ABSTRACT
STUDY DESIGN: A 1-year-old calf was implanted with titanium pedicle screws either uncoated (n = 7) or coated with hydroxyapatite (n = 7) by the dipping method on the pedicles of vertebrae (t10-l3). OBJECTIVE: To evaluate biomechanical and histomorphologic responses to titanium pedicle screws uncoated and coated with hydroxyapatite. SUMMARY OF BACKGROUND DATA: Failure of fixation caused by loosening of pedicle screws is a problem in spinal surgery. Enhancement of the fixation ability of screws by coating with biocompatible materials may improve prognosis of surgery. METHODS: The calf was euthanized 4 months after implantation for determination of insertion and extraction torques for screws, and histologic and scanning electron microscopic examinations of areas screw embedded. RESULTS: Insertion torques did not differ by the kind of screws (99 +/- 5.7 Ncm). However, extraction torques for screws coated with hydroxyapatite were higher than for screws uncoated (249 vs. 133 Ncm, P < 0.01). As compared with uncoated screws, implanted areas for hydroxyapatite-coated screws were denser, had more cracks, and provided better bonding. Fibrous tissue and new bone formation were observed around the areas of uncoated and hydroxyapatite-coated screws embedded, respectively. CONCLUSIONS: Hydroxyapatite coating of titanium pedicle screws by the dipping method improved fixation and vertebral bone-implant interface, suggesting a decreased risk of a screw-loosening problem.
Subject(s)
Bone Screws , Coated Materials, Biocompatible , Durapatite , Titanium , Animals , Bone Screws/standards , Cattle , Coated Materials, Biocompatible/standards , Durapatite/standards , Lumbar Vertebrae/surgery , Lumbar Vertebrae/ultrastructure , Models, Animal , Thoracic Vertebrae/surgery , Thoracic Vertebrae/ultrastructure , Titanium/standardsSubject(s)
Acetabulum/physiopathology , Arthroscopy/methods , Osteochondritis Dissecans/diagnosis , Osteochondritis Dissecans/surgery , Adult , Female , Follow-Up Studies , Hip Joint/physiopathology , Humans , Magnetic Resonance Imaging , Pain Measurement , Recovery of Function , Risk Assessment , Severity of Illness Index , Tomography, X-Ray Computed , Treatment OutcomeABSTRACT
UNLABELLED: We studied the effect of intraarticular saline, sufentanil, or sufentanil plus methylprednisolone after knee arthroscopic meniscectomy. In a double-blind randomized study, 60 patients undergoing knee arthroscopic meniscectomy were allocated to groups receiving intraarticular saline, intraarticular sufentanil 10 microg, or sufentanil 10 microg plus methylprednisolone 40 mg at the end of arthroscopy during general anesthesia. Postoperatively, pain levels at rest and during movement (i.e., active flexion of the knee) were measured by a visual analog scale and were significantly decreased in the sufentanil and sufentanil plus methylprednisolone groups compared with the control group. Moreover, we found that there was a significant reduction in intraarticular sufentanil and sufentanil plus methylprednisolone in the postoperative consumption of analgesics. We also found that the use of intraarticular sufentanil or sufentanil plus methylprednisolone after knee arthroscopic meniscectomy decreases the amount of supplementary analgesic needed for pain relief during the early postoperative period. In addition, we detected that sufentanil provided prolonged pain relief up to 24 h when compared with control, whereas when we combined sufentanil plus methylprednisolone, we found that it further reduced pain and use of analgesics when compared with sufentanil. IMPLICATIONS: The combined use of intraarticular sufentanil (10 microg) and methylprednisolone (40 mg) in arthroscopic meniscectomy surgery reduced both postoperative pain scores and the use of additional analgesics.
