales (except for external rotation) as well as between range of motion and EQ-5D (except for flexion and external rotation). CONCLUSION: Locking plate osteosynthesis in proximal humerus fragility fractures achieved good functional and quality of life scores. Motion capture systems can be a useful tool for the functional assessment of shoulder pathology allowing an objective evaluation of range of motion.