fluorapatite and Postoperative-Complications

Background and purpose - Little is known about the long-term migration pattern of cementless stems in total hip arthroplasty (THA). Furthermore, the role of bioactive coatings in fixation, and thus migration, remains uncertain. Hydroxyapatite (HA) is the most commonly used bioactive coating. However, delamination of the coating might induce loosening. Alternatively, fluorapatite (FA) has proved to be more thermostable than HA, thereby potentially increasing longevity. We assessed the long-term migration of cementless stems with different coatings using radiostereometric analysis (RSA), thereby establishing a reference for acceptable migration. Patients and methods - 61 THAs in 53 patients were randomized to receive either a HA, FA, or uncoated Mallory-Head Porous stem during the years 1992 to 1994. Primary outcome was stem migration measured using RSA and secondary outcome was the Harris Hip Score (HHS). Evaluation took place preoperatively and postoperatively on the second day, at 6, 12, 25 and 52 weeks, and annually thereafter. At the 25-year follow-up, 12 patients (17 THAs) had died and 1 patient (1 THA) was lost to follow-up. Due to the high number of missing second-day postoperative RSA radiographs, the 1-year postoperative RSA radiograph was used as baseline for the comparative analyses. Results - Mean follow-up was 17 years (SD 6.6). All stems showed initial rapid migration with median subsidence of 0.2 mm (-0.1 to 0.6) and median retroversion of 0.9° (-3.2 to 2) at 12 months, followed by stable migration reaching a plateau phase. No stem was revised, albeit 1 stem showed continuous subsidence up to 1.5 mm. Comparing the different coatings, we could not find a statistically significant difference in overall 25-year migration (p-values > 0.05). Median subsidence at 15-year follow-up was for HA -0.1 mm (-0.4 to 0.2), for FA 0 mm (-0.1 to 0.2), and for uncoated stems 0.2 mm (-0.1 to 0.5). Median internal rotation at 15-year follow-up was for HA not available, for FA 1.1° (-0.5 to 2.6), and for uncoated stems 0° (-0.5 to 0.4). HHS were also comparable (p-values > 0.05), with at 15-year follow-up for HA 85 points (41-99), for FA 76 points (61-90), and for uncoated stems 79 points (74-90). Interpretation - The long-term migration pattern of cementless stems using different bioactive coatings has not previously been described. No beneficial effect, or side effect at long-term follow-up of bioactive coatings, was found. The provided migration data can be u

Topics: Aged; Apatites; Arthroplasty, Replacement, Hip; Coated Materials, Biocompatible; Durapatite; Female; Femur; Follow-Up Studies; Hip Prosthesis; Humans; Long Term Adverse Effects; Male; Postoperative Complications; Prosthesis Design; Prosthesis Failure; Radiostereometric Analysis

The removal of certain deformities of facial bones is a prerequisite to a restoration of function, stability, and appearance. Synthetic bone substitutes are beneficial in cases where other operative technique would represent an inadequate burden for a patient. A result is achieved in one surgical intervention with low costs and low demands on technical equipment. Biocompatible nonresorbable glass-ceramics based on oxyfluoroapatite and wollastonite presenting osteoconductivity permits osteointegration, i.e., direct physicochemical bonds between live bone tissue and the implant without formation of a fibrous capsule. It presents better durability to stress in simulated body fluid than the usually used hydroxyapatite. It was used for restoration of facial skeletal framework contour in 14 cases under conditions where prior solutions were doubtful. Good results were reached in all patients. The mean time of observation was 18 months. During that period, the rate of complications was 14.3%. This approach may be found to be a suitable technique, especially for patients exhausted by prior unsuccessful treatment but still not acquiesced in a result.

Topics: Adult; Apatites; Biocompatible Materials; Bone Diseases; Bone Substitutes; Calcium Compounds; Ceramics; Chemical Phenomena; Chemistry, Physical; Craniofacial Abnormalities; Crystallization; Facial Asymmetry; Facial Bones; Female; Follow-Up Studies; Glass; Goldenhar Syndrome; Humans; Mandibulofacial Dysostosis; Osseointegration; Osteogenesis; Postoperative Complications; Silicates; Treatment Outcome