{'fraction_non_alphanumeric': 0.035015447991761074, 'fraction_numerical': 0.02368692070030896, 'mean_word_length': 5.352941176470588, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Computer-assisted spinal navigation using a percutaneous dynamic reference frame for posterior fusions of the lumbar spine.

We report a 6-year retrospective review of screw placement utilizing a percutaneous dynamic reference frame attached to the posterior superior iliac spine performed by a single orthopedic surgeon. We included all lumbar spine procedures utilizing computer-assisted spinal navigation (StealthStation Navigation System, Medtronic Navigation, Louisville, Colo) performed from 2000 to 2005, with 272 of 289 patients (94.1%) having at least a 4-month follow-up with radiographs. Six hundred seventy-two screws were placed. Following surgery, none of these patients had screw misplacements. One patient (0.4%) had a screw backing out of the pedicle. Eighteen patients (6.6%) had their posterior instrumentation removed. Three had repeat operations but did not have their instrumentation removed. No patient with repeat operations had a screw misplaced.