Biological activity of the implant for internal fixation.

Early treatment of bone fractures was performed using implants, which are often used in the form of plates of various types, which are fixed on the bone surface (extracellular fixation) and nails that are located in the medullary canal (intracerebral fixation). The goal of this study was to investigate the features of osseointegration of implants for internal fixation (intramedullary or extramedullary) with various bioactive coating techniques. During experimental study on 20 mongrel dogs, the implant model in the form of 1.0-mm plate made of titanium alloy (Ti6Al 4V) was placed in the medullary canal (first series) or under the periosteum (second series): the plates had bioactive coating (hydroxyapatite) produced using the technology of magnetron sputtering (six animals), plasma electrolytic oxidation or microarc oxidation technology (PEO; eight animals), and composite technology (six dogs). Anatomic and histological studies have shown that the process of active osseointegration of porous implants with bioactive coating begins after 7 days: at first, granulation tissue - and then fibrous connective tissue - is formed; after 14 days, the osteogenic substrate can be found, and after 28 days, the entire implant area is covered by the lamellar bone tissue, which creates single implant-bone block. The most active formation of bone tissue is observed around implants with bioactive coating produced using the last two technologies. Low traumatic placement of porous implants with bioactive coating in the medullary canal or subperiosteally provides the stimulation of reparative osteogenesis and rapid (especially with PEO technique) osseointegration of the implant.

Gradual Metatarsal Lengthening by External Fixation: A New Classification of Complications and a Stable Technique to Minimize Severe Complications.

BACKGROUND: The surgical management of brachymetatarsia remains controversial, and choice is based on potential complications. We report a classification of complications based on severity, and we hypothesized that use of a semicircular external fixator would minimize severe complications in lateral metatarsal lengthening. METHODS: We retrospectively reviewed 30 patients (10 to 46 years old) with single or multiple brachymetatarsia and performed 54 metatarsal lengthenings with a mean follow-up of 7 months. RESULTS: The mean gain in length was 15 mm (33.7%), and the mean healing index was 67 d/cm. No further procedure was performed. No dislocations or subluxations were reported, but 26 complications (48.1%) occurred, classified as 1 severe (1.8% of the metatarsals), 5 intermediate (9.3%), and 20 benign (37%): 4 incomplete osteotomies, 8 adjacent metatarsal osteotomies, 2 involuntary adjacent metatarsal fixations due to the lack of fluoroscopy use, 6 early consolidations, 2 metatarsal fractures, 2 skin complications, 1 superficial infection, and 1 metatarsophalangeal clinodactyly. CONCLUSION: A classification of complications based on severity was developed. Gradual lengthening of the lateral metatarsals by semicircular external fixation reduced the risk of severe complications because of stability without donor site morbidity. Thin wires were an advantage in the pediatric population. LEVEL OF EVIDENCE: Level IV, retrospective case series.