Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.

Input: Consider Input: Abstract: Atlanto-axial rotatory fixation is one of a spectrum of rotatory abnormalities of the atlanto-axial joint. Rotatory fixation without anterior displacement of the atlas (Type I) has been reported in only a few cases in which there has been a prolonged interval between injury and diagnosis. The majority of these cases eventually required cervical fusion for persistent deformity or instability. Two cases are presented in which this diagnosis was made early with the aid of rotated odontoid radiographs, tomography and computerised axial tomography. Treatment by a short period of halter traction achieved reduction and early return of function. The authors conclude that early recognition and treatment of this rare condition may prevent the subsequent deformity and instability for which cervical fusion has been required.

Output: Atlanto-Axial Joint

Input: Consider Input: Abstract: The authors present an in-depth clinical, radiographic, and pathologic analysis of a 62-year-old man with massive bone reabsorption around the proximal femur in a total hip arthroplasty (THA). The THA was revised 13 years after implantation. Thirty millimeters of calcar resorption was noted radiographically. Evidence of stem bending was present on examination of the femoral implant, and marked wear of the acetabular cup was noted. The pathologic evaluation of removed calcar bone and cement revealed a histiocytic mass invading the bone. Intracellular and extracellular polymethylene debris was noted within the invasive mass. Evidence of fragmented methylmethacrylate cement was also present. The bone-cement interface in the excised calcar region contained segments that showed active bone remodelling around the cement without an interposed membrane. It is possible that this case of calcar resorption began with histiocytic activation and recruitment by polyethylene wear debris followed by active bone lysis. The process may be perpetuated by the fragmentation of cement, as motion occurred at the calcar bone-cement interface, and may represent an extreme example of a process occurring in cases of calcar resorption in general.

Output: Bone Cements

Input: Consider Input: Abstract: The records of 24 patients with malignant gliomas treated with carotid infusion of cisplatin and 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) are reviewed for risk factors that might suggest the development of a permanent neurological deficit after infusion. Permanent neurological deficits were seen with doses of cisplatin as low as 69 mg/m2, although doses as high as 100 mg/m2 were tolerated by other patients. All 3 patients who developed permanent neurological deficits received fixed doses of cisplatin of 150 mg and supplied only 2 major intracranial branches from the infused carotid artery. In none of these patients was a filter used in the infusion line. Other risk factors identified in 2 of the 3 patients were diffuse neoplasm involving the region of the internal capsule and the use of an infusion pump rather than a pulsatile bolus infusion technique. The development of a permanent neurological deficit appeared unrelated to the dose of BCNU within the range utilized, and preinfusion administration of corticosteroids did not prevent neurological deficit. These possible risk factors should be considered in the future development of protocols for arterial infusion therapy of malignant gliomas.
Output: Brain Diseases