To identify a value of labelling index beyond which adenomas should be considered invasive and another beyond which cavernous sinus infiltration should be suspected, normality Q-Q plots were obtained: a threshold labelling index of 3.5% for invasive adenomas and of 5% for cavernous sinus infiltrating adenomas was defined, with statistically significant differences (p = 0.02 and p = 0.004, respectively). Conclusions-The Ki-67 labelling index can be considered a useful marker in determining the invasive behaviour of anterior pituitary adenomas. (J Clin Pathol 1999;52:107-111)

Between 1985 and 1995, 33 cases of clinoidal meningioma were surgically treated by pterional approach. In 6 cases, according to the grading scale of Al-Mefty, the lesions were group I, having originated from the lower part of the clinoid; in 22 cases, the lesions were group II, having originated from the upper or lateral part of the clinoid process; and in 5 cases, the lesions were group III since they arose from the optic foramen. Postoperatively, 17 patients showed an improvement, 4 were unchanged, and 6 presented further deficits. Five patients died after surgery: two from pulmonary thromboembolism, one from myocardial infarction, one from hematoma of the operative field, and one from cerebral ischemia after severe vasospasm of the internal carotid artery (unresponsive to treatment). The mean follow-up was 53.7 months (range 12-108 months) and included 19 patients. During this period, there were five recurrences, and three patients underwent resection again and showed no signs of tumor regrowth 1 year later; one patient who did not undergo resection again due to his age and poor general conditions died 3 years after onset of the recurrence; the last patient has so far refused a second operation. The clinical, diagnostic, and therapeutic aspects of this not infrequent pathology are discussed in the light of our experience and the pertinent literature.

Object. The purposes of bone substitutes for anterior cervical fusion (ACF) are immediate biomechanical support and osteointegration of the graft. The authors report their preliminary results in performing ACF in which carbon fiber cages (CFCs) containing coralline hydroxyapatite (HA) are used as bone substitute. Methods. During a 24-month period, anterior microsurgical discectomy was performed in 45 consecutive patients for soft-disc cervical herniation. In all cases ACF was performed using a CFC containing a core of granulated coralline HA. Fifty-seven CFCs were implanted in 33 single-level and 12 two-level procedures. The mean operative time was 83 minutes for one-level and 97 minutes for two-level procedures. The mean hospital stay was 1.51 days, and there were no permanent complications. At a mean follow up of 22.3 months, the pain had decreased or disappeared in all patients, and the patients' satisfaction rate was very high. Good results were also obtained in patients who smoked cigarettes. Patients underwent radiographic evaluation at Day 1, and 1, 3, 6, and 12 months postoperatively. Implant-related complications were not observed and revision surgeries were not performed. Twelve-month cervical x-ray films demonstrated complete fusion in all cases, without evidence of breakage, collapse, pseudarthrosis, subsidence, angular deformity, or protrusion. Signs of pathological absorption and necrosis were not found in contiguous vertebral bodies, and inflammatory reactions were never seen around cages. Conclusions. These preliminary results suggest that implants composed of CFC containing granulated coralline HA are promising bone substitutes to be used in ACF, with a good rate of incorporation and no significant complications.

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OBJECT Spacers placed between the lumbar spinous processes represent a promising surgical treatment alternative for a variety of spinal pathologies. They provide an unloading distractive force to the stenotic motion segment, restoring foraminal height, and have the potential to relieve symptoms of degenerative disc disease. The authors performed a retrospective, multicenter nonrandomized study consisting of 1108 patients to evaluate implant survival and failure modes after the implantation of 8 different interspinous process devices (IPDs). METHODS The medical records of patients who had undergone placement of an IPD were retrospectively evaluated, and demographic information, diagnosis, and preoperative pain levels were recorded. Preoperative and postoperative clinical assessments in the patients were based on the visual analog scale. A minimum of 3 years after IPD placement, information on long-term outcomes was obtained from additional follow-up or from patient medical and radiological records. RESULTS One thousand one hundred eight patients affected by symptomatic 1- or 2-level segmental lumbar spine degenerative disease underwent placement of an IPD. The complication rate was 7.8%. There were 27 fractures of the spinous process and 23 dura mater tears with CSF leakage. The ultimate failure rate requiring additional surgery was 9.6%. The reasons for revision, which always involved removal of the original implant, were acute worsening of low-back pain or lack of improvement (45 cases), recurrence of symptoms after an initial good outcome (42 cases), and implant dislocation (20 cases). CONCLUSIONS The IPD is not a substitute for a more invasive 3-column fusion procedure in cases of major instability and spondylolisthesis. Overdistraction, poor bone density, and poor patient selection may all be factors in the development of complications. Preoperatively, careful attention should be paid to bone density, appropriate implant size, and optimal patient selection.