The anterior transoral-transpharyngeal operation to correct ventral irreducible compression of the cervicomedullary junction was utilized in 72 individuals. The patients' ages ranged from 6 to 82 years, and 29 were children. The pathology encountered was primary basilar invagination, rheumatoid irreducible cranial settling, secondary basilar invagination due to migration of odontoid fracture fragments, dystopic os odontoideum, granulation masses, clivus chordoma, osteoblastoma, and chondroma of the atlas. Fifteen patients had associated Chiari malformation with basilar invagination. Fifty-two patients required subsequent atlantoaxial or occipitocervical fusion. Neurological improvement was the rule. There were two deaths within 30 days of surgery: one from myocardial infarction 4 weeks after surgery and one from Gram-negative septicemia of urinary tract origin. There was one pharyngeal wound infection. The ventral transoral approach provides a safe, rapid, and effective means for decompression of the abnormal craniovertebral junction.

Although most patients were referred for cutaneous stigmata evaluation, >50% had neurologic deficit, intradural tumors, or tethered cords. Skin findings identification should initiate prompt radiologic evaluation and neurosurgical intervention with intradural exploration. Timely intervention may preserve or improve neurologic function in these patients.

Demographic data obtained in both groups were comparable. Rib constructs were placed in the following regions: occipitocervical (196 patients), atlantoaxial (35 patients), and subaxial cervical spine (69 patients). Iliac crest grafts were placed in the occipitocervical (28 patients), atlantoaxial (10 patients), and subaxial cervical (14 patients) regions. Fusion occurred in 296 (98.8%) of 300 rib graft and 49 (94.2%) of 52 iliac crest graft constructs (p = 0.056). Graft morbidity was greater with iliac crest than with rib (p < 0.00001). Donor-site morbidity for the rib graft was 3.7% and included pneumonia (eight patients), persistent atelectasis (two patients), and superficial wound dehiscence (one patient). Pneumothorax, intercostal neuralgia, and chronic chest wall pain were not encountered. Iliac crest morbidity occurred in 25.3% of the patients and consisted of chronic donor-site pain (52 patients), wound dehiscence (eight patients), pneumonia (seven patients), meralgia paresthetica (four patients), hematoma requiring evacuation (three patients), and iliac spine fracture (two patients). Even when chronic pain was not considered, morbidity encountered in obtaining iliac crest still exceeded that encountered with rib harvest (p = 0.035). The fusion rate and donor-site morbidity for rib autograft compare favorably with those for iliac crest when used in posterior cervical constructs. To the authors' knowledge, this represents the largest series to date in which the safety and efficacy of using autogeneic bone graft materials in spinal surgery are critically analyzed.

The conclusion was that os odontoideum was associated with an unrecognized fracture in children below the age of 5 with a previously normal odontoid structure as observed in our series. Atlas and axis abnormalities were reviewed in this series. This large database has provided an understanding of the natural history of many entities and allowed treatment protocols to be established that have stood the test of time.