In vivo study of chitosan-natural nano hydroxyapatite scaffolds for bone tissue regeneration.

Significant development has been achieved with bioceramics and biopolymer scaffolds in the construction of artificial bone. In the present study, we have developed and compared chitosan-micro hydroxyapatite (chitosan-mHA) and chitosan-nano hydroxyapatite (chitosan-nHA) scaffolds as bone graft substitutes. The biocompatibility and cell proliferation of the prepared scaffolds were checked with preosteoblast (MC3T3-E1) cells. Total Volume (TV), bone volume (BV), bone surface (BS), trabecular thickness (Tb.Th), trabecular number (Tb.N) and trabecular separation (Tb.Sp) were found to be higher in chitosan-nHA than chitosan-mHA scaffold. Hence, we suggest that chitosan-nHA scaffold could be a promising biomaterial for bone tissue engineering.

Preoperative plan for corrective osteotomy of the hip: a method using picture-editing software.

BACKGROUND: As the Picture Archiving and Communication System (PACS) has been adopted by many health centers for radiographic image storage and analysis, fewer and fewer physicians are using radiographic films and the traditional paper-drawing technique for creating preoperative surgical plans. Therefore, a new technique is required using the digital images in stored PACS. Any new method should not only be easy to perform while accurately reflecting the actual techniques of hip osteotomy, but also it should hopefully not require the purchase of expensive software. METHODS: We developed a method using widely available commercial image-editing software (Adobe Photoshop and Microsoft PowerPoint) that works with preoperative anteroposterior and lateral radiographs in stored PACS. To compare our technique with the traditional paper-drawing approach, we measured the time it took for 5 orthopaedic residents to prepare 1 surgical plan using each technique, for 6 different procedures (3 femoral osteotomy and 3 femoral plus pelvic osteotomy). RESULTS: The new method has been used in planning surgery on 133 hips. For femoral osteotomy, the average time required for the traditional and new techniques was 54 and 49 minutes, respectively; whereas for a combined femoral and pelvic osteotomy, the traditional technique took 71 minutes compared with 63 for the new approach. CONCLUSIONS: The new technique is not only cost effective and easy to learn, but also is more efficient and clearer than the conventional method using hand-made drawings, thus making the surgery itself easier to perform. LEVEL OF EVIDENCE: Level III, therapeutic study.