rhBMP-2 may be an appropriate alternative to autogenous bone graft in both single- and multilevel revision PLF, whereas BMAA may be appropriate as a substitute in single-level revision PLF. The use of BMAA in single-level revisions may be a more cost-effective option than rhBMP-2.

The authors proposed a reliable and reproducible grading system that may be used to investigate spinal kinematics in association with ISLD. The authors' findings illustrated the distribution of ISLD grades. The most severe grade occurred primarily in elderly patients. Mobility decreased in the most severe grade; therefore, the stage of ISLD should be taken into consideration when evaluating spinal stability.

Gorham syndrome is a rare disease that presents as progressive osteolysis, and may affect any part of the skeleton. The pathologic process involves the replacement of normal bone by aggressively expanding but non-neoplastic vascular tissue, resulting in massive osteolysis of the adjacent bone. If the spine and ribs are affected, the subsequent kyphosis and chest wall deformity may cause severe restrictive ventilatory impairment. We report a 34-year-old male with Gorham syndrome presenting as progressive kyphosis, severe back pain, unstable gait, and exertional dyspnea. Pulmonary function testing revealed severe restrictive ventilatory impairment. He underwent spinal surgery but could not be extubated after surgery. Postoperative left lower lung pneumonia and respiratory failure required prolonged mechanical ventilation. After a weaning program of pressure support ventilation and T-piece spontaneous breathing trials, he was successfully weaned from mechanical ventilation.

Bone morphogenetic binding peptide (BBP) is an 18.5 kDa fragment of a bone matrix protein peptide. A rat femoral defect model was used to test the effect of BBP combined with recombinant human bone morphogenetic protein-7 (rhBMP-7) to induced bone healing. Two doses of BBP (500 and 1000 mg) were tested with two doses of rhBMP-7 (2 and 5 mg), and the results were compared with a positive control (10 mg rhBMP-7). Bone healing was evaluated by radiology, manual palpation, microcomputed tomography, and histology. The high dose of 10 mg of rhBMP-7 resulted in a consistent 100% bone union rate and a mature histological appearance on histology, and was used as a positive control. When 1000 mg of BBP was combined with lower doses of BMP-7 (2 mg rhBMP-7 or 5 mg rhBMP-7) significant differences were seen in radiographic scores, manual palpation, and bone volume, when compared to 2 mg rhBMP-7 or 5 mg rhBMP-7 alone. The combination of 1000 mg of BBP and 5 mg rhBMP-7 also achieved 100% fusion rate, induced a larger amount of bone formation, and yielded similar maturity of bone marrow when compared with the high dosage 10 mg rhBMP-7 group. This study demonstrated that when combined together, BBP can enhance the bone healing of rhBMP-7. Improved healing imparted by the addition of BBP may result in lesser amounts of rhBMP-7 needed to achieve union in the clinical setting. ß