ABSTRACT
An intervertebral titanium tumour cage was implanted in a 2-year-old-girl after T11 spondylectomy due to Ewing sarcoma. After 2-years' follow-up without evidence of recurrence, the titanium cage was explanted to correct spinal deformity and to allow normal spinal growth development. Radiological follow-up and surgical exploration at the time of retrieval suggested fusion of the segment. Histologic evaluation, however, demonstrated ingrowth of trabecular bone, but without bridging trabecular bone. The distance between the opposing bone fronts measured 1.5 mm and the viable bone volume (BV/TV) within the cage was 36%. Histologic evaluation demonstrated that bone formation was still an ongoing process in the fusion zone 2 years after implantation.
Subject(s)
Internal Fixators/standards , Sarcoma, Ewing/surgery , Spinal Fusion/instrumentation , Thoracic Vertebrae/surgery , Titanium/therapeutic use , Child, Preschool , Female , Humans , Internal Fixators/trends , Magnetic Resonance Imaging , Osteogenesis/physiology , Postoperative Complications/etiology , Postoperative Complications/physiopathology , Postoperative Complications/prevention & control , Radiography , Spinal Cord Compression/etiology , Spinal Cord Compression/pathology , Spinal Cord Compression/physiopathology , Spinal Fusion/methods , Thoracic Vertebrae/diagnostic imaging , Thoracic Vertebrae/pathology , Titanium/standards , Treatment Failure , Treatment Outcome , Wound Healing/physiologyABSTRACT
We show the use of a dimensionless parameter alpha h, in properly downscaling a parallel-plate flow chamber system for flow stimulation of bone cells under microgravity. The proper experimental regime for exposing cells to predictable levels of dynamic fluid shear stress requires: 1) alpha h < 2, based on the consequent quasi-parabolic form of the velocity profile in this regime, and 2) fo m
