A histologic analysis of the effects of stainless steel and titanium implants adjacent to tendons: an experimental rabbit study

A study on the effect of bioactive glass and hydroxyapatite-loaded Xanthan dialdehyde-based composite coatings for potential orthopedic applications

The most important challenge faced in designing orthopedic devices is to control the leaching of ions from the substrate material, and to prevent biofilm formation. Accordingly, the surgical grade stainless steel (316L SS) was electrophoretically deposited with functional composition of biopolymers and bioceramics. The composite coating consisted of: Bioglass (BG), hydroxyapatite (HA), and lawsone, that were loaded into a polymeric matrix of Xanthan Dialdehyde/Chondroitin Sulfate (XDA/CS). The parameters and final composition for electrophoretic deposition were optimized through trial-and-error approach. The composite coating exhibited significant adhesion strength of "4B" (ASTM D3359) with the substrate, suitable wettability of contact angle 48°, and an optimum average surface roughness of 0.32 µm. Thus, promoting proliferation and attachment of bone-forming cells, transcription factors, and proteins. Fourier transformed infrared spectroscopic analysis revealed a strong polymeric network formation between XDA and CS. scanning electron microscopy and energy dispersive X-ray spectroscopy analysis displayed a homogenous surface with invariable dispersion of HA and BG particles. The adhesion, hydrant behavior, and topography of said coatings was optimal to design orthopedic implant devices. The said coatings exhibited a clear inhibition zone of 21.65 mm and 21.04 mm with no bacterial growth against Staphylococcus aureus (S. Aureus) and Escherichia coli (E. Coli) respectively, confirming the antibacterial potential. Furthermore, the crystals related to calcium (Ca) and HA were seen after 28 days of submersion in simulated body fluid. The corrosion current density, of the above-mentioned coating was minimal as compared to the bare 316L SS substrate. The results infer that XDA/CS/BG/HA/lawsone based composite coating can be a candidate to design coatings for orthopedic implant devices.

Management of Comminuted Fracture of Mandible Using Titanium Mesh

Comminuted mandibular fractures are common following a high-velocity injury to the face and jaws. The inherent nature of injury and damage to the underlying hard and soft tissues often complicate the management of comminuted fractures. Traditionally, comminuted fractures were managed by closed reduction and external skeletal fixation. Titanium mesh serves as an excellent alternative in the management of comminuted mandibular fractures. The present case report presents the successful management of comminuted mandibular fractures using titanium mesh.

A systematic review of the use of titanium versus stainless steel implants for fracture fixation

Background:

Controversy exists regarding the use of titanium and stainless steel implants in fracture surgery. To our knowledge, no recent, comprehensive review on this topic has been reported.

Purpose:

To perform a systematic review of the evidence in the current literature comparing differences between titanium and stainless steel implants for fracture fixation.

Methods:

A systematic review of original research articles was performed through the PubMed database using PRISMA guidelines. Inclusion criteria were English-language studies comparing titanium and stainless steel implants in orthopaedic surgery, and outcome data were extracted.

Results:

The search returned 938 studies, with 37 studies meeting our criteria. There were 12 clinical research articles performed using human subjects, 11 animal studies, and 14 biomechanical studies. Clinical studies of the distal femur showed the stainless steel cohorts had significantly decreased callus formation and an increased odds radio (OR 6.3, 2.7-15.1; P < .001) of nonunion when compared with the titanium plate cohorts. In the distal radius, 3 clinical trials showed no implant failures in either group, and no difference in incidence of plate removal, or functional outcome. Three clinical studies showed a slightly increased odds ratio of locking screw breakage with stainless steel intramedullary nails compared with titanium intramedullary nails (OR 1.52, CI 1.1-2.13).

Conclusion:

Stainless steel implants have equal or superior biomechanical properties when compared with titanium implants. However, there is clinical evidence that titanium plates have a lower rate of failure and fewer complications than similar stainless steel implants in some situations. Although our review supports the use of titanium implants in these clinical scenarios, we emphasize that further prospective, comparative clinical studies are required before the conclusions can be made.

Proximal Phalanx Fracture Management

BACKGROUND

The goal of proximal phalangeal fracture management is to allow for fracture healing to occur in acceptable alignment while maintaining gliding motion of the extensor and flexor tendons.

METHODS

We reviewed the most current literature on various treatment methods of proximal phalanx fractures, focusing on the indications and outcomes of nonoperative as well as operative interventions.

RESULTS

Stable fractures can be successfully treated nonoperatively, whereas unstable injuries benefit from surgery. Regardless of the surgical intervention employed, the overriding goal is to restore anatomy and impart enough stability to allow for early motion. The surgical dissection contributes to soft tissue scarring and should be minimized.

CONCLUSIONS

Clinical success is achieved when acceptable fracture alignment and stability occur in the setting of unobstructed tendon gliding and early active range of motion.

Flexor tendon repair after rupture caused by volar plate fixation of the distal radius

Volar plate fixation of unstable fractures of the distal radius is preferred by a majority of surgeons today. One known complication is the rupture of flexor tendons. The aim of this paper is to present flexor tendon ruptures after volar plate fixation analysing the clinical outcome after tendon surgery, aetiology, and methods of prevention. Seventeen consecutive ruptures in 14 patients were included. The incidence was 1.4%. Three patients declined tendon surgery. Eleven patients were treated with a free tendon graft. Only two patients showed excellent results regarding mobility in the thumb and/or fingers. Analysis of radiographs demonstrated sub-optimal placement of plate or screws in all cases. Rupture of a flexor tendon is a serious complication where the functional outcome after surgical reconstruction is uncertain. Early removal of the plate when the placement is sub-optimal or when local volar tenderness appears would probably prevent many ruptures.

Distal radius volar locking plate design and associated vulnerability of the flexor pollicis longus

PURPOSE

Flexor pollicis longus (FPL) tendon rupture is a well-documented complication related to the use of distal radius volar locking plates (VLPs). The final common pathway of flexor tendon rupture appears to involve implants prominent at the watershed line. We hypothesized that significant differences in VLP prominence exist between various plate designs.

METHODS

Ten fresh frozen specimens were dissected to identify the path of the FPL in relationship to the distal radius at the watershed line. Five VLP designs were fixed to each specimen based on their anatomic fit, and slid distally until the distal edge of the plate reached the watershed line. The position of each fixed plate was evaluated by fluoroscopy. We used a 3-dimensional laser scanner to create computer models. The total surface area of plate prominence volar to the watershed line and the prominent area beneath the FPL were measured in the axial plane using computer software.

RESULTS

At the watershed line, the FPL was located at 54% of the maximal width of the radius, as measured from its volar-ulnar corner. There were no significant differences in the location of plate fixation on lateral view radiographs according to the classification of Soong et al. The mean total surface area of plate prominence was 36 mm(2). The mean prominent area beneath the FPL was 10 mm2. Significant differences in plate prominence were noted for various designs.

CONCLUSIONS

Despite optimal plate placement, various VLP designs were observed to have prominent profiles volar to the watershed line, to varying extents.

CLINICAL RELEVANCE

The results raise concerns regarding interference between all of the analyzed VLP designs and the FPL. This study may help guide both implant design considerations and assist the surgeon in better understanding implant morphology as it relates to iatrogenic flexor tendon injury.

Assessment of Cellular Reactions to Magnesium as Implant Material in Comparison to Titanium and to Glyconate Using the Mouse Tail Model

Purpose

Nowadays, research in magnesium alloys as a biodegradable implant material has increased. The aim of this study was to examine osteoinductive properties and tissue responses to pure magnesium in comparison to conventional permanent (titanium) and to degradable (glyconate) implant materials.

Methods

Magnesium wires (0.4 mm in diameter, 10 mm length) were implanted into tail veins of mice and examined after 2, 4, 8, 16 and 32 weeks. Titanium and glyconate as controls were assessed after 2, 4, 8 and 24 weeks. μ-computed tompgraphy, histology and SEM examinations were performed.

Results

Magnesium implants showed increasing structural losses over time with fragmentation after an observation period of 32 weeks. Glyconate was fully degraded and titanium remained almost unaffected after 24 weeks. In contrast to some titanium and glyconate implants, first calcium and phosphate precipitations could be observed around magnesium implants after two weeks. However, ossification could not be observed even after 32 weeks, whereas enchondral ossification was found partially in the sourrounding of glyconate and titanium implants after eight weeks. Nevertheless, magnesium implants showed less inflammatory responses and fibrosing properties than the conventional implant materials.

Conclusions

Although the assumed osteoinductive properties could not be detected, magnesium appears to be a promising degradable implant material because of the low sensitizing and inflammatory potential.

Plasma-sprayed hydroxyapatite coating on carbon/carbon composite scaffolds for bone tissue engineering and related tests in vivo

The bioactive hydroxyapatite (HA) coatings were successfully prepared on carbon/carbon composites (C/C) by means of sand-blasting pretreatment and plasma-spraying technology. X-ray diffraction was employed to analyze the phase constitute of the coatings. Meanwhile, the bond strength between the HA coatings and C/C substrates was determined via shear test. Experimental results show that the coatings constitute HA, CaO, and other amorphous phosphates. The post heat treatment could effectively increase crystallization and purity of the coatings. Through observation and analysis by electron microprobe and scanning electron microscopy, it is concluded that the bond strength of the plasma-sprayed HA coatings on C/C is mainly determined by the interface structure and can be further improved by the post heat treatment. Meanwhile, the implantation in vivo was carried out in hybrid goats. The histological observation revealed that the osteoplaque gradually grew on the surface of the HA coatings and the pure C/C surface was covered by the fibrous tissues. No inflammation symptoms were found in the bone tissue around the implants.

Plating for distal radius fractures

No area of fracture management has had such a recent explosion of new treatment modalities as distal radius plating. This explosion has largely been implant- and industry-driven, with little evidence-based research guiding the way. A perceived difficulty with commonly used modalities by the orthopedic community has been enough to drive an entire new set of options for distal radius fixation. A drift from dorsal to volar plating has occurred that has been unexamined by randomized research. Segment specific fixation has been a new mindset that has resulted in a novel plate line and has caused other manufacturers to redesign their product lines. Other novel approaches for proposed problems include locking plates, nail-plate combinations, and others. This article outlines some of these options with a literature opinion and a clarification from the authors. A treatment plan for common fractures of the distal radius is also outlined.

Release of metals from osteosynthesis implants as a method for identification: post-autopsy histopathological and ultrastructural forensic study

Metal structures--especially of stainless steel, titanium and their alloys (biomaterials)--are widely used in orthopaedic practice and the subject of constant study in bioengineering and preventive medicine. This study presents the first experience of forensic research into the presence of permanent tissue variations around metal implants in various bone structures for the purpose of identification, with particular reference to skeletal remains or severely decomposed corpses in the absence of other identifying elements. The evaluation was conducted on 12 corpses who had undergone osteosynthesis intra-vitam, whose implants were still in place or had been removed, in comparison with five controls who had never undergone osteosynthesis. Bone fragments taken during autopsy were subjected to histopathological and scanning electron microscope-energy dispersive electroscopy examination in order to reveal and characterise any metal particles originating from osteosynthesis. The study enabled the discovery of intra-bone metal particles in tissues treated by osteosynthesis even in bone areas where the implants had been removed and even where there were no longer any radiological signs of their application. These results are therefore of considerable forensic importance, especially in the area of identification, providing a valid means of recognition beyond that of the well-established use of in situ metal implants.

Operative management of distal radial fractures with 2.4-millimeter locking plates. A multicenter prospective case series

BACKGROUND

In the past decade, there has been a trend toward open reduction and internal fixation of unstable distal radial fractures. There are now more than thirty different implant designs specific for the fixation of distal radial fractures. A multicenter prospective study of a case series was conducted to determine the efficacy of the operative management of distal radial fractures stabilized with 2.4-mm locking plates.

METHODS

One hundred and fifty patients were entered into the study over a two-year period. The mean age of these patients was fifty-one years, and the cohort included eighty-eight women and sixty-two men. Eighty-six patients sustained a low-energy injury. Seventy-one percent of the fractures in the series were intra-articular and were Type C according to the Müller-AO Comprehensive Classification. The follow-up evaluations, which were conducted at six weeks, six months, one year, and two years, included assessments of pain, motion, grip strength, and standard radiographs. Gartland and Werley scores were recorded at six months and one and two years, and Disabilities of the Arm, Shoulder and Hand (DASH) scores were recorded at one and two years.

RESULTS

One hundred and twenty-five patients (83%) had a complete follow-up at six months; 121 (81%), at one year; and 117 (78%), at two years. Significant improvements in motion, grip strength, and patient satisfaction were observed between six months and one year, but further improvements were not seen at the two-year follow-up examination. The mean DASH score changed from a preinjury baseline of 2 points to 8 points at one year and 7 points at two years (p < 0.0001). The mean Gartland and Werley score improved significantly from 4 points at six months to 2 points at two years. Of the 102 intra-articular fractures examined in the immediate postoperative period, twenty had a step-off of < or =2 mm and seven had a step-off of >2 mm. Of the seventy-one intra-articular fractures seen at two years, sixty-one had no step-off, five had a step-off of < or =2 mm, and five had a step-off of >2 mm. Twenty-seven percent of the patients showed an increase of at least one grade in radiographic signs of arthritis at two years. There were twenty-eight complications, twenty of which were considered minor. Tendon inflammation occurred in nine patients. There were two tendon ruptures, one of which was due to a prominent dorsal screw tip placed through a volar plate and one of which was due to a prominent volar plate. Loss of reduction occurred in two patients, and screw loosening occurred in two patients.

CONCLUSION

Internal fixation of displaced distal radial fractures with implants featuring locking screw fixation can result in good-to-excellent outcomes with a limited number of complications.

Fatigue testing of three peristernal median sternotomy closure techniques

BACKGROUND

Failure of a sternotomy closure because of closure system fatigue is a complication that may result in dehiscence and put the individual at risk for serious complications. The purpose of this study was to assess the fatigue performance of three peristernal median sternotomy closure techniques (figure-of-eight stainless-steel wires, figure-of-eight stainless-steel cables, or Pectofix Dynamic Sternal Fixation [DSF] stainless-steel plates) in order to quantify the potential risk of fatigue failure of these devices when subject to cyclic loads in physiologically relevant loading directions.

STUDY DESIGN

All tests were conducted on polyurethane foam sternal models. A cardiothoracic surgeon divided each sternal model longitudinally and repaired it with a closure device. Tests were performed using a materials testing system that applied cyclic loading in a uniaxial direction until the test model catastrophically broke or data run-out occurred. For each loading direction (lateral distraction and longitudinal shear), five trials of each closure technique were tested. Life data and location of device failure (if present) were evaluated. Statistical analysis was performed using regression with life data allowed for correlation between life data and the various closure techniques to develop risk assessment curves for each device.

RESULTS

The data show that the figure-of-eight stainless-steel cable and the DSF plate systems are considerably less likely to fail under both lateral distraction and longitudinal shear cyclic loading conditions as compared to the figure-of-eight stainless-steel wire system. Moreover, the figure-of-eight stainless-steel cable system is the most resistant to failure, particularly for high cycle counts.

CONCLUSION

This study in addition to Cohen and Griffin's earlier published biomechanical comparison of the ultimate strength of these same three closure techniques provide extensive experimental evidence regarding the mechanical differences among these three peristernal median sternotomy closure techniques. All data support the hypothesis that both the DSF plate system and the stainless-steel cable system offer important advantages over figure-of-eight wire closure techniques; although twisted wires are the weak-link in the systems we tested.

Corrective osteotomy for deformity of the distal radius using a volar locking plate

Dorsally angulated malunions of the distal radius have historically been corrected with an opening wedge osteotomy fixed with a dorsal plate. Volar locking plates may facilitate a less morbid approach to corrective osteotomies of the wrist. Eight consecutive patients with an average age of 40 years (range, 15-52 years) underwent correction of a distal radius deformity through a volar approach. Clinical follow-up averaged 17.4 months (range, 7-41 months). Preoperative radiographs revealed an average of 24 degrees of dorsal tilt in patients with dorsal deformity. Postoperatively, their average measurement was <3 degrees of volar tilt. Patients were initially ulnar-positive with an average of 4 mm ulnar-positive variance (range, 2-7 mm). This corrected to less than 1 mm postoperatively. Postoperative disabilities of the arm, shoulder, and hand (DASH), SF-12, and Mayo Wrist scores averaged 10.8, 40.5, and 82.5, respectively. There were no nonunions, and no plates required removal. Distal radius deformity can be effectively addressed through a volar approach with the use of a locking plate.

Plating for distal radius fractures

No area of fracture management has had such a recent explosion of new treatment modalities as distal radius plating. This explosion has largely been implant- and industry-driven, with little evidence-based research guiding the way. A perceived difficulty with commonly used modalities by the orthopedic community has been enough to drive an entire new set of options for distal radius fixation. A drift from dorsal to volar plating has occurred that has been unexamined by randomized research. Segment specific fixation has been a new mindset that has resulted in a novel plate line and has caused other manufacturers to redesign their product lines. Other novel approaches for proposed problems include locking plates, nail-plate combinations, and others. This article outlines some of these options with a literature opinion and a clarification from the authors. A treatment plan for common fractures of the distal radius is also outlined.