ABSTRACT
Polymethylmethacrylate bone cement is often used to fill voids and increase the strength of osteoporotic and pathological bone. However, it is unclear as to which method of cement augmentation provides optimal screw fixation. This study was conducted to determine which of the current cement augmentation techniques provides the strongest construct when used in association with orthopaedic fixation screws. Pullout strength was determined for screws placed in sawbones with no cement, soft cement, doughy cement and hard cement after drilling and tapping. All cement-screw constructs were significantly stronger than the no cement group. Screws placed in doughy cement had a significantly higher pullout force than those placed in hard cement. Pullout strength of screws placed in soft cement was intermediate between the other cement techniques but not significantly different from either group.
Subject(s)
Bone Cements/chemistry , Bone Screws , Methylmethacrylates/chemistry , Biocompatible Materials , Biomechanical Phenomena , Bone Cements/standards , Bone Screws/standards , Femur/physiologyABSTRACT
In summary, intramuscular myxoma associated with fibrous dysplasia of bone represents a benign disorder of uncertain etiology. Magnetic resonance imaging has proved to be a useful diagnostic tool in the evaluation of this benign disorder. In addition, MR is a valuable aid in the preoperative planning process.
Subject(s)
Femur , Fibrous Dysplasia of Bone/diagnosis , Myxoma/diagnosis , Soft Tissue Neoplasms/diagnosis , Thigh , Aged , Female , Fibrous Dysplasia of Bone/pathology , Fibrous Dysplasia of Bone/surgery , Humans , Magnetic Resonance Imaging , Myxoma/pathology , Myxoma/surgery , Soft Tissue Neoplasms/pathology , Soft Tissue Neoplasms/surgery , SyndromeABSTRACT
Hypoxemia has previously been reported during lumbar puncture (LP) in infancy. The purpose of this study was to determine whether preoxygenation before the LP would reduce hypoxemia during the procedure in infants. Twenty-one infants (one to 15 weeks of age) undergoing LP for evaluation of possible sepsis were randomly assigned to the control group (12) or treatment group (9). The treatment group was preoxygenated breathing oxygen (FiO2 = 1.0) spontaneously via snug face mask for three minutes prior to being positioned for the LP. The control group spontaneously breathed room air during this interval. Oxyhemoglobin saturation was measured prior to, and continuously during, the LP with pulse oximetry. The groups were comparable in age, resting respiratory rate, baseline saturation, and duration of the procedure. The treatment group developed significantly less desaturation during the procedure than the control group (P < 0.05). We conclude that preoxygenation prior to LP prevents most of the hypoxemia resulting from the procedure in infants.
