The effect of ultraviolet photofunctionalization of titanium instrumentation in lumbar fusion: a non-randomized controlled trial

Abstract

Background Titanium instrumentations are widely used in orthopedics; the metal bonds with bone in a process called osseointegration. Over time, hydrocarbons adhere to the instrumentation, which weakens the bone-binding ability. Ultraviolet photofunctionalization enhances the bone-binding ability of instrumentation by reducing hydrocarbons. The process has been proven effective in dentistry, but its effects in orthopedics are unverified. We aimed to determine the effect of ultraviolet photofunctionalization of titanium instrumentation used in lumbar fusion. Methods This was a non-randomized controlled trial. We prospectively enrolled 13 patients who underwent lumbar fusion surgery. We inserted two pure titanium cages into each intervertebral space; one cage had undergone ultraviolet photofunctionalization, while the other was untreated. The degree of osteosclerosis around both cages was then compared by measuring the densities around the cages on imaging at 2, 3, 6, and 12 months postoperatively compared with 1 month postoperatively. The carbon attachment of the titanium cages was measured using X-ray photoelectron spectroscopy. Results There was no significant difference between the degree of osteosclerosis (as assessed by the density) around the treated versus untreated cages at any timepoint. The ratio of carbon attachment of the titanium cages was only 20%, which was markedly less than the ratio of carbon attachment to titanium instrumentation previously reported in the dentistry field. Conclusions The effect of ultraviolet photofunctionalization of titanium instrumentation in spine surgery is questionable at present. The biological aging of the titanium may be affected by differences in the manufacturing process of orthopedics instrumentation versus dentistry instrumentation. Trial registration UMIN Clinical Trials Registry (Identifier: UMIN000014103 ; retrospectively registered on June 1, 2014).

An Integrated Overview of Ultraviolet Technology for Reversing Titanium Dental Implant Degradation: Mechanism of Reaction and Effectivity

“…The literature search did not yield any randomized controlled clinical trials or prospective studies relevant to photofunctionalization other than seven (7) retrospective studies including a case series and case report. There was one (1) clinical trial on the photofunctionalization of titanium in orthopedic patients [91]. No direct data analysis was attempted, as clinical case reports do not provide an adequate source of evidence.…”

Clinical Applications of Photofunctionalization on Dental Implant Surfaces: A Narrative Review

“…Additional hydrocarbons on titanium implant/instrument surfaces decreases bone-binding ability by aging [ 22 ]. However, PhF could promote osseointegration by reducing hydrocarbons [ 22 , 33 ].…”

“…After abstract review, there were two double-blind clinical trial studies, three prospective studies, four retrospective studies, and one case series in the present paper [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. Furthermore, PhF applied in the spine surgery of 13 patients was included [ 22 ]. Except for some pre-clinical review papers on in vitro or animal studies, to my best knowledge, this paper is the first review focused on the clinical application of photofuctionalization [ 4 , 23 , 24 , 25 ].…”

Surface treatment of 3D printed porous Ti6Al4V implants by ultraviolet photofunctionalization for improved osseointegration

“…Photofunctionalization, which involves the use of ultraviolet (UV) treatment to modify titanium surfaces, has been shown to enhance bone-implant contact by changing the biological and biochemical properties of titanium [ [17] , [18] , [19] ]. It has been reported that titanium surfaces undergo a significant decrease in osseointegration capability after processing, which is associated with the disappearance of hydrophilicity [ 20 ], the progressive contamination of hydrocarbons [ 21 ], and the electrostatic status change on titanium surfaces over time [ 22 ].…”

“…Moreover, there is no UV irradiation equipment specifically for 3D-printed porous Ti6Al4V implants currently available. As UV photofunctionalization is effective on various titanium surfaces without altering their original topography or other morphological features, we specially designed a device targeted at the UV treatment of 3D-printed porous Ti6Al4V implants for osseointegration improvement [ [17] , [18] , [19] , [20] , [21] , [22] , [23] ].…”